Manufacture of advanced Cu-PI multi chip modules

A process has been developed for fabricating advanced Cu-PI multi chip modules (MCMs). This technology has been in prototype manufacturing for three years. Several thousand MCM's or interposers, with exceptional AC and DC characteristics, have been manufactured and used in prototype systems. Each interposer allows interconnection for 4 integrated circuits, 18 chip resistors, and 9 decoupling chip capacitors. Components are attached to the interposer by a flip-chip (or C4) process. The interposers are in turn attached to larger substrates. Interposers are made up of multilayer thin film (MLTF) on a multilayer glass ceramic substrate. The MLTF consists of 7 metal layers (4 wiring, 3 power-ground). An interposer measures less than 25 mm on a side. For four signal layers, the interposer provides as much as 500 cm/cm/sup 2/ or roughly 20 meters of wiring. There are several thousand signal and power vias in each interposer, for a total via density in excess of 800 vias/cm/sup 2/. The physical and electrical characteristics of the interposers, the process and test details, manufacturing information, and reliability data are presented.<
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