JPH0558868B2 - - Google Patents

Description

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

[Prior Art] For example, a magnetic disk is used as a disk substrate.
It is manufactured by forming a magnetic coating on the surface of a disk substrate made of aluminum or the like by means such as vapor deposition.In order to uniformly form this magnetic coating, the disk substrate is coated before forming the coating. The surface is polished to an extremely smooth surface. Further, even after the magnetic coating is formed, polishing is performed to keep the thickness of the magnetic coating constant; however, polishing the disk substrate 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, reference numeral 1 denotes a disk substrate, and the inner peripheral edge of the disk substrate 1 is supported by a chuck member 2. The chuck member 2 is connected to a driving means 3 such as a motor to drive the disk. By rotationally driving the chuck member 2 by means 3, the disk substrate 1 is rotated. Then, in order to polish the surface of the disk substrate 1, a polishing tape 4 made of wrapping tape or the like is used.
The abrasive tape 4 is pressed against the surface of the disk substrate 1 by a pressure head 5, and the abrasive tape 4 and the pressure head 5 that presses it against the disk substrate 1 are connected to a reciprocating member 6. Therefore, it is configured to be supported so as to be able to reciprocate in the radial direction of the disk substrate 1. In order to efficiently polish the disk substrate 1 with the polishing tape 4, the disk substrate 1 of the pressure head 5 is
The pressing surface is formed into a rectangular or square shape having a predetermined area.

To polish the disk substrate 1 using the polishing device configured as described above, the polishing tape 4 is pressed against the surface of the disk substrate 1 by the pressure head 5, and then the pressure head 5 is pressed against the surface of the disk substrate 1. 5 as reciprocating member 6
The abrasive tape 4 is caused to reciprocate in the radial direction of the disk substrate 1, and the abrasive tape 4 is made to run in a direction perpendicular to the moving direction of the pressure head 5.
The surface of the disk substrate 1 is polished by rotating it by the driving means 3.

[Problems to be Solved by the Invention] 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. Regarding technical polishing equipment,
A portion of the pressure head 5 that presses the abrasive tape 4 is formed to have a rectangular or square planar shape. Therefore, the pressing portion of the pressing head 5 comes into contact with the disk substrate 1 over a certain length in the radial direction, and the side edge portion of the pressing portion located on the inner peripheral side of the disk substrate 1 A difference in circumferential speed occurs between the disk substrate 1 and the side edge located on the outer circumferential side, 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 1. The surface polishing of the disk substrate 1 had a drawback in that polishing unevenness occurred, although it was minute. In particular, in recent years, the magnetic coating formed on the disk substrate 1 has become thinner and thinner due to demands for increased storage capacity and faster access times. In order to do this, it is necessary to eliminate even the minute polishing unevenness mentioned above.

Also, the moving direction of the pressure head 5 and the abrasive tape 4
Since the running direction of the abrasive tape 4 is perpendicular to the running direction of the abrasive tape 4, the pressing part of the pressure head 5 has a planar shape having a uniform length in the width direction of the abrasive tape 4. There is a risk that the tape 4 may shift parallel to the pressure head 5. If such a shift occurs, a portion of the pressure head 5 may come off from the abrasive tape 4, which not only promotes uneven polishing, but also
In extreme cases, the polishing tape 4 may come off the pressure head 5, making it impossible to polish the disk substrate 1 with the polishing tape 4.

The present invention has been made in view of the above points, and its purpose is to prevent the occurrence of uneven polishing due to the difference in circumferential speed in the radial direction of a disk substrate, and to apply an abrasive tape to a pressure head. To provide a polishing device for a disk substrate, which can press the disk substrate in a stable state and polish the disk substrate smoothly and with high precision.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the disk substrate polishing device according to the present invention has a tape pressing surface of the pressure head in the shape of a substantially right triangle, and the mutual contact between the triangles is One side of the two sides perpendicular to is substantially parallel to the running direction of the abrasive tape and located on the outer peripheral side of the disk substrate, and the other side is on the rear side in the running direction of the abrasive tape, It is characterized by being configured to be located in a direction substantially perpendicular to the running direction.

