US Patent 7585699 Semiconductor package board using a metal base

A semiconductor package board for mounting thereon a semiconductor chip includes a metal base having an opening for receiving therein the semiconductor chip and a multilayer wiring film layered onto the metal base. The semiconductor chip is flip-chip bonded onto the metal pads disposed on the multilayer wiring film within the opening. The surface of the metal base is flush with the top surface of the semiconductor chip received in the opening. The resultant semiconductor device has a larger number of external pins and a smaller deformation without using a stiffener.