TAR temperature sensor having faster response time
TAR enable write heads may use a plasmonic device (e.g., an optical transducer) which uses electromagnetic energy generated from a laser to heat the magnetic media. However, as the temperature of the plasmonic device rises, the likelihood of stressing the material of the device or other materials of the head near the plasmonic device increases. Accordingly, the write head may include a temperature sensor proximate to the plasmonic device. In one embodiment, the resistance of the temperature sensor may change according to the temperature of the plasmonic device. Based on the measured resistance of the temperature sensor, a sensing circuit may adjust the power of the laser, and thus, prevent the stressing of the materials. Moreover, the thermal coupling between the temperature sensor and a heat sink connected to the plasmonic device may be improved by moving elements associated with the sensing circuit closer to a heat sink.
1. A head of a disk drive, comprising:
an optical transducer configured to heat a magnetic media proximate to the head;
a first heat sink configured to transfer heat away from the optical transducer;
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 along an axis that extends between the temperature sensor and the optical transducer, wherein the first distance between the temperature sensor and the optical transducer is between 5 and 150 nm; and
a first lead connected to the temperature sensor, wherein the first lead is configured to conduct a current flowing through the temperature sensor, and wherein the first lead either (i) contacts the first heat sink or (ii) is separated from the first heat sink by a second distance along the axis, wherein the second distance is shorter than the first distance.
2. The head of claim 1 , wherein the first lead is connected to a first end of the temperature sensor, the head further comprising:
a second lead connected to a second end of the temperature sensor opposite of the first end, wherein the current flows through the second lead.
3. The head of claim 2 , wherein the first lead contacts the first heat sink, and wherein the second lead does not contact a second heat sink located opposite of a side of the optical transducer that faces the first heat sink.
4. The head of claim 2 , further comprising connective elements configured to couple the first and second leads to a sensing circuit that measures a resistance of the temperature sensor and adjusts the temperature of the optical transducer based on the measured resistance.
5. The head of claim 1 , wherein the first lead is separated from the first heat sink by the second distance along the axis, wherein an insulative material is between the first heat sink and the first lead.
6. The head of claim 1 , wherein the first lead comprises a different material from a material of the temperature sensor, wherein the electrical resistance of the material of the first lead changes less based on temperature than a material of the temperature sensor.
7. The head of claim 1 , wherein the temperature sensor comprises at least one of Ta, Pt, Au, Rh, NiFe, and combinations thereof and wherein the first lead comprises at least one of Ru, Cu, Ta, Cr and combinations thereof.
8. A method, comprising:
transmitting optical energy from a laser to an optical transducer located in a head of a disk drive;
measuring an electrical resistance of a temperature sensor thermally coupled to the optical transducer using a first lead connected to the temperature sensor, wherein the electrical resistance correlates to a temperature of the sensor, wherein the temperature sensor and the optical transducer are spaced apart by a first distance along an axis that extends between the temperature sensor and the optical transducer, wherein first distance is between 5 and 150 nm, and wherein the first lead either (i) contacts a first heat sink that transfers heat away from the optical transducer or (ii) is separated from the first heat sink by a second distance along the axis, wherein the second distance is shorter than the first distance; and
adjusting the optical energy transmitted by the laser based on the measured electrical resistance.
9. The method of claim 8 , wherein the first lead is thermally coupled to the first heat sink such that heat emitted from the optical transducer flows through the first heat sink and first lead to the temperature sensor, thereby changing the electrical resistance of the temperature sensor.
10. The method of claim 8 , wherein the first lead is connected to a first end of the temperature sensor, the head comprising:
a second lead connected to a second end of the temperature sensor opposite of the first end, wherein measuring the electrical resistance comprises generating a current through the first and second leads and the temperature sensor.
11. The method of claim 10 , wherein the first lead contacts the first heat sink, and wherein the second lead does not contact a second heat sink located opposite of a side of the optical transducer facing the first heat sink.
12. The method of claim 10 , wherein the head comprises connective elements configured to couple the first and second leads to a sensing circuit that measures the electrical resistance of the temperature sensor.