Abstract: A simplified process and apparatus for electrodepositing a bond-enhancing copper treatment layer on a surface of copper foil, preferably wherein a single treatment layer is uniformly applied on raw copper foil using a current density of from about 40 to about 100 A/ft2, a plating time of greater than 30 seconds, and the electrolyte is a copper sulfate-sulfuric acid solution containing arsenic, chloride ions and 2 imidazalidinethione. The raw foil is transferred to a station for applying the treatment directly from a rotating drum cathode machine on which it is produced, at the same speed at which the raw foil is produced, and then to a barrier layer station, a stainproofing station and a chemical adhesion promoter station, after which it is dried and coiled.

Abstract: An electrolytic process for producing copper foil having a low profile surface exhibiting a high peel strength when bonded to a polymeric substrate, which process comprises: (a) preparing an electrolyte comprising a copper sulfate-sulfuric acid solution, containing as addition agents, a low molecular weight water-soluble cellulose ether, a low molecular weight water-soluble polyalkylene glycol ether, a low molecular weight water-soluble polyethylene imine and a water-soluble sulfonated organic sulfur compound; (b) passing an electric current through the electrolyte from a primary anode to a cathode spaced from the primary anode in a first electrodeposition zone under first mass transfer conditions including a first current density to electrodeposit on the cathode a base copper foil having a fine-grained microstructure and a matte surface having micropeaks with a height not greater than about 150 microinches; (c) passing the base foil and electrolyte from the first electrodeposition zone to a second electrodep

Abstract: A surface of copper foil is protected from oxidation and tarnishing by electrodepositing on the surface a protective layer containing metallic zinc and one or more compound of tri-valent chromium, which protection layer is easily removable by dissolution in a dilute aqueous alkaline solution and which preferably has a zinc to chromium weight ratio of 1:1 or greater. An electrodeposited copper foil especially suited for multilayer printed circuit boards has such a protective layer electrodeposited on the matte side thereof and an electrodeposited copper bonding treatment on the shiny side thereof.

Abstract: A one-step electrolytic process and apparatus for producing metal foil, e.g., copper foil having a low profile treated surface for use in fabricating printed circuit boards, wherein primary foil is electrodeposited on a cathode in a first electrodeposition zone using a first current density while circulating electrolyte therein under turbulent flow conditions, and micronodules of the metal are electrodeposited on a matte surface of the primary foil in a second electrodeposition zone using a second current density greater than the first current density while circulating electrolyte therein under laminar flow conditions. A grain refining agent is employed in the electrolyte to further improve the quality. The process provides a low profile finished foil having a high peel strength.

Abstract: An improved treatment for copper foil comprising electrodepositing a metallic barrier layer of copper, zinc and antimony on at least one side of the foil which, preferably, has a matte surface formed prior to forming the barrier layer. The so-treated foil provides a high bonding strength when laminated to polymeric substrates and resists undercutting by mineral acid etchants and rinses during production of printed circuit boards.