Patent Abstract:
A conveyorized electroplating device having an anode positioned proximate to a plurality of absorptive applicator assemblies that apply a plating solution to a substrate and a conveyor device that grips the substrate thereby isolating the electrical contact from the plating solution. The conveyorized electroplating device has a fluid bed assembly with a manifold and an anode, a conveyor device adjacent to the fluid bed assembly, and a plurality of absorptive applicator assemblies, wherein the plurality of absorptive applicator assemblies are adjacent and in close proximity to the anode and in fluid communication with the fluid bed assembly. The conveyor device isolates the electrical contacts from the plating solution and is able to handle various sizes and thicknesses of substrates.

Full Description:
This is a divisional application of U.S. Pat. application Ser. No. 09/422,612 filed on Oct. 21, 1999 now U.S. Pat. No. 6,294,060. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to apparatus and methods for conveying and electroplating a substrate. More particularly, the present invention is generally directed to a conveyorized electroplating device having an anode positioned proximate to a plurality of absorptive applicator assemblies that apply a plating solution to the substrate and a conveyor device that grips the substrate thereby isolating the electrical contact from the plating solution. 
     2. Description of the Invention Background 
     Many conventional electroplating devices typically employ mechanisms for moving substrates through a series of large baths or large tanks containing a plating solution. One of the disadvantages of this type of electroplating device is the lengthy amount of time to complete the electroplating process. For example, electroplating one (1) mil of copper in holes contained within a substrate may take in excess of one (1) hour. Another disadvantage of this type of conventional electroplating device is the relatively low exchange of metallic ions at the substrate surface due to the limitations of the bath circulation and the off contact nature of the anode/cathode positions. 
     Some conventional horizontal electroplating conveyor systems that deliver electrical power to the substrate include a driven roller type conveyor system and a non-driven roller type conveyer system. The driven roller type conveyor system includes solid or disk type rollers to convey the substrate through the plating area The non-driven roller system grips the substrate at its edges by spring loaded contacts and pulls the substrate through the plating area. Both of these systems suffer from the problem of exposing electrified metallic surfaces to plating solution which necessitates the removal of the resulting undesired plating from the roller assemblies thus, preventing them from acting as reliable and dimensionally stable electrical contacts so that current can be delivered to the substrate. 
     Thus, the need exists for a conveyorized electroplating device that can electroplate a substrate in a relatively short time while providing a high exchange of metallic ions at the substrate surface resulting in a substrate that has a uniform electroplated surface. 
     The need also exists for a conveyorized electroplating device that minimizes the need to recondition the electrical contacts that are exposed to plating solution thus, assuring a more reliable and repeatable contact point and a more stable process. 
     Yet another need exists for a conveyorized electroplating device that has the ability to handle substrates of various sizes and thickness without the need for mechanical adjustment. 
     SUMMARY OF THE PRESENT INVENTION 
     One form of the present invention provides a conveyorized electroplating device that electroplates a substrate in a relatively short time and exhibits a relatively high exchange of metallic ions at the substrate resulting in a uniform electroplated surface. 
     The present invention may also include a conveyorized electroplating device comprising a fluid bed assembly having a manifold and an anode, a conveyor device adjacent to the fluid bed assembly, and a plurality of absorptive applicator assemblies wherein the plurality of absorptive applicator assemblies are adjacent and in close proximity to the anode and in fluid communication with the fluid bed assembly. 
     The present invention may also include a fluid bed assembly having a plurality of baffles received within the manifold such that the plating solution will flow uniformly from the fluid bed assembly. 
     The present invention may comprise a conveyorized electroplating device that includes a plurality of absorptive applicator assemblies, a conveyor device and an anode, wherein each of the plurality of absorptive applicator assemblies has a profile and defines a fluid passageway that delivers plating solution thereto, and wherein the anode has a profile that corresponds to the profiles of the absorptive applicator assemblies. 
     Another embodiment of the present invention provides for a conveyor device that isolates the electrical contacts from the plating solution and that is able to handle various sizes and thicknesses of substrates. The conveyor device of the present invention may include a drive assembly and a gripper assembly connected thereto, wherein the gripper assembly has a non-metallic housing, a metallic member slideably mounted within a cavity defined by the non-metallic housing, an arm pivotably mounted to the housing and forming a passageway, and a seal mounted adjacent to the arm. 
     The present invention further provides for a modular conveyorized electroplating device, wherein multiple modular conveyorized electroplating devices are used together depending on the specific needs of the application. Furthermore, the modular conveyorized electroplating device makes it easy for the user to maintain and replace one or more of the modular conveyorized electroplating devices. 
     The present invention may also comprise a method of conveying and electroplating a substrate, comprising gripping the substrate at the edges thereof, electrifying the substrate, moving the substrate on or between a plurality of absorptive applicator assemblies, pumping a plating solution in contact with the absorptive applicator assemblies and onto the substrate, and isolating the electrical contact at the substrate from the plating solution. 
