Methods of cleaning copper surfaces in the manufacture of printed circuit boards
OwnerYing Ding, Ronald N. Redline +2inventors
InventorsYing Ding, Ronald N. Redline, Richard C. Retallick, Mark Wojtaszek
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Abstract
The present invention sets forth an improved method of microetching a metal substrate by contacting the substrate with an aqueous composition comprising a sodium persulfate or hydrogen peroxide oxidizing agent, acid, and one or more additives. When the oxidizing agent is sodium persulfate, the one or more additives generally comprise an aliphatic saturated dicarboxylic acid. When the oxidizing agent is hydrogen peroxide, the one or more additives generally comprise a stabilizer and amino tris(methylene phosphonic acid).
Claims13
A process for the manufacture of a printed circuit board comprising conductors comprised of copper and non-conducting material, said process comprising:
- (a) contacting said printed circuit board with a dispersion comprising carbon particles;
- and
- (b) contacting the printed circuit board with an aqueous microetchant comprising:
- (i.) sodium persulfate;
- (ii.) acid;
- and
- (iii.) one or more aliphatic saturated dicarboxylic acids;
- such that the carbon particles are substantially removed from the conductors but the carbon particles substantially remain as a coating on the non-conducting material.
A method of microetching a metal substrate by contacting the substrate with an aqueous composition consisting essentially of:
- (a) sodium persulfate;
- (b) an acid;
- and
- (c) an aliphatic saturated dicarboxylic acid;
- and
- (d) copper sulfate.
Dependencies are inferred from the claim text.