JPS62213957A - Polishing device for disc base board - Google Patents

Abstract

PURPOSE:To prevent generation of unevenness in grinding on a disc base plate by forming the tape pressing surface of a pressure head in a triangle, consisting of an edge member, which stretches along the side of periphery of disc base plate at the grinding tape, and an edge member in the width direction behind the grinding tape in its running direction. CONSTITUTION:The pressure surface 15a of a pressure head 15 is formed approx. in a triangle having a right angle, consisting of an edge member A, which stretches along the side edge situated on the peripheral side of a disc plate 10 for a grinding tape 13, an edge member B, which stretches in the width direction of the grinding tape 13 behind it in its running direction, and an edge member C which crosses aslant the tape 13 from the inner side of the base plate 10 toward its periphery in the direction ahead the tape running. Thus the pressure surface 15a is approx. in a triangle which reduces the width toward the inner side of the disc base plate 10 in its radial direction, so that the peripheral part of the plate 10 with lower circumferential speed has a greater contact surface area, while the inner side with higher circumferential speed has a smaller contact area, resulting in uniform amount of grinding per unit area, which should prevent generation of unevenness in grinding due to the difference of the circumferential speed of the rotating base plate 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application 1] The present invention relates to a disk substrate polishing tool used for smoothing the surface of a disk substrate such as a magnetic disk or an optical disk.

[Prior art 1] A disk substrate, for example a magnetic disk, is manufactured by forming a magnetic film on the surface of a disk substrate made of aluminum or the like by means such as vaporization. Before forming the coating, the surface of the disk substrate is polished to a very smooth surface. Further, even after the magnetic coating is formed, polishing is performed to keep the thickness of the magnetic coating constant, or polishing of the disk substrate is performed before or after the formation of the magnetic coating. A disk substrate polishing device is used for this purpose.

As a polishing apparatus for this disk substrate, the one shown in FIG. 5 has conventionally been used. In the figure, l indicates a disk substrate, and the inner peripheral edge of the disk substrate l is supported by a chuck member 2, and the chuck member 2 is connected to a driving means 3 such as a motor to drive the disk substrate l. By rotationally driving the chuck member 2 by means 3, the disk substrate 1 is rotated. In order to polish the surface of the disk substrate l, an abrasive tape 4 made exclusively of lapping tape is used, and the abrasive tape 4 is pressed against the surface of the disk substrate l by a pressure head 5. 4 and a pressurizing pad 5 for pressing it against the disk substrate l are supported by a reciprocating rotating portion in the radial direction of the disk substrate l by a reciprocating member 6. In order to efficiently polish the disk substrate 1 with the polishing tape 4, the pressing surface of the pressure head 5 against the disk substrate 1 is formed into a rectangular or square shape having a predetermined area. There is.

In order to polish the disk substrate 1 using the polishing apparatus configured as described above, the pressure head 5 is pressed against the surface of the disk substrate l with the polishing tape 4 pressed against the surface of the disk substrate l. The disk substrate 1 is reciprocated in the radial direction by the reciprocating member 6, the abrasive tape 4 is made to run under pressure in a direction perpendicular to the direction of movement of the rad 5, and the disk substrate 1 is rotationally driven by its driving means 3. By doing this, the surface of the disk substrate 1 is polished.

[Problem to be Solved by the Invention 1] Incidentally, in order to efficiently polish the surface of a disk substrate with an abrasive tape, it is necessary to bring the abrasive tape into surface contact with the disk substrate. In the polishing apparatus according to the present invention, the pressing portion of the pressure head 5 against the polishing tape 4 is formed to have a rectangular or square planar shape. Therefore, this pressure head 5
The pressing part contacts the disc substrate 1 over a certain length in the radial direction, or is located on the outer peripheral side and the side edge part located on the inner peripheral side of the disc substrate 1 in the pressing part. There is a difference in circumferential speed between the side edges and this difference in circumferential speed causes a slight difference in the amount of polishing per unit area in the radial direction of the disk substrate l. Therefore, the surface polishing of the disk substrate l However, there was a drawback that uneven polishing occurred, although it was very small. In particular, in recent years, due to demands for increased storage capacity and faster access times, magnetic coatings formed on disk substrates have increasingly become g-films, and such thinner films are becoming more and more popular. In order to deal with this problem, it is necessary to eliminate even the minute polishing unevenness mentioned above.