     Other details, objects and advantages of the present invention will become more apparent with the following description of the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For the present invention to be readily understood and practiced, various embodiments will be described in conjunction with the following figures wherein: 
     FIG. 1 is a perspective view of the conveyorized electroplating device of the present invention wherein several modules are placed end to end to create the desire length of the electroplating process; 
     FIG. 2 is a perspective view of one of the modules of the conveyorized electroplating device of the present invention, wherein a portion of the housing has been removed; 
     FIG. 3 is a perspective view of one of the modules of the conveyorized electroplating device of the present invention, wherein the entire housing has been removed; 
     FIG. 4 is an exploded view of a fluid bed assembly of the conveyorized electroplating device of the present invention shown in FIG. 3; 
     FIG. 5 is a cross-sectional view of a fluid bed assembly of the present invention shown in FIG.  4  and taken along line  5 — 5 ; 
     FIG. 6 is a perspective view of a drive assembly of the conveyorized electroplating device of the present invention shown in FIG. 3; 
     FIG. 7 is a perspective view of a gripper assembly of the conveyorized electroplating device of the present invention shown in FIG. 3; 
     FIG. 8 is a front view of the gripper assembly shown in FIG. 7; 
     FIG. 9 is a top view of the gripper assembly shown in FIG. 7; 
     FIG. 10A is a sectional view of the gripper assembly shown in FIG.  8  and taken along line  10 — 10 , wherein the extension is in the unengaged position and no substrate is being gripped; 
     FIG. 10B is another sectional view of the gripper assembly, wherein the extension is in the intermediate position and a substrate is being gripped; 
     FIG. 10C is another sectional view of the gripper assembly, wherein the extension is in the fully engaged position and a substrate is being gripped; 
     FIG. 10D is another sectional view of the gripper assembly, wherein the extension is in the intermediate position and no substrate is being gripped; 
     FIG. 11 is a perspective view of an upper roller assembly of the conveyorized electroplating device of the present invention shown in FIG. 3; 
     FIG. 12 is a right side view of the upper roller assembly shown in FIG. 11; 
     FIG. 13 is a longitudinal sectional view of the upper roller assembly shown in FIG.  12  and taken along line  13 — 13 ; 
     FIG. 14 is a perspective view of the lower roller assembly of the conveyorized electroplating device shown in FIG. 3; 
     FIG. 15 is a right side view of the lower roller assembly shown in FIG. 14; 
     FIG. 16 is a longitudinal sectional view of the lower roller assembly shown in FIG.  15  and taken along line  16 — 16 ; 
     FIG. 17 is a diagrammatical top view of the drive assembly and gripper assemblies of the conveyorized electroplating device of the present invention shown in FIG. 3; 
     FIG. 18 is a diagrammatical multiple layer sectional view of the conveyorized electroplating device of the present invention shown in FIG. 3; 
     FIG. 19A is a diagrammatical sectional view of the drive assembly and gripper assemblies of the present invention shown in FIG.  17  and taken along line  19 — 19 ; 
     FIG. 19B is a diagrammatical sectional view of another embodiment of the drive assembly and gripper assembly of the present invention having a cleaning device; 
     FIG. 20 is a sectional view of the gripper assemblies illustrating the movement of the gripper assemblies during the process of plating the substrate and also illustrating an alternative embodiment of the first contact; 
     FIG. 21 is an exploded perspective view of another embodiment of the conveyorized electroplating device of the present invention; 
     FIG. 22 is another exploded perspective view of the conveyorized electroplating device of the present invention shown in FIG. 21, wherein the absorptive applicator assemblies have been removed; 
     FIG. 23 is an exploded view of the fluid bed assembly of the conveyorized electroplating device of the present invention shown in FIG. 21; 
     FIG. 24 is a sectional view of another embodiment of the coveyorized electroplating device of the present invention having absorptive applicator assemblies; 
     FIG. 25 is a perspective view of yet another embodiment of the conveyorized electroplating device of the present invention; 
     FIG. 26 is a sectional view of the conveyorized electroplating device shown in FIG. 25; 
     FIG. 27 is a top view of the conveyorized electroplating device shown in FIG. 25; 
     FIG. 28 is a perspective view of another embodiment of the conveyorized electroplating device of the present invention; 
     FIG. 29 is a sectional view of the conveyorized electroplating device of the present invention shown in FIG. 28; 
     FIG. 30 is a top view of the conveyorized electroplating device of the present invention shown in FIG. 28; 
     FIG. 31 is a perspective view of yet another embodiment of the conveyorized electroplating device of the present invention; 
     FIG. 32 is a sectional view of the conveyorized electroplating device of the present invention shown in FIG. 31; 
     FIG. 33 is a top view of the conveyorized electroplating device of the present invention shown in FIG. 31; 
     FIG. 34 is a perspective view of yet another embodiment of the conveyorized electroplating device of the present invention; 
     FIG. 35 is a sectional view of the conveyorized electroplating device of the present invention shown in FIG. 34; 
     FIG. 36 is a top view of the conveyorized electroplating device of the present invention shown in FIG. 34; 
     FIG. 37 is an enlarged view of the conveyorized electroplating device of the present invention shown in FIG. 34 illustrating the anode and the absorptive applicator assemblies; 
     FIG. 38 is a side view of one of the absorptive applicator assemblies of the conveyorized electroplating device of the present invention shown in FIG. 34; 
     FIG. 39 is a sectional view of the absorptive applicator assembly shown in FIG. 38; 
     FIG. 40 is side view of another embodiment of the absorptive applicator assemblies of the conveyorized electroplating device of the present invention; 
     FIG. 41 is a sectional view of the shaft of the absorptive applicator assembly shown in FIG. 40; 
     FIG. 42 is a side view of yet another embodiment of one of the absorptive applicator assemblies of the conveyorized electroplating device of the present invention; and 
     FIG. 43 is an enlarged sectional view of the absorptive applicator assembly shown in FIG.  42 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention will be described below in terms of apparatuses and methods for electroplating and conveying a circuit board. It should be noted that describing the present invention in terms of electroplating and conveying a circuit board is for illustrative purposes and the advantages of the present invention may be realized using other structures and technologies that have a need for an apparatus and a method for electroplating and/or conveying a substrate. 
