Microetchant for copper and method for producing wiring board

Abstract

Disclosed are: a microetching agent which can form roughened shapes less affected by differences in the crystallinity of the copper and with which roughened shape excellent in terms of adhesiveness to resins, etc. can be formed on either electrolytic copper or rolled copper; and a method for producing a wiring board which includes a step of roughening a copper surface using the microetching agent. In the present invention, the microetching agent for copper is an acidic aqueous solution containing an inorganic acid, a cupric ion source, a halide ion source, and a polymer. The polymer has a functional group containing a nitrogen atom. It is preferable that the microetching agent contain a sulfate ion source.

1 . A microetching agent for copper that is capable of roughening copper surface,
 the microetching agent is an acidic aqueous solution comprising: an inorganic acid; a cupric ion source; a halide ion source; a sulfate ion source; and a polymer, wherein   the polymer is a water-soluble polymer having a weight-average molecular weight of 1000 or more, and is selected from a group consisting of: a polymer having a quaternary ammonium group in a side chain, and a polymer having a repeating unit represented by the following formula (V):   
       
         
           
           
               
               
           
         
         
           wherein in the formula (V), R 14  is a hydrogen atom or a chain or cyclic hydrocarbon group optionally having a substituent; m is an integer of 0 to 2; X 12  and X 13  are each independently a single bond or a divalent linking group. 
         
       
     
     
         2 . The microetching agent according to  claim 1 , wherein a molar concentration of the cupric ion source is 0.05 mol/L or more 
     
     
         3 . The microetching agent according to  claim 1 , wherein a molar concentration of the halide ion source is 0.01 to 4 mol/L. 
     
     
         4 . The microetching agent according to  claim 1 , wherein a molar concentration of the cupric ion source is 0.2 times or more as large as a molar concentration of the halide ion source. 
     
     
         5 . The microetching agent according to  claim 1 , wherein a molar concentration of the sulfate ion source is 0.02 mol/L or more. 
     
     
         6 . The microetching agent according to  claim 1 , wherein the inorganic acid contains at least one selected from a group consisting of sulfuric acid and hydrohalic acid. 
     
     
         7 . The microetching agent according to  claim 1 , wherein a concentration of the polymer is 0.002 to 1 g/L. 
     
     
         8 . (canceled) 
     
     
         9 . A method for producing a wiring board including a copper layer,
 the method comprising roughening the copper layer by bringing a microetching agent into contact with a surface of the copper layer,   wherein   the microetching agent is an acidic aqueous solution comprising: an inorganic acid; a cupric ion source; a halide ion source; a sulfate ion source; and a polymer,   the polymer is a water-soluble polymer having a weight-average molecular weight of 1000 or more, and is selected from a group consisting of: a polymer having a quaternary ammonium group in a side chain, and a polymer having a repeating unit represented by the following formula (V):   
       
         
           
           
               
               
           
         
         
           wherein in the formula (V), R 14  is a hydrogen atom or a chain or cyclic hydrocarbon group optionally having a substituent; m is an integer of 0 to 2; X 12  and X 13  are each independently a single bond or a divalent linking group. 
         
       
     
     
         10 . The method for producing a wiring board according to  claim 9 , wherein the surface of the copper layer that is brought into contact with the microetching agent is rolled copper. 
     
     
         11 . The method for producing a wiring board according to  claim 9 , wherein
 a replenishing liquid is added into the microetching agent during the roughening the copper layer,   the replenishing liquid is an acidic aqueous solution comprising of an inorganic acid, a halide ion source, and a polymer, and   the polymer in the replenishing liquid is a water-soluble polymer having a weight-average molecular weight of 1000 or more, and is selected from a group consisting of: a polymer having a quaternary ammonium group in a side chain, and a polymer having a repeating unit represented by the following formula (V):   
       
         
           
           
               
               
           
         
         wherein in the formula (V), R 14  is a hydrogen atom or a chain or cyclic hydrocarbon group optionally having a substituent; m is an integer of 0 to 2; X 12  and X 13  are each independently a single bond or a divalent linking group. 
       
     
     
         12 . The method for producing a wiring board according to  claim 9 , wherein a molar concentration of the cupric ion source in the microetching agent is 0.05 mol/L or more 
     
     
         13 . The method for producing a wiring board according to  claim 9 , wherein a molar concentration of the halide ion source in the microetching agent is 0.01 to 4 mol/L. 
     
     
         14 . The method for producing a wiring board according to  claim 9 , wherein a molar concentration of the cupric ion source is 0.2 times or more as large as a molar concentration of the halide ion source in the microetching agent. 
     
     
         15 . The method for producing a wiring board according to  claim 9 , wherein a molar concentration of the sulfate ion source in the microetching agent is 0.02 mol/L or more. 
     
     
         16 . The method for producing a wiring board according to  claim 9 , wherein the inorganic acid in the microetching agent contains at least one selected from a group consisting of sulfuric acid and hydrohalic acid. 
     
     
         17 . The method for producing a wiring board according to  claim 9 , wherein a concentration of the polymer in the microetching agent is 0.002 to 1 g/L.