Characterization of Viscoelastic Behavior of Epoxy Molding Compounds Subjected to Sustained High Temperature Environment up to 1 year

Electronic packaging materials 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, the electronic components 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 for viscoelasticity of epoxy molding compounds subjected to sustained high temperature long term aging have been investigated. EMC evolution is studied under 100°C, below glass transition temperature, 150°C, above glass transition temperature. Frequency sweep tests are conducted on EMC samples. TTS is applied to frequency sweep tests results. Master curves are generated. The evolution of viscoelasticity behavior under high temperature long-term aging are discussed. The effect of time-dependent relaxation modulus is discussed. FEA framework is created to study the stress-strain behavior of aged effect on Cu wire bond.