Head Member For A Current Bar For Use In Electroplating Apparatus

Abstract

Method and apparatus for reducing corrosion of a current bar in a corrosive environment. The non-reactive metal is fused around a reactive metal creating a shell and reducing the corrosion of the reactive metal.

Description

CROSS REFERENCE TO RELATED APPLICATION

The present patent application is based upon and claims the benefit of provisional patent application No. 61/644,500, filed on May 9, 2012.

The present invention is intended for use with an electroplating apparatus intended to metal coat substrates of various types. The invention is specifically directed toward an improved head member for a current bar for use in providing electrical current to an anode and returning electrical current to a power supply from a cathode or substrate.

BACKGROUND OF THE INVENTION

In a typical electroplating process a power source having an anode and a cathode is engaged with current bars. The current bars are immersed in a plating bath. The current bars supply current from the power source to an anode and returns current to the power source via the substrate to be coated or cathode. Many times current bars are constructed of copper as copper has proven to be highly efficient in transporting electrical current. The plating bath many times is of varying acidity and composition depending upon the specific metal being applied to the substrate. Typical metals used as coatings includes iridium, nickel, copper, tin, zinc, chromium, gold, silver, palladium, and platinum.

The acidity of the plating bath is known to react with the copper of the current bar and very rapidly decomposes the current bar, resulting in increased maintenance and time consuming and costly replacement of the current bar. Past attempts to protect the copper of the current bar include wrapping the current bar with a metallic outer shell wherein the metallic outer shell is non-reactive with the acidic plating bath. Problems continue to be encountered however when the current bar is immersed in the plating bath and acid seeps between the outer wrap and the copper current bar. The current bar includes an unwrapped head member having exposed copper where the current bar is engaged to the power source. Thus, the gap between the copper and the metal wrap is exposed to the chemicals in the plating bath. The chemicals then seep into the gap along the entire length of the current bar. The present invention improves upon this structure for the current bar.

DESCRIPTION OF THE INVENTION

The present invention provides a head member for a current bar that is constructed of copper fused with a non-reactive metal, such as titanium. The fusing of the metal shell to the copper eliminates the gap between the shell and the copper which previously allowed the acid in the tanks to seep into the gap between the copper and the shell and erode the copper, thus ruining the current bar. The copper head member clad in titanium provides a sealed unit, when properly attached to the current bar, which blocks the acid from seeping between the copper and the titanium, resulting in slower erosion of the current bar.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of the current bar of the present invention.

FIG. 2 is a top view of the current bar head of the current bar of FIG. 1.

FIG. 3 is a side view of the current bar head of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIG. 1 a current bar 10 is shown, the current bar is composed of an L-shaped section which is used to carry the metal anode plate (not shown). The current bar is preferably constructed of copper whose outer surface is fused with a titanium layer. The metal anode plate is attached to the current bar by fasteners extending through holes 14. The current bar includes a head member 16 which attaches directly to the power supply.

Referring now to FIGS. 2 and 3 the head member 16 is constructed of copper fused with titanium. Contact face 18 is created by machining the titanium from the copper and exposing the copper. Holes 20 machined in the current head allow a fastening member to attach the head member 16 to the power supply wherein the contact face 18 receives the electrical charge and transports it through the copper of the current bar 10. End 22 of the head member 16 also has the titanium clad machined therefrom. The head member is thus allowed to be welded to the current bar 10, first through a copper to copper weld, and secondly through titanium weld. Thus, the entire current bar 10 is sealed from seepage of the acidic chemicals from the plating bath through the head member 16. The copper, with the exception of the machined face of the head member 16, is not exposed to the chemical plating bath. In this embodiment the opposed end 24 has a titanium end cap welded to prevent exposure of the copper material to the acid bath. Thus, the invention creates a sealed unit in which the acid chemicals cannot get between the copper material and the titanium shell and erode the existing current bar 10. If the exposed copper on the head member 16 erodes, the head member is easily removed from the current bar 10 and a replacement head member can be welded thereto. This eliminates salvaging costs for the entire current bar.

While copper fused with titanium are the preferred metals for forming the current bar, those metals are not intended to exclude the use of other metals capable of achieving the desired results. This description of the preferred embodiment is not intended to limit the scope and context of the following claims.

The above Detailed Description Of The Present Invention is given for explanatory purposes. It will be apparent to those skilled in the art that numerous changes and modifications can be made without departing from the scope of the invention. Accordingly, the whole of the foregoing description is to be construed in an illustrative and not a limitative sense, the scope of the invention being defined solely by the appended claims.

Claims

1. An apparatus for conducting a current and reducing erosion comprising a conductive metal fused with a non-reactive metal.

2. An apparatus according to claim 1 wherein the conductive metal is copper.

3. An apparatus according to claim 1 wherein the non-reactive metal is titanium.

4. An apparatus according to claim 1 wherein the conductive metal has an outer surface and the non-reactive metal creates a shell fused with the outer surface of the conductive metal.

5. An apparatus according to claim 1 wherein the combination of the fused non-reactive metal to the conductive metal reduces corrosion of the conductive metal in a corrosive environment.

6. An apparatus according to claim 1 wherein a portion of the non-reactive metal shell is removed from the outer surface exposing the conductive metal for connecting with a power source

7. A method for replacing a corroded metal head comprising:

removing the metal head from the current bar;

attaching a new head member to the existing current bar by first welding the conductive metal of the head member to the conductive metal of the current bar, using a conductive metal to weld the members; and

welding the non-reactive metals of the head member to the non-reactive metal of the current bar using a non-reactive metal for said welding.

8. A method for reducing corrosion in a current bar immersed in a corrosive environment comprising:

a) fusing a conductive metal member with a non-reactive metal shell eliminating any exposed surface of the conductive metal;

b) creating an exposed surface of the conductive metal member to form a head member;

c) connecting the exposed surface of the metal head member with a power source;

d) operating the current bar in a corrosive environment.