Flip chip MPU module on high performance printed circuit board “ALIVH”

This paper describes of a flip chip MPU module on a high performance “ALIVH^TM (any layer inner via hole)” printed circuit board structure for sub-note PCs using a modified SBB ^TM (stud bump bonding) technique. The SBB technique is an advanced flip-chip bonding technique for high density multichip modules (MCMs), which can mount bare LSI chips directly on substrates. The structure of the bonding portion is composed of Au bumps with two-stepped construction and conductive adhesives. The ALIVH substrate is a high density and high performance multilayered printed wiring board with any layer inner via hole structure, via hole processing technology using a CO₂ laser and interconnection technology that employs conductive paste. In this fabricated MPU module, 4 LSI chips are mounted on an 8-layer ALIVH substrate and the clock frequency is 160 MHz. The weight of the module was reduced to 40% of that of the conventional module