4431T User Manual - Electro Tech Systems
Contents
1. The current RS shall have the clowns characteristics pulse rise time t 5 nanoseconds to 20 nanoseconds pulse decay time t 200 nanoseconds 20 nanoseconds ae maximum peak to peak ringing I shall be tess than 15 of with no observable ringing 100 nanoseconds after the start of the pulse peak current I shall be within 10 of the value specified in section 5 E Figure 2 0 2 Discharge waveforms per ANSI ESD STM5 1 The current pulse detected between the upper and lower electrodes of the Capacitive probe is used to calculate the energy inside the bag by integrating the area under the curve as shown in Figure 2 0 3 4 Ret sample 5 Teast Date Time 07 21 1998 14 08 13 Discharge Peak 24 8 mA Energy 16 19056 nJ 100 of Wave Captured Figure 2 0 3 Typical Model 4431 shielded bag waveform Six specimens of a given sample are required Six measurements per specimen is specified Testing is to be performed at both 12 and 50 3 RH ata temperature of 73 3 F after a conditioning period of 48 hours minimum Bag size for this test is specified to be 8x10 inches 20x25 cm ANSI ESD 11 31 specifies that the test conditions peak current minimum maximum and average energy levels of all 36 measurements be reported for bag qualification 2 2 ANSI ESD 11 4 Static Control Bags This standard defines the performance of static shielding bags used in man2. mA Energy 13 06916 nth Denk 24 mA Energy 12 6670 nh Peak 24 mA Energy 1240444 mb Figure 6 0 3 Typical verification and shielded bag waveforms 17 Transfer the data from the oscilloscope to the computer in accordance with the computer program protocol The ETS Energy Calculation Program enables the entire test sequence to be controlled by the computer Set the FUNCTION switch to AUTO nJ Follow the computer program protocol refer to the ECP Operating Manual to first activate the waveform verification test and then the measurement sequence required for the first soecimen Repeat the procedure for the remaining specimens At the conclusion of the test the computer will print out the peak current min max and average energy level and the standard deviation plus all other information per specification Figure 6 0 4 is a sample of the ECP printout ETS Model 4431 Energy Calculation Test Report V1 10 8 Test Standard ESD STM11 31 Static Shielding Bags Cisiomnei ETS PO 10 1099 Group DS12345 Reference 4 of Wave Captured 1400 Sample Size Test Tech HIEN Cal Peak Current mA 480 00 Cai Energy Level 49447 14 Date in Chamber 10 03 2010 Time in Chamber 9 00am Test Date 10 04 2010 Test Humidity 12 Ambient Humidity 12 Conditioning Period 30 Hrs Test Time 15 37 06 Test Temp 72 F Ambient Temp 72 F Chamber N A S Scope Type ID TEK TDS 20228 CF 91 7CT FV v24 02 Controller N A Probe 4 Type TEK CT Test System E
3. of volts as long as the bag does not deteriate The EIA 541 specifications for good and bad bags are totally different from the ANSI ESD STM 11 31 specification The energy and AV and not directly related to each other The AV of lt 30V is from MIL PRF 81705C The origin of this limit is unknown but was established over 20 years ago In addition the lt 30V AV is based on a 200pF 400k discharge network This network is far less sensitive than the 100pF 1 5k network used for evaluating good bags Either network can be selected using the front panel switch 6 0 OPERATION 6 1 Discharge Waveform Verification 6 1 1 ANSI ESD STM11 31 Energy ANSI ESD STM11 31 defines the discharge waveform but EIA 541 does not however both tests utilize a similar discharge pulse Therefore following the ANSI ESD STM11 31 verification procedure will also apply to EIA 541 testing ANSI ESD STM11 31 requires verification of the discharge current pulse both through a short to ground and through a 500 Ohm resistor This requirement is based on an assembled apparatus where the Discharge Simulator and the electrode assemblies are separate components The Model 4431 T is an integrated system where the discharge waveform at the discharge electrode is designed to meet the specified requirement 15 6 2 Prior to each test in the AUTO mode the waveform energy and peak current is automatically verified For verification testing before each test
4. a damp cloth Let dry before use Do not use detergent alcohol or antistatic cleaner as these products may have an adverse affect on system performance SERVICE Do not attempt to repair or service the instrument yourself unless instructed by the factory to do so Opening or removing the covers may expose you to high voltages charged capacitors electric shock and other hazards If service or repair is required contact the factory 1 0 INTRODUCTION The rapid advancement in the electronics industry during the past decade has placed increasing importance on the understanding of electrostatics and its effect on electronic devices and systems Electrostatic Discharge ESD is a common cause of microelectronic circuit failure Many of these devices can be seriously damaged or destroyed by an electrostatic discharge below 30 Volts or as a result of an electrostatic field of only a few hundred Volts The static shielding bag was developed to provide a package that would protect static sensitive components placed inside from external ESD events Many different bag constructions are now available that when properly used provide a Faraday cage electrostatic field attenuation around the objects placed inside The most common bags are constructed from transparent polyethylene film with a metalized layer of mylar laminated to either the outside or the inside of the bag The metalized side is either on the outside metal out or buried between the
