JPH01140958A - Method of finishing disc and device therefor - Google Patents

Abstract

PURPOSE:To uniformly finish the outer surface of a disc such as a magnetic disc by maintaining the relative speed between a polishing tape and the disc constant, irrespective of a position to be processed, so as to remove micro projection on the outer surface of the disc uniformly and accurately over the entire surface thereof. CONSTITUTION:A pair of polishing tapes 1 in a machining head is made into press- contact with the front and rear surfaces of a disc 3 such as a magnetic disc or the like on rotation by a contact roller 2 while an abrasive material 9 is fed onto the outer surface of the disc 3. Simultaneously, a slide part of the machining head 12 reciprocates the latter radially of the disc 3 so that micro projections on the front and rear surfaces of the disc 3 are polished and removed by the polishing tapes 1. In this arrangement, the position of the slide part of the machining head is always detected by a linear scale 6 so that a control device 6' controls the rotational speed of a disc rotating motor 7 to maintain the relative speed between the polishing tapes 1 and the disc 3 at a machining point is maintained to be constant. As a result, the dynamic pressure by the polishing material 9 therebetween is made to be constant, thereby it is possible to finish the front and rear surfaces of the disc 3, uniformly and accurately in polishing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for finishing disks such as sputter disks and coated disks for magnetic disk devices for computers, and in particular, to a method and apparatus for finishing disks such as sputter disks and coated disks for magnetic disk devices for computers. In order to improve
The present invention relates to a disk finishing method and apparatus for efficiently and uniformly removing minute protrusions on a disk.

[Conventional technology] As a conventional technology, Japanese Patent Application Laid-open No. 106029/1983 "
"Magnetic disk manufacturing equipment," etc. This will be explained using FIG. 5.

FIG. 5 is a perspective view showing a conventional protrusion removing device.

In FIG. 5, the abrasive tape 1 is crimped onto the surface of the disc 3 rotating in the A direction via a pressurizer 20, and is slid back and forth in the radial direction (B direction) of the disc 3. , is a device for removing minute protrusions on the surface of the disk 3.

Note that the polishing tape 1 is wound up at a very low speed.

[Problems to be Solved by the Invention] In the above-mentioned prior art, the polishing tape is used to polish and remove minute protrusions on the disk surface on the inner and outer peripheries of the disk to create a smooth and homogeneous surface. Due to the difference in pressure applied due to the difference in the relative speed of the machining points on the disk, it was difficult to achieve a uniform surface condition by removing protrusions over the entire surface of the disk.

An object of the present invention is to maintain constant contact pressure between the disk surface and the polishing tape.

It is an object of the present invention to provide a method for removing minute protrusions on the entire surface of a disk and finishing the surface uniformly, and an apparatus directly used for carrying out the method.

[Means for Solving the Problems] The configuration of the disc finishing method of the present invention for solving the above problems includes supplying an abrasive to the surface of a rotating disc, while
In a disk finishing method in which minute protrusions on the surface of the disk are removed by compressing an abrasive tape, the relationship between the abrasive tape and the processing point on the rotating disk to which the abrasive tape is compressed is The speed is kept constant regardless of the position of the processing point.

Further, the configuration of the disk finishing device of the present invention is such that fine protrusions on the rotating disk are removed by compressing and bonding the abrasive tape to the surface of the rotating disk while supplying an abrasive. In an ellipsoidal plate finishing device, an abrasive tape is applied to a disk rotating shaft to which a disk can be attached, a disk rotating motor that drives this disk rotating shaft, and opposing processing points on both sides of the disk. a processing head having a pair of processing units capable of compressing and contacting a contact roller through the processing head;
A processing head sliding part that can reciprocate the processing head in the radial direction of the disk, a linear scale that detects the position of the processing head sliding part, and a linear scale that detects the position of the processing head based on the detected value by the linear scale. and a control device capable of controlling the rotation speed of the disc rotation motor so that the relative speed between the polishing tape and the disc at the processing point is constant regardless of the position of the processing point. be.

