JPS61288901A - Method and device for surface-treating substrate for magnetic memory disk - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for machining the surface of a substrate of a magnetic memory disk, in which a cutting tool is guided over a rotating disk with a feed movement corresponding to a desired surface profile. Furthermore, the invention provides a drivable clamping chuck, which clamping chuck has a ring groove connected to a negative pressure source and arranged concentrically for clamping the substrate to be processed. An apparatus for cutting the surface of a substrate of a magnetic memory disk, comprising a front plate and a tool slide for a cutting tool movable perpendicularly to the chuck axis along the chuck axis for tightening; That is, the present invention relates to an apparatus for carrying out the method.

The flatness and surface quality of magnetic memory disks, in which the magnetic heads float above the surface with a spacing of less than 1 μm while the disk rotates for write/sequence operations, has extremely high demands. imposed. These characteristics, which have a large influence on the floating characteristics of a magnetic head, are mostly determined by the support of the magnetic layer, that is, the substrate.

A trouble-free write/continue operation is only guaranteed when the magnetic head is floating quietly.

The substrate used for such magnetic memory disks is
After pretreatment, the surface is milled using a high-precision precision lathe using a diamond machine. At this time, the substrate is clamped to the front plate of the chuck by negative pressure. Often, the disc is Therefore, after removal from the front plate, a slight dishing deformation of the order of magnitude, which is critical for the flying characteristics of the magnetic head, may occur.Measurements have shown that this causes a blanking out of the recording range relative to the line of the disk. or the dent is 1(11)++n to +50-m
The disk diameter was found to be approximately 2 to 5 μm.

It has been found that the electromagnetic values, especially the scanning level, of the convexly curved surface of such a disk are better than those for the concavely curved surface.

Furthermore, the levels were found to be higher than in disks with completely flat sides.

It is therefore an object of the present invention to develop a method and a device for treating the surface of the substrate of a magnetic memory disk, so as to make the electromagnetic values of both sides of the disk equally good and to avoid concave curvature of the surface. There is a particular thing.

According to the invention, this problem is solved in a method for machining the surface of a substrate of a magnetic memory disk, in which the cutting tool is guided on a rotating disk with a feed movement corresponding to the desired surface profile. It is solved in this way. In other words, the adjustable tensioning of the substrate to be processed produces, by contour-adapted tool feed movements, a convexly curved ring surface, which is intended for the recording area, on both sides of the disk.

An embodiment of this method is as follows.

In other words, during attachment, the substrate is elastically deformed, the ring surface to be machined is curved concavely, and the cutting tool is guided radially over the surface, which is then turned over in order to machine the ring surface on the back side. When attaching it, bend the back side of the ring to double the strength.

Another embodiment of this method is as follows. That is, the substrate is attached flat, and the cutting tool is guided along a convex curve on the ring surface to be machined.
At this time, in order to continue machining the back side of the ring, use two tools.
It is guided by a round shape that is twice as strong, and the tightening compensates for the deformation caused by the curvature applied on the chuck.

Yet another embodiment of this method is as follows. That is, the substrate is stretched flat, the cutting tool is guided radially on the surface, and the clamping chuck performs an axial shift in accordance with the feed of the tool, thus forming a convex machining profile. For the subsequent machining of the back ring surface, the clamping moves the chuck with twice the axial stroke, and the clamping compensates for the deformation caused by the curvature exerted on the chuck.

The apparatus for processing the surface of a magnetic memory disk substrate is as follows. In other words, a drivable fastening chuck is provided, which is connected to a negative pressure source and has a front plate with a concentrically arranged ring groove in order to attach the substrate to be processed. In an apparatus for cutting the surface of a substrate of a magnetic memory disk, which is equipped with a "Futami sliding table for a cutting tool movable along the axis of the chuck and perpendicularly thereto,"
The flat edge 031 formed by the ring groove gradually recedes toward the center of the ring-shaped substrate support surface formed by these flat edges on the order of a micrometer range, so that the support surface becomes concave. It's curved.

Another processing device is as follows. That is, a drivable clamping chuck is provided, and the chuck has a front plate connected to a negative pressure source and having one ring groove arranged concentrically in order to attach the substrate to be processed. A tool movement table for the cutting tool is provided which is movable along the axis of the chuck and perpendicularly thereto for tightening.
In an apparatus for cutting the surface of a substrate of a magnetic memory disk, a flat edge formed by a ring groove has a width that gradually decreases toward the center of a ring-shaped substrate support plane formed by these flat edges. Therefore, the supporting force is gradually reduced thereby resulting in a concavely curved deformation of the substrate.

Other processing RiH is as follows. In other words, the drivable clamping chuck is provided with a front plate connected to a negative pressure source and having a concentrically arranged ring groove for clamping the substrate to be processed; In an apparatus for cutting the surface of a magnetic memory disk substrate, which is provided with a tool slide for a cutting tool that is movable along the chuck axis and perpendicular to the chuck axis, the tool is tightened. is coupled to an adjusting element acting along the chuck axis, and the !
J moderation is controllable within the micrometer range.

Another processing device is as follows.