5. bm gem Bt Te ec tno ven mm emm L i Fajai ne E Lol kel kel m n em em em E gt ieia i Sit 2 Ff Figure 5 0 2 Voltage differential test set up If the Model 4431 T is used to measure voltage differential the CT 1 current sensor must be disconnected and the Voltage cables connected to perform this test The Model 4431 T is shipped from the factory with the Capacitive sensor programmed for the Energy test To convert the System from energy to voltage differential the capacitive sensor must first be converted by plugging the red jumpers into the center and rear pins as shown in Figure 5 0 3 5 2 1 nd deitaV Figure 5 0 3 Capacitive Sensor conversion from energy to voltage R C Networks The user can select either of two R C networks using the front panel FUNCTION selector switch The commonly used 200pF discharged through 1500 Ohms or the EIA 541 specified 200pF discharged through 400 kOhms NOTE The 1 500 Ohm resistor will enable bags having surface resistances between 10 and 100 kOhms 100 and 10 000 Ohms sq to be differentiated On the other hand the 400 kOhm resistor will only be able to differentiate bags having surface resistances between 1 000 ohms and 1 Megohm 10 000 and 10 MegOhms sq Current industry practice is to use 1 500 Ohms 5 2 2 Oscilloscope The oscilloscope and Discharge Unit must first be calibrated as a set If the oscilloscope is supplied as part of the system the Discharge Unit and sc
6. ensuring consistent and repeatable results Included with the Model 4431 T is the interconnect cables and accessories shown in Figure 4 0 3a Figure 4 0 3a Model 4431 T cables and accessories 1 BNC BNC 2 cables for connecting voltage output signals to oscilloscope 2 BNC cable from CT 1 to oscilloscope Model 4431 T only 3 50 Ohm terminator 4 USB cable from computer to the oscilloscope Model 4431 T only 5 USB to serial converter with 9 pin sub D from computer to communications cable Model 4431 T only NOTE Do not sustitute 6 9 pin sub D from Converter to 25 pin sub D to Model 4431 T 7 Foot switch 8 IEC Line Cord North American plug Figure 4 0 3b shows the jumpers and cables required to perform first time set up 5 0 Cable to verify discharge waveform with external CT 1 SHIELDED BAG TEST SYSTEM AV ISk nj AUTO Shorting strap to connect Dischg and Capacitive electrodes together to measure 1kV Dischg waveform HV ON Figure 4 0 3b Calibration cables and jumpers for first time set up NOTE If the Model 4431 is used to replace a Model 431 discharge unit an adapter is required to convert the 25 pin COMM PORT to a 3 pin DIN to receive its command signals from the computer s PRINTER Parallel Port Contact ETS If the computer has only one output it is necessary to install an A B switch supplied with early versions of the ETS Energy Calculation Program to operate a pr
7. pin adapter and 25 pin sub D connector on the rear of the Model 4431 Connect the USB USB cable to the 1 computer USB port and the other end to the USB 9 pin sub D adapter Connect the USB USB cable from the oscilloscope to the 2 USB port on the computer Note Only connect after PC is on and finished booting In case of miscommunication with the oscilloscope unplug and re plug it _ If a printer is used connect it to the 3 USB port on the computer Confirm that the red jumpers located on the sides of the capacitive sensor are plugged in the center and front 040 pin jacks This programs the Capacitive sensor for current measurements Plug the phono plug from Foot Switch only when unit is off if used into the REMOTE DISCHARGE jack on the rear panel of the Model 4431 Power up all instruments Set the FUNCTION select switch to MAN ng if the test is to be controlled by the operator or to AUTO nJ if the test is to be controlled by the computer For waveform verification in the MAN mode set the oscilloscope VERTICAL sensitivity to 500mV the time base to 100nsec and the trigger level to 500mV For bag testing start with settings of 20 or 50mV 20nsec and 50 or 5mV respectively Otherwise the ETS Energy Calculation Program automatically sets the correct scope parameters EIA 541 Voltage Differential 10 Refer to Figure 5 0 2 for the set up for the voltage differential test Is SE lt a a I
