JPH0630154B2 - Magnetic disk coating device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a magnetic material coating apparatus for forming a magnetic recording film on the surface of a disk substrate in a magnetic disk manufacturing process.

[Prior Art] In a magnetic disk, a surface of a disk substrate formed by annularly forming a plate body of aluminum or the like is polished and smoothed, and then a magnetic recording film is formed on the surface. It is manufactured by applying a liquid, and the method for forming this magnetic recording film is as follows.While the disk substrate is rotating at a high speed, a magnetic material applying liquid is applied to a position near the inner peripheral edge by the applying liquid supply nozzle. It is known that the magnetic material coating solution is supplied to the magnetic material so that the magnetic material coating solution is made into a thin film while advancing toward the outer peripheral surface side by the action of the centrifugal force generated by the rotation of the substrate. The supporting means for rotating the disk substrate at a high speed in this way is designed to prevent damage to the surface of the disk substrate and to ensure that the outer peripheral edge portion of the coating solution is well drained. It is necessary to engage with the peripheral portion.

Thus, as a supporting means for supporting the inner peripheral edge of the disk substrate and rotating it at a high speed, for example, a clamp unit including male and female clamp members that come into contact with front and back surfaces of the inner peripheral edge of the substrate. By using the above, by inserting the other clamp member into the one clamp member in a state where the substrate is fitted to the one clamp member, the substrate is sandwiched between the clamp members,
Using a plurality of chuck pieces with tapered surfaces facing each other,
The chuck pieces are arranged to be displaced in the radial direction of the substrate, and when chucking the substrate, the chuck pieces are expanded outward in the radial direction so that the taper surfaces of the chuck pieces contact the corners of the inner peripheral edge of the substrate. It has been conventionally used that the chucking is performed by bringing them into contact with each other.

[Problems to be Solved by the Invention] In order to increase the recording capacity of the magnetic disk and to speed up the access time, the magnetic recording film should be thin and the film thickness should be uniform. Need to be
The thinning of the recording film and the uniformization of the film thickness are achieved by controlling the supply amount of the magnetic material coating liquid and rotating the disk substrate at a high speed.

By the way, in the supporting means of the disc member having the above-mentioned structure, when the disc substrate is rotated, the disc member is rotated by the protrusion when the clamp member or the chuck piece projects from the surface of the disc substrate. The air flow generated on the magnetic material coated surface of the substrate is disturbed, and this turbulent flow affects the film thickness of the coating film of the magnetic material coating liquid, and it is not possible to form a recording film having a uniform film thickness. It will be. In particular, this turbulent flow becomes large when the disc substrate is rotated at a high speed. Therefore, in order to promote thinning, when the disc substrate is rotated at a high speed,
This turbulent flow has a drawback that the unevenness of the film thickness of the magnetic recording film is significantly increased.

The present invention has been made in view of the above points, and an object thereof is to suppress the generation of turbulent flow, which has an influence on the film thickness management when forming a magnetic recording film, to a minimum source. By doing so, it is an object of the present invention to provide a magnetic material coating device for a magnetic disk capable of forming a magnetic recording film having a uniform and extremely thin thickness.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides an annular flange portion continuous with the tip of a cylindrical rotary shaft having an open tip, and the flange portion is used to At least three clamp claws are formed on the flange portion by forming slit grooves up to the intermediate part of the main shaft, and each clamp claw has a width substantially the same as the inner peripheral surface of the disk substrate. A clamp surface having the same is formed, and the clamp claws are deformed on the main shaft between a clamp position where the clamp surface is in pressure contact with the inner peripheral surface of the substrate and a substrate mounting position where the substrate can be inserted. The feature is that the actuating member to be displaced is engaged and provided.

[Operation] Then, the clamp claws are positioned inward in the radial direction, and the clamp claws are held in a state where the inner peripheral portion of the disk substrate can be fitted, that is, at the substrate mounting position.

Therefore, the disc substrate is taken out from the previous step by holding the outer peripheral edge portion by an appropriate handling means, for example, and conveyed to the working unit for applying the magnetic substance, and the disc substrate is fitted into the clamp claw. To combine. After that, the actuating member is actuated to expand the clamp claw of the main shaft and displace it to the clamp position where it is displaced radially outward, and its clamp surface is pressed against the inner peripheral surface of the disk substrate. By doing so, the disc substrate can be clamped by the clamp claws.

