Abstract:
A method for performing electrochemical processes using an array of dedicated cells is disclosed. Various construction details and steps of the method are developed which promote, in one embodiment, automating the method of performing the processes and cleaning the articles between electrochemical processes. In one embodiment, the array of dedicated cells includes rinsing cells which have a rinse chamber adapted to receive an article and flow rinse fluid such that the fluid impinges against the article at predetermined locations.

Description:
[0001]    This application claims benefit from U.S. Provisional Application Serial No. 60/221,771 filed on Jul. 31, 2000.  
       CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0002]    The subject matter of this application is related to the subject matter of U.S. Patent Application Number (EH-10268) filed on even date herewith by Shallow et al. entitled “Method And Apparatuses For Electrochemically Treating An Article.” 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0003]    1. Technical Field  
           [0004]    This invention relates to a method for electrochemically processing articles, such as cylindrically shaped, hollow tubing articles, and more specifically, to methods and to apparatuses used for plating processes.  
           [0005]    2. Background Information  
           [0006]    One example of hollow articles requiring plating is tubing used in the aerospace field. The tubing is used for flowing fuel, lubricating fluid, hydraulic fluid and the like, typically in high-pressure applications. The tubing is relatively small in diameter (less than one inch) and is typically joined to a mating component using braze material. The tubing frequently receives a coating to provide a smooth surface. The coating is carefully applied because the coated tubing has controlled tolerances. The smooth surface and controlled tolerances ensure that capillary forces will urge the braze material to flow into a predetermined gap between the tubing and the component.  
           [0007]    One approach for providing the coating uses a plating process having a large-scale bath and includes disposing many pieces of tubing in the bath. A large-scale plating bath may not efficiently use the plating solutions, increasing purchasing costs and increasing disposal costs of the environmentally sensitive waste. Depending on the location of the tubing in the bath, the tubing might receive a thicker than desired coating or a thinner then desired coating. In addition, a large-scale plating bath may well be located at a sit remote from the location at which the brazing processes are carried out.  
           [0008]    Another approach for providing the coating is a brush plating process. The electrolytes used for brush plating have a higher metal content than electrolytes for conventional plating baths. Brush plating processes employ a carbon anode wrapped in a conductive pad. The conductive pad is soaked in the electrolyte. This is essential to achieve higher rates of plating deposition. A current is passed through the pad and to the article as the operator rubs the pad over the surface.  
           [0009]    An advantage of the brush plating process is little waste and acceptable levels of time for work in process. However the process is labor-intensive and variations in technique from operator to operator increase the difficulty of precisely controlling the plating thickness. In addition, the operator must handle harsh chemicals during cleaning and etching and must hold and move the anode with a repetitive motion that causes fatigue and which might cause repetitive motion injuries.  
           [0010]    Accordingly, scientists and engineers working under the direction of Applicants Assignee have sought to develop a plating process and apparatus for use with such processes that provide efficient use of solutions, efficient use of rinsing water and may be installed in local work areas.  
         SUMMARY OF INVENTION  
         [0011]    This invention is predicated in part on the recognition that using concentrated solutions of the type having higher metal content for use with high-speed plating may advantageously be used in local work areas by using dedicated plating cells. It is also predicated on recognizing that dedicated cells may be provided with flow patterns that promote rinsing processes and electrochemical processes associated with plating. Is also predicated on, in one embodiment, recognizing that such dedicated cells promote automation of the plating process. In this context, electrochemical processes refer to process steps for an article, such as etching, activating and electroplating and other steps that pass a current through an electrolyte. The current is passed between a pair of electrodes where the article acts as one of the electrodes, whether as an anode or a cathode. Rinsing refers to those steps using an apparatus to prepare the surface by removing contaminants from th surface with a rinse fluid, such as by removing electrolyte from the surface with rinse water.  
           [0012]    According to the present invention, a method for electrochemically plating an article which requires at least two preparatory process steps and a plating process step includes the step of providing an array of cells which includes electrochemical cells, each electrochemical cell being dedicated to and containing during a step the necessary solutions for carrying out the step in the plating process, each electrochemical cell having a first dedicated electrode formed by an electrode attached to the cell and being of a size and having an interior for receiving a volume of fluid connected with that step which is appropriate for carrying out the process step on a single article at that cell; the step of adding to the cell a second dedicated electrode formed by the article; and, further includes the step of moving articles relative to the cells such that a single article moves in sequential fashion through the dedicated cells.  
