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Publication numberUS3862891 A
Publication typeGrant
Publication dateJan 28, 1975
Filing dateSep 24, 1973
Priority dateSep 24, 1973
Publication numberUS 3862891 A, US 3862891A, US-A-3862891, US3862891 A, US3862891A
InventorsEugene C Smith
Original AssigneeGte Automatic Electric Lab Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Uniform plating current apparatus and method
US 3862891 A
Abstract
A uniform plating current apparatus and method for providing a nearly uniform flow of plating current within a plating tank containing plating solution between a work piece to be plated and an anode surface.
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Description  (OCR text may contain errors)

United States Patent. 1191 Smith 1 Jan. 28,1975

1 1 v UNIFORM PLATING CURRENT APPARATUS AND METHOD [75] Inventor: Eugene C. Smith, Elk Grove Village, 111.

731 Assignee: GTE Automatic Electric Laboratories Incorporated, Northlake, 111.

[22] Filed: Sept. 24, 1973 [211. Appl. No.: 399,894

[52] U.S. Cl 204/27,204/279, 204/D1G. 7 [51] Int. Cl C23b 5/58, B01k 3/00 [58] Field of Search 204/297 W, D16. 7, 15.

[56] References Cited UNITED STATES PATENTS 1,519,572 12/1924 Wolf 204/D1G. 7

2,675,348 4/1954 Greenspan 204/297 2,751,340 6/1956 Schaefer 204/23 2,859,166 11/1958 Grigger 204/279 FORElGN PATENTS OR APPLICATIONS 986 ""1896 Great Britain ..204/1)10.7 587,445 3/1931 Germany "204/0107 Primary Examiner-J. M..Tufariello Attorney, Agent, or Firm.1amcs V. Lapacek 1 ABSTRACT A uniform plating current apparatus and method for providing a nearly uniform flow of plating current within a plating tank containing plating solution between 21 work piece to be plated and an anode surface.

6 Claims, 7 Drawing Figures PATENTEU JAN 2 81975 SHEET 1 OF 3 METHOD BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to the field of electroplating and more particularly to a new and improved uniform plating current apparatus and method.

2. Description of the Prior Art In the plating of objects, particularly where the objects have a large surface area orwherein a large number of components are plated simultaneously in a single plating rack, the uniformity of the plating thickness is difficult to control. The plating thickness is especially important when plating such objects as reed blades for reed relay capsules. The plating thickness distribution in the electroplating process is a function of the plating current that each particular component or portion of the object to be plated receives from the anode. Uniformity of current flow and preventing extraneous currents flowing near the periphery of the work piece is essential where equal plating thickness is required. A variety of approaches have been attempted in order to eliminate unequal plating distribution utilizing shields and robber or thief elements to absorb the extraneous current flows. Typical of a shielding arrangement near the object to be plated is that described in Us. Pat. No. 2,675,348 which issued to L. Greenspan on Apr. 13, 1954. Shielding means in order to affect uniform plating is also described in U.S. Pat. No. 2,859,166which issued to J. C. Grigger onNov. 4, 1958. A method and apparatus for obtaining uniform plating on the bearing surfaces of semi-cylindrical flanged bearings by the use of shields or baffles positioned between the bearing and a slot communicating with the anode is described in US. Pat. No. 2,75l,340 which issued to R. A. Schaefer et al. on June 19, 1956. The various attempts to obtain uniform plating by means of shields and thief or robber elements are not desirable where an extremely high degree of uniformity over a large plating rack or object is desired. Uniform plating methods utilizing shields cause blockage of the natural flow of electrolyte solution with resultant turbulence effects which disturbs uniformity of plating distribution. Further shielding techniques of the prior art are very critical in their placement due to the fact that shielding very near the surface of the object to be plated causes complex current flow patterns which are difficult to measure and maintain.

OBJECTS AND SUMMARY OF THE INVENTION Accordingly it is a principal object of the present invention to provide a uniform plating current apparatus and method for providing a nearly uniform flow of plating current to obtain a uniform plating distribution (throughout) the surface area of a plating rack.

Another object is a uniform plating current apparatus that provides unrestricted flow of the electrolyte solution in a plating tank thereby eliminating turbulence conditions affecting the plating process.

These and other objectives of the present invention are achieved by providing two generally parallel surfaces of nonconductive composition positioned along two sides of the anode surface that extend upwardly from the anode to the plating rack area or object to be plated. Further the apparatus comprises a first and sec- 0nd plurality of flow-blades running transversely between the parallel surfaces and generally along the opposite edges of the anode surface. The flow-blades are spaced one above the other along the distance between the anode surface and the plating rack area or object to be plated.

Other objects will appear from time to time in the ensuing specification drawings and claim.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the uniform plating current apparatus of the present invention;

FIG. 2 is a front view of a plating tank in which no means is provided for uniform current flow;

FIG. 3 is a front view of a plating tank in which two shields or surfaces have been provided to obtain uniform current flow;

FIG. 4 is a front view of a plating tank in which flowblades similar to the present invention have been provided in order to obtain uniform current flow;

FIG. 5 is a front elevational view of the plating apparatus of the present invention;

FIG. 6 is a plan view of the apparatus shown in FIG. 5; and

FIG. 7 is a side elevational view of the apparatus in FIG. 5.

DESCRIPTION OF PREFERRED EMBODIMENT The uniform plating current apparatus of the present invention illustrated in FIGS. 1, 5, 6 and 7 includes a front retaining wall 10, a rear retaining wall 12, side walls 14 and 16 and a base 18. Each of the side walls 14 and 16 includes a rectangular opening bounded by edges 20, 22 and 24 as best shown in FIG. 7. Flowblades 26, 28, 30 and 32 are carried by each of the side walls 14 and 16 and by the front retaining wall 10 and the rear retaining wall 12. The flow-blades 26, 28, 30 and 32 may be secured by means of slots in the material of the side wall l4, l6 and front retaining wall 10 and rear retaining wall 12 and/or by means of cement. The flow-blades, as best shown in FIG. 5, are rectangular sheets of varying lengths with the top flow-blade 26 mounted nearest the upper most portion of the side walls 14 and 16 being the shortest in length or overhang and each successive flow-blade 28, 30 and 32 being each of successively increasing length over the preceding flow-blade. The leading edge or tip 34 of each of the flow-blades 26, 28, 30 and 32. is generally beveled or V-shaped. The function and purpose of the leading edge 34 will be explained in detail hereinafter.

Two plating rack guide pieces 36 are each mounted on the upper mosr edge of the front retaining wall 10 and the rear retaining wall 12 whose function will be explained in detail hereinafter. The guide pieces 36 are mounted to the front and rear retaining walls 10 and 12 by means of screws 38 although they may also be cemented. Similarly the front retaining wall 10, the rear retaining wall 12, the side walls 14, 16 and the base 18 may be secured by screws or otherwise bonded together such as by means of cement. The uniform plating current apparatus including walls 10, 12, 14 and 16 base 18, flow-blades 26, 28, 30 and 32, and guide pieces 36 may be fabricated entirely from plastic of BAKELITE material although it should be noted that other nonconductive material are also suitable.

A conventional rectangular anode structure 40 is mounted on the base 18 approximately midway between the side walls 14 and 16. Aconventional plating rack assembly 42 is supported by the uniform plating current apparatus along the side walls 14 and 16 and the front and rear retaining walls and 12. The plating rack guide pieces 36 including beveled surfaces 44 guide the plating rack into position on the front and rear retaining wall surfaces. The plating rack 42 and the uniform plating current apparatus are constructed with appropriate dimensions so that the plating rack is positioned securely between the side walls 14 and 16 and the guide blocks 36. The plating rack 42 is designed to retain the object to be plated or workpiece which may be a plurality of reed blades 46 as shown in FIG. 5. I

The various plating apparatus shown in FIGS. 2, 3 and 4 demonstrate the various current paths found in plating tanks. The apparatus of FIG. 4 shows the concept of the present invention to obtain a uniform current plating distribution. The apparatus of FIG. 2 includes a plating rack 50 with a plurality of reed blades 52 to be plated positioned in an electrolyte solution 54 contained by the plating tank 56. A conventional anode structure 58 is mounted near the bottom of a plating tank-56. A potential is applied between the anode surface 58 and the reed blades 52 causing an ionic transfer of plating current from the anode to the reed blades. The current distribution of plating current is shown by straight current paths 60 between the anode 58 and the reed blade 52 and also by curved paths 62 which swing out or curve from the anode surface to the reed blades causing an unequal plating distribution due to additional plating current delivered to the outer rows of the plating rack 50 thus causing excessive plating.

To eliminate these extraneous currents, boundary planes 64 and 66 as shown in FIG. 3 may be added at each boundary of the plating work piece or reed blades 52. This results in a current distribution of straight current paths 60 and a uniform plating current distribution with the extraneous current paths 62 of FIG. 2 being eliminated. While the addition of boundary walls or planes such as 64 and 66 eliminates extraneous current paths, this also causes turbulence and blocks the flow of. the plating solution or electrolyte which normally in constant agitation -to provide for consistent plating techniques.

The concept of the present invention as shown in FIG. 4 provides uniform plating current distribution while allowing circulation of the electrolyte solution without turbulence. Flow-blade surfaces 68, 70, 72 and 74 are utilized to provide a uniform current plating distribution by means of a tapered arrangement and are positioned to compensate for extraneous currents such as 76 that travel around the anode 58 and the flowblades and reach the reed blades 52. The extraneous current paths are of minimal consideration due to their increased resistance path. The overhanging arrangement of the lower flow-blades 74 partially blocking the direct path from the anode surface 58 t0 the reed blades 52 also provides compensation for the small contribution of extraneous current paths to the overall plating distribution.

The uniform plating current apparatus of the present invention as shown in FIGS. 1, 5, 6 and 7 provides an equal plating distribution along a work piece by means of maintaining a uniform plating current distribution in an electolyte solution without preventing the free flow of the electrolyte solution. A plurality of flow-blades are provided to accomplish the uniform current distribution. Front and rear retaining walls are provided along those surfaces of the plating rack to maintain a uniform current plating distribution in that dimension.

In a specific application of the present invention to plate a rack of reedblades, the total range of plating thickness resulting among the reedblade plating thickness was 80 to microinches. The use of conventional plating apparatus resulted in a range of plating thickness of 80 to microinches across the plating rack.

Whereas the preferred form of the invention has been shown and described herein, it should be realized that there may be many modifications, substitutions and alterations thereto without departing from the teachings of this invention.

Having described what is new and novel and desired to secure by letters patent, what is claimed is:

l. A uniform plating current apparatus for providing a uniform flow of plating current in an electrolyte solution between a plating rack carrying a work piece to be plated that forms a cathode and a quadrangular anode structure, comprising:

two generally parallel surfaces of nonconductive composition positioned-along two opposite sides of the anode surface and extending upwardly from the anode to the plating rack area; and

a first and second plurality of flow-blades running transversely between said parallel surfaces and 4 along the remaining two edges of the anode structure, said first plurality of flow-blades spaced one above the other along the distance between the anode surface and the plating rack area and said second plurality of flow-blades spaced one above the other along the distance between the anode structure and the plating rack area.

2. The uniform plating current apparatus of claim 1 further characterized in that said first and second plurality of flow-blades are generally equally spaced one from the other.

3. The uniform plating current apparatus of claim 1 further characterized in that each successive flowblade in the direction from the object to be plated to the anode structure of said first and second plurality of flow-blades is of increasing length so as to extend farther toward the opposite plurality of flow-blades and the opposite anode edge.

4. The uniform plating current apparatus of claim 1 further characterized in that the leading edges of said first and second plurality of flow-blades extending into the electrolyte solution are generally arcuately shaped so as to provide a smooth flow of the electrolyte solution past the leading edge of each flow blade.

5. The uniform plating current apparatus of claim 1 further characterized in that the work piece carries a plurality of reed blades.

6. A method for providing uniform plating current flow in an electrolyte solution between an anode structure and an object to be plated which forms a cathode surface including the steps of: positioning two generally parallel surfaces of nonconductive composition along two sides of the anode structure extending upwardly from the anode to the object to be plated; and arranging a first and second plurality of flow-blades transversely between said parallel surfaces and along the remaining two edges of the anode surface, said first plurality of flow-blades spaced one above the other along the distance between the anode structure and the ob- 5 ject to be plated and said second plurality of flowblades spaced one above the other along the distance

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1519572 *Jul 13, 1923Dec 16, 1924Wmf Wuerttemberg MetallwarenElectroplating
US2675348 *Sep 16, 1950Apr 13, 1954Greenspan LawrenceApparatus for metal plating
US2751340 *Jan 5, 1953Jun 19, 1956Clevite CorpMethod of plating
US2859166 *Sep 15, 1955Nov 4, 1958Pennsalt Chemicals CorpShielding means for effecting uniform plating of lead dioxide in the formation of lead dioxide electrodes
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4280882 *Nov 14, 1979Jul 28, 1981Bunker Ramo CorporationMethod for electroplating selected areas of article and articles plated thereby
US4643816 *May 9, 1985Feb 17, 1987Burlington Industries, Inc.Plating using a non-conductive shroud and a false bottom
US4879007 *Dec 12, 1988Nov 7, 1989Process Automation Int'l Ltd.Shield for plating bath
US4964964 *Apr 3, 1989Oct 23, 1990Unisys CorporationElectroplating apparatus
US5312532 *Jan 15, 1993May 17, 1994International Business Machines CorporationMulti-compartment eletroplating system
US5401370 *Feb 19, 1991Mar 28, 1995Atotech Deutschland GmbhDevice for masking field lines in an electroplating plant
US5589051 *Dec 9, 1994Dec 31, 1996Process Automation International LimitedClamp for use with electroplating apparatus and method of using the same
US5776327 *Oct 16, 1996Jul 7, 1998Mitsubishi Semiconuctor Americe, Inc.Method and apparatus using an anode basket for electroplating a workpiece
US5788829 *Oct 16, 1996Aug 4, 1998Mitsubishi Semiconductor America, Inc.Method and apparatus for controlling plating thickness of a workpiece
US5985123 *Jul 9, 1997Nov 16, 1999Koon; Kam KwanContinuous vertical plating system and method of plating
US6217736 *Apr 23, 1998Apr 17, 2001Atotech Deutschland GmbhMethod and apparatus for electrolytically treating a board-shaped substrate comprising shielding edge regions of the substrate during electrolytic treatment
US6391168Apr 5, 2000May 21, 2002Nec CorporationPlating apparatus utilizing an auxiliary electrode
US6753251Mar 28, 2002Jun 22, 2004Semitool, Inc.Method for filling recessed micro-structures with metallization in the production of a microelectronic device
US6806186Mar 23, 2001Oct 19, 2004Semitool, Inc.Submicron metallization using electrochemical deposition
US6821407Aug 27, 2002Nov 23, 2004Novellus Systems, Inc.Anode and anode chamber for copper electroplating
US6890416Dec 11, 2002May 10, 2005Novellus Systems, Inc.Copper electroplating method and apparatus
US6919010Aug 10, 2004Jul 19, 2005Novellus Systems, Inc.Uniform electroplating of thin metal seeded wafers using rotationally asymmetric variable anode correction
US6966976Jan 7, 2003Nov 22, 2005Hutchinson Technology IncorporatedElectroplating panel with plating thickness-compensation structures
US7144805Jul 1, 2004Dec 5, 2006Semitool, Inc.Method of submicron metallization using electrochemical deposition of recesses including a first deposition at a first current density and a second deposition at an increased current density
US7244677Feb 4, 1998Jul 17, 2007Semitool. Inc.Method for filling recessed micro-structures with metallization in the production of a microelectronic device
US7622024Jan 20, 2005Nov 24, 2009Novellus Systems, Inc.High resistance ionic current source
US7682498Jul 11, 2005Mar 23, 2010Novellus Systems, Inc.Rotationally asymmetric variable electrode correction
US7799684Mar 5, 2007Sep 21, 2010Novellus Systems, Inc.Two step process for uniform across wafer deposition and void free filling on ruthenium coated wafers
US7964506Mar 6, 2008Jun 21, 2011Novellus Systems, Inc.Two step copper electroplating process with anneal for uniform across wafer deposition and void free filling on ruthenium coated wafers
US7967969Oct 13, 2009Jun 28, 2011Novellus Systems, Inc.Method of electroplating using a high resistance ionic current source
US8092666 *Mar 25, 2008Jan 10, 2012Toyoda Gosei Co., Ltd.Method for fabricating plated product
US8262871Dec 17, 2009Sep 11, 2012Novellus Systems, Inc.Plating method and apparatus with multiple internally irrigated chambers
US8308931Nov 7, 2008Nov 13, 2012Novellus Systems, Inc.Method and apparatus for electroplating
US8475636Jun 9, 2009Jul 2, 2013Novellus Systems, Inc.Method and apparatus for electroplating
US8475637Dec 17, 2008Jul 2, 2013Novellus Systems, Inc.Electroplating apparatus with vented electrolyte manifold
US8475644Oct 26, 2009Jul 2, 2013Novellus Systems, Inc.Method and apparatus for electroplating
US8513124May 21, 2010Aug 20, 2013Novellus Systems, Inc.Copper electroplating process for uniform across wafer deposition and void free filling on semi-noble metal coated wafers
US8540857Aug 9, 2012Sep 24, 2013Novellus Systems, Inc.Plating method and apparatus with multiple internally irrigated chambers
