Removal of a heat spreader from an integrated circuit package to permit testing of the integrated circuit and other elements of the package

摘要

The present invention advantageously provides a method for obtaining access to an integrated circuit chip encapsulated within a device package. The present method involves positioning a masking material, i.e., gasket, adjacent to the heat spreader of the device package. The gasket includes a cavity which is aligned adjacent a portion of the heat spreader directly above the chip. An etchant injection system is then placed against the gasket. A heat spreader etchant is then injected directly into the cavity such that the etchant contacts the exposed surface of the heat spreader. The etchant is supplied to the cavity until a opening is etched vertically through the thickness of the heat spreader. If the heat spreader is composed of copper plated with nickel, it is preferred that the etchant be a solution of 70% nitric acid heated to about 80° C. Formation of the opening through the heat spreader may expose an adhesive layer. This layer may be removed using abrasion combined with nitric acid solution to expose the underside of the chip.