Patent ID: 7404908
Filing Date: 2008-07-29
Classification: H01B,H05K,Y10T

Abstract:
1. A printed wiring board manufacturing method comprising the steps of: (a) making a large number of through-holes in a laminated sheet coated with copper, said laminated sheet having first and second sides and said through holes having through-hole interior surfaces; (b) making the through-hole interior surfaces electrically conductive; (c) coating the copper on the first side of the laminated sheet with a photosensitive dry film having an outer masking layer attached thereto; (d) allowing a developing solution to infiltrate into the through-holes from the second side; (e) developing the photosensitive dry film as a plating resist for hardening, said photosensitive dry film being developed in an area of outer peripheries of said through holes on said first side of the laminated sheet; (f) removing the outer masking layer; (g) copperizing the through-holes and the outer peripheries thereof; (h) removing the photosensitive dry film; and (i) forming a circuit pattern.