Cleaning composition

Abstract

A composition composed of a persulfate, boric acid, a fluorine containing acid and an inorganic acid. Adjuvants also may be included in the composition. The composition may be employed as a microetch solution in the fabrication of microelectronic packages.

What is claimed is:  
     
         1 . A composition comprising a persulfate, a fluorine containing acid, and boric acid or a salt of boric acid or mixtures thereof.  
     
     
         2 . The composition of  claim 1 , wherein the persulfate comprises sodium monopersulfate, potassium monopersulfate, or mixtures thererof.  
     
     
         3 . The composition of  claim 1 , wherein the fluorine containing acid comprises hydrofluoric acid, fluoroboric acid, fluorosilic acid, or mixtures thereof.  
     
     
         4 . The composition of  claim 1 , wherein the salts of boric acid comprise lithium, sodium, potassium salts of boric acid, or mixtures thereof.  
     
     
         5 . The composition of  claim 1 , further comprising an additional inorganic acid.  
     
     
         6 . The composition of  claim 5 , wherein the additional inorganic acid comprises sulfuric acid, phosphoric acid, phosphorous acid, or mixtures thererof.  
     
     
         7 . The composition of  claim 1 , further comprising one or more adjuvants.  
     
     
         8 . A composition comprising potassium monopersulfate, fluoroboric acid, boric acid and sulfuric acid.  
     
     
         9 . A method of preparing a composition comprising: 
 a) providing an aqueous solution of a persulfate;    b) mixing a concentrate comprising boric acid or a salt of boric acid and a fluoride containing acid with the aqueous solution of the persulfate to form a first mixture; and    c) mixing an additional inorganic acid with the first mixture to form a stable second mixture.    
     
     
         10 . The method of  claim 9 , wherein the persulfate comprises an alkali monopersulfate.  
     
     
         11 . The method of  claim 9 , wherein the fluoride containing acid comprises fluoroboric acid.  
     
     
         12 . The method of  claim 9 , wherein the additional inorganic acid is sulfuric acid.  
     
     
         13 . The method of  claim 9 , further comprising the step of adding at least one adjuvant to the stable second mixture.  
     
     
         14 . A method of microetching a metal comprsing: contacting a surface of a metal with a microetch solution comprising a persulfate, boric acid or a salt of boric acid, a fluoride containing acid and an additional inorganic acid to remove a portion of the surface of the metal.  
     
     
         15 . The method of  claim 14 , wherein the persulfate comprises an alkali monopersulfate.  
     
     
         16 . The method of  claim 14 , wherein the fluorine containing acid comprises fluoroboric acid.  
     
     
         17 . The method of  claim 14 , wherein the metal comprises copper.  
     
     
         18 . the method of  claim 14 , wherein the microetching is performed at a temperature of 80° F. to 100° F.  
     
     
         19 . The method of  claim 17 , wherein the copper saturation and crystallization concentration in the microetch solution is greater than 40 grams/Liter.  
     
     
         20 . The method of  claim 14 , wherein the metal is part of a printed circuit board.