Moreover, since the moving direction of the pressure head 5 and the running direction of the abrasive tape 4 are perpendicular to each other, the pressing part of the pressure head 5 is placed on a plane having a uniform length in the width direction of the abrasive tape 4. With the conventional abrasive tape 4 having such a shape, there is a risk that the abrasive tape 4 may deviate parallel to the pressure head 5, and if such a deviation occurs, a part of the pressure head 5 or the abrasive tape 4 may deviate. Not only does it come off and promote uneven polishing,
If the pressure is too high, the abrasive tape 4 may come off the pressure head 5, making it impossible to polish the disk substrate 1 with the abrasive tape 4.

The present invention has been made in view of the above points, and aims to prevent the occurrence of uneven polishing due to differences in circumferential speed in the radial direction of a disk substrate, and to apply pressure to an abrasive tape. Another object of the present invention is to provide an ωF polishing device for a disk substrate, which is capable of polishing the disk substrate smoothly and with high precision by pressing the disk substrate in a stable state using a rad.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the disk substrate polishing device according to the present invention has the tape pressing surface of the pressure head on the outer peripheral side of the disk substrate on the polishing tape. The side along
The abrasive tape is characterized in that it is formed into a substantially triangular shape having a widthwise side on the rear side in the running direction of the abrasive tape.

[Operation 1] The present invention is constructed as described above, and this research J'N
To polish a disk substrate using the apparatus, the disk substrate is placed in a state where it is supported by a suitable rotation drive means. Then, an abrasive tape is supplied to one or both surfaces of the disk substrate, and the abrasive tape is pressed against the surface of the disk substrate by the pressing surface of the pressure head of the pressure member. In this state, the disk substrate is rotated, the abrasive tape and the pressure member are reciprocated in the radial direction of the disk substrate by the reciprocating member, and the abrasive tape is run in a direction perpendicular to the moving direction of the pressure member. By doing so, the surface of the disk substrate can be polished.

Since the pressing surface that presses the pressure head against the disk substrate has a substantially triangular shape that becomes narrower on the inside in the radial direction of the disk substrate, the contact area is large on the outer peripheral side of the disk substrate where the circumferential speed is slow. In addition, the inner periphery where the peripheral speed is high comes into contact with a small contact area, which makes the amount of polishing per unit area uniform and prevents the occurrence of uneven polishing due to differences in the rotational peripheral speed of the disk substrate. be done.

In addition, as mentioned above, the pressing surface of the pressure head does not become narrower toward the inside in the radial direction of the disk substrate, and is shaped so that it is comfortable even when facing forward in the running direction of the abrasive tape. The abrasive tape may be displaced parallel to the radial direction of the disk substrate or bent significantly due to the frictional force and ff frictional resistance between the pressurizing head and the abrasive tape, and part or all of the pressing surface of the pressurizing head may be damaged by the abrasive tape. The abrasive tape does not have the inconvenience of coming off, and the abrasive tape remains in stable contact with the pressing surface of the pressure head, thereby reliably preventing the occurrence of uneven polishing or the occurrence of polishing failure itself. become.

[Embodiment 1] Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

First, in FIGS. 1 and 2, IO indicates a disk substrate, and the disk substrate 10 is formed of a member such as aluminum in an annular shape, and each of its front and back surfaces is coated with a magnetic material. It is beginning to form. A polishing device is then used to polish and finish the surface of the disk substrate IO before forming the magnetic coating. This polishing device has a chuck member 11 that supports the inner peripheral edge of the disk substrate IO. By driving, the disk substrate IO can be rotated.

