US3567595A - Electrolytic plating method - Google Patents

Electrolytic plating method Download PDF

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Publication number
US3567595A
US3567595A US670152A US3567595DA US3567595A US 3567595 A US3567595 A US 3567595A US 670152 A US670152 A US 670152A US 3567595D A US3567595D A US 3567595DA US 3567595 A US3567595 A US 3567595A
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United States
Prior art keywords
electrolyte
anode
sheet
metal
strip
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Expired - Lifetime
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US670152A
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English (en)
Inventor
Charles B Yates
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Circuit Foil USA Inc
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Circuit Foil Corp
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D7/00—Electroplating characterised by the article coated
    • C25D7/06—Wires; Strips; Foils
    • C25D7/0614—Strips or foils
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/08—Electroplating with moving electrolyte e.g. jet electroplating
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/34—Pretreatment of metallic surfaces to be electroplated
    • C25D5/42—Pretreatment of metallic surfaces to be electroplated of light metals
    • C25D5/44—Aluminium
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S204/00—Chemistry: electrical and wave energy
    • Y10S204/07—Current distribution within the bath

Definitions

  • Electroplating techniques are known in which a continuously moving metallic sheet is moved in serpentine fashion into and out of an electrolyte between successive planar anodes vertically arranged in parallelism with one another. By rendering the metallic sheet cathodic, metal is electrodeposited in the sheet as it traverses the electrolyte.
  • a system of this type is illustrated and described in copending application Ser. No. 421,048, filed Dec. 24, 1964 and now abandoned.
  • the metallic deposit be of a very high degree of uniformity of thickness.
  • Two problems are encountered in conventional methods which result in variations in coating thicknesses which are inadequate.
  • electrical current which flows from the cathode to the anode in an electroplating process often leaves the desired plating surface in a non-uniform manner, which results in uneven current distribution and plating.
  • the weight of the deposited material often varies due to changes in the deposition current efficiency resulting from an ionic imbalance in the electrolyte bath. This ionic imbalance has been found to occur because of variations in degree in flow and agitation in the electrolytic bath during the deposition process.
  • the camera attendant In developing transparent positives for use in bimetal plate making, the camera attendant normally adjusts the dot size of the transparency to allow for a given degree of dot growth.
  • the printer in using such plates is forced to accept an undesirable degree of variation in dot growth which, in multicolor work, seriously diminishes the quality of the result.
  • uniformity of chrome thickness assumes a unique degree of importance not often necessary in other sorts of chrome plating.
  • the present invention provides a process and apparatus for continuously electroplating a sheet of metal foil wherein the above-mentioned disadvantages are eliminated.
  • An even deposition of the electrodeposited layer is obtained by utilizing a novel electrically insulating shield and anode barrier arrangement in the plating tank which permits the control of the flow and agitation of the electrolytic bath during deposition.
  • FIG. l illustrates a longitudinal section of an electrolytic apparatus in accordance with the present invention taken along line 1 1 in FIG. 2;
  • FIG. 2 is a plan view partially in section of a portion of the apparatus in FIG. l;
  • FIG. 3 is a fragmentary sectional perspective view of a portion of the electrolytic apparatus of FIG. l;
  • FIG. 4 is a perspective View of the anode used in the present invention.
  • FIG. 5 illustrates in schematic form part of a plating bath in the area near the edge of an anode and a cathode.
  • the novel method and apparatus of the present invention are applicable to the electroplating of any metal on a base metal where uniformity of thickness of the electrodeposit is desired, such as copper on copper, chrome on copper, copper on steel, or the like. Since such novel method and apparatus are particularly advantageous in chrome electroplating systems, however, the ensuing description will be couched in terms of the electroplating of chrome on a continuous strip of copper, though the broad essence of the invention is not to be deemed as being so restricted.
  • the electroplating apparatus illustrated in FIG. 1 comprises a tank containing an electrolyte inlet y12 and outlet 14 for entrance and withdrawal of electrolyte 16 from the tank 10.
  • a positive bus bar 18 is secured to one longitudinal edge of the tank 10 by means of an insulating strip 20.
  • Supported on the bus bar 18 and insulating strip 20 by means of copper bars 22 are a plurality of anodes 24. These anodes 24 are shown in the form of thick planar lead plates, whose physical configuration forms an important feature of the present invention, as hereinbelow described.
  • a terminal lead 2S adapted to be connected to the positive terminal of a power source (not shown), is connected to the bus bar 118.
  • a support frame 26 is mounted on the tank 10.
  • a series of upper electrically conductive idler rollers identified by the numbers 28, 30, 32, 34 and 36 are mounted on and are in electrical contact with the support frame 26, and a series of polyvinyl chloride idler rolls 38, 40, 42 and 44 are rotatably mounted on stainless steel bars 46, 48, and 52, which in turn are connected to the supporting frame 26 at their upper ends.