In other words, the drivable tightening is equipped with a chuck,
For this clamping, the chuck is connected to a negative pressure source and has a front plate with concentrically arranged ring grooves for attaching the substrate to be processed, and the clamping is carried out against the clamp along the axis of the chuck. In an apparatus for cutting the surface of a magnetic memory disk substrate, in which a vertically movable tool slide for a cutting tool is provided, the clamping is performed by the chuck, and the clamping is performed by the chuck, which acts along the axis of the chuck. is connected to a node element,
The adjustment angle of this adjustment element can be controlled within the micrometer range.

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

As shown in FIG. 1, by surface treatment according to the present invention, a substrate 1 consisting of a ring surface 2 and a central opening 3 arranged in a recording area and having both sides curved in a five-sided manner is manufactured.

Therefore, the precision rotation involved in machining is tightened using chuck 4 (
(Fig. 12), this tightening is performed by attaching the front plate 5 made of aluminum to the chuck. The front plate has concentrically arranged ring grooves 6, which rings iM are connected via holes 7 and collecting channels 8 to a negative pressure source 9. For clamping, a tool slide 10 with a cutting tool II is usually arranged in front of the chuck, which is therefore only sketched in the figure, and which is used for machining. The clamp is movably supported along and perpendicularly to the chuck axis 12 for a feed movement that corresponds to the desired surface profile of the disc to be processed.

The flat edge 13 formed by the ring groove 6 is
1) The board is held by the negative pressure in the groove of the torque, forming a support surface, and gradually retracts toward the center of the support surface. In the example in Figure 2, the flat edges Edge■
is recessed by 4 μm, so the attached substrate has a slightly concave profile. In this state, the board is placed on the tool sliding table i.

is ground flat by a pure radial feed motion. In order to remove the elastically deformed disk from the front plate 5, the negative pressure is subsequently stopped, thereby loosening the disk.
The shaved ring surface 2 is curved in a five-pointed position. The machining of the back ring surface is carried out in the same way, but the second clamping is carried out with a chuck, and here the flat edge of the front plate is twice that of that on the first front plate in order to compensate for the curvature of the contact surface. It's pulling in twice as hard.

The concave tightening (=I) outer shape of the board attached for cutting can also be obtained in the following manner. That is, if the flat edges 13 formed by the ring groove 6 are made of an elastic material and are formed by these flat edges. The ring is not retracted toward the center of the supporting surface, but the width is reduced. For example, the width of the flat edge ■ and V is 5 mm, and the width of the flat edge ■ and ■ is 41 mm, and the flat edge ■ is 41 mm. 31. If the thickness of the material is reduced, the flat edge will be elastically compressed gradually toward the center of the support surface by the force of the substrate applied by negative pressure, so the disk will become concave. The further processing is then carried out as already described above, with different curvatures of the disc in the first and second machining planes being effected by varying the negative pressure, e.g. In order to make the height of 4μm,
3 (11) torr on the first side, 4 (11) on the second side
Make it tor.

The 5-fold bending of the ring surface 2 can be carried out in another embodiment of the surface treatment according to the invention as follows. That is, the basic 1 is tightened by attaching it to the flat front plate 20 of the chuck 21 and guiding the cutting tool on the rotating disk in a feed movement corresponding to the desired curvature. As is clear from FIG. 3, the holder 15 of the tool 16 added on the tool slide has an adjusting element 17 for the necessary axial movement component, which adjusts the tool is inserted into a cutout 18 which imparts a certain elastic movement capacity to the part of the support that supports it. The motor skills required for each purpose are
This can be controlled by a recess 19 which should be appropriately determined. A quartz crystal is particularly suitable as the adjusting element, which deforms when a voltage is applied, so that the change in length of the quartz corresponding to the desired feed movement can be precisely and reproduced in the micrometer range by means of the voltage control 22. Possible to do. Obviously, other adjusting devices may also be used, provided they can be controlled within the abovementioned dimension ranges, such as electromagnetic, drive or hydraulic adjusting elements.

According to this processing method, one clamping can process both sides of the substrate on the chuck. Because it is the second machining surface, the curve that should be performed with twice the strength is the voltage I11 control part 22.
This is because it can be adjusted by

It is particularly advantageous in this case that the depth preparation of the flat edge can be dispensed with and that the supporting surface of the front panel can be completely flat.

Another way to create a convex curved surface on both sides of the substrate is as follows. In other words, the substrate is attached flat, the cutting tool is linearly guided in the radial direction on the surface, and the chuck is shifted in the axial direction according to the feed of the tool, so that a convex machining profile is formed. Ru. Again, for the reasons mentioned above, an axial stroke twice as large is required when machining the back ring surface.

Therefore, according to the embodiment shown in FIG. There is. For the axial shifting of the unit, the motor casing 28 is connected to a controllable adjustment element 29, as previously described for the axially shiftable tool. Electrical(
In addition to actuated or hydraulic adjusting elements (for example piezoelectric), electromagnetic adjusting drives, for example stepper motors, may also be used.

