Methods to stop copper attach by alkaline etching agents such as ammonia and monoethanol amine (MEA)

Abstract

A corrosive composition, such as an alkaline aqueous carbon dispersion, a cleaner, a cleaner conditioner, or a conditioner, comprises a corrosion inhibitor, e.g., benzotriazole. The corrosion inhibitor is present in an amount effective to reduce or stop the dissolution of metal from a metallic surface, such as a printed circuit board, in contact with the composition. A method to reduce or stop the dissolution of metal from a metallic surface in contact with a corrosive composition, and a method to stabilize or recover a corrosive composition containing metal contaminants by adding an effective amount of a corrosion inhibitor to the corrosive composition.

1 . A method to reduce the dissolution of metal from a metallic surface in a corrosive composition, comprising: 
 providing a corrosive composition;    adding an effective amount of a corrosion inhibitor to said corrosive composition to reduce its corrosiveness; and    applying said composition to said metallic surface.    
     
     
         2 . The method of  claim 1  wherein said amount of said corrosion inhibitor is from about 1 ppm to about 1% by weight.  
     
     
         3 . The method of  claim 1  wherein said amount of said corrosion inhibitor is from about 50 ppm to about 4000 ppm by weight.  
     
     
         4 . The method of  claim 1  wherein said amount of said corrosion inhibitor is from about 200 ppm to about 600 ppm by weight.  
     
     
         5 . The method of  claim 1  wherein said corrosion inhibitor is at least one of an imidazole, a triazole, an indole, an azole, a thiazole, or a tetrazole.  
     
     
         6 . The method of  claim 1  wherein said corrosion inhibitor is selected from the group consisting of benzotriazole, sodium mercaptobenzothiazole, thiourea, tolyltriazole, 3-amino-1,2,4-triazole, and combinations thereof.  
     
     
         7 . The method of  claim 1  wherein said metal is copper.  
     
     
         8 . A method to stabilize or recover a corrosive composition, comprising: 
 presenting a corrosive composition;    presenting a metallic surface to said corrosive composition under conditions effective to dissolve metal from said metallic surface;    dissolving metal from said metallic surface in said corrosive composition;    adding a corrosion inhibitor to said corrosive composition in an amount effective to stabilize or recover said corrosive composition.    
     
     
         9 . The method of  claim 8  wherein said corrosion inhibitor is added to prevent gel formation in said corrosive composition.  
     
     
         10 . The method of  claim 8  wherein said corrosion inhibitor is added after gel formation has occurred in said corrosive composition.  
     
     
         11 . The method of  claim 10  wherein said corrosion inhibitor is added in an amount effective to at least partially reverse said gel formation.  
     
     
         12 . The method of  claim 8  wherein said amount of said corrosion inhibitor is from about 1 ppm to about 1% by weight.  
     
     
         13 . The method of  claim 8  wherein said amount of said corrosion inhibitor is from about 50 ppm to about 4000 ppm.  
     
     
         14 . The method of  claim 8  wherein said amount of said corrosion inhibitor is from about 200 ppm to about 600 ppm  
     
     
         15 . The method of  claim 8  wherein said corrosion inhibitor is at least one of an imidazole, a triazole, an indole, an azole, a thiazole, or a tetrazole.  
     
     
         16 . The method of  claim 8  wherein said corrosion inhibitor is selected from the group consisting of benzotriazole, sodium mercaptobenzothiazole, thiourea, tolyltriazole, 3-amino-1,2,4-triazole, and combinations thereof.  
     
     
         17 . The method of  claim 8  wherein said metal is copper.