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The PCB Design Magazine, January 2014 Issue

1. sssese Next Level PCB cesses Prototron Circuits ssssse Sunstone Circuits sssssse ADVERTISER INDEX Next Month in s The PCB Design High speed 11 H welspdde dices sass 13 Desig n Torres What s the state of the art in high speed design And what exactly consti 31 tutes high speed in 2014 7 Find out in the February issue of The PCB Design Magazine when our expert M EU contributors discuss design on the bleeding edge And don t miss our featured The PCB List eere eene nen US Circuit creo reete Eee coverage of DesignCon 2014 See you next month January 2014 The PCB Design Magazine 69
2. The Absolute Best Value in High Technology S Printed Circuit Boards om Since 1971 Eagle Electronics Inc has provided our Customers with the highest quality Printed Circuit Boards at fair and competitive prices We are committed to exceeding our Customers expectations and requirements acheiving total customer satisfaction on each and every job It s just the way we do business A ee electr anics OF QUALITY PRINTED C MANUFACTURERS With Eagle you can expect Rapid Response to Quote Requests Fair and Competitive Pricing Costs 100 Quality Performance 100 On Time Delivery Performance Flexibility Scheduling Stock Consigned Inventory Programs Thorough follow up after job completion Total Satisfaction click here for more reasons why you should use eagle www eagie elec com NEW YEAR S RESOLUTION VALIDATE YOUR MODEL DATA continues ticular semiconductor vendor s simulator There are other types of models as well but these are the types that most users have to contend with Each type of model has its own unique char acteristics limitations and typical quality prob lems If you spend enough time working with a particular class of model you ll prob ably develop techniques for veri fying those models before use in system simulations Why should you care Well if you re using the re sults of system simulations to make design decisions you should care a lot
3. 1000 5000 10000 50000 100000 Number of Units Produced Figure 1 Quote generated cost comparison of rigid flex design vs rigid cable rigid PCB assembly This chart relies on simulated manufactur ing costs based on real PCB fab quotes for a four layer PCB with two inner flex layers in a rigid flex board The alternative rigid boards using flexible cable and connectors between them is also based on quotes from PCB fabricators In the latter case the calculation totals the costs of two separate four layer boards plus the costs of connectors and cable including assembly costs for both alternatives This calculated what if scenario does not take into account the im provements in reliability and overall higher product quality of the rigid flex circuit Among other reasons the individual boards with flex ible connectors and cable can form electrically cold joints causing malfunction By compari son the rigid flex circuit obviously eliminates these joints Surprisingly as soon as the project involves any volume over 100 units a rigid flex circuit design becomes the obvious choice Why Be cause rigid flex designs eliminate connectors connector assembly and increase reliability and process yields 28 The PCB Design Magazine January 2014 Until recently when a traditional PCB de signer first tackled a rigid flex design the avail able PCB design tools did not support board de sign in 3D Existing tools also
4. THE cb January 2014 2013 A Look Back by Steve Williams z The Wrap Up MAGAZINE by Ray Rasmussen gt I CONNECIOOZ Auk V 0 ne ast p e th list THE best way to find a PCB fabricator anywhere Candor Toronto Ontario Canada CAN Industries Website hl Videos Photos Contact Specs About Brochures News Candor Industries was created in 1999 to respond to 21st Century customers who need innovative solutions for complex technologies We foresaw the standard manufacturing methods possessed limitations to achieving this goal By inventing and developing certain technological advancements Candor put itself in the forefront as a solutions provider Markets Communication Computers Consumer Industrial Medical Military Aerospace Board Types Single sided Double sided Multilayer Flex Rigid Flex Mfg Volumes Prototype Small Medium Other Services Quick Turn Around R amp D Specialties 3D Features carbon contacts controlled depth drilling Cont Filled plugged vias Landless vial PC 6012 class 3 ISO 9001 ITAR rl A Hs compliant UL Click here to see a demo Why YOU should Showcase Capabilities listing for advanced search functionality Specialties and certifications listing Ability to upload brochures and videos Quick and easy Contact and RFQ buttons News web and contact links kto see a partial list of registered OEMs www the
5. d mA The Base for Innovation www isola up com i speed JANUARY 2014 THE pcb THE OPTIMUM VOLUME 3 MAGAZINE LI NUMBER 1 DEDICATED TO MAGAZINE thepcbdesignmagazine com PCB DESIGN 1 CONNECTE CONTENTS ARTICLES 26 An introduction to Rigid Flex Design Best Practices by Ben Jordan VIDEO INTERVIEWS 14 Dragon Circuits Old Company New Name and Ideas 42 Influence of Via Stub Length and Antipad Size on the 64 Blackfox Expands With Veteran Insertion Loss Profile Training Services by Alexander Ippich SHORTS COLUMNS 19 Graphene Sees 8 The Old Guard e the Light Moves On y by Andy Shaughnessy 33 Group Hopes to Produce Electricity On the Moon at Night 34 PDN Planning d and Capacitor gya nm Selection Part 2 QT 64 Pulse Laser by Barry Olney AP 3 Wins German ad gt Future Prize 2013 NEWS HIGHLIGHTS 20 PCB007 e EXTRAS 62 Mil Aero007 68 Events Calendar 66 PCBDesign007 y 69 Advertiser Index amp Masthead 6 The PCB Design Magazine January 2014 DESIGN FABRICATION fj ASSEMBLY A TEST M ALL UNDER i ONE ROOF We are a full turnkey shop that brings every part of the process together Our one company integrated solution results in better quality for your job and less hassle for you One purchase order results in one complete product The Integrated Solution sales murrietta com www murrietta c
6. There are a few positive signs looking for ward Leading indicators are rising in some re gions and new product designs are starting to show some life The overall world PCB produc tion is increasing 10096 growth over the past 18 The PCB Design Magazine January 2014 Apple plans to move 100 million of Macintosh computer manufacturing back to the U S While this may be a public relations move on Apple s part it is still 5100 million worth of work coming back 10 years which will continue to present more opportunities for the U S market Much of the talk at April s IPC APEX EXPO was how to bring manufacturing back to the U S Onshoring the preservation of exist ing manufacturing in America is increasing as a result of U S companies becoming more globally competitive through efforts such as Lean product design reduced labor cost through increased efficien cies and improved custom er responsiveness Reshoring the return of work to Amer ica that had been previously lost to offshore competition is also on the uptick China s rising labor costs political unrest and weaker exports are driving this trend Apple plans to move 100 million of Macintosh computer man ufacturing back to the U S While this may be a public relations move on Apple s part it is still 100 million worth of work coming back Smart Connected Devices I think there is a world market for maybe five computers Thomas Watson c
7. and entre preneurs have discovered our industry because of printed electronics and 3D printing They re going to rock our world They don t have the mindset we all have They re going to develop THE WRAP UP continues the systems to build the electronics of the fu ture not based on what we know with tradi tional PCBs but on PE and 3D platforms So for those of you who ve been wondering where all the young people are ask no more What will we see from the PE and 3D sec tors in 2014 No big gamechangers really Just lots more low cost prototyping systems In a re cent PCB assembly association survey printed electronics scored highest as the area of greatest interest for its members Just a couple years ago PE was hardly on anyone s radar The link below is an example of the kinds of efforts being made by GenZ get it Z axis third dimension of circuit manufacturers Circuit printing startup reaches 30 day kick starter fundraising goal in 5 hours And to help us get a glimpse of the kind of energy going into this Oak Ridge National Lab is giving 35 000 3D printers to U S schools Again the lack of young people in our industry won t be an issue for long It s just not going to be the industry we re used to Read more about this initiative here Tremendous opportunity awaits all those who grab it and 2014 holds a lot of promise for our industry You have to open your eyes though to see it I ll leave you with a few fa
8. engineer from quote to delivery We lead the industry with an on time delivery rate of over 99 Plus our on site technical support is available every day of the year 24 7 365 giving Sunstone unparalleled customer service Get a quote instantly at Sunstone com Live customer support 24 7 365 Online quote amp order RoHS compliant finishes Over 99 on time delivery Free 25 point design review Free shipping amp no NREs Best overall quality amp value in industry RF exotic materials PCB123 design software In business for over 40 years Flex Rigid Flex boards Controlled impedance testing YEARS SUNSTONE 40 Years of Serving You Questions Sunstone Technical Support is always open 1 800 228 8198 support sunstone com feature column THE WAY SEE IT The Wrap Up by Ray Rasmussen PUBLISHER I CONNECTOO7 Good Riddance Tying up 2013 into a nice tight bow tossing it over my shoulder and then dusting off my hands comes to mind when trying to wrap up the year I didn t much like the year that was Politics seemed to take center stage for most of us as those we elected to keep us on track did nothing to improve the economy A few changes should be noted On the PCB side of things we lost Endicott Intercon nect Technologies to bankruptcy and in August Hitachi Via Mechanics sold to the Longreach Group Hitachi has claimed the global top spot over the last decade filling Chinese factories with their drilling
9. 08 diff 09 diff 10 Analysis of Variance for 5GHz using Adjusted SS for Tests Source DF Seq SS Adj SS Adj MS F P panel 4 0 2908 0 0467 0 0117 0 48 0 753 antipad size 1 1 4273 1 8685 1 8685 76 33 0 000 diff 9 36 7577 36 7577 4 0842 166 83 0 000 Error 72 1 7627 1 7627 0 0245 Total 86 40 2385 S 0 156465 R Sq 95 62 R Sq adj 94 77 Q panel accounts for 0 7 of the variation gt minor influence OQ antipad size accounts for 3 5 of the variation gt second order influence Q stub length accounts for 91 3 of the variation gt major influence Figure 27 ANOVA general linear model for differential insertion loss at 5 GHz SE 02 SE 04 SE 06 SE 08 SE 10 Figure 28 Cross sections of via stubs 60 The PCB Design Magazine January 2014 article INFLUENCE OF VIA STUB LENGTH AND ANTIPAD SIZE ON THE INSERTION LOSS PROFILE continues Fitted Line Plot F S 0 952826 R Sq 99 995 R Sq adj 99 996 E E D gt 2 E 2 sc 3 t Lj B A T d T T T T A B c D E F nominal stub Figure 29 Fitted line plot for actual versus nominal stub length all to SE10 the maximum stub length The measured stub length was plotted against the nominal stub length Figure 29 Obviously actual stub lengths and target stub lengths correlate tightly This can be considered as proof that the backdrilling operation was well under control Summary
10. ANOVA main effect plots for 5 GHz and 10 GHz are shown in Figure 19 and Figure 20 Using the numeric output of the ANOVA at 5 GHz frequency chosen as one example shows the panel to be a minor influence caus ing only 1 896 of the variation The antipad size is a second order influence with an effect of 11 396 and the stub length is again the major influence being the cause of 83 296 of the varia tion as shown in Figure 21 Differential Insertion Loss Testing The setup for the differential insertion loss testing can be found in Figure 22 A 4 port vector network analyzer was calibrated at the connector interface to the device under test with an elec tronic calibration module The use of the eCal module lead to a significantly faster easier and virtually error proof calibration process especial ly for the 4 port calibration On the test board the interface to the VNA was provided with flange mounted compression type connectors Figure 23 shows a screenshot of two differ ent stub lengths superimposed The upper por Main Effects Plotfor 10GHz Data Means panel PCB 104 e j 454 20 25 g 30 T T d T T T g i 2 3 4 5 1 2 6 7 antipad SE ee 10 LL 15 20 254 30 T T EEUU IUE EI 50 60 80 90 01 02 03 04 05 06 07 08 O9 10 Figure 20 Main effect plot for insertion loss at 10 GHz January 2014 The PCB Design Magazine 55 INFLUENCE OF
11. In this investigation data were generated to predict the additional insertion loss generated by via stubs of the launch vias The effect on the frequency of the resonant notch in the loss profile was also demonstrated Both parameters were evaluated over various stub lengths and antipad sizes The data confirmed that a larger via stub re duces the resonant frequency and increases the overall insertion loss It was also demonstrated that a smaller antipad size has the same effect but to a much smaller degree PCBDESIGN References 1 Ippich A A Designed Experiment for the Influence of Copper Foils and Oxide Replace ments on Impedance DC Line Resistance and Insertion Loss IPC APEX Expo 2011 2 Ippich A A Designed Experiment for the Influence of Copper Foils on Impedance DC Line Resistance and Insertion Loss IPC APEX Expo 2012 3 Bogatin E Practical Analysis of Back plane Vias DesignCon 2009 4 Perez Wilson M The M PCpS Methodol ogy Stage IV Optimization ISBN 1 883237 05 X 5 Perez Wilson M AnovA Analysis of Variance ISBN 1 883237 14 9 6 Agilent User Manual N52424A User s and Service Guide N5242 90008 Alexander Ippich is a senior signal integrity engineer at Multek Previously he held various positions in Applica tion Engineering and R amp D He worked also in the develop ment of thin film TFT matrixes and LCD displays His PCB manufacturing and engi
