JP2001020100A - Electrolytic working device for disk for magnetic recording medium and working method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To electrolytically etch the surface of a disk extremely precisely with a single disk processing by supplying an electrolytic liquid from a nozzle to the disk while driving to rotate the disk by a spindle. SOLUTION: Both surfaces of the front and the back of the disk 1 are electorlytically etched simultaneously by supporting the disk 1 with the spindle to drive to rotate the disk 1 and pressing an electrolytic liquid holding tape 10 on the surface of the disk 1 at a prescribed load by a pressing roller 11. The pressing roller 11 and the disk 1 are connected to DC power source to be worked as electrodes. The electrolytic liquid is supplied from the nozzle 19 constituting a nozzle unit toward an gap between the electrolytic liquid holding tape 10 and the pressing roller 11 to impregnate the electrolytic liquid holding tape 10 with the electrolytic liquid, the excess electrolytic liquid is retained in a nearly V-shaped groove formed between the electrolytic liquid holding tape 10 and the pressing roller 11 and the electrolytic liquid holding tape 10 is travelled in the direction to be drawn downward from an electrolytic liquid retaining part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording medium disk electrolytic processing apparatus and method for performing a surface treatment with an electrolytic solution in a magnetic recording medium disk manufacturing process.

[0002]

2. Description of the Related Art A disk for a magnetic recording medium used as an information recording medium of a computer or the like is generally constituted by an annular magnetic disk. As a magnetic disk, for example, a base layer made of aluminum alloy or the like is subjected to alumite treatment or non-magnetic plating treatment, etc. Furthermore, there is a configuration in which a protective film is laminated on the surface of the magnetic recording film. As described above, before and after the formation of a plurality of layers, various surface treatments are performed on the surface of a disk (in the following description, a work until a magnetic disk as a final product is manufactured from a substrate is referred to as a disk). Is applied. The surface treatment includes, for example, a polishing step of smoothing the disk surface to achieve a mirror finish, and a texturing step of forming minute grooves on the disk surface to improve the flying characteristics (CSS characteristics) of the magnetic head. It has been widely known that at least a part of these steps is subjected to electrolytic etching, which is a kind of chemical etching, as disclosed in, for example, JP-A-8-171719. Have been.

In the electrolytic etching shown in the prior art, after the texturing performed on the surface of the disk, the disk is washed and then subjected to the electrolytic etching. With this process,
After texture processing, protrusions, burrs, and the like existing on the disk surface are removed so that the disk is finished in a mirror-like state, and protrusions, burrs, and the like can be removed without generating pits and the like on the surface of the disk.

[0004] Generally, the electrolytic etching process is performed by a dipping method. That is, electrolytic etching is performed by injecting an electrolytic solution into the electrolytic bath, setting the disk in the electrolytic bath so that the disk is entirely immersed in the electrolytic bath, and passing a current through the electrolytic bath. In the electrolytic cell, the disk is supported vertically, and the lower side of the disk is generally supported at three points, and a plurality of disks are generally immersed at the same time for processing. When performing an electrolytic etching process, it is necessary to supply a current to the electrolytic solution. However, in the apparatus disclosed in Japanese Patent Application Laid-Open No. 8-171719, a plurality of disks immersed in an electrolytic cell are used. The adjacent disks, that is, the odd-numbered disks and the even-numbered disks function as electrodes having opposite polarities, and the electric current flows between the odd-numbered and even-numbered disks from the AC power supply or the DC power supply. Is configured to flow. In addition, by arranging a large number of disks at narrow intervals in the electrolytic cell, variations in processing between disks are minimized.

In the above-described electrolytic processing apparatus according to the prior art, the so-called batch type dipping process is performed. However, it is not appropriate to perform the disk processing or the processing in a batch type. It may be desirable to do so. For example, in texture processing, using a polishing tape and a slurry liquid in which free abrasive grains composed of diamond powder or the like are dispersed in a solution, the disc is mounted on a spindle, and the polishing tape is pressed while the disc is driven to rotate. Generally, the polishing is carried out by a tape polishing method in which a polishing tape is run by being pressed against a disk surface by a roller with a predetermined pressing force, and a slurry liquid is supplied to the polishing tape. Therefore, it is not desirable to incorporate an electrolytic processing apparatus for performing batch-type processing in the middle of a production line for performing such single-wafer processing of disks from the viewpoint of processing efficiency and simplifying the apparatus configuration. Also, if a large number of disks are immersed in the electrolytic cell at the same time, instead of immersing the disks one by one, single-wafer processing will be performed, but the disk taken out from the spindle is immersed in the tank, It is necessary to perform an operation of pulling out from the next step and sending it out to the next step, so that there are problems that not only the number of steps is increased and the processing takes time, but also that the configuration of the handling means and the like becomes complicated.

