# US 11,308,981 B2 · Microwave assisted magnetic recording head slider and lapping method thereof

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- Number: US 11,308,981 B2
- Document ID: US11308981B2
- Status: Granted
- Kind: B2
- Application number: 17/341,553
- Filed: 2021-06-08
- Published: 2022-01-06
- Granted: 2022-04-19
- Earliest claimed: 2020-07-03
- Assignees: SAE Magnetics (H.K.) Ltd.
- Applicants: SAE Magnetics (H.K.) Ltd.
- Inventors: Shi Xiong Chen; Bin Qi; Wen Rong Guo; Peng Liu
- Web page: https://patentgrep.com/patent/US11308981B2

## CPC

- G11B 5/1871: {Shaping or contouring of the transducing or guiding surface}
- G11B 5/255: comprising means for protection against wear {(in thin film structures G11B5/3106)}
- G11B 2005/0024: {Microwave assisted recording}
- 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 lapping method of a MAMR head slider includes a first lapping process: controlling the lapping plate to spin at a first speed, and controlling the MAMR head slider to move at a first moving speed, and applying a first force to the MAMR head slider; and a second lapping process: controlling the lapping plate to spin at a second speed that is lower than the first speed, and controlling the MAMR head slider to move at a second moving speed that is lower than the first moving speed, and applying a second force that is lower than the first force to the MAMR head slider; and the second lapping process includes a final lapping process section, and the second force in the final lapping process being zero. In such a way, lapping marks on the ABS are reduced to improve the roughness and the reliability.

## Claims

### Claim 1

A lapping method of a microwave assisted magnetic recording (MAMR) head slider, adapted for polishing a predetermined surface of the MAMR head slider by a lapping plate with a lapping surface to form a MAMR head having a spin torque oscillator (STO) on the predetermined surface, and the lapping method comprising:
a first lapping process: controlling the lapping plate to spin at a first speed, and controlling the MAMR head slider to move at a first moving speed, and applying a first force to the MAMR head slider so as to polish the predetermined surface; and
a second lapping process: controlling the lapping plate to spin at a second speed that is lower than the first speed, and controlling the MAMR head slider to move at a second moving speed that is lower than the first moving speed, and applying a second force that is lower than the first force to the MAMR head slider so as to polish the predetermined surface;
and the second lapping process comprising a final lapping process section, and the second force in the final lapping process being zero.

### Claim 2 (depends on 1)

The lapping method according to claim 1, wherein in the second lapping process, the second speed of the lapping plate is in a range of 0.5-0.2 rpm.

### Claim 3 (depends on 1)

The lapping method according to claim 1, wherein in the second lapping process except for the final lapping process section, the second force applied to the MAMR head slider is larger than zero and smaller than 0.6 kgf.

### Claim 4 (depends on 1)

The lapping method according to claim 1, wherein in the second lapping process, the second moving speed of the MAMR head slider is in a range of 0.8-0.25 mm/s.

### Claim 5 (depends on 1)

The lapping method according to claim 1, wherein in the first and second processes, the MAMR head slider is configured to make a reciprocating linear movement along a radial direction of the lapping plate.

### Claim 6 (depends on 1)

The lapping method according to claim 1, wherein in the first and second processes, the MAMR head slider is configured to apply the first and the second forces in a direction perpendicular to a surface of the lapping surface.

### Claim 7 (depends on 1)

The lapping method according to claim 1, wherein the second lapping process comprises multiple sub-lapping process sections and the final lapping process section, the second speed, the second force and the second moving speed in a latter sub-lapping process section is smaller than or equal to that in a previous sub-lapping process section.

### Claim 8 (depends on 1)

A microwave assisted magnetic recording (MAMR) head slider obtained according to the method in claim 1, comprising a leading edge, a trailing end, an air bearing surface facing a medium, and a MAMR head embedded in the trailing end and having a spin torque oscillator (STO), and the air bearing surface having unidirectional lapping marks.