Patent ID: 7675716

Claim:
A composite thin-film magnetic head comprising: a substrate; an under layer formed on said substrate; a magnetoresistive effect read head element formed on said under 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, said lower shield layer being electrically insulated from said substrate to induce a first parasitic capacitance between said substrate and said lower shield layer; an inter-shield insulation layer laminated on said magnetoresistive effect read head element; an inductive write head element formed on said inter-shield insulation layer and provided with a first magnetic pole layer, a nonmagnetic layer, a second magnetic pole layer whose end portion is opposed to an end portion of said first magnetic pole layer through said nonmagnetic layer, and a write coil; and an additional shield layer formed between said upper shield layer and said first magnetic pole layer so that said additional shield layer is electrically connected with said first magnetic pole layer but electrically insulated from said upper shield layer to induce a second parasitic capacitance between said additional shield layer and said upper shield layer, the first parasitic capacitance being substantially the same as the second parasitic capacitance, and an electrical resistance between said substrate and said additional shield layer being 100 Ω or less.