Method for making light transparent package for integrated circuit

Abstract

A light transparent package (,) for an erasable integrated circuit (,), and a method for fabricating it are disclosed. The package (,) encapsulates a leadframe (,) that carries the circuit (,). The circuit (,) is an erasable integrated circuit, including an erasable programmable read only memory device. A light transparent window material (,) immiscible in molding compound (,) is emplaced conformally on a surface (,) of the circuit (,). The window material (,) is a gel, polymer preform, or other suitable conformal window forming material adherable to both the circuit (,) and to other components of the assembly, and is transparent to light, particularly ultraviolet light, following a curing process. The molding compound (,) and window material (,) are cured in situ in a cavity (,) of a mold (,). The cavity (,) has at least one contact surface (,) that compresses the window material,to form a flattened surface (,) between the window material,and the contact surface (,) of the cavity (,). The molding compound (,), which is immiscible in the window material (,), is inserted into the cavity (,) to form the package (,) around the circuit (,) after curing. The molding compound (,) surrounds the circuit (,), a portion of the leadframe (,), and the window material (,), but does not dispose itself on the flattened surface (,). The flattened surface (,) forms the exposed window surface (,) of the light transparent window (,) in the protective package (,) after curing.