Semiconductor plastic package and process for the production thereof

A process for the production of a double-side metal-foil-clad laminate for a semiconductor plastic package structured by disposing a metal sheet of nearly the same size as a printed circuit board nearly in the center in the thickness direction of the printed circuit board, providing at least one exposed metal sheet protrusion of nearly the same size as a semiconductor chip on one surface of the printed circuit board, fixing the semiconductor chip thereon, connecting the semiconductor chip to a signal propagation circuit conductor formed on a printed circuit board surface in the vicinity thereof by wire bonding, at least connecting the signal propagation circuit conductor on the printed circuit board surface to a signal propagation circuit conductor formed on the other surface of the printed circuit board or a connecting conductor pad of a solder ball with a through-hole conductor, and encapsulating the semiconductor chip with a resin,

• the process comprising the steps of
• (1) forming a protrusion on one surface of the metal sheet for mounting the semiconductor chip, and forming a clearance hole having a diameter greater than the diameter of a through-hole or a slit whose minor side is greater than the diameter of the through-hole for providing the through-hole for the conduction of front and reverse circuit conductors,
• (2) disposing a low-flow or no-flow prepreg sheet or resin layer having a hole slightly greater than the area of the protrusion portion on the protrusion position on the side where the metal protrusion portion is formed, disposing a high-flow prepreg sheet or resin layer having a resin amount and a resin flow for being sufficiently filled in the clearance hole on the other side, and disposing metal foils or single-side metal-foil-clad laminates on both outer sides thereof, and
• (3) laminate-forming the resultant set under heat and under pressure, to integrate it and form a metal-sheet-inserted dual-side metal-foil-clad laminate.