Characterization of Au-bumped eight inch wafers for TAB assembly

TAB packaging of Fast Static RAM (FSRAM) devices is expanding rapidly. The FSRAMs are moving to manufacture on 8" wafers, so Motorola has been contemplating the expansion of the existing 6" wafer bumping fab in Chandler to create an 8" wafer bumping fab for TAB assembly for the past two years. Establishment of the 8" capability would require the investment of a very significant amount of capital. This paper addresses the use of subcontract 8" wafer bumping, services of Vendor A and Vendor B, as the strategic alternatives. This study establishes a database for the evaluation of 8" wafer bumping capability. Parallel efforts in the development of alternative inner lead bond technology has also allowed the development of a yardstick for measuring the reliability performance of the alternative TAB processes, such as bumpless, ball bumping as well as transfer bump technologies