Perpendicular magnetic recording head with side shield and magnetic disk apparatus

• US 8,169,741 B2
• Filed: 05/03/2007
• Issued: 05/01/2012
• Est. Priority Date: 05/11/2006
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Taguchi, Tomoko, Funayama, Tomomi, Aoyagi, Yuka, Koui, Katsuhiko
• Primary Examiner(s): Miller, Brian
• Application Number:
  US11/797,447
• Publication Number:
  US 20070268626A1
• Time in Patent Office: 1,825 Days
• Field of Search: 360/125.3, 360/125.16
• US Class Current: 360/125.3
• CPC Class Codes: G11B 5/11 Shielding of head against electric or magnetic fields
• CPC Class Codes: G11B 5/1278 specially adapted for magnetisations perpendicular to the surface of the record carrier
• CPC Class Codes: G11B 5/3116 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 Class Codes: G11B 5/3143 including additional layers for improving the electromagnetic transducing properties of the basic structure, e.g. for flux coupling, guiding or shielding G11B5/3116, G11B5/312 take precedence
• CPC Class Codes: G11B 5/315 Shield layers on both sides of the main pole, e.g. in perpendicular magnetic heads

Abstract

According to one embodiment, a perpendicular magnetic recording head includes a main pole which generates a recording magnetic field, a return pole which forms a closed magnetic circuit for the recording magnetic field, and a side shield magnetically spaced from the main pole in a cross-track direction in which a point on a trailing edge of the side shield which is closest to the main pole is positioned on a leading side of a trailing edge of the main pole.

Claims

1. A perpendicular magnetic recording head comprising:

a main pole which generates a recording magnetic field;

a return pole which forms a closed magnetic circuit for the recording magnetic field; and

a single side shield facing side edges on a leading side of the main pole and a leading edge of the main pole, the single side shield being magnetically spaced from the main pole in a cross-track direction and in a down-track direction,

wherein a point on a trailing edge of the side shield which is closest to the main pole is positioned on a leading side of a trailing edge of the main pole, and

wherein a ratio SSW/PL of a distance SSW between a leading edge of the return pole and the point on the trailing edge of the side shield which is closest to the main pole to a pole length PL of the main pole is ⅓

to 1.

2. The perpendicular magnetic recording head according to claim 1, wherein a shortest distance SSP between the main pole and the side shield is shorter than the distance SSW between the leading edge of the return pole and the point on the trailing edge of the side shield which is closest to the main pole.

3. The perpendicular magnetic recording head according to claim 1, wherein a ratio SSP/SSW of the shortest distance SSP between the main pole and the side shield to the distance SSW between the leading edge of the return pole and the point on the trailing edge of the side shield which is closest to the main pole is 0.1 or more and 0.7 or less.

4. The perpendicular magnetic recording head according to claim 1, wherein the ratio SSP/SSW of the shortest distance SSP between the main pole and the side shield to the distance SSW between the leading edge of the return pole and the point on the trailing edge of the side shield which is closest to the main pole satisfies the following relation:

0.1<

SSP/SSW <

−

0.034×

θ

_b +0.67,

where θ

_b denotes a bevel angle [deg] of the main pole.

5. A perpendicular magnetic recording head comprising:

a main pole which generates a recording magnetic field;

a return pole which forms a closed magnetic circuit for the recording magnetic field; and

a single side shield facing side edges on a leading side of the main pole and a leading edge of the main pole, the single side shield being magnetically spaced from the main pole in a cross-track direction and in a down-track direction,

wherein a point on a trailing edge of the side shield which is closest to the main pole is positioned on a leading side of a trailing edge of the main pole,

wherein a ratio SSW/PL of a distance SSW between a leading edge of the return pole and the point on the trailing edge of the side shield which is closest to the main pole to a pole length PL of the main pole is ⅓

to 1, and

wherein a ratio SSP/SSW of a shortest distance SSP between the main pole and the side shield to the distance SSW between the leading edge of the return pole and the point on the trailing edge of the side shield which is closest to the main pole is 0.1 or more and 0.7 or less.