Fabrication of micro-probe beam using MEMS technology for new vertical silicon probe card

This paper presents the new wafer probe card technology with 40 pm pitch and 605 pads by MEMS technology. We have fabricated a micro-probe beams using porous silicon micromachining, RIE (reactive ion etching), and electroplating process. In order to form electroplating mold, we used a thick negative SU-8 photoresist. To use probe beams as tip of probe card, their thermal and mechanical properties was investigated. Probe beams are curled up as a result of surface tension and difference in the thermal expansion coefficients between the thin films on the beams.