Since the width of the clamp surface of the clamp claw is almost the same as the plate thickness of the disc substrate, the clamp claw at the time of this clamping forms the same plane as the surface of the disc substrate. Even when the substrate is rotated, the air flow generated on the surface of the substrate becomes a flow without turbulence from the central portion toward the outer peripheral side. Therefore, if the magnetic material coating liquid is supplied to the position near the inner peripheral edge of the disk substrate by the coating liquid supply nozzle, the magnetic material coating liquid is smoothly affected by the centrifugal force without being affected by the air flow. It becomes possible to form a magnetic recording film having a uniform film thickness on the disk substrate while thinning while advancing toward the side. Since this centrifugal force increases with an increase in the number of rotations of the disk substrate, the disk substrate can be rotated at a high speed in order to make the film thickness extremely thin. In the above, since the turbulence does not occur in the air flow, there is no possibility that the magnetic recording film becomes non-uniform even if the rotation speed of the disk substrate is increased.

Embodiments Embodiments of the present invention will be described in detail below with reference to the drawings.

1 to 3 show a first embodiment of the present invention, in which 1 denotes a disk substrate made of an annular plate member such as aluminum, and the disk substrate 1 is a clamp device 2
The inner peripheral surface of the disk is rotated at a high speed while being clamped, and during this period, the coating liquid supply nozzle 3 supplies the coating liquid of the magnetic material to the surface of the disk substrate 1 so that the magnetic recording film can be formed. Has become.

The clamp device 2 has a main shaft 4 formed in a hollow cylindrical shape and made of a metal material having a spring property, and the main shaft 4 is rotated at a high speed by a rotation driving means 5 such as an electric motor. An annular flange portion 6 having a thickness substantially the same as the plate thickness of the disk substrate 1 is continuously provided at the tip of the main shaft 4 so as to project outward in the radial direction. From the middle to the intermediate portion of the main spindle 4, there is formed a slit crack groove 6, 7, ...
... and clamp claws 9, 9 on the side of the flange portion 6 are formed. The outer peripheral surface of each of the clamp claws 9 is a clamp surface 9a, and the clamp surface 9a is in contact with the inner peripheral surface of the disk substrate 1 as much as possible. It has a curved surface shape that is similar to the inner peripheral surface of the substrate 1.

The above-mentioned clamp surface 9a of the clamp claw 9 is at a board mounting position slightly inside the inner peripheral surface of the disk board 1 when the flap piece 8 on the main shaft 4 is in a free state, and the flap piece 8a. When the clamp claw 9 is bent outward in the radial direction by displacing it, the clamp surface 9a is displaced to a clamp position where it can be pressed against the inner peripheral surface of the disk substrate 1. . In order to expand and deform the flap piece 8 in this manner, the main shaft 4
A frustoconical wedge member 10 is mounted as an operating member on the inside of the, and the wedge member 10 is attached to the inner surface of the flap portion 8.
A sliding portion 8a having a tapered surface that is in sliding contact with is formed. An operating rod 10a is connected to the wedge member 10, and the operating rod 10a is connected to a drive member 11 including a cylinder for moving the operating rod 10a along the axis of the main shaft 4 in the arrow direction in FIG. It is connected. Further, the driving member 11 and the operating rod 10
A bearing 12 is interposed between the operating rod 10a and a so that the operating rod 10a can rotate freely. The board 10 can be displaced from the board mounting position to the clamp position, and the operating rod 10a can be rotated following the spindle 4. Further, it is possible to prevent the magnetic substance coating liquid or the like from adhering to the sliding contact portion between the wedge member 10 and the sliding portion 8a of the flap portion piece 8, and to attach abrasion powder or the like to the disc substrate 1 due to the sliding contact therebetween. In order to prevent this from happening and to flatten the tip end surface of the clamp device 2, the slit groove 5 forming portion and the tip end opening portion of the main shaft 4 are filled with an elastic sealing material 13 made of silicon rubber or the like. ing.

