Yoke type reproducing magnetic head, method for fabricating same, and magnetic disk unit

Abstract

In a yoke type reproducing magnetic head, a magnetoresistance effect film can be arranged in the vicinity of a medium facing surface, so that sensitivity is improved. The yoke type reproducing magnetic head comprises: a pair of magnetic yokes which face each other via a magnetic gap, at least one of the pair of magnetic yokes extending from a medium facing surface to a position retracted from the medium facing surface; a magnetoresistance effect film which has a curved portion protruding toward the medium facing surface in the magnetic gap and which is magnetically connected to the magnetic yokes; and an electrode which is electrically connected to the magnetoresistance effect film.

What is claimed is:  
     
         1 . A yoke type reproducing magnetic head comprising: 
 a pair of magnetic yokes facing each other via a magnetic gap, at least one of said pair of magnetic yokes extending from a medium facing surface to a position backed from said medium facing surface;    a magnetoresistance effect film having a curved portion protruding toward said medium facing surface in said magnetic gap and being magnetically connected to said magnetic yokes; and    an electrode electrically connected to said magnetoresistance effect film.    
     
     
         2 . A yoke type reproducing magnetic head as set forth in  claim 1 , wherein said magnetoresistance effect film is electrically connected to said pair of magnetic yokes.  
     
     
         3 . A yoke type reproducing magnetic head as set forth in  claim 1 , wherein a part of said electrode is electrically connected to the opposite surface of said magnetoresistance effect film to the protruding surface thereof.  
     
     
         4 . A yoke type reproducing magnetic head as set forth in  claim 1 , wherein said electrode comprises first and second electrode portions, and end portions of said first and second electrode portions are electrically connected to end portions of said magnetoresistance effect film in said magnetic gap, respectively.  
     
     
         5 . A yoke type reproducing magnetic head as set forth in  claim 1 , wherein said magnetoresistance effect film comprises: a magnetization free layer in which the direction of magnetization moves in response to the direction of a signal magnetic field; a non-magnetic layer stacked on said magnetization free layer; and a magnetization fixed layer which is staked on said non-magnetic layer and in which the direction of magnetization does not substantially vary even in said signal magnetic field, said magnetization free layer being formed on the side of said medium facing surface.  
     
     
         6 . A yoke type reproducing magnetic head as set forth in  claim 1 , wherein said magnetic yoke is electrically connected to said magnetoresistance effect film.  
     
     
         7 . A yoke type reproducing magnetic head comprising: 
 a magnetic yoke having a magnetic gap; and    a magnetoresistance effect film which comprises a magnetization free layer in which the direction of magnetization moves in response to the direction of a signal magnetic field, a non-magnetic layer stacked on said magnetization free layer, and a magnetization fixed layer which is staked on said non-magnetic layer and in which the direction of magnetization does not substantially vary even in said signal magnetic field, the size of the film surface of a part of said magnetization fixed layer being formed so as to be smaller than the size of the film surface of said magnetization free layer,    a part of said magnetic yoke including said magnetic gap on the opposite surface of same magnetic yoke to a medium facing surface being electrically connected to the top face of said magnetization fixed layer of said magnetoresistance effect film.    
     
     
         8 . A yoke type reproducing magnetic head as set forth in  claim 7 , wherein said magnetic yoke is electrically insulated from said magnetoresistance effect film by an insulating film, except for the top face of said magnetization fixed layer.  
     
     
         9 . A yoke type reproducing magnetic head as set forth in  claim 8 , wherein the film surface of said insulating film on the side of said magnetic yoke and the top face of said magnetization fixed layer substantially form the same flat surface.  
     
     
         10 . A yoke type reproducing magnetic head as set forth in  claim 8 , wherein the thickness of said insulating film is substantially equal to the height from the film surface of said magnetization free layer to the film surface of said magnetization fixed layer in the vicinity of said magnetoresistance effect film, and increases as leaving said magnetization fixed layer.  
     
     
         11 . A method for fabricating a yoke type reproducing magnetic head, said method comprising: 
 forming a pair of magnetic yokes facing each other via a magnetic gap;    filling said magnetic gap with a non-magnetic film having a different etching rate from that of said magnetic yokes;    forming a portion having a difference in level, in said magnetic gap portion by utilizing a difference in etching rate; and    filling said portion having the difference in level, with a magnetoresistance effect film.    
     
     
         12 . A method for fabricating a yoke type reproducing magnetic head as set forth in  claim 11 , which further comprises leaving a portion having a difference in level when filling with said magnetoresistance effect film, and forming a part or all of an electrode extracting lead in said portion having the difference in level.  
     
     
         13 . A method for fabricating a yoke type reproducing magnetic head, said method comprising: 
 forming a magnetic yoke;    forming a portion having a difference in level, between the opposite surface of said magnetic yoke to a medium facing surface and the opposite surface of said magnetic gap to said medium facing surface; and    filling said portion having the difference in level, with a magnetoresistance effect film.    
     
     
         14 . A method for fabricating a yoke type reproducing magnetic head as set forth in  claim 13 , which further comprises leaving a portion having a difference in level when filling with said magnetoresistance effect film, and forming a part or all of an electrode extracting lead in said portion having the difference in level.  
     
     
         15 . A method for fabricating a yoke type reproducing magnetic head, said method comprising: 
 forming an electrode having a protruding portion;    forming a side wall of an insulating film on the side of said protruding portion;    forming a magnetoresistance effect film so as to cover said protruding portion and said side wall; and    forming a magnetic yoke having a magnetic gap on said protruding portion.    
     
     
         16 . A method for fabricating a yoke type reproducing magnetic head, said method comprising: 
 forming a magnetoresistance effect film comprising a magnetization free layer in which the direction of magnetization moves in response to the direction  6 f a signal magnetic field, a non-magnetic layer stacked on said magnetization free layer, and a magnetization fixed layer which is staked on said non-magnetic layer and in which the direction of magnetization does not substantially vary even in said signal magnetic field, the size of the film surface of a part of said magnetization fixed layer being smaller than the size of the film surface of said magnetization free layer;    forming an insulating film having a contact hole, the bottom face of which is substantially the whole top face of said magnetization fixed layer, on said magnetoresistance effect film; and    forming a magnetic yoke having a magnetic gap in said contact hole and being electrically connected to the top face of said magnetization fixed layer.    
     
     
         17 . A method for fabricating a yoke type reproducing magnetic head as set forth in  claim 16 , wherein said contact hole is formed so as to be self-aligned with said pinned layer.  
     
     
         18 . A magnetic disk unit using a yoke type reproducing magnetic head according to  claim 1 , as a reproducing magnetic head.  
     
     
         19 . A magnetic disk unit using a yoke type reproducing magnetic head according to  claim 7 , as a reproducing magnetic head.