SUBJECT: Ph.D. Dissertation Defense
BY: Reinhard Powell
TIME: Thursday, April 6, 2006, 10:00 a.m.
PLACE: MARC Building, 401
TITLE: Development of Convective Solder Reflow and Projection Moire System and FEA Model for PWBA Warpage Prediction
COMMITTEE: Dr. I. Charles Ume, Chair (ME)
Dr. S. Mostafa Ghiaasiaan (ME)
Dr. Suresh Sitaraman (ME)
Dr. Russell Peak (MaRC)
Dr. C. P. Wong (MSE)
Dr. Jiahui Pan (Akrometrix, LLC)


Over the past 50 years, electronics manufacturing industry has undergone revolutionary changes, which have provided consumers with a plethora of electronic products. The increase in functionality of electronic products and decrease in cost due to continuous miniaturization and lower manufacturing costs have evolved over time. As electronics manufacturing technology becomes more advanced, reliability of electronic products and devices have become more of a concern. Thermomechanical reliability in electronics is studied in this research. Thermomechanical failures are failures due to temperature loading conditions electronic products and devices experience during manufacturing and service. The thermomechanical issue studied in this research is the effect of convective solder reflow on the warpage of packaged electronic devices, bare boards and chip packages. A convective reflow-projection moiré warpage measurement system is designed and implemented in this research. The system is the first available system capable of measuring warpage of printed wiring boards (PWBs) with and without electronic components during simulated convective reflow process. A finite element model is also developed to predict the warpage of PWBs populated with plastic ball grid array (PBGA) packages. The developed warpage measurement system as well as the developed finite element model is used to study various PWB assembly (PWBA) configurations during simulated convective reflow processes.