# US 8,542,456 B2 · Magnetic head having a contact sensor

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- Number: US 8,542,456 B2
- Document ID: US8542456B2
- Status: Granted
- Kind: B2
- Application number: 13/218,150
- Filed: 2011-08-25
- Published: 2013-02-28
- Granted: 2013-09-24
- Earliest claimed: 2011-08-25
- Assignees: TDK Corporation
- Applicants: Takekazu Yamane; Yosuke Antoku; Katsuki Kurihara; Norio Takahashi; Kenzo Makino
- Inventors: Takekazu Yamane; Yosuke Antoku; Katsuki Kurihara; Norio Takahashi; Kenzo Makino
- Web page: https://patentgrep.com/patent/US8542456B2

## CPC

- G11B 5/6076: {Detecting head-disk contact}
- G11B 5/3133: {including layers not usually being a part of the electromagnetic transducer structure and providing additional features, e.g. for improving heat radiation, reduction of power dissipation, adaptations for measurement or indication of gap depth or other properties of the structure (G11B5/3106 takes precedence)}
- G11B 5/3136: {for reducing the pole-tip-protrusion at the head transducing surface, e.g. caused by thermal expansion of dissimilar materials}
- G11B 5/3146: {magnetic layers}
- G11B 5/607: {using thermal means}
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)

## Abstract

A magnetic head includes a medium facing surface that faces a surface of a recording medium, a write head section, a contact sensor that detects contact of the medium facing surface with the surface of the recording medium, and a heat sink adjacent to the contact sensor. The write head section has a magnetic pole that produces a write magnetic field for writing data on the recording medium. The contact sensor and the heat sink have respective end faces located in the medium facing surface. The contact sensor varies in resistance in response to temperature variations, and is to be energized. The heat sink includes an intermediate layer made of a nonmagnetic metal material, and two ferromagnetic layers made of a metal-based magnetic material, the two ferromagnetic layers being disposed with the intermediate layer therebetween, and being antiferromagnetically exchange-coupled to each other via the intermediate layer.

## Claims

### Claim 1

A magnetic head comprising:
a medium facing surface that faces a surface of a recording medium;
a write head section;
a contact sensor that detects contact of the medium facing surface with the surface of the recording medium; and
a heat sink adjacent to the contact sensor, wherein:
the write head section has a magnetic pole that produces a write magnetic field for writing data on the recording medium;
the contact sensor and the heat sink have respective end faces located in the medium facing surface;
the contact sensor varies in resistance in response to temperature variations, and is to be energized; and
the heat sink includes an intermediate layer made of a nonmagnetic metal material, and two ferromagnetic layers made of a metal-based magnetic material, the two ferromagnetic layers being disposed with the intermediate layer therebetween, and being antiferromagnetically exchange-coupled to each other via the intermediate layer.

### Claim 2 (depends on 1)

The magnetic head according to claim 1, further comprising an insulating film interposed between the contact sensor and the heat sink.

### Claim 3 (depends on 2)

The magnetic head according to claim 2, wherein the insulating film has a thickness greater than zero and smaller than 370 nm.

### Claim 4 (depends on 1)

The magnetic head according to claim 1, further comprising a heater that generates heat for causing part of the medium facing surface to protrude.

### Claim 5 (depends on 1)

A head assembly comprising a slider, and a supporter that flexibly supports the slider, wherein the slider includes the magnetic head according to claim 1, and is disposed to face the surface of the recording medium.

### Claim 6 (depends on 1)

A magnetic recording device comprising the magnetic head according to claim 1, the recording medium, and a positioning device that supports the magnetic head and positions the magnetic head with respect to the recording medium.