8. series measurement of the waveform with the capacitive sensor through the CT 1 and the 500 Ohm resistor is required This measurement is performed by simply discharging directly to the capacitive sensor without a sample in place This waveform is shown in Figure 6 0 1 and should measure between 420 and 500 milliamps and have an energy of 50 000 3 000 nanoJoules at a 1 000 Volt discharge To measure the actual discharge waveform from the discharge output without the 500 Ohm resistor and capacitive sensor a separate CI 1 current transducer is required Place the Calibration Wire supplied between the discharge electrode and capacitive sensor upper electrode with the white insulator against the upper electrode Lock in place using the lever Feed the bare end through the CT 1 Insert the wire into the ground point as shown in Figure 6 0 1 The Discharge waveform per ANSI ESD STM 5 1 can now be measured Insulator Deeg oN CT 1 ee HN Figure 6 0 1 Calibration set up to measure ESD pulse 6 1 2 EIA 541 1988 Voltage Differential EIA 541 does not specify the discharge waveform characteristics However it is implied that the waveform meets the requirements of ANSI ESD STM 5 1 with the exception of the R C network The waveform will be similar but the rise and fall times will be longer Product Testing per ANSI ESD 11 31 ANSI ESD 11 31 specifies an 8 x 10 bag size with the capacitive sensor placed in the center The Model 4431 incorpor
9. SHIELDED BAG TEST SYSTEM Model 4431 T Turnkey Voltage amp Energy System gt FA Ser RB i Ai o 4 be KC mle OCRE DN Ger a k PA a P a J ei y YA af H Wa r RK Ss ll Operating Manual 10 13 electro tech systems Inc www electrotechsystems com 3101 Mt Carmel Avenue Glenside PA 19038 Tel 215 887 2196 Fax 215 887 0131 IMPORTANT SAFETY INSTRUCTIONS Equipment containing HV The equipment described in this Manual is designed and manufactured to operate within defined design limits Any misuse may result in electric shock or fire To prevent the equipment from being damaged the following rules should be observed for installation use and maintenance Read the following safety instructions before operating the instrument Retain these instructions in a safe place for future reference POWER POWER CORD Use only the power cord specified for this equipment and certified for the country of use If the power mains plug is replaced follow the wiring connections specified for the country of use When installing or removing the power plug hold the plug not the cord The power cord provided is equipped with a 3 prong grounded plug a plug with a third grounding pin This is both a safety feature to avoid electrical shock and a requirement for correct equipment operation If the outlet to be used does not accommodate the 3 prong plug either change the outl
10. TS Model 4431 Shielded Bag Test System Scope Cal Date 07 17 2010 T Sys Cal Date 10 04 2010 i Test Data Sample 1 Sample 2 Discharge Peak Current m Energy Level nd Discharge Peak Current mA Energy Level nJ 4 24 40 2 94 4 23 20 2 61 2 24 06 2 96 2 22 80 2 66 3 24 00 2 96 3 22 80 2 62 4 24 40 2 94 4 22 40 2 64 5 24 00 2 98 5 22 40 2 57 6 24 00 2 96 6 23 20 2 64 Average 24 13 2 95 Average 22 80 2 62 Std Deviation 0 21 0 02 Std Deviation 0 36 0 03 sample 3 sample A Discharge Peak Current mA Energy Level ol Discharge Peak Current mA Energy Level nJ d 24 06 2 84 4 24 00 2 80 2 23 60 2 85 2 23 60 2 78 3 23 60 2 62 3 23 20 2 81 4 23 20 2 79 4 23 20 2 78 23 60 2 90 5 23 60 2 76 8 SS apa 6 23 20 2 74 EE 23 53 2 84 Average 224 A7 Std Deviation 8 HD o Deviation 0 33 0 03 Sample 5 Sample 6 Discharge Peak Current mA Energy Level nJ Discharge Peak Current m Energy Level nJ 4 26 80 3 16 d 23 20 2 73 2 26 40 3 21 2 22 40 2 66 3 26 00 3 08 3 23 20 2 69 A 26 00 3 12 4 22 40 2 70 5 26 00 3 11 5 23 20 2 72 6 26 00 3 11 8 22 80 2 73 Average 26 20 3 13 Average 22 87 2 70 Sid Deviation 0 33 0 04 Std Deviation 0 39 0 03 Data Analysis Average nd 2 84 Min nJ 2 57 Max nJ 3 21 Std Dev 0 17 electro tech systems inc 3101 Mt Carmel Avenue Glenside PA 19038 1 Figure 6 0 4 Energy Calculation Report 18 6 3 Product Testing per EIA 541 Voltage Differential 1 The following initial oscilloscope settings sh
11. and telephone number must be included in formal paperwork and enclosed with the instrument Round trip freight and related charges are the owner s responsibility NOTE ELECTRO TECH SYSTEMS INC WILL NOT ASSUME RESPONSIBILITY FOR ADDITIONAL COST OF REPAIR DUE TO DAMAGE INCURRED DURING SHIPMENT AS A RESULT OF POOR PACKAGING 23
12. ates adjustable stops to correctly locate 4 6 8 and 10 bag lengths For the standard size bag insert the two red plastic stops into the third hole from the front of the unit Insert a test bag by sliding it over the capacitive sensor until it hits the stops Center the bag latterly as shown in Figure 6 0 2 Be sure the sensor is inside the bag Figure 6 0 2 Test bag location lf testing manually set the FUNCTION switch to MAN nu Adjust the voltage for a reading of 1 000 10 Volts set the oscilloscope vertical sensitivity to 50mV div time base to 50nsec div and trigger level to 50mV Trigger mode is NORMAL Turn on the HV Initiate a discharge using either the front panel TEST switch or the foot switch The discharge pulse will activate for approximately 250 milliseconds The current pulse detected by the capacitive sensor will be displayed on the oscilloscope Typical waveforms for a static shielding bag are shown in Figure 6 0 3 Calliratian Discharge Ref 11 25 2 0 sample 1 n L3 Peak 462 mA mV i Test Date Time 1 0 Energy 50928 32 nd 07 21 1998 13 07 42 0 5 NN 100 of Wave Captured 0 0 Discharge 1 Discharge 2 Discharge 3 Paak 25 2 mA Energy 140486 Toi Peak 244 mA Energy 13 81994 mi Peak 25 2 mA Energy 13 34784 nd Discharge 4 l Discharge 6 Discharge 25 0 12 0 12 0 10 0 10 0 08 0 08 mV 0 06 mV 0 06 0 04 0 04 0 02 0 02 0 00 Jaen 0 00 lea Peak 24 4