     It is to be further understood that the Figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for purposes of clarity, other elements and/or descriptions thereof found in a typical conveyorized electroplating device. Those of ordinary skill in the art will recognize that other elements may be desirable in order to implement the present invention. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements is not provided herein. 
     FIG. 1 is a perspective view of the modular conveyorized electroplating device  100  of the present invention, wherein several modules  102  can be placed end to end to create the desire length of the electroplating process. Although the illustrated modular conveyorized electroplating device system  100  of FIG. 1 comprises three modules, any number of modules  102  can be placed end to end. The modular conveyorized electroplating device system  100  has an input station  104  and an output station  106  such that a circuit board substrate (not shown) is loaded into the modular conveyorized electroplating device system  100  at the input station  104  and exits at the output station  106  after being electroplated. The housing  108  of the modular conveyorized electroplating device system  100  may have several removable panels such that the internal mechanisms of the modular conveyorized electroplating device  110  can be easily accessed for maintenance. 
     FIG. 2 is a perspective view of one of the modules  102  of the modular conveyorized electroplating device system  100  of the present invention, wherein part of the housing  108  has been removed for clarity. The module may include an input section  103  and an output section  105  if used alone. The modular configuration of the conveyorized electroplating device system  100  allows for the fluid bed assembly  112 , the conveyor device  114  and the absorptive applicator assemblies  116  to be easily removed from the module  102  for maintenance and replacement thereof. Each of the modules  102  of the conveyorized electroplating device system  100  comprises one or more fluid bed assemblies  112 , a conveyor device  114  and absorptive applicator assemblies  116 , each of which are discussed in greater detail below. 
     FIG. 3 is a perspective view of a single conveyorized electroplating device  110  of the present invention, wherein the housing  108  has been completely removed for clarity. The fluid bed assembly  112  extends across and above some of the absorptive applicator assemblies  116 . One of the longitudinal edges of the fluid bed assembly  112  is parallel and adjacent to the longitudinal axis of the conveyor device  114 . The absorptive applicator assemblies  116  comprise upper roller assemblies  118  and corresponding lower roller assemblies  120 . The lower roller assemblies  120  define a track  119  for the circuit board substrate to travel thereon. The upper and lower roller assemblies  118  and  120  are rotatably supported at their ends by bearing blocks  121 . The longitudinal edge of the conveyor device  114  is adjacent and parallel to the longitudinal edge of the absorptive applicators assemblies  116 . The conveyor device  114  also includes a drive assembly  150  and a gripper assembly  124 . 
     FIGS. 4 and 5 illustrate a fluid bed assembly  112  of the conveyorized electroplating device  110  shown in FIG.  3 . The fluid bed assembly  112  comprises a manifold  130 , a plurality of baffles  132  and an anode  134 . In this embodiment, the manifold  130  is substantially rectangular and defines several receptacle portions  135  each having an inlet  136  and a plurality of stand offs that take the form of rod members  138 . The inlets  136  are in fluid communication with a plating solution reservoir  111 , as shown in FIG.  3 . The plating solution is pumped to the inlets  136  through conduit  101  by pump  109 , as shown in FIG.  3 . Each of the rod members  138  define a recess (not numbered) for supporting the plurality of baffles  132 . The shelf  144  extends inwardly from the vertical walls of the manifold  130  and around the periphery of each of the receptacle portions  135 . The shelf  144  acts to redirect the plating solution so that the plating solution exits the anode holes  148  uniformly. Other types of mechanisms that may be used to redirect the plating solution are diffuser cones. The manifold  130  further has a plurality of mounting claws  140  defining holes (not numbered) for mounting the manifold  130  securely onto the housing  108  using any conventional fasteners such as screws. The manifold  130  also has a seal  142  around its periphery at  141  where it is connected to holes  359  located around the periphery of the anode  134  with suitable fasteners such as stainless steel, titanium or plastic screws or a clamping system. The manifold  130  may be made of polyvinylchloride as well as a variety of other materials which will be apparent to one of ordinary skill in the art. The seal  142  may be a hard rubber gasket, a silicone sealer or any other material that is compatible with the fluid bed assembly  112 . 
     The baffles  132  are substantially rectangular members having several pins  145  extending from the top surface of the baffles  132  and defining a second recess (not numbered) for receiving fasteners  143  extending through holes  361  located within the periphery of the anode  134  thus, attaching the anode  134  to the baffles  132 . Thus, the baffles  132  are received within the manifold receptacles  135  and are supported by the rod members  138  and are connected to the rod members  138  by fasteners  146  such as stainless steel screws. The baffles  132  may be made from polyvinylchloride as well as a variety of other materials, which will be apparent to one of ordinary skill in the art. Although not illustrated, the shape of the baffles  132  may take a variety of configurations that will be apparent to one of ordinary skill in the art. Also the conveyorized electroplating device of the present invention may be made without baffles  132 , as will be described below. 
     The anode  134  is a planar member having a substantially rectangular shape and a defining plurality of holes  359  and  361  extending through the anode  134 . As stated above, fasteners  143  such as stainless steel screws extend through the holes  361  and connect to the pins  145 . See FIG.  5 . The anode  134  is further supported by the manifold  130  in that the anode  134  rests on the manifold&#39;s periphery at  141  and is attached by stainless steel screws being received in holes  359 . The anode  134  further comprises slots  148  through which the plating solution passes. The fluid bed assembly  112  attaches to the housing  108  at its mounting claws  140 . The fluid bed assembly  112  is positioned such that the anode  134  is in sufficiently close proximity to the absorptive applicator assemblies  116  (FIG. 3) in order to provide a relatively high metallic ion exchange between the anode  134  and the substrate  217 . The anode  134  may be titanium, copper, tin, a precious metal, or an inert metal depending on the application. 
