Temperature sensor in a thermally assisted magnetic recording head
View Patent ↗A method and apparatus for providing a signal for driving a heating element in a TAR or HAMR enabled disk storage system that includes an optical transducer (or near-field optical source) for further focusing the beamspot of a laser onto a magnetic media, thereby heating the media. The storage system includes a temperature sensor proximate to the near-field transducer which provides a feedback loop to the laser driver to adjust the power of the laser.
1. A head of a disk drive, comprising:
an optical transducer configured to heat a magnetic media proximate to the head by focusing light emitted by a radiation source; and
a temperature sensor configured to thermally couple to the optical transducer, wherein the temperature sensor and the optical transducer are spaced apart by a first distance that is between 5 and 150 nm.
2. The head of claim 1 , wherein the first distance between the temperature sensor and the optical transducer is between 10-100 nm.
3. The head of claim 1 , further comprising:
a read pole configured to read data stored in the magnetic media; and
a write pole configured to store data to the magnetic media, wherein the temperature sensor is between the write pole and the read pole.
4. The head of claim 1 , wherein the temperature sensor is recessed away from an air-bearing surface.
5. The head of claim 1 , further comprising a read pole configured to read data stored in the magnetic media, wherein the temperature sensor is located between the optical transducer and the read pole.
6. The head of claim 5 , further comprising a write pole and a return pole configured to store data in the magnetic media, wherein the optical transducer is located between the write and return poles, and wherein the temperature sensor is located between the optical transducer and the return pole.
7. The head of claim 1 , further comprising at least one wire pad connected to the temperature sensor, wherein the head is configured to couple, via the at least one wire pad, to driver circuitry that controls the light emitted by the radiation source based on the electrical resistance of the temperature sensor.
8. The head of claim 7 , wherein the at least one wire pad comprises a different material from a material of the temperature sensor, wherein the electrical resistance of the material of the at least one wire pad changes less based on temperature than a material of the temperature sensor.
9. The head of claim 7 , wherein the temperature sensor comprises at least one of Ta, Pt, Au, Rh, NiFe, and combinations thereof and wherein the at least one wire pad comprises at least one of Ru, Cu, Ta, Cr and combinations thereof.
10. A method, comprising:
transmitting optical energy from a laser to an optical transducer located in a head of a disk drive, wherein the optical transducer focuses the optical energy onto magnetic media;
measuring the electrical resistance of a temperature sensor that is thermally coupled to the optical transducer, wherein the electrical resistance correlates to a temperature of the sensor, and wherein the temperature sensor and the optical transducer are spaced apart by a first distance that is between 5 and 150 nm; and
adjusting the optical energy transmitted by the laser based on the measured electrical resistance.
11. The method of claim 10 , wherein the temperature sensor is located between 10-100 nm of the optical transducer.
12. The method of claim 10 , further comprising:
a read pole configured to read data stored in the magnetic media; and
a write pole configured to store data to the magnetic media, wherein the temperature sensor is between the write pole and the read pole.
13. The method of claim 10 , wherein the temperature sensor is recessed away from an air-bearing surface.
14. The method of claim 10 , further comprising a read pole configured to read data stored in the magnetic media, wherein the temperature sensor is located between the optical transducer and the read pole.
15. The method of claim 14 , further comprising a write pole and a return pole configured to store data in the magnetic media, wherein the optical transducer is located between the write and return poles, and wherein the temperature sensor is located between the optical transducer and the return pole.
16. The method of claim 10 , further comprising at least one wire pad connected to the temperature sensor.
17. The method of claim 16 , wherein the at least one wire pad comprises a different material from a material of the temperature sensor, wherein the electrical resistance of the material of the at least one wire pad changes less based on temperature than a material of the temperature sensor.
18. The method of claim 16 , wherein the temperature sensor comprises at least one of Ta, Pt, Au, Rh, NiFe, and combinations thereof and wherein the at least one wire pad comprises at least one of Ru, Cu, Ta, Cr and combinations thereof.