Perpendicular Magnetic Recording (PMR) Writer with Recessed Leading Shield

Patent metadata

Field	Value
Publication number	US-2022223176-A1
Application number	US-202217708222-A
Country	US
Kind code	A1
Filing date	Mar 30, 2022
Priority date	Dec 4, 2018
Publication date	Jul 14, 2022
Grant date	—

Abstract

A PMR (perpendicular magnetic recording) write head includes a main write pole (MP) that is surrounded by magnetic shields, including laterally disposed side shields (SS), a trailing shield (TS) and a leading shield (LS). The leading shield includes a leading-edge taper (LET) that conformally abuts a tapered side of the write pole. The leading-edge shield and the leading-edge taper can be independently recessed in a proximal direction away from an air bearing surface (ABS) plane so that one or the other of them is recessed and the other remains coplanar with the ABS, or both are recessed by independent amounts. In another configuration the LS is not planar but has a recessed portion in a center track region and two surrounding regions that are coplanar with the ABS plane.

First claim

What is claimed is:

1 . A write head for perpendicular magnetic recording (PMR) comprising:
a main pole, tapered along a leading edge to produce a distal narrowing, having a distal pole tip that terminates in an air bearing surface (ABS) plane; a trailing shield (TS) formed at a trailing edge side of said pole tip, said TS having a distal planar edge that is co-planar with said ABS plane; horizontally disposed side shields (SS) symmetrically formed to each side of said pole tip, said SS having distal planar edges that are co-planar with said ABS plane; a leading shield (LS) layer formed at a leading edge side of said pole tip, wherein said LS layer has a planar distal edge comprising two connected portions, each parallel to said ABS plane, wherein a first portion has a distal edge that is co-planar with said ABS plane or is positioned proximally away therefrom and parallel with said ABS plane and a second portion, formed in said first portion, that is recessed proximally relative to said first portion; a leading edge taper (LET) layer, independent of and separated from said recessed portion of said leading shield (LS) layer, said LET layer being formed adjacent to said leading shield layer and between said recessed portion of said leading shield layer and said pole tip, wherein a tapered trailing edge surface of said leading edge taper (LET) layer is conformally adjacent to said tapered leading edge surface of said main pole and has a planar distal edge that is parallel to said ABS plane and parallel to and positioned independently of said distal edge of said LS layer; wherein either said recessed portion of said LS layer or said planar distal edge of said LET layer is recessed proximally away from said ABS plane or wherein both said recessed planar distal edge of said LS layer and said planar distal edge of said LET layer are recessed proximally away from said ABS plane; whereby a reduction in return magnetic flux to said LET and said recessed portion of said LS occurs at said leading edge of said main pole and a corresponding increase in return magnetic flux occurs at a trailing edge of said main pole.

2 . The write head of claim 1 wherein said LS layer and said LET layer are not coplanar and wherein said LS layer is coplanar with said ABS plane and said LET layer is recessed from said ABS plane by an amount ranging from 50 nm (nanometers) to 1 μm (microns).

3 . The write head of claim 2 wherein said LS layer and said LET layer are not coplanar and wherein said LET layer is coplanar with said ABS plane and said LS layer is recessed from said ABS plane by an amount ranging from 50 nm to 1 μm.

4 . The write head of claim 3 wherein said LS layer has a throat height that is approximately 150 nm and a recess height from said ABS plane that is approximately 600 nm.

5 . A write head for perpendicular magnetic recording (PMR) comprising:
a main pole having a distal pole tip that terminates in an air bearing surface (ABS) plane; a trailing shield (TS) formed at a trailing edge side of said pole tip said TS having a distal planar edge that is co-planar with said ABS plane; horizontally disposed side shields (SS) symmetrically formed to each side of said pole tip, said SS having distal planar edges that are co-planar with said ABS plane; a leading shield (LS) layer formed at a leading edge side of said pole tip wherein said LS layer has a distal edge having a central planar portion that is parallel to said ABS plane but recessed proximally away from said ABS plane and having two symmetrically disposed planar regions on opposite sides of said central region that are co-planar with said ABS plane, wherein said symmetrically disposed regions are continuously connected to said recessed region by means of upwardly tilted portions that make opposite recess tilt angles θ to the ABS plane; wherein a leading-edge taper (LET) layer is formed on said leading shield, wherein said leading edge taper layer is conformally adjacent to a tapered edge of said main pole and has a planar distal edge that is parallel to said ABS plane; wherein at least one of said planar distal edge of said LS layer and said planar distal edge of said LET layer are recessed from said ABS plane.

6 . The write head of claim 5 wherein a cross-track width of said central recessed region of said LS layer-is between approximately 100 nm and 5 μm.

7 . The write head of claim 5 wherein 0 is between 10 deg. and 90 deg.

8 . The write head of claim 5 wherein said planar distal edges of said LS layer and said LET layer are coplanar.

9 . The write head of claim 5 wherein said LS layer and said LET layer are not coplanar and wherein said LS layer is coplanar with said ABS plane and said LET layer is recessed from said ABS plane by an amount ranging from 50 nm to 1 μm.

10 . The write head of claim 5 wherein said LS layer and said LET layer are not coplanar and wherein said LET layer is coplanar with said ABS plane and said LS layer is recessed from said ABS plane by an amount ranging from 50 nm to 1 μm.

11 . The write head of claim 5 wherein said LS layer has a throat height that is approximately 150 nm and a recess height from said ABS plane that is approximately 600 nm.

12 . The write head of claim 5 wherein said SS have a throat height of approximately 600 nm.

13 . The write head of claim 5 wherein said LS layer has a cross-track width of up to approximately 20 μm.

14 . The write head of claim 5 wherein said trailing shield (TS) includes a small layer of high saturation moment material of Bs of approximately 24 kG immediately adjacent to the pole tip whereas the remainder of the TS is formed of low saturation material of Bs between 16 and 19 kG.

15 . The write head of claim 5 wherein the shield material for the LS and LET are independently chosen but have a Bs in a range between 1 kG and 19 kG and is chosen to be lower than that for the SS material.

16 . The write head of claim 5 wherein all shields that are immediately adjacent to said write pole are nevertheless separated from said write pole by gap regions that are filled with dielectric material or non-magnetic metals.

17 . A head gimbal assembly, comprising
the write head of claim 5 , wherein said write head is mounted in a slider; a suspension that elastically supports said slider-mounted PMR write head, wherein said suspension has a flexure to which said slider-mounted PMR write head is joined, a load beam with one end connected to said flexure and a base plate connected to the other end of said load beam.

18 . A magnetic recording apparatus, comprising:
the head gimbal assembly of claim 17 ; a magnetic recording medium positioned opposite to said slider; a spindle motor that rotates and drives said magnetic recording medium; a device that supports the slider and that positions said slider relative to said magnetic recording medium.

19 . The write head of claim 1 wherein both said planar distal edges of said LS layer and said LET layer are coplanar.

Assignees

• Headway Tech Inc

Inventors

• Liu Ying
• Tang Yuhui
• Liu Yue
• Hirata Kei

Classifications

• G11B5/1278 Primary

  specially adapted for magnetisations perpendicular to the surface of the record carrier · CPC title

• G11B5/315

  Shield layers on both sides of the main pole, e.g. in perpendicular magnetic heads · CPC title

• G11B5/11 Primary

  Shielding of head against electric or magnetic fields · CPC title