THE BENEFITS AND RISKS OF COPPER PILLAR-BUMPED FLIP CHIPS
By Ilknur Baylakoglu, Craig Hillman, and Micheal Pecht
Center for Advanced Life Cycle Engineering, Electronic Products and Systems Center
This paper discusses potting materials and their properties, including glass transition temperature (Tg), coefficient of thermal expansion (CTE), elastic modulus (E), and extractable ion content of potting material. Their measurement and importance to device reliability are discussed. Measurement methods are explained and compared. The characteristic of commercially available thermally cured potting materials was examined and the significance of different characteristic parameters is also discussed. Understanding of the factors affecting these material properties will provide process and design engineers to obtain optimum performance from potting materials and become cognizant of the potential reliability changes that can occur from changes in the beginning of manufacturing processing. The examined potting materials were the Emerson and Cuming Stycast 2651-40 FR, Insulcast 3258LIP, and Cytec Conapoxy FR 1403.