Development of a tapeless lead-on-chip (LOC) package

A double-sided adhesive tape is typically used as an insulator and mechanical buffer layer between the chip and lead frame in lead-on-chip (LOC) packages. The costs associated with the lead frame and tape process make the current LOC package ten times more expensive than conventional packaging. A new tapeless LOC package process has been developed which significantly reduces the production costs. In this new process, the tape is replaced by a thermoplastic adhesive layer deposited on the polyimide coated wafer. This paper describes the optimum thermoplastic material properties for the adhesive layer, the fabrication process parameters, and the experimental and simulated reliability and performance results of the tapeless LOC package