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Relative Inductance Analyzer (RIA) User`s Manual - us

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1. 4000 750 500 250 n 250 500 750 1000 Field 0e Figure 19 Example of MMT test output Transverse magnetic field is swept in two directions The bottom trace is the delta inductance between two sweeps Transverse magnetic field is first swept from 1000 to 1000 Oe and the second sweep 15 from 1000 to 1000 Oe The inductance traces are shown on the top the bottom trace reports the difference of inductance between two measurements The noisy delta signals in the small field range 250 to 250 Oe is caused by multilayer lamination of the pole structure The maximum delta inductance would be used for head diagnostics whereas if it exceeds an acceptable level the write head is reported as hysteretic Page 81 RIA User s Manual Integral Solutions Int l March 31 2010 20 8 YHDFT and YHDIT Yoke Domain Tests Field and write current patent pending These tests are also looking at the hysteresis effects and domain lock ups in the yoke In order to detect hysteresis effects multiple cycles of inductance measurements are run at a remanent state after consecutive application of DC write current and or magnetic field 0 775 0 750 0 725 Relative Inductance rH 0 025 0 000 Delta Inductance 0 775 YHDIT 1 Yoke Hysteresis Domain I Bias Test Pos head9 2 31 26 Neg head9 2 31 26 PM Delta head
2. erum 37 8 2 dtr hei M e ML M SRT 38 8 3 EXAMPLE PRINTOUT m utu Wa 39 9 u u uu 40 9 1 Q E e nu 40 9 2 PE BD asa am amma 40 9 3 ie lO metum ma n tur o 41 10 TMFT TILTED MAGNETIC FIELD TEST 42 10 1 utu LEM MD M MM M p EIL 42 DS o uyu DUC RP ME EE M AC n P IM DER M RE n RM M LI UTE 42 0 4 EXAMPLE PRINTO Tann Tau nw E a ate ctr LED CM ME EDU UM M 43 RIA User s Manual Integral Solutions Int l March 31 2010 1 WAT YOKEANISOIROPY TEST 22 coe donee eoe 44 11 1 SE UP PAR AVE TER ma 44 LEZ Pi O DEP a 45
3. 61 18 3 HALL EFFECT 00 00 9 61 18 4 QUAD POLE MAGNET CALIBRATION ADAPTOR 62 TROUBLESHOOTING zx iluy i 63 63 20 APPENDIX A RIA MEASUREMENIS 64 20 1 PERPENDICULAR WRITE HEAD 020000000000000000000000 64 20 2 INDUCTANCE SATURATION USING DC WRITE CURRENT LSA TI TEST 67 20 3 INDUCTANCE SATURATION IN MAGNETIC FIELD LS ATF TEST PATENT PENDING 69 20 4 CYCET COIL YOKE COUPLING EFFICIENCY TEST PATENT PENDING 73 20 5 YOKE DEFECT TEST PATENT 0000 0 0 enne nenne sene nne e enn sene e 75 20 6 YAT YOKE ANISOTROPY TEST PATENT 22 0000 0000 TI 20 7 MMT MAGNETIC MEMORY TEST PATENT PENDING a 91 20 8 YHDFT AND YHDIT YOKE DOMAIN TESTS FIELD AND WRITE CURRENT
4. Delta Inductance Clear Results Plot Reset Temporary oom Show All Curves Chart Scale Figure 13 2 YHDFT Example Printout Page 49 RIA User s Manual Integral Solutions Int l March 31 2010 14 YHDIT Yoke Hysteresis Domain I Bias Test The YHDIT applies positive and negative write current for a specified number of cycles and monitors writer inductance The test reports writer inductance at positive negative write current and the difference between them Fixed field can be applied during this test User can also specify field angle and the number of measurements to take an average from in each cycle ER YHDIT 1 Yoke Hysteresis Domain I Bias Test u Bl gt Grade Cycles Test Time Test Date Part IDC 100 11 415 1 7 2005 185444 Cycles 100 YHDIT 1 Yoke Hysteresis Domain Test Averages Fos t 5 54 44 PM Neg 6 5 54 44 PM Deta 56 54 44 PM Field Magnitude Field Angle 0 358 0 58 0 386 Fre Conditioning Figure 14 1 YHDIT Parameters 0 355 Inductance 14 1 Setup Parameters Cycles The number of times to toggle the field one cycle is set positive field and then set negative field Average This is how many measurements to take an average from at each cycle and field Each point on
5. buah 12 2 5 m AM MM EE MM I MEE CI M MEE 13 2 6 INSPAEDINGA RUA UPGRADE uu rero bd SIR D MEE MEER Ep idi bed MU 14 3 TESLER BASIC 5 Z unu unus 18 3 1 STARTING SOF TW ARE is e Une dentes reo e ovn 20 3 2 TA 21 3 3 ISUNNING TESTS Sac ea ae T 22 3 4 WRITERS PROFE 23 3 5 REIA 2008 CUSTOMSTPERSS uy u ua u idee UE 24 3 6 yin itecto 25 3 7 RUNNING RIA ON BLAZERX6 AND WAFER 26 4 28 4 1 SETOPPARAMETERS w Mot mA M 28 4 2 FPE pi AL M t LM 29 5
6. _ 100 11 415 YHDIT 1 7 2005 185444 Cycles YHDIT 1 Yoke Hysterezis Dormain I Bias Test Averages Pos 8 54 44 Meg 6 54 44 amp 6 54 44 Write Current m 51 Field Magnitude 0 j l Field ngle deg 000 GE IN 28 awia AEC eye ee D m D a x m we E Hysteresis U UU 19 26168 Delta Inductance LLL LA LLL W bela Clear Results Plot Reset Temporary oom Show All Curves Chart Scale Figure 14 2 YHDIT Example Printout Page 51 RIA User s Manual Integral Solutions Int l March 31 2010 15 MMT Magnetic Memory Test The MMT sweeps field field angle or write current in one direction and then in the opposite direction and shows if there is any difference between the two sweeps The test helps expose residual inductance value caused by applying field angle or write current 1 Magnetic Memory Test ioj xi Hd Grade Cycles Time Test Date Time Partio Hd NA 254 MMT 1772005 1985457 O Sweep T ME 1 Magnetic Memory Average Ss Write Current m 40 For m S PM Fev ay PM Deta TES 5 Field Angle deg Fre Conditioning Field Oe 250
7. Transverse 4 Transverse 10m Add Remove Hd Grade Test Time Date 4 f Quasi 37 Hd k Cycles 1 Multiple Curves k SR1U Fald ay A Tine 10 Fald 1 20 20 mA T V Stress Each Cycle Symmetrical H m i 250 Inc 10 0 d Static Tests Stress Options i E BIT mim Use Default Step Static Tests s System 5et B Sweep Test uae Production y 1z Results Extra Result ME Write Profile 5 Bias Current 0 0 000 B k 5 ampling Test 1 START Button Run Test Buton Resistance Ohms DD HEAD SELECT j _ Abort Test START Run Test Head 3 IUe ei ed pun Figure 3 7 Running the Tests To log results open the log file File Open Log File and set up the data logging options Statistics Raw Data Plots are some of the options available for logging You can run multiple tests at once by using the Production Test The production test will run a sequence of tests defined on the production menu on each enabled channel Refer to External Tests Users Manual for more information on the test details Page 22 RIA User s Manual 34 Writer Specific Tests The RIA 2008 adds more tes
8. 12147200 15 3615 Iterations 50 Field De 0 Write Current mA 20 Resistance 1 Fre Conditioning Results Data Farameters Grades Figure 16 1 Writer_Res Parameters 16 1 Setup Parameters Iterations The number of measurements to take to calculate AVG resistance Minimum 15 1 and maximum is 1000 with the default set to 3 Each measurement will be shown under the DATA tab and on the plot Field Oe The field in Oe at which the test should measure the writer resistance This is limited to maximum field specified in the system menu Write Current mA The write current to be applied during the test 16 2 Results Resistance ohm Writer resistance Page 54 RIA User s Manual Integral Solutions Int l March 31 2010 16 3 Example Printout Writer_Res 1 Writer Resistance Measurement Grade Cycles Test Time T est Date Time PHa n 137 174241530450 00 12 E 1 L1 4 ri hl 137 tinker Dd 1 4 nri E 307 4 FE Writer Res 1 Writer Resistance Measurement Field 0 Write Current 20 3 38 15 PM B 71 Pre Conditioning 6 705 5 700 5 595 Parameters Grades OC Coe 17 RAE 6 670 a a ea tm a LE 6 665 6 560 6 655 6 650 Clear Reset Temporary oom Figu
9. Move Bar Video Alignment m Loaded Holding Probing 2 Holding Height REFRESH COUNTER vacuum i Figure 3 17 RIA and Barcont In wafer application operator should use special intermediate board assembly with SMC connector going to writer pogo pins The RIA should be connected to the SMC connector on the intermediate board and RIA2008 application should be enabled in Quasi97 Add ins Selected Modules User would then be able to align the probes to the writer pads and commence testing as usual Page 27 RIA User s Manual Integral Solutions Int l March 31 2010 4 RIA 2008 Setup RIA 2008 Setup contains the setup parameters for measuring baseline inductance of the head The purpose of this test is to measure raw inductance of the write head while it is saturated cannot run on its own but other RIA 2008 tests will use it to calculate the LSATOffset parameter LSATF and other test will subtract the LSATOffset from the inductance value before reporting the results a x Hd Grade Cycles Test Time Test Iterations Preconditioning only i Saturation Field 3000 Write Current m Fre Conditioning RIA 2008 Setup 0 180 Results Data Parameters Grades Figure 4 1 RIA 2008 Setup In the backg
10. seaweeds ERE akapa LEES LE VR YEN 21 FIGURE 3 3 dut Deua Faden rebua Pa Bue ua 21 FIGURE HEADS ELECTION 21 FIGURE 3 7 RUNNING THE TESIS l a 22 FIGURE 23 PIGURE 3 9 ADAPTIVE PARAMETERS eorr ettet od aee werte bayi vea aa asa banda A br eoi 23 FIGURE 3 IO RIA 2008 CUSTOM STRESS tuo t et AE Ee 24 FIGURE 2 1 RIA 2008 RUNTIME DIGCENSE L Q u u u dava base ba eoo stas da dele re bes 25 FIGURE TZ RIA2Z008 SERIAL NUMBER un ka Pudet dur upp pai 25 FIGURE 3213 RIA2008 EVALUATION apu uv ORE 25 BLAZER uu u y n 26 FIGURE 9515 ALTERNATIVE TEST SITE ET ei n u u w eens 26 FIGURE 3 16 RIA ON BLAZERX5 PRODUCTION TEST 11 27
11. Sweep From 2000 2000 Inc 100 FE fp Figure 15 1 MMT Parameters Discrete Juctance rH Test can only sweep one parameter at a time The sweep parameter is selected by the user There are write current field angle and field settings but one of those will not be used depending on what sweep parameter is selected For example if field sweep is selected then Field Oe will not be used The sweep pattern can be set by specifying from to and increment or by setting discrete values The sweep pattern can go from negative to positive or back the increment can stay positive all the time As a result the test will show forward sweep as a solid medium thickness line reverse sweep as a dashed medium thickness line and the difference between the two as a thick solid line The test supports multiple setups so if for example user needs to sweep both the field and the angle then another setup of the test can be added and different sweep parameter selected there Test also supports display of multiple results on the same plot Different runs will be discriminated by color 15 1 Setup Parameters Sweep Field This tells the test which parameter user would like to sweep Angle WriteCurrent Choices are Field Angle or Write Current For the parameter that is being swept but single setting will be grayed out Average This is how many measurements to take at each field Note that this par
12. 1 Shorter yoke amp 08 Lower cc 0 6 0 4 x m d 0 2 0 500 1000 1500 2000 2500 Field Figure 7 Comparison of LSA TF plots for two different head designs Longer yoke head has higher inductance When sliders of the same design are analyzed e g on the bar level a variation of magnetic properties becomes evident The next figure shows LSATF plots taken on the same type of heads Relative inductance levels are similar however the position of the second kink shown by oval area varies from head to head in the range of approximately 150 Oe These shifts correspond to variation of the yoke permeability which can be caused by different reasons material properties stress etc For this type of write heads the kink position correlates with head performance the stiffer the yoke larger field kink the smaller the overwrite and track width One particular head has a pronounced difference of inductance and LSATF plot shape red plot This slider qualified as no writing in dynamic test Page 70 RIA User s Manual Integral Solutions Int l March 31 2010 2 Flare Region 1 6 Y V IB e Main pole head head B un permeability kx variation c N 7 0 6 4 N 0 2 AC 5 500 1000 1500 2000 2500 Field Oe Figure 8 Variation of LSATF tes
13. Q 42 FIGURE 022 IMET ESGAMPEB PRINTOUT ull il a DUREE MERE EUER 43 EIGURE LIST Y AT PARAMIETPERS 44 FIGURE EL GS uu a amuta amani 45 FIGURE 121 SWEEP PARAMETERS cid eiie e 46 FIGURE 12 22 Y XT SWEEP EXAMPLE PRINTOUT d us Re PEE TH 47 FIGURE 135 y uu l oe hapus a 48 FIGURE 3 2 Y HIDE EXAMPLE PRINTOUT DR o ee kanaa dai 49 FIGURE 1421 Y HDED PARAMETERS 50 FIGURE 422 Qua a t S an u 51 FIGURE 152 D NIME PARAMETERS eta catus Rau tu Eos bee ou E EO 52 FIGURE 15 2 MMT EXAMPLE PRINTOUT c ccccccssccsccccsccecsccessccesccceucceusscusescussseesscesescueseuscseescsessscesscescseescseuescucseuscsenes 53 FIGURE 16 1 WRITER RES PARAMETERS
14. DC Write Current mA Relative Inductance rH 40 45 DSO 55 60 O Figure 12 CYCET plots for good top and low efficiency bottom write heads The top graph corresponds to write head with good coil yoke efficiency Relative inductance is increased by 50 at 10 mA current The graph at the bottom corresponds to a low efficiency write head the same level of relative inductance is achieved at 18 mA The CYCET plot typically correlates with dynamic testing results in that the smaller values of DC current required to achieve a given inductance level correspond to heads with better OW Page 74 RIA User s Manual 20 5 YDT Yoke Defect Test patent pending Integral Solutions Int l March 31 2010 This YDT test is complimentary to the LSATF test and reports two inductance field saturation sweeps taken for transverse and longitudinal cross track magnetic field orientations Relative Inductance Relative Inductance 0 8 0 6 0 2 0 Cross track X gt o4 perpendicular 0 0 8 0 6 0 4 0 2 0 500 1000 Field 1500 Yoke defect 2500 ck perpendicular 0 Field Oe 200 400 600 800 1000 1200 1400 1600 1800 2000 Figure 13 YDT example for good top and defective bottom write heads
15. RESET PLL Calibrate Inductance Inductance avg 1 5 232 Inductance avg 1 5 291 Inductance avg 1 5 232 Please write this ta EEPROM v Inductance Calibration found Gain 0 485553 0 Backup File write Inductance avg 1 3 213 Page 56 RIA User s Manual 17 2 Magnet Integral Solutions Int l March 31 2010 The magnet has two calibration factors one for transverse coil and the other one for longitudinal The calibration factors can be found on a sticker outside of the magnet These are stored in the QPS Splitter eeprom and are set in Quasi97 automatically When receiving the upgrade it may be necessary to update the field gain factor in the QST 2002 Mainboard eeprom 1 2 3 Go to Quasi97 Diagnostics quad pole magnet sticker 4 5 Also change magnet resistance to 0 Click Write EEPROM button to save this Double click in the center of the menu and enter the password Quasi97 In the mainboard eeprom on the left change the Magnet Gain to 350 or whatever it says on the the This will help avoid Maximum Field out of range error message during loading of a setup file To do this Field calibration for the Quad pole magnet cannot be done in Quasi97 use QPS Splitter software instead To access QPS Splitter menu run QPS Splitter application by itself go to Quasi97 Add Ins Peripherals Field Splitter Then go to Diagnostics menu from there to calibrate the m
16. Temporary oam Show All Curves Chart Scale Figure 10 2 TMFT Example Printout Page 43 RIA User s Manual Integral Solutions Int l March 31 2010 11 YAT Yoke Anisotropy Test The YAT test rotates the field while keeping the same field magnitude and measures inductance of the writer at each field angle Before displaying the results the test subtracts the LSATOffset from each data point which is inductance measured with RIA 2008 Setup parameters ES 1 Yoke Anisotropy Test B gt 8 906 cycles Test Time Dat Time 084 2222 LI J 1 2 t 0 YAT 1 Yoke Anisotropy Test dcn dd Field Magnitude 500 6 52 35 Field Angle Sweep From 50 30 Inc Discrete Critical value s 50 Fre Conditioning TH e 11 1 YAT Parameters The field angle can be negative positive and zero The sweep pattern can be set by specifying from to and increment or by setting discrete values The sweep pattern can go from negative to positive or back The test can extract the field angle where the inductance value reaches critical value The critical value threshold or thresholds are user defined For example the test can return the field angle where inductance reaches 5090 To do this the test will find the maximum and minimum inductances m
17. i Relative Inductance Analyzer User s Manual AN Integral Solutions Intl RIA 2008 version 1 2 2 March 31 2010 Copyright 2009 2010 Integral Solutions Int l rights reserved Integral Solutions Int l 3000 Olcott St Santa Clara CA 95054 Phone 408 653 0300 Web http www us isi com Fax 408 653 0309 E mail 1s1 us 1si com While every effort has been made to verify the accuracy of the information contained in this publication this publication may contain technical and or typographical errors Please contact Integral Solutions Int l to report any errors in this publication RIA User s Manual Integral Solutions Int l March 31 2010 Contents 1 INTEOQODUC TIDN 2 9 5 5 4 Rn E RE 6 1 1 RELATED DOCUMENTATION L uuu kamaka eee ashes 7 2 INSTALLATION Di wu uD D sy 8 2 1 RE RINE Sak e io daha Sa iwa 8 2 2 ARRA AEC FECTS Puyu um D 10 2 3 m ask am 10 2 4 CONNECTION DIACGRE ANM a
