THE PIN REDISTRIBUTION PROBLEM IN MULTICHIP MODULES

We introduce the pin redistribution problem (PRP), which arises from l ayout design of multi-chip modules. The problem is to redistribute the pins uniformly over the MCM substrate using a number of pin redistrib ution layers. Pin redistribution is very important in MCM design becau se it has been used to not only provide a minimum spacing between sign al wires in dense signal distribution layers, but also provide enginee ring change capability [3,4]. Moreover, our experience [10] showed tha t the capacitive coupling noise between vias (one of the major problem s in designing MCMs) induced by many layers (up to 63 layers) can be r educed using the pin redistribution technique. The goal of the problem is to minimize the number of layers required to redistribute the enti re set As a net is undefined, a number of challenging issues arise. Th ree effective approaches are proposed for solving this problem.