Magnetic head for perpendicular magnetic recording capable of preventing unwanted erasure

Patent metadata

Field	Value
Publication number	US-9653100-B1
Application number	US-201514945004-A
Country	US
Kind code	B1
Filing date	Nov 18, 2015
Priority date	Nov 18, 2015
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

A magnetic head includes a coil, a main pole, a write shield, and a return path section. The coil includes a coil element located on the trailing side of the main pole. The coil element has a front end face facing toward the medium facing surface. The return path section includes a first portion, a second portion, and an intermediate film interposed between the first portion and the second portion. Part of the first portion is interposed between the medium facing surface and the front end face of the coil element. Part of the second portion is interposed between the first portion and the front end face of the coil element.

First claim

What is claimed is:

1. A magnetic head for perpendicular magnetic recording, comprising:
a medium facing surface configured to face a recording medium;
a coil for producing a magnetic field corresponding to data to be written on the recording medium;
a main pole having an end face located in the medium facing surface, the main pole being configured to pass a magnetic flux corresponding to the magnetic field produced by the coil, and to produce a write magnetic field for use to write the data on the recording medium by means of a perpendicular magnetic recording system;
a write shield formed of a magnetic material;
a gap section formed of a nonmagnetic material and located between the main pole and the write shield; and
a first return path section located on a front side in a direction of travel of the recording medium relative to the main pole, the first return path section connecting the write shield to a part of the main pole located away from the medium facing surface so that a first space is defined by the main pole, the gap section, the write shield, and the first return path section, the first return path section including:
a first portion formed of a first magnetic material;
a second portion formed of a second magnetic material, the second portion being located farther from the medium facing surface than is the first portion; and
a first intermediate film interposed between the first portion and the second portion, a thickness of the first intermediate film in a direction perpendicular to the medium facing surface being smaller than a maximum thickness of the first portion in the direction perpendicular to the medium facing surface, and no portion of the first intermediate film being in the medium facing surface,

wherein the coil includes a first coil element extending to pass through the first space,
the first coil element has a front end face facing toward the medium facing surface,
at least part of the first portion of the first return path section is interposed between the medium facing surface and the front end face of the first coil element, and
at least part of the second portion of the first return path section is interposed between the first portion of the first return path section and the front end face of the first coil element.

2. The magnetic head for perpendicular magnetic recording according to claim 1 , wherein the first intermediate film contains an element constituting the first magnetic material and oxygen.

3. The magnetic head for perpendicular magnetic recording according to claim 1 , wherein the first intermediate film is formed of a nonmagnetic material.

4. The magnetic head for perpendicular magnetic recording according to claim 1 , wherein the second magnetic material is higher in saturation flux density than the first magnetic material.

5. The magnetic head for perpendicular magnetic recording according to claim 1 , wherein
the write shield includes a top shield located on the front side in the direction of travel of the recording medium relative to the main pole, and
the first portion of the first return path section is located on the front side in the direction of travel of the recording medium relative to the top shield.

6. The magnetic head for perpendicular magnetic recording according to claim 1 , wherein
the front end face of the first coil element has a first end closest to the main pole and a second end opposite to the first end, and
the front end face is inclined with respect to the medium facing surface and the direction perpendicular to the medium facing surface such that the second end is at a greater distance from the medium facing surface than is the first end.

7. The magnetic head for perpendicular magnetic recording according to claim 1 , wherein
the first return path section further includes a third portion and a second intermediate film, the third portion being formed of the second magnetic material and interposed between the medium facing surface and the first portion, the second intermediate film being interposed between the first portion and the third portion, and
a thickness of each of the third portion and the second intermediate film in the direction perpendicular to the medium facing surface is smaller than the maximum thickness of the first portion in the direction perpendicular to the medium facing surface.

8. The magnetic head for perpendicular magnetic recording according to claim 1 , further comprising a second return path section formed of a magnetic material and located on a rear side in the direction of travel of the recording medium relative to the main pole, wherein
the second return path section connects the write shield to a part of the main pole located away from the medium facing surface so that a second space is defined by the main pole, the gap section, the write shield and the second return path section, and
the coil includes a second coil element extending to pass through the second space.

9. The magnetic head for perpendicular magnetic recording according to claim 1 , wherein
the write shield includes a top shield located on the front side in the direction of travel of the recording medium relative to the main pole,
the first portion of the first return path section is located on the front side in the direction of travel of the recording medium relative to the top shield,
the front end face of the first coil element has a first end closest to the main pole and a second end opposite to the first end,
the front end face is inclined with respect to the medium facing surface and the direction perpendicular to the medium facing surface such that the second end is at a greater distance from the medium facing surface than is the first end,
the first return path section further includes a connection section having a columnar shape and connecting the second portion to the part of the main pole located away from the medium facing surface,
the magnetic head further comprises an insulating film interposed between the connection section and the first coil element and between the main pole and the first coil element, and
the first coil element, the insulating film and the connection section have respective top surfaces coplanar with each other.

10. A manufacturing method for the magnetic head for perpendicular magnetic recording of claim 1 , comprising steps of:
forming the coil;
forming the main pole;
forming the write shield;
forming the gap section; and
forming the first return path section, which includes:
forming a first magnetic layer by plating, the first magnetic layer being formed of the first magnetic material and including the first portion; and
forming a second magnetic layer by plating after the first magnetic layer is formed, the second magnetic layer being formed of the second magnetic material and including the second portion.

11. The manufacturing method for the magnetic head for perpendicular magnetic recording according to claim 10 , wherein
the first intermediate film contains an element constituting the first magnetic material and oxygen, and
the first intermediate film is formed by oxidation of a part of the first magnetic layer after the first magnetic layer is formed, the part of the first magnetic layer including a surface of the first magnetic layer.

12. The manufacturing method for the magnetic head for perpendicular magnetic recording according to claim 10 , wherein
the first intermediate film is formed of a nonmagnetic material, and
the step of forming the first return path section further includes forming the first intermediate film between the step of forming the first magnetic layer and the step of forming the second magnetic la

Assignees

• Sasaki Yoshitaka
• Ito Hiroyuki
• Sato Kazuki
• Tanemura Shigeki
• Ikegawa Yukinori
• Takano Kenichi
• Headway Tech Inc

Inventors

• Sasaki Yoshitaka
• Ito Hiroyuki
• Sato Kazuki
• Tanemura Shigeki
• Ikegawa Yukinori
• Takano Kenichi

Classifications

• G11B5/17

  Construction or disposition of windings · CPC title

• G11B5/1278 Primary

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

• G11B5/115

  Shielding devices arranged between heads or windings ({G11B5/265} , G11B5/29 take precedence) · CPC title

• G11B5/3146

  magnetic layers · CPC title

• G11B5/3116

  Shaping of layers, poles or gaps for improving the form of the electrical signal transduced, e.g. for shielding, contour effect, equalizing, side flux fringing, cross talk reduction between heads or between heads and information tracks (G11B5/3113, G11B5/245 take precedence) · CPC title