Shield stabilization for magnetoresistive sensors
AssigneeHitachi Global Storage Technologies Netherlands B.V.
InventorHardayal Singh Gill
Life of this patent
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Abstract
Apparatus and method for providing a magnetic head that includes a magnetoresistive read sensor disposed between first and second magnetic shields. The shields are configured to reduce protrusion of the shields from a polished flat air bearing surface of the magnetic head upon increases in temperature. This configuration for the shields therefore at least reduces differences in thermal expansion of the shields relative to other parts of the magnetic head forming the air bearing surface. These shields according to some embodiments include one or more ferromagnetic layers exchange coupled with an antiferromagnetic layer. Further, in a particular embodiment, all the ferromagnetic layers within each of the shields can have a combined thickness per shield of less than 500 angstroms.
Claims20
A magnetic head, comprising:
- a non-magnetic insulating portion;
- a magnetoresistive read sensor;
- and
- a shield disposed adjacent the magnetoresistive read sensor, wherein the shield comprises a ferromagnetic first layer, an antiferromagnetic second layer, a non-magnetic third layer, wherein the non-magnetic third layer defines an outermost conductive layer of the shield in contact with the non-magnetic insulating portion, and a ferromagnetic fourth layer, wherein
- the ferromagnetic first layer is less than about 500 angstroms and contacts the antiferromagnetic second layer for exchange coupling;
- the ferromagnetic fourth layer contacts the antiferromagnetic second layer for exchange coupling;
- and
- the ferromagnetic first and fourth layers sandwich the antiferromagnetic second layer.
A magnetic head, comprising:
- a non-magnetic insulating portion;
- a magnetoresistive read sensor;
- and
- a shield disposed adjacent the magnetoresistive read sensor, wherein the shield comprises an antiferromagnetic layer and at least one ferromagnetic layer disposed between the magnetoresistive read sensor and a distal boundary of the shield where the shield interfaces the non-magnetic insulating portion;
- wherein the at least one ferromagnetic layer comprises a first ferromagnetic layer that contacts a first side of the antiferromagnetic layer for exchange coupling and a second ferromagnetic layer that contacts a second side opposite the first side of the antiferromagnetic layer for exchange coupling and all layers of the at least one ferromagnetic layer have a combined thickness less than 500 angstroms.
A magnetic head, comprising:
- a magnetic resistive sensor means for reading data from a magnetic storage medium;
- and
- a shield means for magnetically shielding the sensor means, wherein the shield means comprises:
- a non-magnetic conductive means, wherein the non-magnetic conductive means has a thickness between 500 angstroms (Å) and 1000 Å;
- a ferromagnetic means disposed between the magnetic resistive sensor means and the non-magnetic conductive means;
- an antiferromagnetic means for exchange coupling with the ferromagnetic means.
A method of forming a magnetic head, comprising:
- providing a non-magnetic insulating portion;
- depositing a shield on the non-magnetic insulating portion, wherein depositing the shield comprises depositing a ferromagnetic first layer, depositing an antiferromagnetic second layer, depositing a non-magnetic third layer, wherein the non-magnetic third layer defines an outermost layer of the shield in contact with the non-magnetic insulating portion, and depositing a ferromagnetic fourth layer;
- wherein the ferromagnetic first layer is less than about 500 angstroms and contacts the antiferromagnetic second layer for exchange coupling;
- wherein the ferromagnetic fourth layer contacts the antiferromagnetic second layer for exchange coupling;
- and wherein the ferromagnetic first and fourth layers sandwich the antiferromagnetic second layer;
- and
- depositing a magnetoresistive read sensor on the shield.
Dependencies are inferred from the claim text.