18. nca I CAT 1 1 1 Inductance Saturation Test Preconditioning only Saturation Field a r 47 2 6530 2 6875 l l LIA Write Current 40 Fre Conditioning Results Data Parameters Grades Figure 5 1 LSAT Test 2 6570 Oat This test is multi setup capable which means that user create more than one setup of this test in MDS file LSAT also does not clear results automatically which allows user to see different runs superimposed on the plot 9 1 Setup Parameters Iterations The number of measurements to take to calculate AVG inductance Minimum is and maximum is 1000 with the default set to 10 Each measurement will be shown under the DATA tab and on the plot Field Oe The field in Oe at which the test should measure the writer inductance This is limited to maximum field specified in the system menu Writer inductance changes with external field but the response is not linear At higher fields the response inductance vs field is almost flat this 15 where the head 1s saturated This field value should be used to for LSATOffset calculation Write Current mA The write current to be applied during the test Typically this is not necessary the field alone is enough to get the saturation value However this test is also the place where user can measure writer
19. 20 0 20 40 60 Current mA Figure 5 Example of Yoke domain LSATI sweeps The 5 test can be exercised together with the application of an external magnetic field of arbitrary orientation to the write head This method generates a number of write head signatures that can be important for write head diagnostics such as enhanced coil yoke coupling sensitivity preferable domain orientation in the yoke and others Page 68 RIA User s Manual Integral Solutions Int l March 31 2010 20 3 Inductance Saturation in Magnetic Field LSATF test patent pending External magnetic field applied to the write head penetrates the yoke and causes multiple effects shifting domain walls rotation of magnetization and yoke saturation The LSATF measurement 15 different from the DC current saturation described in the previous section Yoke saturation caused by DC current 15 localized in the main pole area while in this test the entire head is exposed to a uniform magnetic field The LSATF test provides a higher level of details related to head saturation An example of LSATF transverse magnetic field sweep from 2500 to 2500 Oe is shown below 1 5 1 Inductance Saturation Field Test 1 25 1 00 0 75 0 50 Relative Inductance rH 0 25 2500 2000 1500 1000 0 500 1000 1500 2000 2500 Field Figure 6 Example of LSATF transverse field sweep range 2500 to 2500 Oe As seen inductance p
20. An example is shown below comparing two write heads from the same wafer 0 95 0 9 0 8 Angle 2 Normalized Relative Inductance 0 7 Sate Angle 1 0 65 80 60 40 20 0 20 40 60 80 Field Angle degrees Figure 17 Slider to slider YAT test variation example As seen the top trace YAT plot reveals double angle flare geometry which 15 less obvious for the bottom trace Application of YAT test for production control can become an important diagnostic tool for detection of defective flare samples with degraded performance Another application of the YAT test is related to finding preferable magnetization orientation of the flare region yoke anisotropy Different head designs may have complicated distribution of yoke anisotropy direction in the flare region Parallel to the ABS domain orientation shown in Figure 14 Is considered to be preferable for optimal head performance however more complicated transverse parallel configurations are possible as well as edge domains may be present In some cases magnetic properties of the flare region demonstrate strong angle dependent asymmetry indicating effective tilt of anisotropy An example of asymmetrical head 15 shown below Page 79 RIA User s Manual Integral Solutions Int l March 31 2010 anisotropic Normalized Relative Inductance lun 299
21. Depending on the write head design and yoke magnetic properties perpendicular and longitudinal Saturation modes generate specific LSATF type signatures Perpendicular mode is more natural for write heads after all this head is designed to generate strong perpendicular field component longitudinal saturation depend on yoke domain structure orientation tilt etc and dimensions Details of For example smaller cross track main pole dimensions result in a stronger demagnetization factor and smaller saturation for the same magnetic field magnitude compared to perpendicular direction Page 75 RIA User s Manual Integral Solutions Int l March 31 2010 For a given head design the difference of inductance for transverse and longitudinal magnetic field directions is stable However yoke defects such as variation of yoke dimensions cavities and domain structures result in changes of relative inductance levels The signature of defect types has to be established for different head designs In extreme cases the longitudinal field saturation is almost non existent An example of defective and normal YDT tested heads is shown above The magnetic field magnitude of 600 1000 Oe has a certain signature for a normal head such that both inductance values are very close at 800 Oe However the defective slider has a large inductance gap in this region Dynamic testing of this slider resulted in failed OW test and small write signal amplitude Page
22. Hd Grade Cycles TestTime Date Time 100 2387 Cycles 10 YHDFT 1 Yoke Hysteresis Domain Field Test chance rH Write Current m E ia 17 Field Magnitude 1500 A Field Angle deg 0 Figure 13 1 YHDFT Parameters 13 1 Setup Parameters 15 2 Cycles Average Write Current Field Magnitude Field Angle deg Results Inductance Pos rH Inductance Neg rH The number of times to toggle the field one cycle is set positive field and then set negative field This is how many measurements to take an average from at each cycle and field Each point on the plot will represent an average of several measurements The write current to be applied during the test Default value is OmA Note that the head may start to heat up with high enough current The heating process is somewhat slow and as a result this may be interpreted as a change due to field To avoid this use preconditioning parameters to preset current and delay and allow the head to reach its operating temperature The magnitude of the field to apply in each cycle This value must be positive The angle of the field to be applied during the test 0 degrees 15 considered Transverse 90 degrees is considered Longitudinal counter clockwise if looking at the magnet fro
23. Isotropic 40 30 20 10 0 10 20 30 40 Field Angle degrees Figure 18 YAT test comparison for isotropic and anisotropic flare region The red trace anisotropic head demonstrates considerable tilt of inductance measurements for positive field angles while the isotropic slider is symmetrical for both positive and negative field angles This result demonstrates that the effective magnetization of the flare region is tilted relative to the ABS This tilt causes write head asymmetry resulting in different field strength amplitude pulse width for transitions of opposite polarity Page 80 RIA User s Manual Integral Solutions Int l March 31 2010 20 7 Magnetic Memory Test patent pending Some write heads demonstrate considerable hysteretic effects caused by yoke domains lock up In some cases the hysteretic effect is caused by coupled multi layer structures in the pole flare regions Excessive hysteresis degrades head performance The MMT test checks the effect of head memory by sweeping the magnetic field or DC current in two opposite directions and reporting the difference of two inductance measurements An example of this test is shown below MIMT 1 Magnetic Memory Test 1 12 30 25 12 30 25 D elta haed17 ie 12 30 25 1 50 1 28 1 00 Relative Inductance rH 0 75 0 1 0 0 Delta Inductance K AME TEN LDU AL 5
24. YDT Parameters The field can be negative positive and zero The sweep pattern can be set by specifying from to and increment or by setting discrete values The sweep pattern can go from negative to positive or back the increment can stay positive 9 1 Setup Parameters Average This is how many measurements to take at each field Write Current mA The write current to be applied during the test Note that the head may start to heat up with high enough current The heating process 1s somewhat slow and as a result this may be interpreted as a change due to field To avoid this use preconditioning parameters to preset current and delay and allow the head to reach its operating temperature Field The sweep parameters for the test The From can be positive From To and negative or zero and so is To parameter Increment parameter Increment cannot be set to 0Oe Discrete If this option is turned ON then the From To and Inc are ignored and the semicolon separated values from the adjacent textbox are used For example 2000 2500 0 100 200 300 400 500 Avoid using the same field twice The software will allow it and the data generated will be valid but the plot may have extra lines in it 9 2 Results T Inductance rH Relative Inductance statistics measured while running transverse field sweep The rH in raw data is the relative inductance at each transverse field Each data point is the delta between the inductance measured and
25. then one value will be measured at 30 degrees and another at 30degrees Saturation Field This is the field magnitude to be used in the test Oe 10 2 Results Pos Tilt rH Relative Inductance value at positive field angle which should be similar to nH units This point is a difference between the inductance measured at the positive field angle and the LSATOffset parameter measured with RIA 2008 Setup parameters Neg Tilt rH Relative Inductance value at negative field angle which should be similar to nH units This point is a delta between the inductance measured at the negative field angle and the LSATOffset parameter measured with RIA 2008 Setup parameters Delta Tilt rH The difference between Pos Tilt rH and Neg Tilt rH Page 42 RIA User s Manual Integral Solutions Int l March 31 2010 10 3 Example Printout TMFT 1 Tilted Magnetic Field Test Grade Time Test Date Time 0178 1200185246 n TMFT 1 Tilted Magnetic Field Test Wite Current mA 0 re Saturation Field 000 Pos 6 52 16 PM Neg amp 6 52 16 PM Field Angle deg 45 Frequency MHz 00 5000 Pre Conditioning Results Parameters Grades Pos Tilt rH 0 124 0 124 0 124 0 0 Tilt rH 0 153 0 153 0 153 Delta Tilt rH 0 029 0 029 0 029 L D m 17 a zm na Frequency Mhz Clear Results Plat
26. 76 RIA User s Manual Integral Solutions Int l March 31 2010 20 6 YAT Yoke Anisotropy Test patent pending This test is based on unique multidirectional magnetic field capability of the 151 RIA tester This test is described below Figure 14 Demonstration of YAT test principle multiple angle inductance measurement in external magnetic field The YAT test provides relative inductance measurements by sweeping the magnetic field angle where the magnitude of magnetic field is fixed This provides angle dependence of yoke saturation as the magnetization mode changes from transverse perpendicular to cross track longitudinal The YAT result depends on the magnitude of external magnetic field refer to the LSATF test description previously described If the magnitude is selected in the range which corresponds to the flare region saturation but is lower than the main pole saturation then the magnetic response of the flare region is highlighted in the test output Changes of flare region magnetization have strong dependence on the external magnetic field angle As the field angle coincides with the characteristic flare angle the saturation mode changes from transverse to cross track This change of saturation mode Is detected by the steep dependence of the inductance value A typical example of YAT test is shown below Page 77 RIA User s Manual Integral Solutions Int l March 31 2010 Y AT 1 Yoke Anisotropy Test hea
27. FIGURE 21 BIGURE A LA SETUP EON 28 FIGURE DBST Ea Guia e a a io abdo aea 30 FIGURE l SATEXSASIPITPu Xu nece ai 31 be ba EN aa E E a 32 FIGURE6 2 T SATEPEXAMBEE PRINTOUT Su unas ulna Qua 33 FIGURE 7 1 S ATE PARAMETER E Z yu am bawa tei eua Een 34 FIGURE 72 S LSA TF EXAMPLE PRINTOUT rai u u a u n ter o bene iN d 36 FIGURE 37 FIGURE 223 en 39 BIGURE 9 Y DIT PARAMETER Sorron T so s M UM LE 40 PIGURE9 2 YD T EXAMPLE e YE Tuve o E TE Ne 41 FIGURE JOSLEPMET PARAMETERS 152 e Htutle
28. It could be disabled by the operator or by Reliability driver The driver can disable heads if it does not detect one of the boards The channel must be enabled in the Tools gt Options menu General Data Logging Login Parameters Test Specific Logging Auto Clear Results Keyboard Shortcut ta Start Production Test Heads Cartrige Labels Grading Kep 1 Space Key 2 Mone E Oo Mo Hdi Normalization Normalize By Tester SN Failure Production Warning Paper ir kom s Figure 3 6 Head Selection Page 21 RIA User s Manual Integral Solutions Int l March 31 2010 3 3 Running Tests To run the test click START button Select the head that you would like to run the test on Select the test from the button toolbar or the test tree refer to Quasi97 manual for more information then click Run Test The test will run and show the results on its menu You can select a different test and click Run Test again The required condition to run a test is that the bias is turned on button is pressed Quasi97 4 6 12 SETUP C Documents setupszxBar G3 troubleshoot mds gt LOG lt C Documents LOGS aa File View System Tools Calibrate Add Ins Diagnostics Help E Production Sweep Test 1 R Sampling Test 1
29. Original Setting b Add Parameter Remove Parameter Formula for m Formula for b Enable ReCalc Min Del l ee LSATF 1 LSAT Offset Base Variables Add here variable definition for variables that are used in formulas for m and b Add Variable Remove Variable n a LSAT 1 InductanceiH vg Figure 3 9 Adaptive Parameters Many standard Quasi97 tests will show Write Current Write Enable or Write DC mS and so on These writer related stress options and parameters are not used For all RIA measurements writer is disconnected from the QST 2002 and connected to the RIA module Writer resistance can be measured only through the Writer_Res test available in RIA 2008 software Page 23 RIA User s Manual Integral Solutions Int l March 31 2010 3 5 RIA 2008 Custom Stress RIA 2008 module also adds a few stress options that can be used to control the quad pole magnet and the writer during any test These stress options allow to enabling write current output setting write current setting field angle setting fixed field on one of the axis QPS Spliter Static Field Je 50 OPS 5plitter Static Field Y Pole Append Item OPS Splitter Field Angle Y 27 HA 2008 Bras Value 20 Remove Item Figure 3 10 RIA 2008 Custom Stress Field Control Field Angle XY XZ T
30. PATENT PENDING 92 APPENDI n 44 3 RIA User s Manual Integral Solutions Int l March 31 2010 21 APPENDIX B RIA EAQ u u R Qu A KE E Sec 85 22 APPENDIX C GEN3 PROBE CARD RIA COMPATIBILITY 89 25 LIMITED 55 u s 90 4 RIA User s Manual Integral Solutions Int l March 31 2010 Figures FIGURES Qa Su S FIGURE 122 COMPLETE SYSTEM estie a FIGURE 2 1 RIA SYSTEM CONNECTIONS a rS 12 FIGURE 3 1 RIA CONEIGURATION C EIU VS CH I t 19 FIGURE 3 22 SYSTEM MENU SELECTION au kai aspa 20 ADD INS SELECTED MODULES ha kanaa 20 FIGURE 3 4 INSTALLING AN itia eer eH ebd o rro EE IR
31. RIA is used on Blazer refer to this manual on how to set it up Page 7 RIA User s Manual Integral Solutions Int l March 31 2010 2 Installation 2 1 Requirements LISVAC 9 50 60Hz Single Phase 11 5A peak current 7A RMS e The tester can only run on Windows XP This is installed on the PC but if the PC 1s provided by the customer this requirement must be taken care of RIA is powered through an external power supply included while QPS splitter option uses only power provided through USB QMS 1050B also requires separate power Complete system uses 5AC outlets computer monitor QPS 1050 QMS 1050B RIA 2008 and 5USB ports on the computer keyboard mouse QST 2002 RIA 2008 QPS Splitter RIA 2008 is considered an add on QST 2002 and other hardware that this option will be installed with may have additional requirements Refer to the documentation provided with that equipment for more information The system is designed to be assembled on a desk Nominal dimensions 0517 2002 with quad pole magnet HGA Version 20 L x 10 W x 13 H QPS 1050 QMS 1050B 17 L x 16 W x 6 H RIA 2008 13 L x 8 W x 4 H QPS Splitter 6 L x 6 W x 2 5 H Page 8 RIA User s Manual Integral Solutions Int l March 31 2010 The magnet does not require cooling The QPS 1050 QMS 1050B and QST 2002 have slots on the bottom for air intake which should not be blocked RIA and QPS Splitte
