Curing of sealants using multiple frequencies of radiation

Abstract

A system using several wavelengths, preferably from the output of a single laser, is described for curing a dual cure glue seal that affixes two substrates to form a liquid crystal display panel. Here the liquid crystal is already in place before the glue seal is cured so that a high temperature bake to promote the sealant curing is not permissible . The multiple wavelengths from the single source of radiation result both from frequency doubling and mixing of the fundamental laser to achieve frequency tripling. Generally a UV wavelength is required for curing the photolytic component of the glue seal so that in the present invention the fundamental from a ˜1 micron (1000 nm) wavelength laser is frequency tripled. The UV is scanned along the entire peripheral region of the glue seal. The other wavelengths, typically infrared and possibly the first frequency doubled (first harmonic) of the infrared are separately collected and separately scanned only along those regions of the glue seal shadowed by circuit lines. These wavelengths are partially absorbed by the metal lines to cause thermal initiation of the dual component glue seal which is used in such a system.

Dependencies are inferred from the claim text.