PROCESS FOR THE MANUFACTURE OF HIGH QUALITY VERY LOW PROFILE COPPER FOIL AND COPPER FOIL PRODUCED THEREBY

摘要

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, contaning 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 polyethyleneimine and a water-soluble sulfonated organic sulfur compound; (b) passing an electric current through the electrolyte from a primary anode (31) to a cathode (30) spaced from the primary anode (31) in a first electrodeposition zone under first mass transfer conditions including a first current density to electrodeposit on the cathode (30) a base copper foil (40) 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 electrodeposition zone; and (d) passing an electric current through the electrolyte from a secondary anode (35) to the cathode (30) spaced from the secondary electrode (35) in the second electrodeposition zone under second mass transfer conditions including a second current density greater than the first current density and which provide a mass transfer poorer than that in the first electrodeposition zone, while introducing into the second electrodeposition zone a supplemental stream of the electrolyte, to electrodeposit on the matte surface micronodules of copper.