Optimization of temperature dependent variations in shield and pole recession/protrusion through use of a composite overcoat layer
AssigneeSeagate Technology LLC
InventorsMoshe Olim, Ladislav R. Pust
Life of this patent
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Abstract
A magnetic head has an air bearing surface, a substrate, a data transducer and a composite overcoat layer. The data transducer is positioned upon the substrate adjacent the air bearing surface. The data transducer includes a plurality of metallic layers. The composite overcoat layer is positioned upon the data transducer on a side of the data transducer opposite the substrate. An effective coefficient of thermal expansion of the composite overcoat layer is substantially equal to a coefficient of thermal expansion of a material forming the substrate.
Claims20
A magnetic data storage and retrieval system comprising:
- a magnetic head having an air bearing surface and a height measured substantially normal to the air bearing surface, the magnetic head having a substrate and a data transducer positioned upon the substrate, the data transducer comprising at least one metallic layer formed of a material having a coefficient of thermal expansion greater than a coefficient of thermal expansion of a material forming the substrate;
- and
- a composite overcoat layer positioned upon the data transducer on a side of the data transducer opposite the substrate, the overcoat layer being a single layer patterned from a first material and a second material such that blocks of the first and second materials alternate along the height of the magnetic head, the first material having a coefficient of thermal expansion substantially equal to or greater than a coefficient of thermal expansion of the material forming the substrate and the second material having a coefficient of thermal expansion less than the coefficient of thermal expansion of the material forming the substrate.
A magnetic head having an air bearing surface and a height measured substantially normal to air bearing surface the magnetic head comprising:
- a substrate;
- a data transducer positioned upon the substrate adjacent the air bearing surface, the data transducer comprising a plurality of metallic layers;
- and
- a composite overcoat layer positioned upon the data transducer on a side of the data transducer opposite the substrate, wherein an effective coefficient of thermal expansion of the composite overcoat layer is substantially equal to a coefficient of thermal expansion of a material forming the substrate, wherein the composite overcoat layer is patterned from blocks of at least two overcoat materials positioned such that the blocks are distributed along the height of the data transducer.
A magnetic head having an air bearing surface and a height measured substantially normal to the air bearing surface the magnetic head comprising:
- a substrate;
- a data transducer positioned upon the substrate adjacent the air bearing surface, the data transducer comprising a plurality of metallic layers;
- and
- a composite overcoat layer positioned upon the data transducer on a side of the data transducer opposite the substrate, the composite overcoat layer comprising a first overcoat material having a coefficient of thermal expansion substantially equal to or greater than a coefficient of thermal expansion of a material forming the substrate and a second overcoat material having a coefficient of thermal expansion less than the coefficient of thermal expansion of the material forming the substrate, the composite overcoat layer being patterned with blocks of the second overcoat material being embedded within the first overcoat material such that the blocks of the second overcoat material are distributed along the height of the data transducer and so that an effective coefficient of thermal expansion of the composite overcoat layer is substantially equal to the coefficient of thermal expansion of the material forming the substrate.
Dependencies are inferred from the claim text.