12. NEW YEAR S RESOLUTION VALIDATE YOUR MODEL DATA continues based on conversations with customers it s not terribly popular either So why do I keep going on about it Because it s important and because I ve been burned too many times In my former job the scenario would repeat itself We d put together a project schedule that was too aggres sive to begin with and then the models would show up late Instead of running the tests we planned we d run quick tests to make up time and the models would look good they always looked good at first Then we d use them for a week or two before we noticed some discrepancy in simulation results trace it back and realize the model had been bad all along The scenario re peated itself so many times that we finally com piled a list of all the ways we had been burned defined an incoming model inspection process and stuck to it It didn t solve all our problems but things did get better If this were a sales pitch I would pull out the magic answer to the problems I ve posed Do you have problem SI models that are dif ficult to test No problem Try new SI TestAll with Borax Your simulation models have never been so fast and so clean Of course that s the exact opposite of what I m trying to say I m saying that we as design ers need to do the hard work of understand ing whether we can trust our models before we start using them to make design decisions That message isn t g
13. SEO7 is barely acceptable in this example whereas all shorter stub lengths pass the requirement Fig ure 14 Beside evaluating the magnitude of inser tion loss the return loss was also plotted Fig ure 15 Obviously the effect of stub length and 52 The PCB Design Magazine January 2014 Figure 12 Average data for S21 magnitude increas ertion loss due to via stub antipad size is much less pronounced than in the insertion loss charts Because of the wide maxima at the resonance frequency in the return loss chart no numerical evaluation was performed here However plot ting the insertion loss and the return loss in one chart confirmed the expected alignment of the dips in insertion loss IL and maxima in return loss RL regarding frequency which is shown in Figure 16 for the longer stubs The charts provided a good overview about the influence of the stub length and the antipad sizes but to get quantitative data on the level of influence ANOVA evaluations were performed The first ANOVA shows the influence of the pa article INFLUENCE OF VIA STUB LENGTH AND ANTIPAD SIZE ON THE INSERTION LOSS PROFILE continues Figure 15 Averages for single ended return loss Figure 16 Alignment insertion loss and return loss Main Effects Plot for resonant frequency Data Means antipad size stub length Mean N N w UJ ao A NEC a e RN C T T T T T T T 50mil 60mil 80ril 90mi SEO04 SEO5 S
14. SRF at the anti resonant peak 3 Add more ESR by increasing the number of capacitors 4 Increase the capacitance of the planes by using thinner plane to plane dielectrics The resonant and anti resonant peaks of the bypass and decoupling capacitors have now been taken into account but we also need to deal with the plane resonance Ideally the planes a perfect lumped element capacitor of this size should provide a very low impedance between power and ground at very high frequencies sev eral hundred MHz and higher But planes left open at the edges behave like wide un terminat ed traces from a signal integrity point of view beyond design PDN PLANNING AND CAPACITOR SELECTION PART 2 continues reflecting at the ends creating resonances in the transmission line As the frequency increases to half wavelength the series resonance builds up a standing wave pattern reflecting from the open edges of the plane Fortunately this hap pens above 1GHz Also the mounting inductance of each ca pacitor needs to be taken into account The mounting inductance is comprised of three components Capacitor footprint and fanout capacitor height above or below the plane and power plane spreading inductance These three elements describe the loop in which current must flow the bigger the loop the more the in ductance The footprint land pattern for a ca pacitor dominates the total ESL It consists of via placement with respect to t
15. an engi neering program because of her gender Brill earned a mathematics degree instead gradu ating at the top of her class Brill worked for Douglas Aircraft RCA Astro Electronics and NASA and took home a slew of honors Presi dent Obama presented her with the National Medal of Technology and Innovation in 2011 Yes the old guard people who made huge disruptive contributions to technology are slowly moving on But the innovation contin ues and we re all a part of it in one way or an other That s the great thing about the electron ics industry It s Show Time It s that time again We ll be bringing you Real Time with video coverage of the indus try s hottest trade shows starting with Design Con January 29 30 2014 at the Santa Clara Convention Center The exhibition has been moved back one day so the show runs Wednes day and Thursday instead of the usual Tuesday and Wednesday Then we move on to the CPCA Show in Shanghai March 18 20 followed almost im mediately by IPC APEX EXPO March 25 27 at Mandalay Bay in Las Vegas Who needs sleep It s an exciting time and we hope to see you on the road Happy New Year PCBDESIGN Andy Shaughnessy is manag ing editor of The PCB Design Magazine He has been cover ing PCB design for 13 years He can be reached by clicking here January 2014 The PCB Design Magazine 9 ce VY New Year s Resolution Validate Your Model Data by Todd Westerhoff SI
16. ed appearing with this magical button marked Dolby and that was the beginning of true high fidelity at least in my mind I remember looking at my new Panasonic cassette turntable stereo and thinking When would I ever not want to use the Dolby button Why not just build Dolby into the system The first generation of Dolby wasn t perfect it cut out some of the middle and treble frequencies But it allowed us to turn the music up louder than we ever could before and for that we au diophiles owe Ray Dolby a great debt Eiji Toyoda the creator of the Toyota Way passed away at 100 He joined his uncle s car company and pioneered the development of Lean manufacturing kaizen kanban zero defects and a host of other production con cepts used by PCB assemblers today Toyoda had an uncanny ability to spot inefficiencies in any type of operation and he prodded his engineers to study W Edwards Deming so they THE OLD GUARD MOVES ON continues could learn to increase productivity and qual ity He also pushed Toyota to start manufactur ing cars overseas and to enter the luxury car market And Yvonne Brill creator of a variety of in novations in rocket propulsion died at 88 Pos sibly the only woman working as a rocket sci entist in the 1940s she holds a patent for her electrothermal hydrazine thruster EHT which to this day helps keep communications satel lites in geosynchronous orbit When she was denied entry into
17. equipment The reliance on that low margin sector even though they sold 22 The PCB Design Magazine January 2014 a ton of machines may have cost them their business TTM COO Shane Whiteside left the compa ny to pursue other opportunities and a few months later his boss Kent Alder retired Those two built one of the world s largest PCB compa nies but it makes you wonder Their departures were so close together it almost feels like they were jumping ship although there aren t any indications that there s anything wrong with the company The stock is doing fine But it makes you think Other notable M amp A activity includes Kyo cera buying NEC Toppan Circuit Solutions Graphic Plc buying Calflex Elga Europe enter ing into a joint venture with Eternal Chemical K Ww GET YOUR PRODUCTS TO MARKET FASTER When it comes to looking for a competitive advantage your PCB design strategy can ultimately prove to be your secret weapon as you move into an uncertain future Are you providing your design teams with access to the right technology to make that happen Speed time to market today with the PCB technology of tomorrow LET US SHOW YOU HOW VIRTUAL DESIGN FLOW DESIGN THROUGH PROTOTYPING CONCURRENCY MANUFACTURING Follow us gt THE WRAP UP continues Eltek joining with Nistec an Israeli EMS pro vider R amp D Circuits acquiring PCB design com pany Altanova EPEC and Suncoast Digital join ing
18. forces EPEC also purchased UPE back in January to enhance its extreme copper technol ogy China s Fastprint picked up eXception s PCB business SMG and Global Circuits merged operations Yash Sutariya s management team purchased Alpha Circuit Corp Zutron acquired Teknoflex andAll Flex started off the year ac quiring Tri C Design On the EMS side of things CirTran finally got out of the EMS business and is now putting all of their focus on beverages I have not spent time figuring out how and why they made the switch from electronics manufac turing to playboy energy drinks Not a big loss I guess CTS also left the industry selling its EMS capabilities to Bench mark Electronics so that they could focus on their sensors and components business I guess focus is good Hunter Technology acquired NBS s design assets Natel bought EPIC Technologies while as sembly equipment supplier Essemtec sold its operations to a private investor group As one gentleman from Raytheon said at the recent tin whiskers conference they haven t seen any increase in failures due to whiskers but he also acknowledged the most attention Those they are spending a ton Moving On China s been sucking wind most of the year Seems like things are improving but it s any body s guess China s official numbers are sus pect at best Europe is finally coming out of recession which is good but it will take some time for things to get moving
19. result in unusual in termittent signal integrity issues including high crosstalk and excessive emission of radiation The integrity of the PCB stackup and the PDN are the basis for a stable product Decoupling is not the process of placing a capacitor adjacent to the IC but rather it is the process of placing an L C network adjacent to the IC to supply the high transient switching current Decoupling capacitors supply instanta neous current at different frequencies to the drivers until the power supply can respond For bulk decoupling at the supply level 38 The PCB Design Magazine January 2014 Figure 6 One value capacitor per decade approach including VRM loop inductance and plane capaci tantalum is usually preferred due to the avail ability of high capacitance ratings Large capacitance value ceramics provide effective decoupling at about 2596 of the nomi nal capacitance value compared to standard tan talums The capacitance of a capacitor is deter mined by three factors The number of layers in the part the dielectric constant and the active area The dielectric thickness is inversely related to the capacitance so the thicker the dielectric the lower the capacitance value The rating compared to working voltage for multilayer ceramic capacitors is 2 1 The dielectric constant depends on the ce ramic material used NPO has the lowest dielec tric constant followed by X7R and YSV
20. 08 0660 barb iconnect007 com MARKETING SERVICES TOBEY MARSICOVETERE 916 266 9160 tobey iconnect007 com EDITORIAL GROUP EDITORIAL DIRECTOR RAY RASMUSSEN 916 337 4402 ray iconnect007 com MANAGING EDITOR ANDY SHAUGHNESSY 404 806 0508 andy iconnect007 com TECHNICAL EDITOR PETE STARKEY 44 0 1455 293333 pete iconnect007 com MAGAZINE PRODUCTION CREW PRODUCTION MANAGEI mike iconnect007 com MAGAZINE LAYOUT RON MEOGROSSI AD DESIGN SHELLY STEIN MIKE RADOGNA INNOVATIVE TECHNOLOGY BRYSON MATTIES COVER ART SHELLY STEIN ncb The PCB Design Magazine is published by BR Publishing Inc PO Box 50 Seaside OR 97138 2014 BR Publishing Inc does not assume and hereby disclaims any liability to any person for loss J S IN or damage caused by errors or omissions in the material contained within this publication regardless MAGAZINE of whether such errors or omissions are caused accidentally from negligence or any other cause January 2014 Volume 3 Number 1 The PCB Design Magazine is published monthly by BR Publishing Inc Dymax Mentor Graphics SHAX Engineering Candor Industries ne 47 Magazine Downstream Technologies Dragon Circuits csse Eagle Electronics ss Electrol be ec ect necne Multilayer Technology eene Murrietta Circuits
21. 4 will be held September 9 11 2014 in Santa Clara California The event includes a three day technical conference and one day ex hibition to be held at the Santa Clara Convention Center IEEE Stakeholders Want Standards based Interoper ability amp Communications Every year tens of billions of dollars reportedly slip through the cracks in interoperability and connec tivity among medical devices in the United States alone But now there seems to be interest in clos ing those gaps in the global web of healthcare says the IEEE Standards Association PCBDesign007 com for the latest circuit design news anywhere anytime EMA s Simulation Team Welcomes Mike Rogers Mike brings a wealth of injection molding experi ence to our team enabling him to support our Au todesk customers with his application knowledge and expertise said Manny Marcano president and CEO His experience rounds out our simu lation competencies allowing us to cover the full Autodesk mechanical simulation product line DesignCon Introduces Keynote Speakers amp New Tech Director The 2014 DesignCon program which comprises the largest educational conference and technolo gy exhibition for chip board and systems design engineers in the high speed communications and semiconductor communities will provide attend ees with an array of in depth technical education and training opportunities Nakahara s Japanese PCB Industry Update T