32. RIA system and the write head under test The HSA preamplifier chip is physically placed within the pathway of the head so there is no direct connection available This limits RIA functionality to Wafer Bar Slider or level testing Q Can install the RIA system to my existing 151 QST 2002 HGA System Yes The version of the RIA system requires the Quadrupole Magnet and RIA specific HGA tooling but these components can be purchased as an add on kit to be installed by the customer onto any USB style QST 2002 System in the field To install the RIA system the QST 2002 System must already be equipped with the Gen2 2xHGA Base and Board Assembly which can be purchased separately know the RI A system works with the new ISI BlazerX6 Bar system s the RIA system compatible with my existing ISI BlazerX5 Bar System No The Bar version of the RIA system requires the BlazerX6 tester platform The BlazerX6 platform can be user converted between standard Gen3 Bar Testing or Quadrupole Magnet bar testing The Bar version of the RIA system can be user installed but requires both the BlazerX6 platform and the Quadrupole Magnet configuration Q What additional RIA test capability is ISI working on RIA write head testing is a new area of research and many aspects of the inductance measurements are still under investigation The ISI research team is pioneering advanced write head inductance characterization researc
33. Saturation I Bias Test The test sweeps write current hence the I in the name and measures inductance at each write current value Before displaying the results the test subtracts the LSATOffset from each data point which is inductance measured with RIA 2008 Setup parameters 5 1 Inductance Saturation I Bias Test imi Hd Grade Test Time Time Part IDC 1488 LSATII 1 7 20051847 8 ib d WU r hl A 1 1 CATI d Tie 30 nci o0 47 EF Field Graph LSATI 1 Inductance Saturation I Bias Test Field Angle deg 0 i 5 47 58 DC Write Current Sweep 0 405 From 50 50 Inc 1 Discrete Critical value s 50 0 400 Figure 6 1 LSATI Parameters 0 395 0 390 Pre Conditioning Write current can be negative positive and zero The sweep pattern be set by specifying from to and increment or by setting discrete values The sweep pattern go from negative to positive or back The test can extract the write current where the inductance value reaches certain value This is called critical value and the threshold or thresholds are user defined For example the test can return the write current where inductance 15 50 To do this the test will find the maximum and minimum inductances measured during the test scale the differenc
34. defective Products in the manner and for the period provided above Manufacturer shall not have any other obligation with respect to the Products or any part thereof whether based on contract tort strict liability or otherwise Under no circumstances whether based on this Limited Warranty or otherwise shall Manufacturer be liable for incidental special or consequential damages Other Statements Manufacturer s employees or representatives ORAL OR OTHER WRITTEN STATEMENTS DO NOT CONSTITUTE WARRANTIES shall not be relied upon by Buyer and are not a part of the contract for sale or this limited warranty Entire Obligation This Limited Warranty states the entire obligation of Manufacturer with respect to the Products If any part of this Limited Warranty is determined to be void or illegal the remainder shall remain in full force and effect Page 90
35. head13 2 36 27 s Delta head13 2 36 27 PM 0 800 0 775 0 750 a AU HH 0 10 20 30 40 60 70 80 90 100 Figure 21 Example of YHDIT test for randomly switching domain the write head Page 83 Integral Solutions Int l March 31 2010 RIA User s Manual Integral Solutions Int l March 31 2010 20 9 Appendix While every effort has been made to verify the accuracy of the information contained in this document this document may contain technical as well as typographical errors This document contains descriptions of products and tests that will evolve over time Changes and additional information will be incorporated into new editions of this document over time The material discussed in this document 15 considered Confidential Information of Integral Solutions International For more information on this material please contact Integral Solutions Int l 3000 Olcott Street Santa Clara 95054 Ph 408 653 0300 Fax 408 653 0300 Email Sales us isi com Web www us isi com Page 84 RIA User s Manual Integral Solutions Int l March 31 2010 21 Appendix RIA FAQ RIA FAQ Integral Solutions nternational Revision 10 28 2008 Q What ts RI A RIA stands for Relative Inductance Analyzer This is a new device designed by Integral Solutions International 151 for static write head testing and characterization without need of
36. in the transverse field orientation 8 Note the measurement on the gaussmeter A 9 Set the XY Angle to 180 degrees 10 Click Set Field and Angle 11 Note the measurement on the gaussmeter B 12 Calculate abs A abs B 2 and put the result into the field splitter Diagnostics menu gt Magnet Gain 13 Insert the gaussmeter probe in the longitudinal orientation 14 Set XY Angle to 90 degrees 15 Click Set Field and Angle 16 Note the readout on the gaussmeter C 17 Set XY Angle to 90 degrees 18 Click Set Field and Angle 19 Note the measurement on the gaussmeter D 20 Calculate abs A abs B 2 and put the result into the field splitter Diagnostics menu gt Magnet2 Gain 21 Click Write EEPROM in the field Splitter Diagnostics Menu 22 Restart the software 4 Field Control Diagnostics Main Board EEPROM BoardID A Board Rev A 4 BoadSN 4 2 ADC Steps 13 4 2 M esistance o Magnet2 Resistance 0 Magnets Resistance D Magnet G ain 38 egrets Gem o H Field Min 00 0 3 25 4 ADEMn 5 4 ADCGan Feature Vector 0 1 Magnet Saturation 4 Page 58 8T Pre Diagne Sim St Integral Solutions Int l March 31 2010 RIA User s Manual Integral Solutions Int l March 31 2010 17 3
37. may have extra lines in it Critical Value s Semicolon separated critical values The values can be numeric or a number followed by the symbol The difference is explain the introduction for this test Page 32 RIA User s Manual Rescale Graph rH 6 2 Results Inductance rH rH Slope Critical Bias lt gt Integral Solutions Int l March 31 2010 An option scale all results considering minimum inductance measured during the test as 0 and maximum as 1 This option allows to user to choose whether to plot the Slope or the Inductance This has no effect on the statistical results or Data Relative Inductance value which should be similar to nH This 15 the statistical result Ave Max Min etc from the rH in raw data The rH raw data 15 the relative inductance at each write current Each data point is the delta between the inductance measured and the LSATOffset parameter The relative inductance slope This 1s the statistical results from RH slope at each write current For each critical value the test will add a Critical Bias lt gt result For example the first critical value will be Critical Bias 1 The returned result will be in mA The lt gt does not depend on the critical value parameter but on the placement in the string For example for critical values 0 5 20 Critical Bias 1 is the write current where rH 0 5 and Critical Bias 2 is the write current wh
38. on the tester through the USB interface and serial port interface Bar Wafer Level The option is also available for Bar configuration on high frequency FMR option or low frequency probe card When using RIA with 2xBar Gen3 LF standard probe cards the capacitors C38 C39 C42 C43 C46 C47 C50 C51 will need to be removed This will disable the feature Clamp During Write On wafer LF probe card FAB 114730 capacitors C31 C50 C42 C43 should be removed For RIA usage the probe card should only use 2pt probing for WR connection Page 6 RIA User s Manual Integral Solutions Int l March 31 2010 11 Related Documentation This manual concentrates on the RIA option and the tests it introduces It can be used as a reference to look up the test algorithms meaning of test parameters and test results In addition to this the following literature is recommended Quasi97 Software User s Manual QST External Modules User s Manual RIA Measurements RIA FAQ Configuring BlazerX6 Options BlazerX6 User s Manual Supplement Contains detailed description of all menus in Quasi97 software along with procedures on how to set up test parameters log data and run the QST in production and engineering modes Description of additional tests provided with the QST and Quasi97 software A comprehensive guide on how to interpret results from various tests See Appendix A Common questions and answers about RIA system If
39. parameters will generate Angle Width 2 Angle Width 3 and so on results This results cannot be displayed on the plot 12 3 Example Printout YAT Sweep 1 YAT Bias Sweep Duk 0 0 Grade Cycles Test Time Test Dae Pai c Average 7 7 NAA YAT Sweep 1 YAT Bias Sweep I o m 1 m 25 m D x Field Magnitude 500 Field Angle Sweep From 80 Discrete fF DC Write Current Sweep From Inc Discrete Measure Angle Width 27 50 Fre Conditioning Results Parameters Grades Fat tical Field Angle 0 2 Em Angle width 2 HSE Field Angle Clear Flot Reset Temporary oom Show All Curves Chart Scale Figure 12 2 YAT Sweep Example Printout Page 47 RIA User s Manual inductance The test reports writer inductance at positive field negative field and the difference between them Fixed Integral Solutions Int l March 31 2010 13 YHDFT Yoke Hysteresis Domain Field Test The YHDFT applies positive and negative fields for a specified number of cycles and monitors writer write current value can be applied during this test User can also specify field angle and the number of measurements to take an average from in each cycle fae YHDFT 1 Yoke Hysteresis Domain Field Test
40. resistance If write current value is set to 0 then the write resistance result will be invalid Preconditioning This option allows user to define more complex stress and use that Only instead of Saturation field and Write Current parameters If this option is enabled the preconditioning will run first then the test will measure inductance using specified number of iterations then the test will restore field and write current parameters to whatever it was before the test Page 30 RIA User s Manual 5 2 Results Inductance rH 2008 Setup parameters 53 Example Printout SAT 1 Inductance Saturation Test Hd Grade Cycles TestTime Time gt Pat a R HdO N 055 LSAT I 1 12 200 15 18 07 I m 5 LSAT 1 Inductance Saturation Test 3 13 07 PM 0 09200 0 09175 0 09150 0 09125 0 09100 0 09075 Clear Results Plot Reset Temporary Zoom Show All Curves Chart Scale Integral Solutions Int l March 31 2010 The change in inductance from the value measured in with RIA Iterations f 00 Preconditioning only Em Saturation Field 2000 Write Current mA 20 Pre Conditioning Results Parameters Grades Inductance rH 0 091 0 002 Figure 5 2 LSAT Example Page 31 RIA User s Manual Integral Solutions Int l March 31 2010 LSATI Inductance Saturation I Bias Test The LSATI is Inductance
41. short time and then go off before the test is over Change the Field Angle parameter in LSATF test to 90 degrees and run the test Now the Active LED on the QMS 1050B should turn on and off Mount a real head on the HGA cartridge Run Transverse Test with default parameters check amplitude and resistance reading Run SMAN test check that the average noise amplitude 1s higher than 30uV The actual noise level will be higher and will depend on the head If the noise is lower then some connection is missing In Writer Resistance test set the current to 40mA and run the test The test should show correct writer resistance Once this checklist is complete the tester is operational and 15 ready for use If there are any problem review the connections or contact ISI support Page 13 RIA User s Manual Integral Solutions Int l March 31 2010 2 6 Installing RIA Upgrade If RIA upgrade was ordered then user will have to install additional components before the system can be used This is not required is the complete RIA system was ordered 1 Remove the old magnet from QST 2002 baseplate by removing the 4 screws on each side of the magnet 2 Put on new magnet 3 The quad pole magnet is mounted by 4 screws 2 on each side Use the outside holes for this To install the magnet insert one pair of screws first then shift the magnet to the back of the tester and install the second pair Use the short shoulder wre
42. the LSATOffset parameter Page 40 RIA User s Manual Integral Solutions Int l March 31 2010 L Inductance rH Relative Inductance statistics measured while running longitudinal field sweep rH raw data 15 the relative inductance at each longitudinal field Each data point is the delta between the inductance measured and the LSATOffset parameter Delta Inductance At each raw data point the delta between T Inductance and L rH Inductance is calculated and added as a third column delta inductance The statistical results from delta inductance are added as Delta Inductance rH result Hysteresis Hysteresis is the area between transverse and longitudinal curves calculated using Riemann sum method The units are rH Oe 9 3 Example Printout YDT 1 Yoke Defect Test Lus ese Cycles Te time res me c WA 23 27 m YDT 1 Yoke Detect Test Write Current m 0 T amp 6 51 45 PM L 6 57 45 Field Sweep From 2500 Inc Discrete Pre Conditioning Results Parameters Grades Pat ku ke LES Induc 0278 44 0 Ti 9 3 1 D m D a m Delta Inductance Cyd Clear Results Plot Reset Temporary Zoom Show All Curves Chart Scale Figure 9 2 YDT Example Printout Page 41 RIA User s
43. the plot will represent an average of several measurements Write Current mA The write current to be applied during the test Default value is 50mA This value must be positive Field Magnitude The magnitude of the field to apply in each cycle Default value is 0 Oe Field Angle deg The angle of the field to be applied during the test 0 degrees 15 considered Transverse 90 degrees is considered Longitudinal counter clockwise if looking at the magnet from the tooling side 14 2 Results Inductance Pos Relative Inductance value at positive write current This 15 the Statistical result Ave Max Min etc from the rH in raw data Each data point is the delta between the inductance measured and the LSATOffset parameter This is plotted in yellow color Inductance Neg rH Relative Inductance value at negative write current This is statistical result Ave Max Min etc from the rH in raw data Each data point is the delta between the inductance measured and the LSATOffset parameter This is plotted in blue color Inductance Delta The difference between inductance value measured at positive write rH current and negative write current This 15 also plotted in red color Hysteresis The area between the positive and negative inductance curves Page 50 RIA User s Manual Integral Solutions Int l March 31 2010 14 3 Example Printout ER YHDIT 1 Yoke Hysteresis Domain I Bias Test Made Lees Test Tine
44. to LSATOffset calculation extracted from LSATOffset Write Current mA The write current to be applied during the test Note that the head may start to heat up with high enough current The heating process 1s somewhat slow and as a result this may be interpreted as a change due to field To avoid this use preconditioning parameters to preset current and delay and allow the head to reach its operating temperature Field Angle deg The angle of the field to be applied during the test degrees 15 considered Transverse 90 degrees is considered Longitudinal counter clockwise if looking at the magnet from the tooling side Field The sweep parameters for the test The From can be positive From To and negative or zero and so is To parameter Increment parameter can Increment not be set to Page 34 RIA User s Manual Discrete Critical Value s Rescale Graph rH 7 2 Results Inductance rH rH Slope Critical Field lt gt Integral Solutions Int l March 31 2010 If this option is turned ON then the From To and Inc are ignored and the semicolon separated values from the adjacent textbox are used For example 2000 2500 0 100 200 300 400 500 Avoid using the same field twice The software will allow it and the data generated will be valid but the plot may have extra lines in it Semicolon separated critical values The values can be numeric or a number followed by the symbol The diffe