  • copper sheet 54 may be rendered cathodic.
  • the continuous sheet of copper S4 which is to be electroplated is shown fed from a supply spool 56 mounted on the support frame 26, over the first upper idler 36 and into the electrolytic bath 16.
  • the continuous sheet 54 is guided into and out of the electrolyte 16 in serpentine fashion by means of the remaining idler rollers 38, 40, 42 and 44 at the bottom of the tank 10 and the upper idler rollers 28, 30, ⁇ 32 and 34.
  • the plated sheet metal then is fed across idler roller 66, past a squeegee device 68 which removes any excess material, past a pair of infrared lamps 70 and 72 to dry the plated material, onto an additional idler roller 74 and finally to the take-up roll 76 which is provided with a suitable drive mechanism (not shown) which provides the necessary force to draw the sheet of copper 54 through the system.
  • FIG. 2 illustrates a section of the electroplating system as viewed from the top. This section includes an anode 24, a cathode (which is the copper sheet 54 to be plated), a bottom idler roll 38 and a bottom roll support tube 46.
  • a reverse S-shaped barrier 90 Secured to each side edge of anode 24 at 92 is one leg of a reverse S-shaped barrier 90, which is preferably constructed of a non-conductive material such as polyvinyl chloride.
  • the other leg of each barrier is secured at 94 to one edge of a back shield 96 which is preferably constructed of polyvinyl chloride or similar non-conductive material.
  • Back shield 96 is mounted by means of nonconductive brackets 98 (preferably made of polyvinyl chloride) each of which has a slot 100 which engages an edge of back shield 96.
  • brackets 98 is, in turn, secured to a support tube 46 at 99.
  • the edges 101 of copper sheet 54 are positioned within a channel 103 formed within barrier 90 but are not secured to barrier 90 so that movement of sheet ⁇ 54 will not be obstructed.
  • channels 102 which are confined by four walls (barriers 90, an anode 24 and sheet 54) but which are open in a slot of uniform width at the bottom and open at the top.
  • confined channels 102 each have a substantially constant crosssection from the bottom to the top of anodes 24. As will be seen hereafter, the establishment of these confined channels 102 forms an essential aspect of the present invention.
  • Each anode 24 is comprised of a slab of conductive material (preferably lead in a system in which chrome is plated on a copper sheet) and is provided with a pair of conductive projections 22 (which may appropriately comprise the ends of a single copper bar) which are used to mount anode 24 on bus bar ⁇ 18 so as to establish an electrical connection between the power source and the anodes.
  • a longitudinal and horizontally eX- tending slot 110 Positioned near the top of each anode 24 but slightly below projections 22 is a longitudinal and horizontally eX- tending slot 110. Reinforcing bars 112 mounted over bracket slot provide structural strength to the anode.
  • a non-conductive sheet 113 which may appropriately be made of polyethylene.
  • a sheet of metal 54 of suitable width is fed from supply roll 56 into and out of the electrolyte solution 16 over the upper idler rollers 28, 30, 32, 34 and 36 and the lower rollers 38, 40, 42 and 44, past idler rollers 66 and 74 to the take-up reel 76.
  • the motor driven take-up reel 76 drives the sheet of metal 54 at a desired speed through the electrolytic bath 16 while a positive voltage is applied to the anodes 24 and a negative voltage to the metal sheet 54 acting as a cathode.
  • the nature of the electrodeposit on the metal sheet can be readily modified by control of electrolyte circulation within confined channel 102. Since the electrolyte circulation within channel 102 is directly related to the amount of electrolyte which is caused to flow through slots 110 of anodes 24 as a result of the gassing of the electrolyte as aforesaid, the electrolyte circulation can be modified by adjustment of the position of slots 110 relative t0 the electrolyte surface. By raising anodes 24 above the level of the electrolyte solution 16, the flow of electrolyte over the anode slot 110 ⁇ may be impeded somewhat.
  • the ow rate in the plating area can be readily adjusted by adjusting the height of the anode 24.
  • the exact position of the anode 24 must be determined for each specilic application and depends on a number of variables including the distance between the cathode and anode, the materials utilized, the electrolyte solution, the rate of movement of the sheet of material to be plated and the thickness of the plating desired. If the anode is placed too high above the level of the electrolyte solution 16, there will not be a suicient flow rate and the electrolyte will become depleted in terms of its chromatc content (in systems in which chrome plating is taking place), which will result in a loss of current efficiency and produce poor electroplating.
  • the anode 24 has been shown with a slot 110 through which the electrolyte solution 16 flows, with separate projections 22 being provided above the lower edge 114 of slot 110 for mounting of the anodes.
  • This particular construction facilitates the handling and mounting of the anode 24 and eliminates the necessity for sealing of the tank at the points at which projections 22 come in contact with the supporting tank portion. While this arrangement is thus highly advantageous, the broad advantages of the present invention may still be achieved through the use of an anode without a slot by mounting such anode with its upper edge substantially level with the electrolyte surface. In such case, the upper edge of the anode performs the function of the lower edge 11-4 of slot 110. As will be apparent, this arrangement requires that special precautions be taken to seal the tank at the points at which the anodes are mounted.