     FIG. 6 is a perspective view of a drive assembly  150  of the conveyorized electroplating device  110  shown in FIG. 3, which illustrates part of the conveyor device  114  of the present invention. The drive assembly  150  comprises an actuator in the form of a chain  152  with mounting attachments  154  connected thereto, a drive frame  156 , a drive mechanism  158 , a driven mechanism  160 , a chain tension block  162 , chain guides  164  and an actuator drive  126 . The chain  152  moves along the length of the drive frame  156  and around the drive mechanism  158  and driven mechanism  160 . Mounting attachments  154  attached to the chain  152  are substantially planar members that are rigid and have a somewhat square shape with rounded edges. The drive frame  156  is fixedly attached to the housing  108  by any conventional fastening method. The drive mechanism  158  and the driven mechanism  160  are rotatable. The driven mechanism  160  is rotated by the actuator drive  126  which results in the movement of the chain  152 . The chain tension block  162  allows for the tightening or loosening of the chain  152  (i.e., decreasing or increasing the slack in the chain). The chain guides  164  provide that the chain  152  move in a substantially straight path along the length of the drive frame  156 . The actuator drive  126  comprises a drive motor  122  and gear box. The drive assembly may alternatively comprise pneumatics, electrical and hydraulic components. 
     FIGS. 7-10 illustrate one of the gripper assemblies  124  of the conveyorized electroplating device  110  of the present invention shown in FIG.  3 . The gripper assembly  124  comprises a non-metallic housing  166 , a metallic member  168 , a pivotable panel support  172  which takes the form of an arm, and a seal  176 . The non-metallic housing  166  comprises a T-shaped member  178  and a second member  180  (FIGS.  7  and  8 ). The T-shaped member  178  has a trunk  182  and two branches  184  extending substantially perpendicular from the trunk  182 . The trunk  182  is a substantially elongated rectangular member and has a cavity  186  therein (FIG.  10 A). The cavity  186  slidably receives the metallic member  168 . The second member  180  of the housing  180  also defines a passage  170  which receives the trunk  182  of the T-shaped member  178 . The second member  180  further defines a mounting portion  190  having a plurality of holes  192 , shown in hidden lines in FIGS. 10A-10D. The mounting portion  190  is connected to the mounting attachments  154  by stainless steel screws or other appropriate fasteners. A housing biasing member  194  extends between each branch  184  of the T-shaped member  178  and the second member  180  of the housing  166  (FIG. 8) and are received within cavities  185  (shown in hidden lines) of the second member  180  of the housing  166 . The housing  166  may be made of a variety of non-metallic materials such as polypropylene or polyethylene as well as any other non-metallic materials that are compatible with plating solution and the operating temperature of the electroplating device of the present invention that will be apparent to one of ordinary skill in the art. The housing biasing members  194  may be coil springs; however, other biasing members can also be used as will be apparent to one of ordinary skill in the art. 
     Referring to FIGS. 10A through 10D, the metallic member  168  comprises a first contact  197 , a second contact  199 , a first biasing member  200 , a second biasing member  202 , flexible contact wire  204  and a roller  206 . The contact wire  204  may also take the form of a braided or multi-stranded wire. The first contact  197  is a substantially elongated rectangular member having the roller  206  rotatably connected thereto by a set screw  208  such that the set screw  208  transverses the longitudinal axis of the first contact  197 . The first contact  197  also defines an opening  198 . The second contact  199  is a substantially elongated rectangular member, defining an opening  210  therein, and having an extension  212  extending therefrom and through an opening  214  in the T-shaped member. The first biasing member  200  is between the first and second contacts  197  and  199 . The contact wire  204  is connected to and extends between the first contact  197  and the second contact  199 . The contact wire  204  is attached to the first and second contacts  197  and  199  by set screws  218 . The second biasing member  202  is positioned at the base of the cavity  186 . The first and second biasing members  200  and  202  may be coil springs; however, a variety of other biasing members can be used which will be apparent to one of ordinary skill in the art. The first and second biasing members  200  and  202  have a greater stiffness than the stiffness of the housing biasing members  194 . The first and second contacts  197  and  199 , the first and second biasing members  200  and  202 , contact wire  204  and the roller  206 , may be made form a variety of metallic materials such that electrical current will be easily conducted therethrough. 
     The pivotable panel support  172  is a substantially L-shaped arm member having one leg thereof pivotally connected to the housing  166  by a pin  213  and the other leg of the L-shaped member free to swing in an arc and thus form a passageway  174  with the housing  166 . 
     The seal  176  is attached to the exterior of the trunk  182  and adjacent the pivotable panel support  172  by any conventional fasteners such as adhesive, pins, or clips. The seal  176  is a conical compressive seal fabricated from, for example, EDPM such that after the seal  176  is compressed (FIGS:  10 B,  10 C and  10 D), the seal  176  will spring back to its original form (FIG.  10 A). The length of the free leg of the pivotable panel support  172  is sized such that when the pivotable panel support  172  is pivoted about pin  213  toward the seal  176 , the seal  176  forms a fluid tight seal therewith (FIG.  10 D). 
