Abstract: A via-filling material improves a via-filling process in manufacturing multi-layered printed circuit boards. The via-filling material is capable of undergoing UV pre-cure and thermal post-cure step. Exposed to ultraviolet light, the via-filling material filled up the two ends of the via form solid barrier films so that the inside via-filling material will not flow out during a thermal post curing process due to an lower viscosity of said material. The dual-cure treatment resolves the problems of polishing, sagging and bubbling in the via-filling process and ensures the integrity of the filling material. As a result, the via-filling material with smooth surface and a solid inside without void or hole therein formed.

Abstract: The present invention relates to a solventless photo-sensitive thermosetting type of material, a method for manufacturing the same, and its use; wherein said solventless photo-sensitive thermosetting type of material mainly comprises an aqueous alkaline-developable photo-sensitive resin, unsaturated monomer(s), epoxy resin(s), photo initiator(s), and is manufactured through a ring-opening condensation reaction as an initiation step, which is characterized in that a photo-sensitive monomer containing an unsaturated bond is used to replace organic solvent(s) regularly used in conventional solder mask products.