22. A prototype board run for a high end sys tem can cost 100 000 plus the time it takes to get assem bled boards back and running in the lab Bad design deci sions that result from poor models can delay a product s ship date by months and the lost sales could probably pay off your house So model quality matters but the real question is whether users are in a position to do anything about it or not For example let s look at S parameter models which are useful for all sorts of ap plications In practice there are limits as to how accurate most S parameter models are Since they are frequency based models they should specify how en ergy is transferred all the way down to 0 Hz or DC S parameters can be created either analyti cally often through the use of 3 D field solver software or empirically derived from measure ment Both techniques often have trouble gen erating the DC portion of the S parameter file accurately Why does it matter It matters be cause many simulators perform a steady state DC operating point solution before beginning transient waveform analysis If the DC char acteristics of the circuit are off the operating point will be off and the quality of the tran sient analysis may be compromised as a result 12 The PCB Design Magazine January 2014 A prototype board run for a high end system can cost 100 000 plus the time it takes to get assembled boards back and running in the lab B
23. ANTIPAD SIZE ON THE INSERTION LOSS PROFILE continues plated through holes via stub backdrill Figure 1 Backdrill principle Best performance would be reached with a sig nal path without distortion and zero attenu ation In the imperfect reality the insertion loss of the transmitting structures needs to be as small as possible and should not show large non linearities For insertion loss reduction the dielectric loss needs to be minimized by using low Df ma terials The second important parameter is the copper loss which is influenced significantly by the roughness of the signal trace The applica tion of both adequate oxide replacement and copper foil quality is key However there is another element in the transmission channel that needs to be evaluat ed The via structure connecting the integrated circuit or connectors to the traces on the inner layers of the printed circuit board has a huge negative impact on the insertion loss profile es pecially if the via extends significantly beyond the layer that needs to be electrically connected As discussed in Eric Bogatin s Practical Anal ysis of Backplane Vias the via stub creates a large notch in the insertion loss profile at the quarter wave frequency A commonly used method to reduce the via stub is to backdrill A second drilling step after electroplating of the through holes removes the copper in the un used portion of the via Figure 1 Since
24. Dissipation Factor Df is the percentage of energy wasted as heat in the capacitor While X2Y MLCCS offer superior perfor mance and space wise they are about five times the price of standard 0402 DYMAX CONFORMAL COATINGS BETTER PROTECTION AND HIGHER THROUGHPUT BEYOND A SHADOW OF A DOUBT Dymax Conformal Coatings cure in seconds with UV light and with ambient moisture curing available for shadowed areas you can be confident you re getting maximum protection even underneath components Add vivid blue fluorescing for easy inspection of coating coverage and you ll see more throughput in less time using less floor space All with unsurpassed protection against moisture dust chemicals and temperature cycling And they re backed by the Dymax Edge an integrated offering of oligomers customized adhesives and coatings cure and dispense equipment and application expertise that enables Dymax to deliver the best solution to the customer Visit dymax com conformalcoating to download the new Guide to Light Cure Conformal Coatings cy 877 396 2988 SDYMAX DYMAX COM beyond design PDN PLANNING AND CAPACITOR SELECTION PART 2 continues Impedance 0 unciam Frequency Hz Tepedance Q OR Frequency Hz p Figure 7 Target frequency and optimized value approaches including VRM loop inductance and plane capacitance of 3M ECM A capacitor s equivalent circuit is basically a series capacito
25. EO6 SEO7 SE08 SEO9 SE10 Figure 17 ANOVA chart for resonance frequency rameters stub length and antipad size on the cy slightly The main driver however is the stub resonance frequency Figure 17 length with the short stub length SE04 result The main effect plot demonstrates that ing in a resonance at close to 40 GHz whereas larger antipad sizes increase resonance frequen the longest stub SE10 creates a resonance only January 2014 The PCB Design Magazine 53 article INFLUENCE OF VIA STUB LENGTH AND ANTIPAD SIZE ON THE INSERTION LOSS PROFILE continues General Linear Model resonant frequen versus antipad size stub length Factor Type Levels Values antipad size fixed 4 50mil 60mil 80mil 90mil stub length fixed 7 SE04 SE05 SE06 SE07 SEO8 SEO9 SE10 Analysis of Variance for resonant frequency using Adjusted SS for Tests Source DF Seq SS Adj SS Adj MS F P antipad size 3 3 83060E 19 1 42535E 18 4 75118E 17 0 84 0 492 stub length 6 2 26578E 21 2 26578E 21 3 77629E 20 666 95 0 000 Error 16 9 05929E 18 9 05929E 18 5 66205E 17 Total 25 2 31314E 21 S 752466163 R Sq 99 61 R Sq adj 99 39 O antipad size accounts for 1 7 of the variation gt minor influence Q stub length accounts for 98 of the variation gt major influence less than 0 5 in the error term Figure 18 ANOVA general linear model for resonance frequency Main Effects Plot for 5GHz Data Means p
26. Investigation During a routine measurement of insertion loss over frequency on a 0 220 board Figure 2 significant differences were found depend ing on the measured layer Testing the same lay ers with backdrilled vias eliminated the differ ences and resulted in a straight insertion loss curve without the deep resonances Figure 3 This finding initiated a thoroughly investiga tion into the influence of via stubs on electrical performance The Test Vehicle An 8 layer stackup was used for the test ve hicle with one offset stripline on layer 3 refer encing to ground layers 2 and 4 Layer 6 was an unused layer and layers 5 and 7 were also ground layers The outer layers provided the landing patterns for probing The probing was performed from the top side which in turn generated maximum via stubs for the layer 3 features A mid loss material has been applied for the DOE as many designs in the range of 3 125 10Gbs are using them Similar glass styles and thicknesses were used for the cores and prepregs to get a relatively balanced stripline design A rather wide line width in combina tion with 1 oz copper delivered minimum DC resistance Together with a smooth copper foil these design attributes were resulting in a relatively small insertion loss The complete stackup de tails can be found in Figure 4 The design consisted of single ended and differential transmission lines on layer 3 with a via connecting the li
27. It s been a wild year in the PCB design community Naturally the top PCBDesign007 columns of 2013 cover a maze of topics from delamination to rout ing techniques So without further ado here are the Top 10 most read PCBDesign007 columns of the past year 66 The PCB Design Magazine January 2014 Mentor s Capital Tool Adds 1000D Compliance The Capital suite addresses vehicle electrical sys tem definition design manufacture and service 1000D support is one of over 60 new capabili ties available in the latest version Users can au tomatically generate 1000D compliant informa tion packages directly from their electrical design data using the Capital Publisher tool reducing the costs and lead times associated with documenta tion creation CAM Engineering Easier with Ucamco s Integr8tor 8 2 Ucamco is delighted to announce its release of Integr8tor 8 2 This is the latest generation of a unique suite of tools that support the CAD to CAM data transfer process as well as pre CAM and CAM functions in PCB manufacture IPC Releases New Document Pricing Structure On January 12 2014 IPC will implement a new simplified pricing structure for standards and tech nical documents The new pricing structure is based on the complexity of the document num ber of pages number of images and color with three distinct pricing levels PCB West 2014 Dates Announced UP Media Group Inc has announced the annu al PCB West 201
28. January 2014 The PCB Design Magazine 49 article INFLUENCE OF VIA STUB LENGTH AND ANTIPAD SIZE ON THE INSERTION LOSS PROFILE continues average 47 56 48 23 37 19 stds 087 081 091 min 45 80 47 12 96 09 max 4847 49 89 98 41 pk 088 133 268 Target 30 00 50 00 100 0000 lower spec limit 46 00 45 00 30 00 upper spec limit 55 00 55 00 110 00 tool date time parts serial workorder datecode sig3 8 25mil_ sig6 8 25mil sig3 7 25mil Pola 47202012 2141 SCBACKDR TV 1 720449 1 1612 48 28 49 89 9748 Polar3 4 20 2012 2144 _S BACKOR TV 2 720449 1 1612 46 89 47 75 97 75 Polar 4 20 2012 _ 21 44 S BACKDR IV 3 720449 1 1612 45 80 48 94 97 93 Polars 4 20 2012 2143 S BACKOR TV 4 720449 1 1612 4681 48 44 98 41 Pola 4 202012 2143 S BACKDR TV 5 720449 1 1612 4847 4712 3839 Polad 572 2012 1252 SEBACKDRIV 7205131 2012 48 06 475 3621 Polar Polars 6 22 2012 12 64 S BACKDR1V Polar 5 22 2012 1255 S BACKDR TV Pola 5 22 2012 1255 S BACKDRIV Table 1 Impedance results 720513 1 47 30 47 64 7205131 2012 48 46 48 60 96 72 720513 1 2012 48 00 48 44 9623 72051331 2012 47 52 4800 9645 eye e lo Agilent N5422A PNA X 4 port network analyzer Agilent N4692 electronic calibration module cable UFA 147A 2 92mm connectors Molex compression mount connectors Full 2 po
29. SOFT SUMMARY As we begin 2014 remember Sig nal integrity simulations are only as good as the models that go into them But how thoroughly do we really validate simulation models before we use them Sure you ll have plenty to worry about in the upcoming year But here s an idea to con sider that might save you some time and money in 2014 Do you test and correlate simulation models or do you just take someone else s word for it When we do take someone else s word for it is there written evidence of that testing and correlation and do we take the time to review 10 The PCB Design Magazine January 2014 it Let S be honest we all want fast accurate simulation models with plug and play simplic ity Testing simulation models is difficult time consuming and a general pain in the neck We know that if we really take a close look at most of the models we use we ll likely raise questions that take time to resolve time that most of us don t have in our project schedules There are two types of models involved in SI simulation interconnect and semiconductor models Interconnect models include transmis sion lines vias connectors and passive compo nents They may be represented in the simu lation as individual elements or they may be combined together and provided as S parameter data Semiconductor SI models can be a type of SPICE there are multiple variants IBIS IBIS AMI or a model that is designed to run in a par
30. Technology amp Innovation NASA and the Commonwealth Center for Ad vanced Manufacturing CCAM in Richmond Vir ginia have joined forces to advance technology and innovation U S Aviation Industry Poised to Enter Second Golden Age Emerging foreign competitors are ramping up their capabilities and technological advancements in their home markets and are even expanding their manufacturing footprint here in the U S in ways that will likely alter the industry s competi tive landscape through this decade and beyond said Scott Thompson PwC s U S aerospace and defense leader IDtechEx Electrics Will Be the Hire a Veteran Month Last month Denver s 9News featured a segment with Andrew Stone of Lockheed Martin discussing his company s plan to hire nearly 180 veterans for high tech positions in assembly during Hire a Vet eran Month ESCATEC is Founding Member of Swiss Future of UAVs The total market value for electric unmanned aeri al vehicles UAVs will reach over one billion dollars by 2023 according to findings in the new IDTe chEx report Electric Unmanned Aerial Vehicles UAV 2013 2023 Total Avionics Sales to Exceed Photonics Group Being a founding member of this SWISSMEN pro fessional group for the Photonics industry puts ESCATEC in a very good position to support this growing industry in Switzerland with ESCATEC s outstanding knowledge and experience in re search design and devel
31. VIA STUB LENGTH AND ANTIPAD SIZE ON THE INSERTION LOSS PROFILE continues General Linear Model 5GHz versus panel antipad SE Factor Type Levels Values panel fixed nO 2 9 PARES antipad fixed 4 50 60 80 90 SE fixed 10 01 02 03 04 05 06 07 08 09 10 Analysis of Variance for 5GHz using Adjusted SS for Tests Source DF Seq SS Adj SS Adj MS F P panel 4 0 4770 0 0701 0 0175 5 41 0 000 antipad 3 3 0815 0 8301 0 2767 85 45 0 000 SE 9 22 6476 22 6476 2 5164 777 07 0 000 Error 316 1 0233 1 0233 0 0032 Total 332 27 2293 S 0 0569063 R Sq 96 24 R Sq adj 96 05 O panel accounts for 1 8 of the variation gt minor influence O antipad size accounts for 11 3 of the variation gt second order influence stub length accounts for 83 2 of the variation gt major influence Figure 21 ANOVA general linear model for insertion loss at 5 GHz Agilent N5422A PNA X 4 port network analyzer 2 Agilent N4692 electronic calibration module 2 cable UFA 147A 2 92mm connectors L Molex compression mount connectors Figure 22 Differential insertion loss setup 56 The PCB Design Magazine January 2014 INFLUENCE OF VIA STUB LENGTH AND ANTIPAD SIZE ON THE INSERTION LOSS PROFILE continues File Trace Chan Trace 1 Response Marker Analysis Stimulus Utility Help Hold CH Sdd21 amp Mem C 4 Port Scale Per Division ENES Reference Level Reference Position Ele