With the disk mounted on the spindle,
Japanese Patent Application Laid-Open No. H11-58205 proposes an apparatus which can simultaneously perform texture processing and electrolytic etching processing. The processing device disclosed in this publication drives the disk in a state where the processing tape is pressed against the surface of the disk that is rotationally driven by the spindle with a pressing roller, and at the same time, moves the tape along the disk surface. By supplying a mixed solution of a slurry solution containing abrasive grains from the nozzle to the tape and the disk from the nozzle, the disk can be subjected to texturing and electrolytic etching. It is composed.

[0007]

However, the processing apparatus and processing method disclosed in Japanese Patent Application Laid-Open No. 11-58205 has a very serious problem. That is, the electrolytic solution dropped from the nozzle comes into direct contact with the surface of the disk, and it is extremely difficult to supply the electrolytic solution uniformly over the entire radial direction of the disk. Normal,
The electrolytic solution dropped from the nozzle spreads from the lower position of the nozzle to the inner peripheral side and the outer peripheral side of the disk.However, since the supply amount of the electrolytic solution is always at the lower position of the nozzle, the electrolytic liquid becomes the maximum at that position, Are minimum on the inner peripheral side and the outer peripheral side. Therefore, processing unevenness occurs due to variation in the supply amount of the electrolytic solution on the disk surface. Therefore, if the number of nozzles is increased, the variation in the amount of electrolyte in the radial direction of the disk is suppressed to some extent,
Nevertheless, the amount of the electrolytic solution in contact with the disk cannot be made constant, and it is impossible to prevent the processing accuracy within the same disk surface from being varied after the processing. In particular, in recent years, the flying height of the magnetic head has become extremely small in order to increase the information recording density of the magnetic disk. Therefore, even if there are slight irregularities on the surface of the magnetic disk, a head crash is caused. Inconveniences, such as the possibility of occurrence, occur.

The present invention has been made in view of the above points, and an object of the present invention is to provide a single-wafer processing by supplying an electrolytic solution from a nozzle to a disk while rotating the disk by a spindle. An object of the present invention is to provide an electrolytic processing apparatus that enables high-precision processing when performing electrolytic etching processing.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention comprises a spindle for rotating a disk for a magnetic recording medium and an electrically insulating member permeable to an electrolytic solution. An electrolyte holding member that abuts against the surface of the disk, a pressing member that presses the electrolyte holding member against the disk surface by applying a predetermined load.
A configuration comprising: a nozzle for supplying an electrolytic solution between the electrolytic solution holding member and the pressing member; and a power supply means for flowing an electric current between the disk and the pressing member as electrodes facing each other. The feature is that it is.

Here, the disk for the magnetic recording medium is configured as a magnetic disk, and its substrate can be formed of a metal such as aluminum or copper. Further, in recent years, glass has been used as a substrate for a magnetic disk, but this process cannot be applied to a glass substrate. The electrolyte can be selected from various electrolytes including sulfuric acid, nitric acid, phosphoric acid and the like. The characteristic that the electrolytic solution holding member must have is that it has electrical insulation properties, but it is necessary to further configure the electrolytic solution holding member with good permeability to the electrolytic solution. Therefore, the electrolyte holding member can be formed into various shapes such as a sheet shape and a tape shape having a predetermined thickness. Further, the pressing member may be formed in a block shape, an arc shape, a roller shape or the like. The electrolyte holding member is desirably run along the disk surface. For this purpose, it is constituted as an electrolyte holding tape, and the pressing member is constituted by a pressing roller around which the electrolyte holding tape is wound. The running direction of the electrolytic solution holding tape may be either forward or backward with respect to the rotation direction of the disk, but the tape is run downward.