13. d be as shown in Figure 5 0 4 The CH 1 and CH 2 Pk Pk readings should be exactly 10 0V as read on the scope MEASURE column If not adjust either the CH 1 and or CH 2 R pot on the rear panel until both channels read 10V This is equivalent to 1 000V because of the built in 100 1 voltage attenuators M Pos 400 0ns CH1 5 0064 CH2 S 00VBu Mi 2 50ms CH1 J 820 i MNov 12 03 52 Kallek Figure 5 0 4 Calibration waveforms After checking the Pk Pk calibration return the inverted CH 2 signal to the non invert mode Move the base line for both channels down to the first division on the screen This will increase the dynamic range of the measurement when testing actual bags 5 3 Testing EIA 541 Voltage Differential 1 Power up all instruments Allow at least 15 minutes to warm up 2 The following initial oscilloscope settings should be used Follow the manufacturer s instructions to implement a For normal bag testing set the scope VERTICAL sensitivities of CH 1 and CH 2 to 500mV This is equivalent to 50 Volts 100 1 attenuation NOTE The oscilloscope must have a nominal input impedance of 1 Megohm and 10 20 pF b Set the time base to 500 usec c Set the TRIGGER LEVEL to approximately 3 divisions to start If the scope fails to trigger then reduce it to 2 divisions If multiple triggers occur then increase it d Set the SINGLE SEQ button and initiate a discharge For a good shielding bag AV lt 30V t
14. ed discharge relay 4 Floating programmable capacitive sensor consisting of two 0 875 diameter precision ground stainless steel electrodes mounted in a 0 625 Delrin base with nominal capacitance of 6 pF Built in Tektronix CT 1 Current Transducer 100 1 Voltage Attenuators for voltage differential test Lever actuated stainless steel discharge and spring loaded ground electrodes 8 Discharge electrode grounding relay to remove residual charge between tests 9 Adjustable bag insertion stops for configuring the System for different bag sizes per specification oS 6 10 Calibration jumper Note 1 This cable no longer required 1 1 2 Oscilloscope 1 Tektronix Model TDS2022C 3 1 2 Computer 1 Running 32 bit Operating System Windows 2000 XP VISTA 7 3 1 3 Software 1 ETS Test Suit Manager Energy Calculation Program Version 4 0 3 3 4 0 Discharge Unit Description The Capacitive Sensor is a floating arm that contains the upper and lower electrodes CT 1 current transducer and 500 Ohm resistor Programming jacks located on both sides of the sensor arm allows the user to program the System for current or voltage measurements by inserting the pair of jumpers into the respective pair of 040 pin jacks as shown in Figure 4 0 1a and b nJ deltaV nd deltaV a SN Programming Jumpers Ka a Energy b Voltage Differential Figure 4 0 1 Capacitive sensor programming jumpers The adjustable power supply allows the user to make
15. et or use a grounding adapter FUSES Replace fuses only with those having the required current rating voltage and specified type such as normal blow time delay etc DO NOT use makeshift fuses or short the fuse holder This could cause a shock or fire hazard or severely damage the instrument POWER LINE VOLTAGE MAINS If the line mains voltage is changed or isolated by an autotransformer the common terminal must be connected to the ground earth terminal of the power source OPERATION CAUTION Equipment designed to simulate a high voltage electrostatic discharge such as the Series 900 ESD Simulators Model 4431 Shielded Bag Test System and the Model 4046 Static Decay Meter utilize voltages up to 30kV The basic nature of an ESD event will result in electromagnetic radiation in addition to the high level short duration current pulse Therefore personnel with a heart pacemaker must not operate the instrument or be in the vicinity while it is being used DO NOT OPERATE WITH COVERS OR PANELS REMOVED Voltages inside the Model 4431 can be as high as 2kV In addition equipment may contain capacitors up to 200pF charged to 1kV Capacitors can retain a charge even if the equipment is turned off DO NOT OPERATE WITH SUSPECTED EQUIPMENT FAILURES If any odor or smoke becomes apparent turn off the equipment and unplug it immediately Failure to do so may result in electrical shock fire or permanent damage to the equipment Contact the facto
