The invention is directed to an improved lamination process of a photopolymerizable film onto a substrate employing a liquid which is present during the application of film to the substrate.
Lamination of a photosensitive material onto a substrate employing an intermediate liquid layer is taught in several U.S. patents using various liquids and application techniques. U.S. Pat. No. 3,629,036 discloses application of a liquid adhering agent, preferably a solvent for a resist containing a small amount of dissolved resist, to a surface of a substrate followed by application of a photosensitive resist film. U.S. Pat. No. 4,069,076 discloses a process for applying a photoresist film to a preimaged pattern relief substrate after flooding the substrate with a solvent or a nonsolvent swelling agent. U.S. Pat. No. 4,293,635 discloses application of a photosensitive composition containing an amphoteric interpolymer to a copper surface wetted with a liquid such as an ethanol-water solution.
U.S. Pat. No. 4,506,004 discloses various embodiments of obtaining printed wiring boards by means of a two layer composite coating. In one embodiment an adhesive photopolymer layer is applied to a printed wiring board in a liquid state displacing air from the printed wiring board surface. A dry film solder mask is temporarily adhered to the underside of a screen printing frame and applied onto the liquid layer prior to processing of the photopolymer layer. In another of the embodiments of the patent nonphotoimaging epoxy layers can be employed.
USPTO Backgrounds
USPTO Backgrounds