Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Substrate for a perpendicular magnetic recording medium and a perpendicular magnetic recording medium using the substrate

A technology of perpendicular magnetic recording and disk substrate, applied in the direction of the base layer of the recording layer, magnetic recording, magnetic recording layer, etc., can solve the problems of high-density recording, low production cost, etc., achieve good recording and reproduction performance, and cheap The effect of production

Inactive Publication Date: 2005-10-05
FUJI ELECTRIC CO LTD
View PDF0 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0024] As mentioned above, the conventional technology can hardly obtain the backing layer of the perpendicular magnetic recording medium which allows high-density recording and suppresses spike noise and still has low production cost and satisfactory mass-production capability

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Substrate for a perpendicular magnetic recording medium and a perpendicular magnetic recording medium using the substrate
  • Substrate for a perpendicular magnetic recording medium and a perpendicular magnetic recording medium using the substrate
  • Substrate for a perpendicular magnetic recording medium and a perpendicular magnetic recording medium using the substrate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0105] manufacture figure 1 Substrate shown

[0106] A disk-shaped Al-Mg alloy plate with a nominal diameter of 3.5 inches was used as figure 1 The non-magnetic substrate in 1. The substrate surface is cleaned by alkaline cleaning and acid etching and zincated (zinc immersion plating) as a starting reaction layer for electroless Ni-P coating. Then, use a commercially available electroless Ni-P plating solution (NIMUDENHDX manufactured by C.Uyemura & Co., Ltd.) for hard disk substrates to be controlled under the following conditions—the nickel concentration is 6.0 ± 0.1g / L, the pH value is 4.5±0.1, and the liquid temperature is 92±1° C.—a non-magnetic Ni-P alloy adhesion layer 2 with a thickness ranging from 0-10 μm is formed in the plating bath. The average phosphorus concentration in the non-magnetic Ni-P coating is 20 at%.

[0107] Subsequently, a soft magnetic underlayer 3 of CoNiP alloy with a thickness ranging from 0.5 to 10 μm was formed using the plating bath (1) s...

Embodiment 2

[0129] Manufactured in the same manner as in Example 1 figure 1 In the substrate 10 for perpendicular magnetic recording media, only the thickness of the adhesive layer 2 is 5.0 μm, the thickness of the soft magnetic underlayer 3 is 1.5 μm, and through the range shown in the plating bath (2) of Table 3 The conditions of the plating bath were changed so that the average phosphorus concentration in the soft magnetic underlayer 3 varied between 3 at % and 25 at %. The average cobalt concentration in the soft magnetic underlayer 3 is 67 at % to 72 at % in the ratio of the number of cobalt and nickel atoms excluding phosphorus. When the phosphorus concentration is lower than 3 at%, it is found that the plating bath is very unstable and cannot be mass-produced.

[0130] nickel sulfate

7-12g / L

cobalt sulfate

7-12g / L

sodium hypophosphite

10-30g / L

Sodium citrate

20-80g / L

sodium tartrate

0-150g / L

sodium acetate

0-80g / ...

Embodiment 3

[0136] Manufactured in the same manner as in Example 1 figure 1 In the substrate 10 for perpendicular magnetic recording media, only the thickness of the adhesive layer 2 is 5.0 μm, the thickness of the soft magnetic underlayer is 1.5 μm, and by changing the range shown in the plating bath (3) of Table 4 The conditions of the plating bath were varied such that the average cobalt concentration in the soft magnetic underlayer 3 was in the range of 18.8 at% to 90.9 at% in the number of atoms of cobalt and nickel other than phosphorus. The average phosphorus concentration in the soft magnetic underlayer is 10 at% to 20 at%.

[0137] nickel sulfate

6-18g / L

cobalt sulfate

2-14g / L

sodium hypophosphite

10-20g / L

Sodium citrate

60g / L

pH

6.5±0.2 to 8±0.2 (through NaOH and H 2 SO 4

Adjustment)

liquid temperature

80±2℃

[0138] Then, manufacture as embodiment 1 figure 2 perpendicular magnetic recordin...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
thicknessaaaaaaaaaa
thicknessaaaaaaaaaa
surface roughnessaaaaaaaaaa
Login to View More

Abstract

An object of the invention is to provide a substrate for a perpendicular magnetic recording medium, the substrate exhibiting sufficient productivity, serving a function as a soft magnetic backing layer of the perpendicular magnetic recording medium, and securing surface hardness. The invention also provides a perpendicular magnetic recording medium using such a substrate. The substrate comprises a nonmagnetic base plate 1 composed of an aluminium alloy, an adhesion layer 2 formed on the nonmagnetic base plate and composed of a material containing at least nickel, and a soft magnetic underlayer 3 formed on the adhesion layer by 2 by means of an electroless plating method and containing phosphorus in a range of 3 at % to 20 at %, and cobalt at least 25 at % in a proportion of number of atoms of cobalt and nickel excluding the phosphorus (Co / (Co+Ni)); and a thickness of the adhesion layer is at least 0.1mum. A thickness of the soft magnetic underlayer is at least 0.2 mum and a sum of thickness of the adhesion layer and the thickness of the soft magnetic underlayer is at least 3mum.

Description

technical field [0001] The present invention relates to a substrate for a perpendicular magnetic recording medium and a perpendicular magnetic recording medium mounted on an external storage device of a computer and other magnetic recording devices, and more particularly to a perpendicular magnetic recording medium suitable for mounting on a hard disk drive (HDD), and to a substrate for such perpendicular magnetic recording media. Background technique [0002] A perpendicular magnetic recording system is attracting attention as a technology to replace the traditional longitudinal magnetic recording system to achieve high-density magnetic recording. [0003] In particular, as disclosed in Patent Document 1, there is known a double-layer perpendicular magnetic recording medium suitable for use in a perpendicular magnetic recording system to achieve high-density recording. A two-layer perpendicular magnetic recording medium is provided with a soft magnetic thin film called a s...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): G11B5/667A61B6/00G01N23/00G11B5/64G11B5/65G11B5/73G11B5/738G11B5/84G21K1/12H04N5/325H05G1/60
CPCG11B5/667
Inventor 上住洋之中岛典彦川田辰实樋口和人
Owner FUJI ELECTRIC CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com