Composite Thin-Film Magnetic Head, Magnetic Head Assembly And Magnetic Disk Drive Apparatus

A composite thin-film magnetic head comprising:

• a substrate;
• a first insulation layer laminated on said substrate;
• a magnetoresistive effect read head element formed on said first insulation layer and provided with a lower shield layer, an upper shield layer and a magnetoresistive effect layer in which a sense current flows in a direction perpendicular to a surface of said magnetoresistive effect layer through said upper shield layer and said lower shield layer;
• a second insulation layer laminated on said magnetoresistive effect read head element;
• an inductive write head element formed on said second insulation layer and provided with a lower magnetic pole layer, a recording gap layer, an upper magnetic pole layer whose end portion is opposed to an end portion of said lower magnetic pole layer through said recording gap layer and a write coil;
• and
• a nonmagnetic conductive layer electrically conducted with said lower magnetic pole layer and opposed to said upper shield layer in order to increase substantially countered area between said upper shield layer and said lower magnetic pole layer,
• a parasitic capacitance generated between said substrate and said lower shield layer being substantially equal to a parasitic capacitance generated between said upper shield layer and said lower magnetic pole layer, and an electrical resistance between said substrate and said lower magnetic pole layer being 100Ω or less.

A magnetic head assembly including a composite thin-film magnetic head and a support member for supporting said composite thin-film magnetic head, said composite thin-film magnetic head comprising:

• a substrate;
• a first insulation layer laminated on said substrate;
• a magnetoresistive effect read head element formed on said first insulation layer and provided with a lower shield layer, an upper shield layer and a magnetoresistive effect layer in which a sense current flows in a direction perpendicular to a surface of said magnetoresistive effect layer through said upper shield layer and said lower shield layer;
• a second insulation layer laminated on said magnetoresistive effect read head element;
• an inductive write head element formed on said second insulation layer and provided with a lower magnetic pole layer, a recording gap layer, an upper magnetic pole layer whose end portion is opposed to an end portion of said lower magnetic pole layer through said recording gap layer and a write coil;
• and
• a nonmagnetic conductive layer electrically conducted with said lower magnetic pole layer and opposed to said upper shield layer in order to increase substantially countered area between said upper shield layer and said lower magnetic pole layer.

A magnetic disk drive apparatus including at least one magnetic disk, at least one composite thin-film magnetic head and at least one support member for supporting said at least one composite thin-film magnetic head, each composite thin-film magnetic head comprising:

• a substrate;
• a first insulation layer laminated on said substrate;
• a magnetoresistive effect read head element formed on said first insulation layer and provided with a lower shield layer, an upper shield layer and a magnetoresistive effect layer in which a sense current flows in a direction perpendicular to a surface of said magnetoresistive effect layer through said upper shield layer and said lower shield layer;
• a second insulation layer laminated on said magnetoresistive effect read head element;
• an inductive write head element formed on said second insulation layer and provided with a lower magnetic pole layer, a recording gap layer, an upper magnetic pole layer whose end portion is opposed to an end portion of said lower magnetic pole layer through said recording gap layer and a write coil;
• and
• a nonmagnetic conductive layer electrically conducted with said lower magnetic pole layer and opposed to said upper shield layer in order to increase substantially countered area between said upper shield layer and said lower magnetic pole layer.