Fabrication of sharp knife-edged micro probe card combined with shadow mask deposition

We introduce a micro-machined cantilever type probe card with a special tip shape made of single crystal silicon. A novel process for the micro-machined probe card with a sharp tip formation was developed and micro probe arrays of 40μm in pitch were also realized. Probe cantilevers including the sharp tip were formed with anisotropic KOH etching and LOCOS, and thermally deposited with chrome (Cr) and gold (Au). In the final post-process, the tip area of the realized probes was covered with hard material like tungsten (W) using a micro-machined shadow mask. This probe could endure considerable force because both the tip and cantilever were entirely fabricated from single crystal silicon, and the shape of the sharp probe tip was specifically fabricated to break the oxidized surface of the IC chip with ease. This probe is also expected to have a long life-time and sufficient tip hardness since the end of the tip is coated with hard metal.