Provide Additional Thermal Paths. Although Thermal 4.3. Microprocessor System Figure 4 Schematic Cross-section of Proposed Microprocessor System Mcm3 Figure 5. Configuration of Mcm3 and Its Interface to a Pci Bus

management is not critical for the MCM2 design, this design will provide information about the heat management scheme to be employed in the MCM3 design which will use GaAs chips with high thermal budget. Figure 4 shows the projected schematic cross section of the final microprocessor system MCM3 incorporating the concepts discussed. This MCM will incorporate a processor chip with fixed point and floating point units, memory management chips for instructions and data, and a clock generation chip. In addition, ten SRAMs will be mounted on the underside of the substrate to form the level-two cache. The general configuration of MCM3 and its interface through a circuit board to a PCI bus is illustrated in Figure 5. The anticipated widths of the main buses are shown.