Development of a plastic encapsulated multichip technology for high volume, low cost commercial electronics

Non-military/non-computer electronics industry segments such as PCs, workstations, portable electronics, automotive, medical, automated test equipment and high end consumer, are evolving to higher complexity and higher performance circuits and components. At the same time, many of these industry segments are being driven to shrink size, weigh and power dissipation. Standard low cost packaging approaches such as thru-hole PCB and chip and wire hybrids, can no longer efficiently interconnect these more complex circuits. These industry segments are being forced to turn to new higher performance packaging approaches such as SMT, MCM and COB. This paper describes the development of an innovative embedded chip MCM technology that eliminates high cost structures, materials and processes in current thin film MCM technologies. A plastic encapsulated multichip technology has been developed in which an epoxy encapsulant is molded around bare die to form the MCM substrate. This new MCM process readily scales-up to high volume production and is inherently high yielding, while maintaining all of the performance advantages of the GE developed overlay HDI process. This paper describes the thermal, mechanical and chemical stability issues that drove this development, the process used to fabricate the modules and the cost and yield advantages associated with this structure