Further, reference numeral 14 in the figure denotes a positioning member fitted to the main shaft 4, and the positioning member 14 has a hollow cylindrical shaft portion 14a.
It is formed by continuously connecting an annular portion 14b protruding outward in the radial direction to the tip of the above, so that the main shaft 4 of the clamp device 2 can be moved in the axial direction. When the disc substrate 1 is inserted into the clamp claw 9, the annular portion 14b is brought into contact with the back surface of the clamp claw 9 so that the disc substrate 1 comes into contact with the inner peripheral portion of the disc substrate 1 and the disc substrate 1 The inner peripheral surface of the clamp claw 1 can be reliably positioned at a position facing the clamp surface 9a of the clamp claw 9.

Reference numeral 15 in the drawing is a handler for chucking the outer peripheral portion of the disk substrate 1 and transferring the disk substrate 1 from the previous step to the magnetic material coating step.

The present embodiment is configured as described above, and its operation will be described next.

First, the drive member 11 is projected so that the wedge member 10 is clamped by the clamp claw 9.
Is held in a state in which an external force is not applied to the clamp substrate 9 and the clamp surface 9a of the clamp claw 9 is located slightly inside the inner peripheral surface of the disc substrate 1, and in this state, the disc substrate 1 is held by the handler 15. Chuck and move toward the clamp device 2. Then, the disc substrate 1 is fitted into the clamp claw 9 of the clamp device 2, but when the disc substrate 1 is fitted into the clamp claw 9, the clamp claw 9 and the disc substrate 1 should not be brought into contact with each other. In order to ensure that the disk substrate 1 has a predetermined gap between the disk substrate 1 and the clamp claw 9, the handler 15 always detects the center position of the clamp device 2 by a sensor (not shown). 1 is transferred to the clamp device 2. At the time of this transfer, since the flange portion 8a of the positioning member 10 is in contact with the back surface of the clamp claw of the clamp device 2, the axial positioning of the disk substrate 1 in the clamp device 2 can be reliably performed. .

When the wedge member 10 is displaced in the direction of the arrow in FIG. 1 after the disc substrate 1 is loosely fitted to the clamp claw 9 of the clamp device 2 in this way, the wedge member 10 is moved to the inner surface of the flap portion 8. By moving along the formed sliding portion 8a, the flap portion 8 is bent while being deformed by the elastic sealing material 13 in a direction of being curved outward in the radial direction of the main shaft 4. As a result, the clamp claw 9 expands and comes into contact with the inner peripheral surface of the disk substrate 1. Then, when the wedge member 10 is further moved from this state and pressed in the direction of expanding the clamp claw 9, the clamp surface 9a of the clamp claw 9 is pressed.
Is pressed against the inner peripheral surface of the disk substrate 1, and at this time, the flap portion piece 8 having a spring property is bent and exerts a clamping force according to the amount of the bending amount. Therefore, if the amount of movement of the wedge member 10 by the drive member 12 is adjusted, the clamping force of the disc substrate 1 by the clamp claw 9 can be adjusted, and an appropriate clamping force can be obtained according to the rotation speed of the disc substrate 1. It can be exerted, and there is no possibility that vibration or the like will occur in the plate thickness direction during this rotation. Further, in this case, by setting the clamp surface 6a to have a diameter slightly smaller than the inner peripheral edge portion of the disc substrate 1 when the flap portion piece 8 is in the unclamped state in the free state, The flap 8 can exert a large clamping force with a small amount of displacement during clamping.

As described above, the clamp claw 9 is used to hold the disk substrate 1
After clamping the substrate, the handler 11 is separated from the disk substrate 1 and the positioning member 14 is retracted. In this state, the spindle 4 is rotated by the rotation driving means 5, and the coating liquid supply nozzle 3 applies the magnetic material. When the liquid is supplied so as to be jetted at a predetermined pressure, the coating liquid advances from the inner peripheral edge side of the disk substrate 1 toward the outer peripheral edge portion by the action of the centrifugal force due to the rotation of the disk substrate 1,
During this period, the film is thinned. Then, the coating liquid that has reached the outer peripheral portion is scattered as it is due to the action of the centrifugal force described above.

