ADVANCED SILICON-ON-SILICON MULTICHIP MODULE DEVELOPMENT FOR AUTOMATED PRODUCTION.

IMI PROPOSES TO UTILIZE ITS RECENT SUCCESSFUL PACKAGING RESEARCH IN MULTICHIP SILICON-ON-SILICON ASSEMBLIES TO DEVELOPA HIGH DENSITY, HIGH PERFORMANCE DESIGN FOR LOW COAST DIGITAL AND ANALOG MODULES. A CIRCUITED SILICON WAFER WILL BE UTILIZED AS A SUBSTRATEON WHICH TO MOUNT FOUR OR MORE SILICON DEVICES. TAPE AUTOMATED BONDING (TAB) WILL BE UTILIZED AS THE INTERCONNECTION TECHNOLOGY BECAUSE OFITS SUPERIOR THERMAL AND PERFORMANCE CHARACTERISTICS, AS WELL AS ITS ABILITY TO ACCOMMODATE 4 MIL PITCH BONDS, BOTH INNER AND OUTER LEAD. THE SILICON WAFER WILL HAVE 2 MIL2 GOLD BUMPS ELECTROPLATED ON THE PADS OF THE OLB FOOTPRINT. EACH CHIP WILL BE EXCISED FROM ITS TAB PATTERN AND MOUNTED TOP SIDE DOWN (FLIP TAB), WITH A SPACER MOUNTED ON THE TOP SURFACE TO: A) MAINTAIN THE POSITION OF TAB LEADS ON 4 MIL PITCH WHEN THEY ARE EXCISED, AND B) PROVIDE THE NECESSARY SPACING OF THE TAB LEADS ABOVE THE HEIGHT OF THE BUMPS TO ALLOW PATTERN RECOGNITION AND THE PRECISE POSITIONING REQUIRED FOR OUTER LEAD BONDING. ALONG WITH THEPERFORMANCE/COST TRADEOFFS, AUTOMATION FOR PRODUCTION PROCESSES WILL BE DEFINED IN PHASE I, AND DEVELOPED IN PHASE II. ANITCIPATED BENEFITS/POTENTIAL COMMERCIAL APPLICATIONS - SUCCESSFUL COMPLETION OF THIS PROJECT WILL PROVIDE ECONOMICAL OPTIONS FOR PACKAGING ENGINEERS INVOLVED IN LEADING EDGE HIGH DENSITY, HIGH PERFORMANCE REQUIREMENTS, BOTH DIGITAL AND ANALOG. AUTOMATION OF TAB INTERCONNECTED MULTICHIP SILICON-ON-SILICON MODULES WILL RESULT IN HIGH RELIABILITY AND ATTRACTIVE PRODUCTION YIELDS, ALONG WITH CIRCUIT PERFORMANCE NOT POSSIBLE WITH WIRE BONDING.