A New Embedded Package Structure and Technology for the Next Generation of WLP, the Wafer level Fun-Out Package - WFOP (TM)

Abstract

Presenting a new embedded package structure and technology for the next generation of WLP, the Wafer level Fun-Out Package – WFOPTM. A face-down mounting style, it has a metal stainless or copper plate as a base plate of redistributed interconnection layer. The redistributed layer is fabricated with a semi-additive method of copper plating. The contact between the die pads and distributed layer is the lead type. With this structure we hope to reduce fabrication cost by using large scale panels and precise redistribution interconnect controls, and its design rule does not depend on the die size. Moreover, WFOPTM has several benefits – applicable to 50μm pad pitch, excellent thermal characteristics and noise shield by attaching the metal plate. We obtained fine reliability test results. In this paper, we report its package structure, process flow, package characteristics and reliability test results and discussion.