A thermomechanical relay with microspring contact array

Abstract

A micromachined thermomechanical relay with Au microspring contact array is presented. Thermally excited Al-SiO/sub 2/ bimorph cantilevers have been fabricated with micromachining technology. Sputtered Au/Pt/Ti contacts are formed on the tip of the cantilevers and microheaters are built in the cantilevers. In order to reduce the ON-resistance and to avoid the metallic binding between Au contacts, Au microspring contact array is fabricated on Pyrex glass. The fabricated thermomechanical microrelay is operated with input power levels ranging from 20-80 mW at frequencies up to 3 kHz. The ON resistance R/sub ON/, that includes contact resistance and signal line resistance is in the range of 200-500 m/spl Omega/ and switching time is about 300 /spl mu/sec. 10/sup 7/ cycles operation has been performed keeping the R/sub ON/ around 300 m/spl Omega/.