If an air-bearing spindle is provided, the axial shift of this spindle can be effected by changing the air pressure in the bearing gap on one side only. The air bearing spindle is not shown as it is available as a stock part. At this time, it is sufficient to perform appropriate air control.

[Brief explanation of the drawing]

FIG. 1 is a sectional view along the diameter of a substrate processed according to the invention, and FIG. 2 is a longitudinal sectional view showing a clamping chuck of a precision lathe constructed according to the invention, together with a clamped substrate and a rotary tool. 3 is a longitudinal sectional view of a holder with an FA node element for a rotary tool, and FIG. 4 is a view of a clamping chuck connected to an axially acting adjusting element. 1...Substrate, 2...Ring surface, 3...
...Opening, 4...Tightening with chuck, 5...
...Front plate, 6...Ring groove, 7...
... Hole, 8 ... Collection passage, 9 ... Negative pressure source, 10 ... Tool sliding table, 11 ... Tool, 12 ... ...Tighten on the chuck axis, 13...
...Flat edge, 14...Tool sliding table, 1G...
...Tool, 17...-t! ! 1tRf element,
20...Front plate, 21...Chuck for tightening, 24...Chuck for tightening, 29...
...Adjustment element patent applicant Passfachchengesellschaft representative Patent attorney 1) Osamu Kuro, Figure 1, Figure 4

Claims (8)

[Claims] (1) A method of machining the surface of a substrate of a magnetic memory disk, in which the cutting tool is guided on a rotating disk with a feed movement corresponding to the desired surface profile, in which the adjustable surface of the substrate to be machined A method for surface treatment of a substrate of a magnetic memory disk, characterized by manufacturing a convexly curved ring surface in a recording area on both sides of the disk by a tool feeding movement in accordance with the attachment outer shape. (2) When pasting, the substrate is elastically deformed, the ring surface to be machined is curved concavely, and the cutting tool is guided in the radial direction on the surface. 2. The method according to claim 1, wherein the back side ring surface is bent twice as hard when the ring is turned over and pasted. (3) The substrate is attached flat and the cutting tool is guided along a convex curve on the ring surface to be machined, in order to subsequently machine the back side of the ring.
2. A method as claimed in claim 1, in which the guide is guided with a double degree of curvature to compensate for the deformations caused by the curvature stretched over the clamping chuck. (4) The substrate is stretched flat, the cutting tool is guided radially on the surface, and the clamping chuck performs an axial shift in accordance with the feed of the tool, thus forming a convex machining profile, during which 2. A method as claimed in claim 1, in which the clamping chuck is moved with twice the axial stroke for subsequent machining of the back ring surface, compensating for the deformations caused by the curvature exerted on the clamping chuck. (5) A drivable clamping chuck (4) is provided, which clamping chuck is connected to a negative pressure source (9) and has a concentric ring groove for clamping the substrate (1) to be processed. (6) and a tool slide (10) for a cutting tool (11) movable along and perpendicularly to the clamping chuck axis (12). , an apparatus for cutting the surface of a substrate of a magnetic memory disk, in which a flat edge (13) formed by a ring groove (6) is directed toward the center of a ring-shaped substrate support surface formed by these flat edges, Apparatus for the surface treatment of a substrate of a magnetic memory disk, characterized in that it is gradually set back on the order of dimensions in the micrometer range, so that the supporting surface is concavely curved. (6) A drivable clamping chuck (4) is provided, which clamping chuck is connected to a negative pressure source (9) and has a concentric ring groove for clamping the substrate (1) to be processed. (6) and a tool slide (10) for a cutting tool (11) movable along and perpendicularly to the clamping chuck axis (12). , in an apparatus for cutting the surface of a substrate of a magnetic memory disk, a flat edge (13) formed by a ring groove (6) gradually moves toward the center of a ring-shaped substrate support surface formed by these flat edges. Apparatus for the surface treatment of a substrate of a magnetic memory disk, characterized in that it has a width that decreases in width, thereby resulting in a gradual reduction in the supporting force, resulting in a concavely curved deformation of the substrate. (7) A drivable clamping chuck (21) is provided, which clamping chuck is connected to a negative pressure source and has a concentric ring groove for clamping the substrate (1) to be processed. The surface of the substrate of the magnetic memory disk, comprising a front plate (20) and provided with a tool slide (14) for a cutting tool (16) movable along the clamping chuck axis and perpendicularly thereto; The tool (16) is coupled to an adjusting element (17) acting along the axis of the clamping chuck, the adjustment amount of which is controllable in the micrometer range. An apparatus for surface treatment of a magnetic memory disk substrate, characterized by: (8) A drivable clamping chuck is provided, which clamps the substrate to be processed.
A magnetic machine comprising a front plate connected to a negative pressure source and having a concentrically arranged ring groove, and provided with a tool slide for a cutting tool movable along and perpendicularly to the axis of the clamping chuck. In an apparatus for cutting the surface of a substrate of a memory disk, a clamping chuck (24) is coupled to an adjusting element (29) acting along the clamping chuck axis, the adjustment amount of which is within the micrometer range. 1. An apparatus for surface treatment of a magnetic memory disk substrate, characterized in that it can be controlled by: