Transferrable fine pitch probe technology

Abstract

Two vertical probe technologies were explored to evaluate wafer-level and 3D stack-level die test at 50 μm pitch. In one approach, Cu probe tips were serially built on a 3D silicon wafer using lithography and wet chemical etching. In a second approach, metal probe tips were fabricated by filling a silicon mold made with anisotropic etching and transferred to a silicon die. Each approach had advantages which were demonstrated through test vehicles. The second approach appears promising to offer a robust, scalable probe technology, highly suited for high speed test of 3D die. As compared to traditional probe technologies, this approach also offers an opportunity toward low cost test at fine pitch.