Structure and method for automated assembly of a tab grid array package

Abstract

A TAB Grid Array (TGA) package allows automated assembly using established manufacturing equipment similar to those used in the production of plastic ball grid Array (PBGA) package assembly. The TGA package are formed, using as starting material, a metal strip having the same critical dimensions and tooling holes as those used for a PBGA package. In this invention, the stiffener is designed to serve as a carrier throughout the assembly of the TGA package. The wire bonded TGA cavity package, including the solder balls, is first fully assembled prior to the attachment of the semiconductor die. Subsequently, the semiconductor die is attached to the stiffener, wires are bonded between the semiconductor die and the tape frame, and the entire assembly is encapsulated. The process of the present invention provides a high device assembly yield usually not achievable by the PBGA packages. The choice of high temperature tape and epoxy allows the use of high temperature solder balls which provide for higher package-to-motherboard assembly reliability. Further, the high electrical performance of the TGA package is achieved by using a two-metal layer tape. In one embodiment, the first layer is used for signal connections, the second layer is used for routing the power signal and the stiffener is used for routing the ground signal.