US8575028May 16, 2011Nov 5, 2013Novellus Systems, Inc.Method and apparatus for filling interconnect structures
US8623193May 18, 2011Jan 7, 2014Novellus Systems, Inc.Method of electroplating using a high resistance ionic current source
US8703615Feb 7, 2012Apr 22, 2014Novellus Systems, Inc.Copper electroplating process for uniform across wafer deposition and void free filling on ruthenium coated wafers
US8784618 *Aug 19, 2010Jul 22, 2014International Business Machines CorporationWorking electrode design for electrochemical processing of electronic components
US8795480Jun 29, 2011Aug 5, 2014Novellus Systems, Inc.Control of electrolyte hydrodynamics for efficient mass transfer during electroplating
US8926820Sep 12, 2012Jan 6, 2015International Business Machines CorporationWorking electrode design for electrochemical processing of electronic components
US9309604May 31, 2013Apr 12, 2016Novellus Systems, Inc.Method and apparatus for electroplating
US9394620Jun 18, 2014Jul 19, 2016Novellus Systems, Inc.Control of electrolyte hydrodynamics for efficient mass transfer during electroplating
US9449808May 29, 2013Sep 20, 2016Novellus Systems, Inc.Apparatus for advanced packaging applications
US9453290Aug 15, 2013Sep 27, 2016Tel Nexx, Inc.Apparatus for fluid processing a workpiece
US9464361Jun 19, 2014Oct 11, 2016Novellus Systems, Inc.Control of electrolyte hydrodynamics for efficient mass transfer during electroplating
US9523155Dec 11, 2013Dec 20, 2016Novellus Systems, Inc.Enhancement of electrolyte hydrodynamics for efficient mass transfer during electroplating
US9624592May 13, 2013Apr 18, 2017Novellus Systems, Inc.Cross flow manifold for electroplating apparatus
US9670588Apr 11, 2014Jun 6, 2017Lam Research CorporationAnisotropic high resistance ionic current source (AHRICS)
US20020022363 *Feb 4, 1998Feb 21, 2002Thomas L. RitzdorfMethod for filling recessed micro-structures with metallization in the production of a microelectronic device
US20020102837 *Mar 28, 2002Aug 1, 2002Ritzdorf Thomas L.Method for filling recessed micro-structures with metallization in the production of a microelectronic device
US20050051436 *Jul 1, 2004Mar 10, 2005Semitool, Inc.Method of submicron metallization using electrochemical deposition of recesses including a first deposition at a first current density and a second deposition at an increased current density
US20060208272 *May 23, 2006Sep 21, 2006Semitool, Inc.Method for filling recessed micro-structures with metallization in the production of a microelectronic device
US20080237052 *Mar 25, 2008Oct 2, 2008Toyoda Gosei Co., LtdMethod for fabricating plated product
US20100032304 *Oct 13, 2009Feb 11, 2010Novellus Systems, Inc.High Resistance Ionic Current Source
US20100032310 *Nov 7, 2008Feb 11, 2010Novellus Systems, Inc.Method and apparatus for electroplating
US20100044236 *Oct 26, 2009Feb 25, 2010Novellus Systems, Inc.Method and apparatus for electroplating
US20100116672 *Jun 9, 2009May 13, 2010Novellus Systems, Inc.Method and apparatus for electroplating
US20100147679 *Dec 17, 2008Jun 17, 2010Novellus Systems, Inc.Electroplating Apparatus with Vented Electrolyte Manifold
US20120043216 *Aug 19, 2010Feb 23, 2012International Business Machines CorporationWorking electrode design for electrochemical processing of electronic components
US20120305404 *Apr 11, 2012Dec 6, 2012Arthur KeiglerMethod and apparatus for fluid processing a workpiece
USRE37050Dec 30, 1998Feb 13, 2001Process Automation International LimitedClamp for use with electroplating apparatus and method of using the same
DE3937926A1 *Nov 15, 1989May 16, 1991Schering AgVorrichtung zum abblenden von feldlinien in einer galvanikanlage
DE19717510C1 *Apr 25, 1997Oct 1, 1998Atotech Deutschland GmbhVorrichtung zur Abblendung von Galvanisiergut in Durchlaufanlagen
WO1998049375A2 *Apr 23, 1998Nov 5, 1998Atotech Deutschland GmbhDevice for electrolytic treatment of plate-shaped articles and method for electronic shielding of edge areas of articles during electrolytic treatment
WO1998049375A3 *Apr 23, 1998Feb 11, 1999Atotech Deutschland GmbhDevice for electrolytic treatment of plate-shaped articles and method for electronic shielding of edge areas of articles during electrolytic treatment
Classifications
U.S. Classification205/96, 204/279, 204/DIG.700
International ClassificationC25D5/00
Cooperative ClassificationY10S204/07, C25D17/12, C25D17/008
European ClassificationC25D5/00
Legal Events
DateCodeEventDescription
Feb 28, 1989ASAssignment
Owner name: AG COMMUNICATION SYSTEMS CORPORATION, 2500 W. UTOP
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:GTE COMMUNICATION SYSTEMS CORPORATION;REEL/FRAME:005060/0501
Effective date: 19881228