A Novel Wet Etch In-situ Decapsulation of Devices on Boards

This paper presents a novel technique for decapsulation of integrated circuits (ICs) mounted on printed circuit boards. This technique overcomes wet etch related sidewall blowouts that damage or alter the performance of the IC and board under test. It also allows well defined etch geometries and better endpoint detection. This is accomplished by protecting the region of interest (ROI) with a fast-curing, acid-resistant maskant that peels off easily. The technique was successfully utilized on a densely populated board, which exhibited temperature sensitive failure mechanism, as discussed in this paper.