[Operation] The present invention is constructed as described above, and in order to polish a disk substrate using this polishing apparatus, the disk substrate is placed in a state where it is supported by an appropriate rotational drive means. Then, supply abrasive tape to the surface of one or both sides of this disk substrate,
The abrasive tape is pressed against the surface of the disk substrate by the pressing surface of the pressing head of the pressing 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 moved in a direction perpendicular to the moving direction of the pressure member. The surface of the disk substrate can be polished by running the disk substrate.

Since the pressing surface for pressing the pressure head against the disk substrate has a substantially right triangular shape that becomes narrower on the inside in the radial direction of the disk substrate,
The contact area is large on the outer circumferential side of the disk substrate where the circumferential speed is fast, and the contact area is small on the inner circumferential side where the circumferential speed is slow, so that the amount of polishing per unit area is uniform. , the occurrence of polishing unevenness due to differences in the rotational peripheral speeds of the disk substrates is prevented.

Furthermore, as mentioned above, the pressing surface of the pressure head is shaped not only to become narrower toward the inside in the radial direction of the disk substrate, but also to become narrower toward the front in the running direction of the abrasive tape. Due to the frictional force and frictional resistance between the tape and the pressure head, the abrasive tape may be displaced in parallel to the radial direction of the disk substrate, or may be significantly bent, resulting in damage to a part of the pressing surface of the pressure head or There is no inconvenience that the entire polishing tape comes off, and the polishing tape remains in stable contact with the pressing surface of the pressure head, reliably preventing the occurrence of uneven polishing or the occurrence of polishing failure itself. You will be able to do this.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

First, in FIGS. 1 and 2, reference numeral 10 indicates a disk substrate, and the disk substrate 10 is made of a member such as aluminum formed into an annular shape, and each of its front and back surfaces is coated with a magnetic material. It is starting to form. A polishing device is used to finish polishing the surface of the disk substrate 10 before forming the magnetic coating. As this polishing device, the disk substrate 10
It has a chuck member 11 that supports the inner peripheral edge of the
The chuck member 11 is attached to an output shaft 12a of a motor 12 serving as rotational driving means, and by driving the motor 12 to rotate, the disk substrate 10 can be rotated.

Next, reference numeral 13 indicates an abrasive tape made of wrapping tape or the like, and 14 indicates a pressure member. 15a, a parallel leaf spring 16 that generates a sliding torque of the pressure head 15 with respect to the disk substrate 10, and a support block 1.
7, the support block 17 is attached to a reciprocating member 18 such as a ball screw device, and by driving the reciprocating member 18, the pressurizing member 1
4 is adapted to be reciprocated in the radial direction of the disk substrate 10. In addition, the abrasive tape 13
is supplied from the feed reel 19, pressed against the surface of the disk substrate 10 by the pressure member 14, and after polishing, is wound onto the take-up reel 20, and the polishing The tape 13 is made to run in a direction perpendicular to the moving direction of the pressure member 14 by a tape feed roller 21.

Pressing surface 15a in the aforementioned pressing head 15
As illustrated in FIG. Side B and the abrasive tape 1 at the rear in the running direction of the abrasive tape 13
3, and a side C that diagonally crosses the abrasive tape 13 from the inner circumferential side to the outer circumferential side of the disk substrate 10 in the running direction of the abrasive tape 13. It is becoming.

