Patent ID: 8250751
Filing Date: 2012-08-28
Classification: H05K,Y10T

Abstract:
1. A method of manufacturing a printed circuit board having a plurality of circuit layers with at least one through-hole to connect copper patterns on different layers of the printed circuit board, the method comprising: drilling at least one through-hole into a laminated structure with a first solid copper layer and a second solid copper layer respectively as both outermost layers of the laminated structure; metalizing the drilled circuit layers with the at least one through-hole; applying a resist on both outermost layers of the circuit layers; patterning the resist on both outermost layers of the circuit layers to expose the at least one through-hole to an electrolytic plating solution; electrolytic copper plating the at least one through-hole with the electrolytic plating solution to fill close the at least one through-hole with copper; removing the resist; planarizing excess copper plated on both outermost layers of the circuit layers to expose both outermost layers of the circuit layers; cleaning the planarized circuit layers with the copper filled through holes; applying a second resist on at least one outermost layer of the outermost layers with the copper filled through-hole; patterning the second resist on the at least one outermost layer to image a conductive cap on the copper filled through-hole; and plating copper directly on the copper filled through-hole to form the conductive cap.