Impurities of Epoxy Novolac Resins and their Influence on the Reliability of Encapsulated Semiconductors.

Abstract

Impurities, especially chemically bonded impurities, of o-cresol novolac epoxy resins and their influence on the moisture resistance and other properties of the epoxy molding compounds have been investigated to clarify the influence of impurities of epoxy resins on the reliability of encapsulated semiconductor. As a result, the existence of hydrolyzable chlorine and hydroxyl group-containing impurities has been confirmed, and it was found that the impurity such as a hydrolyzable chlorine causes undesirable influence on both the moisture resistance and electrical properties at high temperatures. It was also found that the impurity such as a hydroxyl group causes undesirable influence on the moisture resistance, and that the lower hydroxyl content gives the higher heat resistance as a result of an increase in the epoxy content.