16. ferences test methods in place in 1988 However ESD Association test standards developed since then are now specified The shielding effectiveness of the bag was previously evaluated using the voltage differential test method specified in EIA 541 However the energy test method specified in ANSI ESD 11 31 supersedes the voltage test and is now the specified test method MIL PRF 81705E and ANSI ESD 11 4 specify the ANSI ESD 11 31 test The ETS Model 4431 T Shielded Bag Test System meets the requirements of both test standards 2 0 TEST METHODS 2 1 ANSI ESD 11 31 ESD Association standard for evaluating the performance of electrostatic discharge shielding materials Bags This test method evaluates the performance of electrostatic discharge shielding bags The purpose of this standard is to ensure that testing laboratories using this test method to evaluate a given packaging material will obtain similar results This standard specifies the discharge waveform characteristics probe configuration probe capacitance and bag size Figure 2 0 1 shows the generic schematic of the test system Ri 10k 10M Bag Under Test ESD Simulator Nominally 100pF and 1 5k R2 500 Swi EE Current Probe Figure 2 0 1 System generic schematic Figure 2 0 2 shows the discharge current waveform requirement at the specified 1000 Volts when measured through a 500 Ohm resistor te 5 E per division
17. he computer program file select ETS select ETS Test Suite Manager Right click on Esd1131 rpt and select RENAME Change this file to Esd1131 Logo rpt Then right click on file Esd1131 NoLogo rpt Select RENAME Change file name to Esd1131 rpt 21 7 3 7 4 Installation lf the software has to be reinstalled or installed on another computer follow the installation instructions contained on the disc Customer Support For customer support contact ETS at 215 887 2196 or by e mail lt hient ets2 com 10 13 22 8 0 WARRANTY Electro Tech Systems Inc warrants its equipment accessories and parts of its manufacture to be and remain free from defects in material and workmanship for a period of one 1 year from date of invoice and will at the discretion of Seller either replace or repair without charge F O B Glenside similar equipment or a similar part to replace any equipment or part of its manufacture which within the above stated time is proved to have been defective at the time it was sold All equipment claimed defective must be returned properly identified to the Seller or presented to one of its agents for inspection This warranty only applies to equipment operated in accordance with Seller s operating instructions seller s warranty with respect to those parts of the equipment that are purchased from other manufacturers shall be subject only to that manufacturer s warranty The Seller s liability hereu
18. he waveform should look similar to that shown in Figure 5 0 5 If the signal levels of CH 1 and or CH 2 exceed the dynamic range of the scope sensitivity level selected this will cause the input amplifier to saturate causing a significant measurement error This condition normally occurs when buried metal layer bags are tested and 50 100 or 200 mV sensitivity levels are selected to obtain greater voltage differential resolution Mi Pos 1 4600 MATH Off Pk Pk CH1 Mone CH1 Mone CHI S00mYBy CH2 m M 500 5 ERLA 2 56 d ep 12 14 13 10Hz Figure 5 0 5 Typical AV for a good bag 12V If the bag is Bad AV gt 30V the waveforms will be similar to the one shown if Figure 5 0 6 To obtain the differential voltage manually subtract the CH 2 reading from the CH 1 reading CAUTION Do not use the MATH mode The waveforms contain high frequency noise The math can calculate the AV of the noise signal instead of the actual discharge signal causing erroneous AV readings M Pos 1 4600 MATH Off Pk Pk CH1 None 2 prera CH1 None CH1 S00mvEy CH2 S00mWEw M S00 us CH1 2 30 4 Sep le 14 22 lt 10H2 Figure5 0 6 Typical AV for a bad bag 206V Another anomaly that can be observed is the resolution of the calculation This is a function of the vertical scale setting At 5V div the resolution is 40mV 4V for each channel Since both channels are being looked at the same time the total resoluti
19. inter The Model 4431 utilizes a universal switching power supply and may be operated directly from 90 260 VAC 50 60 Hz line voltage mains with 0 5A resettable fuse that is reset by powering down the unit and after several seconds turning it back on The latest version of the ETS Energy Calculation Program is written for PCs running 32 bit Operating System Windows 2000 XP VISTA 7 This program controls the Model 4431 T the Tektronix TDS2022C oscilloscope used to capture the waveform and the computer to generate a report containing all the data specified in ANSI ESD 11 31 plus the verification and test data waveforms as shown in Figures 4 0 3 amp 4 SET UP Plug the AC line cord of the Model 4431 into a grounded outlet This is a standard IEC cord with North American grounded plug For non North American locations a line cord having the correct mains plug can be obtained from a local computer or electronics store Otherwise cut off the plug and install the appropriate plug for the location 5 1 ANSI ESD 11 31 Testing Energy Refer to Figure 5 0 1 for the System set up described below 5 2 Figure 5 0 1 System set up for Energy test Connect the BNC connector from the built in CT 1 current transducer into CH 1 of the oscilloscope The Terminator provided must be used in order to match the 50 Ohm output impedance of the CT 1 to the 1 MegOhm impedance of the scope Connect the 25 pin 9 pin cable to the USB 9
