System module: a new chip-on-chip module technology

A new module technology,which we named "System module", has been developed. This "System module" consists of two or more LSI chips which are divided into optimized functions, and these chips are stacked together opposite each other using small bumps by MBB technology, and it is possible to treat with this module like a single chip. This module enables one to make a system-LSI with low cost and high performance/functions. These bumps, taking the area pad arrangement, are arranged on an active element on the VLSI chip. These bumps have 15 /spl mu/m diameter, and 30 /spl mu/m pitch, and are bonded without damage by soft metal. The arrangement of each pad is optimized for chip-to-chip interconnection to transmit the signal at high speed. It was shown that this module concept is effective for a large chip size VLSI over 100 mm/sup 2/ (25% cost-down for 100 mm/sup 2/) and for different process device chips, for instant between CMOS VLSI and DRAM or flash memory. A 32 bit microcomputer emulator module which adopts this structure, has been developed.