     The absorptive applicator assemblies  116  take the form of upper roller assemblies  233  and lower roller assemblies  253 . FIGS. 11-13 illustrate an upper roller assembly  233 . Each of the upper roller assemblies  233  may comprise a solid shaft  235  or hollow shaft (not shown) that has a roll bushing  237  pressed thereon at each of its end portions  240 . Another shaft bushing  246  is pressed onto the intermediate portion  242  of the shaft  235 . As can be seen in FIG. 13, bushings  237  and  246  are received within a liner  245  that is pressed into an elongated roller  247 . It will be appreciated that bushings  237  and  246  rotatably support solid shaft  235  within liner  245 . An upper roller assembly  233  further comprises a bushing  250  pressed onto the shaft  235  at one of the end portions  240 . A flange member  239  is pressed onto the other end of the solid shaft  235  and extends perpendicular thereto. The flange member  239  further includes a projection  251  which is supported by the bearing blocks  121  and prevents the solid shaft  235  from rotating. The shaft  235  and the bushings  237 ,  246  and  250  are rotatably received within the roller  247  and the liner  245  such that the roller  247  can rotate relative to the shaft  235 . The elongated roller  247  may be made of a woven mesh made from polypropylene, polyethylene or polyvinyl alcohol; however, a variety of materials can be used for the roller  247  as will be apparent to one of ordinary skill in the art. The shaft  235  may be made of polyvinylchloride; however, it will be apparent to one of ordinary skill that other materials may be used as well. Bushings  237 , 246  and  250  may be made of polypropylene; however, any material having suitable mechanical and chemical properties could also be used for the bushings  237 ,  246  and  250 . The shaft  235  is supported at its end portions  240  to the bearing block  121  wherein the solid shaft  235  and the flange member  239  are received within recesses of the bearing blocks  121 , shown in FIG.  3 . 
     FIGS. 14-16 illustrate a lower roller assembly  253  of the conveyorized electroplating device  110  shown in FIG. 3. A lower roller assembly  253  may include a solid shaft  255 , two roll bushings  261 , a shaft bushing  263 , a sprocket  265 , a liner  267 , and a roller  269 . The solid shaft  255  has two end portions  257  and an intermediate portion  259 . The roll bushings  261  are pressed onto the two end portions  257  of the shaft  255 . Similarly, the shaft bushing  263  is pressed onto the intermediate portion  259 . The sprocket  265  is pressed onto one end portion  257 . A liner  267  is pressed into a coaxial passage in roller  269  and is rotatably supported on the bushings  263  and  261 . The roller  269  may be made from woven mesh of polypropylene, polyethylene or polyvinyl alcohol or a variety of other materials apparent to one of ordinary skill in the art. The shaft  255 , the liner  267 , and the bushings  263  and  261  also may be made of the materials for the like parts stated above. The end portions  257  of the shaft  255  are received within recesses in the bearing block  121  (FIG. 3) and the sprocket  265  is engaged and rotated by a chain (not shown) to drive lower roller assemblies  253 . However, other conventional drive mechanisms can be used to drive the lower roller assemblies  253 . The chain is driven by a lower roller drive assembly  128 . The lower roller drive assembly  128  may be a DC motor, an AC motor, a stepper motor or a servo motor, 
     FIG. 17 is a top view of a drive assembly  150  and gripper assemblies  124 . FIG. 18 is a multiple layer longitudinal sectional view of the drive assembly  150  and gripper assemblies  124  shown in FIG.  17 . FIG. 19A is a horizontal sectional view of the drive assembly  150  and gripper assemblies  124  of the present invention shown in FIG.  17  and taken along line  19 — 19  in FIG.  17 . FIG. 20 is a sectional view of the gripper assemblies  124  illustrating the movement of the gripper assemblies  124  when the substrate  217  is being fed through the conveyorized electroplating device  110 . In FIGS. 18,  19 A and  20 , the gripper assemblies  124  are illustrated as a simplified form for clarity. In operation, a circuit board substrate  217  is inserted into the conveyorized device  110  at the input station  104  (shown in FIG.  1 ), fed onto the track  119  of one of the modules  102  (shown in FIG. 3) and is gripped along the length of one of its edges  219  by the gripper assembly  124  (FIGS. 17,  18 ,  19 A and  20 ). As shown in FIG. 17, as the gripper assemblies  124   a  round the corner of the drive assembly  150 , the substrate  217  is gripped by the gripper assembly  124   a  and is carried in direction A due to the motion of the chain  152 . As the gripper assembly  124   a  is about to turn at the opposing end of the drive frame  156  following the path of the chain  152 , the gripper assembly  124   a  will release the substrate  217  having carried the substrate  217  the length of the drive frame  156 . 
