JPH03116416A - Production of magnetic disk medium - Google Patents

Abstract

PURPOSE:To uniformly remove only fine projections from the surface of a medium at high efficiency by using polishing tapes and specifying the circumferencial speed of the medium to be processed and the pressure given on the tapes for processing. CONSTITUTION:A pair of contact rubber rollers 4 supported by parallel leaf springs 5 are opened or closed on two slide bars 8 by movement of a tapered top 6 attached to an air cylinder 16 and the rollers press polishing tapes on the both sides of a disk 1. The disk medium rotates at the circumferential speed of >=250m/min and is processed by the tapes at the pressure of <=50g/mm<2>. Namely, the tape head structure used here is a light-weight type, in which a driving motor 11 to travel the polishing tape is separated from the contact rubber roller. Thereby, only fine projections on the medium can be uniformly and efficiently removed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method of manufacturing a magnetic disk medium, and particularly to an improvement in a coating film finishing process in the manufacturing process of a magnetic disk medium.

[Conventional technology]

A magnetic disk medium is used as a recording medium in a magnetic disk device.One or more magnetic disks are mounted on a spindle, rotated at a predetermined number of rotations, and a magnetic head is moved against the magnetic disk medium. The magnetic disk is levitated at predetermined intervals by the airflow generated by the rotation of the disk to perform recording and reproduction on the magnetic disk.

In such a magnetic disk device, the flying distance between the magnetic disk and the magnetic head is very narrow, less than 1 micron, and therefore the surface of the magnetic disk medium is required to have highly accurate smoothness.

Recently, contact start/stop (CSS) type magnetic disk drives have become mainstream, in which the magnetic head makes five contacts with the magnetic disk medium when the rotation of the magnetic disk medium starts and stops. In addition, smoothness of the surface of the magnetic disk medium is required.

Currently, the coating surface of such magnetic disk media is finished by the following method.

A conventional surface finishing method for a magnetic disk medium using a polishing tape will be explained with reference to FIGS. 3 and 4.

The central axis of the crowned contact rubber roller 4 is slid back and forth 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, thereby constantly creating a new polishing surface. This is a coating surface finishing method that uses a granular cutting blade to obtain a specified coating thickness and surface smoothness on both sides at the same time.

The surface of the media finished using this method contains microscopic protrusions that cannot be completely removed even in the next burnishing process.
In a magnetic disk device featuring the C8S method,
This causes errors that occur due to large damage to the head, and errors that occur due to fluctuations in the flying height of the head due to collision between the head and these minute protrusions.

An important point in machining to efficiently remove only these minute protrusions is to optimize the circumferential speed when machining the disk medium.

In the above-mentioned finishing method using a polishing tape head, two tape heads are integrated with a contact rubber roller 4, a polishing tape 12, a brake reel 15, a take-up reel 10, and a drive motor 11 for running this polishing tape. Because of the method of processing both sides of the magnetic disk medium 1 using the coil spring 9,
This tape head system becomes heavier.

Therefore, the natural frequency of this tape head system is smaller than the frequency during rotation of the medium, resulting in drawbacks such as insufficient followability and fluctuations in processing pressure.

Figure 1 shows a tape head with a weight of 1.5 kg (current type).
The experimentally determined relationship between the machining peripheral speed and the microprotrusion height (Rp) in the case of is shown.

As is clear from this figure, microprotrusions can be efficiently removed up to a circumferential speed of 250 m/mm, but there is almost no difference even if the circumferential speed is increased beyond that. Furthermore, machining variations may increase due to insufficient followability and machining pressure fluctuations, and machining frictional heat may cause carbonization of the disk medium surface and burnout of the polishing tape. As described above, the current finishing process has various drawbacks. [Object of the Invention] The object of the present invention is to obtain a machining peripheral speed of 250 m that is effective for efficiently removing minute protrusions present on the surface of a magnetic disk medium.
An object of the present invention is to provide an improvement in a light-load type tape head having a fixed frequency that can be followed in order to reduce the variation in the height of micro protrusions due to insufficient followability of the tape head.

