Unlock instant, AI-driven research and patent intelligence for your innovation.

Method for testing magnetic recording medium and method for production of magnetic recording medium including testing step

A technology of magnetic recording medium and test head, applied in magnetic recording, data recording, measurement of magnetic variables, etc., can solve problems such as hindering accurate detection and reducing the reliability of magnetic recording medium.

Inactive Publication Date: 2009-10-14
RESONAC HOLDINGS CORPORATION
View PDF3 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This noise entails the problem that the signal will hide the signal originating from the protrusions and thus prevent accurate detection of protrusions on the surface of the magnetic recording medium
Among the protrusions on the surface of the magnetic recording medium, especially the fine protrusions hidden in the noise and missed detection, bring about the problem of lowering the reliability of the magnetic recording medium

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
  • Method for testing magnetic recording medium and method for production of magnetic recording medium including testing step
  • Method for testing magnetic recording medium and method for production of magnetic recording medium including testing step
  • Method for testing magnetic recording medium and method for production of magnetic recording medium including testing step

Examples

Experimental program
Comparison scheme
Effect test

example 1-1

[0057] For the non-magnetic substrate, an amorphous glass substrate manufactured by HOYA Corporation was used. The glass substrate measured an outer diameter of 65 mm, an inner diameter of 25 mm, and a plate thickness of 1.270 mm.

[0058] The substrate was textured, thoroughly cleaned and dried, and set in a DC magnetron sputtering apparatus (manufactured by Anelva (Japan) Corporation and sold under the trade name "C3010"). The device is evacuated until 2 x 10 -7 Torr (2.7×10 -5Pa) vacuum, and by using a target of a Cr-Mn alloy (Cr: 70at%, Mn: 30at%), a Cr-Mn alloy (Cr: 70at%, Mn: 30at%) was laminated with a thickness of 6 nm on the substrate as Non-magnetic lining. By using a target made of a Co-Cr-Pt-B alloy (Co: 60at%, Cr: 20at%, Pt: 13at%, B: 7at%), Co-Cr-Pt-B with a film thickness of 17nm was formed The alloy layer was used as a magnetic layer, followed by laminating a protective film (carbon) with a thickness of 3 nm. The Ar pressure during film formation was set a...

example 1-2

[0062] The six magnetic recording media that have been observed to have output signals above the limit level are evaluated here. Here, the evaluation conditions of Example 1-1 were further tightened by setting the skid height to 0.19 microinches and the limit level to 40%. Set the bandpass filter from 400kHz to 3000kHz. These six magnetic recording media must have been found to have an output signal from the test head with the thermal element below the limit level. Signals emitted from the magnetic recording medium of Example 1-1 and exceeding the limit level must be considered to originate from ridges on the surface of the magnetic recording medium, and the magnitude of these ridges is considered to be within the range of the test head with thermally sensitive elements. follow level. This result shows that the signal from the ridge component of the test head with the thermal element can be reduced by increasing the lower limit of the bandpass filter from 100kHz to 400kHz, a...

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
surface roughnessaaaaaaaaaa
thicknessaaaaaaaaaa
thicknessaaaaaaaaaa
Login to View More

Abstract

A method for testing a magnetic recording medium tests a magnetic recording medium provided on a non-magnetic substrate (1) with at least a magnetic layer (3) for surface characteristics by using a testing head possessing a heat sensitive element. The method starts from scanning the surface of the magnetic recording medium by using a testing head possessing a heat sensitive element. By this scanning, a signal component of low frequency originating in the swell of the surface of the magnetic recording medium is separated from the signal emitted from the testing head. The protrusion on the surface of the magnetic recording medium is detected from the signal of high frequency remaining after the separation.

Description

[0001] Cross References to Related Applications [0002] This application is based on an application filed under 35 U.S.C. §111(a) under 35 U.S.C. §119(e)(1), claiming Japanese Patent Application No. filed on November 13, 2006 under 35 U.S.C. 2006-306472 and priority of Japanese Patent Application No. 2007-174765 filed on July 3, 2007. technical field [0003] The present invention relates to a method of testing a magnetic recording medium to be used as a magnetic recording and reproducing device, a so-called hard disk drive, and to a method of manufacturing a magnetic recording medium including a testing step of the testing method. Background technique [0004] The recording density of magnetic recording and reproducing devices (hard disk drives) has reached the level of 150 Gbit / square inch. It is said that the recording density will continue to grow at an annual rate of 30% in the future. Therefore, research is being advanced toward the development of a magnetic recordi...

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): G11B5/84G11B5/00
CPCG11B5/4555G01R33/1207G11B19/048G11B5/84
Inventor 坂野洋平塚田耕司
Owner RESONAC HOLDINGS CORPORATION