Next, 13 is an abrasive tape made of wrapping tape or the like;
Reference numeral 14 indicates a pressure member, and the pressure member 14 includes a pressure head 15 having a pressure surface 15a that comes into contact with the abrasive tape 13 and presses the abrasive tape 13 against the surface of the disk substrate IO, and the pressure head 15. It consists of a parallel plate spring 16 that generates a sliding torque against the disk substrate 10 of 15, and a support block 17, and the support block 17 is attached to a reciprocating member 18 such as a ball screw device, and the reciprocating member 18 By driving the pressure member 14, the pressure member 14 is reciprocated in the radial direction of the disk substrate 10. Also, the abrasive tape 13 has a feed reel of 1 g.
is supplied from the disk substrate lO by the pressure member 14.
After polishing, the polishing tape 13 is wound onto a take-up reel 20, and the polishing tape 13 is moved perpendicularly to the moving direction of the pressure member 14 by a tape feed roller 21. It is designed so that it can be driven in any direction.

As shown in FIG. 3, the pressing surface 15a of the above-mentioned pressing head 15 presses the abrasive tape 13 against the surface of the disk substrate IO.
A side A along the side edge located on the outer peripheral side of the disk substrate 10 of No. 3, a side B extending in the width direction of the abrasive tape 13 at the rear in the running direction of the abrasive tape 13, and the abrasive tape 1
The polishing tape 13 has a substantially right triangular shape with a side C diagonally across the polishing tape 13 from the inner circumferential side to the outer circumferential side of the disk substrate 10 in the running direction of the disk substrate 10.

This embodiment is constructed as described above, and in order to polish the disk substrate 10 using this polishing device, the disk substrate 10 is fitted into the chuck member 11, and the inner peripheral edge of the disk substrate 10 is Install it in a supported state. Then, the abrasive tape 13 is fed onto the surface of the disk substrate 10, and the abrasive tape 13 is pressed against the surface of the disk substrate IO by the pressure member 14 and the rad 15. In this state, the motor 12 is operated. By doing so, the disk substrate 10 is rotated. At the same time, the reciprocating member 18 is operated to reciprocate the pressure member 14 in the radial direction of the disk substrate 10, and the tape feed roller 21 feeds the abrasive tape 13 from the feed reel 14 side to the take-up reel. By running the polishing tape 13 in a direction perpendicular to the moving direction of the pressure member 15, the surface of the disk substrate 10 can be polished with the polishing tape 13.

Here, the pressing surface 15a that presses the pressure head 15 against the disk substrate 1 (l) has a substantially triangular shape that becomes narrower toward the inside in the radial direction of the disk substrate IO. When the pressing surface 15a
The contact area is the largest on the outer circumference side of the disk substrate IO, and the contact area becomes smaller toward the inner circumference side. Therefore, the contact area on the outer circumferential side of the disk substrate 10, where the circumferential speed is slow, is large, and the contact area on the inner circumferential side, where the circumferential speed is fast, is small. Therefore, the amount of polishing per unit area of the disk substrate 10 is reduced. It becomes possible to make the polishing uniform in the radial direction 9, and it becomes possible to prevent the occurrence of uneven polishing due to a difference in the rotational circumferential speed of the disk substrate 10 in the radial direction.

