High temperature storage influence on molding compound properties

An electronic device cannot perform its designed functions until it is packaged such that it is interconnected with the rest of the system and protected. As an encapsulation material, thermosetting polymers are widely used. It is well known that properties of polymer-based composites like molding compounds are highly affected by the influence of temperature, relative humidity and degree of conversion. The effect of above mentioned internal and external circumstances are investigated extensively in the past. Surprisingly the effect of high temperature storage on the mechanical properties is scarcely studied. From literatures research it is concluded that high temperature storage and postcure treatments increases the glass transition temperature. Also a weight loss during high temperature storage is reported [1], [2].