Development of an electrostatically actuated MEMS switching probe card

Abstract

We have designed and fabricated a new type of MEMS probe card consisting of electrostatically-driven microprobes, which can be used for a next generation wafer probe card with the fritting-contact method. MEMS probe cards are requisite to higher pad-density and smaller pad-pitch chips, and are effective in high frequency testing. If a probe card consists of an array of actuator-integrated microprobes, it could be suitable for a wafer-level test/burn-in probe card, since the microprobes can be used for direct switching of the contact to reduce the number of the I/O lines of the probe card. We proposed a MEMS probe card that is composed of an array of Ni curl-up microcantilevers with a rolling-contact touch-mode electrostatic actuator and developed a micromachining process which includes electroplating deposition of two layers having different internal stress and etching of Al sacrifice layer. By measuring the electrostatic actuation properties and investigating the disconnection force of the fritting contact between a Ni probe and Al film, it has been found that the fritting contact could be disconnected by applying the voltages less than 100 V.