Micro Probe Produced by 3D-Processing using Synchrotron Radiation

Abstract

The rapid microminiaturization of LSI chips has encouraged the need for similarly microminiaturizing the probes of probe cards, the parts used to inspect IC chips. In response to this need, a method of producing 3-dimensional microprobes is devised by etching a substrate in advance and then performing X-ray lithography. By examining and optimizing each part of the process, we produced a 3-dimensional microprobe with the desired shape. The microprobe was 18 μm wide and 50 μm thick, with a tip 185 μm high, consisting of both the spring part and the tip. The mechanical and electrical properties of the microprobe were estimated by measuring the contact force and contact resistance. The measurement showed satisfactory results: the contact force allowed a displacement magnitude as large as 80 μm, accompanied by a satisfactory contact force of 0.39 gf. In addition, the contact resistance exhibited low and stable values when contact was formed on an object made of Au exhibiting a contact force of 0.1 gf or more, demonstrating the high potential of the prototyped microprobes.