Fixtureless vertical paddle electroplating cell

Abstract

A submersible assembly for exposing respective front surfaces of different work-pieces to an electroplating bath as a partial respective electrodes thereof, while protecting opposing, rear surfaces of the work-pieces from the bath. The assembly includes a wall, having a front surface also partially forming a first electrode of the bath, and having an opening smaller in size than the perimeter of a work-piece while substantially corresponding in size to the portion of the front surface of the work-piece to be exposed to the bath. The assembly also includes a chuck mechanism for applying pressure against the rear surface of the work-piece to thereby hold the work-piece against a rear surface of the wall and create a fluid-tight seal between the rear surface of the wall and the perimeter of the front surface of the work-piece, thereby exposing the front surface of the work-piece to the bath while protecting the rear surface of the work-piece from exposure to the bath.

1 . A submersible assembly for exposing respective front surfaces of different work-pieces to an electroplating bath as a partial respective electrode thereof, while protecting opposing, rear surfaces of the work-pieces from the bath, the submersible assembly comprising: 
 a wall, having a front surface also partially forming a first electrode of the bath, and having an opening smaller in size than the perimeter of a work-piece while substantially corresponding in size to the portion of the front surface of the work-piece to be exposed to the bath;    a chuck mechanism for applying pressure against the rear surface of the work-piece to thereby hold the work-piece against a rear surface of the wall and create a fluid-tight seal between the rear surface of the wall and the perimeter of the front surface of the work-piece, thereby exposing the front surface of the work-piece to the bath while protecting the rear surface of the work-piece from exposure to the bath.    
   
   
       2 . The submersible assembly of  claim 1 , wherein the opening has a recess formed about its perimeter at the rear surface of the wall, facing away from the bath, and into which the work-piece can be removably positioned.  
   
   
       3 . The submersible assembly of  claim 2 , wherein the recess is deep enough to allow the front surface of the work-piece to be substantially co-planar with the front surface of the wall.  
   
   
       4 . The submersible assembly of  claim 3 , further comprising at least one thief on the front surface of the wall.  
   
   
       5 . The submersible assembly of  claim 1 , further comprising additional walls forming a submersible compartment for fluid-tight submersion into the electrolyte bath and into which the work-pieces can be removably positioned.  
   
   
       6 . The submersible assembly of  claim 5 , further comprising a bellows surrounding the chuck mechanism and for sealing the chuck mechanism within the compartment from any fluid which may invade the compartment.  
   
   
       7 . The submersible assembly of  claim 5 , in combination with a primary electroplating cell containing the electroplating bath, the combination comprising: 
 mechanical means to align the submersible assembly within the primary cell; and    electrical means to energize both the submersible assembly and the primary cell.    
   
   
       8 . The submersible assembly of  claim 7 , wherein the work-piece comprises an integrated circuit wafer.  
   
   
       9 . The submersible assembly of  claim 1 , wherein the work-piece comprises an integrated circuit wafer.  
   
   
       10 . A method for exposing respective front surfaces of different work-pieces to an electroplating bath, while protecting opposing, rear surfaces of the work-pieces from the bath, the method comprising: 
 using a submersible assembly as a partial respective electrode of the electroplating bath; the assembly comprising: 
 a wall, having a front surface also partially forming a first electrode of the bath, and having an opening smaller in size than the perimeter of a work-piece while substantially corresponding in size to the portion of the front surface of the work-piece to be exposed to the bath;  
 a chuck mechanism for applying pressure against the rear surface of the work-piece to thereby hold the work-piece against a rear surface of the wall and create a fluid-tight seal between the rear surface of the wall and the perimeter of the front surface of the work-piece, thereby exposing the front surface of the work-piece to the bath while protecting the rear surface of the work-piece from exposure to the bath.  
   
   
   
       11 . The method of  claim 10 , wherein the opening has a recess formed about its perimeter at the rear surface of the wall, facing away from the bath, and into which the work-piece can be removably positioned.  
   
   
       12 . The method of  claim 11 , wherein the recess is deep enough to allow the front surface of the work-piece to be substantially co-planar with the front surface of the wall.  
   
   
       13 . The method of  claim 12 , wherein the assembly further comprises at least one thief on the front surface of the wall.  
   
   
       14 . The method of  claim 10 , wherein the assembly further comprises additional walls forming a submersible compartment for fluid-tight submersion into the electrolyte bath and into which the work-pieces can be removably positioned.  
   
   
       15 . The method of  claim 14 , wherein the assembly further comprises a bellows surrounding the chuck mechanism and for sealing the chuck mechanism within the compartment from any fluid which may invade the compartment.  
   
   
       16 . The method of  claim 14 , in combination with a method for operating a primary electroplating cell containing the electroplating bath, the method comprising: 
 aligning the submersible assembly within the primary cell; and    energizing both the submersible assembly and the primary cell.    
   
   
       17 . The method of  claim 16 , wherein the work-piece comprises an integrated circuit wafer.  
   
   
       18 . The method of  claim 10 , wherein the work-piece comprises an integrated circuit wafer.