Importance

Loading Importance Indicators...

Abstract

An improvement to the process for electroplating a conductive metal layer to the surface of a non-conductive material which comprises: (a) contacting said printed wiring board with an aqueous polyelectrolyte homopolymer conditioner solution having a charge density from about 0.2 to about 2.5 milliequivalents (positive charge) per gram of dissolved polymer and having a pH in range from about 3 to about 5, followed by; (b) contacting said printed wiring board with a dispersion of carbon black comprising: (1) carbon black particles having an average particle diameter of less than about 3.0 microns in said dispersion; (2) an effective dispersing amount of a surfactant which is compatible with said carbon black; and (3) liquid dispersing medium, wherein the amount of carbon black is sufficient to coat substantially all of said non-conducting surfaces and is less than about 4% by weight of said liquid dispersion; then (c) separating substantially all of the liquid dispersing medium from said dispersion, thereby depositing said applied carbon black particles in a substantially continuous layer on said non-conducting portions of said hole walls; and (d) electroplating a substantially continuous conductive metal layer over the deposited carbon black layer and said non-conductive surface, thereby electrically connecting said metal layer of said printed wiring board.

Loading the Abstract Image...

First Claim