Copper plating bath and process for difficult to plate metals

Claim 2

An acid copper plating bath for electropositive metals consisting essentially of: 0.5 to 0.75 mols per liter sulfuric acid, 0.3 to 0.5 mols per liter hydrated copper sulfate, 1 to 2 grams per liter, urea, 1 to 2 milliliters per liter, wetting agent, 1 to 2 grams per liter, Beta-phenylethyltosylate as a brightening agent, and sufficient deionized water to make one liter.

Claim 3

The bath of claim 1 wherein the wetting agent is a cationic surfactant.

Claim 4

An aqueous acid copper electroplating bath composition for strongly electropositive metals such as aluminum and tungsten comprising: sulfuric acid, 30-50 grams/liter; hydrated copper sulfate, 50-72 grams/liter; urea, 1 gram/liter; Beta-phenylethyltosylate, 1 gram/liter; and cationic surfactant, 1 gram/liter.

Claim 5

An aqueous acid copper electroplating bath composition for strongly electropositive metals such as aluminum and tungsten comprising: sulfuric acid, 30-50 grams/liter; hydrated copper sulfate, 50-72 grams/liter; urea, 1 gram/liter; Beta-phenylethyltosylate, 1 gram/liter; and cationic surfactant, 1 gram/liter.

Claim 6

A process for copper plating electropositive metals comprising the steps of: A. preparing a bath containing 0.5 to 0.75 mols per liter sulfuric acid, 0.3 to 0.5 mols per liter hydrated copper sulfate, 1 to 2 grams per liter, urea, 1to 2 milliliters per liter, sodium lauryl sulfate, 1 to 2 grams per liter, a tosyl or mesyl sulfonic acid ester, and sufficient deionized water to make one liter by first mixing components in order set out then filtering the solution; B. soaking the parts to be plated in the bath for 2 to 3 minutes; and C. electrodepositing copper from the bath, at a temperature of about 20 to 30 degrees centigrade, at a current density of 10 to 20 amperes per square foot, with continuous agitation.

Claim 7

A process for copper plating electropositive metals comprising the steps of: A. preparing a bath containing 0.5 to 0.75 mols per liter sulfuric acid, 0.3 to 0.5 mols per liter hydrated copper sulfate, 1 to 2 grams per liter, urea, 1to 2 milliliters per liter, sodium lauryl sulfate, 1 to 2 grams per liter, a tosyl or mesyl sulfonic acid ester, and sufficient deionized water to make one liter by first mixing components in order set out then filtering the solution; B. soaking the parts to be plated in the bath for 2 to 3 minutes; and C. electrodepositing copper from the bath, at a temperature of about 20 to 30 degrees centigrade, at a current density of 10 to 20 amperes per square foot, with continuous agitation.

Claim 8

The process of claim 4 wherein the soaking step is replaced by soaking for 30 to 60 seconds, under the influence of a positive bias.