JPS61261820A - Manufacturing method for magnetic disk media - Google Patents

Abstract

PURPOSE:To obtain a magnetic disk medium having the excellent smoothness and lubricity of a surface by removing the microprojections existing on the surface of a magnetic film formed on a nonmagnetic substrate then forming a protective lubricating layer thereon, polishing the surface and providing ruggedness to the surface by means of a tape having prescribed roughness and abrasive grains. CONSTITUTION:The magnetic film of the medium is first subjected to tape burnishing for removing the microprojections from the surface of said film by using a WA#6000 tape with a polishing device. The protective lubricating layer is then formed by coating a silicon solid lubricating agent thereon by using a solvent and baking the coating and thereafter the surface of the protective lubricating layer is subjected to tape polishing using a WA#6000-8000 tape with the polishing device to remove the projections from the surface of said layer by which the film thickness is adjusted. The lubricating layer is subjected to tape polishing using a WA#4000 tape as final finishing to provide ruggedness on the surface, by which the coefft. of friction and adsorption power on the surface are decreased.

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

The present invention relates to a method of manufacturing a magnetic disk medium used in a contact start/stop (C3S) type magnetic disk device.

[Prior art and its problems]

A magnetic disk medium is used as a recording medium in a magnetic disk device.The magnetic disk is rotated at a predetermined number of rotations, and the magnetic head is floated at predetermined intervals by the airflow generated by the rotation of the magnetic disk. Recording and reproduction are performed on a magnetic disk medium. Many of these popular magnetic disk drives use the contact start/stop method in which the magnetic head comes into contact with the magnetic disk medium when the rotation of the magnetic disk medium starts and stops, and even if the magnetic head floats, the magnetic disk Since the flying distance of the magnetic head is very narrow, less than 1 micron, if there are minute protrusions on the surface of the magnetic layer of the magnetic disk medium, damage will be seen on the medium surface due to contact with the magnetic head. Requires flexibility and lubricity. Conventionally, various methods have been used to improve the smoothness and lubricity of the surface of a magnetic disk medium. Regarding smoothness, burnishing using a sapphire head is mainly used to remove minute protrusions on magnetic disk media, but this method sweeps the entire surface of the magnetic disk, and it takes time to remove minute protrusions. If there are large or strong protrusions on the surface of the magnetic layer, the head will be defeated and the protrusions cannot be removed even if the head hits the magnetic layer. There are many things. Regarding lubricity, since the burnished magnetic disk medium surface is simply coated with a liquid or solid lubricant with good surface lubricity, the presence of protrusions on the underlying surface often has a significant effect. When the surface of a magnetic disk medium is finished using this method, collision between the magnetic head and protrusions during CSS may cause major damage to the magnetic head, and debris generated during the collision may cause damage to the magnetic disk medium itself. A manufacturing process that provides better smoothness and lubricity of the magnetic disk media surface is desired.

[Purpose of the invention]

The purpose of the present invention is to efficiently remove minute protrusions existing on the surface of the magnetic layer of a magnetic disk medium, and to create a surface that has smoothness and lubricity while adjusting the thickness of the surface protective film to an appropriate value. An object of the present invention is to provide a method for manufacturing a magnetic disk that forms a magnetic disk.

[Key points of the invention]

In the manufacturing process of a magnetic disk medium whose surface is coated with a protective lubricant layer, the present invention provides protection after removing only the minute protrusions present on the surface of the magnetic layer formed on the base of the magnetic disk medium using a burnishing tape. After forming a lubricant layer and polishing the protective lubricant layer to a predetermined thickness using a polishing tape if necessary to obtain smoothness,
Using a polishing tape with abrasive grains coarser than 0, the outermost surface of the polishing tape is roughened to reduce the contact sliding area between the magnetic disk medium and the magnetic head, thereby keeping the coefficient of friction small, thereby obtaining even better lubricity. It is something to do.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to the drawings. A nickel phosphorus plating film with a thickness of about 20 microns was formed on an aluminum substrate having an outer diameter of 13 ON φ and an inner diameter of 40 φ, the surface of this film was polished, and then mirror-polished to an average roughness of 0.05 μm or less. After forming 0.05 micron thick Cr# on this nickel phosphorus plating film, 0.05 micron thick Cr# was formed.
A cobalt-nickel magnetic film of 0.05 micron was formed. Next, the surface was processed using a tape polisher having the structure shown in FIG. A magnetic disk medium disc 1 is placed on a turntable 2.
It is chucked and rotated by vacuum force. The contact rubber roller 3 is directly connected to an air cylinder 5 via a roller arm 4, and the air cylinder 5 applies a polishing tape (or a vane tape) via the contact rubber roller 3.
A force is applied between the polishing table (7) 6 and the disc 1, and in reality, a polishing chip 16 of 30M is pressed against the disc 1. In addition, a pressure gauge is attached to the roller arm 4.
It has a mechanism that constantly detects the pressurizing force and maintains it at a constant level. The tape 6 is passed from the brake reel 7 to the tension roller 8.
．． The contact rubber roller 3 is contacted via the guide roller 9, and the guy FC+-ra 9. The tape is wound onto a take-up reel 11 via a tension roller 8, a tape running roller 10, and the surface of the disk 1 is finished when it passes a contact rubber roller 3. The tape is driven by a tape running roller 10, and the running speed can be changed by changing the number of rotations of this tape running roller 10. During machining, grinding fluid is supplied to the machining surface through the outflow pipe 12. Disc 1. The mechanical parts except the turntable 2 are integrated, and the whole can be moved up and down, and when you want to release the pressure,
If this mechanism moves upward, contact rubber roller 3
becomes free prone. Furthermore, this entire mechanism can move (vibrate) parallel to the disk surface during polishing, and by adding this movement during polishing, it is possible to effectively remove minute protrusions on the surface of the medium. Tape burnishing was performed using such a polishing apparatus to remove minute protrusions on the surface of the magnetic film of the medium by using a tape of -AI 16000 and rotating the turntable at 30 rpm. In the tape burnishing process, if the abrasive grain roughness is made rougher than WAI6000, large sliding marks will be created on the surface of the medium, so it is desirable to set the abrasive grain roughness to 116000 or more. However, if the medium is made too thin, the removal of minute protrusions on the surface of the medium becomes inefficient. Next, a silicon-based solid lubricant is applied using a solvent and fired to form a protective lubricant layer.
Tape polishing was performed at 300 rpm using the apparatus shown in the figure, using a tape of WA 16,000 to 8,000, to remove protrusions on the surface of the protective lubricant layer and adjust the film thickness. In this case, since the polishing is on the submicron order, if the load is made lighter, the abrasive grain roughness can be adjusted to the same level as tape burnishing. Of course, polishing is not necessary if the protective lubricant layer has a predetermined thickness by coating. Furthermore, as a final finish - using AI4000 tape, 1100rp
Tape polishing was performed to give the surface an uneven surface. This makes it possible to reduce the coefficient of friction and adsorption force on the surface. For example, the coefficient of friction is 0.3 before and after adding unevenness.
It decreased from ~0.4 to 0.15-0.25. FIGS. 2 and 3 show the results of evaluating the effectiveness of polishing using the output of an AE (acoustic emission) sensor attached to the head. Figure 2 shows A after forming the protective lubricant layer, and Figure 3 shows A after final finishing.
It shows the E sensor output, and when the flying height is insufficient, an output is generated due to the collision between the head and the protrusion on the surface. From this result, it can be seen that the final finish provides good flying performance even at low rotational speeds. However, such a final finishing effect was not observed when microprotrusions on the surface of a magnetic disk medium were removed by a method other than tape burnishing, such as burnishing using a sapphire head.

【Effect of the invention】

According to the present invention, the removal of minute protrusions on the surface of the magnetic layer of a magnetic disk medium, the adjustment of the film thickness according to the necessity of a protective lubricating film covering the surface of the medium, and the formation of irregularities on the outermost surface to reduce the coefficient of friction can all be performed. This is done using a tape polishing device, which makes it possible to reliably remove minute protrusions on the media surface, finely adjust the thickness of the protective lubricant layer, and form an outermost surface with fine irregularities, improving surface smoothness and lubricity. An excellent magnetic disk medium can be obtained.

[Brief explanation of drawings]

FIG. 1 is a front view of a tape polishing apparatus used in an embodiment of the present invention, and FIGS. 2 and 3 are relationship diagrams between the output of an AE sensor attached to a head placed on a rotating magnetic disk medium and rotational speed. FIG. 2 shows the measurement results after the protective lubricant layer was formed in the example of the present invention, and FIG. 3 shows the measurement results after the final finishing. 1: Media disk, 2: Turntable, 3: Contact rubber roller, 5: Air cylinder, 6: Polishing tape (
Vanishing tape). Procedural Amendment Sozi Paku August 13, 1985 1, Case Indication Tokugan Sho, <0 10k,, rδe
3. Relationship with the case of the person making the amendment Applicant 4. Agent Address: 1-1-7 Tanabeshinden, Kawasaki-ku, Kawasaki City Subject of amendment: Detailed explanation of the invention in the specification Contents of the amendment■, Specification On page 4, line 19 of the book, it says IO, 05J [
゛. Correct it to 0.25J.

Claims (1)

[Claims] 1) After removing only the minute protrusions existing on the surface of the magnetic layer formed on the non-magnetic substrate using a vanishing tape, a protective lubricant layer is formed, and then, if necessary, polishing tape is used to remove the predetermined portions of the protective lubricant layer. Sand to thickness, then 60
1. A method for manufacturing a magnetic disk medium, characterized in that the outermost surface is made uneven with a polishing tape having abrasive grains coarser than 0.00.