JP2714316B2 - Method and apparatus for manufacturing magnetic disk medium - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a magnetic disk medium, and more particularly to a finish capable of efficiently removing minute projections present on the surface of a magnetic disk. The present invention relates to a processing method and an apparatus . 2. Description of the Related Art A magnetic disk medium is used as a recording medium of a magnetic disk drive. One or a plurality of magnetic disks are mounted on a spindle and rotated at a predetermined rotation speed. Recording and reproduction are performed on the magnetic disk by floating the magnetic head on the medium at predetermined intervals by an air flow generated by rotation of the magnetic disk. In such a magnetic disk device, the flying distance between the magnetic disk and the magnetic head is very narrow, 1 micron or less, so that the surface of the magnetic disk medium is required to have high-precision smoothness. Recently, at the start and stop of the rotation of the magnetic disk medium, a contact start / stop (CSS) in which the magnetic head makes contact with the magnetic disk medium
The magnetic disk device of the system is mainly used, but in this device, the smoothness of the surface of the magnetic disk medium is further required. At present, the coating film surface of such a magnetic disk medium is finished by the following method. A conventional surface finishing method for a magnetic disk medium using a polishing tape will be described with reference to FIGS. 3 and 4. FIG. The center axis of the crowning-shaped contact rubber roller 4 is reciprocally slid in the radial direction of the disk 1 which is a magnetic disk medium, and the polishing tape 12 interposed between the contact rubber roller 4 and the disk 1 is run, so that a new grinding wheel is always provided. This is a method of finishing both surfaces of the coating film simultaneously to obtain a specified film thickness and surface smoothness with a grain cutting blade. [0003] On the medium surface finished by this method, minute projections which cannot be completely removed even in the subsequent burnishing step are interposed. This is a cause of an error caused by causing a large damage to the head and an error caused by a fluctuation in the head flying height caused by collision of the head with the minute projection. An important point of the processing for efficiently removing only the minute projections is optimization of the peripheral speed when processing the disk medium. In the finishing method using the polishing tape head, two tape heads having an integrated structure of a contact rubber roller 4, a polishing tape 12, a braking reel 15, a take-up reel 10, and a drive motor 11 for running the polishing tape are provided. Is applied to both sides of the magnetic disk medium 1 by the coil spring 9, so that the weight of the tape head system increases. Therefore, since the natural frequency of the tape head system is lower than the frequency of the medium during rotation, there are drawbacks such as insufficient followability and fluctuations in processing pressure. Figure 1 shows the experimentally determined meth relationship for the tape head weight 1.5Kg machining circumferential speed and the minute projection height of the case (current type) (Rp). As is clear from this figure, fine protrusions can be efficiently removed up to a peripheral speed of 250 m / min. However, even if the peripheral speed is further increased, the projections hardly change, but the processing variation due to lack of followability and fluctuation of the processing pressure. Or carbonization of the disk medium surface due to the heat of processing and burning of the polishing tape.
Thus, the current finishing process has various drawbacks.
SUMMARY OF THE INVENTION An object of the present invention is to provide a method and an apparatus for manufacturing a magnetic disk medium capable of efficiently removing minute projections present on the surface of the magnetic disk medium. [0004] A tape-like polishing medium can follow the disk vibration on the surface of a rotating magnetic disk.
And press it with a load that touches the protrusion,
Cutting the projections of the magnetic disk surface while traveling looped polishing media. [0005] The tape-like polishing medium can follow the vibration of the disk
Since the tape-like polishing medium is pressed against the surface of the disk with a load enough to contact the projection , the tape-shaped polishing medium operates so as to follow the vibration (runout) of the disk, and lightly contacts only the projection. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The natural frequency f of a tape head system for polishing the surface of a disk is obtained by the formula of 1 / 2π√k / m (m: weight of tape head W / gravity acceleration g). Mass, k: spring constant). In order to increase the value of f in this equation, it is necessary to reduce the weight W of the tape head and to increase the value of the spring constant k of the pressure source. To this end, the width of the polishing tape is reduced as much as possible. In this case, the weight of the contact rubber roller is reduced, and at the same time, the contact rubber roller portion is separated from the drive unit for running the polishing tape, thereby reducing the weight of the tape head system. That is, the natural frequency of the tape head system is increased. Thus, it is possible to obtain a tape head system that can follow the vibration of the magnetic disk medium during rotation. Hereinafter, a detailed description will be given with reference to FIGS. 5 and 6. FIG. 5 is a tape head structure of the present invention, and FIG.
1 shows an embodiment of a traveling path of a polishing tape. Reference numeral 1 denotes a disk of a magnetic disk medium, and the disk is a spindle 7
And is rotated by the chuck holder 2.
The contact rubber roller 4 is held by a parallel leaf spring 5 which is advantageous for increasing the value of the spring constant k, and a taper piece 6 provided on an air cylinder 16 on two slide bars 8.
Is opened and closed, and a polishing tape 12 having a width of 15 mm or less is pressed against both surfaces of the disc 1. The tension spring 9 is
The contact rubber roller 4 is provided for returning when the pressurization is released. A take-up reel 10 for running the polishing tape 12 is fixed to a rotation shaft of a drive motor 11. The motor plate 14 supporting the drive motor 11 is separated from the contact rubber roller 4 alone and at a position where the positional relationship between the contact rubber roller 4 and the take-up reel 10 does not shift to reduce the weight of the tape head system. Will be installed. The polishing tape 12 is guided by the guide roller 13 between the disc 1 and the contact rubber roller 4 from the braking reel 15 and is wound on the take-up reel 10, thereby finishing the surface of the disc 1. The tension roller 17 is a roller provided to prevent the polishing tape 12 from becoming loose because the contact rubber roller 4 and the motor plate 14 are not integrated. According to the present embodiment, the weight of the tape head is only the contact rubber roller 4 fixed to the parallel leaf spring 5 and is about 0.04 kg. Therefore, the weight W is about 1/4 compared to the current type of tape head.
When the value is 0 or less, the spring constant k is approximately doubled, the natural frequency of the tape head system can be increased to approximately 20 times, and the followability of the tape head system to the vibration during rotation of the magnetic disk medium is greatly improved. Can be. 0.0 according to the invention
If a 4 kg light-weight tape head is used, the second
As shown in the figure, since it has a natural frequency that can sufficiently follow even at a peripheral speed of 250 m / min, the minute protrusion (Rp)
Only can be efficiently and uniformly removed. Therefore, by adding the finishing step according to the present invention after the conventional finishing step, the height of the minute projections existing on the medium surface can be controlled to 0.15 μm or less.
It becomes possible to produce a magnetic disk medium compatible with the CSS method. As described above, according to the present invention, it is possible to cut the fine protrusions present on the surface of the magnetic disk, so that a magnetic disk medium having excellent surface smoothness can be manufactured. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a relationship between a processing peripheral speed and a minute projection height (Rp). FIG. 2 is a tape head amount and a minute projection height. FIG. 3 is a plan view showing a tape head structure of the current type, FIG. 4 is a front view of FIG. 3, and FIG. FIG. 6 is a plan view showing a tape head structure according to the present invention. FIG. 6 is a front view of FIG. [Description of Signs] 1 ... Magnetic disk medium 2 ... Chuck holder 3 ... Arm 4 ... Contact rubber roller 5 ... Parallel leaf spring 6 ... Taper piece 7 ... Spindle 8 ... Slide bar 9 ... Tension spring 10 ... Take-up reel 11 ... Drive motor 12 ... Polishing tape 13 ... Guide roller 14 ... Motor plate 15 ... Brake reel 16 ... Air cylinder 17 ... Tension roller

