UV curing is a photochemical process by which monomers undergo curing (polymerization or cross inking) upon exposure to ultraviolet radiation. A specially formulated monomer will polymerize when exposed to ultraviolet radiation. This UV "curable" monomer includes a sensitizer which absorbs UV energy and initiates a polymerizing reaction in the monomer. KW-4AUV is specially designed for curing photosensitive coatings and thin films. It equips two UV light sources with radiations at 365 nm and 245 nm. The coated substrates up to 6?in diameter will be rotated at 6 rpm to ensure uniform curing. The built-in interlock door to prevent the exposure of UV radiation gives safe operation. In conjunction with the KW-4A spin coater, the system can be used to make various coatings and thin films via the photochemical process.