| US 7,540,946 B2 | ||
| Plating apparatus | ||
| Shingo Miyata, Tokyo (Japan); and Atsushi Yamaguchi, Tokyo (Japan) | ||
| Assigned to TDK Corporation, Tokyo (Japan) | ||
| Filed on Feb. 15, 2006, as Appl. No. 11/354,156. | ||
| Claims priority of application No. 2005-080261 (JP), filed on Mar. 18, 2005. | ||
| Prior Publication US 2006/0207874 A1, Sep. 21, 2006 | ||
| Int. Cl. C25D 21/00 (2006.01) | ||
| U.S. Cl. 204—228.8 [204/229.9; 204/196.01; 204/196.11; 204/230.1; 204/230.7] | 4 Claims |
| 1. A plating apparatus comprising:
a power supply for generating a voltage between a pair of terminals;
an anode connected to one of the terminals of the power supply;
a main cathode connected to the other terminal of the power supply while in contact with a substrate;
an auxiliary cathode connected to the other terminal of the power supply while out of contact with the substrate;
a main resistance connected in series between the other terminal of the power supply and the main cathode; and
an auxiliary resistance connected in series between the other terminal of the power supply and the auxiliary cathode;
wherein the main cathode has an annular form and is in contact with a peripheral part of the substrate;
wherein the auxiliary cathode has an annular form and opposes the main cathode;
wherein an insulating layer is provided between the main and auxiliary cathodes;
wherein an outer diameter of the auxiliary cathode is larger than an outer diameter of the main cathode;
wherein the auxiliary cathode includes a protruding part projecting in a radial direction beyond an outer face of the main
cathode, the insulating layer covering a portion of a surface of the protruding part, the insulating layer projecting from
the auxiliary cathode in the radial direction beyond an outer face of the auxiliary cathode.
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