Thin laminated single pole perpendicular write head
AssigneeHeadway Technologies, Inc.
InventorsKochan Ju, Lijie Guan, Jeiwei Chang, Min Li, Ben Hu
Life of this patent
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Abstract
Single write poles tend to large shape anisotropy which results in a very large remnant field when not actually writing. This has now been eliminated by giving the write pole the form of a three layer laminate in which two ferromagnetic layers are separated by a non-magnetic or antiferromagnetic coupling layer. Strong magnetostatic coupling between the outer layers causes their magnetization directions to automatically be antiparallel to one another, unless overcome by the more powerful write field, leaving the structure with a low net magnetic moment. The thickness of the middle layer must be carefully controlled.
Claims16
A method to manufacture a perpendicular magnetic writer, comprising:
- providing a magnetic yoke having a bottom surface and an exposed top surface, said bottom surface being magnetically connected to a return pole;
- providing a conductive coil that surrounds said yoke;
- depositing a lower layer of ferromagnetic material onto an area that includes said front surface;
- depositing a layer of non-magnetic material on said lower layer;
- depositing an upper ferromagnetic layer on said layer of non-magnetic material whereby there is no exchange coupling between said upper and lower ferromagnetic layers;
- patterning said upper and lower ferromagnetic layers, as well as said non-magnetic layer, to form a laminated write pole that extends from said yoke in the same direction as the return pole and that has a bottom surface that is coplanar with that of said return pole;
- and
- thereby causing said laminated write pole to have a residual flux density that is less than about 0.1 T.
A perpendicular magnetic writer, comprising:
- a magnetic yoke having first and second ends, said second end being magnetically connected to a return pole that extends away from said yoke in a direction;
- a conductive coil that surrounds said yoke;
- a write pole that extends from said yoke's first end in the same direction as the return pole and that has a bottom surface that is coplanar with that of said return pole;
- said write pole being a laminate of upper and lower ferromagnetic layers separated by a layer of non-magnetic material, there being no other layers in said laminate;
- there being no exchange coupling between said upper and lower ferromagnetic layers;
- and
- said laminated write pole having a residual flux density that is less than about 0.1 T.
Dependencies are inferred from the claim text.