Apparatus and method for improved electroforming

Abstract

The present invention includes an apparatus and method for providing optimal uniformity of deposition during an electroplating process. The system may include an agitating device which is configured to provide agitation to the anode basket, a bias current distributed over a control grid (e.g., titanium mesh) which is disposed between the anode and cathode, wherein the control grid is configured to substantially reduce the variation in the electric field across the cathode, a cathode which includes a backplate having a contact ring wherein the contact ring includes a device configured to increase the pressure of the contact ring against the backplate and/or a cathode mounted on a lead screw for providing axial movement of the cathode along an axis normal to the anode.

1 . An apparatus for facilitating the uniformity of deposition in an electroforming process, wherein said apparatus includes an anode basket, a cathode facing said anode and a control grid between said anode and cathode, wherein said control grid is configured to substantially reduce the variation in the electric field across said cathode:  
     
     
         2 . The apparatus of  claim 1 , wherein at least a portion of said control grid is comprised of a titanium mesh.  
     
     
         3 . The apparatus of  claim 1 , wherein a polypropylene mesh is disposed between said control grid and said cathode, wherein said polypropylene mesh is configured to substantially filter at least a portion of sludge and substantially restrict at least a portion of said sludge from adhering to said cathode.  
     
     
         4 . The apparatus of  claim 1 , wherein a baffle is disposed between said control grid and said cathode, wherein said baffle is configured for substantially focusing and controlling the flatness of at least a portion of an electrical current field that contacts said cathode.  
     
     
         5 . The apparatus of  claim 1 , further including a circuit which is configured to distribute a bias current over said control grid.  
     
     
         6 . The apparatus of  claim 5 , wherein said circuit includes a power supply, an ammeter, a resistor, wherein said power supply is coupled to said cathode and said anode and said power supply is further coupled to said ammeter, which is coupled to said resistor, thereby allowing for adjustment of said bias current over said control grid and monitoring adjustments using said ammeter.  
     
     
         7 . An apparatus for controlling the uniformity of deposition in an electroforming process, said apparatus including an anode, a cathode assembly facing said anode, said cathode assembly comprising a backplate having a contact ring, said contact ring includes a device configured to increase the pressure of said contact ring against said backplate.  
     
     
         8 . The apparatus of  claim 7 , wherein said device configured to increase the pressure of said contact ring against said backplate includes a spring element.  
     
     
         9 . An apparatus for facilitating the uniformity of deposition in an electroforming process, wherein said apparatus includes a rotating anode and at least one of a stationary cathode and a rotating cathode facing said anode.  
     
     
         10 . An apparatus for facilitating the uniformity of deposition in an electroforming process, wherein said apparatus includes an anode basket, a cathode facing said anode and an agitating device which is configured to provide agitation to said anode basket.  
     
     
         11 . The apparatus of  claim 10 , wherein said agitating device includes a vibrator motor configured to provide vibration in the ultrasonic frequency range.  
     
     
         12 . An apparatus for facilitating the uniformity of deposition in an electroforming process, wherein said apparatus includes: 
 an anode;    a cathode facing said anode;    an agitating device which is configured to provide agitation to said anode basket;    a control grid between said anode and cathode, wherein said control grid is configured to substantially reduce the variation in the electric field across said cathode, said control grid coupled to a circuit which is configured to distribute a bias current over said control grid; and,    said cathode comprising a backplate having a contact ring, said contact ring includes a device configured to increase the pressure of said contact ring against said backplate.    
     
     
         13 . The apparatus of  claim 12  further including said cathode being mounted on a lead screw for providing axial movement of said cathode along an axis normal to said anode to facilitate uniform deposition by optimizing said distance to compensate for factors affecting the uniformity of said electroforming process.  
     
     
         14 . The apparatus of  claim 13  further comprising a servo motor operatively connected to said lead screw, said servo motor communicating with a computer, said computer being adapted to control said axial movement of said cathode assembly.  
     
     
         15 . The apparatus of  claim 12  further including: 
 said backplate having a base with a recess which holds a metallic cup;  
 said metallic cup configured for holding a mandrel having a front face to be plated;  
 said clamping ring pivotally attached to said backplate, said clamping ring configured to hold said mandrel against said backplate; and  
 a contact ring within said backplate, said contact ring configured to transfer current to said mandrel, said contact ring adapted to abut the front face of said mandrel.  
 
     
     
         16 . The apparatus of  claim 12 , wherein said base has at least one O-ring between said base and said clamping ring, said O-ring attached to said backplate and configured to impede the migration of processing solution between said clamping ring and said base.  
     
     
         17 . The apparatus of  claim 12 , wherein said clamping ring includes at least one locking device for providing pressure between said clamping ring and said backplate.  
     
     
         18 . The apparatus of  claim 12 , wherein said contact ring includes a beveled inner rim adjacent said front face of said mandrel to simplify separation of said contact ring from said mandrel.