           [0013]    In accordance with one embodiment, the method includes flowing a volume of solution for performing the process step through the electrode of at least one of the dedicated cells.  
           [0014]    In accordance with one detailed embodiment, the method includes moving an array of tubings sequentially through the dedicated cells such that a single tubing is at each cell as the process steps are being performed and wherein the duration of time at any dedicated cell is at least equal to the duration of time at that one dedicated cell requiring the longest amount of time for carrying out the process.  
           [0015]    In accordance with one detailed embodiment, the method includes indexing the tubings of an array of tubings, each to an associated cell; moving the array of tubings with respect to the cells, each into an associated dedicated cell; performing the process step at the dedicated cell; removing the array of tubings from the dedicated cells; and, reindexing the tubings with respect the cells by moving the array of tubings together, each to the next dedicated cell, and further includes removing from the array of tubings, the tubing which has completed processing and adding a tubing to the array for beginning the method.  
           [0016]    In one detailed embodiment, the method includes moving the tubing in sequential fashion through dedicated cells for performing the steps of electrochemical cleaning using an electrolytic fluid, rinsing using water, electrochemical etching using an electrolytic fluid, rinsing using water; electrochemical activating using an electrolytic fluid; electroplating using an electroplating solution, and, rinsing using water.  
           [0017]    In one particular embodiment, the electrochemical cleaning solution is a base; the etching solution is an acid; the activating solution is sulfuric acid and ammonium sulfate; and the electroplating solution is a nickel plate solution.  
           [0018]    In one detailed embodiment, the method includes using a data processing device to determine the duration of time that a tubing spends at a dedicated cell, which includes determining the amp-hours consumed, the volume of rinse fluid consumed between dedicated electrochemical cells; and determining the dedicated cell and tubing requiring the longest time and turning off the flow of fluid and current to the other cells as appropriate once the process step being performed at a dedicated cell is complete.  
           [0019]    According to the present method, the step of rinsing a tubing includes disposing the tubing in a chamber having passages directed toward the chamber and further includes a guide member extending axially in chamber, the method further including the steps of sliding the tubing over the guide member; flowing a rinse fluid longitudinally through the guide member and radially outward through the guide member such that the fluid impinges on the interior of the tubing while simultaneously flowing fluid through the passages in the wall that are directed toward the tubing disposed in the center of the chamber under significant pressure, such as a pressure which is in excess of ten pounds per square inch gauge (10 psig) and in some applications is equal to fifteen pounds per square inch gauge (15 psig).  
           [0020]    In accordance with the present invention, the step of flowing a rinse fluid includes the steps of detecting the presence of the tubing in the chamber; flowing a predetermined amount of rinse fluid to the chamber prior to flowing the rinse fluid through the pin and through the walls the chamber.  
           [0021]    A primary feature of the present invention is a method which uses dedicated electrochemical processing cells in a plating process. In on embodiment, a feature is indexing and reindexing an array of articles with respect to the dedicated cells as the processes are performed in each cell. Another feature is forming a cell such that a first electrode forms at least a portion of electrode chamber within the cell. Another feature is disposing the article being processed in the electrode chamber to form to the second electrode. Still another feature is flowing electrolytic fluid through the electrode chamber under operative conditions. Still another feature is forming dedicated rinsing cells having passages for impinging rinse fluid against the article. Still another feature is a rinsing cell having a guide member which both positions the article in the rinsing cell and flows rinse fluid to the interior of the article to rinse away electrolytic fluid.  
           [0022]    A primary advantage of the present invention is the efficiency of the process which results from using dedicated cells having small volumes of fluid for repetitively performing a plating operation that reduce waste and purchasing costs. Another advantage is the ability to use such cells in a small, local area. An advantage of the method is the convenience of having a plating apparatus in close proximity to an area which performs brazing. Another advantage is the efficiency that results from using the dedicated cells with devices that facilitate automation of the process.  
