Humidity Absorption Behavior of Silicone Gel in HVIGBT Modules

Humidity robustness is one of the main concerns regarding high-voltage IGBT (HVIGBT) modules since the modules are not hermetically sealed. HVIGBT modules are generally filled with silicone gel which has a filter effect. The humidity absorption behavior is described in this paper. The absorption behaviors under two types of condensation-test methods are compared. Also, the humidity absorption behavior under various conditions is compared. Finally, the humidity behavior under the field conditions is discussed.