Read/write head with reduced pole tip protrusion
View Patent ↗A write element for use in a read/write head having an air bearing surface, so as to reduce pole tip protrusion. The write element includes a pole tip region; an insulation layer formed adjacent to the pole tip region; a coil embedded in the insulation layer which contributes to a protrusion force that generates a pole tip protrusion; and a layer of thermally expansive material formed over the insulation layer, and recessed from the air bearing surface, that expands in response to heat absorption, causing a rotational moment of force that counteracts the protrusion force thus reducing the pole tip protrusion.
1. A read/write head for use in a data storage device to reduce pole tip protrusion, comprising:
an air bearing surface;
a pole tip region;
an insulation layer formed adjacent to the pole tip region;
a coil embedded in the insulation layer contributing to a protrusion force that generates a pole tip protrusion; and
a layer of thermally expansive material formed over the insulation layer, and recessed from the air bearing surface, that expands in response to heat absorption, causing a rotational moment of force that counteracts the protrusion force thus reducing the pole tip protrusion.
2. The read/write head of claim 1 , wherein the layer of thermally expansive material is made at least in part of photoresist material.
3. The read/write head of claim 1 , wherein the layer of thermally expansive material has a coefficient of thermal expansion that ranges between approximately 5 ppm/K and 100 ppm/K.
4. The read/write head of claim 1 , further comprising a write element; and
wherein the layer of thermally expansive material is formed over substantially the entire surface of the write element.
5. The read/write head of claim 4 , further comprising a diffuser formed on top of the insulation layer; and
wherein the layer of thermally expansive material is formed over the diffuser.
6. The read/write head of claim 5 , wherein the diffuser is formed over substantially the entire surface of the write element.
7. The read/write head of claim 5 , wherein the write element is comprised of a first pole layer P 1 , a second pole layer P 2 , and a third pole P 3 .
8. The read/write head of claim 1 , further comprising a read element.
9. A write element for use in a read/write head having an air bearing surface to reduce pole tip protrusion, comprising:
a pole tip region;
an insulation layer formed adjacent to the pole tip region;
a coil embedded in the insulation layer contributing to a protrusion force that generates a pole tip protrusion; and
a layer of thermally expansive material formed over the insulation layer, and recessed from the air bearing surface, that expands in response to heat absorption, causing a rotational moment of force that counteracts the protrusion force thus reducing the pole tip protrusion.
10. The write element of claim 9 , wherein the layer of thermally expansive material is made at least in part of photoresist material.
11. The write element of claim 9 , wherein the layer of thermally expansive material has a coefficient of thermal expansion that ranges between approximately 5 ppm/K and 100 ppm/K.
12. The write element of claim 9 , further comprising a diffuser formed on top of the insulation layer; and
wherein the layer of thermally expansive material is formed over the diffuser.
13. The write element of claim 9 , wherein the write element is comprised of a first pole layer P 1 , a second pole layer P 2 , and a third pole P 3 .
14. A disk drive comprising:
a base;
a spindle motor attached to the base;
a disk positioned on the spindle motor;
a head stack assembly coupled to the base and comprising:
an actuator body;
an actuator arm cantilevered from the actuator body; and
a read/write head coupled to the actuator arm, and including:
an air bearing surface;
a pole tip region;
an insulation layer formed adjacent to the pole tip region;
a coil embedded in the insulation layer contributing to a protrusion force that generates a pole tip protrusion; and
a layer of thermally expansive material formed over the insulation layer, and recessed from the air bearing surface, that expands in response to heat absorption, causing a rotational moment of force that counteracts the protrusion force thus reducing the pole tip protrusion.
15. The disk drive of claim 14 , wherein the layer of thermally expansive material is made at least in part of photoresist material.
16. The disk drive of claim 14 , wherein the layer of thermally expansive material has a coefficient of thermal expansion that ranges between approximately 5 ppm/K and 100 ppm/K.
17. The disk drive of claim 14 , further comprising a write element; and
wherein the layer of thermally expansive material is formed over substantially the entire surface of the write element.
18. The disk drive of claim 14 , further comprising a diffuser formed on top of the insulation layer; and
wherein the layer of thermally expansive material is formed over the diffuser.
19. The disk drive of claim 18 , wherein the diffuser is formed over substantially the entire surface of the write element.
20. The disk drive of claim 14 , further comprising a read element.