           [0023]    The foregoing features and advantages of the present invention will become more apparent in light of the following detailed description of the best mode for carrying out the invention and accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0024]    [0024]FIG. 1 is a perspective view of an apparatus for performing plating including a schematic illustration of an indexing device for moving a plurality of articles through the coating system indexing and reindexing the articles with respect to the electrochemical cells of the apparatus;  
         [0025]    [0025]FIG. 2 is a perspective view of an electrochemical cell for performing process steps involving passing current through the cell in a method of electroplating an article, such as a tubing;  
         [0026]    [0026]FIG. 3 is a cross-sectional view of the electrochemical cell of FIG. 2 taken along the lines  3 - 3  of FIG. 2 and partially broken away for clarity;  
         [0027]    [0027]FIG. 4 is a perspective view of a guide member of the electrochemical cell shown in FIG. 3;  
         [0028]    [0028]FIG. 5 is a view from above of a rinsing cell for performing a cleaning process step which includes flowing a predetermined amount of rinse fluid to the cell;  
         [0029]    [0029]FIG. 6 is a cross-sectional view of the rinsing cell of FIG. 5 taken along the line  6 - 6  of FIG. 5 which is partially broken away for clarity, the rinsing cell being shown in an operative condition during rinsing of an article, such as a tubing. 
     
    
     DETAILED DESCRIPTION  
       [0030]    [0030]FIG. 1 is a perspective view of an apparatus  10  for performing electrochemical processes, such as a plating apparatus for applying nickel plate to tubing. FIG. 1 includes a schematic illustration on an indexing device  12  for moving a plurality of articles through the plating system. The indexing device includes one or more carriers, as represented by the horizontally extending carrier  14 . Each carrier has a plurality of openings  16  which adapts the indexing device to receive a plurality of articles, such as a plurality of tubings  18 . Each tubing has an outer wall  19  and an inner wall  20 . The indexing device includes a support  22  which might engage a belt which carries the indexing device and provides for continuous movement of indexing devices through the apparatus.  
         [0031]    As shown in FIG. 1, the plating apparatus  10  includes a plurality of cells for treating the articles, such as electrochemical cells and rinsing cells. The electrochemical cells for electrochemically treating the tubing are represented by the cells  24 ,  26 ,  28 ,  32 . These cells are formed in the same manner and are each similar in design to the representative cell  32 . Cell  32  is shown in FIG. 2 and FIG. 3 and is discussed below in more detail. Each electrochemical cell  24 ,  26 ,  28 ,  32  is in flow communication with means  34  for supplying electrochemical fluid, such as electrolytic fluid. Electrolytic fluid is commonly referred to as an “electrolyte”. The means for supplying electrochemical fluid has a reservoir  36 , a pump  38 , a filter  42  for the electrolyte, and, as shown in FIG. 3, both a supply conduit  44  and a return conduit  46  for supplying the electrolyte and removing the electrolyte from the interior of the cell. In the embodiment shown, a portion of the supply conduit  44  and return conduit  46  are part of electrochemical cell and extend through the interior of th electrochemical cell.  
         [0032]    The plating apparatus  10  includes a plurality of rinsing cells, as represented by the rinsing cells  48 ,  50 ,  52 , for cleaning the electrochemical fluid from the tubing as required. The rinsing cell is shown in FIG. 5 and FIG. 6 and is discussed in more detail below. Each rinsing cell is in flow communication with means  54  for supplying a rinse fluid, such as deionized water. The means includes a reservoir  56 , a pump  58 , a supply conduit  62  and, as shown in FIG. 5, a return conduit  64  for supplying and removing rinse fluid. In the embodiment shown in FIG. 6, a portion of the supply conduit  62  and return conduit  64  are part of the rinsing cell and extend through the interior of the rinsing cell. The return conduit is in flow communication with the reservoir  56  or might be in flow communication with a sump (not shown) for collecting the fluid for later disposal.  
         [0033]    [0033]FIG. 2 is a perspective view of one of the electrochemical cells, such as plating cell  32 . The electrochemical cell has an axis A and has an outer housing  66  having a base  68 . The outer housing includes a wall  70  which extends circumferentially about the cell. The cell has a cap  72  having an opening  74  for receiving the tubing.  
