Comparison of Stud Bump Bonding technology and other flip-chip technologies

We have already developed a flip-chip bonding technique for high density Multi-Chip-Module (MCM), using called Stud-Bump-Bonding (SBB) technique which can bond bare LSI chips directly to substrates. Au bumps are formed on electrode pads of the LSI chip by a wire-banding apparatus. Each Au bump has two-stepped construction and bonded with conductive adhesive to an electrode terminal formed on the substrate. We analyzed the difference of bonding property, in the case of using conductive adhesive anisotropic conductive film and solder as the bonding layer between stud bumps on LSI chips and circuit boards. It was found that the SBB technology was superior to other flip-chip technologies for the bonding property. We also performed cost simulations. It was found that the cost of packaging using the SBB technique was enough competitive compared with that of other packages under certain condition.