32. acked together had the best chance of matching ITO s perfor mance Graphene has one key advantage over ITO it allows more than 97 of light to pass through to the solar cell beneath regardless of its wave length In contrast ITO tends to block certain wavelengths more than others With the refinement in the graphene manu facturing process it would be possible for the sheet resistance of graphene to be an order of magnitude lower than the current state of the art says Koh This would allow just one or two sheets of graphene to beat ITO on both conductiv ity and transparency making graphene transparent elec trodes much more widely applicable January 2014 The PCB Design Magazine 19 PCB007 News Highlights IPC October PCB Sales Orders Up Book to Bill Dips Although both sales and order growth are trend ing up compared to last year sales have outpaced orders in the past three months causing the book to bill ratio to dip said Sharon Starr IPC s direc tor of market research Year on year sales growth has been improving for the past six consecutive months and finally turned positive in October Viasystems Opens World class Factory in California Designed to consolidate the sprawl of 13 build ings that used to represent DDi s PCB business the new factory is housed in an ex MFLEX site and was constructed from scratch This enables the com pany to service its very high end custome
33. acts the insertion loss profile To optimize the via the stub length needs to be re duced by methods like backdrilling the copper out of the unused portion of the PTH In this article the influence of remaining stub lengths varying between a couple of mils and 100 mils on the insertion loss profile is 42 The PCB Design Magazine January 2014 evaluated As a second variable the size of the antipad is chosen and a two factor multiple level DOE is performed Both single ended and differential insertion loss is investigated and an analysis of variance approach is used to determine the level of influ ence of the variables stub length and antipad size at various frequencies up to 40 GHz The frequency of the quarter wave length resonance is correlated to the stub length and the increase of the insertion loss well below the resonance point is discussed The test vehicle and the performed measure ments are detailed and the article discusses the electrical performance characteristics of the var ious test cells Later a recommendation for an acceptable stub length is given Introduction Driven by steadily increasing bandwidth demand for networking infrastructure and the amount of data handled in ever enlarging serv er installations the transmission characteristics of the transmitting channel must be optimized ventec rv lo 3 asons You WIN withVentec article INFLUENCE OF VIA STUB LENGTH AND
34. ad design decisions that result from poor models can delay a product s ship date by months and the lost sales could probably pay off your house What s a user to do While there are numer ous programs that claim to detect and correct issues with S parameter data causality and pas sivity being two of the most popular issues we maintain that users should take a close look at S parameter data before letting a computer pro gram change it This means develop ing techniques to evaluate the quality of S parameter data Dr Michael Steinberger s article TDR Reading the Tea Leaves outlines the use of TDR tech niques to do just that Design ers can use these techniques to understand the topology that the S parameter data describes and its key charac teristics If those characteris tics don t reasonably match the circuit being modeled then there s really not much point in worrying about whether the data is passive and causal and how it might be corrected The same is true for semiconductor models Ba sic characteristics of the I O circuitry output and termi nation impedance voltage swing ESD capacitance slew rate non linearity equaliza tion and more can be ob served by exercising a model under the right test condi tions If the model meets reason able expectations great it s time to start running system design simulations If not it s time to figure out what s going on with the model before run
35. again In the U S we ve had to deal with the reper cussions of the budget sequestration artificial slowing of the economy and the government shutdown by a few radicals another artificial slowing of the economy It s been painful We need to pull out all the stops and allow the economy to grow at full speed We can work on the structural stuff later once we have full employment and tax revenues flowing in We take two steps forward then one step back It s crazy Market news is getting the most reader interest from our websites Anything with mar ket information seems to be of great importance these days Leading indicators from The Conference Board captured indicators have been climb ing for most of 2013 which GE bought Imbera Electronics Of money to ensure that i a good thing just not fast to advance its capabilities into advanced embedded electronics packaging LTX Credence bought Dover s Multitest and ECT while Molex bought FCT Electronics only to be acquired by Koch one month later Flextronics made a few acquisitions picking up RIWISA to strengthen its position in medi cal They also picked up a couple of factories from Motorola Mobility Google one in Brazil and the other in China Sparton bought Creo nix to strengthen its mil aero offerings and also picked up Aydin Displays They bought Onyx at the end of 2012 Jabil bought Nypro OSI bought Briton EMS Season Group acquired OEL ENRI merged wi
36. agni tude of the insertion loss was plotted for each of the 400 measurements in one chart Figure 11 To get a less noisy picture of the influence of the stub length and the antipad sizes the data of the five panels and two identical cou pons for each stub length antipad size combi nation were averaged and plotted Figure 12 The via stubs cause a large resonant dip with the longest stubs creating the notches in the insertion loss curve at lower frequencies than the shorter stubs The antipad size generates some small changes but with less of a clear effect than the stub length To evaluate the influence of the antipad size an ANOVA was performed with results presented in Figures 17 19 20 To answer the question of the maximum ac ceptable stub length the additional insertion loss caused by the via stubs is extracted from January 2014 The PCB Design Magazine 51 article INFLUENCE OF VIA STUB LENGTH AND ANTIPAD SIZE ON THE INSERTION LOSS PROFILE continues Figure 11 Raw data for S21 magnitude Increase of insertion loss due to via stub this data with a de trend operation and plotted in Figure 13 As an example a maximum additional in sertion loss of 5 dB might be acceptable at fre quencies up to 20 GHz Using the chart in Figure 13 and adding a forbidden zone red hatched box it can be found that the stub lengths SEO8 SEO9 and SE10 are too long and therefore add too much insertion loss The stub length
37. and Power Integrity Simplified 5 Johanson Dielectrics Basics of Ceramic Chip Capacitors 6 Kemet SMT Capacitor Comparison 7 X2Y Understanding capacitor inductance 8 The ICD PDN Planner is available at www icd com au Barry Olney is managing direc tor of In Circuit Design Pty Ltd ICD Australia ICD is a PCB design service bureau that spe cializing in board level simula 5 tion The company developed the ICD Stackup Planner and the ICD PDN Planner software To read past columns or contact Olney click here S V YX Engineering Delivering peace of mind to the industry since 1998 Ap M maxim LOCKHEED integrated MARTIN GENERAL intel cadence DYNAMICS g These are just some of the major corporations that have DEM NIS inus Jf spxiSFACTION GUARANTEED article Antipat Size on the Insertion Loss Profile by Alexander Ippich MULTEK INC SUMMARY What effect do via stub length and antipad size have on resonant frequency and inser tion loss profile This article focuses on an inves tigation into these issues and offers recommenda tions for optimum via stub length Abstract The growing transmission speed and vol ume of digital content increases the pressure on reduction of overall insertion loss of printed cir cuit boards permanently In today s circuit boards it is not only the transmission line itself but also the via struc ture that imp
38. anel PCB L2 4754 5 00 5 25 5 50 r r r r g 1 2 3 4 5 1 2 6 7 antipad SE 4 50 _ a cO 475 iin 5 004 5 25 5 504 T T T T tor 50 60 80 90 01 02 03 04 05 06 07 08 09 10 Figure 19 Main effect plot for insertion loss at 5 GHz 54 The PCB Design Magazine s January 2014 article INFLUENCE OF VIA STUB LENGTH AND ANTIPAD SIZE ON THE INSERTION LOSS PROFILE continues marginally above 10 GHz To quantify the effect of the two parameters antipad size and stub length the numeric out put from the ANOVA evaluation is used The data show that the stub length accounts for 98 of the variation in the resonance frequen cy where the antipad size has an effect of less than 2 Figure 18 Another ANOVA was performed to investi gate the influence of panel number PCB num ber antipad size and stub length on the abso lute insertion loss value This can be done for every frequency in the captured data 10 MHz to 40 GHz Here only the data for 5 GHz and 10 GHz are presented as an example For both frequencies there is hardly any variation over the PCB number location of the coupon on the panel Some variation can be seen between the five manufactured panels Again the antipad size has a small influence with the larger clearances causing less insertion loss The main contributor is the stub length causing an increase in the single ended inser tion loss from around 4 5 5 5 dB at 5 GHz The
39. ay out of the way That s the only area of real concern I have When you look at the raft of new technologies under develop ment conventional and alternative energy printed electronics 3D new products based on exciting materials like graphene the U S and Europe are in pretty good position to capture serious market share Those innovations will translate into some type of electronics which will drive our industry forward The U S now has a pretty solid and reliable energy supply Huge improvements to the energy infrastruc ture will keep energy prices relatively stable for years to come a huge benefit for our manu facturers This gives companies confidence that the costs of manufacturing will be fairly stable as they expand their businesses Infrastructure and rule of law IP protection proximity to customers and low levels of corruption are ad vantages we have over most of the developing world As a result I think we ll see some surpris ing on shoring initiatives in 2014 as companies make the move back to North America China will continue to lose its luster Things are begin ning to come back into balance Another change we re starting to see and will continue to see expand in 2014 is the num ber of talented young people entering the in dustry It has been a cry heard for years at indus try events Where are all the young people How can we get them involved in the industry Actually these engineers product designers
40. can Flex interconnects are the most reliable packaging solution for your advanced electronics From simple single layer jumpers to complex rigid flex circuit boards we design and manufacture a wide range of flexible circuits for military and commercial avionics artillery and munitions tactical communications and other mission critical applications Capable of OVERSIZED PANEL PROCESSING up to 6 feet long Markets Industrial Medical Military Aerospace Board Types Double sided Flex Rigid Flex Other Sculpted Flex Circuits Flex Harness Mfg Volumes Prototype Small Medium Large Other Services Assembly CAD Design PCB layout Quick turn around Turn key Specialities Controlled Impedance RF Sc Rigid Flex Flex Harness Turn amp tested Flex Circuits 5 9100 ISO 9001 ITAR register Click here to see a demo gt Capabilities listing for advanced search functionality Specialties and certifications listing Ability to upload brochures and videos Quick and easy Contact and RFQ buttons News web and contact links www thepcblist com article INFLUENCE OF VIA STUB LENGTH AND ANTIPAD SIZE ON THE INSERTION LOSS PROFILE continues General Linear Model 5GHz versus panel antipad size diff Factor Type Levels Values panel fixed 5 panel 1l panel 2 panel 3 panel 4 panel 5 antipad size fixed 2 50mil 80mil diff fixed 10 diff O1 diff 02 diff 03 diff 04 diff 05 diff 06 diff 07 diff
41. ch with 21 capacitors the 60mQ impedance of the V shape of the target frequency approach some as high as 800mQ below 1GHz which is 13 times higher than the target impedance If an odd harmonic was to fall on that particular frequency then emissions would also be very high at that frequency From extensive simulations I have noticed that there is a direct correlation between AC impedance peaks and electromagnetic radiation In fact if a board fails electromagnetic compliancy emis sions can be dampened by changing the capaci tors to ones that have a self resonant frequency SRF close to the radiating frequency The optimized value approach illustrated in Figure 5 has 21 capacitors of different values and numbers to optimize the overall AC impedance In this case 21 capacitors from 10uF to 4 7nF are used This approach gives a response below the target impedance from 2MHz to 158MHz The low end is of little consequence as the op erating frequency of concern is much higher And you will also note that there are no anti resonant peaks in this case because the values are so close together the overlaps dampen the 36 The PCB Design Magazine January 2014 peaks When the SRFs are spread the parallel resonant impedance sets the limits to the PDN performance There are a few ways to reduce the anti resonant peaks 1 Adjust the capacitor values so that the SRFs are closer to the anti resonate peaks 2 Add a capacitor with a