     Referring to FIGS. 18 and 20, for the pivotable panel support  172  of the gripper assembly to grasp the circuit board substrate  217 , the roller  206  engages a ramp  223  which is inclined in the downward direction B (FIG.  20 ). The ramp  223  is a bus bar  221 . As the gripper assembly  124  moves further in the direction A, the ramp  223  forces the roller  206  in direction B, which results in the T-shaped member  178  exerting a force on the housing biasing members  194  and being compressed in a direction B (see FIGS. 8,  10 B,  10 C and  10 D). FIG. 10A illustrates the gripper assembly  124  before it engages the ramp  223 . When the gripper assembly engages ramp  223  and even before a substrate  217  enters passageway  174  the seal  176  engages the pivotal panel support  172 . (FIG.  10 D). The housing biasing members  194  will compress before the first and second biasing members  200  and  202  because the housing biasing members  194  are weaker. As the ramp  223  (FIG. 20) further increases in a downward direction B, the force exerted on the roller  206  (FIGS. 8,  10 B,  10 C and  10 D) compresses the first and second biasing members  200  and  202 , resulting in the extension  212  moving from an unengaged position without a substrate  217  (FIG.  10 D), to an intermediate position (FIG. 10B) to a fully engaged position ( 10 C), wherein the extension  212  extends from opening  214  and makes contact with the substrate  217  which is received within passageway  174  (FIG.  10 C). Because the housing springs  194  are less stiff than the first and second biasing member  200  and  202 , the T-shaped member  178  will be compressed in direction B initially. Having the two different strength springs allows for the T-shaped member  178  to move in direction B resulting in the seal  176 , engaging the pivotal panel support  172  and the extension member  212  to remain within cavity  186  and thus, be protected from the plating solution until the substrate  217  is received within passageway  174  at which time the substrate  217  will engage the seal  176  (FIG. 10C) and thus isolate extension  212  from the plating solution. The extension  212  is in the unengaged position (FIG. 10A) when no force has been applied to the housing biasing members  194  on the first and second biasing members  200  and  202 . The extension is an unengaged position without a substrate when the roller engages the ramp  223  but no substrate  217  is present in the passageway  174  (FIG.  10 D). The extension  212  is in the intermediate position (FIG.  10 B), when the housing biasing members  194  are being compressed. The extension is in the engaged position when it is extending from the opening  214  (FIG.  10 C). 
     At the same time that rollers  206  of the gripper assemblies  124  are engaging the ramp  223 , the pivotable panel support  172  is riding across ledge  225  such that the ledge  225  supports the pivotable panel support  172  in the C direction. See FIG.  20 . Furthermore, when the roller contacts the ramp  223 , which is a bus bar  221 , electricity is supplied to the roller  206 . The electricity flows through the metallic roller  206 , through the first contact  197 , through the contact wire  204 , through the second contact  199  and through the extension  212 . When the extension  212  contacts the substrate  217 , the substrate is then electrified. While the gripper assemblies are gripping the substrate, moving it in direction A and electrifying the substrate, the plating solution is being pumped through the fluid bed assembly  112  from plating reservoir  111  (FIGS.  3 - 5 ). The plating solution enters inlet  136  and is diffused by the baffles  132  and forced through the electrified anode slots  148  where it then is applied to the upper roller assemblies  233  which are in contact with the substrate  217  and is transferred thereby to the substrate  217  which is in contact with the upper roller assemblies  233 . Both a DC current electroplating method may be used to plate the substrate or a pulse plating method may be used. One example of a pulse plating system that may be used is manufactured by Chemring Plating Systems of Kennett Square, Pa. 19348. The baffles  132  forces the plating solution to be evenly distributed along the anode  134  and exiting the anode evenly along the surface thereof. Without the baffles  132 , the plating solution would enter the inlet  136  and move directly to the closest holes  148  thus exiting the anode  134  at concentrated areas. 
     FIG. 19B is a diagrammatical sectional view of another embodiment of the drive assembly and gripper assembly having a cleaning device  350  for the extension  212 , which is the electrical contact. The cleaning device  350  comprises an abrasive disk  356 , a motor  352  and a spring loaded vertical actuator  354 . The abrasive disk  356  can be substantially comprised of a diamond dust mounted on a structure; however, many other abrasive surfaces may be used. The motor  352  may be an electrical motor, a pneumatic motor or other types of motors apparent to one of ordinary skill in the art. The spring loaded vertical actuator  354  may be a coil spring or other members that will absorb the downward force of the device  350 . The cleaning device is mounted on the return pass of the drive assembly  150 . As the gripper assembly  124  rides along the ramp  358 , the extension  212  is forced passed the seal  176  while at the same time the abrasive disk  356  is moved into contact in the direction F with the extension  212  by the spring loaded vertical actuator  354 . This contact results in the removal of unwanted plating or oxidation from the extension  212 . 
     This embodiment of the present invention places a relatively large amount of absorptive applicator assemblies  116  in contact with the substrate  217  and both the assemblies  116  and the substrate  217  in close proximity with the anode  134  which results in a high metallic ion exchange. Furthermore, the relatively large number of assemblies  116  in contact with the substrate provides for the desired plating of holes and/or openings in the substrate  217 . 
     As can be seen in FIG. 20, a ski-shaped device  227  can be substituted for the roller  206 . The ski-shaped device  227  can be made of a variety of metallic materials such as copper. 
     FIGS. 21-23 illustrate another embodiment of the conveyorized electroplating device  110  of the present invention. The conveyorized electroplating device system  100  comprises two fluid bed assemblies  112 , a lower anode assembly dam  277 , upper and lower bearing block supports  121 , absorptive applicator assemblies  116 , and portions of housing  108 . The conveyor device  114  previously discussed is also used in this embodiment; however, it has been omitted from FIGS. 21-23 for clarity purposes. The fluid bed assembly  112  shown in FIG. 23 comprises a manifold  130  and an anode  134 . The manifold  130  is a substantially rectangular member having an inlet  271 , a receptacle portion  131  and a mounting flange  273  (not shown) on opposing sides of the manifold  130 . The anode  134  consists of a substantially rectangular planar member fabricated from a material suitable for the material of the substrate having holes  148  extending therethorough. For example, if the substrate is to be plated with copper, the anode  134  may be copper and the plating solution may be a copper acid bath. Also the anode may be, for example, titanium or titanium with a coating. Furthermore, the anode  134  may be non-sacrificial and inert such as titanium or titanium with a coating and the plating solution may be a tin bath. However, one of ordinary skill will appreciate that a variety of anodes and plating solutions may be used. The anode  134  is connected to the manifold  130  at its periphery by stainless steel screws  275  and the fluid bed assembly  112  is then connected to the housing (not shown). 
