WSI implemented with button board interconnection

Development of a cheap, high yield interconnection technology is crucial to implementing WSI circuits. However, limitations in process yield and design complexity experienced with monolithic (on-wafer) interconnect have prevented WSI from being commercially feasible. Button contacts, by providing a means of interconnecting working die for WSI processors external to the wafer, fulfil the requirements of WSI at significantly lower cost than monolithic approaches. After probe test, a printed circuit board is combined with button contacts to provide a flexible method of achieving the discretionary interconnect to good die. A prototype package has been built which demonstrates the feasibility of the authors´ WSI interconnect and packaging approach. The authors discuss the button board packaging approach, the electrical characteristics of their button contact interconnect along with future applications of this technology