Abstract: An EPROM device is constituted by an IC lead frame having an island area and a plurality of lead wires, an EPROM IC chip mounted in the island area of the frame, a plurality of wirings, each connecting the bonding pad of the IC chip to one of the lead wires, a layer of silicone resin material formed on the upper surface of the IC chip, a window plate placed on the surface of the silicone resin layer for transmitting ultraviolet rays and bonded to the silicone resin layer, and a molded package of epoxy resin encapsulating the chip island area, the EPROM chip and the silicone resin layer so as to expose the upper surface of the window plate.

Abstract: A method for manufacturing a plastic IC package with a light receiving window, for a semiconductor IC device, which includes the steps of preparing a lead frame supporting member provided, in a central portion of a main surface thereof, with a groove for receiving a liquid molding resin therein, disposing an IC lead frame on the lead frame supporting member within a mold, and molding a plastic package so as to enclose the IC lead frame and the lead frame supporting member therein and to form an opening in the plastic package at a portion corresponding to the IC chip mounting area of the IC lead frame. An IC chip is then mounted on the IC chip mounted area and interconnected by wires with the leads of the IC lead frame. Then a light transmitting window plate is adhesively fixed over the opening in the molded plastic package.