42. ctrical Delay Phase Offset Favorites LCL Figure 23 Screen shot of differential insertion loss testing tion of the display shows the amplitude of the differential insertion loss SDD21 The orange trace is for a coupon with nearly optimum back drilling minimum stub with the yellow trace showing SDD21 for a differential pair with long via stubs The bottom portion of the screenshot displays the amplitude left and phase right of all 16 mixed mode S parameters For the differential testing mixed mode S parameters were measured on 10 different stub lengths two different antipad sizes and five panels testing from 10 MHz to 40 GHz with 2048 points Similar as with the single ended data the magnitude of the differential insertion loss was plotted for all 100 differential pairs to check for unusual readings Figure 24 The av erages over the five panels were plotted for the 10 stub lengths and two antipad sizes to visual ize the impact of the parameters Figure 25 Figure 25 clearly demonstrates the increase of the resonant frequency for shorter stub lengths and also some smaller changes caused by the antipad size To get the full picture on the influence of the panel the antipad size and the stub length an analysis of variance on the magnitude of SDD21 was conducted for various frequencies Figure 26 shows the main effect plot of this ANOVA for a frequency of 5 GHz The main effect plot confirms a very small pan
43. did not support defining and simulating bends and folds in the flex portion of the design Worse yet they didn t even support defining different layer stacks in different parts of the design or even what areas constituted the flex part of the design As a result rigid flex designers had to manu ally determine how to translate a 3D design of the rigid and flexible sections into a flat 2 D representation suitable for fabrication This further required them to manually document all areas that were flexible They also had to double check to ensure that they did not place components or vias near the transitions be tween rigid and flexible portions of the design This also included many additional rules which were mostly not supported in the PCB design software at the time As suggested earlier any successful rigid flex design requires that the design team work close ly with the fabricator The following Golden article AN INTRODUCTION TO RIGID FLEX DESIGN BEST PRACTICES continues Rules for the project aim for successful produc tion and eliminating preventable re spins Golden Rules Communicate with the fabricator Qualify the fabricator s capability to build the planned rigid flex design Involve the fabricator as early as possible in the design process Collaborate so the design s layer stack matches the fabricator s processes Use IPC 2223 as the common point of reference with the fabricator Otherwise com mu
44. el to panel variation The effect of the an tipad size is slightly larger but the main influ ence clearly is the stub length To get quantita January 2014 The PCB Design Magazine 57 article INFLUENCE OF VIA STUB LENGTH AND ANTIPAD SIZE ON THE INSERTION LOSS PROFILE continues Figure 24 Raw data of SDD21 magnitude Figure 25 Average data for magnitude of SDD21 Main Effects Plot for 10GHz Data Means panel antipad size I X vy o bI o 39 Fe w 4 e gg Ki diff 10 15 20 25 30 rrara YF OFF FSI FO SH ELLE EEE EEF Figure 26 Main effect plot for magnitude SDD21 at 5 GHz tive data on the effects the numerical ANOVA Cross Section Evaluation data is evaluated showing the panel to have After completing the TDR and VNA evalu only a 0 7 variation and the antipad size to ac ation actual stub length measurements of the count for 3 5 of the variation The stub length launch vias have been made using cross sec causes 91 3 of the variation which therefore tions Figure 28 shows examples of the depths has by far the largest influence Figure 27 between SEO1 which was virtually no stub at 58 The PCB Design Magazine January 2014 the JC list THE best way to find a PCB fabricator anywhere Londonderry New Hampshire U S A amp 9 Website Me RFQ Vul can About Contact Specs Videos Photos Brochures News Lightweight space saving Vul
45. en combined result in a high level of complexity For designers who develop rigid flex designs the biggest challenge remains How do I define all of the areas layers and stacks The answer Use a table to define the stack layer design As a general characteristic most rigid flex designs exhibit different layer stacks in different areas of the design One simple way Copy the design outline on a mechanical layer Then create a fill pattern that to identify the rigid and flexible portions of the design that contain a different layer stack as shown in Figure 2 The simplified design in Figure 2 uses the matching graphic fill patterns the two columns on the right of the table to identify the flex ible and rigid areas of the board respectively For example the layer named Dielectric 1 is an FR 4 core With the different layer stacks de fined any rigid flex design team now confronts January 2014 The PCB Design Magazine 29 article AN INTRODUCTION TO RIGID FLEX DESIGN BEST PRACTICES continues Lauer Name Material Thickness Constant Flexible Rigid RUG EE nec c E 7475772 Eee ES Le uc SSS ELLA SRS 3 Top Solder Coveriay PD 0 501 J PY 4 Top Lauer Copper i 4wii Pee SSS S PiBsse Polyimide 1 40 48 77777 Wire Te De eem SSS NNN Bottom Layer Bottom Solder Bottom Overla Bottom Paste 5 a IS 10 specifying bends and folds
46. ers it is even possible to engrave incredibly fine structues onto the head of a match without igniting it In recognition of their outstanding work German President Joachim Gauck presented Jens K nig Dirk Sutter and Stefan Nolte with the German Future Prize 2013 on December 7 4 2013 The price for technol ogy and innovation honors top scientific work that displays great economic potential This highly respected prize has been awarded annually since 1997 and comes with 250 000 euros 4 in prize money CONFERENCE amp EXHIBITION March 25 27 2014 MEETINGS amp EDUCATION March 23 27 2014 MANDALAY BAY RESORT AND CONVENTION CENTER LAS VEGAS NEVADA WWW IPCAPEXEXPO ORG FocusedjEducationy Design NEW IDEAS FOR NEW HORIZONS Educational program featuring presentations by experts in design Three hour classes led by subject matter experts Basic CID and advanced CID More than 400 exhibitors displaying technology equipment and products For more information on design focused programs visit DESIGN PRINTED BOARDS ELECTRONICS ASSEMBLY TEST Masha aie i us3 don PGBDesign00 Amsaviontit Top 10 Most read PCB Design Magazine Articles of 2013 When our contributors speak people listen We ve compiled a list of 10 of the most read PCB Design Magazine articles in 2013 Take another look and enjoy these gems one more time Top 10 Most read PCBDesign007 Columns of 2013
47. ers because they increase stresses on copper traces during bending A Multilayer Technology COMPLETION Solutions for Every Complex Situation At Multilayer Technology we have the skills and the knowledge to be able to say Yes We Can to your most complex design requirements We specialize in High Speed Digital and RF Design constraints In addition we offer the following solution based services Extensive Exotic Material Processing Pre DFM Services Available State of the Art Industry Leading Processes Space Based Reliability Requirements Standard REQUEST A QUOTE SS 3835 Conflans Rd Irving TX 75061 3914 WWW MULTILAYER COM Ui H i 972 790 0062 MiL PRF 55110 AN INTRODUCTION TO RIGID FLEX DESIGN BEST PRACTICES continues Figure 3 In this commercially produced design the designers obviously did not apply bookbinder construction resulting in additional stress on the separated layers red arrow Do not abruptly change trace widths When traces enter a pad often in alignment an abrupt change in trace width creates a weak spot As a good design practice use a teardrop pattern to gradually change the width of traces connecting to pads and vias in the flex circuits Use hatched polygons A normal rect angular pour still retains heavily biased stresses in 0 45 and 90 directions A hexagon by comparison statistically provides a more opti mal hatch patter
48. et of design rules the de signer can develop with the fabricator s input These considerations include the number of layers in the design materials selections rec ommended sizes for traces and vias adhesion methods and dimensional control In the past seasoned PCB designers by passed rigid flex circuit design by connecting two rigid PCBs with a flexible cable This ap proach worked well for short run designs How ever this approach adds the cost of connectors on each board the cost of assembling the con nectors to the board and the flexible cable In Figure 1 the chart maps the cost trade off be tween a traditional rigid PCB and cable assem bly and a 3D rigid flex design Our family is over 250 strong and growing We have more than 250 active customers and we give each and every one industry leading service and support They are like family to us In addition to delivering quality and reliability we take the time to provide the service and support that makes each job a great experience for every member of our growing family Learn more about Sounds great Dragon Circuits Let s start a quote CIRCUITS Legendary manufacturing service and engineering www dragoncircuits com info dragoncircuits com 972 790 7610 article AN INTRODUCTION TO RIGID FLEX DESIGN BEST PRACTICES continues 60 00 50 00 40 00 30 00 20 00 PCB Assembly Unit Cost 10 00 0 00 10 100 500
49. g PCB design and em bedded computing and FPGA hardware and software and has research interests in signal processing audio electronics and PCB design Ben Jordan has worked as an account engineer field account engineer and in marketing and management roles at Altium since 2004 that it becomes a thermal mass says study co author Ricard Gonzalez Cinca The second system incorporates a more so phisticated series of mirrors and a heat engine The mirrors are Fresnel reflectors which con centrate solar rays upon a fluid filled tube This heat converts the liquid into a gas which heats the thermal mass At night heat is transferred to a Stirling engine to produce elec tricity January 2014 The PCB Design Magazine 33 BEYOND DESIGN PDN Planning and 2 Capacitor Selection Part 2 by Barry Olney IN CIRCUIT DESIGN PTY LTD AUSTRALIA In last month s column PDN Planning and Capacitor Selection Part 1 we looked closely at how to choose the right capacitor to lower the AC impedance of the power distribution net work PDN at a particular frequency We also examined capacitor properties and types of ca pacitors that are readily available and touched on the target frequency approach for analyzing a PDN This month we will continue on from there looking at the one capacitor value per de cade and optimized value approaches Figure 4 shows the effect of using the one value per decade approach where capacitors f
50. hairman of IBM There is no reason for any individual to have a computer in his home Ken Olsen founder of legendary mini computer company DEC So we went to Atari and said Hey we ve got this amazing thing even built with some of your parts and what do you think about funding us Or we ll give it to you We just want to do it Pay our salary we ll come work for you And they said No So then we went to Hewlett Packard and they said Hey we don t need you You haven t got through college yet Apple Computer Inc founder Steve Jobs on attempts to get Atari and HP interested in his and Steve Wozniak s personal computer Fortunately these three boneheaded visions couldn t have been more wrong printed circuit boards are the backbone of electronic technol ogy and have taken us to a place that none of these prophets could have imagined in their wildest dreams The smartphone market is ap proaching a billion units a year with tablets adding another 400 million to this number Ev ery one of these devices has at least one printed circuit board that needs to be redesigned and replaced with each new generation launch Keep Your Chin Up Process equipment manufacturers are grow ing at a solid rate which is a positive indicator for the PCB industry as a whole Laminate and other material suppliers are also showing slight growth So 2013 was a bit of a wash but in this 2013 A LOOK BACK continue
51. he Japanese PCB industry is following N Ameri ca s trajectory Once a 12 billion domestic out put Japanese PCB production is dropping to 5 billion asymptotically while its overseas production continues to increase However profits are declin ing continuously January 2014 The PCB Design Magazine 67 audris For the IPC Calendar of Events For the SMTA Calendar of Events For a complete listing check out The PCB Design Magazine s International Electronic Components Trade Show January 15 17 2014 Tokyo Japan Microtech Japan January 15 17 2014 Tokyo Japan Electrotest Japan January 15 17 2014 Tokyo Japan Material Japan January 15 17 2014 Tokyo Japan NEPCON Japan January 15 17 2014 Tokyo Japan PWB Expo january 15 17 2014 Tokyo Japan 15th IC Packaging Expo january 15 17 2014 Tokyo Japan Lighting Japan january 15 17 2014 Tokyo Japan CAR ELE Japan january 15 17 2014 Tokyo Japan EV Japan january 15 17 2014 Tokyo Japan DesignCon 2014 january 29 30 2014 Santa Clara California SPIE Electronic Imaging February 2 6 2014 San Francisco USA Pan Pacific Microelectronics Symposium February 11 13 2014 The Big Island Hawaii 68 The PCB Design Magazine January 2014 PUBLISHER BARRY MATTIES barry iconnect007 com PUBLISHER RAY RASMUSSEN 916 337 4402 ray iconnect007 com SALES MANAGER BARB HOCKADAY 916 6
52. he pad the length and width of traces connected to the pad and the way the vias are connected to the power and ground planes The location of the power ground planes in the PCB This technology provides an effective approach for decoupling pling capacitors have little effect over 1GHz and the only way to reduce the AC impedance of the PDN above this frequency is to use ECM or al ternatively on die capacitance These ultra thin laminates replace the conventional power and ground planes and have excellent stability of di electric constant and loss up to 15GHz In Figure 6 the ICD PDN Planner shows the one value per decade approach including the voltage regulator module VRM which is mainly inductive the total loop inductance of each capacitor via spreading inductance and the plane capacitance The plane resonance can be seen on the right In each case a 0 24mil 3M ECM that provides 20nF in was used to drop the PDN to below the simulated target imped ance up to 1 3GHz By comparison the target frequency and the opti mized value approached in Fig ure 7 also have the VRM loop inductance and plane capaci tance of 3M ECM included stackup controls the height high performance ICs So which approach is best of the via Inductance directly N E 1 The target frequency ap depends on the magnetic field whilst also reducing proach gives a clean V shape so reducing the energy associ electromagnetic with just one small an