Thus, since the clamp claw 9 in the clamp device 2 is formed in a flat state having substantially the same thickness as the disc substrate 1, the air flow generated on the surface of the disc substrate 1 due to the rotation of the disc substrate 1 is generated. Since there is no possibility of being disturbed and there is a constant and stable flow from the central portion to the outer peripheral side along the surface of the disk substrate 1, when the coating liquid of the magnetic material is supplied to the disk substrate 1 and the disk substrate 1 There is no inconvenience that the film thickness becomes uneven due to the influence of the air flow when the film 1 is diffused from the inner peripheral side toward the outer peripheral side while being diffused. Since the magnetic substance can be applied in a state where there is no possibility of turbulence of the air flow in this way, the disc substrate 1 is rotated at a high speed to form an extremely thin and uniform magnetic recording film. As a result, the recording capacity can be improved and the access time can be shortened.

It should be noted that when the magnetic material is applied, the application liquid may flow into the inner peripheral side of the disk substrate 1, but the wedge member 9 and the sliding portion 8a of the flap portion 8 are sealed by the elastic sealing material 9. As a result, foreign matter on these sliding contact surfaces is mixed, and conversely, dust or the like generated during the sliding operation between the wedge member 10 and the sliding portion 8a adheres to the disk substrate 1. That's not it.

When the formation of the magnetic recording film on the disk substrate 1 is completed as described above, it is conveyed to the next step by an appropriate handler that supports the outer peripheral surface of the disk substrate 1, and at this time, the wedge member 9 is moved to the above-mentioned state. By displacing the flap piece 8 in the direction opposite to the operating direction, the flap portion 8 returns to the free state due to its spring property, and the clamp claw 9 is displaced to the unclamped state.

In the above-mentioned embodiment, the structure in which the main shaft 4 is provided with the six flap pieces is shown, but this is based on the convenience of work and supports three points on the inner circumference of the disk substrate 1. In order to make it possible, at least three may be provided. Further, when the disc substrate 1 is fitted to the clamp piece 8, the positioning in the plate thickness direction is as follows.
As shown in FIG. 4, the clamp claw 9'is attached to the rising step wall 9
It is also possible to form a'and form the clamping surface 9b 'on the tip side of the step wall 9a'. Further, although the frusto-conical wedge member is used as the actuating member, a wedge member having, for example, a spherical shape may be used, and the flap member may be formed in a ring shape to be fitted to the main shaft 4. In a free state, the piece may be set to a clamp position for clamping the disc substrate 1, and the flap-shaped piece may be displaced inward in the radial direction by the ring-shaped actuating member to be displaced to the substrate mounting position.

[Effects of the Invention] As described in detail above, the present invention uses a clamping device that clamps the inner peripheral edge of a disk substrate in a state where the surface of the disk substrate is substantially flush with the magnetic material application surface of the disk substrate. Since the disk substrate is clamped and the magnetic material is applied while rotating the disk substrate, it is possible to generate turbulence in the air flow generated on the surface of the magnetic material during the coating operation. Thus, it is possible to form an extremely thin magnetic recording film having a uniform thickness.

[Brief description of drawings]

1 to 3 show a first embodiment of the present invention. FIG. 1 is a sectional view of a clamp device, FIG. 2 is a perspective view thereof, FIG. 3 is a plan view, and FIG. It is sectional drawing of the clamp apparatus which shows the 2nd Example of this invention. 1: disk substrate, 2: clamp device, 3: coating liquid supply nozzle, 4: spindle, 6: slit groove, 8: flap part piece, 8a: sliding part, 9: clamp claw, 9a: clamp surface, 1
0: wedge member

Claims (2)

[Claims] 1. A magnetic recording film is formed on the surface of a substrate by supplying a magnetic material coating liquid from a coating liquid supply nozzle to the surface of the substrate while the disk substrate is rotated at a high speed. In a magnetic material coating device for a disk, an annular flange portion is continuously provided at the tip of a cylindrical rotary shaft having an open tip, and a slit groove is formed in a portion from the flange portion to an intermediate portion of the main shaft. Thereby forming at least three clamp claws on the flange portion, each clamp claw having a clamp surface having a width substantially the same as the inner peripheral surface of the disk substrate, and the main shaft having the respective clamp claws. A structure in which an actuating member that deforms the claw and displaces the clamp surface between a clamp position where the clamp surface is in pressure contact with the inner peripheral surface of the substrate and a substrate mounting position where the substrate can be inserted is provided. Magnetic coating device of a magnetic disk, characterized in that the. 2. A magnetic body for a magnetic disk according to claim 1, wherein an elastic seal member is filled in a gap between the clamp claws and an open end portion of the main shaft. Coating device.