  • the arrangement of the present invention is not only effective to establish uniform electrolyte circulation patterns between the anodes and adjacent moving cathodic metallic sheets (resulting in extremely uniform electrodeposits) but provides a significant secondary advantage.
  • This secondary advantage results from the use of barriers 90 and their associated back shields 96 and can best be explained by reference to IFIG. 5, which illustrates schematically current ow between a cathode and anode in an electrolyte both with no edge shield (such as barrier 90) being present.
  • the path of the current across the bath is represented by dotted lines 200 whose spacing indicates the current density across the electrolyte.
  • the conducting path may be somewhat longer, and as a result the actual current density across the electrolyte will fall olf dramatically as one moves away from the anode edge to the left into the electrolyte volume, but the net effect as far as the cathode is concerned is a considerably higher total amount of current discharged at that edge, and consequently a thicker deposit.
  • barriers y cut off all extraneous current paths immediately before the edges of the moving cathodic sheet 54, so that current flow is not permitted to loop out into the side body of electrolyte. Except for a very narrow band of no more than 1-2 cm. in width, therefore, the edges of the sheet will see no more current flow than the center of the sheet.
  • the back shields 96 will serve as a rear current barrier to prevent electrodeposition on the rear surface of sheet S4.
  • each of anodes 24 is provided with a non-conductive sheet 113 on one of its faces.
  • This non-conductive sheet has the effect of making each anode a one-sided anode so as to avoid gas evolution on both sides of the anodes. Unless this were done, the air lift effect on one side of a given anode would cancel out that on the reverse side and the advantages of the present invention would not be obtained. A similar effect could be obtained from placing two non-insulated anodes back-toback in order to create a still volume of electrolyte between them.
  • the operating conditions employed in the carrying out of the process of the present invention will vary through wide limits depending on a number of variables including but not restricted to the nature of the base metal as well as plating metal, the thickness of the base metal, the thckness, smothness and uniformity of the plating metal which is desired, the speed of movement of the base metal sheet throughout the electrolyte, and so forth. Those skilled in the art will have no diiculty adapting the proper conditions of the present invention to the production of a particular bimetallic product.
  • a matte chrome surface may be electrodeposited on a moving copper sheet approximately 60 inches wide using an electrolyte approximately as follows:
  • the circulation of the electrolyte within the tank need not exceed more than 2 or 3 gallons per minute. This fiow is sufiicient to keep the electrolyte from being depleted but does not affect the flow characteristics caused by the Pohle air lift effect described above.
  • metal sheets can be produced having a continuously electrodeposited coating the thickness of which is extremely uniform across the entire width of the sheet.
  • the present invention can reduce this thickness variation figure to 50% and even to 30% and less.
  • a process as defined in claim 1 wherein said substantially uniform upward iiow of electrolyte is created by confining the electrolyte between said strip of metal and said anode to prevent the migration of electrolyte transversely across the edges of said strip; and maintaining the relative positions of the electrolyte surface and the anode so that electrolyte is caused by the gas evolution to circulate up over a portion of the anode adjacent said electrolyte surface so as to obtain a substantially uniform circulation pattern within said confined body of electrolyte.
  • a process as defined in claim 3 wherein a plurality of substantially vertically arranged, substantially planar anodes are immersed in said electrolyte and ⁇ wherein said strip of metal is moved through said electrolyte in serpentine fashion so as to travel alternatively upwards and downwards between successively arranged anodes. 2 7. A process as defined in claim 3 wherein said confined body of electrolyte between said strip of metal and said anode has a substantially constant cross-section in a direction parallel to the direction of movement of said strip of metal.
  • a process as defined in claim 3 wherein said anode is mounted so that an exposed upper peripheral surface is positioned substantially level with the surface of the electrolyte and wherein a plurality of substantially vertically arranged, substantially planar anodes are immersed in said electrolyte; wherein said strip of metal is moved through said electrolyte in serpentine fashion so as to travel alternatively upwards and downwards between successively arranged anodes; and wherein said confined body of electrolyte between said strip of metal and said anode has a substantially constant cross-section in a direction parallel to the direction of movement of said strip of metal.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Electroplating Methods And Accessories (AREA)
US670152A 1967-09-25 1967-09-25 Electrolytic plating method Expired - Lifetime US3567595A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US67015267A 1967-09-25 1967-09-25
US75550468A 1968-08-19 1968-08-19
US00024956A US3803013A (en) 1967-09-25 1970-03-06 Electrolytic plating apparatus and method

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US3567595A true US3567595A (en) 1971-03-02

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US670152A Expired - Lifetime US3567595A (en) 1967-09-25 1967-09-25 Electrolytic plating method
US755504A Expired - Lifetime US3567596A (en) 1967-09-25 1968-08-19 Electrolytically copper plating an aluminum wire
US00024956A Expired - Lifetime US3803013A (en) 1967-09-25 1970-03-06 Electrolytic plating apparatus and method

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US755504A Expired - Lifetime US3567596A (en) 1967-09-25 1968-08-19 Electrolytically copper plating an aluminum wire
US00024956A Expired - Lifetime US3803013A (en) 1967-09-25 1970-03-06 Electrolytic plating apparatus and method

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US (3) US3567595A (enrdf_load_stackoverflow)
BE (1) BE721365A (enrdf_load_stackoverflow)
FR (1) FR1583016A (enrdf_load_stackoverflow)
GB (1) GB1251658A (enrdf_load_stackoverflow)
LU (1) LU56951A1 (enrdf_load_stackoverflow)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4390407A (en) * 1980-09-10 1983-06-28 Fuji Photo Film Co., Ltd. Electrolytic processing device for belt-shaped metal plates
US4426266A (en) 1983-02-28 1984-01-17 Kawasaki Steel Corporation Strip edge overcoating preventing device for continuous electroplating
US4652346A (en) * 1984-12-31 1987-03-24 Olin Corporation Apparatus and process for the continuous plating of wide delicate metal foil
EP0420640A1 (en) * 1989-09-29 1991-04-03 Hironari Sawa Process for electroplating and apparatus therefor
US5084153A (en) * 1988-04-25 1992-01-28 Beckswift Limited Electrical apparatus
US5833819A (en) * 1995-12-06 1998-11-10 Mitsui Mining & Smelting Co., Ltd. Copper foil for a printed circuit board, a process and an apparatus for producing the same
US20090020712A1 (en) * 2005-03-15 2009-01-22 Fujifilm Corporation Plating processing method, light transmitting conductive film and electromagnetic wave shielding film
US20090218127A1 (en) * 2005-03-15 2009-09-03 Fujifilm Corporation Plating processing method, light-transmitting conductive film and electromagnetic wave-shielding film
US9157160B2 (en) 2013-08-22 2015-10-13 Ashworth Bros., Inc. System and method for electropolishing or electroplating conveyor belts

