PRINTING ENCAPSULATION SYSTEMS (PES) OF ADVANCED MULTICHIP-MODULE ANDCOB DEVICE

Extensive study of methods to screen print an encapsulant on bare die for multipchip modules (MCM) and chip-on-board (COB), TAB, and flip-ch ip applications has produced a ''printing encapsulation system'' (PES) . The key to this system was in the development of a liquid epoxy resi n with optimum properties for printing encapsulation. We have develope d a printing encapsulation system (PES) that produces high reliability and high quality encapsulated components, free of voids and demonstra ting optimal thin consistent encapsulated shapes for advanced COB appl ications. The PES utilizes an epoxy resin we created with viscosity an d open lid storage properties appropriate for mass production. The thi xotropic properties have been adjusted carefully to allow for consiste nt high volume results. The system yields a void free encapsulated dev ice that a is resistant to thermal shock and moisture after short cure times. Full curing can be achieved in as short as 15 min, lending thi s material and process easily to in-line manufacturing.