Skip to content
Provided by ASME Logo The American Society of Mechanical Engineers


June 2, 2021 Tutorial (included in full conference registration)


Dr. Ephraim Suhir

Dr. Ephraim Suhir
Portland State University, Portland, OR, USA
Technical University, Vienna, Austria; and
ERS Co., 727 Alvina Ct., Los Altos CA 94024, USA

Biography: Ephraim Suhir is on the faculty of the Portland State University, Portland, OR, US; Technical University, Vienna, Austria; and James Cook University, Townsville, Queensland, Australia. He is also CEO of the SBIR ERS Co. in Los Altos, CA, USA. Ephraim is the IEEE, the ASME, the SPIE, and the IMAPS Life Fellow; the APS, the IoP (UK), and the SPE Fellow; and AIAA Associate Fellow; has authored 450+ publications, presented numerous keynote and invited talks worldwide, and received many professional awards, including 1996 Bell Labs DMTS Award (for developing effective methods for predicting the reliability of complex structures used in AT&T and Lucent Technologies products), 2004 ASME Worcester Read Warner Medal Award (for outstanding contributions to the permanent literature of engineering and laying the foundation of a new discipline “Structural Analysis of Electronic Systems”; he is the third “Russian American”, after S. Timoshenko and I. Sikorsky, who received this prestigious ASME award), the 2019 IEEE EPS Field award for seminal contributions to mechanical reliability engineering and modeling of electronic and photonic packages and systems and the 2019 IMAPS Lifetime Achievement Award.

Abstract: This tutorial focuses on the underlying reliability physics and design-for-reliability of electronic and photonic packages comprised of dissimilar materials and subjected to thermal loading because of the change in temperature. The objective of the course is to teach a mechanical, materials, electrical, reliability and/or an optical engineer to understand the physics of possible TS induced failures and how to model the thermally induced stresses and deformations and possibly prevent failures. The instructor has worked in this field for about forty years or so, and some of his publications are referred to and indicated in the course information. The following major topics are addressed: physics of TS and typical TS failures in adhesively bonded or soldered assemblies; what could possibly be done to relieve TS; role of modeling, with an emphasis on analytical ("mathematical") modeling and its interaction with finite-element analyses (FEA); TS in bi-material assemblies with a low yield stress bonding (solder) layer; design recommendations for improved reliability of electronic and photonic packages experiencing thermal loading; TS in assemblies bonded at the ends; local and global interfacial shearing TS, their interaction and possible minimization; bi- and tri-material assemblies experiencing TS; flip-chip solder joint interconnections; role of the underfill; inhomogeneously bonded assemblies and assemblies with low modulus bonds at the end; possibilities to avoid inelastic thermal strains in solder joints; TS in assemblies with identical adherends; accelerated testing of assemblies subjected to thermal loading; TS in column-grid-arrays and ball-grid-array designs; TS in thin films; thermal and lattice mismatch stresses; TS induced bow and bow-free assemblies subjected to TS; TS in optical fibers and some other TS related problems in electronic and photonic packaging; unsolved problems and possible future work.

Some major publications of the course director are:

  • E. Suhir, Avoiding Inelastic Strain in Solder Material of IC Devices, CRC Press, 2020, in production
  • E. Suhir, "The Outcome of an Engineering Undertaking of Importance Must Be Quantified to Assure its Success and Safety: Review", Journal of Aerospace Engineering and Mechanics, 4(2), 2020
  • E. Suhir, "Analytical Thermal Stress Modeling in Electronics and Photonics Engineering: Application of the Concept of Interfacial Compliance", Journal of Thermal Stresses, special issue dedicated to 90-th birthday of Prof. Richard Hetnarski, 2019
  • E. Suhir, D. Steinberg, T. Yi, eds., Dynamic Response of Electronic and Photonic Systems to Shocks and Vibrations, John Wiley, 2011
  • E. Suhir, C.-P. Wong, Y.-C. Lee, eds. Micro- and Opto-Electronic Materials and Structures: Physics, Mechanics, Design, Packaging, Reliability, 2 volumes, Springer, 2008
  • E. Suhir, "Structural Analysis in Microelectronic and Fiber Optic Systems", vol.1, "Basic Principles of Engineering Elasticity and Fundamentals of Structural Analysis", Van Nostrand Reinhold, New York, 1991.
  • E. Suhir, "Thermal Stress Failures in Microelectronic Components - Review and Extension", in A. Bar-Cohen and A. D. Kraus, eds., "Advances in Thermal Modeling of Electronic Components and Systems", Hemisphere, New York, 1988.