In order to hold the disk in a vertical state, the spindle is arranged so as to be horizontally oriented. The pressing member is arranged in a direction orthogonal to the rotation center axis of the spindle. Thus, an electrolyte reservoir can be formed above the contact portion between the electrolyte holding member and the pressing member. The electrolyte holding member and the pressing member may be configured to be movable in the radial direction of the disk, but it is desirable that the entire length of the disk extends from the inner peripheral side to the outer peripheral side. The nozzle is for supplying the electrolyte toward the electrolyte reservoir. A single nozzle may be used, but it is desirable to provide a plurality of nozzles at a predetermined pitch in the direction along the surface of the disk, depending on the size from the inner peripheral portion to the outer peripheral portion of the disk. further,
The power supply means may be electrically connected to the disk via the spindle, and the power supply means may be powered from either a DC power supply or an AC power supply. Then, when performing electrolytic etching on the disk,
One side may be processed at a time, but both sides may be processed simultaneously. In the case of simultaneous processing on the front and back surfaces, two sets of the electrolyte holding member, the pressing member, and the nozzle may be provided on both the front and back surfaces of the disk.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. It goes without saying that the present invention is not limited to this embodiment.

First, in FIG. 1, reference numeral 1 denotes a disk to be subjected to a surface treatment by electrolytic etching, and this disk 1 is made of an annular metal substrate and has a spindle 2
And is rotationally driven by the spindle 2. The spindle 2 is supported by a support member 4 via a bearing 3, and a transmission belt 5 to which rotation power from rotation driving means such as a motor (not shown) is transmitted is wound around a base end of the spindle 2. A pulley 6 is attached. Here, the support member 4 is provided in the vertical direction, and the rotation center line of the spindle 2 is oriented in the horizontal direction. And
A clamp member 2a is detachably connected to the tip of the spindle 2, and the disk 1 is held between the tip surface of the spindle 2 and the clamp member 2a.

Thus, as shown in FIG.
Are simultaneously subjected to electrolytic etching. For this purpose, on both front and back sides of the disk 1, electrolytic solution holding tapes 10 and 10 as electrolytic solution holding members and pressing rollers 11 and 11 as pressing members are respectively opposed to each other. Pressing roller 11
Is for pressing the electrolyte holding tape 10 against both the front and back surfaces of the disk 1 with a predetermined load. As shown in FIG. 3, the distance between the inner and outer peripheral edge of the disk 1, i.e. the width B ₁ of the disk 1, the pressing roller 11
The width B ₂ of the electrolytic solution holding tape 10 wound around the pressing roller 11 is sufficiently large, and therefore, the disk 1 is moved from the inner peripheral edge of the disk 1 (the portion clamped by the clamp member 2a) or its vicinity. Width B
It is designed to cover the whole of ₁ . The axis of the pressing roller 11 extends on a horizontal plane including the center axis of the spindle 2 in a direction orthogonal to the center axis of the spindle 2. Therefore, the axis of the pressing roller 11 is also arranged in the horizontal direction. Further, the electrolyte holding tape 10 runs along the surface of the disk 1. Therefore, although not shown, the pressing roller 11 is moved in the running direction of the electrolyte holding tape 10.
On the downstream side of the winding position, a tape running means including a driving roller and a pinch roller is provided.

As is apparent from FIG. 3, a shaft 12 is connected to the pressing roller 11, and the shaft 12 is rotatably mounted on the swing arm 13. Therefore, when the electrolytic solution holding tape 10 is run, the pressing roller 1
1 follows this rotation. The pressing roller 11 is formed of a conductive rubber 11a having a predetermined thickness at least on the outer peripheral side, and the conductive rubber 11a is mounted so as to be attached to the core metal 11b. The swing arm 13 extends upward from a connection portion of the pressing roller 11, and has an upper end connected to a support shaft 14, so that the swing arm 13 performs a pendulum motion about the support shaft 14. By reciprocating by a predetermined angle, the pressing roller 11 can be brought into contact with the disk 1 or separated from the disk 1.

Numerals 15 and 15 denote nozzle units. Each of the nozzle units 15 is provided so as to be supported by a respective swing arm 13 arranged on both sides of the disk 1. The electrolytic solution is supplied from the nozzle unit 15 to between the electrolytic solution holding tape 10 and the pressing roller 11. As shown in FIG. 4, the nozzle unit 15 includes a bracket 16 connected to the swing arm 13, a support block 18 connected to the bracket 16 by a shaft support 17 so as to be adjustable in angle, and a support block 18. 1
And a plurality (three in FIG. 4) of nozzles 19 attached to each of the nozzles 8.
0 is connected. These three nozzles 19 are
The nozzle located at the center of the disk 1 is located at an intermediate position in the width direction of the disk 1, and the nozzles on both the left and right sides are located at the same distance from the center nozzle on the inner peripheral side and the outer peripheral side of the disk 1. .

