PROPERTIES OF A UV-CURABLE, DURABLE PRECISION ADHESIVE

We have developed a precision adhesive that is UV-curable and durable and has low shrinkage during curing and a low coefficient of thermal e xpansion. This new adhesive consists of a cycloaliphatic diepoxy aceta l, a triarylsulfonium-SbF6, an epoxy silane coupling agent and a synth etic cordierite filler. With an optimized amount of filler, this adhes ive can be cured completely in about five minutes with less than 2% sh rinkage by exposure to UV irradiation. The cured adhesive exhibits a l ow coefficient of thermal expansion of less than 2 x 10(-5)/degrees C, high glass transition temperatures of 200 degrees C, and excellent du rability in boiling water and moisture. Thus, the adhesive can replace welding in the fabrication of optical components that require sub-mic rometer positioning accuracy.