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/cm² 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/cm². The physical and electrical characteristics of the interposers, the process and test details, manufacturing information, and reliability data are presented