DEMOUNTABLE TAB - A NEW PATH FOR TAB TECHNOLOGY

Despite its advantage, the proliferation of TAB technology in the high lead count single chip packaging world has been somewhat limited by f actors such as high entry cost and complex board-level assembly method s. In the area of MCM's, the difficulty of rework/repair of TAB emerge s as a serious limiter. The TAB package developed at Hewlett-Packard a ddresses these very issues by providing bumpless inner lead bonding an d demountable outer lead connection (hence called Demountable TAB, or DTAB). In the present paper, a comprehensive compilation of the DTAB p ackaging scheme is presented. The package construction, assembly proce dure, PC board design considerations, thermal performance, electrical characterization and reliability testing are presented in detail.