Multi-Step Cure Process for Void-Free Silicone Resin Encapsulant

摘要

In general, rapid cure reaction for LED encapsulant silicone resin causes serious defects in the cured resin product such as warpage, residual void, and decreasing wetablility. In order to remove residual voids in a silicone resin, multi-step cure processes were tested in the present investigation. Three kinds of multi-step cure processes were applied and residual voids were observed. Experimental observation showed that most of the voids were removed under 70℃ which is the minimum temperature for activating chemical cure reaction. In addition, degree of cure (DOC) and temperature distribution were predicted by using FEM analysis of heat transfer. It was concluded that cure temperature of the DOC smaller than 0.5～0.6 is an effective way to minimize the residual void and stress.