Interconnection Considerations for a Hybrid Mcm

A complex hybrid (mixed interconnect) MCM is described wherein wire bonded and flip chipped IC's are attached to a thin film MCM. Additionally, a TAB IC and soldered discretes are also attached. For purpose of card-level assembly, the populated thin film MCM is mechanically, thermally, and electrically enclosed in a large alumina cavity-down PGA, and hermetically sealed. The design concept enables each of the inter connection schemes to be assessed either separately or synergistically. While the design point is unlikely to be used in production, the test vehicle offers a remarkable opportunity to assess viable combinations of hybrid MCM technology that are planned for production in various forms. Several of the technology challenges associated with such hybridization at the MCM level are discussed, along with preliminary results of stress testing from this vehicle. Feasability for combining flip chip, wire bond, TAB, and soldered discretes on a thin film carrier is demonstrated.