     The lower anode assembly dam  277 , shown in FIG. 21, comprises four vertical walls forming a rectangular shape, wherein the opposing side walls define recesses  279 . The shafts  235  and  255  of the upper and lower roller assemblies  233  and  253  are received with the recesses  279 . The lower anode assembly dam  277  also has a cut-out portion  281  at one end thereof that receives the tubular inlet member  271  of the manifold  130 . The lower anode assembly dam  277  is supported by the fluid bed assembly  112  and connected to the anode  134  by fasteners (not shown). The vertical walls are notched to be received within the upper and lower bearing block supports  121 . See FIG.  22 . 
     The upper and lower roller assemblies  233  and  253 , shown in greater detail in FIGS. 11-16 and described above, are rotatably received within upper and lower bearing blocks supports  121 . The upper bearing blocks  121  have recesses  283  that rotatably receive a corresponding shaft  235  and flange member  239  of the upper roller assemblies  233 . Similarly, the lower bearing blocks  121  have recesses  183  (not shown) that are adapted to receive corresponding shaft  235  and flange member  239  of a corresponding lower roller assembly  253 . The lower and upper bearing block supports  121  are rigidly connected to the housing  108  by any conventional fasteners, including screws, bolts, rivets, etc. In operation, plating solution enters the fluid bed assembly  112  through inlet  271  of the manifold  130  and exits the fluid bed assembly  112  through the anode holes  148  and is applied to the roller assemblies  233  and  253  of the absorptive applicator assemblies  116 , wherein the plating solution will be transferred to both sides of the substrate as it moves over the absorptive applicator assemblies  116 . The lower anode assembly dam  277  prevents the plating solution from spilling over the sides of the fluid bed assembly  112  as it exits the anode holes  148  thus, redirecting the solution onto the absorptive applicator assemblies  116 . The lower anode assembly dam  277  creates a reservoir for the plating solution thus, keeping the roller assemblies  116  wet with the plating solution. This results in the substrate  217  also remaining wet with plating solution thus preventing “burning” of the substrate  217 . Burning is when the substrate  217  after being electroplated has darkened, uneven deposits associated with high current densities or a lack of metals to be plated or a combination of both. This burning can be prevented by keeping the substrate wet with plating solution. 
     FIG. 24 is a sectional view of another embodiment of the conveyorized electroplating device  110  of the present invention having absorptive applicator assemblies  116  in the form of strip or block members  285 . This embodiment comprises the lower roller assemblies  253 , as described above, positioned below the substrate  217  and block members  285  made of absorptive material being mounted over the holes  148  of the anode  134  such that the plating solution that is pumped through the fluid bed assembly  112  will exit the holes  148  in the anode  134  and be delivered to the substrate. The block members  285  may be made from polyethylene, polypropylene or polyvinyl alcohol or any other material that is flexible and absorbent and chemically compatible. In this embodiment, the block members  285  are in direct contact with the substrate; however the block members  285  may be spaced from the substrate. 
     FIGS. 25-27 illustrate another embodiment of the conveyorized electroplating device  110  of the present invention, wherein driven absorptive applicator assemblies  116  engage the bottom of the substrate  217  (FIG. 26) and the plating solution is applied from the bottom of the substrate  217  through the anode  134 . In this embodiment, only one fluid bed assembly  112  and one row of absorptive applicator assemblies  116  are used. The substrate  217  moves over the track  119  defined by the absorptive applicator assemblies  116 . The absorptive applicator assemblies  116  are positioned above the fluid bed assembly  112 . The fluid bed assembly  112  comprises a manifold  130 , several baffles  132  and an anode  134 , as described previously. The plating solution is pumped through the fluid bed assembly  112  exiting the anode  134  at the anode holes  148  and is applied to the absorptive applicator assemblies  116 . As can be seen in FIG. 26, the absorptive applicator assemblies  116  are spaced from the anode  134 ; however, the absorptive applicator assemblies  116  may also contact the anode  134 . 
     FIGS. 28-30 illustrate another embodiment of the conveyorized electroplating device  110  of the present invention, wherein the substrate  217  is positioned between two rows of the absorptive applicator assemblies  116  and the plating solution is applied to the top and bottom of the substrate  217 . This embodiment of the conveyorized electroplating device  110  comprises two fluid bed assemblies  112 , two rows of absorptive applicator assemblies  116 , the upper roller assemblies  233  and the lower roller assemblies  253 , wherein the lower roller assemblies  253  are driven members and the upper roller assemblies  233  are free to rotate. Each fluid bed assembly  112  comprises a manifold  130 , a plurality baffles  132  and an anode  134 , all of which have been described above. The substrate  217  is driven by the lower roller assemblies  253  and the conveyor device  114  (not shown for clarity purposes). The plating solution is applied to both sides of the substrate  217  by the fluid bed assemblies  112 . The solution is pumped out of the holes  148  of the anodes  134  onto the absorptive applicator assemblies  116 , which are in contact with the substrate  217 . Alternatively, the plating solution may be pumped through only one of the two fluid bed assemblies  112  thus, electroplating only one surface of the substrate  217 . This embodiment also includes two spray bars  248  each having spray nozzles  249  for wetting the substrate  217  with the plating solution prior to engaging the absorptive applicator assemblies  116 . By soaking the substrate prior to electroplating the substrate, the substrate is not susceptible to being depleted of solution during the electroplating process and thus, having an uneven “burnt” electroplated surface as a result. The spray bars  248  have nozzles  249  connected thereto which spray the plating onto the substrate  217 . The spray bars are fluidly connected to the plating solution reservoir  111 . 
