Damage Progression in Electronic Molding Compounds under Sustained High Temperature for up to 1-year in Automotive Underhood Environments

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 electronic components capable of surviving high temperatures for long periods (>100,000 hours). In this paper, the aging effects of a number of epoxy molding compounds subjected to sustained high temperature long term aging have been studied. Two popular molding compounds, EMC-1 and EMC-2 are studied under three aging temperatures: 100°C, below glass transition temperature, 125°C, around glass transition temperature and 150°C, above glass transition temperature. The dynamic mechanical analyzer (DMA) and thermomechanical Analysis (TMA) are conducted to study the evolution of viscoelasticity, glass transition region and coefficient of thermal expansion as the function of aging time and temperature, including pristine, 40 days, 80 days, 120 days, 240 days and 360 days. TGA tests are conducted to study the weight loss change as the function of aging temperature and aging time. SEM and optical microscope are applied to study the microstructure evolution of EMCs.