20. loaded in the supplied computer desktop or laptop However the software is also provided on disc with the System The supplied computer does not require a password If a password is desired install using standard computer password installation methods Make sure all cables are installed before opening the program 7 1 Running the ETS Test Suite Manager program To run the program proceed as follows 1 2 SE Ge 10 11 select ETS Test Suite Manager lf the computer is running Windows 7 a User Account Control window will pop up Click on Yes The program will open select Tests Enter all desired information Those fields in yellow are Default fields where information can be retained for subsequent testing select Start Test You will then be prompted on how to proceed When asked to Remove bag for calibration make sure the clamping lever is down before clicking Ok After running a test the prompt will ask Do you want to save data Review the waveforms to make sure all discharges are correct If not click No and rerun the test sequence on the bag To generate a report click on Reports then enter the Ref Archived reports can be brought up by entering the respective Ref 7 2 Removing ETS Logo at Bottom of Report To remove the ETS logo at the bottom of the report proceed as follows Oo NO Ole oN Close the program file Go to Programs in t
21. minor corrections to obtain the specified discharge current and energy A 3 2 digit LED readout displays the discharge voltage A switch on the front panel enables the user to turn off the high voltage when not in use Note Discharge switch will not work if high voltage is off Multicolored LED point sources indicate CHARGE and DISCHARGE The FUNCTION switch is used to select MANual operation of AV Voltage differential per EIA 541 using either 400 or 1 5 kKOhms and nJ Energy per ANSI ESD STM11 31 or AUTO nJ In the MAN mode the discharge pulse is initiated by either a front panel or a foot operated switch which is convenient when testing in a humidity chamber In the AUTO mode the discharge sequence specified in ANSI ESD 11 31 along with the scope settings are controlled automatically by the ETS Energy Calculation Program The discharge waveform generated by the Model 4431 meets the requirements of ANSI ESD 5 1 Electrostatic Discharge Testing Human Body Model A typical discharge waveform measured with the discharge electrode in direct contact with the Capacitive sensor is shown in Figure 4 0 2 E Ready M Pos 424 0ns Print PRINT Button Saves Ink Saver Layout Portrait File Format M 100ns CH1 Z 1 40 14 Jun 10 10 51 lt 10Hz Figure 4 0 2 Discharge waveform A spring loaded lever clamps the discharge electrode against the bag capacitive sensor and spring loaded ground electrode with approximately 5 pounds of force
22. mylar and the polyethylene film metal in or buried metal layer The metalized layer that provides the shield is usually aluminum or nickel with a thickness limited to approximately 100 Angstroms to maintain bag transparency Other constructions are available however that consist of carbon grids or conductive fibers such as carbon or copper Static Shielding is also provided by nontransparent bags that are either carbon loaded polyethylene or foil laminated such as the MIL PRF 81705E Type water vapor proof shielded bag In selecting the correct bag for a given application consideration must be given to whether the product being sensitive The ability of the bag not to charge the object inside and the ability of the bag to dissipate any charge on its surface in a timely manner when grounded must also be taken into account Various commercial and military specifications and test standards now exist for evaluating the different electrical and physical characteristics of the bag and or its material The static dissipative characteristics of the bag material is determined by measuring the surface resistance in accordance with Electrostatic Discharge Association test standard ANSI ESD 11 11 The antistatic ability to resist tribocharging characteristic is determined using procedures outlined in ESD ADV 11 21 The Electronics Industries Association Test Standard EIA 541 1988 Packaging Material Standards For The Protection Of ESD Sensitive Items re
23. nder is expressly limited to repairing or replacing any parts of the equipment manufactured by the manufacturer and found to have been defective The Seller shall not be liable for damage resulting or claimed to result from any cause whatsoever This warranty becomes null and void should the equipment or any part thereof be abused or modified by the customer of if used in any application other than that for which it was intended This warranty to replace or repair is the only warranty either expressed or implied or provided by law and is in lieu of all other warranties and the seller denies any other promise guarantee or warranty with respect to the equipment or accessories and in particular as to its or their suitability for the purposes of the buyer or its or their performance either quantitatively or qualitatively or as to the products which it may produce and the buyer is expected to expressly waive rights to any warranty other than that stated herein ETS must be notified before any equipment is returned for repair ETS will issue an RMA Return Material Authorization number for return of equipment Equipment should be shipped prepaid and insured in the original packaging If the Original packaging is not available the equipment must be packed in a sufficiently large box or boxes if applicable of double wall construction with substantial packing around all sides The RMA number description of the problem along with the contact name