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 first placed on the chuck member 1.
1, the inner peripheral edge is supported. 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 10 by the pressure head 15 of the pressure member 14. In this state, the motor 12 is turned on. By operating the disk substrate 10, 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 moves 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 10 is
Since it has a substantially triangular shape that becomes narrower on the inside in the radial direction, when it is pressed against the disk substrate 10, the pressing surface 15a is pressed against the disk substrate 10.
The contact area is largest on the outer circumference side, and becomes smaller toward the inner circumference side. Therefore, the contact area on the outer peripheral side of the disk substrate 10 where the circumferential speed is high is large, and the contact area on the inner peripheral side where the peripheral speed is slow is small, and for this reason, 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, and it becomes possible to prevent the occurrence of polishing unevenness 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 substrate 10, but also narrows toward the front in the running direction of the abrasive tape 10. Therefore, the frictional force and frictional resistance between the abrasive tape 13 and the pressing surface 15a differ depending on the position. FIG. 4 shows the operating state when polishing the disk substrate 10 using the polishing tape 13. In the figure, the running direction of the friction tape 13 is indicated by an arrow F, and the rotating direction of the disk substrate 10 is indicated by an arrow R. It is also assumed that the center of rotation of the disk substrate 10 is located on the left side of the paper in the figure. Therefore, the pressing surface 15a of the pressing head 15
Among the three sides composing, two mutually orthogonal sides A,
Of B, the side B is arranged almost parallel to the running direction of the abrasive tape 13 so as to follow the side of the abrasive tape 13 on the outer peripheral side of the disk substrate 10, and the side A is arranged on the rear side in the running direction of the abrasive tape 10. It is located so as to face in the width direction, that is, in a direction substantially perpendicular to the traveling direction. When the abrasive tape 13 is run as described above, the abrasive tape 1
3 is a vertex T formed by side A and side B on the front side in the running direction, as shown by arrow X in Fig. 4.
The disk substrate 10 is about to be swung so as to rotate in the outer circumferential direction about the center. On the other hand, pressure member 1
4 reciprocates, since there is a difference in the contact area of the pressing surface 15a in the length direction of the abrasive tape 13, the abrasive tape 13 moves in the direction of arrow Y in FIG. (when the pressure member 14 moves from the inner circumference side toward the outer circumference side) or in the direction of arrow Z (when the pressure member 14 moves from the outer circumference side toward the inner circumference 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 . In addition, the pressure member 1
When the abrasive tape 13 moves toward the inner circumference, the deflection direction X and the deviation direction Z of the abrasive tape 13 coincide, so that the front side of the abrasive tape 13 in its traveling direction is indicated by the dashed line in FIG. As shown, it may swing slightly toward the outer circumference. however,
Even if the abrasive tape 13 swings in this direction, as long as the inner side edge of the disk substrate 10 is not so extreme as to be displaced from the side C of the pressing surface 15a toward the outer periphery (the abrasive tape 13 is ), the pressing surface 15 is supported by guide rollers, etc., so such displacement does not occur.
Since the entire portion of a is kept in contact with the polishing tape 13, it does not interfere with the polishing operation.

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 15 may come off from the abrasive tape 13. Therefore, it becomes possible to polish the surface of the disk substrate 10 smoothly and reliably 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 other disk members such as optical disks. Further, although a configuration has been shown in which one side of the disk substrate is polished, if polishing devices are provided on both sides of the disk substrate, both sides can be polished simultaneously. 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 arcuate 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 polishing is carried out while the abrasive tape is traveling in a direction perpendicular to the reciprocating direction of the pressure head, it is inconvenient to perform the polishing with a portion of the abrasive tape or its entirety removed from the pressing surface of the pressure head. can be reliably prevented,
It becomes possible to perform precise and high-precision polishing of disk substrates smoothly and reliably.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a polishing apparatus showing an embodiment of the present invention, FIG. 2 is a plan view of FIG. 1, FIG. 3 is an enlarged perspective view of a pressure member, and FIG. 4 is a diagram of a pressure member. FIG. 5 is an explanatory diagram of the structure of a conventional polishing apparatus. 10: disk substrate, 13: polishing tape, 1
4: Pressure member, 15: Pressure head, 15a: Pressure surface, 18: Reciprocating member.

Claims (1)

[Claims] 1. Press the abrasive tape against the disk substrate by the pressure head of the pressure member, and while rotating the disk substrate, move the pressure head back and forth in the radial direction of the disk substrate, and apply the pressure to the abrasive tape. In the device for polishing the surface of the disk substrate by running the tape in a direction perpendicular to the direction of movement of the pressure head, the tape pressing surface of the pressure head has a substantially right triangle shape, and the triangles are at right angles to each other. One of the two sides is substantially parallel to the running direction of the abrasive tape and is located on the outer peripheral side of the disk substrate, and the other side is on the rear side in the running direction of the abrasive tape. , a disk substrate polishing device characterized in that it is configured to be located in a direction substantially perpendicular to the traveling direction.