Issue link: https://iconnect007.uberflip.com/i/1509873
OCTOBER 2023 I PCB007 MAGAZINE 49 is an invaluable resource specifically tailored testing covering thermal cycling, mechanical loading (such as bending) and evaluating resis- tance of PCB pad to cratering. PCB007 References 11. "IPC-TR-609, Round Robin Reliability Evalu- ation of Small Diameter Plated Through Holes in Printed Wiring Boards," IPC Tech. Report, Septem- ber 1988. 12. IPC.org. 13. "Reliability of Printed Circuit Assemblies," Chapter 60, by J. Glazer, Printed Circuit Handbook, 6th edition, 2007. 14. "Three-Step Concept (TSC) in Modeling Micro- electronics Reliability (MR): Boltzmann-Arrhenius- Zhurkov (BAZ) Probabilistic Physics-of-Failure Equa- tion Sandwiched between Two Statistical Models," by E. Suhir, Microelectronics Reliability, Vol. 54, 2014. 15. Applied Reliability, Van Nostrand Reinhold, by P. Tobias and D. Trindade, New York, 1986. 16. "IST coupon testing," PWB Interconnect Solu- tions Inc. 17. "HASTS testing coupons," website, Integrated Reliability Test Systems, Inc. 18. "PCQR 2 ," Integrated Reliability Test Systems, Inc. 19. ASTM D 260-78, Standard Test Methods for DC Resistance or Conductance of Insulating Mate- rials. 20. Military specifications, Land and Maritime, 2015. 21. "Accelerated Life Testing of Flexible Printed Circuits: Part I and II," by P.J. Boddy, R.H. Delaney, J.N. Lahti, E.F. Landry, and R.C. Restrick, 14th Annual Proceedings of the IEEE Reliability Physics Sympo- sium, 1976. 22. "How Clean Is Clean in PCA," by K-L Wun, M. Ostrander, J. Baker, Proceedings of Surface Mount International, 1991. Reza Ghaffarian, PhD, has spent almost 30 years leading reliability and quality assurance activities in advanced packaging at the Jet Propulsion Lab. Microvia Failures: Time for a New Paradigm by Tim Estes and Nick Meeker The weak microvia interface problem con- tinues to be a significant reliability issue for the PCB manufacturing industry. Many OEMs have mitigated the issue by utilizing staggered rather than stacked microvias and not placing microvias directly over buried mechanical vias. While this has provided temporary relief, the need to solve the issue still exists. We currently see very little research and/or development directed towards improving microvia reliability. It is as if the industry has resigned itself to testing the quality of microvias post-fabrication rather than improving the process used to manufacture microvias. At a higher level, we believe our manufacturing processes have become too complicated, result- ing in lower yields, higher costs, and longer lead times. We need a paradigm shift in how printed circuits are manufactured. America has always led the way in the development of new technolo- gies and it is time for our industry's creative peo- ple to be given the opportunity to rethink how we manufacture printed circuits. (Source: Conductor Analysis Technologies Inc.)