The standard brings requirements for electrodeposited coatings of copper used for engineering purposes. Examples include surface hardening, heat treatment stop-off, as an underplate for other engineering coatings, for electromagnetic interferences (EMI) shielding in electronic circuitry, and in certain joining operations.
Copper is used as a strike to improve adhesion of the plated deposit to the substrate as well as an inexpensive barrier coat between brass substrates and a tin or tin lead deposit. The zinc in the brass likes to migrate into tin and tin lead deposits used in the electronic industry. A copper barrier coat of no less than .000050 inches tends to slow down the migration of the zinc into the final deposit which will greatly improve the shelf life of a product, especially if future solderability is required. It should be noted that the best barrier coat for shelf life purposes would be a watts or sulfamate nickel deposit of no less than .000050 inches. Since nickel has a much tighter grain structure than copper, it can hold off the zinc migration 10 times longer than a copper barrier coat.
Are widely used in the area of printed circuits, electronics, rotogravure, plating on plastics, decorative copper and electroforming applications. While the deposit of copper from and acid based electrolyte is often more efficient, less expensive and easier to waste treat and other alkaline solutions, it too has it draw backs. Most importantly, steel parts must be plated with a cyanide copper or a nickel strike to prevent immersion copper from forming on the substrate. This will cause a very poor bond between the base metal and the acid copper deposit that will blister or peel causing a reject.