         [0034]    [0034]FIG. 3 is a cross-sectional view of the cell  32  taken along the line  3 - 3  of FIG. 2. The cross-sectional view is partially broken away for clarity. The electrochemical cell has a first electrode, as represented by the carbon-platinum electrode  76 . The first electrode is commonly referred to as a carbon electrode or housing electrode. The first electrode has at least a portion, such as a wall  78 , which extends circumferentially about the cell to form an electrode chamber  80  for receiving electrolyte. The electrode chamber has a first region, such as a bottom  82  of the electrode chamber; and a second region, such as the top  84  of the electrode chamber.  
         [0035]    The electrode chamber  80  adapts the electrochemical cell to receive electrolyte and to receive a second electrode  86  of the electrochemical cell. The second electrode is the article being processed, such as the tubing  18  which has the outer wall  19  and the inner wall  20 .  
         [0036]    The second electrode  86  (or tubing  18 ) is disposed in the electrode chamber  80  under said operative condition. The second electrode is spaced radially from the first electrode leaving a gap G therebetween. The gap G extends about the perimeter of the electrochemical cell and forms and electrolyte passage  88 . The gap G is circumferentially continuous but might be interrupted in alternate embodiments. The tubing has a hydraulic diameter D, which is four times the cross-sectional area, bounded by the perimeter of the tubing and divided by the perimeter of the tubing. In the embodiment shown, the hydraulic diameter was about four (0.4) tenths of an inch or about one (1) centimeter. They gap G was about two (0.2) tenths of an inch or about one-half of one centimeter (0.5 cm). Thus, the hydraulic diameter D is about twice the gap G.  
         [0037]    The electrical circuit includes a power supply (not shown) for providing direct current to apparatus  10 . Depending on the operation being performed, the tubing may be either the anode or the cathode of the electrical circuit that causes the electrochemical reaction. If the tubing is the anode, current flows away from the tubing. If the tubing is the cathode, current flows toward the tubing. In the embodiment shown, the tubing is, the cathode.  
         [0038]    [0038]FIG. 4 is a perspective view of a guide member  90  of the electrochemical cell. As shown in FIG. 3 and FIG. 4, the guide member is disposed in the electrode chamber  80  for guiding the tubing  18  as it enters the chamber. The guide member has a seat  92  having a tapered surface  94  facing outwardly in the axial direction. A pin  96  extends axially from the seat and is disposed in the electrode chamber  80 . The pin adapts the guide member to position the tubing in the chamber as it enters and is disposed in the cell to avoid contact between the tubing and the electrode. The seat contacts the guide member at a predetermined location to ensure that the correct length of tubing has entered the chamber. A proximity sensor  98  confirms that the tubing is in its correct location.  
         [0039]    As discussed above with FIG. 3, the annular passage  88  for electrolyte is bounded outwardly by the housing electrode  76  and inwardly by the pin  96 ; and after insertion of the tubing, inwardly by the tubing  18 . The electrolyte passage has a first or supply opening, as represented by the annular supply opening  100 . The electrolyte passage has a second or exhaust opening, as represented by the annular exhaust opening  102 . The supply opening extends in flow communication with a source of electrolyte, as represented by the supply conduit  44 . The supply conduit has a diffusion region  103  upstream of the annular supply opening  100 . A swirler, as represented by the swirler  104 , is disposed between the diffusion region and the supply opening of the electrolyte passage. The diffusion region slows the flow to reduce turbulence as the flow passes through the swirler and increases the static pressure of the flow prior to entering the swirler. Disposing the swirler between the diffusion region and the supply opening further spaces the sudden expansion of the diffusion region from the electrode chamber to ensure that unacceptable turbulence is not introduced into the flow.  