53. htly below nomi nal with an average single ended impedance of 47 6 ohm and an average differential imped ance of 97 2 ohms on layer 3 The detailed read ings can be found in table 1 48 The PCB Design Magazine January 2014 200 ym 10 mil nominal stub 40 mil nominal stub Single Ended Insertion Loss Testing Measurement of single ended and differen tial insertion loss of the transmission lines in cluding the effect of the via stubs was performed on a 4 port vector network analyzer capable of going to 40 GHz High quality coaxial cables with 2 92 mm connectors with a frequency rat ing of 40 GHz were used A minimum warm up period of two hours was ensured prior to calibration of the vector network analyzer For this purpose an electronic calibration module connected directly to the end of the coaxial cables was used After com pletion of the calibration the cables connected directly to the compression mount connec tors on the test boards without any additional adapters needed INFLUENCE OF VIA STUB LENGTH AND ANTIPAD SIZE ON THE INSERTION LOSS PROFILE continues impedance test coupons T i 1 differential test coupons Figure 7 Test panel layout a S E g g g a y a W g t 4 single ended transmission lines J 10 long 1 3 5mm connectors at both ends 4 stub length between 0 and 100mil nominal Figure 8 Single ended coupon with connectors mounted
54. ict SUCCESS DFMStream provides powerful DFM capal in an easy to use tool suite designed to help engineers and designers verify design and manufacturing rules on PCB design databases Gerber and NC data any time during the PCB design cycle DFMStream bridges the gap between engineering and fabrication helps save valuable time and reduces new product introduction bottle necks Provides powerful DFM functionality Easy to learn even for infrequent users Easy to implement as part of the everyday design flow Saves time and increases productivity nenne DEM CHee E area socorponentesadi Ea can be ver with unique rules differen from rest of design For more information visit downstreamtech com or call 800 535 3226 NENNEN ee Q DownStream trademarks are the property of their respective owners INFLUENCE OF VIA STUB LENGTH AND ANTIPAD SIZE ON THE INSERTION LOSS PROFILE continues E 0 mil nominal stub Impedance Control To assure good matching of the transmis sion lines to the measurement equipment the single ended and differential impedance of the traces was measured on each test panel For ease of testing dedicated impedance coupons Fig ure 7 were used in conjunction with handheld probing heads and a standard volume manu facturing impedance test system The impedance testing confirmed that both the differences between the panels and between the two produced work orders were minimal The absolute values were slig
55. in 2 D space This means that every rigid flex designer must docu ment where critical design elements cross the boundaries between rigid and flexible sections Keeping the Flex in Rigid Flex Staggered Length Circuits This design practice also called bookbinder construction adds a small amount of length layer by layer moving outward from the bend radius This method allows the circuit to bend in only one direction A common rule of thumb is to add additional length to a subsequent lay er roughly 1 5 times the thickness of the indi vidual layer But that value varies depending on the tightness of the bend and the number of 30 The PCB Design Magazine January 2014 1 40mi Coverlay PD 0 50mi 4 Ea Ss LS MZAA ISSSSSS San usu a ERE Figure 2 Fill patterns in this table s flexible and rigid columns identify the rigid and flexible areas of the board layers This is another instance where a paper doll mockup can provide an informative quick check Bookbinder construction relieves ten sion produced during bending and also prevents buckling of the inner layers near the bend radius More Golden Rules Avoid bending at the corners Cop per traces perform best when placed at right an gles to the flexible circuit bend In cases where bending is unavoidable one alternative is to use conical radius bends Use curved traces Avoid hard right angle traces and even 45 hard corn
56. in the world for Gross Domes tic Product growth in 2013 at 1 796 forecasts for 2014 are only slightly better at 2 896 pull ing ahead of only Japan and the EU Whether it is RoHS conflict min erals or the EPA restrictive leg islation continues to make it harder for PCB manufactur ers to not only make a prof it but survive Look for the biggest to get bigger through acquisitions both domesti cally and globally In 1990 there were rough ly around 1 000 U S printed circuit board manufacturers in 2000 there were 700 and in 2010 the number of domes tic shops had fallen to only 365 Unfortunately I fear this number will be less than 300 by the end of 2015 a short two years away Where the U S market needs to contin ue to compete are QTA proto business advanced technol ogy and short run orders Global PCB Snapshot The global printed circuit board industry s total available market is currently at a little more than 60 billion with Asia still dominat ing world production There are a little over 2 900 printed circuit board manufacturers glob ally and the United States held onto its fifth place rank with just under a 596 share which may look encouraging However this is ex tremely misleading as the top four countries are responsible for 8996 of the total global PCB pie People much smarter than me are only forecast ing single digit growth of the industry for the next five years Bright Spots Looking Forward
57. l 1 1 13 C MA020 23313 38 203 203 80 1 30 30 12 prepreg Ies PMASUPAMAR 33132116 56 37 m6 20 95 Bot 8 Seconday Side Tacos as um el to Tun pated copper 5 22 soldermask 1 04 J measured traces on L3 Q probing from L1 imb dem ber EC x m l1 3p asl 2 backdrilling from L8 towards L3 must not cut layer Figure 4 Stackup of the test vehicle 3 10 different stub lengths from approximately zero to 100mils 3 4 different antipad sizes from 50mil to 90mil diameter 3 2 identical single ended insertion loss coupons per panel J one differential insertion loss coupon per panel 2 one single ended and one differential impedance coupon per panel J total of 5 panels Figure 5 Design features ers was identical on L2 L4 L5 and L7 but they were modified between 50 mil and 90 mil in diameter for the various coupons The primary drill plated through hole was back drilled from the bottom side of the test vehi cle to different depths resulting in nominal stub lengths between around 100 mil down 46 The PCB Design Magazine January 2014 to practically no stub at all Figure 5 Some of these stub lengths can be seen in Figure 6 An overview of the test panel with the vari ous backdrill and insertion loss coupons is giv en in Figure 7 and an example of one of the coupons populated with the flange mount con nectors is shown in Figure 8 We Have a Better Way PCB MANUFACTURING to Pred
58. litzy and it isn t exciting but it is critically important if we want to use SI simula tions to create high quality products Welcome to 2014 and stay off my lawn PCBDESIGN Todd Westerhoff is vice presi dent of semiconductor relations for SiSoft has over 34 years of experience in the modeling and analysis of electronic systems including 17 years of signal integrity experience He can be reached by clicking here video interview Dragon Circuits Old Company New Name and Ideas by Real Time with SMTAI Real Raj and Gunny Barbaria ac quired North Texas Circuit Boards and began rebuilding the failing company After shedding some longtime em ployees and investing in new equipment the two say they are ready to make Dragon Circuits into a 21 century technology company They also discuss their drive to make PCBs attractive to the next generation 14 The PCB Design Magazine January 2014 with VIDEO PRESENTATION PRESENTED BY I CONNECTOO7 realtimewith com Advanced PCB Solutions HA will WHAT DO WE BRING TO THE RF MICROWAVE MARKET EXPERIENCE EATON JE TORMANCE Our unique Partial Plating Process enables Proven track record with RF Microwave several copper thicknesses on the same board materials like RO6002 and 2929 Bondply Our unique processes enable us to create solutions that meet the needs of the demanding RF Microwave market at competitive prices We use materials fr
59. mous quotes on the topic PCBDESIGN The reason a lot of people do not recognize op portunity is because it usually goes around wearing overalls looking like hard work Thomas A Edison A pessimist sees the difficulty in every opportu nity an optimist sees the opportunity in every dif ficulty wWinston Churchill Ray Rasmussen is the pub lisher and chief editor for l Connect007 publications He has worked in the industry since 1978 and is the former publisher and chief editor of CircuiTree Magazine To read past columns or to contact Rasmussen click here January 2014 The PCB Design Magazine 25 by Ben Jordan ALTIUM SUMMARY Once considered too costly by many designers rigid flex circuits are becoming more prevalent every day Now designers are learn ing how to deal with this seemingly schizophrenic product format Designers increasingly face project require ments for densely populated electronic circuits including pressures to reduce manufacturing times and costs To meet these requirements design teams have increasingly turned to 3D rigid flex circuits to meet their project s perfor mance and production requirements As a first step rigid flex designs require closer collabora tion between the designer and fabricator than 26 The PCB Design Magazine January 2014 traditional board and cable designs The trade offs required to produce a successful rigid flex design translate to a s
60. n Add pad support Compared to FR 4 copper on a flexible PI substrate is more likely to detach due to repeated stresses involved in bending plus lower adhesion Consider surface mount pads and non plated through holes to be unsupported Many fabricators recommend additional through hole plating and recom mend additional SMT pad support such as an choring stubs and reduced coverlay openings Stagger double sided flex traces Running traces over each other in the same di rection distributes tensions between the copper 32 The PCB Design Magazine January 2014 layers unevenly Staggering the traces reduces or eliminates the problem In harmony with the clear trend of increas ing rigid flex PCB manufacturing updated PCB CAD tools now include the necessary features needed to design rigid flex circuits These in clude multiple layer stack management com ponents mounted on inner flex circuit layers and 3D visualization and simulation of the flex circuit portions Figure 4 demonstrates these ca pabilities In addition to the layer stack management and 3D visualization clearance checking of the components on the flex substrate is also pos sible The design rule check engine provides early warning for rigid flex designs whenever the final bend radii results in mechanical inter ferences See Figure 5 Electronic design is becoming a 3D world And as more rigid PCB designers face techno logical pressure many are turni
61. neering experience dates back to 1993 He received his degree in electrical engineer ing from University Stuttgart Germany January 2014 The PCB Design Magazine 61 Mil Aero007 News Highlights Ducommun Gains Major Parker Aerospace Airbus Contract The company has received a multiyear contract from Parker Aerospace a unit of Parker Hannifin Corporation to produce complex PCBs assemblies for use in the fuel management system of the Air bus A350 family of commercial aircraft The award has a potential value in excess of 20 million over the contract period Sparton USSI JV Nets 2 8M in Subcontracts Sparton Corporation and USSI a subsidiary of Ultra Electronics Holdings plc announce the award of subcontracts valued at 2 8 million from their ERAPSCO SonobuoyTech Systems joint venture Axis Leads 2014 UK Aerospace Youth Rocketry Challenge Axis Electronics apprentices joined more than 25 MPs who teamed up with aerospace apprentices from all over the UK to take part in a rocket launch ing competition The aim was to achieve the great est vertical distance Blackfox Lockheed Martin Celebrate IMET is Philadelphia s Manufacturer of the Year IMET Corporation a contract manufacturer pro viding electronics engineering services and PCB assembly has received the 31st annual Manufac turer of The Year Excellence Award by The Greater Philadelphia Chamber of Commerce NASA CCAM Partner to Advance
62. nes to the outside at each end of the traces In addition single ended and differential impedance test coupons were placed on the panel The size of the antipads on the plane lay January 2014 The PCB Design Magazine 45 article INFLUENCE OF VIA STUB LENGTH AND ANTIPAD SIZE ON THE INSERTION LOSS PROFILE continues Customer Multek Codename Signal integrity Backdrill Test Vehicle Stackup Proposal P SBACKDR TV 01 1820100 5415 anticipated fina Board Thi Joe T Iis Finish ENIG 2985 175 Tkness mci p awi 1205 Board thickness spec 32000 l m Jover copper Total thickness including soldermask 3 081 1213 Tolerance 1000 10 0 Themes For Gace ners Wesen yay Former Byers Tem T deiere nome se se joue aahei Mutek Code woa Mutek Matenal code paca content constant thekness lamination lamination For copper layers aiana Iz FIT len 5 Ini socemask 10 10 04 Top Primary Side Tacos NEN 55 55 22 prepreg 15415 TO P MASCO 331342100 58 37 245 240 95 1 E 30 12 core 15415 MA mi tit 313 VV C MA020 2x3313 38 205 203 80 sig 3 VLP BF TZA 1 30 30 12 prepreg 15415 P MATO P MA4Q0 39313 2116 58 37 25 20 56 EE NND 1 30 EJ 12 core I5415 MA S mi 1 1 6x7628 S S C MA004 8x7628 00 1448 1448 57 0 ms a wo a T2 prepreg 15415 P MA3T0 P MA400 331342116 58 37 285 218 86 sig 6 vue ara 1 30 30 12 core 15415 MA Bmi
