Abstract: An apparatus and a method for forming a protective package for an EPROM circuit are disclosed. The protective package includes a two piece inner ceramic package and a molded outer plastic package. The inner ceramic package includes a base member upon which the chip is mounted for wiring to a lead frame, and also includes a protective cover with a radiation transparent window that covers and protects the chip and wires. The base member and the protective cover are bonded together to hermetically seal the chip. The molded outer plastic package is formed in a mold that includes an elastomeric plug that contacts the top of the window to isolate it from the mold cavity. The plug prevents plastic from covering the top of the window during molding.