Construction of Mother Boards Interconnecting Mcm's

After the decision is made to use MCM's in an electronic system, and the specific MCM technology is selected, there still remains the problem of their termination to the next level of packaging, where advanced techniques will be required to fabricate the interconnecting mother board. This paper will describe the design of a very compact mother board interconnecting 9 MCM-C's and all the necessary I/O terminations to the rest of the system within 5" by 5.5" usable area of a standard SEM-E format. The mother board uses MiCroWire/sup TM/ interconnection technology and is less than 0.060" thick, containing 4065 gold plated pads for MCM and connector interconnections, with a density of 148 pads/ in^2. MCM terminations are formed with a body centered 0.100" Land Grid Aray pattern (LGA). For this military computer system, a Solder Free Interconnection/sup TM/ (SFI) method is used between MCM's and the mother board in order to facilitate removal and replacement of MCM's in the field with a minimum loss of time and effort.