45. transfer curve resistance and noise Typically QST2002 writer 15 used for stressing the read write head QST2002 can enable DC or high frequency writing for any duration of time For RIA measurements the writer connection from the cartridge is diverted to the RIA module which 15 responsible for resistance and inductance measurements The RIA module is responsible for supplying the write current and measuring inductance of the writer This module is connected to the computer via USB port HGA configuration the module has a satellite daughter board that is installed on the 2xHGA Gen2 base In Bar Wafer configuration the RIA module connects to the probe card directly special configuration may be needed see Appendix The Quad pole magnet option includes the magnet the longitudinal coil power supply QMS 1050B and the QPS splitter module The option can change the field angle from 0 transverse to 90 longitudinal to 180 x degrees opposite transverse Figure 1 2 Complete System The option includes complete test suite of software including Quasi97 field proven test environment that includes logging grading production mode etc e RIA 2008 module contains the collection of tests for Quasi97 software e QPS Splitter module for manually setting and rotating the field e RIA module for manual inductance measurement The system 1s running Windows XP The computer communicates to all devices
46. 11 3 EXAMPLE PRINTOUT uwa m su SA ah 45 12 YAT SWEEP YOKE ANISOTROPY BIAS SWEEP TEST 46 ME NIL PER 46 222 ine 24 E 47 13 YHDFT YOKE HYSTERESIS DOMAIN FIELD TEST 48 13 1 SETUPTPABRAMETEDBS 2 ON oV doen 48 9 2 FIRES UIE TS uuu 48 19 32 EXAMPLE PRINTOUT E 49 14 YHDIT YOKE HYSTERESIS DOMAIN I BIAS TEST 50 Pdl SEIDPPARAMBEIBRS heil nn UNO ree 50 PEZ 41 AS Pm SSS S S S SA 50 EXAMPLE PRINTOUT aac M cal m 51 15 MMT MAGNETIC MEMORY TEST 52 IS SST P
47. 56 0 eiaa coute ete Siqa 54 FIGURE 1622 WRITER RES PRINTOUT oer eov vous a u Erbe ev dote vec os do aQ EET de aaa 55 FIGURE W 8 1 FS 12010 DIAGNOSTICS MENU Z ee qug var Ee eoru bd cuve eva INE UER SUE 61 PIGURE 1822 HATESEERECT CARTRIDGE dade ev aq Bas dou ds du aqa teca des eye asocia 61 FIGURE 18 3 QUAD POLE MAGNET CALIBRATION ADAPTOR a se rh es 62 FIGURE 18 4 GAUSSMETER PROBE rave Ede ee E et E E do Ux aee EE do Ev oa di doe d YA VEN EOM PENAS uw vo 62 Page 5 RIA User s Manual Integral Solutions Int l March 31 2010 1 Introduction The Relative Inductance Analyzer utilizes high resolution inductance measurement to characterize the write head statically The writer can be analyzed by applying programmable current magnetic field and magnetic field angle The principle of the RIA measurement suite 1s characterization of the magnetic part of write head inductance and changes of inductance while applying specific combinations of external multi directional magnetic fields and DC write currents system includes the RIA module 4 pole magnet and QST 2002 system The QST 2002 system performs standard measurements on the read head including
48. 9 2 31 26 fi N WV V J 4 b y My ANA AAN W 10 20 40 60 70 80 90 100 Cycle YHDIT 1 Yoke Hysteresis Domain I Bias Test _ 1 Pos head12 2 35 09 PM Neg head12 2 35 09 PM Delta head12 2 35 09 0 750 0 725 0 700 Relative Inductance rH 0 675 0 05 0 00 Delta Inductance 0 05 0 10 20 40 60 70 80 90 100 Figure 20 Example of YHDIT test for 100 consecutive inductance measurement cycles with 45 mA write current Top graph normal head bottom strong hysteresis sample Two traces are shown in each graph window bottom trace inductance difference for two opposite polarities of DC current the above example inductance was measured for 100 consecutive cycles of applying 45 and 45 mA DC current The top graph shows normal write head with moderate 10 15 pH inductance variations Page 82 RIA User s Manual after current stress The bottom graph is an example of hysteretic head inductance variation on the order of 0 1 nH The next figure illustrates random domain lock ups in some sliders This head switches between noisy and quite states during the current stress exercise Relative Inductance rH Delta Inductance YHDIT 1 Yoke Hysteresis Domain I Bias Test j Pos head13 2 36 27 Neg
49. AR AIMEE RS verde uy y uyu ai haha Kon 52 TPE DEP NM MO uuu aa 53 Ho EXAMPEBTDPBINTODTZ u aun n Q Qasa pe kusa h 53 16 WRITER RES WRITER RESISTANCE TEST 54 uuu Dua u a kuman D uy Pabalu um anise 54 Ti DDOS Os ulna u Dtm na CM f ust LM LI M IM MM 54 16 3 m ua w s E a 55 ad Ba Socr d E E um uu ss Sum 56 Ty TANCE t uma M 56 TI M ei 57 LES 25523 59 ES Sau als u au sQ 60 ISl OPS SPEIER OPTION luu u aso te basCusded bbs 60 16 2 ISI2010 DIAGNOSTICS
50. E 1 Saturation Field Test 6 57 09 2500 2000 1500 1000 5 1000 1500 2000 2500 Field ear Reset Temporary oom Chart Scale Integral Solutions Int l March 31 2010 Average Rescale Write Current 0 Graph Field Angle dex 0 Field Sweep From 2500 2500 Inc Discrete Critical value s 50 Results Inductance rH 0 392 0 D 9 Slope Critical Field 1 1300 Figure 7 2 LSATF Example Printout Page 36 RIA User s Manual Integral Solutions Int l March 31 2010 8 CYCET Coil Yoke Coupling Efficiency Test The CYCET test is a combination of LSATF and LSATI tests The test sweeps transverse magnetic field and measures inductance at each field value Then the test determines the field where the inductance value reached Critical Value threshold Then the test sets that critical field and sweeps write current at that field according to user setup Before displaying the results the test subtracts the LSATOffset from each data point which 15 inductance measured with RIA 2008 Setup parameters a CYCET 1 Coil Yoke Coupling Efficiency Test 4 z ioj x Grade Cycles Time Tes Time Part ID 1 20 CYCET 1 1727200 18 26 Graph Field CYCET 1 Coil Yoke Coupling Efficiency Test Inc i B 51 25 PM 0 40 Discrete 4 F Fre Con
51. Effect Reset Default TRES is Operator ID Read Bias Hd 0 Taster IU B Read Bias Hd 1 B Default Field 01000 5 Write Curent m 25 0 Commens Write Frequency MHz 5 o Write Stop Positive x Maximum Limits Maximum Field Clamp Voltage 2 Maximum Read Bias 5 7 Figure 3 2 System Menu Selection The next step is to add RIA2008 Application to the setup file This will add a group of writer related tests to the test tree Add In Manager 4 Ir x pp Application ESDApp ppicaion MO Lifecycle application 1 LiqhtF ole_ Application ranster Application e 0O SideField Application Insert ltem Append Item ample Application FiaZ008 Application QPS Solitter 4oplication Remove Item Figure 3 3 Add Ins gt Selected Modules The Total of Heads should be set to 2 in the system menu Also the maximum field might need to be changed to about 3000 Oe The actual maximum field that the system can go to depends on the magnet To determine that value go to Calibration menu and check field gain FieldGain 10 is the maximum field in Oe that the system support Page 20 RIA User s Manual In
52. Full Typical installation of Quasi97 is required for the tester to work In addition to Quasi97 the RIA 2008 module should be installed The RIA 2008 software requires runtime license refer to runtime license section for more details To start the software double click on Quasi97 icon on the desktop Next step is to select a setup file from the list click Select Setup button If there is no setup refer to Quasi97 User s manual on how to create or add a setup to the list After opening a setup file check the system menu In the setup file the tester configuration should be set to 2x BAR Gen2 2xHGA Gen2 If the setup file is adapted from other tester configuration then change tester configuration to 2x HGA Gen2 System Configuration Menu System Parameters Preamp Control Timing Stress Preamp Auto Detect Tester MR Head Tester Configuration MR Head Type GMA Spin Vave MR i Channel Single Stripe CH 1 ume Lead Resistance Ohm 0 Preamp Chip 1561984 N K Beta 00032 Field Polarity Method ar Cartridge N Head Preheat Time 0 Field Polarity Near Cartiridge Facing Down v Field Polarity Far Cartridge FacingDOWN 0 3 Fs eame Rn Fons Startup Preheat Time Resistance Amplitude Range ne 2 Device Driver Name Setup Total Of Heads System in
53. LSAT INDUCTANCE SATURATION TEST 30 5 1 SETUP PARA METE UR cuu Le 30 52 PLSI DI TO 31 5 3 EXAMPER PRINTO a oT eR SEN AT 31 6 LSATI INDUCTANCE SATURATION I BIAS TES 32 6 1 LE P AJO ya 32 6 2 04 is tM es 33 6 3 AKII uuu uuu e dL 33 7 LSATF INDUCTANCE SATURATION FIELD TEST 34 7 1 SETUP PAR AMIE TERS etos fof Luce 34 7 2 RESULTS 35 7 3 36 8 CYCET COUPLING EFFICIENCY TEST 37 8 1
54. License The RIA 2008 software needs a runtime license to operate The license is stored in the RIA 2008 lic file located in the c program files integral solutions int RIA 2008 The license is locked to the serial number of the RIA controller module and RIA 2008 software version So each RIA system will have its own lic file and some software upgrades will also require purchasing a new run time license Once the runtime license is purchased it does not expire for that particular RIA 2008 version and RIA system r RIA2008 File Edit View Favorites Tools Help C E gt Search Folders Es gt Address C Program Filesintegral Solutions Int l RI42008 T File Folder 1 14 3 028 KB Application Extension 1 14 2 1KB LIC File 1 14 s RI4 2008 Users Manual pdf 1 552 KB PDF File 1 14 Figure 3 11 RIA 2008 Runtime License To purchase the run time license you need to contact ISI sales and provide the application name RIA 2008 the version of the application for example 1 1 8 and the serial number of the RIA module The version of the application can found in the Windows Control panel add remove modules RIA 2008 Another way is to right click 2008 4 file then click properties and check the version number The serial number of the RIA module is outside of the box next to the power connector The serial number can also be found whe
55. Magnet Alignment The magnet position will depend on the type of cartridge installed UP or DOWN The height of the magnet is also adjustable The following procedure shows how to adjust the magnet 1 The magnet is held by 4 screws at the base Loosen all 4 screws as shown on the picture 2 Move the magnet such that the head in the tooling is in the midpoint between the 4 poles 3 Tighten the screws One of the screws may be hard to access use a shorter wrench to access it 4 Onthe back of the magnet loosen the 4 screws 5 Use the Vertical alignment screwn V to move the magnet UP and DOWN 6 Use to determine best height of the magnet 7 After the magnet alignment is done secure the 4 screws on the back of the magnet Page 59 RIA User s Manual Integral Solutions Int l March 31 2010 18 Tools 18 1 QPS Splitter Option Refer to External Tests manual for more information on this option Page 60 RIA User s Manual Integral Solutions Int l March 31 2010 18 2 1512010 Diagnostics The RIA Controller module diagnostics can be engaged in standalone mode by using ISI2010 Diagnostics shortcut This will bring up a menu where RIA eeproms and control register can be found Navigate to 5 2010 gt 2 16 to open its diagnostics menu 1512010 Diagnostics Modules 0 USB POWER Basic Communication Burst Mode Count 1 White Address W
56. Manual Integral Solutions Int l March 31 2010 10 TMFT Tilted Magnetic Field Test The TMFT measures inductance at two user specified field angles The write current magnetic field and the field angle can be specified in the test The plot shows two points positive and negative for inductance measurement at positive angle and at negative angle TMFT 1 Tilted Magnetic Field Test Hd Grade Cycles Test Time Date Time Pat D 62 1 0178 TMFT 1 Averages Current m 8 1 Tilted Magnetic Field Test Fa aturation Field 1000 Fos 68 52 16 Meg amp 6 52 16 PM Field Angle deg 45 Frequency 100 To 15000 0 450 Fre Conditioning 0445 Figure 10 1 TMFT Parameters 2TH The frequency sweep is not supported by the RIA system and these parameters cannot be enabled 10 1 Setup Parameters Average This is how many measurements to take at each field Note that this parameter does not apply to LSATOffset calculation extracted from LSATOffset Write Current mA The write current to be applied during the test Field Angle deg The angle of the field to be applied during the test degrees 15 considered Transverse 90 degrees is considered Longitudinal counter clockwise if looking at the magnet from the tooling side The test will apply field angle So if the value is 30
57. agnet 1 Change Magnet to 100 2 Change Magnet Gain2 to 100 3 Go to Field Control main menu and enable Set Field Locally checkbox Set XY angle to transverse field Set Magnitude to 100 Click Set Angle and Field button 4 5 Field Control Diagnostics Main Board EEPROM Y QST Present Nam Read FLDCTRL 1 Diagnostics Single Write Magnet Resistance Magnet2 Resistance 0 Magnet3 Resistance Read Registers Magnet Gain Magnet2 Gain Magnet3 Gain Field V Max 10 Field V Min ADC 2 5 ADC 2R Field Control Diagnostics Magnet Angles xY Angle 2 j 4 Settling SetField Locally Static Field Overrides Angle O D Angle Controlled GST 0 10 Inverted Get To 100 Output 3 Angle Controlled GST DE 07107 Inverted 451 e 072107 Inverted Set To Stop All Output RESET ALL Page 57 Current Field Splitt QST Outp QST Gain X Magnitu Y Magnitu Z Magnitu xY Angle Angle q n il M a q n il YZ Magn Start Se RIA User s Manual 7 Insert the special gaussmeter tool into the magnet
58. ameter does not apply to LSATOffset calculation extracted from LSATOffset Write Current mA The write current to be applied during the test Field Angle deg The angle of the field to be applied during the test 0 degrees is considered Transverse 90 degrees is considered Longitudinal counter clockwise if looking at the magnet from the tooling side Field Oe The field magnitude to be used in the test Sweep The sweep parameters for the test The From can be positive From To and negative or zero and so is To parameter Increment parameter Increment cannot be set to 0 Depending on the sweep option chosen then units will be in Oe degrees or mA Discrete If this option 15 turned ON then the From To and Inc are ignored and the semicolon separated values from the adjacent textbox are used For example 2000 2500 0 100 200 300 400 500 Graph rH This option allows to user to choose whether to plot the Slope or the Inductance This has no effect on the statistical results or Data Page 52 RIA User s Manual 15 2 Results Inductance Pos rH Inductance Neg rH Inductance Delta rH Hysteresis Integral Solutions Int l March 31 2010 Relative Inductance value measured in forward sweep This is the statistical result Ave Max Min etc from the rH raw data Each data point is the delta between the inductance measured and the LSATOffset parameter This 15 plotted in medium thickness solid line Relati
59. cient bottom sliders of the same design The DC current required to achieve a 50 decrease of inductance varies from 40 mA top to 47 mA bottom For smaller DC currents the change of inductance 15 small and noisy This is related to multi layer magnetic structures in the pole flare regions and random changes of domain configuration For larger currents inductance roll off is more pronounced Highly efficient write head saturates faster For example the top graph shows significant drop of inductance for 1240 mA while the bottom graph requires approximately 47 5 mA for the same change of inductance This indicates that the head shown Page 67 Integral Solutions Int l RIA User s Manual March 31 2010 on the top graph is more efficient it develops larger yoke flux for the same amount of write current and therefore is capable of generating stronger field Some heads have significant yoke hysteresis resulting in non repeatable inductance measurements This is caused by domain lock up in the yoke An example of such domain problem is shown below multiple sweeps of write current from 60 to 60 mA result in non repeatable inductance values within the range between 40 and 20 mA Domain lock up problem can translate into non repeatable transition recording for a certain polarity and write current range and result in BER degradation Relative Inductance 0 6 60 40
