Method of forming NiP nonmagnetic film and method of manufacturing magnetic head using the film

Abstract

The method is capable of easily and securely forming a NiP nonmagnetic film. In the method of forming the NiP nonmagnetic film by electrolytic plating, the electrolytic plating is performed in NiP plating solution consisting of: a reagent for supplying nickel ions; a reagent for supplying phosphorus ions; and a reagent including carboxyl groups. For example, sulfates and chloride salts of nickel, etc. may be use as the reagent for supplying nickel ions; phosphorus acid, sodium phosphite, etc. may be used as the reagent for supplying phosphorus ions.

1 . A method of forming a NiP nonmagnetic film by electrolytic plating, 
 wherein said electrolytic plating is performed in NiP plating solution including:    a reagent for supplying nickel ions;    a reagent for supplying phosphorus ions; and    a reagent including carboxyl groups.    
   
   
       2 . The method according to  claim 1 , 
 wherein the reagent including carboxyl groups is sodium citrate.    
   
   
       3 . The method according to  claim 1 , 
 wherein rate of depositing said NiP film is 0.01-0.04 μm/min.    
   
   
       4 . The method according to  claim 3 , 
 wherein current density of a plating current is 5 mA/cm 2  or more.    
   
   
       5 . The method according to  claim 1 , 
 wherein a pH value of the NiP plating solution is 4-8.    
   
   
       6 . A method of manufacturing a magnetic head including: a plurality of magnetic films, which are formed as magnetic poles or magnetic shielding layers; and a NiP nonmagnetic film, which are formed as a separation layer separating the magnetic films or a protection layer covering a surface of the magnetic film by electrolytic plating, 
 wherein said electrolytic plating is performed in NiP plating solution including:    a reagent for supplying nickel ions;    a reagent for supplying phosphorus ions; and    a reagent including carboxyl groups.    
   
   
       7 . The method according to  claim 6 , 
 wherein the reagent including carboxyl groups is sodium citrate.    
   
   
       8 . The method according to  claim 6 , 
 wherein rate of depositing the NiP nonmagnetic film is 0.01-0.04 μm/Min.    
   
   
       9 . The method according to  claim 8 , 
 wherein current density of a plating current is 5 mA/cm 2  or more.    
   
   
       10 . The method according to  claim 6 , 
 wherein a pH value of the NiP plating solution is 4-8.    
   
   
       11 . The method according to  claim 6 , 
 wherein the NiP nonmagnetic film is formed between a lower magnetic pole and an upper magnetic pole, which are made of magnetic films, as a write-gap layer.