Patent attributes
The present invention provides a method of manufacturing a printed circuit board, which includes preparing a dielectric substrate, coating surfaces of the dielectric substrate, filling a via hole with a conductor, peeling mold-releasing films, compressing the dielectric substrate and forming metal foils. The dielectric substrate has patterned wiring layers on both surfaces, and the wiring layers are connected electrically with each other by the conductor. The dielectric substrate is made of a glass cloth or a glass nonwoven fabric impregnated with a thermosetting epoxy resin mixed with fine particles, and the conductive filler in the conductor has an average particle diameter larger than that of the fine particles. Accordingly, the printed circuit board has an improved moisture resistance as a whole and also excellent connection reliability and repair resistance. In addition, the dielectric substrate of the printed circuit board has an improved mechanical strength such as flexural rigidity.