High reliability epoxy encapsulating compound for power module

In this paper, high reliability epoxy encapsulating compound (EMC) suitable for a power device working at a high temperature is reported. Driven by Miniaturization of module, cost reduction by the simplification of cooling system, Tj temperature of the power module is a tendency to rise. Corresponding to this tendency, EMC is needed high heat resistant performance such as heat cycle test (TCT) and power cycle test. Conventional EMC cannot be satisfied with connection reliability over 150 degree. The difference of coefficient of thermal expansion (CTE) between EMC and other packaging materials occurs stress and delamination. To solve this problem, focusing on the relationship between TCT performance and change of mechanical properties of EMC. We suggest one approach to improve TCT performance by Considering the change of mechanical properties of EMC.