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5594492A (en) * 1979-01-12 1980-07-17 Nippon Kokan Kk <Nkk> Fluidizing method for liquid by jet stream between parallel flat board
JPS59193866U (ja) * 1983-06-13 1984-12-22 高安　清澄 不溶性鉛電極
US4686013A (en) * 1986-03-14 1987-08-11 Gates Energy Products, Inc. Electrode for a rechargeable electrochemical cell and method and apparatus for making same
US4919769A (en) * 1989-02-07 1990-04-24 Lin Mei Mei Manufacturing process for making copper-plated aluminum wire and the product thereof
US6361673B1 (en) 2000-06-27 2002-03-26 Ga-Tek Inc. Electroforming cell
CN102140661B (zh) * 2010-01-29 2012-08-22 富葵精密组件(深圳)有限公司 电镀装置
DE102010022743A1 (de) * 2010-06-04 2011-12-08 Ziemek Cable Technology Gmbh Elektrischer Leiter zur Übertragung von Hochfrequenzsignalen und Verfahren zu seiner Herstellung

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4390407A (en) * 1980-09-10 1983-06-28 Fuji Photo Film Co., Ltd. Electrolytic processing device for belt-shaped metal plates
US4426266A (en) 1983-02-28 1984-01-17 Kawasaki Steel Corporation Strip edge overcoating preventing device for continuous electroplating
US4652346A (en) * 1984-12-31 1987-03-24 Olin Corporation Apparatus and process for the continuous plating of wide delicate metal foil
US5084153A (en) * 1988-04-25 1992-01-28 Beckswift Limited Electrical apparatus
EP0420640A1 (en) * 1989-09-29 1991-04-03 Hironari Sawa Process for electroplating and apparatus therefor
US5833819A (en) * 1995-12-06 1998-11-10 Mitsui Mining & Smelting Co., Ltd. Copper foil for a printed circuit board, a process and an apparatus for producing the same
US20090020712A1 (en) * 2005-03-15 2009-01-22 Fujifilm Corporation Plating processing method, light transmitting conductive film and electromagnetic wave shielding film
US20090218127A1 (en) * 2005-03-15 2009-09-03 Fujifilm Corporation Plating processing method, light-transmitting conductive film and electromagnetic wave-shielding film
US8177954B2 (en) * 2005-03-15 2012-05-15 Fujifilm Corporation Plating processing method, light-transmitting conductive film and electromagnetic wave-shielding film
US8253035B2 (en) * 2005-03-15 2012-08-28 Fujifilm Corporation Plating processing method, light transmitting conductive film and electromagnetic wave shielding film
US9157160B2 (en) 2013-08-22 2015-10-13 Ashworth Bros., Inc. System and method for electropolishing or electroplating conveyor belts

Also Published As

Publication number Publication date
LU56951A1 (enrdf_load_stackoverflow) 1969-01-04
US3803013A (en) 1974-04-09
GB1251658A (enrdf_load_stackoverflow) 1971-10-27
US3567596A (en) 1971-03-02
DE1796222B2 (de) 1976-09-23
FR1583016A (enrdf_load_stackoverflow) 1969-10-10
BE721365A (enrdf_load_stackoverflow) 1969-03-03
DE1796222A1 (de) 1972-04-13

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