Ph.D. Proposal Presentation by Hai Ding
Monday, January 27, 2003
(Dr. Charles Ume, advisor)
"Prediction and Validation of Thermomechanical Reliability in Electronic Packaging"
Thermomechanical reliability analysis of printed wiring board assemblies (PWBAs) and electronic components has been one of the primary requirements in microelectronics manufacturing. The trend in electronic packaging is to stack more structures of different materials into a PWBA. This trend raises concerns about reliability problems in general and out-of-plane displacement (warpage) in particular. Warpage is an indicator of accumulated stress and strain inside electronic packages. It causes delamination, mis-registration, solder-joint shortening/opening, and die cracking.
In this proposed research, warpage will be studied by both experimental and modeling efforts. Moiré experimental systems are developed to measure warpage both on-line under simulated thermal processes and off-line. Finite element analysis (FEA) is used to model the thermomechanical behaviors of PWBAs. The FEA results are validated with moiré measurements. Based on experimental as well as validated FEA data, statistical analysis is conducted to identify material, geometry, and process parameter effects on warpage. Once parameter effects are identified, the original design can be improved to optimize material selection, board layout, and packaging processes, thus enhancing overall reliability of electronic products. The successful completion of this research will offer powerful experimental and modeling tools for evaluating warpage. The philosophy used in this research will be proven to be a successful way for studying warpage as well as various other reliability problems in electronic packaging.