60. crete Critical Value s 8 2 Results Inductance rH Critical Field lt gt Critical Bias lt gt Integral Solutions Int l March 31 2010 This option allows user to choose whether to plot the first stage of the test field sweep or the second stage write current sweep Note that this value is saved to the setup file so even though this has no effect on raw data and statistics it does have an impact on what kind of plot will be saved The sweep parameters for the test The From can be positive negative or zero and so is To parameter Increment parameter cannot be set to If this option is turned ON then the From To and Inc are ignored and the semicolon separated values from the adjacent textbox are used For example 2000 2500 0 100 200 300 400 500 Avoid using the same field twice The software will allow it and the data generated will be valid but the plot may have extra lines in it Semicolon separated critical values The values can be numeric or a number followed by the symbol The second stage of the test write current sweep will be done at the Critical Field 1 The sweep parameters for the test The From can be positive negative or zero and so is To parameter Increment parameter cannot set to OmA This controls the second stage of the test after the critical field value 15 determined If this option is turned ON then the From To and Inc are ignored and the semicolon s
61. cy Test Grade Test Time Test Time P IHd 2D41 1 1 7 2008 18 51 25 Graph vi Field 1 Coil Yoke Coupling Efficiency Test Field Sweep 51 25 PM From 2500 Inc 50 Discrete Critical value s Z 25 Fre Conditioning DC White Current Sweep From 0 50 Inc Discrete Critical value s i 90 Results Parameters Grades Res _ Relative Inductance rH 0 096 0 108 0 091 0 Critical Field 1 160 L m 17 a na Field Clear Results Flot Reset Temporary Zoom Show All Curves Chart Scale Figure 8 2 CYCET Example Printout Page 39 RIA User s Manual Integral Solutions Int l March 31 2010 9 YDT Yoke Defect Test The Yoke Defect Test is similar to LSATF test but takes two curves at Transverse and Longitudinal orientations The test also shows the delta between the two curves calculates statistics on the delta and shows it on the plot EE 2151 x Hd Grade Cycles Test Time Test Time PatlD 2573 YDI 1277200185145 Averages YDT 1 Yoke Defect Test write Current mA 0 6 51 45 PM L 6 54 45 PM 0 40 Field Sweep From E To 2500 Inc 0 35 Discrete 0 30 5 E 025 Pre Conditioning Figure 9 1
62. d the preconditioning will run first then the test will measure inductance using specified number of iterations then the test will restore field and write current parameters to whatever it was before the test Page 28 RIA User s Manual Integral Solutions Int l March 31 2010 4 2 Results The test generates Inductance rH result which is then used as LSATOffset in other test Inductance rH Inductance value which should be similar to nH Page 29 RIA User s Manual Integral Solutions Int l March 31 2010 5 LSAT Inductance Saturation Test LSAT simply presets field and write current and measures inductance of the head several times Then statistics are calculated from raw data and added to the results Each data point in this test is relative inductance value one compared to the inductance of the saturated writer For example RIA 2008 Setup defines 3000 Oe as the saturation field for inductance measurement LSATOffset If LSAT test measures at 1000 Oe field each data point in the LSAT test will be the difference in inductance value between 1000 field and 3000 field If LSAT test is set up to measure to 3000 then results will be centered around 0 rH This is because in our example the saturation value is also measured at 3000 Oe This test maybe useful for sweep test LETE Hd Grade Cycles Test Time Tes Dats Time fhao NA 0632 LATI area leraions 07
63. d a Critical Field Pos lt gt result For example the first critical value will be Critical Field Pos 1 The returned result will be in degrees 113 Example Printout FS YAT 1 Yoke Anisotropy Test Grade Cycles Test Time Test Date Time Bs 84 Averages 00 i 0 YAT 1 Yoke Anisotropy Test Write Current I I 5 2 o 2 6 52 35 PM Field Magnitude 500 Field Angle Sweep From 30 To 9 Inc 5 Discrete Critical value s 502 Results Relative Inductance H 0 312 358 20 Critical Field Pos 1 s Po To Critical Field Neg 1 3 0 Field Angle Figure 11 2 YAT Example Printout Page 45 RIA User s Manual Integral Solutions Int l March 31 2010 12 YAT Sweep Yoke Anisotropy Bias Sweep Test This is a implementation of YAT test which also sweeps write current At each field angle during the sweep the test will sweep through write currents At each write current the test measures the width of the waveform at a user defined threshold R YAT Sweep 1 YAT Bias Sweep E Grade Cycles Test Time Test Time 41 i 15708 1 1 7 2005 185333 Duos Graph rH 30 Field Magnitude pe 500 Field Angle Sweep From 90 30 Inc 5 Discrete DC Wri
64. d by the symbol The sweep parameters for the test The From can be positive negative or zero and so is To parameter Increment parameter cannot be set to 0mA Write current sweep occurs at each field angle If this option is turned ON then the From To and Inc are ignored and the semicolon separated values from the adjacent textbox are used For example 50 25 0 1 2 3 4 5 6 10 12 16 Page 46 RIA User s Manual 12 2 Graph rH 3D Angle Measure Angle Width Results Critical Field Angle Angle Width lt gt Integral Solutions Int l March 31 2010 User can select to plot the full set of data rH 3D vs field vs write current or Angle Width vs Write Current This 1s the inductance threshold which will be used to find two field angles positive and negative The field angle width result 15 the delta between positive and negative field angles More than 1 field angle width threshold can be specified which simply generate more results Angle Width 2 Angle Width 3 etc The first field angle width will be used to calculate Critical Field Angle result This is the difference between positive and negative angles in degrees where the threshold crossed measure angle width parameter This value will be calculated for each write current sweep and placed into raw data Then the statistics of Critical Field Angle result will be calculated The second and subsequent Measure Angle Width
65. d that some boards will not be detected during startup If the board not detected is a board you believe you have please contact ISI This can occur if the 4 pin writer cable is connected on the cartridge In this case the preamp chip will interfere with RIA measurements The 4 pin writer cable on the 2xHGA cartridge should not be connected when running RIA tests Page 63 RIA User s Manual Integral Solutions Int l March 31 2010 20 Appendix A RIA Measurements Introduction to RIA Measurements Integral Solutions nternational Revision 10 28 2008 ISI Confidential nformation 20 1 Perpendicular Write Head Structure A simplified sketch of perpendicular head is shown in Fig 1 Main pole I F g 1 f rj gt Trailing shield and return yoke M Disk rotation Figure 1 Perpendicular write head structure The Read sensor is located in the left part of this figure and the Write head is on the right The Write head can be represented as a coil wrapped around the magnetic yoke As write current is applied to the coil magnetic flux is induced in the yoke This flux propagates to the recording pole and generates perpendicular magnetic field at the pole surface adjacent to the magnetic media This field has perpendicular direction Modern write heads generate more than 10000 Oe 1 Tesla field at the ABS of the pole This field is sufficient to exceed co
66. d7 9 15 23 AM 1 8 1 7 TN 1 6 1 5 9 1 4 gt 5 1 3 1 2 1 1 75 25 0 25 75 Field Angle Figure 15 Typical YAT test result Magnetic magnitude is 300 Oe angle sweep from 80 to 80 degrees transverse field direction corresponds to 0 degrees As seen relative inductance changes are small for the range of angles from 30 to 30 degrees A steep jump of inductance occurs at 50 and 55 degrees The nominal flare angle design for this type of write head was 60 degrees changes of flare angles are observed on individual sliders and correspond to manufacturing variations The next figure illustrates YAT tests comparison for different head flare design angles ranging from 25 to 60 degrees As seen the typical flare angles are consistently reflected in YAT test result Narrow N N B ma 0 95 I m i ais 0 9 X 4 J N gt 0 85 gt 5 3 0 8 5 0 75 I N x 3 Medium P 7 i 7 E J 0 7 0 65 80 60 40 20 0 20 40 60 80 Field Angle degrees Figure 16 YAT test comparison for 3 different head flare angle designs Page 78 RIA User s Manual Integral Solutions Int l March 31 2010 YAT measurements of write heads reveal considerable variations of flare geometry angles flare asymmetry and double angle features
67. disable the feature Clamp During Write On wafer LF probe card FAB 114730 capacitors C31 C50 C42 C43 should be removed For RIA usage the probe card should only use 2pt probing for WR connection There are two modes of running the RIA on Blazer one using the normal test location with either the HF probe card or LF probe card and the second method is using the stress location or ESD bridge The first method 15 straight forward conventional probe card is used but instead of the preamp chip the RIA is connected to the writer probes The LF probe card set up requires a special writer intermediate board with SMC connectors while HF probe card already has SMC connector that can be used by RIA Although in the later case user must ensure that the HF probe card 15 aligned to writer pads and not the reader alignment is not automatic Figure 3 14 RIA on Blazer The second method requires installation of the second probe card just above the trays See Aligning Stress Probe card in BlazerX5 X6 user s manual for more details on how to set this up In this case reader testing is not compromised because standard 2 channel read write probe card can be used However the test set up is more complicated where the user has to align the stress probe card and in Quasi97 enable Alternative Test Site is mds LOG lt gt ie Add Ins Diagnostics Help Quasi Static Tests 1 Static Tests 1 EL Sweep Test 1 iH Produ Gene
68. ditioning Critical value s 255 0 35 DC write Current Sweep From 0 50 Inc 5 0 30 Discrete Critical value s 50 0 25 Results Data Parameters Grades stance rH Figure 8 1 CYCET Parameters The sweep pattern for the field can be set by specifying from to and increment or by setting discrete values The sweep pattern can go from negative to positive or back The test can extract the field where the inductance value reaches critical value The critical field value 15 set by user More than one critical value can be specified but they need to be separated by semicolon If the critical value number has sign next to it then the software will determine the value to look for first using min and max inductance If there is no percent sign then the software will look for the actual inductance value For example 0 5 would indicate 0 5rH to the software while 30 would indicate Lmin 0 3 Lmax Lmin If there is more than one critical value in the field sweep only the very first one in the list will be used to run the second stage of the test write current sweep However all critical values will be found by the test and added as results Critical Field lt gt The write current sweep will occur at the Critical Field 1 found by software Write current sweep pattern can also be set by through from to and increment or by setting discrete values The sweep pattern can go from negative to posit
69. e as 100 and will find the write current where inductance is closest to 50 More than one critical value can be specified but the need to be separated by semicolon If the critical value number has sign next to it then the software will determine the value to look for first using min and max inductance If there 15 no percent sign then the software will look for the actual inductance value For example 0 5 would indicate 0 5rH to the software while 30 would indicate Lmin 0 3 Lmax Lmin 6 1 Setup Parameters Average This is how many measurements to take at each write current Note that this parameter does not apply to LSATOffset calculation extracted from LSATOffset Field Oe The DC field to be applied during the whole test Field Angle deg The angle of the field to be applied during the test degrees 15 considered Transverse 90 degrees is considered Longitudinal counter clockwise if looking at the magnet from the tooling side Write Current The sweep parameters for the test The From can be positive From To and negative or zero and so is To parameter Increment parameter can Increment not be set to OmA Discrete If this option is turned ON then the From To and Inc are ignored and the semicolon separated values from the adjacent textbox are used For example 50 25 0 1 2 3 4 5 6 10 12 16 Avoid using the same write current twice The software will allow it and the data generated will be valid but the plot
70. e recording pole is too small 100 nm or less to be detected using an inductance method A rough analogy of inductance is object mass weight The typical scale of yoke trailing and return poles is comparable to multi story building while the recording pole itself is similar to a tiny TV antenna on the building s roof Measurement of this antenna weight vs the entire building is virtually impossible especially taking into account that total head inductance is about 1 nH or less While the pole signatures in RIA measurements are extremely small the issue of pole defect detection with RIA is still under investigation some cases such as strong pole corrosion certain Page 86 RIA User s Manual Integral Solutions Int l March 31 2010 inductance field saturation changes can be detected Similarly nose length variations often correlate with head saturation however a most plausible interpretation of these results is that the correlation 15 mainly caused by changes of domain configuration in the flare region dependent on the actual pole nose length Q Can RIA measurements characterize write head rise time and data rate performance No Write head rise time is related to frequency roll off of inductance which typically occurs in 1 3 GHz range This roll off can be measured with a wide bandwidth network analyzer and high frequency probes 151 RIA system is designed for a single 250 MHz frequency and 15 not capable of freque
71. eaks at 0 Oe and roll off is reasonably symmetrical for positive and negative field values This is not always the case as will be shown later A number of inductance kinks can be clearly seen in this figure The first kink drop of inductance occurs at approximately 150 Oe followed by gradual saturation up to 500 Oe and a flat shoulder between 500 900 Oe The first inductance kink corresponds to reconfiguration of the flare region magnetization mainly due to shift and rotation of flare domains Gradual saturation 15 explained by rotation of magnetization in the flare and lower main pole regions The flat shoulder region corresponds to the field range when the flare region is saturated while the massive main pole is not reversing its magnetization Some edge domain rotation occurs in this region followed by a sharp decrease of inductance in 950 1300 Oe field range This field range corresponds to main pole region saturation The typical LSATF plot described above varies for different head designs Location of kinks shape Slope and inductance level are design dependent and are unique for each particular head type The Page 69 RIA User s Manual Integral Solutions Int l March 31 2010 next graph demonstrates an LSATF plot for two different head designs having longer and shorter yoke length As seen the short yoke head has smaller inductance and different kink locations 2 Longer yoke Higher
72. easured during the test scale the difference as 10096 and will find the field where inductance was closest to 50 More than one critical value can be specified but they need to be separated by semicolon If the critical value number has sign next to it then the software will determine the value to look for first using min and max inductance If there is no percent sign then the software will look for the actual inductance value For example 0 5 would indicate 0 5rH to the software while 30 would indicate Lmin 0 3 Lmax Lmin 11 1 Setup Parameters Average This is how many measurements to take at each field Note that this parameter does not apply to LSATOffset calculation extracted from LSATOffset Write Current mA The write current to be applied during the test Note that the head may start to heat up with high enough current The heating process 15 somewhat slow and as a result this may be interpreted as a change due to field To avoid this use preconditioning parameters to preset current and delay and allow the head to reach its operating temperature Field Magnitude The magnitude of the field vector to be applied during the test Oe Field Angle Sweep The sweep parameters for the test The From can be positive negative or zero and so is To parameter Increment parameter cannot be set to 0Oe 0 degrees is considered Transverse 90 degrees 15 considered Longitudinal counter clockwise if looking at the magnet fr
