Thin-film magnetic head and manufacturing method of the head

Abstract

A thin-film magnetic head includes a thin-film magnetic circuit that contains a coil conductor with at least one surface. The coil conductor includes a plurality of grooves for reducing electrical resistance of the coil conductor due to skin effect. The grooves are formed on the at least one surface of the coil conductor to run along axis of the coil conductor.

What is claimed is:  
     
         1 . A thin-film magnetic head including a thin-film magnetic circuit which contains a coil conductor with at least one surface, said coil conductor comprising a plurality of grooves for reducing electrical resistance of said coil conductor due to skin effect, said grooves being formed on the at least one surface of said coil conductor to run along axis of said coil conductor.  
     
     
         2 . The thin-film magnetic head as claimed in    claim 1   , wherein said coil conductor has side faces, and wherein said plurality of grooves for reducing electrical resistance due to the skin effect are formed on said side faces.  
     
     
         3 . The thin-film magnetic head as claimed in    claim 1   , wherein said plurality of grooves for reducing electrical resistance due to the skin effect are many grooves with many projections and depressions.  
     
     
         4 . The thin-film magnetic head as claimed in    claim 1   , wherein said plurality of grooves for reducing electrical resistance due to the skin effect have pitches of about 0.05-0.2 μm.  
     
     
         5 . The thin-film magnetic head as claimed in    claim 1   , wherein said plurality of grooves for reducing electrical resistance due to the skin effect have a depth of about 0.01-0.1 μm.  
     
     
         6 . A manufacturing method of a thin-film magnetic head including a thin-film magnetic circuit which contains a coil conductor, said method comprising the steps of: 
 forming a resist layer;    exposing said formed resist layer by applying a monochromatic light via a mask with a predetermined pattern;    developing the exposed resist layer without performing a post exposure baking process; and    plating said coil conductor by using said developed resist layer.    
     
     
         7 . The manufacturing method as claimed in    claim 6   , wherein said exposing step includes a step of exposing said formed resist layer by applying a monochromatic light via a mask with a predetermined pattern to make resist trenches with a plurality of grooves on inner walls of said resist trenches.  
     
     
         8 . The manufacturing method as claimed in    claim 7   , wherein said plurality of grooves are many grooves with many projections and depressions  
     
     
         9 . The manufacturing method as claimed in    claim 7   , wherein said plurality of grooves have pitches of about 0.05-0.2 μm.  
     
     
         10 . The manufacturing method as claimed in    claim 7   , wherein said plurality of grooves have a depth of about 0.01-0.1 μm.  
     
     
         11 . A manufacturing method of a thin-film magnetic head, said method including the steps of: 
 forming a lower magnetic pole layer;    depositing a magnetic gap layer on said lower magnetic pole layer;    forming a coil conductor with at least one surface above said magnetic gap layer; and    forming an upper magnetic pole layer above said magnetic gap layer,    said coil conductor forming step comprising the steps of: 
 forming a low resistance layer on said magnetic gap layer;  
 forming a resist layer on said low resistance layer;  
 exposing said formed resist layer by applying a monochromatic light via a mask with a predetermined pattern;  
 developing the exposed resist layer without performing a post exposure baking process;  
 plating said coil conductor by using said developed resist layer; and  
 thereafter, removing said resist layer.  
   
     
     
         12 . The manufacturing method as claimed in    claim 11   , wherein said exposing step includes a step of exposing said formed resist layer by applying a monochromatic light via a mask with a predetermined pattern to make resist trenches with a plurality of grooves on inner walls of said resist trenches.  
     
     
         13 . The manufacturing method as claimed in    claim 12   , wherein said plurality of grooves are many grooves with many projections and depressions  
     
     
         14 . The manufacturing method as claimed in    claim 12   , wherein said plurality of grooves have pitches of about 0.05-0.2 μm.  
     
     
         15 . The manufacturing method as claimed in    claim 12   , wherein said plurality of grooves have a depth of about 0.01-0.1 μm.