IP Library Granted Patent US 8,999,535
Granted Patent B2
US 8,999,535 · App. 13/149,540 · Granted Apr 7, 2015

Perpendicular magnetic recording media

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Quick Facts
Patent No.
US 8,999,535
App. No.
13/149,540
Granted
Apr 7, 2015
Kind
B2
Abstract

[Problem] An object is to provide a perpendicular magnetic recording medium in which a narrower track width is achieved by enhancing an exchange coupling magnetic field Hex of a soft magnetic layer so that a higher recording density can be achieved. [Solution] A perpendicular magnetic recording medium according to the present invention is configured to include a magnetic recording layer 122 that records a signal, and a soft magnetic layer 114 provided below the magnetic recording layer, on a base 110 on a main surface of which textures are formed, wherein the textures includes first textures 110 a that is linear rails in a certain direction, and second textures 110 b that are trails intersecting at a predetermined angle with the first textures; and the angle of intersection between the first textures and the second textures is 10° or less.

Claims (5)

1. A perpendicular magnetic recording medium comprising a magnetic recording layer that records a signal, and a soft magnetic layer provided below the magnetic recording layer, on a base on a main surface of which textures are formed, wherein

the textures comprise first textures that are linear trails intersecting with a circumferential direction of the base at a first angle, and second textures that are linear trails intersecting at a predetermined angle with the first textures, the second textures intersecting with the circumferential direction of the base at a second angle that is different from the first angle;

the base has a surface roughness Ra of 0.085 nm to 0.09 nm; and

the angle of intersection between the first textures and the second textures is from 3° to 8°.

2. The perpendicular magnetic recording medium according to claim 1 , wherein the textures are formed by relative movement between the base and a polishing tape that polishes the main surface of the base.

Assignments (6)
PATENT COLLATERAL AGREEMENT - A&R LOAN AGREEMENT Recorded Aug 21, 2023
From: WESTERN DIGITAL TECHNOLOGIES, INC.
To: JPMORGAN CHASE BANK, N.A.
Reel/Frame 064715/0001 →
PATENT COLLATERAL AGREEMENT - DDTL LOAN AGREEMENT Recorded Aug 21, 2023
From: WESTERN DIGITAL TECHNOLOGIES, INC.
To: JPMORGAN CHASE BANK, N.A.
Reel/Frame 067045/0156 →
RELEASE OF SECURITY INTEREST AT REEL 053926 FRAME 0446 Recorded Feb 8, 2022
From: JPMORGAN CHASE BANK, N.A.
To: WESTERN DIGITAL TECHNOLOGIES, INC.
Reel/Frame 058966/0321 →
SECURITY INTEREST Recorded Sep 29, 2020
From: WESTERN DIGITAL TECHNOLOGIES, INC.
To: JPMORGAN CHASE BANK, N.A., AS AGENT
Reel/Frame 053926/0446 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 9, 2020
From: WD MEDIA (SINGAPORE) PTE. LTD
To: WESTERN DIGITAL TECHNOLOGIES, INC.
Reel/Frame 053180/0398 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 22, 2011
From: TACHIBANA, TOSHIAKI
To: WD MEDIA (SINGAPORE) PTE.LTD.
Reel/Frame 027267/0887 →