73. el inductance Resistance and wafer level inductance testing allow the user to discriminate major electrical interconnect and coil defects such as defective electrically open or shorted writers Otherwise dynamic spinstand testing remains the only way to characterize write head performance RIA testing provides detailed information about magnetic properties of write heads A number of advanced RIA tests are based on inductance changes caused by DC write current and multi directional magnetic field This allows detailed characterization of yoke magnetic properties and defects permeability variations domain and stress induced anisotropy hysteresis magnetostriction and coil yoke interactions efficiency of head magnetic circuit Slider to slider variations of RIA measurements usually correlate to results of dynamic tests magnetic write width overwrite write asymmetry A unique feature of the ISI RIA system is multi directional magnetic field testing which allows characterization of yoke magnetic anisotropy and flare geometry and magnetic response All these features allow early bar level or perhaps wafer level production detection of write head defects Q Can recording pole defects be characterized using RIA testing A Recording pole defects such as corrosion nose length and pole width variations have strong impact on write head performance However RIA measurements mainly provide information about the yoke flare and write coil Th
74. eparated values from the adjacent textbox are used For example 50 25 0 1 2 3 4 5 6 10 12 16 Avoid using the same write current twice The software will allow it and the data generated will be valid but the plot may have extra lines in it Semicolon separated critical bias values The values can be numeric or a number followed by the symbol Relative Inductance value which should be similar to nH This is the statistical result Ave Max Min etc from the rH in raw data The rH in raw data 1s the relative inductance at each write current Each data point is the delta between the inductance measured and the LSATOffset parameter For each critical field value the test will add a Critical Field lt gt result For example the first critical value will be Critical Field 1 The returned result will be in Oe The lt gt does not depend on the critical value parameter but on the placement in the string For example for critical values 0 5 20 Critical Field 1 is the field current where rH 0 5 and Critical Field 2 is the magnetic field where rH 15 2096 of the range For each critical write current value the test will add a Critical Bias lt gt result For example the first critical value will be Critical Bias The returned result will be in mA Page 38 RIA User s Manual Integral Solutions Int l March 31 2010 9 3 Example Printout a CYCET 1 Coil Yoke Coupling Efficien
75. ercivity and to reverse magnetization of recording media transition recording Magnetic flux propagates to the media through the soft underlayer green layer to the return pole right region of write head A more detailed cross section structure of the typical perpendicular recording head is shown in the next figure The write coil is wrapped around the main pole main yoke a massive piece of magnetic material above the recording pole The main pole is usually recessed from the ABS n some designs the coil is wrapped around the upper horizontal layer of the yoke closing the gap between the trailing Page 64 RIA User s Manual Integral Solutions Int l March 31 2010 main and return poles In some head designs the trailing and return poles are not magnetically connected to the main pole floating poles Trailin g pole Recording shield Figure 2 Perpendicular write head cross section structure The trailing pole is connected to the trailing shield The trailing shield edge is adjacent to the recording pole with pole shield separation ranging from 30 to 200 nm The trailing shield closes part of the magnetic flux from the recording pole to the trailing pole As a result the effective field in the media 5 tilted from perpendicular direction which can be advantageous for media switching Approximate cross track geometry of the main pole coil and recording pole is shown in the figure below The transition between the
76. ere 20 of the range 6 3 Example Printout LSATI 1 Inductance Saturation I Bias Test Grade Cycles Test Time Tes N X m a 2 2 s 1777200 18 47 58 Average Rescale 1 10 47 Field 0 Graph gt LSATI 1 Inductance Saturation I Bias Test Field Angle deg 0 6 47 58 PM Write Current Sweep EH From 50 To 50 Inc f u Discrete Critical value s Results Or H Slope Critical Bias 1 Se k ss 10 0 10 DC Current Figure 6 2 LSATI Example Printout Page 33 RIA User s Manual Integral Solutions Int l March 31 2010 7 Inductance Saturation Field Test The LSATF 15 Inductance Saturation Field Test The test sweeps magnetic field and measures inductance at each field value Before displaying the results the test subtracts the LSATOffset from each data point which is inductance measured with RIA 2008 Setup parameters D x H8 Grade Cycles Time Date Time 2 Average 1G T Dem 1 7 2005 18 51 09 LI A n 1012 1 177 ziii 10 1 i vier umet 5 Graph LSATF 1 Inductance Saturation Field Test 25 B un 09 Fie
77. et To QST 2002 DC power for QST 2002 To quad pole magnet 2 pin Female connector for Transverse coils To QPS Splitter Output BNC X field output control To QPS Splitter Output DB9 X QPS communication To LISVAC outlet To quad pole magnet 2 pin Male connector for Longitudinal coils To QPS Splitter Output BNC Y field output control To QPS Splitter Output DB9 Y QPS communication USB To computer digital IO DC Power Inlet No Connect Input BNC To QST 2002 Field 1 output Page 10 RIA User s Manual Input 9 Output BNC X Output DBO X Output BNC Y Output DB9 Y Output BNC Z Output DB9 Z RIA Controller DC Power Inlet USB 40pin Ribbon RIA Module 40pin Ribbon SMA Quad pole Magnet 2 pin Female 2 pin Male Integral Solutions Int l March 31 2010 To QST 2002 DB9 To QPS 1050 BNC To QPS 1050 DB9 To QMS 1050B BNC To QMS 1050B DB9 No Connect No Connect To 48V power supply included To Computer digital IO To RIA Module mounted on 2xHGA Cartridge To RIA Controller To 2xHGA Cartridge To QPS 1050 9 pin round connector To QMS 1050B 9 pin round connector Page 11 RIA User s Manual Integral Solutions Int l March 31 2010 2 4 Connection Diagram Figure 2 1 RIA System Connections Page 12 RIA User s Manual Integral Solutions Int l 2 5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 March 31 2010 Running 15 Time Tu
78. flying the head The principle of the RIA measurement suite is characterization of the magnetic part of write head inductance and changes of inductance while applying specific combinations of external multi directional magnetic fields and DC write currents Q What Is write head inductance Inductance is a basic physical property of the write head A simplified write head structure is a coil wrapped around magnetic material yoke If the yoke Is removed e g saturated by magnetic field or defective then the write head inductance is decreased If the yoke dimensions are larger than nominal the write head inductance will increase compared to nominal The value of inductance is determined by many factors yoke magnetic material permeability domain structure geometry etc Head inductance changes when DC current and or magnetic field is applied to the write head RIA tests measure these small inductance variations and extract information relevant to write head defects and performance Q What is relative inductance A Magnetic write head inductance 15 extremely small For most modern write head designs this inductance is lower than 1 nH nano Henry 10 Henry For comparison parasitic electrical inductance of interconnect and cables is orders of magnitude higher Even slight misplacement of the interconnect cabling can change inductance by several nH In order to discriminate between the head inductance and parasitic inductances due t
79. h and working on new test applications and measurements We have developed new methods for measurement of flare geometry and magnetic response yoke anisotropy coil yoke coupling and others Patents Pending As the new ISI RIA system moves to head engineering and development areas new test applications will continue to be developed Page 88 RIA User s Manual Integral Solutions Int l March 31 2010 22 Appendix C Gen3 Probe Card RIA compatibility Gen3 Probe card p n 112830 needs to be reworked to become compatible with RIA operation Please contact ISI for more details QM G3 Probe card p n 114650 and Wafer Probe Card p n 114730 do not require additional reworks Page 89 RIA User s Manual Integral Solutions Int l March 31 2010 23 LIMITED WARRANTY Integral Solutions Int l a California Corporation having its principal place of business at 3000 Olcott St Santa Clara CA 95054 Manufacturer warrants its Quasi Static Tester model QST 2001 products the Products as follows Limited Warranty Manufacturer warrants that the Products sold hereunder will be free from defects in material and workmanship for a period of six 6 months from the date of purchase If the Products do not conform to this Limited Warranty during the warranty period as herein above specified Buyer shall notify Manufacturer in writing of the claimed defects and demonstrate to Manufacturer satisfaction that said defects are covered by this Li
80. his stress option allows to set field vector angle on the quad pole magnet The stress expects two values separated by semicolon The first is XY angle which is the angle in transverse longitudinal plane Valid settings include 180 to 180 degrees For example 90 0 will change to longitudinal field output The XZ angle is reserved for future use and should be set to 0 The Field Angle stress will remain for the duration of the test unless the test has field angle as a parameter Field Control Static Field X Pole Oe This sets the transverse coil set to a fixed field output Whether the setting will be applied or not depends on static field overrides angle setting in the QPS Splitter application and is described in more detail there X pole is the transverse output Y pole is the longitudinal and the Z pole is not supported The static field can be set to any value from negative to positive max field RIA 2008 Write Bias Enable Use this stress to turn on write current to the writer Valid settings include 0 to turn off write current and 1 to turn on write current RIA 2008 Write Bias Value Use this stress to change the write current value If the write current is turned off write bias enable 0 this stress will not do anything Write current can be positive negative or zero The maximum value for the write current is 125mA Page 24 RIA User s Manual Integral Solutions Int l March 31 2010 3 6 Runtime
81. ive or back the increment can remain positive all the time Write sweep critical values can also be set These will be used to calculate Critical Bias lt gt results The critical value returned will be the closest point found on the curve no matter if it occurred first or second So if the one point is 40 and the second point is 48 while critical value is at 45 then the second point will be considered critical value at 45 This is especially important to understand for cases where the waveform changes direction not just the slope The test generates two sets of data at write current and various fields and at critical field but various write currents Under the raw data tab both of these will appear To see the field sweep portion user can select vs Field in the Graph combo box To see the write current sweep user can select vs Bias in the Graph combo box The Inductance statistical result shown under the Results tab will be calculated only from the second set of data write current sweep at critical field value 8 1 Setup Parameters Average This is how many measurements to take at each field during the first stage of the test and then at each write current during the second stage of the test Page 37 RIA User s Manual Graph vs Field vs Bias Field From Discrete Field Critical Value s Write Current From To and Increment Dis
82. ld Sweep OHAN HHHH HHH Discrete Critical value s pox Fre Conditioning From 2500 2500 Inc 100 Results Data Parameters Grades E Inductance rH cm 0 3 392 Inductance rH Figure 7 1 LSATF Parameters The field be negative positive and zero The sweep pattern can be set by specifying from to and increment or by setting discrete values The sweep pattern can go from negative to positive or back The test can extract the field where the inductance value reaches certain value This 15 called critical value and the threshold or thresholds are user defined For example the test can return the field Oe where inductance reaches 50 To do this the test will find the maximum and minimum inductances measured during the test scale the difference as 100 and will find the field where inductance was closest to 50 More than one critical value can be specified but they need to be separated by semicolon If the critical value number has sign next to it then the software will determine the value to look for first using min and max inductance If there 15 no percent sign then the software will look for the actual inductance value For example 0 5 would indicate 0 5rH to the software while 30 would indicate Lmin 0 3 Lmax Lmin 7 1 Setup Parameters Average This is how many measurements to take at each field Note that this parameter does not apply
83. m the tooling side Relative Inductance value at positive field This is the statistical result Ave Max Min etc from the rH in raw data Each data point is the delta between the inductance measured and the LSATOffset parameter This is plotted in yellow color Relative Inductance value at negative field This is the statistical result Ave Max Min etc from the rH in raw data Each data point is the delta between the inductance measured and the LSATOffset parameter This is plotted in blue color Page 48 RIA User s Manual Integral Solutions Int l March 31 2010 Inductance Delta The difference between inductance value measured at positive field rH and negative field This 15 also plotted In red color Hysteresis The area between the positive and negative inductance curves 13 3 Example Printout YHDFT 1 Yoke Hysteresis Domain Field Test __ 4 Grade Cycles Test Time Date Time PatlD c 100 2387 YHDFT I 1 7 200 1854177 C S Cycles 100 YHDFT 1 Yoke Hysteresis Domain Field Test nd Write Current m eres UU Field Magnitude 500 ain Field Angle deg 0 22d el x p Fest Mas HHE DM Em o m 17 a zm m Inductance rH 0 401 0 405 Lr Inductance DelarH D 0 002 0 002 451571 u
84. mited Warranty If the defects are properly reported to Manufacturer within the warranty period and the defects are of such type and nature as to be covered by this warranty Manufacturer shall at its own expense furnish replacement Products or at Manufacturer s option replacement parts for the defective Products Shipping and installation of the replacement Products or replacement parts shall be at Buyer s expense Other Limits THE FOREGOING IS IN LIEU OF ALL OTHER WARRANTIES EXPRESS OR IMPLIED INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE Manufacturer does not warrant against damages or defects arising out of improper or abnormal use of handling of the Products against defects or damages arising from improper installation where installation is by persons other than Manufacturer against defects in products or components not manufactured by Manufacturer or against damages resulting from such non Manufacturer made products or components Manufacturer passes on to Buyer the warranty it received if any from the maker thereof of such non Manufacturer made products or components This warranty also does not apply to Products upon which repairs have been effected or attempted by persons other than pursuant to written authorization by Manufacturer Exclusive Obligation THIS WARRANTY IS EXCLUSIVE sole and exclusive obligation of Manufacturer shall be to repair or replace the