[Function] The function of the disk top finishing method of the present invention will be explained using FIG. 3. FIG. 3 is an enlarged schematic diagram of a processing section for explaining the disk finishing method of the present invention.

In FIG. 3, an abrasive 9 is applied to the surface of the rotating disk 3.
While supplying the polishing tape 1, fine protrusions 10 are
The case where a pressing force is applied to the polishing tape 1 moving at a relative speed V on the surface of the rotating disk 3 is shown. In this case, if the gap between the surface of the disk 3 and the polishing tape 1 is δ, the relationship between the dynamic pressure W generated at this time and the relative velocity V is expressed by the following equation.

δ2 Here, K is a constant depending on the abrasive flow and surrounding conditions, η
indicates the viscosity coefficient of the abrasive. Also, in Figure 3, δ
is the gap between the surface and the polishing tape, and h is the height of the protrusion, where δ and h are necessary conditions. In equation (1) above,
If K, η and δ are constant, the dynamic pressure W will be directly proportional to the relative velocity V.

When the abrasive tape slides back and forth in the radial direction on a rotating disc while being compressed, the relative velocity of the processing points on the disc surface is greater on the outer periphery than on the inner periphery.
The dynamic pressure experienced by the processing point is also greater at the outer periphery.

Therefore, in the present invention, in order to equalize the dynamic pressure applied to the machining points around the entire circumference of the disk, the following method was used.

Now, assuming that the distance gIr from the center of the disk to the processing point is N (rpm) and the rotation speed at this point is N (rpm), the winding speed of the abrasive tape is very small compared to the rotation speed of the disk, so the polishing tape is With respect to the dynamic speed, the relative speed V to the rotational speed at the processing point of the disk can be approximated as V'':2πr-N.

Here, the distance from the center of the disc is 1tr1? The rotation speed (rpm) when machining the machining point r2 is N machining and N machining, respectively.
2, and if the relative velocity V at each point is made equal, then r2
The rotation speed N2 at the machining point is N z = (r 1
/ r z ) X N l.

That is, by making the relative velocity of each point on the disk surface equal using the method described above, the dynamic pressure at each point can also be made constant.

By employing the above control method, fine protrusions scattered on the disk surface are uniformly removed and a homogeneous surface is obtained.

[Example] The present invention will be explained below with reference to Examples.

FIG. 1 is a front view of the main parts of an embodiment of the disk finishing apparatus of the present invention, and FIG. 2 is a side view of the main parts of the same.

First, the configuration of this embodiment will be explained using FIGS. 1 to 3. This disk finishing device is capable of simultaneously polishing and finishing both sides of the disk 3. That is, a processing head 12 includes a pair of processing units capable of bringing a contact roller 2 made of a viscoelastic body into pressure contact with the surface of a disk 3 by means of parallel springs 4a and 4b via an abrasive tape 1, and this processing head. 12 to the inner and outer circumference of the disk 3, a linear scale 6 that can constantly detect the movement position of the contact roller based on the radius dimension of the disk, and a linear scale 6 that rotationally drives the disk 3. A disc rotation motor 7, an abrasive supply mechanism (not shown) that supplies an abrasive 9 between the disc and the abrasive tape, and a control device 6 that controls the relative speed between the abrasive tape 1 and the disc 3 to be constant. ’.

Next, an embodiment of the disk finishing method of the present invention will be described using this disk finishing apparatus.

First, the disk 3 is installed on the disk rotating shaft 8. The processing head sliding part 5 is operated, and the polishing tape 1 is applied to the outer periphery of the disk.
is pressed by the contact roller 2, and while the abrasive tape 2 is wound up at a minute speed, the abrasive 9 is simultaneously supplied onto the disk, and while the disk 3 is rotated, the contact roller 2 and The polishing tape 1 is moved toward the inner circumference of the disk. The position of the sliding part 5 is constantly detected by the linear scale 6, and the controller 6 controls the position so that the relative speed between the processing point on the disk 3 and the polishing tape 1 is constant.
', the rotation speed of the disc rotating motor 7 is controlled. By controlling the relative speed of the movement of the polishing tape 1 and the disk 3 to be constant, the dynamic pressure caused by the intervening polishing agent 9 becomes equal. Therefore, since the polishing tape 1 acts on the disk 3 surface with a uniform pressing force over the entire disk surface,
The protrusion removal effect becomes uniform, and a disc with a highly precise smooth surface can be obtained.

