Surface treatment method of copperfoil
AssigneeMitsui-Anaconda Electro Copper Sheet Co., Ltd.
InventorShigeyoshi Morisaki
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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.
Claims5
A method for surface treatment of copper foil used for printed circuit boards comprising the steps of subjecting a nodularized surface of copper foil to electrodeposition thereon of a thin layer of zinc and tin alloy in which the tin content is from about 5 to 20%, and at a thickness of from 0.03.mu. to 0.15.mu., and adhering the alloy-covered surface of the nodularized copper foil thus obtained to a resinous laminate by heat and pressure until a layer of a ternary alloy of zinc, tin and copper is formed between said copper foil and said resinous laminate.
Dependencies are inferred from the claim text.