RISC-based multichip modules for workstations. Performance comparison among types of MCM

Multichip module (MCM) technology is becoming important for high-performance workstations and personal computers. With the increasing clock frequency of RISC processors, the electrical design of the board has become difficult due to interconnect delay and reflection and switching noise. This paper describes two types of MCMs, each of which consists of an R4000 chip and 11 1M bit static RAM chips. One is MCM-Si, which consists of bare chips on a silicon wafer substrate. The other is MCM-C, which is made of co-fired multilayer ceramics with packaged devices on the back side of the package. The power dissipation was approximately 26 watts. The delay and noise for critical nets on the module were simulated using transmission line analysis. Furthermore, another type of MCM, MCM-D, was compared from the viewpoint of performance.