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Tsutomu Kuze               2880 Kozu, Odawara-shi, Kanagawa Stock Association               Inside Odawara Plant of Hitachi, Ltd.                (56) References JP-A-51-56602 (JP, A)                 JP-A-57-150139 (JP, A)

Claims (1)

(57) [Claims] The tape-shaped polishing medium can follow the vibration of the magnetic disk on the surface of the rotating magnetic disk and is pressed with a processing pressure enough to come into contact with the projections. A method for manufacturing a magnetic disk medium, comprising: shaping a projection. 2. After processing the surface of the magnetic disk using the polishing medium, the processing pressure is such that the tape-shaped polishing medium can follow the vibration of the magnetic disk and contact the protrusions while rotating the magnetic disk. A method for manufacturing a magnetic disk medium, wherein the protrusions on the surface of the magnetic disk are shaved while the tape-shaped polishing medium is running by pressing. 3. Means for holding and rotating the magnetic disk, pressing means capable of following the vibration of the magnetic disk with a tape-shaped polishing medium on the surface of the magnetic disk, and pressing the polishing medium with a processing pressure sufficient to contact the protrusion; and An apparatus for manufacturing a magnetic disk medium, comprising: means for running a tape-shaped polishing medium; and means for moving the tape-shaped polishing medium in a radial direction of the magnetic disk.