Method and apparatus for managing plating interruptions

Abstract

A plating method and apparatus including at least one plating bath including a plating solution used for plating at least one workpiece and a source providing a first current, wherein the first current is supplied to the plating solution when plating the at least one workpiece, and providing a second current, lower than the first current, wherein the second current is supplied to the plating solution during an interruption. The plating method and apparatus may include at least one main bath, at least one main anode, at least one auxiliary bath, at least one auxiliary anode, and/or a conveying unit. A portion of the conveying unit or the at least one workpiece may act as a cathode or anode. The plating method and apparatus may continuously expose a workpiece to a plating solution.

What is claimed is:  
     
         1 . A plating method comprising: 
 immersing at least one workpiece in a plating solution held in at east one plating bath;    supplying a plating current to at least one anode in the plating solution to plate the at least one workpiece;    decreasing the plating current supplied to the at least one anode upon interruption of the plating; and    returning the plating current a previous amount after the interruption has ended to resume plating.    
     
     
         2 . The plating method of  claim 1 , wherein, the plating current is decreased to 5% to 40% of an original value.  
     
     
         3 . The plating method of  claim 1 , wherein the plating solution includes tin and bismuth and a tin-bismuth layer is plated on the at least one workpiece.  
     
     
         4 . A plating apparatus comprising: 
 a plurality of main plating baths which are aligned and each holding a plating solution;    a plurality of anodes in the plating solution of the plurality of main plating baths;    a plurality of auxiliary plating baths interconnected between the plurality of main plating baths for allowing the plating solution to flow therethrough;    a conveying unit, which sequentially conveys workpieces to the plurality of main plating baths and the plurality of auxiliary plating baths to be plated; and    a power source for selectively supplying a plating current to the plurality of anodes which is reduced when the plating is interrupted.    
     
     
         5 . The plating apparatus of  claim 4 , further comprising a plurality of auxiliary anodes connected to the power source and disposed in the plurality of auxiliary plating baths.  
     
     
         6 . The plating apparatus of  claim 5 , wherein the plurality of auxiliary anodes are commonly connected to the plurality of anodes which are connected to the power source.  
     
     
         7 . The plating apparatus of  claim 4 , wherein each of the plurality of auxiliary anodes extends into a corresponding one of the plurality of auxiliary plating baths.  
     
     
         8 . The plating apparatus of  claim 4 , further comprising a plurality of sensors, each inserted into one of the plurality of auxiliary plating baths for sensing the plating solution flowing into the plurality of auxiliary plating baths.  
     
     
         9 . The plating apparatus of  claim 4 , wherein the plating current is decreased to 5% to 40% of an original value.  
     
     
         10 . A plating method of using a plating apparatus, which includes a plurality of main plating baths aligned for holding a plating solution, a plurality of anodes in the plating solution of the plurality of main plating baths, a plurality of auxiliary plating baths interconnected between the plurality of main plating baths for allowing the plating solution to flow therethrough, a conveying unit acting as a cathode to the plurality of anodes for sequentially conveying workpieces to the plurality of main plating baths and the plurality of auxiliary plating baths, and a power source for applying current to the plurality of anodes, the plating method comprising: 
 sequentially and continuously supplying the workpieces to the plating apparatus, which includes using the conveying unit, to pass the workpieces through the plurality of main plating baths and the plurality of auxiliary plating baths;    supplying a plating current provided by the power source to the plurality of anodes to plate the workpieces;    reducing the plating current supplied by the power source upon interruption of the plating; and    returning the plating current to a previous amount after the interruption has ended to resume plating.    
     
     
         11 . The plating method of  claim 10 , wherein the plating solution includes tin and bismuth, and a tin-bismuth layer is plated on the workpieces.  
     
     
         12 . The plating method of  claim 10 , wherein, the plating current is decreased to 5 to 40% of an original value.  
     
     
         13 . The plating method of  claim 10 , wherein the plating apparatus further includes a plurality of auxiliary anodes disposed inside the plurality of auxiliary plating baths, and the plating current supplied by the power source when an interruption occurs is applied both to the plurality of anodes and the plurality of auxiliary anodes.  
     
     
         14 . The plating method of  claim 13 , wherein the plating apparatus further includes a plurality of auxiliary anodes, each of the plurality of auxiliary anodes extending into a corresponding one of the plurality of auxiliary plating baths, and the plating current supplied by the power source is applied both to the plurality of anodes and the plurality of auxiliary anodes.  
     
     
         15 . An apparatus comprising: 
 at least one plating bath including a plating solution used for plating at least one workpiece; and    a source providing a first current, wherein the first current is supplied to the plating solution when plating the at least one workpiece, and providing a second current, lower than the first current, wherein the second current is supplied to the plating solution during an interruption.    
     
     
         16 . The apparatus of  claim 15 , wherein the source provides the first current after the interruption has ended.  
     
     
         17 . The apparatus of  claim 15 , wherein the plating solution includes tin and bismuth and a tin-bismuth layer is plated on the at least one workpiece.  
     
     
         18 . The apparatus of  claim 15 , wherein the second current is 5% to 40% of the first current.  
     
     
         19 . The apparatus of  claim 15 , wherein the second current is low enough to not induce plating and high enough so as to not induce at least one of substitution and precipitation of elements in the plating solution.  
     
     
         20 . A method comprising: 
 plating at least one workpiece by passing the at least one workpiece through at least one plating bath; and    changing a first current to a second current during an interruption in the plating.    
     
     
         21 . The method of  claim 20 , further comprising: 
 increasing the second current to the first current after the interruption has ended.    
     
     
         22 . The method of  claim 20 , wherein the plating further includes 
 submerging the at least one workpiece in the plating solution, and    exposing the first current to the workpiece in the plating solution.    
     
     
         23 . The method of  claim 22 , wherein the plating solution includes tin and bismuth and the plating forms a tin-bismuth layer on the at least one workpiece.  
     
     
         24 . The method of  claim 20 , wherein the second current is 5% to 40% of the first current.  
     
     
         25 . The method of  claim 20 , wherein the second current is low enough to not induce plating and high enough so as to not induce at least one of substitution and precipitation of elements in the plating solution.  
     
     
         26 . An apparatus comprising: 
 at least one main plating bath; and    at least one auxiliary plating bath, arranged such that a plating solution may flow from the at least one main plating bath into the at least one auxiliary plating bath, wherein at least one workpiece plated by the apparatus is not exposed to the environment outside of the plating bath solution.    
     
     
         27 . A method comprising: 
 providing at least one plating bath and at least one auxiliary bath such that a plating solution may flow from the at least one main plating bath into the at least one auxiliary plating bath; and    passing at least one workpiece through the at least one main plating bath and the at least one auxiliary plating bath such that the at least one workpiece is not exposed to the environment outside of the plating solution.    
     
     
         28 . An apparatus comprising: 
 at least one main plating bath;    at least one auxiliary plating bath, arranged such that a plating solution, with a current applied thereto, may flow from the at least one main plating bath into the at least one auxiliary plating bath; and    a conveying unit for providing at least one workpiece to the plating solution with the current applied thereto, at least a portion of the conveying unit or the at least one workpiece acting as one of a cathode and anode to conduct the current.    
     
     
         29 . A method comprising: 
 passing at least one workpiece though at least one plating bath and at least one auxiliary bath arranged such that a plating solution, with a current applied thereto, may flow from the at least one main plating bath into the at least one auxiliary plating bath; and    conducting the current using at least a portion of the conveying unit or the at least one workpiece as one of a cathode and anode.