85. n opening 1512010 Diagnostics menu do this select Quasi97 gt Add ins Peripherals The following menu will be shows with the serial number of the RIA circled lt C Documents and Settings ISI Valued Customer Desktop sRIA QC mds Calibrate Add Ins Diagnostics Help 1 n Modules Static Tests 1 Selected Modules Peripherals Figure 3 12 RIA2008 Serial Number This information can be submitted to ISI and ISI will send out the RIA 2008 lic file At that point user should overwrite the file with the new in c program files integral solutions int NRIA 2008 Note that the older RIA 2008 lic file should be moved to a safe location in case there 15 a need to downgrade to previous version of software Obtaining a two week evaluation license is possible Contact ISI sales for more information WriterTM Evaluation Notice xj This an evaluation It will expire in 12 days receive a registered please contact Integral Solutions Int l at 408 653 0300 Figure 3 13 RIA2008 Evaluation Page 25 RIA User s Manual Integral Solutions Int l March 31 2010 3 Running RIA on BlazerX6 and Wafer The option is also available for Bar configuration on high frequency FMR option or low frequency probe card When using RIA with 2xBar Gen3 LF standard probe cards the capacitors C38 C39 C42 C43 C46 C47 C50 C51 will need to be removed This will
86. nch supplied with the tester 4 Push the magnet towards the tooling and tighten the screws lightly The Y position of the magnet will depend on the type of cartridge installed UP or DOWN Page 14 RIA User s Manual Integral Solutions Int l March 31 2010 5 Remove the 2xHGA G2 tooling from the QST 2002 6 Install the quad pole tooling adapter on the baseplate 7 Substitute the 50 ribbon cable with the longer one supplied in the upgrade kit 8 Install the 2xHGA 02 tooling back on QST 9 Remove the white pomalux cover from the 2xHGA tooling Page 15 RIA User s Manual 10 11 12 13 14 15 Install new cartridge onto the 2xHGA base Connect the SMA cable from RIA Module to the HGA Cartridge screw on the connector until tight Install the RIA module onto the 2xHGA board The 40pin ribbon connector should point to the back of the QST 2002 Loosen the hardstop refer to QST 2002 manual for hardstop adjustment Move the cartridge all the way towards the magnet The cartridge should be as close as possible to the magnet but not touching the poles Tighten the hardstop at this position vill A 2 re 4 1 2 E ZA Page 16 Integral Solutions Int l March 31 2010 RIA User s Manual 16 Adjust the position of the 17 magnet so that the head is in the center spot between the 4 poles C
87. ncy sweep Q How to setup RIA tests for selecting good defective write heads Inductance changes caused by DC current and magnetic field generate a specific head signature This signature contains a number of features such as inductance kinks corresponding to saturation of different yoke regions and their shifts depending on DC current and external field angle These Signatures are determined by specific head designs yoke dimensions material properties coil design and others Understanding and interpreting these detected features often require detailed knowledge of the head design and micro magnetic modeling Major yoke and coil defects can be usually detected comparing changes of relative inductance with or without nominal DC current DC field or exercising the write coil with simultaneous external field bias More detailed analysis e g selecting weak writers with insufficient overwrite requires well established baseline This baseline can be generated by comparing a set of normal and defective structures and exercising standard RIA tests such as inductance current saturation current field Saturation coupling hysteresis yoke anisotropy and others Once a normal head signature is established the defective sliders can be detected by comparing a set of measurements of any test Sample vs the established baseline Once again remember to compare apples with apples design modifications of write head mate
88. ng RIA software Without RIA 2008 Application module or QPS Splitter Application modules the quad pole magnet can still be used and will apply transverse field RIA system is used to characterize the writer and the a few QST 2002 capabilities were removed due to electronics hardware design When working with RIA the high frequency tests such as SMAN Popcorn and others are not functional User can still run tests utilizing the low frequency channel such as Transverse and Quasi Static test At any time the system can be converted back to restore full reader measurement functionality RIA module can be connected only to one channel at a time User has a choice of installing UP or DOWN HGA connector board For one type of board the reader will need to be connected to channel closest to the front of the machine and for the other type reader will be connected to channel 1 Both 3pin cable and ribbon cable need to connect to the same channel The RIA Module SMA cable stays in the same place Refer to the figure below for details Warning The 4pin writer cable on the 2xHGA cartridge should be disconnected for all RIA tests 2xHGA writer preamp chip if connected to the writer will interfere with inductance measurement Page 18 RIA User s Manual Integral Solutions Int l March 31 2010 Figure 3 1 RIA configuration CHO vs Page 19 RIA User s Manual Integral Solutions Int l March 31 2010 3 1 Starting Software
89. ng in mind that any minor change of the system such as disconnecting and connecting cables or replacing the probe will cause baseline shift equal to or exceeding the calibration value What is the frequency of ISI RIA Measurement Can this frequency be changed Standard 151 RIA system measures a single frequency inductance value at approximately 250 MHz This is the only frequency point for RIA analysis the frequency can not be swept This measurement frequency was carefully selected based on extensive research Inductance frequency response of modern write heads is practically uniform from near DC to 300 400 MHz range This means that 250 MHz measurement 15 similar to inductance measured at lower or higher frequencies This frequency 15 within the typical write head operating range of the disk drive 250 MHz frequency provides a high measurement resolution while still allowing the usage of conventional probes for Wafer Bar Slider testing and conventional pogo pin interconnects for HGA testing and also is well within the operating bandwidth of the HGA flexure Some frequency modifications 210 380 MHz are possible but require hardware redesign by 151 Q What new information can be obtained using RIA testing The short answer is almost all information obtained with the RIA system is new Currently write heads are not tested statically on Bar HGA level with the exception of basic resistance and in some cases wafer lev
90. o such things as cabling the parasitic inductance has to be removed This is achieved by saturating the write head sufficiently strong magnetic field 2500 Oe for 151 RIA system When the magnetic field is applied the write head yoke saturates and its inductance drops to zero value The residual measured inductance value determines the measurement baseline and equals to the total electrical inductance of cabling interconnect probe and the write coil RIA measurements are taken by subtracting this baseline from the write head measurement relative measurement and thus corresponds to the magnetic inductance contribution of the write head To measure this small write head inductance contribution the RIA provides an extremely high resolution 1 pH 1 1000 nH relative inductance measurement This is achieved by applying a Small about 1 mA 250 MHz tickling signal to the write head coil and using a proprietary 151 circuitry for discriminating parasitic and magnetic contributions to inductance Q Can RIA measure absolute inductance Standard RIA tests report relative inductance values In a general sense there Is a possibility to calibrate the 151 RIA system to report absolute inductance values This requires a fixed setup configuration and a known calibrated sample with small Several nH inductance value The calibration Page 85 RIA User s Manual Integral Solutions Int l March 31 2010 should be done with extreme care keepi
91. ole magnet which includes the second magnet power supply and the QPS Splitter module The QPS Splitter is responsible for setting the field angle but it can also set fixed static fields The QPS Splitter module is controlled by QPS Splitter exe application This application is automatically loaded with 2008 test suite The main software module to run the tester is Quasi97 In order to enable RIA capability user must add 2008 A pplication to the Add Ins Selected Modules This adds a suite of writer tests to the setup file as well as the field angle and writer specific stress options Adding RIA 2008 Application is required for every new setup file The system also uses 2xHGA Gen2 base for standard reader measurement so System Tester Configuration must be set to 2xHGA G2 The maximum field setting in the System menu must be set higher to about 3000 3500 Oe in order for the tests to work Add Ins Peripherals gives you access to RIA controller and QPS Splitter application menu These menus are primarily for diagnostics but can be used to manually set field vectors calibrate inductance values and so on This user s manual contains two sections describing these options in more detail User can also start QPS Splitter exe application on its own to control the field and angle outside of Quasi97 The QPS Splitter Application can also be added to the Quasi97 Add Ins Selected Modules to enable field angle stress without activati
92. om the tooling side Discrete If this option is turned ON then the From To and Inc are ignored and the semicolon separated values from the adjacent textbox are used For example 90 45 0 10 20 30 40 50 Page 44 RIA User s Manual 11 2 Critical Value s Results Relative Inductance rH Critical Field Pos lt gt Critical Field Neg lt gt Integral Solutions Int l March 31 2010 Semicolon separated critical values The values can be numeric or a number followed by the symbol The difference is explain the introduction for this test Inductance value is the statistical result Ave Max Min etc from the rH in raw data The rH raw data is the relative inductance at each field angle Each data point 15 the delta between the inductance and the LSATOffset parameter The field angle where the critical value was found The software discriminates between positive and negative angles this result reports the value found among positive field angles including 0 For each critical value the test will add a Critical Field Pos lt gt result For example the first critical value will be Critical Field Pos 1 The returned result will be in degrees The field angle where the critical value was found The software discriminates between positive and negative angles this result reports the value found among negative field angles including 0 For each critical value the test will ad
93. onnect the RIA module to the RIA controller box using a 40pin ribbon cable supplied Note that the RIA controller has to be off plugging it in while the power is on may result in equipment damage Page 17 Integral Solutions Int l March 31 2010 RIA User s Manual Integral Solutions Int l March 31 2010 2 Tester Basics In order to turn on the RIA system all of its components must be powered on including RIA Controller QMS 1050B QPS 1050 QST 2002 of those and the QPS Splitter modules have an LED indicating of whether the power is on The system consists of three functional components The first QST 2002 is test electronics module that 15 responsible for supplying reader bias current measuring reader resistance amplitude noise characteristics and so on The QST 2002 needs QPS 1050 to work and the transverse field magnet The magnet can be connected directly to the QPS 1050 or through the QPS Splitter box Originally QST 2002 is connected to the writer to apply write stress and measure writer resistance but 1 could not measure writer inductance The second component is the RIA module which is responsible for measuring inductance The RIA component connects to the specially modified cartridge via SMA cable There is a separate software module that controls it which is automatically loaded with RIA 2008 test suites and is available through Add Ins Peripherals menu Quasi97 Third component is the quad p
94. r box do not require any cooling Page 9 RIA User s Manual Integral Solutions Int l March 31 2010 2 2 Arrival Checklist The RIA System is an add on so the items included in the shipment may differ from the list below The following list is a guide of what items should be present in order for the RIA system to work properly 1 2 3 4 5 6 7 2 3 QST 2002 Electronics USB Cable b 14 pin Round Cable BNC Field Control Cable d M M DB9 Cable QPS 1050 Power Supply a AC Power Cable b Opin round to 2 pin flat Transverse Coil Cable QMS 1050B Magnet Power Supply AC Power Cable BNC Field Control Cable transverse field DB9 Cable transverse field BNC Field Control Cable longitudinal field M M DB9 Cable longitudinal field Opin round to 3 pin flat Longitudinal Coil Cable QPS Splitter a USB Cable Type B square RIA 2008 Controller a USB Cable Type B square b 40 pin Ribbon cable RIA Module Quad pole Magnet mo Boge Connections QST 2002 USB 14 pin round Air Inlet BNC Field 1 DB9 QPS 1050 3pin AC Power 14 pin round 9 pin round BNC DB9 QMS 1050B 3pin AC Power 9 pin round BNC DB9 QPS Splitter To computer digital IO To QPS 1050 DC power for QST 2002 To compressed air inlet for pneumatic actuator To QPS Splitter Input BNC field output control To QPS Splitter Input DB9 QPS communication To 115VAC outl
95. ral 1 Data Logging 1 Login Parameters Auto Clear Results Grading Keyboard Shortcut ta Start Production Key 1 Space Key 2 Nene Heads Normalization Normalize By Tester 5M Failure Production Warring Enable Show Warring After 3 Consecutive Part Failures warning Message pu Threshold Reached Please Verify System Settings Figure 3 15 Alternative Test Site With this setting production test will have two test sequences for test site and stress site User should add RIA tests to the alternative test site When running production test the system will go through all heads on the bar at the test site and will then switch to stress site where it will run RIA tests on all the heads that have passed grading so far Page 26 RIA User s Manual Integral Solutions Int l March 31 2010 Magnes Flesittan 000 Encoder Temp Figure 3 16 RIA on BlazerX5 Production Test In engineering mode through Barcont user can switch to stress location and then select heads through Quasi97 and run RIA tests on each head individually w ISI Bar Controller Tray Tester Diagnostics Help Bar Alignment Bump list Edge Y Offset 2ndEdge OpticalPadAtion YSealeEffect 0 F gt Manual Move Status Relative Hardware Bumpin Pick UP Put DN fe PutDown Haviqator Tray Bar 77
96. ral Solutions Int l March 31 2010 20 4 Coil Yoke Coupling Efficiency Test patent pending This test is designed for analysis of write coil yoke interactions The LSATF test sweeps external magnetic field while CYCET test sweeps DC write current when the magnetic field amplitude and angle are fixed A simple explanation of the CYCET test is shown the next figure Figure 11 Illustration of CY CET test principle When the write head is placed in transverse external magnetic field the yoke is partially saturated magnetization direction is shown by red arrows The write coil generates magnetic flux which opposes the external field and the main pole saturation is determined by two competing factors external field and write current When DC current is swept from smaller to larger values the yoke saturation is decreased and inductance value becomes larger The CYCET test reports inductance changes for different DC current values An example of CYCET test for two heads is shown in the next figure Page 73 RIA User s Manual Integral Solutions Int l March 31 2010 CYCET 1 Coil Yoke Coupling Efficiency Test 5 head18 11 02 35 1 75 1 00 0 75 0 50 0 25 5 10 15 2 2 30 5 40 5 5 5 6 DC Write Current mA CYCET 1 Coil Yoke Coupling Efficiency Test A head16 11 00 09 Relative Inductance rH O 1 75 1 00 0 75 0 50 4 0 25 5 10 15 2 25 30 5
