A novel technique for known good die processing eliminates failure mechanisms caused by traditional KGD processing

Assembly of a Multi-Chip Module (MCM) using pre tested or Known Good Die (KGD) may result in a functional, electrically operational module, but the KGD screening technology employed may result in immediate or long term reliability problems. This paper reviews current KGD screening technologies including one employing enlarged bond pads to allow temporary wire bonding in a standard IC package. The effects of the enlarged bond pad as well as the temporary wire bond are detailed identifying potential reliability problems and concerns. A new and novel Flip Chip Interconnect (FCI) technique for temporary interconnect of a die´s bond pads to a test carrier using compliant, conductive thermoplastic bumps allows full electrical parameter testing and eliminates most of the reliability concerns. FCI technology, in addition to KGD processing, lends itself to direct attachment of die to MCMs.