[Overview of the invention]

In order to achieve this object, the present invention can be achieved by creating a tape head structure that increases the value of f determined by the equation of the tape head system natural frequency f = 1/2πv' k / m. (m: mass determined by tape head weight W/gravitational acceleration g, k: spring constant) According to the above formula, in order to increase the value of f, reduce the tape head weight W and increase the spring constant of the pressure source. As a means of achieving this, we reduced the width of the polishing tape as much as possible to reduce the weight of the contact rubber roller, and at the same time created a light-load type tape head in which the contact rubber roller part and the drive part for running the polishing tape were separated. This structure improves the tape head system that can follow vibrations during rotation of the magnetic disk medium.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 5 and 6. FIG. 5 shows the tape head structure of the present invention, and FIG. 6 shows an example of the running path of the polishing tape. 1 is a disk of a magnetic disk medium, and the disk is attached to a spindle 7 and a chuck holder 2. It is chucked and rotated.

The contact rubber roller 4 is held by a parallel plate spring 5, which is advantageous for increasing the spring constant, and is opened and closed by the operation of a taber piece 6 provided on an air cylinder 16 on two slide pars 8, and is used for polishing a width of 15 m or more. Tape 12 is applied to both sides of disk 1. The tension spring 9 is provided for returning the contact rubber roller 4 when the pressure is released. A take-up reel 10 for running the polishing tape 12 is fixed to a rotating shaft of a drive motor 11. A motor plate 14 supporting this drive motor 11 is installed independently at a position where the contact rubber roller 4 and the take-up reel 10 are coaxial in the thrust direction.

The polishing tape 12 is applied to the disc 1 from the brake reel 15.
The surface of the disc 1 is finished by passing between the contact rubber roller 4 and the contact rubber roller 4 while being guided by a guide roller 13 and being wound up on a take-up reel 10. Tension roller 17 is connected to contact rubber roller 4 and motor plate 1.
Polishing tape 1 that occurs because 4 is not an integral structure
This is a roller provided to prevent 2 from loosening.

According to this embodiment, the weight of the tape head is only the contact rubber roller 4 fixed to the parallel leaf spring 5, and the weight is approximately 0.
．． It becomes 04 kg.

Therefore, compared to the current type of tape head, the weight W is approximately 1
Below 740, the spring constant k is about twice as high.

The natural frequency of the tape head system can be increased by about 20 times, which has the effect of greatly improving the ability of the tape head system to follow vibrations during rotation of the magnetic disk medium.

〔Effect of the invention〕

If a light load type tape head of 0.04 kg according to the present invention is used, the peripheral speed will be 250 m/ll as shown in Fig. 2.
Since it has a natural frequency that can be sufficiently tracked even in l1n, only the minute protrusions (Rp) can be efficiently and evenly removed.

Therefore, by adding the finishing process according to the present invention after the conventional finishing process, the height of micro protrusions on the medium surface can be controlled to 0.15 μm or less, which has a great effect on the production of magnetic disk media compatible with the C8S method. There is.

[Brief explanation of drawings]

Figure 1 is a diagram showing the relationship between machining peripheral speed and microprotrusion height (Rp), Figure 2 is a diagram showing the relationship between tape head amount and microprotrusion height, and Figure 3 is the current type. 4 is a front view of FIG. 3; FIG. 5 is a plan view of the tape head structure according to the present invention; FIG. 6 is a front view of FIG. 5. . 1... Magnetic disk medium 2... Chuck holder 3... Arm 4... Contact rubber roller 5... Parallel plate 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 number? Closed takeoff 11 Amount (Part 3) Procedural amendment (method) Relationship of the person making the amendment to the matter

Claims (1)

[Claims] 1. In the manufacturing process of a magnetic disk medium, after processing the surface of the magnetic disk medium using a polishing tape or the like, a polishing tape is used to effectively remove only the microprotrusions (R_p) present on the medium surface. peripheral speed of 250 m/min or more, tape processing pressure of 50 g/min.
A method for manufacturing a magnetic disk medium, characterized in that the magnetic disk medium is less than mm^2.