     FIGS. 31-33 illustrate yet another embodiment of the conveyorized electroplating device  110  of the present invention, wherein the substrate  217  is positioned above the driven absorptive applicator assemblies  116  and the plating solution is supplied through the anode  134  positioned above the substrate  217 . In this embodiment, the conveyorized electroplating device  110  comprises one fluid bed assembly  112  positioned adjacent to the roller assemblies  116 . The plating solution is pumped through the fluid bed assembly  112  exiting the anode holes  148  onto the roller assemblies  116  which come in contact with the substrate  217 . 
     FIGS. 34-37 illustrate yet another embodiment of the conveyorized electroplating device of the present invention, wherein the substrate  217  is between upper and lower roller assemblies  233  and  253  and the plating solution is supplied through a fluid passageway defined by the upper and lower roller assemblies  233  and  253 . In this embodiment of a conveyorized electroplating device  110 , the plating solution is transported to the absorptive applicator assemblies  116  through a supply tubing system  300  such that the plating solution enters a fluid passageway  301  of the absorptive applicator assemblies  116  (FIG. 37) and is dispersed radially with respect to the absorptive applicator assemblies  116 . The anode  302  has a profile that conforms with the absorptive applicator assemblies  116  such that the anode  302  is in contact with absorptive applicator assemblies  116  or spaced a relatively small distance away therefrom. For example, in one embodiment of the present invention, the anode  302  can be spaced approximately 0.125 inches to 0.25 inches away from the absorptive applicator assemblies. This embodiment eliminates a manifold and baffles. The absorptive applicator assemblies  116  form two rows of absorptive applicator assemblies  116 , the upper and lower roller assemblies  233  and  253 , wherein the substrate  217  is fed therethrough and the lower roller assemblies  233  are driven. The tubing system  300  comprises multiple tubes  303  that supply plating solution to each of the upper roller assemblies  233  from a main line  304 . Although the plating solution is only being supplied to the substrate  217  through the upper roller assemblies  233 , the solution may also be supplied to the substrate  217  from both the upper and lower roller assemblies  233  and  253 . 
     FIGS. 38 and 39 illustrate upper roller assemblies  233  of the conveyorized electroplating device of the present invention shown in FIGS. 34-37. The upper roller assembly  233  is a tubular member defining a fluid passageway  306 . One of the multiple tubes  303  is connected to the fluid passageway  306  such that plating solution can be delivered from the plating solution source (not shown), through the main tube line  304 , through the multiple tubes  303  and into the fluid passageway  306 . The tubular member is made from porous plastic such as polyvinylchloride or ceramic such that the plating solution entering the fluid passageway  306  is dispersed radially through the tubular member to the substrate  217 . 
     FIGS. 40 and 41 illustrate another embodiment of an absorptive applicator assembly  116  of the conveyorized electroplating device  110  of the present invention having bristles  310  protruding from the circumference thereof and defining a fluid passageway  308  therethrough for delivering the plating solution to the substrate  217 . This embodiment of the absorptive applicator assembly  116  comprises a hollow shaft member  309  and a plurality of radially extending brush bristles  310 . The brush bristles  310  extend around the entire circumference of the shaft  309 . The brush bristles  310  comprise a U-shaped elongated channel member (not shown) within which the bristles extend. The channel member is crimped such that it is connected to the bristles and the elongated member is then wound around the shaft  309  where the channel member can be connected thereto by adhesive, clips or other fasteners. The tubes  303  supplying the plating solution are in fluid communication with the fluid passageway  308 . The plating solution is delivered to the fluid passageway and is dispersed outwardly onto the substrate  217  which is in contact therewith. The shaft  309  is made from a porous plastic that allows for the plating solution to be dispersed radially outward and through the plastic. The bristles  310  then supply the plating solution to the substrate. The bristles  310  may be made from polypropylene or any other suitable material. 
     FIGS. 42 and 43 illustrate yet another embodiment of an absorptive applicator assembly  116  of the conveyorized electroplating device  110  of the present invention having a flat brush and defining a fluid passageway  316  therethrough for delivering plating solution. In this embodiment, the absorptive applicator assemblies  116  each comprise a tubular member  314  defining a fluid passageway  316  and a longitudinal slot  318  that extends the length of the tubular member  314 . The absorptive applicator assemblies  116  further include a plurality of brush bristles  320  that extend radially from the tubular member  314  and cover a portion of the circumference of the tubular member  314  thus forming a flat brush. The plating solution is supplied from the multiple tubes  303 , to the fluid passageway  316  of the tubular member  314  and it is directed to the brush bristles  320  by the slotted portion  318  of the tubular member  314 . The bristles  320  engage the substrate  217  and apply the plating solution thereto. It will be appreciated that all of the absorptive applicator assemblies  116  illustrated in FIGS. 38-43 may be manufactured without a fluid passageway therein and thus, be adapted to be used in the embodiments of the present invention illustrated in FIGS. 1-33. 
     Although the present invention has been described in conjunction with preferred embodiments thereof, it is expected that many modifications and variations will be developed. This disclosure and the following claims are intended to cover all such modifications and variations.

Technology Classification (CPC): 2