Further, in FIG. 2, reference numeral 21 denotes a DC power supply which constitutes power supply means. The DC power supply 21 is electrically connected to the disk 1 via the spindle 2;
The disc 1 is also electrically connected to both pressing rollers 11 disposed on both sides of the disc 1. Here, since the pressing roller 11 includes the core metal 11b and the conductive rubber 11a, the DC power supply 21 is finally electrically connected to the conductive rubber 11a. Therefore, when performing the electrolytic etching process, the disk 1 and the two pressing rollers 11 become electrodes facing each other. Then, the two pressing rollers 11, 11 are maintained at the same potential. Specifically, the outer peripheral surface of the pressing roller 11 is
Therefore, a slip ring or the like is provided between the DC power supply 21 and the shaft 12, and finally the conductive rubber 11a
Is supplied with power. As a result, both the front and back surfaces of the disk 1 constituting the electrodes facing each other and the pressing rollers 11,
11, a predetermined voltage is applied via the electrolyte holding tape 10 and the electrolyte impregnated in the electrolyte holding tape 10. Incidentally, the power supply means may be constituted by an AC power supply.

When the disk 1 is subjected to electrolytic etching using the electrolytic processing apparatus having the above-described structure, for example, in the previous step, the disk 1 is polished with a tape, and then its surface is cleaned and cleaned. After drying, the spindle 2 is mounted. Thus, the tape polishing, cleaning, and drying can be performed with the disk 1 mounted on the spindle. Therefore, with this configuration, the disk handling means
The processing can be advanced by sequentially transferring the disks 1 to the spindles provided in the respective stations.

In mounting the disk 1 on the spindle 2, both swing arms 13 are actuated in the opening direction to open the tip of the spindle 2 and to release the clamp member 2 a from the tip of the spindle 2. . In this state, the disc 1 is
Is connected to the spindle 2 and the clamp member 2 a is connected to the spindle 2 to clamp the disk 1. While rotating the spindle 2 to rotate the disk 1, both swing arms 13 are displaced in the direction approaching the disk 1, and the pressing rollers 11
The electrolytic solution holding tape 10 wound around the disk 1 is pressed against the front and back surfaces of the disk 1 so that a predetermined pressing load is applied.

In this state, an electrolytic solution is supplied from each of the three nozzles 19 provided in each of the nozzle units 15, and a predetermined power is applied between the front and back surfaces of the disk 1 and the pressing rollers 11 by a DC power supply 21. By applying a voltage, electrolytic etching is performed on both the front and back surfaces of the disk 1. Here, as the electrolytic solution, for example, an aqueous solution in which at least one kind of acid composed of sulfuric acid, nitric acid, hydrochloric acid, chromic acid or the like has a predetermined concentration can be used.

Thus, 3 constituting the nozzle unit 15
The electrolytic solution supplied from the nozzle 19 is a winding start end position of the electrolytic solution holding tape 10 around the pressing roller 11,
Moreover, the electrolyte holding tape 10 and the pressing roller 11
Supplied to a location between Here, the electrolytic solution holding tape 10 is made of, for example, a nonwoven fabric, is an electrically insulating member, and is formed of a liquid, that is, a tape having good permeability of the electrolytic solution. Moreover, the electrolyte holding tape 10
It is more desirable that a relatively thick material such as about 0.5 to 1 mm be used, and that the material be compressed to reduce the thickness to some extent when a pressing force is applied. The electrolytic solution supplied from the nozzle 19 may be supplied to any position as long as the position is between the electrolytic solution holding tape 10 and the pressing roller 11, but immediately before the winding start end position on the electrolytic solution holding tape 10. When the electrolytic solution is supplied to the electrolyte solution, the electrolytic solution permeates the electrolyte retaining tape 10 more quickly.

