Integrated circuit package with optical input coupler

摘要

A plastic encapsulated integrated circuit (IC) package is disclosed which includes a conical depression or dimple precisely located over a photo-responsive semiconductor element incorporated within said integrated circuit for performing a predetermined function. The IC is encapsulated in a clear, two-part epoxy moulding compound preferably Hysol MG-18 having a tapered small depression positioned to register with the photo element but stopping short of actually touching the semiconductor photo element. Thus, the bottom of the tapered depression consists of a transparent window of sufficient thickness to protect the semiconductor element and still provide optical coupling. The minimum diameter of the light input depression located preferably at the top of the clear plastic package is designed to receive a snug fitting light pipe of Lucite or other clear material that could be used as a fiber optic element. The light pipe can be retained in the IC depression by mechanical means or optionally it can be cemented in place. A suitable light source for activating the photo-responsive semiconductor element in the IC may be a light emitting diode or an incandescent lamp.