US 5,628,892 AGranted

Electroplating method and apparatus for the preparation of metal foil and split insoluble electrode used therein

AssigneeTDK Corporation

InventorsYukio Kawashima, Kazuhide Ohe, Hiroyuki Nakada

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Abstract

A length of electroplated metal foil, typically copper foil is prepared by placing a stationary arcuate anode concentrically with a rotating cathode drum to define a channel therebetween, passing a plating solution through the channel, conducting electricity across the channel for depositing metal on the cathode drum, and separating the metal deposit from the cathode drum. The anode includes a plurality of circumferentially arranged electrode segments formed of a valve metal material and coated with a platinum group metal or oxide thereof. The electrode segments are removably attached and electrically connected to a back plate. The split anode is easy in assembly and disassembly and, hence, in maintenance and repair, has a high degree of precision in configuration and dimensions, and ensures manufacture of copper foil of quality with a minimized variation in thickness during continuous operation.

Claims16

Dependent claims

An electroplating apparatus comprising:

a cathode drum adapted to rotate about an axis;
a split insoluble electrode which forms a stationary anode disposed concentrically around the cathode drum to define a channel therebetween, said electrode having a radius of curvature of 500 to 2,000 mm, said anode including a plurality of circumferentially arranged adjacently disposed arcuate electrode segments which define a substantially continuous smooth curvilinear surface, said curvilinear surface having a arc component of a cylinder and extending parallel to said axis, said electrode segments are made of a valve metal material coated with a platinum group metal or an oxide thereof, said anode further including a single conductive back plate of corrosion resistant conductive metal and conductive fixtures for removably attaching said electrode segments to said back plate, each of said electrode segments are positioned adjacent to said back plate and have a first surface which face said cathode drum and a second surface opposed to said first surface which face said back plate, a spacing between said anode and the cathode drum being 5 mm or less, said back plate comprising apertures through which said conductive fixtures extend such that a first end of each of said conductive fixtures are fixed to said second surface of said electrode segments;
attachment means removably positioned on a second end of each of said conductive fixtures for removably attaching each of said electrode segments to said back plate;
means for supplying an electroplating solution containing a metal to the channel between the cathode drum and the anode;
means for conducting electricity between the cathode drum and the anode for depositing the metal on the cathode drum;
means for separating the metal deposit from the cathode drum to obtain a length of electrolytic metal foil having a thickness of up to 70 .mu.m;
and
an insulating rubber sheet interposed between said electrode segments and the back plate;
wherein the electrode segments on their arcuate surface are separated from each other by a distance of 0.1 to 5 mm.

6 more elements

An electroplating method comprising the steps of:

adjacently disposing a plurality of arcuate electrode segments of a valve metal substrate coated with a platinum group or an oxide thereof to define a substantially continuous smooth curvilinear surface;
removably attaching and electrically connecting said plurality of electrode segments on a single conductive back plate of corrosion resistant conductive metal to form a stationary anode which defines a split insoluble electrode, said electrode having a radius of curvature of 500 to 2,000 mm;
placing a rotating cathode drum and said stationary anode at a spacing therebetween such that a facing surface of each of said electrode segments opposite an underside surface faces said cathode drum, said spacing being 5 mm or less and said stationary anode is disposed around and concentrically with the cathode drum;
providing an electroplating solution containing a metal between said cathode drum and said anode;
conducting electricity between said cathode drum and said anode for depositing the metal on said cathode drum;
and
separating the metal deposit from said cathode drum to obtain a length of an electrolytic metal foil having a thickness of up to 70 .mu.m;
said removably attaching and electrically connecting step comprising the steps of:
passing fastening means through apertures in said back plate in a direction toward said electrode segments and fixing one end of said fastening means to said underside surface of said electrode segments;
and
removably attaching an attachment means onto a second end of said fastening means to permit removable attachment of said plurality of electrode segments to said back plate;
wherein said electrode segments on their surface facing the cathode drum are separated from each other by a distance of 0.1 to 5 mm.

9 more elements

Dependencies are inferred from the claim text.