Encapsulant for nonhermetic multichip packaging applications

An encapsulant study that identifies a robust silicone material suitable for multichip packaging (MCP) applications is presented. The properties/characteristics of encapsulant needed for the MCP applications are identified. A literature survey then leads to the selection of six types of encapsulants for a screening test. The encapsulants were tested at 85°C/85% relative humidity with DC bias and in situ leakage current monitoring. A modified silicone encapsulant (MSE) was identified as the most promising material and was subjected to more in-depth studies. Test samples encapsulated with MSE were exposed to five selected chemicals to study their chemical resistance. The samples were then subjected to a temperature-humidity-bias (THB) test for moisture protection studies. In addition, studies such as material formulation, adhesion, mechanical protection, and temperature cycling were conducted