Further, as described above, the pressing surface 15a of the pressing head 15 has a shape that not only becomes narrower toward the inside in the radial direction of the disk base &to, but also narrows toward the front in the running direction of the abrasive tape. Therefore, polishing tape 13
The frictional force and frictional resistance between the pressing surface 15a and the pressing surface 15a differ depending on the position. That is, when the abrasive tape 13 runs, due to the difference in frictional resistance based on the area difference in the width direction, the abrasive tape 13 moves between the front side and the side A in the running direction, as shown by the arrow X in FIG. The disk substrate 10 is about to be swung so as to rotate around the apex T formed by the side B in the direction of the outer circumference of the disk substrate 10. On the other hand, pressure member 1
4. When reciprocating, there is a difference in the contact area of the pressing surface 15a with the abrasive tape 13 in the length direction. When the pressure member 14 moves from the inner circumferential side toward the outer circumferential side), or in the direction of arrow Z (when the pressure member 14 moves from the outer circumferential side toward the inner circumferential side) shall be. Therefore, when the pressure member 14 moves toward the outer circumference, the deflection in the X direction and the shift in the Y direction cancel each other out, and the abrasive tape 13 remains stable in the direction of movement of the pressure member 14. This will ensure that the vehicle will run in a direction perpendicular to the . Furthermore, when the pressure member 14 moves toward the inner circumferential side, the deflection direction X of the abrasive tape 13 and the deviation direction Z coincide with each other, so that the front side of the abrasive tape 13 in its running direction is shown in FIG. As shown by the dashed-dotted line, it may swing slightly toward the outer periphery. However, even if the polishing tape 13 swings in this direction, the inner peripheral side edge of the disk substrate 10 is
Unless the pressing surface 15a becomes extremely displaced toward the outer periphery (because the abrasive tape 13 is supported by guide rollers at its front and rear sides, such a displacement will not occur). Since the entire body remains in contact with the polishing tape 13, the polishing operation is not hindered.

As described above, even if the abrasive tape 13 is run in a direction perpendicular to the reciprocating direction of the pressure head 15, a portion or all of the pressing surface 15a of the pressure head I5 may come off from one abrasive tape. Therefore, it becomes possible to smoothly and reliably polish the surface of the disk substrate 10 with extremely high precision.

In each of the above-mentioned embodiments, the explanation was given as an apparatus for polishing the disk substrate before forming the magnetic coating, but after the magnetic coating is formed, polishing is performed to make the film thickness constant. Needless to say, it can also be used as a polishing device for polishing disc members such as optical discs. Further, although the configuration is shown in which one side of the disk substrate is polished, if a polishing device is provided on both sides of the disk substrate, both sides can be simultaneously polished.

Furthermore, the oblique side of the pressing surface of the pressing head does not necessarily have to be formed in a straight line, but may be formed in a curved line having a predetermined curvature, such as an arc shape.

[Effects of the Invention] As detailed above, in the disk substrate polishing apparatus according to the present invention, the pressing surface of the pressure head that presses the polishing tape against the disk substrate becomes narrower toward the inside in the radial direction of the disk substrate, and the polishing Since it is formed into a triangular planar shape that becomes narrower toward the front in the running direction of the tape, it is possible to prevent the occurrence of polishing unevenness due to the difference in circumferential speed in the radial direction when the disk substrate rotates. When performing polishing while running the abrasive tape in a direction perpendicular to the reciprocating direction of the pressure head, there is an inconvenience in that a portion of the abrasive tape or its entirety is removed from the pressing surface of the pressure head. It is possible to reliably prevent this, and to smoothly and reliably perform precise and high-precision polishing of the disk substrate.

[Brief explanation of drawings]

FIG. 1 shows the overall configuration of a polishing device (
A. Fig. 2 is a plan view of Fig. 1, Fig. 3 is an enlarged perspective view of the pressure member, Fig. 4 is an explanatory diagram of the operation of the pressure member, and Fig. 5 is an explanatory diagram of the configuration of a conventional polishing device. It is. IO: disk substrate, 13: polishing tape, I4: pressure member, 15: pressure head, 15a: pressure surface, 18: reciprocating member.

Claims (1)

[Claims] The abrasive tape is pressed against the disk substrate by the pressure head of the pressure member, and while the disk substrate is rotated, the pressure head is reciprocated in the radial direction of the disk substrate, and the abrasive tape is pressed against the pressure head of the pressure member. In the polishing device for polishing the surface of the disk substrate by running the polishing tape in a direction perpendicular to the moving direction, the tape pressing surface of the pressure head is defined as a side of the polishing tape along the outer peripheral side of the disk substrate; A polishing device for a disk substrate, characterized in that the polishing device is formed into a substantially triangular shape having a side in the width direction on the rear side in the running direction of the polishing tape.