24. on becomes 2x40mV or 80mV 8V At 1 amp 2V div the resolution of each channel is 20mV div 4V At gt 500mV div the resolution is 10mV div 2V and at lt 500mV div the resolution is 14 4mV div 0 8V The waveform shown for a good bag is at a scale setting of exactly 500mV div hence the AV resolution is 2V However the TEK 2222 scope has a variable vertical scale setting instead of a fixed scale setting The resolution can be increased by just setting the range scale of both channels to 490mV This will now give a total AV resolution of 0 8V This setting should work for both good and bad bags Also and this is very important If the scope TRIGGER LEVEL is set too low it is possible to get a double pulse caused by the recharging of the HBM capacitor What is then finally displayed on the screen may not be the initial discharge To eliminate this problem the single shot mode is recommended This button is located in the upper right hand corner and is labeled SINGLE SEQ Depress this button prior to initiating a discharge As far as bag testing is concerned to certify a bag 6 discharges are required To just check bags 1 3 discharges is satisfactory Also for very good bags the differential is very low This may result in CH 2 being the same or maybe read slightly higher than CH 1 This is within the tolerance of the measurement DO NOT expect to get the same exact reading with every discharge However the AV should be within a couple
25. ope will have already been calibrated If the scope is provided by the user it is first necessary to adjust the built in 100 1 attenuator amplitudes for equal amplitudes on each scope channel using the following procedure Place the shorting strap over the capacitive sensor to short the upper and lower capacitive sensor electrodes together The tape side contacts the DISCHARGE and GROUND electrodes Using the clamping lever secure the assembly as shown in Figure 5 0 3 Connect one end of a BNC cable to the CH 1 BNC connector on the rear panel of the Model 4431 and the other end to CH 1 of the oscilloscope Connect the other BNC cable to CH 2 of the Model 4431 and CH 2 of the scope Make sure the scope input impedance selector if so equipped is set to 1 Megohm Set the vertical scale setting of both channels to 5V div and the time base to 2 5msec Select the AUTO TRIGGER mode and adjust both CH 1 and Ch 2 base lines Invert the CH 2 signal choose the single shot mode For the Tek 2222 scope this is labeled SINGLE SEQ and is the button located in the upper right hand corner After superimposing the base lines return to the NORMAL TRIGGER mode H alo This cable no longer used Figure 5 0 3 Voltage calibration Test Set up Select the AV function on the Model 4431 front panel Adjust the voltage to exactly 1 000V and apply a discharge Both channels will receive the same 1 000V discharge The waveform obtained shoul
26. ould be used Follow the manufacturer s instructions to implement a For normal bag testing set the scope VERTICAL sensitivities of CH 1 and CH 2 to 500mV This is equivalent to 50 Volts 100 1 attenuation NOTE The oscilloscope must have a nominal input impedance of 1 megOhm and 10 20 pF b Set the time base to 500 usec c Set the TRIGGER LEVEL to approximately 3 divisions to start If the scope fails to trigger then reduce it to 2 divisions If multiple triggers occur then increase it d Set the SINGLE SEQ button and initiate a discharge For a good shielding bag AV lt 30V the waveform should look similar to that shown in Figure 5 0 5 If the signal levels of CH 1 and or CH 2 exceed the dynamic range of the scope sensitivity level selected this will cause the input amplifier to saturate causing a significant measurement error This condition normally occurs when buried metal layer bags are tested and 50 100 or 200 mV sensitivity levels are selected to obtain greater voltage differential resolution M Pos 1 460rms MEASURE CH1 Pk Fk 3 00 CHe Pk Pk 2 00 MATH Off Pk Pk CH1 None CHI None CH1 500mYBw CH2 S00mvBy M us CHITA 2 364 4 Sep le 14 13 lt 10Hz Figure 5 0 5 Typical AV for a good bag 12V lf the bag is Bad AV gt 30V the waveforms will be similar to the one shown if Figure 5 0 6 e To obtain the differential voltage manually subtract the CH 2 reading from