97. re 16 2 Writer_Res Example Printout Page 55 RIA User s Manual Integral Solutions Int l March 31 2010 17 Calibration 17 1 Inductance Inductance calibration is performed at the factory and does not need to be recalibrated by user Even though the absolute value may differ from tester to tester the RIA 2008 tests produce relative inductance results which correlate from system to system If additional normalization is needed 115 recommended to use custom results normalization parameters in Quasi97 The following brief explanation of the calibration process is for reference only The inductance calibration involves mounting two inductors 3nH and 4nH of known value to the end of the SMA cable There is a button Calibrate Inductance in the ISI2010 software that runs the calibration procedure To calibrate 1 Mount one 3nH inductor 2 Open 1512010 gt 2 16 gt diagnostics menu 3 Click Calibrate Inductance 2 RIA 4 lt RIA 001 gt button Status HEX EEPROM EEPROM 4 Click OK button x Base Addr Registers PIRIADT CARD 4 Wr Head 5 Mount the 6 5nH inductor Bead wie 6 Click button 208 7 Click Write to eeprom to Bis OFF Bison save the calibration values nductance Offset 30 40862 127 5315 485553 474741 SetBias MeasFreq Delay m5 Measurements Number of 5 amples Resistance vo
98. rence is explain the introduction for this test An option to scale all results considering minimum inductance measured during the test as and maximum as 1 This option allows to user to choose whether to plot the Slope or the Inductance This has no effect on the statistical results or Data Relative Inductance value which should be similar to nH This is the statistical result Ave Max Min etc from the rH in raw data The rH in raw data 1s the relative inductance at each write current Each data point is the delta between the inductance measured and the LSATOffset parameter The relative inductance slope This 1s the statistical results from rH slope at each write current For each critical value the test will add a Critical Field lt gt result For example the first critical value will be Critical Field 1 The returned result will be in Oe The lt gt does not depend on the critical value parameter but on the placement in the string For example for critical values 0 5 20 Critical Field 1 is the field current where rH 0 5 and Critical Field 2 is the magnetic field where rH is 20 of the range Page 35 RIA User s Manual 7 3 Example Printout aa LSATF 1 Inductance Saturation Field Test Hd Grade Cycles Test Time Date 1 7 2005 18 51 09 I m o E m a E m z m na Clear ResulkszFlat 3 077 anncid o E4 nc LSAT
99. rial and geometry will likely require generating a new baseline Q How does the ISI RIA system compare to commercial LCR meter and Network Analyzers What are advantages and disadvantages of ISI RIA compared with network analyzer measurements RIA provides fast lt 5ms and ultra high resolution about 1 pH 1 1000 nH relative inductance measurement with accuracy of 10 pH This is far beyond the specs of most LCR meters or Network analyzers typical resolution is higher than 0 1 nH Another advantage of the RIA system 15 hardware integration of RIA with standard 151 QST measurements tooling and quadrupole magnet control These unique features provide highly detailed and fast write head inductance characterization One on paper disadvantage of 151 RIA implementation is that it provides relative measurements However reality most of inductance measurements at less than 1 nH level are not absolute For example absolute inductance measurement with Network Analyzer requires special calibration procedures such as using special probes and calibration substrates Further simply changing the setup Page 87 RIA User s Manual Integral Solutions Int l March 31 2010 from calibration mode to an actual write head measurement may introduce an error comparable to at least 0 2 0 5 nH or more Q Can RIA testing be performed at Headstack HSA or Drive HDD level No RIA testing requires a precise connection between the
100. rite H ext 1 234 Read Read Debug hex 0 USEPA 12 EERPRDH na device ce SDI write ina 0000 SDD Read device 912 EEPROM ID NEW EE Size 2 8000 Backplane Add EEPROM device c Address 2 2 Addr 0 device 5 na device cb 7 BackPlane Skip Timer Hardware Present Backup File Write z Read Figure 18 1 ISI2010 Diagnostics Menu 18 3 Hall Effect Cartridge The standard hall effect cartridge will not work with the new magnet because the gap is much smaller than on standard HSA magnet Figure 18 2 Hall Effect Cartridge Page 61 RIA User s Manual Integral Solutions Int l March 31 2010 18 4 Quad Pole Magnet Calibration Adaptor This tooling helps position the gaussmeter probe at the center of the uniform field and at the right angle to the generated field This adaptor is made especially for HGA quad pole magnet The gausmeter probe can be inserted in transverse or longitudinal directions Figure 18 4 Gaussmeter Probe Page 62 RIA User s Manual Integral Solutions Int l March 31 2010 19 Troubleshooting 19 1 FAQ XXXXX Board not detected The inductance level at higher write currents becomes higher During Initialization the QST 2002 reads all board EEPROM s and verifies board communications No system has every board we have built so it is to be expecte
101. rn ON the PC monitor Check that the operating system boots up with no problems Turn ON the QPS 1050 ensure that the Power LED is ON Turn ON the 5 105 ensure that the Power LED 15 ON Turn ON the QST 2002 ensure that the LED front panel is ON Turn ON the RIA module Ensure that the LED on the front panel is ON Check the LED in back of the QPS Splitter box next to USB port is Start Quasi97 select a setup file In the system menu select 2xHGA 02 In the Add Ins Available Modules add item RIA 2008 Application In the Add Ins Selected Modules add new item and selection 2008 Close the dialog box At this point the software should detect RIA module and the QPS Splitter option In the System menu change the maximum field to 3500 Oe The RIA system is single channel even though the cartridge can have two HGA connector boards installed only one of them can be connected to the RIA Module To avoid confusion it may make sense to disable the other channel in the Tools Options menu Note You may need to repeat steps 11 12 and 13 every time you create a new setup file Click START in Quasi97 Add an instance of LSATF test and run it This will check the that the hardware is operating properly The outcome of the test will depend on the head installed so at this step it only matters if there are any errors Check the Active LED on the QPS 1050 it should turn on for a
102. round RIA 2008 Setup is added as a variable to the Dependent Parameters in Quasi97 which works almost the same way as Adaptive Parameters but is not visible to user and cannot be turned off by the user So every time user runs RIA 2008 test Quasi97 will measure LSATOffset by setting write current field and number of iterations as they are defined in this menu In production sequence the LSATOffset is measured only once 4 1 Setup Parameters Iterations The number of measurements to take to calculate AVG inductance Minimum is and maximum is 1000 with the default set to 10 Each measurement will be shown under the DATA tab and on the plot The LSATOffset will be the average of those measurements Saturation Field The field in Oe at which all tests should measure the saturated writer Oe inductance This is limited to maximum field specified in the system menu Writer inductance changes with external field but the response is not linear At higher fields the response inductance vs field is almost flat this 15 where the head 15 saturated This field value should be used to for LSATOffset calculation Write Current mA The write current to be applied during the test Typically this is not necessary the field alone is enough to get the saturation value Preconditioning This option allows user to define more complex stress and use that Only instead of Saturation field and Write Current parameters If this option is enable
103. t results on sliders from the same bar The next graph illustrates write head with strong field polarity asymmetry Normal head Strong saturation Asymmetry 1 4 4 gt 1 2 rs 0 8 0 6 0 4 0 2 y 0 2500 2000 1500 1000 500 0 500 1000 1500 2000 2500 Field Oe Figure 9 Asymmetrical head response This asymmetrical LSATF signature indicates strong tilt of yoke flare magnetization and possibly a special type of magnetic defect where yoke inductance kinks occur at 600 Oe and 1300 Oe This results in strong polarity dependent asymmetry of recorded transitions one particular direction of write current is preferable for stronger field generation while the opposite polarity is not favorable Page 71 RIA User s Manual Integral Solutions Int l March 31 2010 The LSATF test combines the field inductance saturation curve with DC current excitation Polarity of DC current determines direction of the flux generated in the yoke For one polarity of the write current combined with transverse magnetic field saturation this flux direction coincides with the external field direction causing stronger yoke saturation For the opposite polarity magnetic flux generated by DC current is opposite to the external field and yoke saturation is decreased Additional flux generated by DC current causes shifts of the LSATF saturation c
104. te Current Sweep From 50 Inc Discrete Measure Angle Width 22 502 Fre Conditioning YAT YAT Bias Sweep 0 375 0 550 0 525 Figure 12 1 Sweep Parameters The test can plot all field angle curves superimposed if graph rH 3D is selected or Just plot angle width This plotting option can be changed after the test runs With the 3D option inductance waveforms are plotted using different accent of the same color The test also supports displaying multiple results With this the new result will be plotted using a different color 12 1 Setup Parameters Average This is how many measurements to take at each field Field Magnitude The magnitude of the field vector to apply during the test Oe Field Angle Sweep The sweep parameters for the test The From can be positive negative or zero and so is To parameter Increment parameter cannot be set to 0Oe 0 degrees is considered Transverse 90 degrees 15 considered Longitudinal counter clockwise if looking at the magnet from the tooling side Discrete If this option is turned ON then the From To and Inc are ignored and the semicolon separated values from the adjacent textbox are used For example 90 45 0 10 20 30 40 50 Field Angle Semicolon separated critical values The values can be numeric or a Critical Value s 9o Write Current From To and Increment Discrete number followe
105. tegral Solutions Int l March 31 2010 3 2 Installing HGAs Once the hardware detection is complete and setup file 15 open it is now safe install HGAs on the tester The cartridge cannot be removed from the 2xHGA base so an HGA has while cartridge is on the tester Slide the 2xHGA board away from the magnet until it hits hard stop If the air is connected to QST 2002 then simply click STOP and let actuator move the tooling away from the magnet At this point the bias is turned off and it is safe to open the HGA connector lid and put in the new head Figure 3 4 Installing an HGA For easier placement the HGA should be placed on the pole and then pivot the tale to the pogo pins After placing the HGA close the lid pull the locking lever back again to close the lid The cartridge should be installed while the bias is off Click START button in Quasi97 to turn on the read bias to the head Note that the write bias will be off by default until user runs the test User has to select appropriate channel in order to get valid results The picture above shows HGA connector installed on CHO CHI position is the furthest from the front of the machine To choose a different head simply switch the head selector on the lower right corner of the screen to a different number Run Test s Figure 3 5 Installing an HGA If the software cannot select one of the heads then the head 15 disabled in the options menu under Heads
106. ts to the test tree The tests include LSAT LSATF YHDFT YDT MMT etc These modules are described in more details in the sections to follow All writer tests except for Writer_Res require measuring writer inductance at high magnetic field where the writer inductance 1s saturated All inductance measurements will be normalized to this value LSATOffset This is achieved by using parameters from RIA 2008 Setup module Unlike other tests RIA 2008 Setup cannot have multiple setups and is automatically added to adaptive parameters for every new instance of the test Every RIA 2008 test measures saturation value at the beginning and then uses this value to calculate inductance results In the production sequence the LSATOffset will be calculated only once for the sequence of tests All of RIA 2008 tests support adaptive parameters and sweep test User can change one or more of its parameters prior to running based on some formula from the user For example Integral Solutions Int l March 31 2010 Note4pp 4pplication SWeenAa pp Application AlAZO08 APPLICATION be m HlA 2008 Setup gilt writer Res Hz LSAT LSATI Eee YDT E x 28 YAT FER VAT Sweep a YHDIT Figure 3 8 Add Ins Adaptive Parameters v Enable Adaptive Test Parameters Adaptive Parameters New Setting m
107. urve An example of such test is shown in the next figure 1 8 1 6 5 Current 0 14 Current opposite to field N J Inductance 2 Current amp Field Same direction 0 2 0 500 1000 1500 2000 2500 Field Figure 10 LSATF test with two different polarities of DC current When DC current is disabled the inductance kink occurs at 1000 Oe This field is called the critical field in RIA terminology However when 30 mA DC current is applied in a direction coincidental with the magnetic field direction the kink occurs at 600 Oe external field The opposite DC current polarity shifts the kink of inductance to 1200 Oe The amount of flux generated by DC current is determined by coil quality and coupling efficiency i e how effective is magnetic interaction between the write coil and the yoke This test is very sensitive to coil defects changes of coil geometry effective number of turns coil yoke spacing and position variations cause differences in inductance kink locations In many cases this test correlates with dynamic write head performance parts with larger kink shifts are more effective writers with better overwrite performance and vice versa The RIA test software determines and reports LSATF critical field shifts for parts screening and diagnostics Page 72 RIA User s Manual Integ
108. ve Inductance value measured in reverse sweep This is the statistical result Ave Max Min etc from the rH raw data Each data point is the delta between the inductance measured and the LSATOffset parameter This is plotted in medium thickness dashed line The difference between the Inductance Pos and Inductance Neg results The area between the forward and reverse inductance curves 15 3 Example Printout 1 Magnetic Memory Test Relative Inductance Delta Inductance Grade Cycles Test Time Test fTime PatlD 2514 MMT 1 1 7 2000 185457 O Sweep Field MMT 1 Magnetic Memory Test Average EE For 6 54 57 PM 2000 1500 1000 Rew 6 54 57 Deta m DSt EM Field Angle deg 0 Write Current m 40 Fre Conditioning Field De 250 Sweep From 2000 2000 Inc 100 Discrete E Results Parameters Grades Inductance Pos rH 0 246 0 394 0 3 E D Hysteresis 5 NNI te ALL A 500 1000 1500 2000 Figure 15 2 MMT Example Printout Page 53 RIA User s Manual Integral Solutions Int l March 31 2010 16 Writer Res Writer Resistance Test The Writer Res test measures resistance of the writer by using RIA 2008 hardware User can set write current field and the number of iterations pasurement OOOO
109. wide main pole and narrow recording pole is provided by the triangular flare region The function of the flare is to concentrate magnetic flux in the recording pole Flare shape angle and dimensions vary for different head designs Many heads feature double flare angles which optimize flux conduction to the recording pole region Page 65 RIA User s Manual Integral Solutions Int l March 31 2010 Recording pole Figure 3 Simplified cross track geometry section of recording pole Page 66 RIA User s Manual Integral Solutions Int l March 31 2010 20 2 Inductance Saturation using DC Write Current LSATI test DC write current supplied to the write coil generates magnetic flux in the yoke and saturates the head As the write current value is increased higher saturation is achieved and inductance is decreased This basic effect is demonstrated using LSATI RIA test shown below LSATI 1 Inductance Saturation I Bias Test head21 11 06 07 1 6 1 5 1 4 1 3 1 2 pd gt a 09 t 0 8 0 7 0 6 0 5 5 10 15 20 25 30 35 40 45 50 60 DC Write Current mA LSATI 1 Inductance Saturation I Bias Test w head19 11 03 31 AM 1 75 1 50 I 125 9 5 1 00 0 75 0 5 10 15 20 25 30 40 45 50 60 35 DC Write Current mA Figure 4 LSATI current sweep for efficient top and less effi

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