Double-sided ceramic MCMs for spaceborne computer applications

Honeywell has developed a family of double-sided ceramic MCMs for spaceborne computer applications. These include a dual 32-bit RH32 processor module a 4/spl times/128 k/spl times/80-bit dual-port memory module, and a 32-bit computer MCM. These MCMs offer flexible architectures with single and self-checking processors, expandable cache, expandable memory depth, and an option of either radiation-hardened or commercial memory die. The MCM designs are based on standard multilayer cofired ceramic technology with several significant extensions: (1) double-sided construction for enhanced board-level component density, (2) aluminum nitride ceramic for enhanced thermal management, and (3) two-high stacked memory die. Two of the MCMs are designed as 400-lead flatpacks with identical package bodies (53 mm square) and board footprints. The 32-bit computer MCM is a 532-lead, 74/spl times/78 mm, 23-metal layer flatpack. The MCMs are surface mounted using solder standoffs to provide a mechanical and thermal interface to the printed wiring board. This paper will discuss the details of the system design, components, package design, assembly, and testing of these MCMs.