Degradation Mechanisms of Epoxy Molding Compound Subjected to High Temperature Long Term Aging

FCBGAs are finding applications in automotive underhood environments where they may be subjected to sustained temperatures of 125-200°C for sustained periods during operation. While, FCGBAs have been previously used in consumer applications where operating temperatures typically range in 55-85°C, relatively little is known on methods to design damage-tolerant packages in automotive underhood environments. There is insufficient information on plastic-encapsulated FCBGAs capable of surviving high temperatures for long periods (>100,000 hours). In this paper, the degradation mechanisms of epoxy-molding compound under sustained high temperature aging have been studied. Two popular molding compounds, EMC-1 and EMC-2 are studied under three aging temperatures of 100°C, below glass transition temperature, 125°C, around glass transition temperature and 150°C, above glass transition temperature. Thermo-gravimetric analysis has been conducted to study the weight loss change as the function of aging temperature and aging time. Differential scanning calorimetry has been conducted to study the curing behavior. The evolution of the storage modulus, loss modulus and the tangent-delta has been quantified for aging short-term aging up to 40-days and long-term aging up to 1-year at temperatures of 100°C and 150°C.