Experimental Methods for Stress and Strain Analysis of Advanced Electronics Packaging

  Prof. Jeffrey C. Suhling

  Quina Professor and Department Chair, Department of Mechanical Engineering, and Center for Advanced Vehicle and Extreme Environment Electronics (CAVE3), Auburn University, IEEE Fellow,USA                                                                                 

Abstract:

Electronics packaging is a field in rapid evolution due to strong and competing customer demands for increased functionality and performance, further miniaturization, heightened reliability, and lower costs.  Such product drivers cause a myriad of reliability challenges for the engineer involved in the mechanical design of electronic systems.  Accordingly, advanced experimental techniques are in high demand, and several methods of experimental solid mechanics have become critical tools for design and development of electronic products.  In this short course, a presentation is made of most important and widely adopted experimental techniques that are applied to packaging for measurements of stress, strain, and deformation including 

(1) Silicon Test Chips with Stress and Temperature Sensors; 

(2) Scanning Acoustic Microscopy (CSAM); 

(3) Digital Image Correlation (DIC); 

(4) Optical methods for Characterization of Warpage; 

(5) Moiré and Interferometric Techniques; 

(6) Micromechanical Characterization of Solders, Underfills, and Thin Films.  

To begin the course, the mechanics and reliability issues for modern electronic systems will be reviewed, and the challenges facing the experimentalist in the packaging field discussed.  For each experimental method, discussion will be given of the theoretical fundamentals and equations that form the basis of the technique, as well as of the practical approaches and “tricks of the trade” needed by the experimentalist for successful implementation to advanced electronic packages and assemblies.  Designs for specialized instruments and testing systems based on these methods will also be shown.  Finally, a comparison of the capabilities of the various methods will be made as well as identifying the best techniques for various applications.  Several case studies will be presented.

Outline

1. Mechanics and Reliability Issues for Modern Electronic Systems

2. Experiment Methods for Measurement of Stress, Strain, and Deformation

· Silicon Test Chips with Stress and Temperature Sensors

· Scanning Acoustic Microscopy (CSAM)

· Digital Image Correlation (DIC)

· Optical methods for Characterization of Warpage

· Moiré and Interferometric Techniques

· Micromechanical Characterization of Solders, Underfills, and Thin Films

3. Case Studies

· Measurement of Molding Induced Die Stresses

· Delamination Detection at Material Interfaces in Flip Chip and Molded Packages

· Evaluation of Solder Joint Deformations and Strains in Area Array Packaging

· Warpage Measurements for Die, Components, and Substrates

· Evaluation of Transient Deformations and Strains During Drop Tests

Lecturer Biography:

Jeffrey C. Suhling received his Ph.D. degree in Engineering Mechanics from the University of Wisconsin in 1985. He then joined the faculty of the Department of Mechanical Engineering at Auburn University, and currently holds the rank of Quina Distinguished Professor. He served as the Center Director for the NSF Center for Advanced Vehicle Electronics (CAVE) from 2002-2008, and as ME Department Chair from 2008-2025. His research concentrates on the mechanics, reliability, and materials science of electronic packaging and semiconductors; with emphasis on stress sensors and test chips, material characterization and constitutive modeling, and reliability testing and modeling. Dr. Suhling has co-authored over 600 technical publications on electronics packaging, with over 15,000 citations and an H-Index of 63 on Google Scholar.  He has advised over 100 graduate students at Auburn University including over 40 PhD students working in the electronics industry and academia. He is a Fellow of ASME, Senior Member of IEEE, and member of SMTA and IMAPS.  Dr. Suhling has been a member of the IEEE Electronics Packaging Society for the past 35 years, and is serving as Society President for a two-year term in 2026-2027.  He received the EPS William Chen Distinguished Service Award in 2024.