# US 8,739,391 B2 · Silver alloy electrical lapping guides (ELGs) for fabrication of disk drive sliders with magnetoresistive sensors

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- Number: US 8,739,391 B2
- Document ID: US8739391B2
- Status: Granted
- Kind: B2
- Application number: 13/238,838
- Filed: 2011-09-21
- Published: 2013-03-21
- Granted: 2014-06-03
- Earliest claimed: 2011-09-21
- Assignees: HGST Netherlands B.V.
- Applicants: Jeffrey R. Childress; David Patrick Druist; John Creighton Read
- Inventors: Jeffrey R. Childress; David Patrick Druist; John Creighton Read
- Web page: https://patentgrep.com/patent/US8739391B2

## CPC

- G11B 5/3166: {Testing or indicating in relation thereto, e.g. before the fabrication is completed}
- G11B 5/3169: {Working or finishing the interfacing surface of heads, e.g. lapping of heads}
- G11B 5/6082: {Design of the air bearing surface}
- Y10T 29/53165: Magnetic memory device
- 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)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

An air-bearing slider used in a magnetic recording disk drive has a surface that supports a magnetoresistive (MR) read head or sensor and an electrical lapping guide (ELG) adjacent to the MR sensor. The ELG is formed of a different material than the MR sensor so as to have both a high electrical resistivity and a substantially higher etch rate. When the ELG and MR sensor are etched simultaneously to form their respective back edges, the ELG will have a sharp well-defined non-tapered wall at the back edge. The ELG has a film thickness close to but generally thinner than that of the MR sensor, and a sheet resistance to generally match the resistance measurement capability of the lapping tool. The preferred material for the ELG is an alloy comprising silver (Ag) and one or more of Sn, Ge and zinc Zn.

## Claims

### Claim 1

An air-bearing slider that supports a read/write head in a magnetic recording disk drive, the slider having a generally planar upper surface and an air-bearing surface (ABS) generally orthogonal to said upper surface, the slider comprising:
a magnetoresistive sensor directly on the upper surface, the sensor being formed of a stack of multiple layers and having a front edge at the ABS and a back edge recessed from said sensor front edge, the sensor back edge having a planar portion generally parallel to the sensor front edge and substantially orthogonal to the upper surface and a tapered portion nonparallel to the sensor front edge and the upper surface and connecting the upper surface to the planar portion of the sensor back edge; and
an electrical lapping guide (ELG) on the upper surface adjacent to the sensor and having a front edge at the ABS and a back edge generally parallel to and recessed from said ELG front edge and substantially orthogonal to the upper surface, the ELG being formed of an alloy comprising Ag and one or more of Sn, Ge and Zn.

### Claim 2 (depends on 1)

The slider of claim 1 wherein said alloy comprises Ag and Sn, wherein Sn is present in an amount greater than or equal to 3 atomic percent and less than or equal to 20 atomic percent.