         [0040]    The swirler  104  is attached to the seat  92  of the guide member  90  for centering the guide member in the electrode chamber  80 . The swirler has a plurality of canted holes  106  or openings. The holes are an angle with respect to a plane containing the axis A. The holes impart a lateral or circumferential component of velocity to the electrolyte as the electrolyte flows in a generally axial direction through the swirler and thence through the electrolyte passage adjacent the tubing. The velocity is small enough to avoid cavitation and large enough to avoid other discontinuities in electrolyte concentration which might form because of the passage of the electrical current through the electrolyte. In the embodiment shown, the swirler is disposed between the electrode and adjacent structure of the electrochemical cell. In an alternate-embodiment, for example, the swirler might be disposed entirely within the electrode chamber or disposed upstream of the electrode to such an extent that it is spaced axially from the electrode.  
         [0041]    The return conduit  46  includes a collection chamber  108 . The collection chamber is an annular chamber bounded by the wall  70  of the outer housing  66 . The wall  70  extends circumferentially about and is radially spaced from the housing electrode  76 . The collection chamber receives electrolyte exhausted from the electrolyte passage through the exhaust opening  102 .  
         [0042]    The cap  72  has return holes  110 . These holes provide a passage for returning electrolyte to the cell  32  as the tubing is removed from the cell and drops of electrolyte fall from the tubing. The cap includes a plat  112  which is spaced axially from the housing electrode  76  leaving an overflow passage  114  therebetween. The overflow passage places the annular electrolyte passage  88  in flow communication with the collection chamber  108 .  
         [0043]    The opening  74  also constrains the tubing against radial movement as the tubing is moved axially into the electrochemical cell. Thus, the opening aligns the tubing with the pin  96  and also blocks the tubing from contacting the housing electrode  76 . In alternate embodiments, the opening might have a conical shape so that the opening tapers in the axial inward direction to accommodate a degree of misalignment between the opening and the tube. In the present embodiment, either the opening  74  or the guide member  90  provides means for guiding the tubing, as the tubing is disposed in electrochemical cell. Thus, both the guide member  90  and the opening  74  in the cap cooperate to locate and constrain movement of the tubing  18  as it enters the electrochemical cell to block contact between the tubing and the cell which might otherwise cause a short-circuit.  
         [0044]    As mentioned about the embodiment shown, the pin  96  is a sufficient length such that the opening  74  centers the tubing  18  on the guide member  90 . Accordingly, the opening is not needed to constrain errant movement of the tubing which is already constrained by the guide member. In an alternate embodiment, the guide member might be eliminated by having an opening of sufficient axial length that the tubing is centered in the electrode chamber and engages a stop which corresponds to tapered surface  94  of the guide member.  
         [0045]    During operation of the electrochemical cell  32 , electrolyte is supplied to the bottom of the cell through the supply conduit  44 . The electrolyte flows upwardly into the electrode chamber  80  with a slight circumferential velocity. This circumferential velocity does not create turbulence but does block the formation of regions of varying electrolyte concentration which might be induced by the flow of current through the electrolyte.  
         [0046]    Flowing the electrolyte fluid vertically to the overflow passage enables a reasonably uniform removal of fluid from the circumference of the electrolyte passage. Flowing electrolyte fluid vertically and in a downward direction and removing the fluid through a single drain hole might introduce variations in concentration of the electrolyte which might adversely affect plating activity. In addition, the guide member is centrally disposed in the electrode chamber inside the article to be coated. As a result, the guide member does not interfere with the passage of current from the cathode to the anode by introducing a nonconductive material into the electrical field.  
         [0047]    An advantage of the electrochemical cell is that small solution volumes are usable for processing a single tubing. This decreases environmental impact as compared to large plating tanks, producing smaller amounts of waste compared to large batch processing. The small size enables the cells to be located in a local area with acceptable lead-time and just in time production for producing parts. In addition, the quality of the plating system enabled maintaining tolerances that were smaller than a thousandth of an inch.  
         [0048]    [0048]FIG. 5 is a view from above of the rinsing cell  52  with a tubing  18  installed in the rinsing cell. The rinsing cell is disposed about an axis of symmetry R. FIG. 6 is a cross-sectional view of the rinsing cell  52  taken along the line  6 - 6  of FIG. 5 with a portion of the rinsing cell partially in full and partially broken away for clarity. The rinsing cell has a wall  122  which extends circumferentially about the axis R to form a rinse chamber  124 . The rinse chamber is bounded by an axially facing surface  126  and has a lower region or bottom  128 . The supply conduit  62  includes a supply passage  130  for rinse fluid which is disposed in the cell and is in flow communication with the means  54  for supplying rinse fluid to the cell.  
