Adhesion evaluation on low-cost alternatives to thermosetting epoxy encapsulants

The thermosetting epoxy curing systems have been widely used as encapsulants in the electronic packaging industry. With the continual evolving of electronic product markets, material suppliers have been challenged to provide more options to meet the requirements of advanced, yet cost effective, packaging solutions. In this paper, two low-cost alternative materials have been investigated experimentally regarding their adhesion and reliability performance, and these have then been compared with the thermosetting epoxy systems. One of the materials is thermoplastic bisphenol A epoxy/phenoxy resin, and the other is an interpenetrating polymer network composed of an epoxy curing component and a free radical polymerizable component. Some formulations of the materials being studied could exhibit excellent adhesion, durability and application reliability. While reworkability is expected for these materials, they are promising as cost effective encapsulants for electronic packaging, and may be applied with appropriate processing techniques.