63. ng to rigid flex circuits to help them meet these requirements Fortunately EDA companies are incorporating article AN INTRODUCTION TO RIGID FLEX DESIGN BEST PRACTICES continues Figure 4 An example rigid flex PCB design in Altium Designer s 3D mode showing intended bends in the flex circuit areas improved rigid flex design capabilities into ex isting PCB design tools PCBDESIGN Sources amp Additional Reading 1 Clyde F Coombs Jr Ed Flexible Cir cuit Applications and Materials Chapter 61 in Printed Circuits Handbook Sixth Edition 2008 McGraw Hill 2 Joseph Fjelstad Flexible Circuit Technol ogy p 186 Fourth Edition 2011 BR Publishing Group Hopes to Produce Electricity On the Moon at Night Researchers from the Polytechnic University of Catalonia and U S collaborators have stud ied two options for storing energy on the moon during the day for use at night The first system consists of modifying frag ments of regolith or lunar soil incorporating el ements such as aluminium for example such Figure 5 Simulated bending of a flex circuit reveals a clearance violation between a flex mounted pin header and SMDs on the main rigid board The violating components are highlighted green 3 Benjamin Jordan Ruminating Rigid Flex Part 1 5 Flex Circuit Materials Altium Live Blog available here Ben Jordan has more than 20 years of electronics experience includin
64. nication in the form of documentation can cause errors and misunderstandings resulting in costly delays Graduate from delivering Gerber files to the fabricator Instead deliver files in ODB v7 0 or later or in a format that meets IPC 2581 because either format identifies specific layer types for clear documentation For a successful rigid flex design the design team must also select the materials that bal ance as always cost versus performance Most conventional PCB boards start with a rigid fiber glass epoxy substrate Although termed rigid fiberglass epoxy substrates exhibit some flex ibility but not enough for more complex ap plications that involve movement For 3D rigid flex designs dimensionally stable flexible and heat resistant polyimide PI film is the most common choice It remains rea sonably stable due to low thermal expansion and contraction relative to PET while also tol erating multiple reflow cycles Polyester PET also commonly used but does not tolerate high temperatures well and is less dimensionally stable than PI As well thin fiberglass epoxy cores also find application in rigid flex circuits Besides substrates the design will require addi tional films usually PI or PET but sometimes flexible solder mask ink for coverlay The cov erlay protects the outer surface components and conductors from damage and corrosion and in sulates the conductors as well By definition rigid flex ci
65. ning simulations that will have to be rerun later anyway As I write this I can t help but think that Im coming across as a spoilsport I imagine the grumpy old man sitting on his front porch yelling at kids who walk across his lawn ex cept that he s saying Mind your S parameters young man Test your I O models to make sure they accurately represent return loss As I ve already conceded testing simula tion models is neither quick nor enjoyable And Thermal Polyurethane amp management solutions Water and solvent based cleaning Conformal coatings In electro chemical solutions we reign In the formulation manufacture and supply of conformal coatings thermal pastes encapsulants cleaners and lubricants we have the solution Through collaboration and research we re developing new environmentally friendly products for many of the world s best known industrial and domestic manufacturers always to ISO standards Combine this unique ability to offer the complete solution with our global presence and you have a more reliable supply chain and a security of scale that ensures you receive an exemplary service Isn t it time you discovered how Electrolube can serve you Simply call or visit our website 44 0 1530 419600 www electrolube com Contact lubricants Maintenance amp service aids Las Vegas March 25 27 2014 Visit us Booth 2119 ELECTROLUBE THE SOLUTIONS PEOPLE
66. nized the way hu mans interact with computers not to mention how we all work and communicate Engelbart was also a pioneer in the creation of the Inter net predecessor ARPANet hypertext and video the shaughnessy report conferencing technology among a long list of accomplishments But he ll always be remem bered for the mouse William Lowe passed on at 72 He led the IBM team that developed its first PC in one year a feat that no one including IBM thought possible IBM was a behemoth and not known for its quick turnaround time But Lowe bypassed the firm s usual years long pro prietary development model by using exist ing technology The IBM 5150 incorporated Microsoft s MS DOS 1 0 operating system and an Intel 8088 microprocessor In 1981 Lowe s idea put IBM at the top of the tech mountain if only for a while Ray Dolby died at 80 with 50 patents to his name not to mention a few Oscars for his work with movie audio As a child he stud ied the vibrations of clarinet reeds He got his Ph D in physics launched Dolby Laboratories and changed sound forever If you re my age or older you may remember how music sounded back in the pre Dolby days especially guitar driven rock and roll Back then total harmonic distortion THD ratings were a big consideration when buying a stereo There was so much hiss that I hated to turn up the volume too loud which made it tough to enjoy the music But then stereos start
67. nsions which has an impact on global business U S consumer confidence has not improved and is still hov ering around 8096 The unemployment rate is 7 2 published which is bad enough but af ter factoring in the millions of people that are no longer counted because they have flat out quit looking the real unemployment number 3 D g E 5 App Store isa service mark of Apple Inc Google Pl bd ZUKEN Cut your PCB design time Step up to CADSTAR Start your trial today Advanced 45 degree routing and pushing The ultimate in speed and precision for manual routing the Activ 45 router provides single click follow me routing with automatic completion using push aside springback and segment break options to tackle even the most complex layout challenges Be a Smart designer Download the CADSTAR App PEEL CADSTAR Touch is a free PCB design productivity App that allows AppStore remote control of CADSTAR s view and program functions anita D C Ala e Pan Zoom View all Run Macros More CADSTAR includes Schematics High speed routing EMC Constraint Browser Signal Integrity 3D Mechanical verification Placement Planner Power Integrity CA S i A R CADSTAR Proven expert desktop PCB design solution www zuken com cadstar trial Westford MA USA Tel 888 332 7227 2013 A LOOK BACK continues is somewhere north of 1496 Forbes BLS The U S is dead last
68. om 714 970 2430 THE SHAUGHNESSY REPORT The Old Guard Moves On by Andy Shaughnessy I CONNECTO07 We ve officially entered 2014 How can that even be possible If you look back at the year in terms of trade shows it seems like we just left IPC APEX EXPO in San Diego But now we re gearing up for trade show season again The year ahead is ripe with promise The jobless rate recently dropped to 796 the low est in five years and more jobs were added to the economy in December than analysts ex pected And surprisingly the U S government hasn t shut down in nearly three months Did the Democrats and Republicans secretly agree to quit calling each other names and actually work together Probably not but we can hope But before we get caught up in 2014 let s look back at the truly great innovators we lost Sr ow Doug Engelbart inventor of the computer mouse 8 The PCB Design Magazine January 2014 in 2013 Doug Engelbart inventor of the com puter mouse died at 88 He served in WWII as a Navy radar technician and later went to work at the Stanford Research Institute where he de veloped the computer mouse in the 1960s and was awarded a patent in 1970 At first even his peers wondered why any one would need such a thing It wasn t the most technologically advanced idea it was a wooden box with two wheels and a red button It wasn t even called a mouse in the patent paperwork But it revolutio
69. om Rogers Arlon Teflon and GETEK depending on the customers requests We also work with hybrid materials WE DON T JUST SAY IT WE CAN PROVE IT CLICK TO LEARN MORE PERFORMANCE Impedance traces with 5 or less rj highly accurate top to bottom registration Candor Industries Inc www candorind com 416 736 6306 Feature column POINT OF VIEW 2013 A Look Back A by Steve Williams After a very challenging year for the domes tic PCB industry global business conditions are slowly improving Let s take a look back at 2013 and also a look forward to what we can expect as we move into the New Year Like many of you I grew up in this business Icut my teeth and more than a few body parts in this industry working for my dad in the fam ily business At the risk of dating myself this was well before the advent of CNC machines CAD CAM and automatic plating equipment Throughout the past three decades I have been proud to see this business grow into the profes sional industry it has become I am vested in the success of our industry it matters to me mu 16 The PCB Design Magazine January 2014 2013 News Flash The U S economy is still not working After a number of false starts missteps and failed technologies in the renewable indus try solar photovoltaic demand is beginning to recover Europe s tighter fiscal policies have squeezed consumer purchasing power and in creased sovereign debt te
70. opment said Dr Thom as Dekorsy general manager 62 The PCB Design Magazine January 2014 1 72 Billion The Aircraft Electronics Association announced its third quarter Avionics Market Report for this year In the months of July August and September 2013 total worldwide avionics sales amounted to 1 721 888 397 14 or more than 1 72 billion as reported by the 20 aviation electronics manufac turers participating in the report We are Commited to Delivering Outstanding Quality and Service On Timp CUSTOMERS AGREE Dear Prototron Team Thanks for your continued performance and quality We have had 35 engineering designs fabricated by Prototron since 2012 and we are very happy Your personal contact knowledgeable staff and commitment to on time delivery continues to allow us to meet our commitments to our customers Prototron s engineering department has been extremely helpful on recommending improvements to new PCB designs You guys are great Thanks Fred Sievert Aeroflex Colorado Springs Click to Learn More Prototron FASTEST A Circuits America s Board Shop Quality printed circuit boards www prototron com video interview Blackfox Expands With Veteran Tra by Real Time with aa Al Dill CEO and founder of Blackfox Training Institute discusses his company s tremendous growth over the past few years Blackfox offers training for veterans including a program that allo
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73. r resistor and inductor These are referred to as the capacitance value ESR and ESL respectively The downward slope of the capacitor is capacitive then as the capacitor approaches its SRF it becomes resistive then as the frequency increases the inductance takes over raising the impedance again To meet the target low impedance at a particular frequency a capacitance value is cho sen so that when mounted on the PCB it will resonate at the desired frequency and have an impedance that is equal to its ESR The combination of capacitors causes anti resonant peaks where one goes capacitive while the other is inductive When the SRFs are spread the parallel resonant impedance sets the limits to the PDN performance The mounting inductance is comprised of three components Capacitor footprint and fanout capacitor height above or below the plane and power plane spreading inductance Embedded Capacitance technology allows fora very thin dielectric layer 0 24 2 0mil that provides distributive decoupling capacitance and takes the place of conventional discrete de coupling capacitors over 1GHz PCBDESIGN 40 The PCB Design Magazine January 2014 References 1 Barry Olney Beyond Design Power Dis tribution Network Planning and Material Selec tion for SERDES Design 2 Henry Ott Electromagnetic Compatibil ity Engineering 3 Istvan Novak Quiet Power Resonances in Power Planes 4 Eric Bogatin Signal
74. rcuits impose ad ditional requirements when selecting conduc tor materials Electrodeposited ED copper foils used in traditional PCB designs fall short of the necessary flexibility and toughness properties needed in a rigid flex design Rigid flex designs utilize a variety of higher performance conduc tor materials and methods However the two most common are medium priced high ductil ity electrodeposited HD ED and higher cost rolled annealed RA copper foils In the early stages of the process the rigid flex design team members face a balancing act They must define the mechanical challenges of the projected use cases balanced against the electrical performance requirements These two considerations often butt heads requiring the designer to balance and resolve the two As a first step to arriving at the optimal design the design team can gain considerable insight by producing a physical paper doll mock up of the circuit The mockup pinpoints potential form and fit problems early in the design pro cess As modern CAD tools progress they in clude 3D modeling of rigid flex designs The most up to date add animation However de veloping a 3D computer model involves consid erable design steps so an initial paper mock up still proves to be informative Rigid Flex Design Best Practices The term rigid flex points to one of the most significant design details Rigid flex circuit designs involve multiple elements that wh
