Abstract: Disclosed is an aqueous chromium deposition solution containing chromium in the trivalent state, from which a bright decorative chromium plate can be advantageously formed. The chromium deposition solution contains (a) a water-soluble trivalent chromium salt; (b) at least one compound selected from unsubstituted and amino- or hydroxy-substituted carboxylic acids and salts thereof; (c) a water-soluble aluminum salt, and; (d) ammonium ion.

Abstract: A process is disclosed for preventing oxidative coloring while maintaining good solderability of copper foil wherein a thin layer of tin or a combination of tin and zinc alloy is electro-deposited on the surface of the shiny side of copper foil and the tin or binary alloy diffuses into the surface portion of electrodeposited copper foil by heating, such as drying, baking or lamination under heat and pressure. By virtue of an extremely thin layer of the tin alloy thus formed, the bright tone of the copper surface is maintained during storage or during subsequent lamination of the foil, and the solderability thereof is also improved.

Abstract: The present invention relates to a method of treatment on the surface of copperfoil mainly used for printed circuits. More particularly, it relates to a method of electrodeposition of a binary alloy consisting of zinc and tin as a barrier layer against copper migration into an adhesive substrate during subsequent heat press lamination, while a binary alloy on copperfoil is converted to ternary alloy defusing into copper by heat press lamination resulting in a layer of Cu-Zn-Sn, ternary alloy. This layer prevents spottings on the etched surfaces and provides high resistance to hydrochloric acid, and better adhesion than hitherto used alloys.

Abstract: A copper foil having high bond strength with an insoluble particle-containing metal plate formed thereon, the plated copper foil being adapted for use in the preparation of, for example, a printed circuit.