         [0049]    A guide member  132  is disposed in the rinse chamber  124  and extends axially in the chamber. In the embodiment shown, the guide member extends in the vertical direction. The guide member has a base  134  and a pin  136 . An axially extending passage  138  for rinse fluid extends through the base and the pin. The guide member has a plurality of impingement holes  140 . The impingement holes place the passage  138  of the pin in flow communication with the interior of the rinse chamber. In the operative condition, the tubing  18  is disposed about the guide member  132  and is spaced from the pin leaving an annular drain passage  142  therebetween. The tubing is disposed about the guide member such that impingement flow strikes the inside or inner wall  20  of the tubing. The impingement holes may be angled toward the bottom  128  of the rinse chamber to impart an axial component of velocity to the flow. The axial component of velocity decreases the effect that splash back from the impingement stream has on the flow. The vertical orientation of the drain passage causes gravity to urge the rinse fluid to flow downwardly along the inside of the tubing.  
         [0050]    The base  134  of the guide member has a plurality of slots  144 . The slots are spaced axially from the bottom of the rinse chamber. The slots are spaced circumferentially about the base leaving a seating surface  146  therebetween. The seating surface diverges axially to a diameter which is larger than the diameter of the inner wall of the tubing to locate the tubing in the axial (vertical) direction. The seating surface adapts the base member to engage the tubing at a line of contact. The line of contact is interrupted by the slots to permit drainage of the rinse fluid to the bottom of the chamber.  
         [0051]    The rinsing cell has a cap  148 . The cap has a hole  150  which adapts the cell to receive the tubing  18 . The supply conduit  62  for rinse fluid includes other passages on the interior of the rinsing cell. For example, the cap has a plurality of radially directed impingement passages  152  in flow communication with the rinse chamber  124 . The passages are directed toward the bottom of the rinse chamber to impart an axial component of velocity to the rinse flow. As with the interior of the tubing, the axial component of velocity decreases the effect that splash-back of rinse fluid impinging on the tubing has on flow to the bottom of the chamber. The cell includes a circumferentially extending plenum  154  which is in flow communication with the radially directed impingement passages and is, in turn, in flow communication through axial passages  156  and  144  with the supply passage  130  in the cell. The means  54  for supplying rinse fluid includes the supply conduit  62  and the return conduit  64  which are each in flow communication with the rinse fluid reservoir  56 . As shown, the return conduit is spaced from the bottom of the rinse chamber. Alternatively, the return conduit may be in flow communication with the bottommost portion of the rinse chamber to completely drain rinse fluid from the rinse chamber.  
         [0052]    An advantage of the rinsing cell is the controlled dispensing of rinse fluid, such as water, under pressure which produces a small amount of waste and the lower costs associated with waste disposal. In addition, automating the rinsing process minimizes operator fatigue and eliminates continuous movements by the operator of a rinsing device which might lead to repetitive motion injuries were one person to rinse a large volume of tubes moving through the assembly line on a daily basis.  
         [0053]    During operation of the apparatus  10 , the apparatus may be used by hand by eliminating the tubing carrier  14  or may use the tubing carrier with hand operation automatically with sensors. For example, the electrochemical cell and the rinsing cell might each have a proximity sensor, such as the inductive sensors  98 ,  158  which sense the presence of the tubing in the correct position in the cell. The sensor might rely on conductivity or inductivity of the tubing to trigger the sensor. In one embodiment, an inductive sensor was used which fits into the side of the housing. The inductive sensor triggers a relay timer. For the rinse system, the relay timer used is specifically set to a single shot mode for supplying the rinse fluid. Upon receiving a signal from the sensor, the timer closes a function circuit to provide a given duration of flow. Removing the tubing resets the system such that the timer can again be reactivated to provide rinse flow. The function circuit could be any conventional circuit such as, for example, one that is solenoid operated with a close center fluid control valve. The valve will allow flow of water to the rinse system when the tube is present and sensed by the inductive sensor.  
