Bolometer and contact sensor arrangement for a heat-assisted magnetic recording device

Patent metadata

Field	Value
Publication number	US-9972350-B1
Application number	US-201715678409-A
Country	US
Kind code	B1
Filing date	Aug 16, 2017
Priority date	Oct 31, 2016
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

A slider of a heat-assisted magnetic recording head comprises an air bearing surface and an optical waveguide configured to receive light from a laser source. The slider comprises a plurality of electrical bond pads including a first bond pad and a second bond pad. A first resistive sensor is configured to sense for spacing changes and contact between the slider and a magnetic recording medium at or near a first close point of the slider. A second resistive sensor is configured to sense for spacing changes and contact between the slider and the medium at or near a second close point of the slider. A bolometer is situated at a location within the slider that receives at least some of the light communicated along the optical waveguide. The first resistive sensor, the second resistive sensor, and the bolometer are coupled together and between the first and second bond pads.

First claim

What is claimed is:

1. An apparatus, comprising:
a slider of a heat-assisted magnetic recording head comprising an air bearing surface and an optical waveguide configured to receive light from a laser source, the slider comprising a plurality of electrical bond pads including a first bond pad and a second bond pad;
a first resistive sensor configured to sense for spacing changes and contact between the slider and a magnetic recording medium at or near a first close point of the slider;
a second resistive sensor configured to sense for spacing changes and contact between the slider and the medium at or near a second close point of the slider; and
a bolometer situated at a location within the slider that receives at least some of the light communicated along the optical waveguide;
wherein the first resistive sensor, the second resistive sensor, and the bolometer are coupled together and between the first and second bond pads.

2. The apparatus of claim 1 , wherein the first resistive sensor, the second resistive sensor, and the bolometer are coupled together and to only the first and second bond pads of the plurality of electrical bond pads.

3. The apparatus of claim 1 , wherein the first resistive sensor, the second resistive sensor, and the bolometer are coupled in series between the first and second bond pads.

4. The apparatus of claim 1 , wherein:
the first resistive sensor is coupled in parallel with the second resistive sensor; and
the parallel-connected first and second resistive sensors are coupled in series with the bolometer.

5. The apparatus of claim 1 , wherein:
the first resistive sensor is coupled in series with the second resistive sensor; and
the series-connected first and second resistive sensors are coupled in parallel with the bolometer.

6. The apparatus of claim 1 , wherein the first resistive sensor, the second resistive sensor, and the bolometer are coupled in parallel between the first and second bond pads.

7. The apparatus of claim 1 , wherein:
the bolometer is coupled to a reference thermal sensor;
the bolometer is configured to produce a signal in response to a change in an ambient temperature and a change in output optical power of the laser source; and
the reference sensor is configured to produce a signal in response to the change in the ambient temperature but not the change in output optical power of the laser source.

8. The apparatus of claim 7 , wherein signals produced by the bolometer and the reference sensor in response to the ambient temperature change are of substantially equal magnitude but of opposite polarity.

9. The apparatus of claim 7 , wherein the bolometer and the reference thermal sensor are situated on the same isotherm within the slider.

10. The apparatus of claim 1 , further comprising:
a reference thermal sensor situated at a location within the slider unexposed to the light communicated along the optical waveguide; and
the first resistive sensor, second resistive sensor, bolometer, and reference thermal sensor are coupled in series.

11. The apparatus of claim 1 , wherein:
the first resistive sensor is coupled in parallel with the second resistive sensor;
the bolometer is coupled in parallel with a reference thermal sensor situated at a location within the slider unexposed to the light communicated along the optical waveguide; and
the parallel-connected first and second resistive sensors are coupled in series with the parallel-connected bolometer and reference thermal sensor.

12. The apparatus of claim 1 , wherein:
the first resistive sensor is coupled in parallel with the second resistive sensor;
the bolometer is coupled in series with a reference thermal sensor situated at a location within the slider unexposed to the light communicated along the optical waveguide; and
the parallel-connected first and second resistive sensors are coupled in series with the bolometer and the reference thermal sensor.

13. The apparatus of claim 1 , wherein:
the first resistive sensor is coupled in series with the second resistive sensor;
the bolometer is coupled in parallel with a reference thermal sensor situated at a location within the slider unexposed to the light communicated along the optical waveguide; and
the series-connected first and second resistive sensors are coupled in series with the parallel-connected bolometer and reference thermal sensor.

14. The apparatus of claim 1 , wherein:
the first resistive sensor is situated at or near a writer of the slider; and
the second resistive sensor is situated at or near a reader of the slider.

15. An apparatus, comprising:
a slider of a heat-assisted magnetic recording head comprising an air bearing surface and an optical waveguide configured to receive light from a laser source, the slider comprising a plurality of electrical bond pads including a first bond pad and a second bond pad;
a first resistive sensor configured to sense for spacing changes and contact between the slider and a magnetic recording medium at or near a first close point of the slider;
a second resistive sensor configured to sense for spacing changes and contact between the slider and the medium at or near a second close point of the slider;
a bolometer situated at a location within the slider that receives at least some of the light communicated along the waveguide;
a reference thermal sensor coupled to the bolometer, the reference thermal sensor situated at a location within the slider unexposed to the light communicated along the optical waveguide;
wherein signals produced by the bolometer and the reference sensor in response to an ambient temperature change are of substantially equal magnitude but of opposite polarity; and
wherein the first resistive sensor, the second resistive sensor, bolometer, and reference thermal sensor are coupled together and between the first and second bond pads.

16. The apparatus of claim 15 , wherein the bolometer and the reference thermal sensor are situated on the same isotherm within the slider.

17. The apparatus of claim 15 , further comprising:
a reference thermal sensor situated at a location within the slider unexposed to the light communicated along the optical waveguide; and
the first resistive sensor, second resistive sensor, bolometer, and reference thermal sensor are coupled in series.

18. The apparatus of claim 15 , wherein:
the first resistive sensor is coupled in parallel with the second resistive sensor;
the bolometer is coupled in parallel with a reference thermal sensor situated at a location within the slider unexposed to the light communicated along the optical waveguide; and
the parallel-connected first and second resistive sensors are coupled in series with the parallel-connected bolometer and reference thermal sensor.

19. The apparatus of claim 15 , wherein:
the first resistive sensor is coupled in parallel with the second resistive sensor;
the bolometer is coupled in series with a reference thermal sensor situated at a location within the slider unexposed to the light communicated along the optical waveguide; and
the parallel-connected first and second resistive sensors are coupled in series with the bolometer and the reference thermal sensor.

20. The apparatus of claim 15 , wherein:
the first resistive sensor is coupled in series with the second resistive sensor;
the bolometer is coupled in parallel with a reference thermal sensor situated at a location within the slider unexposed to the light communicated along the optical waveguide; and

Assignees

• Seagate Technology Llc

Inventors

• Macken Declan
• Klarqvist Jon Karsten

Classifications

• G11B5/6088

  Optical waveguide in or on flying head · CPC title

• G11B5/6005 Primary

  Specially adapted for spacing from a rotating disc using a fluid cushion · CPC title

• G11B5/314 Primary

  where the layers are extra layers normally not provided in the transducing structure, e.g. optical layers (G11B5/3196 takes precedence) · CPC title

• G11B2005/0021

  Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal · CPC title

• G11B5/4866

  the arm comprising an optical waveguide, e.g. for thermally-assisted recording · CPC title