IP Library Granted Patent US 6,916,558
Granted Patent B2
US 6,916,558 · App. 10/778,186 · Granted Jul 12, 2005

Magnetic disk using a glass substrate

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Quick Facts
Patent No.
US 6,916,558
App. No.
10/778,186
Granted
Jul 12, 2005
Kind
B2
Abstract

In a magnetic disk having a glass substrate, an amorphous underlayer is formed on the glass substrate. A magnetic layer is formed on the amorphous underlayer. The glass substrate is provided with a texture formed to induce magnetic anisotropy in the magnetic layer. The amorphous underlayer contains a group IVa element on a glass substrate side and a group Va element on a magnetic layer side.

Claims (12)

1. A magnetic disk having a glass substrate, comprising:

an amorphous underlayer formed on the glass substrate; and

a magnetic layer formed on the amorphous underlayer;

the glass substrate being provided with a texture formed to induce magnetic anisotropy in the magnetic layer;

wherein the amorphous underlayer is formed immediately above the glass substrate provided with the texture, and

the amorphous underlayer comprises a first amorphous layer made of a first material comprising at least one of Ti or Zr added to Cr and a second amorphous layer made of a second material comprising at least one of Nb and Ta added to Cr, the second amorphous layer being formed directly on the first amorphous layer.

2. A magnetic disk according to claim 1 , further comprising:

a seed layer which has a B2 crystal structure and which is formed between the amorphous underlayer and the magnetic layer.

3. A magnetic disk according to claim 1 , wherein:

the magnetic layer includes an exchange coupling film.

4. A magnetic disk according to claim 1 , wherein:

the magnetic disk is loaded in a hard drive of a load/unload system.

Assignments (3)
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 17, 2004
From: UMEZAWA, TEIICHIRO; TOMIYASU, HIROSHI; MOROISHI, KEIJI
To: HOYA CORPORATION; HOYA MAGNETICS SINGAPORE PTE. LTD.
Reel/Frame 014999/0361 →