Patent ID: 10815389

Abstract:
A photosensitive and via-forming circuit board comprising a laminate unit, a conductor unit, and a cover layer unit is provided. The laminate unit includes an insulating layer, a first conductive wiring layer and a second conductive wiring layer formed at two opposite sides of the insulating layer, respectively, and at least one through-hole surface defining a through hole extending from the upper surface of the first conductive wiring layer through the insulating layer to the lower surface of the second conductive wiring layer. The conductor unit is formed on the at least one through-hole surface. The cover layer unit is formed from a photosensitive composition comprising an epoxy group-containing compound and a photosensitive polyimide capable of reacting with the epoxy group of the epoxy group-containing compound, and includes a first cover layer formed on the first conductive wiring layer and extending into and filling the through hole.