Thin film magnetic head having magnetic layers of different thickness and manufacturing method therefor

Abstract

A thin film magnetic head for performing recording and readout operations to a magnetic recording medium and a method of manufacturing the head. The magnetic head .[.comprises.]. .Iadd.includes .Iaddend.a substrate, a first magnetic layer formed on the substrate, a conductor coil on the first layer and a second magnetic layer formed on the conductor coil and the first magnetic layer. The second magnetic layer is imparted with a greater thickness than the first magnetic layer to thereby strengthen the magnetic field for recording and reducing the peak shift making appearance in readout operation due to interference between successively read-out waveforms. The thin film magnetic head exhibits an improved reproduction characteristic which permits reproduction with high fidelity the magnetized locations recorded on the medium with high recording density which assures an improved recording characteristic. .Iadd.By controlling the thickness of the second magnetic layer at an inclined portion thereof, magnetic saturation thereat is substantially prevented. .Iaddend.

What is claimed: 
     
       1. A thin film magnetic head for performing recording and reading operations to a magnetic recording medium, comprising a substrate, a substantially planar first magnetic layer formed on said substrate and having one end facing toward said recording medium, a conductor coil formed above said first magnetic layer, and a second magnetic layer formed over said conductor coil and said first magnetic layer, said second magnetic layer being spaced from said first magnetic layer to define a magnetic gap at one end facing toward said recording medium and being magnetically shorted to said first magnetic layer at an other end opposite to said one end, said second magnetic layer having a first side portion facing toward said recording medium and a second side portion opposite to said first side portion, both of said first and second side portions being constituted by inclined portions, and said second magnetic layer at least at said one end positioned in opposition to said first magnetic layer with the magnetic gap being interposed therebetween being 1.2 to 1.4 times as thick as said first magnetic layer. 
     
     
       2. A thin film magnetic head according to claim 1, wherein said inclined portions of said second magnetic layer have a substantially same thickness as that of said first magnetic layer. 
     
     
       3. A method of manufacturing a thin film magnetic head for performing recording and reading operations to a magnetic recording medium, comprising the steps of forming through thin film technique a substantially planar first magnetic layer on a substrate so as to have one end facing toward said recording medium, a conductor coil on said first magnetic layer, and a second magnetic layer on said conductor coil and said first magnetic layer, said second magnetic layer being spaced from said first magnetic layer so as to define a magnetic gap at said one end facing toward said recording medium and being magnetically shorted to said first magnetic layer at an other end opposite to said one end, said second magnetic layer having inclined portions at a side facing toward said recording medium and at the opposite side at which said second magnetic layer is magnetically shorted to said first magnetic layer, respectively, and said second magnetic layer at least at said one end positioned in opposition to said first magnetic layer with the magnetic gap being interposed therebetween being 1.2 to 1.4 time as thick as said first magnetic layer. 
     
     
       4. A method of manufacturing a thin film magnetic head according to claim 3, wherein said inclined portions of said second magnetic layer have a substantially same thickness as that of said first magnetic layer. 
     
     
       5. A thin film magnetic head for performing recording and reading operations on a magnetic recording medium, comprising: a substrate;   a substantially planar first magnetic layer formed on said substrate;   a transducing gap layer formed on said first magnetic layer;   a conductor coil formed on said transducing gap layer; and   a second magnetic layer formed over said conductor coil with an insulator interposed between said conductor coil and said second magnetic layer so that said second magnetic layer has inclined portions, said second magnetic layer having one end where said transducing-gap layer is sandwiched between said first and second magnetic layers to constitute a transducing gap at said one end, said second magnetic layer having an other end magnetically shorted with said first magnetic layer, and said second magnetic layer having a thickness at said one end of said position of said transducing gap of 1.2 to 1.4 times the thickness of said first magnetic layer.   
     
     
       6. A thin film magnetic head for performing recording and reproducing operations on a magnetic recording medium, comprising: a substrate;   a substantially planar first magnetic layer formed on said substrate;   a transducing gap layer formed on said first magnetic layer;   a conductor coil formed on said transducing gap layer;   a second magnetic layer formed over said conductor coil with an insulator interposed between said second magnetic layer and said conductor coil, said second magnetic layer having one end portion at which said transducing gap layer is interposed between said first and second magnetic layers to constitute a transducing gap at said one end portion, said magnetic layer further including a first inclined portion adjacent to said one end portion and a second inclined portion adjacent to an other end portion of said second magnetic layer at which said second magnetic layer is magnetically shorted with said first magnetic layer, and said second magnetic layer having a thickness at said one end portion of 1.2 to 1.4 times the thickness of said first magnetic layer.   
     
