IP Library Granted Patent US 8,795,857
Granted Patent B2
US 8,795,857 · App. 12/665,271 · Granted Aug 5, 2014

Perpendicular magnetic recording medium and manufacturing method of the same

Inventors: Kenji Ayama (Singapore, SG); Tokichiro Sato (Singapore, SG); Teiichiro Umezawa (Singapore, SG); Masafumi Ishiyama (Singapore, SG)
Assignee: WD Media (Singapore) Pte. Ltd.
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Quick Facts
Patent No.
US 8,795,857
App. No.
12/665,271
Granted
Aug 5, 2014
Kind
B2
Abstract

A perpendicular magnetic recording medium of the invention is characterized by having, on a disk substrate 110 , a soft magnetic layer 14 , a magnetic recording layer 22 , a continuous layer 24 magnetically continuous in the in-plane direction of the substrate, a blocking layer 25 for blocking shock imposed on the continuous layer, and a medium protective layer 28 containing carbon formed on the blocking layer.

Claims (13)

1. A perpendicular magnetic recording medium comprising:

a substrate;

a soft magnetic layer disposed above a surface of the substrate;

a magnetic recording layer disposed above the soft magnetic layer;

a continuous layer which is magnetically continuous in the in-plane direction of the substrate disposed above the magnetic recording layer;

a blocking layer disposed above the continuous layer and CVD (Chemical Vapour Deposition) deposited directly on the continuous layer to have a thickness of approximately 0.25 nm for blocking shock imposed on the continuous layer when carbon atoms are applied during formation of a medium protective layer; and

the medium protective layer containing carbon and formed on the blocking layer,

wherein the blocking layer is non-magnetic and formed only of amorphous CrTi, and

wherein the medium protective layer is formed on the blocking layer while a bias voltage of 100 V to 300 V is applied to the substrate.

2. The perpendicular magnetic recording medium according to claim 1 , wherein the medium protective layer is formed using a CVD (Chemical Vapour Deposition) method or a sputtering method.

3. The perpendicular magnetic recording medium according to claim 1 , wherein the blocking layer is formed of an element contained in the continuous layer.

4. The perpendicular magnetic recording medium according to claim 1 , wherein the medium protective layer contains diamond-like carbon.

5. The perpendicular magnetic recording medium according to claim 1 , wherein the continuous layer contains a Co—Cr alloy comprising CoCrPtB.

Assignments (8)
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 →
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 →
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 →
CORRECTIVE ASSIGNMENT TO CORRECT THE NAME OF ASSIGNEE TO WD MEDIA (SINGAPORE) PTE. LTD. PREVIOUSLY RECORDED ON REEL 024611 FRAME 0396. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT. Recorded Sep 20, 2010
From: HOYA MAGNETICS SINGAPORE PTE LTD; HOYA CORPORATION
To: WD MEDIA (SINGAPORE) PTE. LTD.
Reel/Frame 025008/0948 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 30, 2010
From: HOYA MAGNETICS SINGAPORE PTE LTD; HOYA CORPORATION
To: WESTERN DIGITAL CORPORATION; WD MEDIA (SINGAPORE) PTE. LTD.
Reel/Frame 024611/0396 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 4, 2010
From: AYAMA, KENJI; SATO, TOKICHIRO; UMEZAWA, TEIICHIRO; ISHIYAMA, MASAFUMI
To: HOYA CORPORATION; HOYA MAGNETICS SINGAPORE PTE. LTD
Reel/Frame 023896/0142 →
Priority Claims (1)
JP 2007-256914 · Sep 28, 2007 · national
Continuity (1)
Related Publication 20100196740A1 · Aug 5, 2010