A fast, low cost method to check for moisture in epoxy molding compound

Abstract

The absorption of moisture in epoxy molding compounds can be problematic for plastic packaging manufacturers, especially in East Asian countries and areas like Hong Kong, Singapore, and Malaysia, etc. The standard test method currently for testing suspect material is by Karl Fischer Titration. It is an electrochemical method, based on the reaction of iodine with water, which requires special equipment. In this study, we have applied differential scanning calorimetry (DSC) for moisture uptake testing of epoxy molding compounds. The epoxy molding compound sample is in uncured powder form or uncured pellet material. For epoxy molding compounds, there is an endothermic peak at the temperature around 40-50/spl deg/C. This endothermic peak, which reflects the relaxation of uncured epoxy resin, is highly sensitive to moisture content. Samples were exposed to different conditions of relative humidity based on JEDEC standards, 30/spl deg/C at 60% relative humidity for 24 hours and 48 hours, respectively. This work shows that a simple DSC can be used to check suspect material for moisture contamination. It is very important for manufacturers that the epoxy molding compound prior to processing must be kept in an acceptable place to avoid moisture absorption.