Method of making a magnetoresistive head with integrated bias and magnetic shield layer
AssigneeMinnesota Mining and Manufacturing Company
InventorsTheodore A. Schwarz, Peter G. Bischoff, Chak M. Leung, Johnny C. Chen, Pradeep Thayamballi
Life of this patent
Estimating the term…
Abstract
A thin-film magnetoresistive playback head having films providing magnetic shielding and magnetic bias. At least one of the magnetic shield layers is also conductive so that the functions of shielding and biasing are combined. Preferably, both shield layers are conductive. A multiple element channel head is disclosed in which the magnetic/conductive layers extend in series from one transducer section to the next, allowing a single bias current to bias all of the sections.
Claims7
A method for making a thin-film magnetoresistive recording head comprising the steps of
- providing a substrate having a non-conductive, non-magnetic surface,
- depositing on said substrate surface a thin film layer of an electrically conducting, low coercive force and high permeability material to form a first shield layer configured with means for enabling current flow through said layer to provide a magnetic bias field,
- depositing over said first shield layer a first thin film insulator layer,
- depositing over said first thin film insulator layer a thin film layer of a low coercive force, high permeability magnetoresistive material,
- depositing over said layer of magnetoresistive material a thin film of a conductive material, configured to provide a pair of sense leads for the film of magnetoresistive material, the distance between the leads defining the length of the transducer formed by the magnetoresistive layer, and extending away from a first edge of the magnetoresistive layer to provide contact pads facilitating external connections,
- depositing over said thin conductive film a second thin film insulator layer,
- depositing over said second thin film layer a second thin film layer of an electrically conducting, low coercive force, high permeability material to form a second shield layer configured with means for enabling current flow therethrough to contribute to said bias field,
- wherein the thickness of each of the magnetically permeable layers is not less than three times the distance between opposing faces of the magnetically permeable layers, and
- forming a surface along said edge which is common to all said layers, the distance from said surface to the opposite edge of the magnetoresistive film defining the throat height of said transducer.
Dependencies are inferred from the claim text.