75. rom each decade are added in parallel Now to Impedance Frequency Hz Figure 4 One value capacitor per decade approach 34 The PCB Design Magazine s January 2014 be fair I have added three of each value from 100uF to 1pF to total 27 capacitors as the target frequency approach in Figure 2 had a total of 29 capacitors In this case the impedance is below the target impedance from 10KHz to 110MHz Notice how the combination of capacitors causes anti resonant parallel resonant peaks where the higher frequency capacitor goes ca pacitive while the lower frequency capacitor is inductive This occurs as the LC network pro duced by the combination is effectively a tank circuit that has parallel resonance at the crossing frequency This happens each time a different value of capacitor is added These peaks exceed N N T N N We Deliver A 5 Star Performance At U S Circuit we are UL Certified to build with Rogers FR408 family amp Rogers 370HR as well as Isola Speed materials U S CIRCUIT Manufacturer of Printed Circuit Boards U S Circuit Incorporated 2071 Wineridge Place Escondido CA 92029 Ph 760 489 1413 Fax 760 489 2965 www uscircuit com ITAR Registered ISO 9001 2008 MIL PRF 55110G beyond design PDN PLANNING AND CAPACITOR SELECTION PART 2 continues Or Impedance 001 001 Frequency Hz Zpdn 0 06090 Freq 15 Figure 5 The optimized value approa
76. rs both military and commercial OEMs who are looking for the latest in HDI high reliability PCBs for their products PCBs for LED Lighting The Times They Are a Changing BPA forecast that the market for PCBs providing enhanced thermal and power management will reach over 3 2 billion by 2020 BPA discusses some of the research in their report Metal in the Board Opportunities for Printed Circuits Pro viding Thermal and Power Management 2012 2020 Wurth Elektronik HDI Microvia PCBs Now Available The HDI specialist W rth Elektronik has set new standards in the PCB industry HDI microvia PCBs are now available in its online shop WEdirekt With just a few clicks your HDI PCB is calculated and the price is shown immediately online Ordering pro totypes is considerably simplified and faster Canadian Circuits Acquires Oxford CMI 900 Unit Praveen Arya president and owner of Canadian Circuits Inc announces that his company has ac quired a new Oxford CMI 900 X ray fluorescence 20 The PCB Design Magazine January 2014 coating thickness measurement system as part of the company s complete equipment upgrade PCB Solutions Offers Expanded Stocking Program Effective in December 2013 PCB Solutions is pleased to announce offering enhancements to their stocking program PCB Solutions is now offer ing a complete stocking program that enables cus tomers to take advantage of volume pricing but assists them
77. rt and 4 port S parameters were X evaluations like the analysis of variance ANO measured on all test boards The data was trans VA to find the vital few parameters The setup ferred into a spreadsheet and statistics software for single ended insertion loss testing can be to allow plotting of the parameters and further found in Figure 9 50 The PCB Design Magazine January 2014 INFLUENCE OF VIA STUB LENGTH AND ANTIPAD SIZE ON THE INSERTION LOSS PROFILE continues File Trace Chan Response Marker Analysis Stimulus Utility Help Trace 1 Marker 5 26 5000000000 GHz Single Groups Continuous Restart Hold CH1 amp Mem C 2 Port Favorites LCL Figure 10 Screen shot of single ended insertion loss testing A screenshot of typical measurement data is shown in Figure 10 The orange trace in the upper portion of the display is the magnitude of insertion loss over the full frequency range for a coupon with a very short stub where the yellow trace is for a long stub The lower part of the screenshot shows magnitude and phase for all four single ended S parameters For single ended structures four different antipad sizes and 10 different stub lengths were measured on five panels with two identical cou pons each This resulted in 400 full 2 port S pa rameter matrices spanning the frequency range from 10 MHz up to 40 GHz with 2048 points To exclude odd readings in the data the m
78. s economy that is a win and with any luck 2014 looks to be a little better PcBDESIGN This column appeared in the December 2013 issue of The PCB Magazine Steve Williams is the president of Steve Williams Consulting LLC www stevewilliamscon sulting com and the former strategic sourcing manager for Plexus Corp He is the author of Quality 101 Handbook and Survival Is Not Mandatory 10 Things Every CEO Should Know About Lean To read past columns or to contact Williams click here aphene Sees the Li Graphene a one atom thick sheet of carbon that is extremely strong and conducts electric ity well is the thinnest material ever made Re searchers believe that it could be used as a trans parent electrode in photovoltaic cells replacing a layer of indium tin oxide ITO that is brittle and becoming increasingly expensive Wee Shing Koh of the A STAR Institute of High Performance Computing in Singapore and co workers have compared these two ma terials They found that graphene outperforms ITO when used with solar cells that absorb a broad spectrum of light Square sheets of graphene produced by today s chemical vapor deposition technology have an electrical re sistance roughly four times that of a typical 100 nanometer thick layer of ITO Although adding more layers of graphene reduces its resistance it also blocks more light Koh and his co workers calculated that four layers of graphene st
79. s really six of one and half a dozen of the other Personally I prefer the target fre quency approach as it is less time consuming to analyze and requires fewer parts this means that the BOM count is reduced holding stock is reduced and assembly equipment setup and placement times are greatly reduced This all leads to reduction in cost and time to market and of course a more reliable end product Also January 2014 The PCB Design Magazine 37 beyond design PDN PLANNING AND CAPACITOR SELECTION PART 2 continues E KO Stachup Fanner Feid Solver Technology wiwid comau Fe Edt bpon Setup Hap D3Ho 5vcO s 040080 Susp aye FON oem ied MEMS VRM inductive oo Fee ont eo Vase M Teak Qni 7000 Irae Fig o To Tansert C SETTE Vage C p Marteg Va Laco F uctece V Va Soende ON D Gy Vash ESAN ESUDM Peg Sde 1 Tono oot m T joom je oa wo oon enm enr 3 m ome 2exs em j 3 oor zr lowe gt E E 01 oms n ono oo jous rusm ouo ance of 3M ECM this method can be used to dampen electromag netic emissions at a particular frequency Either way each PDN on the board should be analyzed to give confidence in the final product Points to Remember There are three approaches to analyzing the PDN target frequency one value capacitor per decade or optimized value Poor PDN design can
80. th Abotron eXception Group sold to TPG Gold man Sachs Probe bought Trident JUKI and Sony merged their SMT equipment businesses 24 The PCB Design Magazine January 2014 enough All economists be lieve economic growth is being hindered by partisan politics in the U S Congress IPC continues to evolve and along with it some more personnel changes We ve lost Susan Filz conference coordinator and Mary MacK innon APEX show sales IPC has also added PERM into the stable of groups under its con trol PERM is a group working to help high reliability companies move to lead free Driven mostly by mil aero suppliers they re working hard on a solution for tin whiskers They made some good but rather expensive progress As one gentleman from Raytheon said at the re cent tin whiskers conference they haven t seen any increase in failures due to whiskers but he also acknowledged they are spending a ton of money to ensure that IPC also broke bread with SMTA by co locat ing their fall meeting in conjunction with the SMTAI show It seemed to work well for both groups Let s hope for more cooperation and ultimately the merger of these groups A bright spot for me in 2013 was the new Viasystems factory in Anaheim I liked that It s good to see what may be a taste of things to come Let s hope so Looking ahead What can we expect in 2014 I m optimis tic It sure seems like the market is ready to roll if politics can st
81. this is a mechanical operation im proving the depth accuracy is not simple and very often complicates the process significantly which in turn increases cost It is important to understand how much stub is still acceptable in a given application to avoid excessive strength ening of the via stub specification To get real data on the effect of the via stubs single ended and differential channels were cre ated with stub lengths varying from practically zero to close to 100 mils As a second parameter the sizes of the antipads on the reference layers have been modified Two port and 4 port S pa rameters were collected on these test structures and an analysis of variance ANOVA 5 ap proach was used to evaluate the effect of these parameters on the magnitude of the insertion loss as well as on the quarter wave resonance frequency without backdrill Figure 2 A board 0 220 in thickness 44 The PCB Design Magazine January 2014 with backdrill article INFLUENCE OF VIA STUB LENGTH AND ANTIPAD SIZE ON THE INSERTION LOSS PROFILE continues tub lengt lecreasin 20 L03 521 48 L05 325 L07 x to9 L11 35 with backdrill 40 00E 00 10E 09 20E 09 30E 09 40E 09 50E409 6 0E 09 70E 09 80E 09 90E 09 10E 10 116410 12E 10 frequency Hz Figure 3 Influence of stub length on insertion loss profile Measurement Results that Prompted the
82. ti reso ated with the loop area reduc nant peak at 40MHz and is be interference es overall inductance The inductance associated with current spreading into the power ground planes also contrib utes to the total mounted inductance Current in the planes becomes concentrated in the vicinity of the vias This current creates a high magnetic field and therefore contributes to inductance With the continuous trend to smaller fea ture sizes and faster signal rise times planar ca pacitor laminate or embedded capacitor materi als ECM is becoming a cost effective solution for improved power integrity This technology provides an effective approach for decoupling high performance ICs whilst also reducing elec tromagnetic interference Planar capacitor technology allows for a very thin dielectric layer 0 24 2 0mil that provides distributive decoupling capacitance of 20nF in in this case This also increases real estate space reduces the number of vias and opens up rout ing channels Unfortunately standard decou low the target impedance up to 1 3GHz 2 The one value capacitor per decade approach has one peak at 23MHz and is also below the target impedance up to 1 3GHz and 3 The optimized value approach is also good from 2 3MHz to 1 3GHz with a peak at IMHz But in reality only plane capacitance on die capacitance or changing the plane size area can reduce the impedance beyond several 100MHz So it i
83. with cash flow and inventory relief SOMACIS Receives Innovation Award from JDSU At the 2013 JDSU Global Supplier Day SOMA CIS received the Excellence in Value Innovation Award This recognition confirms SOMACIS focus in delivering innovative solutions through high tech PCBs combined with co design services Cicor Realigns from Four Divisions to Two Cicor an international high tech industrial group and leader in the fields of PCBs microelectronics and electronic solutions headquartered in Boudry Switzerland is optimizing its existing organiza tional structure to better align with customers fu ture needs Integral s Zeta Certification Awarded to Eagle Circuits Integral Technology Inc a manufacturer and dis tributor of HDI electronic materials for the PCB industry has announced that Eagle Circuits of Dal las Texas has received the prestigious Zeta amp Cer tification allowing them to produce circuit boards using Integral s revolutionary dielectric films AT amp S EmPower Consortium Aims to Optimize Energy Use Targets include the improvement of processes for semiconductor manufacturing development of new concepts for component packaging and design of products for optimum management of energy Quality PCBs from the industry leader With over 40 years of experience delivering high quality PCB prototypes Sunstone Circuits is committed to improving the prototyping process for the design
84. ws vets who pass the curriculum to secure jobs at Lockheed Martin Real ng Services with VIDEO PRESENTATION PRESENTED BY I GONNECTOO7 realtimewith com Pulse Laser Wins German Future Prize 2013 Scientists from Bosch TRUMPF Jena Uni versity and Fraunhofer IOF have turned the ultra short pulse laser into an effective series production tool For their collective effort they were awarded the German Future Prize 2013 on December 4 2013 Although lasers are an indispensable part of industrial manufacturing in some areas conven tional systems are reaching the limits of what they can do A laser beam directed at a piece of metal will cause the metal to heat up and partially vaporize and melt How ever controlling the properties of melted materials is extremely difficult imperfections develop meaning that manufacturers still have to go to the trouble of re working the workpiece This costs both time and money 64 The PCB Design Magazine January 2014 Little by little a USP laser can remove or ab late tiny areas measuring just a few millionths of a millimeter nanometers At lightning speed a computer controlled mirror system makes sure the laser pulses hit the right spot Hundreds of thousands of pulses per second lead to a melt free processing with unparalleled precision explains Dr Jens K nig from technology com pany Bosch Using cold ablation as it is also known among engine

The PCB Design Magazine, January 2014 Issue

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