Could Low Cycle Fatigue Conditions in Solder Joint Interconnections of Aerospace Electronics be Avoided?
The following three practically important problems associated with the reliability of solder joint interconnections (SJI) in IC packages are addressed in this tutorial: 1) Could inelastic strains in the solder material be avoided by a rational physical design, thereby avoiding low-cycle fatigue conditions, and, if not, could the sizes of the inelastic strain areas be predicted and minimized? 2)The difference between an highly reliable and an insufficiently reliable IC product is “merely” in the level of their never-zero probability of failure. Since SJIs are usually the most vulnerable structural elements in an IC package design, could this probability be assessed at the design stage and made adequate for the given application? 3) Should temperature cycling accelerated testing for SJIs be replaced with a more physically meaningful, less costly, less time- and labor- consuming and, most importantly, less misleading test vehicle? The general concepts are illustrated by detailed numerical examples.
Dr. E. Suhir
(Life Fellow of IEEE, ASME, SPIE and IMAPS)
Ephraim Suhir is on the faculty of the Portland State University, Portland, OR, USA, and is also CEO of a Small Business Innovative Research (SBIR) ERS Co. in Los Altos, CA, USA. He is Foreign Full Member (Academician) of the National Academy of Engineering, Ukraine (he was born in that country); Life Fellow of the Institute of Electrical and Electronics Engineers (IEEE), the American Society of Mechanical Engineers (ASME), the Society of Optical Engineers (SPIE), and the International Microelectronics and Packaging Society (IMAPS); Fellow of the American Physical Society (APS), the Institute of Physics (IoP), UK, and the Society of Plastics Engineers (SPE); and Associate Fellow of the American Institute of Aeronautics and Astronautics (AIAA). Ephraim has authored 500+ publications (patents, technical papers, book chapters, books), presented numerous plenary, keynote, invited and contributed talks worldwide, and received many professional awards, including 1996 Bell Laboratories Distinguished Member of Technical Staff (DMTS) Award (for developing effective methods for predicting the reliability of complex structures used in AT&T and Lucent Technologies products), and 2004 ASME Worcester Read Warner Medal (for outstanding contributions to the permanent literature of engineering and laying the foundation of a new discipline “Structural Analysis of Electronic Systems”). Ephraim is the third “Russian American”, after S. Timoshenko and I. Sikorsky, who received this prestigious award. His most recent awards are 2019 IEEE Electronic Packaging Society (EPS) Field award (for seminal contributions to mechanical reliability engineering and modeling of electronic and photonic packages and systems) and 2019 Int. Microelectronic Packaging Society’s (IMAPS) Lifetime Achievement award (for making exceptional, visible, and sustained impact on the microelectronics packaging industry and technology).