The effect of this embodiment is that fine protrusions are removed all at once over the entire surface of both sides of the disk, with extremely high accuracy (protrusion height is 0.
05 μm or less) can be efficiently obtained.

In the case of this example, a liquid was supplied as an abrasive into the gap between the polishing tape and the disk surface, but even if an inert gas was supplied instead of the liquid, the relationship between the polishing tape and the disk When the relative velocity is kept constant at 1.200 (m/min) (500 (m/min) in the case of machining fluid), it is possible to uniformly reduce the fine protrusions over the entire surface of one disk. A homogeneous disk is obtained.

FIG. 4 is an enlarged schematic diagram of a processing section for removing minute protrusions according to another embodiment of the disk finishing apparatus of the present invention. In the embodiment shown in FIG. 3, a contact roller is used to press the abrasive tape, but a material such as a viscoelastic platen 11 may be used instead.As a result of testing under the same conditions as the previous example, The entire surface of the plate could be polished uniformly, and a disk with a homogeneous surface was obtained.

[Effects of the Invention] According to the present invention, the relative speed between the abrasive tape for removing minute protrusions and the disk is constant over the entire surface of both the front and back surfaces of the disk, regardless of the position of the processing point. The effect is uniform over the entire surface of the disk, and the height of the protrusion is reduced evenly. This makes the fine protrusions on the disk surface uniform over the entire surface of the disk, especially for thin-film magnetic disks.

Since it can be reduced with high precision, the most important factor of head flash is eliminated, the head can achieve low flying stability, and the reliability of the disk can be greatly improved.

[Brief explanation of the drawing]

Fig. 1 is a front view of the essential parts of an embodiment of the disc finishing apparatus of the present invention, Fig. 2 is a side view of the essential parts of the same, and Fig. 3 is for explaining the disc finishing method of the present invention. Enlarged schematic diagram of the processing section, No. 4
The figure is an enlarged schematic view of a processing section for removing minute protrusions in another embodiment of the disc finishing apparatus of the present invention, and FIG. 5 is a perspective view showing a conventional protrusion removing apparatus. <Explanation of symbols> 1... Polishing tape, 2... Contact roller, 3...
...Disk, 4 (a, b)...Parallel leaf spring, 5...
Processing head sliding part, 6...Linear scale, 6'...
- Control device, 7... Disc rotation motor, 8... Disc rotation shaft, 9... Abrasive, 10... Fine protrusion, 11...
・Platen, 12... Processing head, W... Dynamic pressure, δ
... Gap between disk surface and polishing tape, h ... Height of protrusion

Claims (1)

[Scope of Claims] 1. A method for finishing a disc in which fine protrusions on the surface of a rotating disc are removed by applying an abrasive tape to the surface of the rotating disc while supplying an abrasive. A disk finishing method characterized in that the relative speed between an abrasive tape and a machining point on a rotating disk that the abrasive tape comes into contact with is constant regardless of the position of the machining point. 2. Attaching a disk in a disk finishing device that removes fine protrusions on the surface of a rotating disk by applying an abrasive tape to the surface of the rotating disk while supplying an abrasive. A disc rotation shaft that can rotate the disc, a disc rotation motor that drives the disc rotation shaft, and a pair that can press and contact contact rollers via abrasive tape to opposing processing points on both sides of the disc. a processing head having a processing unit; a processing head sliding section capable of reciprocating the processing head in the radial direction of the disk; a linear scale for detecting the position of the processing head sliding section; Control capable of controlling the rotation speed of the disc rotation motor so that the relative speed between the polishing tape and the disc at the processing point is constant regardless of the position of the processing point based on a value detected by a scale. A disk finishing device characterized by comprising: