JPH01267834A - Production of thin-film magnetic recording medium - Google Patents

Abstract

PURPOSE:To obviate the generation of burrs by sticking a polishing agent to a holding body having elasticity and pressing the holding body to a substrate surface or underlying film surface while relatively changing the positions of the substrate and the holding body, thereby forming fine ruggedness. CONSTITUTION:The fine concentrical ruggedness is formed to the substrate 5 or the underlying film provided on the substrate 5 surface. The formation of the fine ruggedness is executed by sticking the polishing agent 1 to the holding body having elasticity and pressing the holding body to the polishing agent 5 surface or the underlying film surface while relatively changing the positions of the substrate 1 and the holding body. The holding body to which the polishing agent 1 is stuck may be a holding body having elasticity and may be preferably, for example, a nonwoven fabric 4 or the like. The polishing agent 1 is stuck to the nonwoven fabric 4 without being fixed thereto and does not generate undue stress in cutting power. The thin-film magnetic disk is thereby produced without generating the burrs.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a magnetic recording medium, and particularly to a method of manufacturing a thin film magnetic recording medium.

[Conventional technology]

Thin film magnetic recording media, particularly sputtered disks and plated disks, have finer surface roughness than conventional coated disks. For this reason, it is well known that when a magnetic head is stopped on a magnetic disk, the magnetic head is attracted to the magnetic disk.

In order to prevent this, fine concentric surface roughening is performed in the circumferential direction of the substrate on the substrate surface of the magnetic disk or on the surface of the base film provided on the substrate surface, to the extent that the electromagnetic characteristics are not degraded. It forms fine irregularities.

Conventionally, this processing method involves using an abrasive tape with an abrasive fixedly held on the tape, pressing the abrasive tape against the substrate while rotating the substrate, and processing the abrasive tape while feeding it.

In addition, related to this, Japanese Patent Application Laid-Open No. 59-117
735 is mentioned.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, no consideration was given to the fact that "burrs" remain. That is, in the abrasive tape used in the above-mentioned prior art, as shown in FIG. 2, the abrasive is held on a holding base in an arbitrary shape, and the size of the unevenness formed by the abrasive is irregular. When processing a substrate with this abrasive tape, the abrasive material is fixed to the holding base by the holding material, so the abrasive material is applied with uniform pressure.
Regardless of the cutting force of each abrasive, a constant pressure is applied, which tends to deteriorate the cutting quality.

In addition, since the abrasive is fixed, it tends to become clogged with chips, which can impede sharpness. For this reason, as shown in FIG. 3, the chips tend to bulge and bulge, so-called burrs 6.

When a magnetic film is formed on the substrate in this state, the burrs remain as bulges and form protrusions. Next, when the protrusions are removed in a burnishing process, the size of the protrusions damages the magnetic medium and deteriorates the electromagnetic characteristics. The same thing happens when the magnetic head is raised 77, and both are damaged due to collision with the remaining protrusion that could not be removed. Therefore, the thin film magnetic recording medium manufactured by the above-mentioned conventional technique has problems with respect to electromagnetic characteristics and life span.

Note that it is troublesome to remove dust-generated burrs by finishing machining because the burrs escape into the grooves formed by surface roughening machining.

An object of the present invention is to provide a method for manufacturing a thin film magnetic recording medium without causing burrs.

[Means to solve the problem]

The above purpose is to form fine concentric irregularities on the substrate of a thin film magnetic recording medium or on the base film provided on the substrate surface, and then
In a method for manufacturing a thin film magnetic recording medium in which a thin film magnetic recording film is formed, the formation of the fine irregularities is achieved by attaching an abrasive to an elastic holder and adjusting the relative positions of the substrate and the holder. This is achieved by a method of manufacturing a thin film magnetic recording medium, which is characterized in that the holding body is pressed against the substrate surface or the underlying film surface while changing the magnetic field.

The above-mentioned concentric circular shape does not have to be a perfect concentric circle, and also means that one groove of the unevenness may not be a perfect circle but a part of a circle, that is, a circular arc. For example, a portion may be spiral. As described above, since the unevenness is for preventing the magnetic head from adhering to the magnetic recording medium, it is sufficient that the unevenness is formed in the concentric direction.

The holder to which the abrasive is attached may be any elastic holder, and is preferably made of nonwoven fabric, for example. FIG. 1 shows an example of a state in which an abrasive is attached to a nonwoven fabric. The abrasive 1 is attached to the non-woven fabric 4 without being fixed, so that the cutting force does not become unreasonable and clogging due to chips does not occur. It is preferable that the holder is in the form of a tape and used while constantly updating the contact points.

In the present invention, it is preferable to form the above-mentioned irregularities while further vibrating the holding body, the substrate, or both in the radial direction of the above-mentioned concentric circles. This vibration can further prevent clogging caused by chips.

[Effect]

In the present invention, since the abrasive is not fixed by a holder, the cutting force of the abrasive can be applied softly, and burrs are less likely to occur. In addition, machining while excitation makes it easier to discharge chips, making it even more difficult for burrs to occur.

〔Example〕

An embodiment of the present invention will be described using FIG. 4.

FIG. 4 shows a surface roughening device. A disk substrate 5, which is a workpiece, is attached to a spindle shaft 7 and rotated at a predetermined speed. Holding tape drive unit 8 for polishing
has a feed reel 9 and a take-up reel 10. The holding tape 14 is wound from the feed reel 9 onto the take-up reel 10 at a predetermined speed.

A fixed amount of polishing liquid 11°, for example, diamond polishing liquid, is supplied from the polishing liquid tank 12 to the holding tape 14, and the nozzle 1
It is dripped from 3. The holding tape 14 that has absorbed the abrasive liquid and has the abrasive agent attached thereto is moved to a pressurizing guide 16 via a leaf spring 15.
, and comes into contact with the surface of the substrate 5. Note that the holding tape 14b on the right side of the drawing is also in contact with the substrate by a leaf spring and a pressure guide, but these leaf springs and pressure guides are not shown because they are located at the back of the spindle shaft 7.

The +1 movement unit 8 can be moved by the guide pin 20 from the front to the back of the drawing and vice versa, and by this movement, the holding tape 14 can be moved to the inner and outer peripheries of the substrate 5.

Furthermore, the holding tape 14 is vibrated at a predetermined frequency in the radial direction of the substrate by the ultrasonic vibrator 17 .

FIG. 5 shows the relationship between the substrate rotation speed and the burr size of a substrate processed using this apparatus. Figure 5 shows the results without vibration. Although it depends on the abrasive grain size (average grain size), the size of the burrs becomes smaller when the substrate rotation speed is 50 Or p m or more. Note that the substrate rotation speed is low, for example, 100 to 2
Although the size of the burr is small even at 00 ppm,
It is not possible to form a sufficient amount of unevenness on the substrate. It is preferable to use an abrasive grain with a diameter of 1 to 5 μrn.

FIG. 6 is a diagram showing the relationship between the number of rotations of the substrate and the size of the burr when vibration is applied. When vibration is applied, it can be used at a substrate rotation speed of 400 rpm or more. The frequency of excitation is preferably in the range of 10 to 100 to Iz.

10 to 50I (the range of z is more preferable).

FIG. 7 is a diagram showing the relationship between the pressure applied to the nonwoven fabric and the size of burrs. When the pressure increases, the burr becomes dog-sized. On the other hand, if the pressing force is too small, it will be difficult to form unevenness, so a pressing force of about 0.2 to 2 kg/cm2 is preferable.

Using the surface roughening plate obtained in Example 2, a piezo element was mounted on the flying slider, and the number of protrusions was detected while changing the flying height. The number of protrusions per surface is 0 even when the diameter is in the range of 0.2 to 0.05 μm.
We confirmed that it is possible to obtain information that indicates the number of individuals.

In addition, as a comparison, in the case of a board whose surface was roughened by the conventional method, the number of protrusions was approximately 10 to several IO, as shown by 19 in the same figure, even when the flying height was 0.2 μm, and there were differences depending on the processing method. was confirmed to be significant. In addition, when the contact point was detected with a piezo element and the surface Re was performed, it was found that the protrusion was caused by paris during polishing.

Further, after processing a substrate having a base film in the same manner as above, a magnetic film and a protective film are formed by sputtering and plating methods to manufacture a magnetic disk, and the piezo element is mounted on it;
When defect inspection was performed using the upper slider, the same results as above were obtained.

〔Effect of the invention〕

According to the present invention, thin film magnetic disks can be manufactured without causing burrs. Therefore, when using the magnetic disk manufactured according to the present invention, the flying height of the magnetic head can be lowered.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the nonwoven fabric to which the abrasive used in the present invention is attached, and FIG. 2 is a cross-sectional view of the abrasive tenip used in the conventional method.
FIG. 3 is a partial cross-sectional perspective view of a substrate subjected to surface roughening processing, FIG. 4 is a schematic front view of an example of a processing apparatus for carrying out the present invention, and FIGS. 5, 6, 7, and 8. , are diagrams for explaining the present invention. 1... Abrasive agent 2... Abrasive agent holding part 3...
Abrasive agent holding base 4...Nonwoven fabric 5...Substrate 6 Burr 7 - Spindle shaft 8 Holding tape drive unit 9...Feed reel 10...Take-up reel 11...
- Polishing liquid 12... Polishing liquid tank 13... Nozzle 14 Holding tape 15... Pressure plate spring 16... Pressure guide 17 - Ultrasonic vibration part 1
8... Present invention 19 Conventional example 20... Guide pin agent Junnosuke Nakamura Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] 1. Manufacturing of a thin film magnetic recording medium by forming fine concentric irregularities on the substrate of the thin film magnetic recording medium or on a base film provided on the substrate surface, and then forming a thin film magnetic recording film. In the method, the formation of the fine irregularities is achieved by attaching an abrasive to an elastic holder, and while relatively changing the position of the substrate and the holder, the holder is attached to the substrate surface or the base film. A method for manufacturing a thin film magnetic recording medium, characterized in that the method is carried out by pressing it against a surface. 2. The method of manufacturing a thin film magnetic recording medium according to claim 1, wherein the unevenness is formed while vibrating the holder or the substrate or both in the radial direction of the concentric circles.