THERMALLY EFFICIENT, LOW COST 3-D MULTICHIP MODULES

FOSTER-MILLER PROPOSES TO DEVELOP A LOW COST, LOW THERMAL IMPEDANCE, MODULAR PACKAGING TECHNOLOGY TO MEET THE DOD'S REQUIREMENTS FOR A RUGGED, 3-D PACKAGE. IT IS BASED ON THE ULTRAHIGH DENSITY, LOW COST MULTICHIP PACKAGING (MCP) TECHNOLOGY FOSTER-MILLER IS CURRENTLY DEVELOPING FOR DARPA. INDIVIDUAL MULTICHIP UNITS WILL BE STACKED, ASSEMBLED AND INTERCONNECTED TO ACHIEVE EXCELLENT THERMAL, MECHANICAL AND ELECTRICAL PERFORMANCE IN A 3-D PACKAGE. IN THE MULTICHIP UNIT, HIGHLY IMPERMEABLE, LOW DIELECTRIC CONSTAN (e = 2.6) LIQUID CRYSTALLINE POLYMERS (LCP) PROVIDE HERMETICITY, CHIP-TO-CHIP INTERCONNECTIONS, AND AREA I/OS FOR MODULE-TO-MODULE CONNECTIONS. IN THE BASELINE APPROACH, Z-INTERCONNECTS ARE PROVIDED BY WELL-DEVELOPED PRINTED WIRING BOARD FABRICATION TECHNIQUES. IF REPAIRABILITY IS DESIRED, A VARIETY OF OPTIONS EXIST TO PROVIDE Z-CONNECTIONS AT THE EDGES INCLUDING BUTTON BOARDS, ELASTOMERIC CONNECTIONS AND Z-TAPE. THIS TECHNOLOGY IS APPLICABLE TO BOTH SILICON AND GAAS ICS, AND WILL BE USEFUL UP TO SEVERAL GHZ. IN PHASE I, FOSTER-MILLER WILL TEAM UP WITH ENSYSTEMS TO EVALUATE CURRENT MCP AND Z-CONNECTION TECHNOLOGIES AND SELECT A 3-D APPROACH WHICH INCORPORATES THESE INNOVATIVE FEATURES, AND PERFORM A COST-BENEFIT COMPARISON WITH OTHER 3-D APPROACHES. IN PHASE II WE WILL PROVIDE A THOROUGH ELECTRICAL, THERMAL AND MECHANICAL RELIABILITY CHARACTERIZATION OF THIS TECHNOLOGY, AND IMPLEMENT IT IN A DOD ELECTRONIC SYSTEM. DEMONSTRATION OF A HIGHLY RELIABLE, LOW-COST 3-D PACKAGE WILL ESTABLISH A FIRM BASIS FOR A COMMERCIALLY SUPPORTED PHASE III PROGRAM. ANTICIPATED BENEFITS/POTENTIAL APPLICATIONS - DARPA'S HIGH PERFORMANCE COMMUNICATIONS AND COMPUTING INITIATIVE WILL BE THE PRIMARY BENEFICIARY OF THIS DEVELOPMENT. DOD WILL BENEFIT FROM THE ABILITY TO INCORPORATE A COMPLETE COMPUTER SYSTEM IN A SMART MUNITION. IN THE COMMERCIAL SECTOR, APPLICATIONS WILL BE IN LARGE HIGH PERFORMANCE COMPUTER SYSTEMS, BUILT-IN SIGNAL PROCESSORS FOR PROCESS CONTROL SENSORS, AUTOMOTIVE ELECTRONICS, AND A WIDE RANGE OF CIVILIAN AVIONICS SYSTEMS.