27. ry for further instructions DO NOT OPERATE IN WET DAMP CONDITIONS If water or other liquid penetrates the equipment unplug the power cord and contact the factory for further instructions Continuous use in this case may result in electrical shock fire or permanent damage to the equipment DO NOT OPERATE IN HIGH HUMIDITY Operating the equipment in high humidity conditions will cause deteriation in performance system failure or present a shock or fire hazard Contact the factory for further instructions DO NOT OPERATE IN AREAS WITH HEAVY DUST Operating the equipment in high dust conditions will cause deteriation in performance system failure or present a shock or fire hazard Contact the factory for further instructions DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE Operating the equipment in the presence of flammable gases or fumes constitutes a definite safety hazard For equipment designed to operate in such environments the proper safety devices must be used such as dry air or inert gas purge intrinsic safe barriers and or explosion proof enclosures DONOT USE IN ANY MANNER NOT SPECIFIED OR APPROVED BY THE MANUFACTURER Unapproved use may result in damage to the equipment or present an electrical shock or fire hazard MAINTENANCE and SERVICE CLEANING Keep surfaces clean and free from dust or other contaminants Such contaminants can have an adverse affect on system performance or result in electrical shock or fire To clean use
28. the CH 1 reading CAUTION Do not use the MATH mode The waveforms contain high frequency noise The math can calculate the AV of the noise signal instead of the actual discharge signal causing erroneous AV readings M Pos 1 460rms MEASURE CH1 Pk Fk BEI CH2 Pk Pk 840m MATH Off Pk Pk CH1 Mone pee CH1 Mone CH1 SUD CH2 S00mwBw M us CHI J 2 30 4 Sep le 14 22 lt 10Hz Figure5 0 6 Typical AV for a bad bag 206V Another anomaly that can be observed is the resolution of the calculation This is a function of the vertical scale setting At 5V div the resolution is 40mV 4V for each channel Since both channels are being looked at the same time the total resolution becomes 2x40mV or 80mV 8V At 1 amp 2V div the resolution of each channel is 20mV div 4V At gt 500mV div the resolution is 10mV div 2V and at lt 500mV div the resolution is 4mV div 0 8V The waveform shown for a good bag is at a scale setting of exactly 500mV div hence the AV resolution is 2V However the TEK 2222 scope has a variable vertical scale setting instead of a fixed scale setting The resolution can be increased by just setting the range scale of both channels to 490mV This will now give a total AV resolution of 0 8V This setting should work for both good and bad bags Also and this is very important If the scope TRIGGER LEVEL is set too low it is possible to get a double pulse caused by the recharging of the HBM capaci
29. tor What is then finally displayed on the screen may not be the initial discharge To eliminate this problem the single shot mode is recommended This button is located in the upper right hand corner and is labeled SINGLE SEQ Depress this button prior to initiating a discharge As far as bag testing is concerned to certify a bag 6 discharges are required To just check bags 1 3 discharges is satisfactory Also for very good bags the differential is very low This may result in CH 2 being the same or maybe read slightly higher than CH 1 This is within the tolerance of the measurement DO NOT expect to get the same exact reading with every discharge However the AV should be within a couple of volts as long as the bag does not deteriate The EIA 541 specifications for good and bad bags are totally different from the ANSI ESD 11 31 specification The energy and AV and not directly related to each other The AV of lt 30V is from MIL PRF 81705C The origin of this limit is unknown but was established over 20 years ago In addition the lt 30V AV is based on a 200pF 400k discharge network 20 This network is far less sensitive than the 100pF 1 5k network used for evaluating good bags Either network can be selected using the front panel switch For the energy test the limit specified in ESD20 20 for bags is currently lt 50nJ This may be reduced to lt 25nJ in the near future 7 0 SOFTWARE The ETS Test Suite Manager is pre
30. ufacturing and commercial applications It defines an acceptable bag as having lt 20nJ when tested in accordance with 11 31 2 3 MIL PRF 81705E This military standard defines the performance of Type 1 water vapor proof and Type 3 static shielding bags The acceptable energy limit when tested in accordance with 11 31 is lt 10nd 3 0 EQUIPMENT CONFIGURATIONS 3 1 Model 4431 T The ETS Model 4431 T Shielded Bag Test System is supplied with a laptop computer as shown in Figures 3 0 1 Figure 3 0 1 Model 4431 T Shielded Bag Test System This is a turnkey system that performs both the ANSI ESD 11 31 and the EIA 541 1998 shielding bag tests Depending on the test method selected the system provides the correct discharge current pulse for both the ANSI ESD 11 31 and EIA 541 tests The capacitive sensor detects the current pulse or the voltage differential and sends the signal s to the included oscilloscope for detection and from the oscilloscope to the included computer for processing and calculation of energy or attenuated voltage pulses from the direct connection to the 2 channel oscilloscope for the EIA 541 test The Model 4431 T Shielded Bag Test System consists of the following components 3 1 1 Discharge Unit 1 High voltage power supply with separate ON OFF switch adjustable from approximately 850 1 250 Volts with 3 2 digit LED display 2 Switched 100 amp 200 pF and 1 5 and 400kOhm discharge networks 3 Mercury wett
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