     
       7. A method of manufacturing a thin film magnetic head for performing recording and reading operations on a magnetic recording medium, comprising the steps of: (a) sputtering a magnetic material on a substrate to form a substantially planar first magnetic layer;   (b) providing a first material on said first magnetic layer so as to form a layer constituting a transducing gap;   (c) vapor depositing a conductive material on said transducing gap layer to form a conductor coil;   (d) providing an insulating material on said conductor coil; .Iadd.and .Iaddend.   (e) sputtering a magnetic material so as to form a second magnetic layer having one end deposited on said transducing gap layer so that said transducing gap layer is interposed between said first and second magnetic layers to constitute a transducing gap at said one end, .Iadd.an .Iaddend.other end where said second magnetic layer is deposited on said first magnetic layer so that said second magnetic layer is magnetically shorted with said first magnetic layer, and a part of said second magnetic layer between said one end and said .[.another.]. .Iadd.other .Iaddend.end wherein said second magnetic layer is deposited on a surface of a laminate formed through the steps of (a) to (d) so that said second magnetic layer has inclined portions thereat, said second magnetic layer being formed with a thickness at said one end at the position of said transducing gap of 1.2 to 1.4 times the thickness of said first magnetic layer. .Iadd.   
     
     
       8.  A thin film magnetic head for performing recording and reading operations to a magnetic recording medium, comprising: a substrate;   a first magnetic layer overlaid on said substrate;   a conductor coil overlaid on said first magnetic layer; and   a second magnetic layer overlaid on said first magnetic layer and on said conductor coil, said second magnetic layer being spaced from said first magnetic layer to define a magnetic gap at one end facing toward said magnetic recording medium, said second magnetic layer being magnetically shorted to said first magnetic layer at an other end opposite to said one end, said second magnetic layer having inclined portions at parts thereof overlaying said conductor coil between said one end and said other end, said second magnetic layer having a predetermined thickness at least at said one end positioned in opposition to said magnetic recording medium of about 1.2 to about 1.4 times the thickness of said first magnetic layer. .Iaddend..Iadd.9. A thin film magnetic head for performing recording and reading operation to a magnetic recording medium, comprising:   a substrate;   a first magnetic layer overlaid on said substrate;   a conductor coil overlaid on said first magnetic layer; and   a second magnetic layer overlaid on said first magnetic layer and on said conductor coil, said second magnetic layer being spaced from said first magnetic layer to define a magnetic gap at one end facing toward said magnetic recording medium, said second magnetic layer being magnetically shorted to said first magnetic layer at an other end opposite to said one end, said second magnetic layer having inclined portions at parts thereof overlaying said conductor coil between said one end and said other end, said second magnetic layer at least at said one end positioned in opposition to said magnetic recording medium having a predetermined thickness greater than that of said first magnetic layer opposite thereto, said predetermined greater thickness being determined by a coverage factor representing the relative ratio of film thicknesses between planar portions and said inclined portions of said second magnetic layer. .Iaddend..Iadd.10. A thin film magnetic head for performing recording and reading operations to a magnetic recording medium, comprising:   a substrate;   a first magnetic layer overlaid on said substrate;   a conductor coil overlaid on said first magnetic layer; and   a second magnetic layer overlaid on said first magnetic layer and on said conductor coils;   said second magnetic layer being spaced from said first magnetic layer to define a magnetic gap at one end facing toward said magnetic recording medium, said second magnetic layer being magnetically shorted to said first magnetic layer at an other end opposite to said one end, said second magnetic layer having inclined portions at parts thereof overlaying said conductor coil between said one end and said other end, said second magnetic layer at least at said one end positioned in opposition to said magnetic recording medium having a predetermined greater thickness than that of said first magnetic layer opposite thereto, said predetermined greater thickness being determined in accordance with the angle of said inclined portions thereof. .Iaddend.