As is clear from FIG. 5, the electrolytic solution supplied from the three nozzles 19 is
And the pressing roller 11 collects in a substantially V-shaped groove. In other words, the groove functions as an electrolyte reservoir, and the electrolyte holding tape 10 uniformly impregnates the electrolyte throughout the entire width of the electrolyte reservoir by capillary action. In addition, of the electrolyte supplied to the electrolyte reservoir, the excess not impregnated in the electrolyte holding tape 10 spreads in the length direction of the groove due to the action of surface tension. Then, it is held between the electrolytic solution holding tape 10 and the pressing roller 11. Therefore, the width of the groove is reduced by increasing the radius of the pressing roller 11 and running the electrolytic solution holding tape 10 at a predetermined angle in the direction of winding around the pressing roller 11 from the vertical direction. The depth can be increased. As a result, the electrolyte holding tape 10 is impregnated with the electrolyte uniformly over its entire width until it is substantially saturated. In addition, although both ends of the groove forming the electrolyte reservoir are open, a predetermined amount of the electrolyte is reliably held in the groove by the action of surface tension, and does not overflow from the openings at both ends. Therefore,
In FIG. 5, an electrolytic solution storage portion having a depth indicated by D is formed at a position immediately before contact of the electrolytic solution holding tape 10 with the disk 1, and the electrolytic solution holding tape 10 corresponds to this depth D. The electrolyte is impregnated during traveling for a certain distance, that is, before the electrolyte actually comes into contact with the surface of the disk 1 until the electrolyte is substantially saturated over its entire width.

The electrolyte holding tape 10 impregnated with the electrolyte to a substantially saturated state is pressed against the disk 1 by a pressing roller 11 with a predetermined load. Then, as shown by an arrow in FIG. 5, the feeding direction of the electrolyte holding tape 10 is a direction in which the electrolyte holding tape 10 is drawn downward from the electrolyte reservoir, and as a result, a large amount of the electrolyte is impregnated with the pressing roller 11. Will be supplied during. In addition, the pressing roller 11 presses the electrolyte holding tape 10 against the surface of the disk 1 with a predetermined pressing force, and the pressing force compresses the electrolyte holding tape 10 to a predetermined thickness. Due to the compressing action of the tape 10, the distance between the pressing roller 11 and the disk 1 is kept constant. Then, by successively replenishing an amount of the electrolytic solution corresponding to the amount of the electrolytic solution consumed during the electrolytic etching process from the nozzle 19, a substantially constant amount of the electrolytic solution always stays inside the electrolytic solution reservoir. .

The pressing roller 11 and the disk 1 constitute electrodes, respectively, and a DC power supply 21 applies a predetermined voltage between them. In addition, the gap is separated by the thickness of the electrolyte holding tape 10 therebetween, and the electrolyte is interposed therebetween. As a result,
On the surface of the disk 1, a substantially uniform amount of the electrolytic solution is interposed over the entire length in the radial direction. Then, since the disc 1 rotates, uniform etching is performed so as to cover the entire circumference of the disc 1, and the front and rear surfaces are mirror-finished by the etching action, and extremely high surface precision is maintained. .

Here, the rotating direction of the disk 1 during processing may be the same as the running direction of the electrolytic solution holding tape 10, or may be the opposite direction. However, since the electrolytic processing is performed, it is necessary to increase the contact time of the disk 1 with the electrolytic solution and to increase the contact area of the electrolytic solution holding tape 10 with the surface of the disk 1. For this purpose, the rotation speed of the spindle 2 for rotating the disk 1 is reduced, and the outer diameter of the pressing roller 11 for pressing the electrolyte holding tape 10 against the surface of the disk 1 is increased. Further, the pressing roller 11
Is formed of conductive rubber 11a, the conductive rubber 11a is pressed and deformed to a certain extent, so that the electrolyte holding tape 10 impregnated with the electrolyte forms electrodes facing each other in a wide area. 1 and the pressing roller 11. As a result, the electrolytic etching can be performed more quickly and efficiently.

When the electrolytic etching of the disk 1 is completed, the spindle 2 is replaced with the disk 1. For this purpose, first, the rotation of the spindle 2 is stopped, and the swing arm 13 is operated to separate the electrolytic solution holding tape 10 and the pressing roller 11 from both the front and back surfaces of the disk 1. This operation is performed on the swing arm 1
3 is made to swing away from the disk 1. At this time, the electrolyte holding tape 10 is stopped, and the supply of the electrolyte from the nozzle 19 is shut off. Here, even after the electrolytic etching is completed, a certain amount of electrolyte stays in the electrolyte reservoir between the electrolyte holding tape 10 and the pressing roller 11,
By suppressing the stroke of the swing arm 13 to a necessary minimum and slowing down the swing operation to some extent, the electrolyte in the electrolyte reservoir does not overflow.

After the clamp member 2a is detached from the spindle 2 in the above state, the processed disk 1 is taken out by an appropriate handling means and transferred to the next step. And the disk 1 is clamped by the clamp member 2a. Then, the spindle 2 is operated to rotate the disk 1, and during this time, the swing arm 13 is displaced in a direction approaching the disk 1, and the electrolytic solution holding tape 10 is pressed against the disk 1 by the pressing roller 11. Of the disk 1 can be started.

