Method and apparatus for controlling electrolytic solution

Abstract

An electrolytic solution control method can control the composition of an electrolytic solution efficiently with high precision, and can remove a partially decomposed product of an organic component from an electrolytic solution. The electrolytic solution control method includes storing an electrolytic solution containing an organic component and an inorganic component in an electrolytic solution storage tank while controlling and keeping the electrolytic solution at a predetermined composition, adjusting an inorganic component of the waste electrolytic solution after use in electrolytic processing in an electrolytic processing apparatus, and then returning the waste electrolytic solution to the electrolytic solution storage tank.

1 . An electrolytic solution control method comprising: 
 storing an electrolytic solution containing an organic component and an inorganic component in an electrolytic solution storage tank while controlling and keeping the electrolytic solution at a predetermined composition;    adjusting an inorganic component of the waste electrolytic solution after use in electrolytic processing in an electrolytic processing apparatus; and then    returning the waste electrolytic solution to the electrolytic solution storage tank.    
     
     
         2 . The electrolytic solution control method according to  claim 1 , wherein the adjustment of the inorganic component is effected by electrolytic processing carried out by providing a cathode chamber and an anode chamber which are separated by an ion exchanger, and using the waste electrolytic solution as an anode liquid.  
     
     
         3 . The electrolytic solution control method according to  claim 2 , wherein the ion exchanger is an ion-exchange membrane or ion-exchange fabric having monovalent cation selectivity.  
     
     
         4 . The electrolytic solution control method according to  claim 2 , wherein a soluble electrode is used as an anode in the electrolytic processing of the waste electrolytic solution, and the current density at the anode is 10 to 100 mA/cm 2 .  
     
     
         5 . The electrolytic solution control method according to  claim 2 , wherein the concentration of metal ions in the waste electrolytic solution is detected during the electrolytic processing so as to adjust the amount of electric current in the electrolytic processing.  
     
     
         6 . The electrolytic solution control method according to  claim 2 , wherein an inorganic acid is used as a cathode liquid in the electrolytic processing of the waste electrolytic solution, and the electric conductivity of the cathode liquid is detected and adjusted.  
     
     
         7 . The electrolytic solution control method according to  claim 2 , wherein pure water is used as a cathode liquid in the electrolytic processing of the waste electrolytic solution, and another ion exchanger is interposed between the cathode and said ion exchanger.  
     
     
         8 . The electrolytic solution control method according to  claim 1 , wherein the electrolytic processing apparatus is a plating apparatus which uses as an anode an insoluble electrode or an electrode not containing phosphorus.  
     
     
         9 . An electrolytic solution control method comprising: 
 storing an electrolytic solution containing an organic component and an inorganic component in an electrolytic solution storage tank while controlling and keeping the electrolytic solution at a predetermined composition;    removing at least part of the organic component of the waste electrolytic solution after use in electrolytic processing in an electrolytic processing apparatus; and then    returning the waste electrolytic solution to the electrolytic solution storage tank.    
     
     
         10 . The electrolytic solution control method according to  claim 9 , wherein the organic component is at least one of an organic polymer compound, a sulfur compound and a nitrogen compound.  
     
     
         11 . The electrolytic solution control method according to  claim 9 , wherein the removal of the organic component is carried out by using an adsorbent.  
     
     
         12 . The electrolytic solution control method according to  claim 9 , wherein the removal of the organic component is carried out utilizing oxidation and decomposition of the organic component.  
     
     
         13 . The electrolytic solution control method according to  claim 9 , wherein particles are removed from the waste electrolytic solution after the removal of the organic component.  
     
     
         14 . The electrolytic solution control method according to  claim 9 , wherein the electrolytic processing apparatus is a plating apparatus which uses as an anode an insoluble electrode or an electrode not containing phosphorus.  
     
     
         15 . An electrolytic solution control apparatus comprising: 
 an electrolytic solution storage tank for storing an electrolytic solution containing an organic component and an inorganic component therein while controlling and keeping the electrolytic solution at a predetermined composition; and    an inorganic component adjustment apparatus for adjusting an inorganic component of the waste electrolytic solution after use in electrolytic processing in an electrolytic processing apparatus, and then returning the waste electrolytic solution to the electrolytic solution storage tank.    
     
     
         16 . The electrolytic solution control apparatus according to  claim 15 , wherein the inorganic component adjustment apparatus is designed to supply metal ions to the waste electrolytic solution utilizing electrolysis.  
     
     
         17 . The electrolytic solution control apparatus according to  claim 15 , further comprising: 
 an inorganic component analyzer for analyzing the inorganic component of the waste electrolytic solution introduced into the inorganic component adjustment apparatus, and feeding back the analytical results to the inorganic component adjustment apparatus.    
     
     
         18 . The electrolytic solution control apparatus according to  claim 15 , wherein the electrolytic processing apparatus is a plating apparatus which employs as an anode an insoluble electrode or an electrode not containing phosphorus.  
     
     
         19 . An electrolytic solution control apparatus comprising: 
 an electrolytic solution storage tank for storing an electrolytic solution containing an organic component and an inorganic component therein while controlling and keeping the electrolytic solution at a predetermined composition; and    an organic component removal apparatus for removing at least part of the organic component of the waste electrolytic solution after use in electrolytic processing in an electrolytic processing apparatus, and then returning the waste electrolytic solution to the electrolytic solution storage tank.    
     
     
         20 . The electrolytic solution control apparatus according to  claim 19 , wherein the organic component removal apparatus includes an organic component oxidation/decomposition section for oxidizing and decomposing the organic component, and an organic component adsorption/removal section for removing the organic component by adsorption.  
     
     
         21 . The electrolytic solution control apparatus according to  claim 19 , further comprising: 
 a filter for removing particles, located downstream of the organic component removal apparatus.    
     
     
         22 . The electrolytic solution control apparatus according to  claim 19 , wherein the electrolytic processing apparatus is a plating apparatus which employs as an anode an insoluble electrode or an electrode not containing phosphorus.