         [0054]    During operation of the plating system  10 , the first electrochemical cell  24  provides electrochemical cleaning to the tubing by flowing current toward the tubing, that is, the housing electrode is the anode and the tubing is the cathode. In one example involving the use of steel tubing and nickel plate on the tubing, the electroplating fluid was a sodium hydroxide base of about one (1) to five (5) percent sodium hydroxide by weight with the remainder as water. One satisfactory electrolyte is available from Sifco Industries, Cleveland, Ohio as Sifco Selectron Solution Code SCM 4100 electrolyte solution. Following a rinse cycle with water in the rinsing cell  48 , the tubing is disposed in the second electrochemical cell  26  for etching. One satisfactory electrolyte is Sifco Selectron Solution Code SCM  4250 , Activator No. 4 solution which is about five (5) to ten (10) percent by weight hydrochloric acid (HCl) with the balance water. Etching is provided by flowing current away from the tubing, that is, the housing electrode  76  of cell  26  becomes the cathode and the tubing becomes the anode. Following a second rinse cycle in rinsing cell  50 , the tubing is disposed in the third electrochemical cell  28  for activating the surface of the tubing for plating. Activating is provided by flowing current toward the tubing, that is, the housing electrode becomes the anode and the tubing becomes the cathode. One satisfactory electrolyte is Sifco Selectron Solution Code SCM 4200, Activator No. 1 which is about five (5) to ten (10) percent sulfuric acid by weight; about seven (7) to thirteen (13) percent ammonium sulfate by weight with the remainder water. Finally, the tubing is removed from the activating electrochemical cell and moved directly to the plating cell  32  without rinsing. One satisfactory plating electrolyte is Sifco Selectron Solution Nickel Code SPS 5600. It is important that the activating solution not dry on the tubing before entering the plating cell.  
         [0055]    During operation of the plating system  10 , the method may be used automatically to treat a plurality of tubings  18  with electrochemical processes. The steps include forming an array of dedicated cells, that is, dedicated to performing a single process. The array of dedicated cells might be an array of electrochemical cells  24 ,  26 ,  28 ,  32  or an array of electrochemical cells  24 ,  26 ,  28 ,  32  and an array of rinsing cells  48 ,  50 ,  52  as shown. The array of cells is disposed with the cells in proximity one to the other such that their proximity enables relative movement of each tubing from one cell to the next, whether the next cell is an electrochemical cell or a rinsing cell.  
         [0056]    In the embodiment shown, the tubings  18  are indexed to the dedicated cells  24 ,  48 ,  26 ,  50 ,  28 ,  32 ,  52  such that each tubing is aligned with the dedicated cell which is associated with the next process to be performed on the tubing. After the process is performed on the tubing, the array of tubings is reindexed such that each tubing moves to the next cell. A new tubing is added to the array and the finished tubing at the last cell is removed. As mentioned earlier, the electrolyte is flowed at a relatively steady rate in electrochemical cells and through the electrolyte passage  88  and from the cell. In rinsing cells, a predetermined amount of rinse fluid is supplied to the cell for each tubing that is processed. In one application, the amount of rinse fluid for each tubing was less than one ounce of fluid. The fluid is flowed from either type of cell during the process. In the rinsing cell, a small amount of rinse fluid may remain below the tubing in the bottom of the cell.  
         [0057]    A data processing device  162 , such as a computer, may be used with the array of cells  24 ,  48 ,  26 ,  50 ,  28 ,  32 ,  52  by being in signal communication with the cells through electrical conduits  164 . This provides a data processing capability to the plating system  10 . The data processing device may be programmed to calculate the duration of time that each tubing spends at each dedicated cell which necessarily determines the longest duration of time at each cell. The device causes each tubing to remain at its dedicated cell until the tubing requiring the longest processing time has completed its process. The data processing device turns off the process at the other cells as each process reaches its conclusion. Thus, the process may be automated with associated reductions in cost and materials.  
         [0058]    Although the invention has been shown and described with respect to detailed embodiments thereof, it should be understood by those of ordinary skill that various changes in form and in detail thereof may be made without departing from the spirit and scope of the claimed invention.