As a pre-process, the disk 1 is mounted on a spindle to perform texture processing, disc cleaning, and disc drying. In a post-process, the disc 1 is rotated and driven again by the spindle while cleaning and drying again. In the case where an electrolytic etching step is provided between the pre-step and the post-step, the fact that the disk 1 can be mounted on the spindle 2 in this electrolytic etching step means that the disk 1 can be transferred between steps. The configuration is simplified, the operation for transferring the disk 1 is simplified, and the apparatus can be made compact.

[0029]

Since the present invention is constructed as described above, it is possible to perform electrolytic etching by single-wafer processing by supplying an electrolytic solution from a nozzle to a disk while the disk is driven to rotate by a spindle. And the effect that the surface of the disk can be processed with extremely high precision.

[Brief description of the drawings]

FIG. 1 illustrates an embodiment of the present invention, and is an explanatory diagram of a configuration of a spindle that rotationally drives a disk.

FIG. 2 is a schematic configuration diagram of an electrolytic processing apparatus.

FIG. 3 is a sectional view taken along line XX of FIG. 2;

FIG. 4 is a diagram illustrating the configuration of a nozzle unit.

FIG. 5 is an operation explanatory view showing a state where an electrolytic etching process is being performed.

[Explanation of symbols]

 Reference Signs List 1 disc 2 spindle 10 electrolyte retaining tape 11 pressing roller 11a conductive rubber 13 swing arm 15 nozzle unit 19 nozzle 21 DC power supply

Claims (8)

[Claims] 1. A spindle for rotating and driving a disk for a magnetic recording medium, an electric insulating member permeable to an electrolytic solution, and an electrolytic solution holding member in contact with a surface of the disk; A pressing member that applies a predetermined load to press against the disk surface, a nozzle that supplies an electrolytic solution between the electrolytic solution holding member and the pressing member, and an electrode that opposes the disk and the pressing member, An electrolytic processing apparatus for a disk for a magnetic recording medium, comprising a power supply means for flowing a current between these two electrodes. 2. The rotation center axis of the spindle is provided horizontally, and the pressing member is disposed on a horizontal plane including the rotation center axis in a direction orthogonal to the rotation center axis, and 2. A disk for a magnetic recording medium according to claim 1, wherein an electrolytic solution reservoir for storing a predetermined amount of electrolytic solution is formed above the horizontal plane between the member and the electrolytic solution holding member. Electrolytic processing equipment. 3. The electrolyte holding member is constituted by an electrolyte holding tape made of a tape having a predetermined thickness, and the pressing member is constituted by a pressing roller, and the electrolyte holding tape runs downward. 3. The apparatus according to claim 2, wherein the pressing roller is configured to be rotatable following the movement of the electrolyte retaining tape. 4. A structure in which the electrolytic solution holding tape and the pressing roller have a width dimension that abuts at least over a range from the inner peripheral end of the disk or its vicinity to the outer peripheral part. Item 4. An electrolytic processing apparatus for a magnetic recording medium disk according to item 3. 5. The apparatus according to claim 4, wherein a plurality of the nozzles are arranged in a width direction of the electrolytic solution holding tape. 6. The disk is connected to the power supply through the spindle, and a DC or AC current is applied between the spindle and the pressing member from the power supply. An apparatus for electrolytically processing a magnetic recording medium disk according to claim 1. 7. The electrolysis of a disk for a magnetic recording medium according to claim 1, wherein the electrolyte holding member, the pressing member, and the nozzle are provided on both front and back surfaces of the disk. Processing equipment. 8. While the disk for a magnetic recording medium is being driven to rotate, a pressing member is used to press an electrolytic solution holding member having an electrical insulation property and an electrolytic solution on the disk surface with a predetermined load. An electrolytic solution is supplied between the disk and the pressing member, and the electrolytic solution is supplied to electrolytically process the surface of the disk. The electrolytic solution is provided between the electrolytic solution holding member and the pressing member. By supplying the electrolyte solution, the electrolyte solution is retained between the electrolyte solution holding member and the pressing member and the electrolyte solution holding member is impregnated, and the electrolyte solution holding member is impregnated with the electrolyte solution along the surface of the disk. The pressed portion is caused to travel toward the pressing member side, and the electrolytic solution impregnated in the electrolytic solution holding member is brought into contact with the disc by the pressing member. A method for electrolytically processing a disk for a magnetic recording medium, characterized in that: