JP2002346902A - Polishing device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing device for making finishing accuracy of a workpiece high accurate and a polishing method using the device. SOLUTION: This device is constituted of a pair of lapping tape supplying/ winding means 64 and 65 for supplying a lapping tape 70 from a supply side and winding the supplied lapping tape 70, a lapping tape holding base 77 which is arranged between the pair of the lapping tape supplying/winding means 64 and 65 and finishes a lapping tape traveling surface with high accuracy, a lapping tape traveling and holding mechanism A for imparting tension to the lapping tape laid on the lapping tape holding base 77, a moving mechanism B holding the traveling and holding mechanism A and moving in a direction crossing the traveling direction of the lapping tape, and slide mechanisms 81, 82, 83, 84 and 85 having rotation means 78 and 80 for rotating the workpiece 44 in a state of the workpiece 44 abutted on the lapping tape 70 within the traveling and holding mechanism A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing apparatus for precisely finishing a small-diameter disc having a hole, which is a molded part formed by processing means, and a polishing method using the same.

[0002]

2. Description of the Related Art In the IT revolution, in HDDs (hard disk drives), which are the favorite of IT data storage, there is a great demand for an increase in storage capacity. That is,
The recording density of HDDs has doubled in recent years, and the number of tracks per inch (TPI) is 25,000 TPI in the current notebook personal computer. In the future, with the demand for higher density, it is necessary to further increase the recording density on a disc of a limited size.

[0003] By the way, the index for increasing the recording density is the TPI. In the currently mainstream ball bearing, the rolling element and the inner ring or the outer ring rotate while making point contact with each other.
The rotation of the motor through the bearing causes a relative deviation "NRRO" (asynchronous deviation, hereinafter referred to as NRRO) from a perfect circle, and the limit of TPI is beginning to be seen. If the NRRO is large, a deviation occurs from the track width of the disk (off-track), and a phenomenon such as generation of noise in a signal or inability to read data occurs.

On the other hand, NRRO is 1/10 of the track width.
Must be kept below. For example, 30000TP
For a track width of I, it is 0.8 μm and therefore NR
RO needs to be 0.08 μm or less. If a fluid bearing is used, NRRO can be suppressed to 0.04 μm or less, but a ball bearing cannot be used at about 0.08 μm. Therefore, fluid bearings are attracting attention instead of ball bearings, and the development competition of HDD motors using such fluid bearings has been spurred.

Further, with the miniaturization of devices, HDDs as means for recording information have been further miniaturized and thinned. The rotary drive, which is the heart of this type of device, has both a bearing and a motor built into the drive hub,
Further, by mounting a plurality of recording / reproducing disks on the outer periphery of the drive hub, the size of the apparatus is reduced and the storage capacity is increased. Further, in order to increase the recording density, it is necessary to dramatically improve the accuracy of the rotating spindle.

Here, an example of a motor using a fluid bearing will be described. A motor used to rotationally drive a recording medium such as a hard disk incorporated in the recording medium driving device, for the reason described above, to rotationally support the shaft and the sleeve member relatively, A motor using a hydrodynamic bearing utilizing the fluid pressure of a lubricating fluid interposed between the two has been used, and one example thereof will be described in detail below with reference to FIG.

FIG. 17 is a longitudinal sectional view showing the structure of a generally used hydrodynamic bearing motor.

Referring to FIG. 17, a shaft holding cylinder 2 of a hydrodynamic bearing motor 1 has a large-diameter cylindrical base 2a having a lower outer peripheral portion fitted into a circular fitting hole 3a of a base 3 of a recording medium drive. The annular plate 2 is fixed to the upper end of the base 2a.
A small-diameter cylindrical sleeve portion 2c is provided coaxially through the center line b. The thrust cover 4 is fitted and fixed to the lower end of the inner periphery of the base 2a so as to close the inside.

A shaft holder is constituted by the shaft holder 2 and the thrust cover 4.
The rotary shaft body 5 in the vertical posture in the sleeve portion 2c is rotatably held in a state in which the lubricating fluid 6 such as lubricating oil is held in the gap by capillary action, and constitutes a radial hydrodynamic bearing portion. are doing. Further, in the base 2a and the annular plate 2b of the shaft holding cylinder 2 and the thrust cover 4, the rotating shaft 5
Thrust plate (thrust plate) 7 externally fitted and fixed to the outer periphery of the lower end of the lubricating fluid bearing 7 is rotatably held in a state in which the lubricating fluid 6 is held by capillary action in the gap between the thrust plates 7. Unit. With these radial dynamic pressure fluid bearings and thrust dynamic pressure fluid bearings, dynamic pressure fluid bearings utilizing the dynamic pressure of the lubricating fluid 6 during relative rotation between the rotating shaft 5 and the thrust plate 7 and the shaft holding unit. Is configured.

An annular groove 8 is formed on the outer peripheral surface of the rotary shaft body 5 at a substantially central portion in the height direction, and the annular groove 8 is surrounded by the inner peripheral surface of the sleeve portion 2c. It is configured as a part of a gas intervening portion 10 which is communicated with the outside through a vent hole (breathing hole) 9 formed in the inner peripheral surface thereof.
The gas intervening portion 10 includes the sleeve portion 2c and the rotating shaft 5
Air is interposed all around the gap.

Further, herringbone grooves 11 are formed on the upper and lower surfaces of the thrust plate 7 and on the inner peripheral surfaces of the sleeve portion 2c extending up and down of the gas intervening portion 10, respectively. By the forward rotation of the shaft body 5, a radial load supporting pressure and a thrust load supporting pressure are generated in the lubricating fluid at each position.

Further, a stator 12 in which a motor coil (not shown) is wound around a stator core (not shown) is fixed to the outer periphery of the sleeve portion 2c.
A central hole of a circular concave (cup-shaped) rotor hub 13 is externally fixed to a lower portion of an outer peripheral portion of an upper end of the rotating shaft body 5, and a predetermined interval is provided on an inner peripheral portion of an outer peripheral wall 13 a of the rotor hub 13. Each time the rotor magnet 14 is
And a radial drive unit.

In such a motor, when a radial hydrodynamic bearing and a thrust hydrodynamic bearing are used as the hydrodynamic bearing, the thrust plate 7 is used for the thrust hydrodynamic bearing. In order to stabilize the support in the axial direction (axial direction) (reduce the backlash in the axial direction), the upper and lower surfaces of the thrust plate 7 are used as thrust hydrodynamic bearings.

Here, an outline of a fluid thrust bearing serving as a bearing of the rotating main shaft portion will be described. As described above, the fluid thrust bearing has a disk-shaped flange (thrust plate) provided with a groove (herringbone) for generating dynamic pressure. Thrust plate as actual specification,
This is a bearing that is incorporated in the main shaft of the motor, fills the gap between the support plate (thrust cover) and the thrust plate with fluid, and uses a pressure generated in the fluid when the shaft rotates to float the shaft. In order to increase the recording density as described above, this thrust plate naturally needs to be finished with high accuracy such as flatness, surface roughness, groove depth and the like.

Of course, the outer diameter and runout accuracy of the shaft fixed vertically to the thrust plate are also the same.
It must be finished with high precision. Note that FIG.
As is clear from FIG. 7 and the like, the shaft body and the thrust plate rotate integrally. Therefore, it is not necessary to assemble separately finished ones but to integrally form them from the beginning, which requires an assembling process. May not be desirable in manufacturing.

However, when the outer diameter of the shaft body, the runout accuracy, and the flatness and surface roughness of the thrust plate are taken into consideration, it is more difficult to individually fabricate the shaft than to obtain the final flatness. It is sometimes desirable to integrally assemble components that have been finished with high precision in consideration of manufacturing technology, component size, and the like, and may be able to perform finishing with high precision.

The present invention has been made in view of such a point, and as described in detail below, a thrust plate, which is a molded part formed by a processing means, is a small-diameter disc with a hole, and has a flatness, An object of the present invention is to provide a polishing apparatus for finishing parallelism and the like with high precision and a polishing method used for the polishing apparatus. In the following description of most parts of the small-diameter circular plate with holes, the holes will be omitted for the sake of convenience.

As a method of forming a herringbone groove in the thrust plate, there are a method of performing pressing (press method) and a method of performing etching (etching method). The present inventors have previously described a technique as a pre-stage performed by the press method, as Japanese Patent Application No. 2001-025506 (filed on February 1, 2001, hereinafter referred to as a prior application).
The application has been filed as a “method of manufacturing a molding die”. Hereinafter, the earlier application will be described with reference to FIG.

First, a mold member 20 made of high-speed tool steel (SKH) or the like is placed on its surface 20 for the above-described reason.
a and 20b are mirror-finished with high accuracy (for example, the parallelism and flatness are each 1 μm or less) (FIG. 18).
(A)) A resist or a resist sheet 21 is applied or stuck on the upper surface 20a of the mold member 20 (FIG. 18B).

For example, the thickness of the resist or the resist sheet 21 or the like to be applied is desirably substantially the same as the depth of the pattern. For example, if the pattern groove is 15
If it is about μm, 2
Select a resist thickness such as 5 μm which is the same as the thickness of the plating to be applied. Thereafter, after positioning is performed with reference to the outer periphery of the mold member 20 or the like, the pattern is exposed and developed by, for example, an electron beam, and is patterned on the resist 21 to obtain predetermined resist patterns 22a to 22n (FIG. 18 (c)).

Thereafter, by plating in a plating bath (not shown), a predetermined thickness of the plating layer 23 is formed between the predetermined resist patterns 22a to 22n (parts where the resist is missing) obtained by the above-described patterning.
A composite substrate 24 on which a to 23d (which will be a preliminary mask pattern to be described later) has been obtained is obtained (FIG. 18D). Plating is performed with hard Cr or the like.
Use etc.

After completion of the plating step, the composite substrate 24
Only the resist patterns 22a to 22n in, for example,
Peeling (removing) by a peeling agent, ashing, or the like, a mold 25 having preliminary mask patterns 23a to 23d having a predetermined thickness L is obtained (FIG. 18E).

Next, with reference to the back surface 20b of the mold member 20 constituting a part of the mold 25, machining the plated tip 23a ₁ ~23d ₁ portion having a predetermined thickness L (grinding, etc.) Thereby, it is possible to obtain a desired molding die (nesting) 30 in which the final patterns 26a to 26d having a predetermined height (groove depth) H are accurately finished (FIG. 18F). At this time, the desired final patterns 26a-2
Since the processing standard for obtaining 6d is on the back surface 20b of the mold member 20 that has been finished with high precision as described above, the final finishing can be easily performed.

As described above, according to the above-mentioned application, a molding die can be obtained without performing transfer, so that a molding die of a fine pattern having no missing or chipped pattern can be reliably manufactured. . Further, since the processing reference surface after plating is formed in advance, it is easy to obtain the flatness of the tip of the peak and the parallelism with the reference surface, and a mirror surface can be obtained for both the peak and the valley surface of the pattern.

As described above, the parallelism and the flatness of the back surface 20b of the mold member 20 are each finished with a high precision of 1 μm or less, so that the upper surface 26a of the final patterns 26a to 26d after machining. _{1 to} 26d ₁ are those which can easily obtain a desired flatness (for example, 1 μm or less). Accordingly, by forming the final patterns 26a to 26d in a predetermined groove shape, the molding die 30 is disposed above and below the press machine (movable die, fixed die), and between the upper die and the lower die. Inject molding material to be processed, for example,
By pressing, a thrust plate having grooves (herring bones) for generating dynamic pressure with predetermined accuracy can be obtained.

By the way, generally, the surface of a thrust plate formed by a press method or the like has variations in the height of the upper surface of the groove, edge burrs, and the like, and flatness and surface roughness as required accuracy can be obtained. Absent. Although the earlier application was an effective application for eliminating such a problem, there are some limitations to further improve the accuracy. Therefore,
As shown in FIGS. 19 (a) to 19 (d), a surface finishing step is added after press molding to obtain, for example, the accuracy defined by the standard.

That is, FIG. 19 is a process diagram of a thrust plate formed by a general press method or the like.
(A) is a side view showing a state in which, for example, a thrust plate 42 used for a spindle motor is placed on a lower mold 41 in a blank state in which predetermined planar processing has been performed. Reference numeral 40 denotes an upper mold.

FIG. 3B shows a state before the lower mold 41 on which the thrust plate 42 is mounted is moved upward by an unillustrated upward moving means and pressed by the upper mold 40 to obtain a predetermined groove shape. FIG. 4C is a side view showing the state, and FIG. 4C shows that the lower mold 41 further moves up from the state of FIG. FIG. 6 is a side view of a thrust plate 44 after processing taken out of a lower mold 41 by the method. 44a to 44e are edge burrs formed on the upper surfaces of the respective grooves.

FIG. 4D shows the edge burrs 44 a formed on the upper surfaces of the respective grooves in the state of FIG.
-44f, for example, by polishing and surface finishing with an upper polishing member 46 and a lower polishing member 47, for example,
Thrust plate 45 having a predetermined flatness A and surface roughness B
It is a side view which shows the state of.

As a general polishing method for obtaining flatness by surface finishing or the like, wet polishing using free abrasive grains and dry polishing using fixed abrasive grains can be mentioned. Wet polishing is a lapping machine that rotates free abrasive grains (surface plate)
Although it is a thing that is polished by spraying, it is difficult to control the concentration of the free abrasive grains and the spray interval in controlling the amount of shaving, and the lapping machine, so the free abrasive grains may be biased and stable It is difficult to obtain the amount of polishing. Also, cleaning after processing requires the preparation of a dedicated cleaning device.
Not practical. That is, it can be said that the present invention is not suitable for finishing on the order of submicrons intended by the present invention. Hereinafter, one method of this wet polishing will be described.

First, a workpiece is placed and fixed on a lapping machine. Next, loose abrasive grains are sprayed on the lapping machine, and thereafter, the lapping machine is rotated to polish one surface of the workpiece. Next, the polished one side is placed and fixed on a lapping machine so that the other unpolished surface comes out to the surface. Next, the free abrasive grains are sprayed on the lapping machine, and thereafter, the lapping machine is rotated, and the other surface is polished, thereby finishing the polishing of the upper and lower surfaces of the workpiece. Things.

However, according to the above-mentioned wet polishing, the condition of the polished surface is constantly changed due to clogging and abrasion, and it is difficult to stabilize the shaving amount. In addition, the cut facets are entirely mixed in the working fluid such as free abrasive grains, and these are often oily and require a long time for cleaning. Further, supply (spraying), discharging (unloading), and the like also require time, and it is difficult to reduce the target tact time.

As a polishing method which can solve these problems of the wet polishing, there is a dry polishing method using a wrapping tape.

[0034]

According to the dry polishing method using the wrapping tape, the workpiece can be sequentially polished while feeding a new surface of the wrapping tape.
The amount of polishing can be stabilized. However, in order to obtain a desired flatness or the like, sending the wrapping tape while rotating the small-diameter disk, which is a workpiece, is due to unstable tension of the wrapping tape, eccentricity of the small-diameter disk, and small-diameter disk. Eccentric load tends to occur, and it is difficult to control the degree of parallelism / flatness on the submicron order and the amount of polishing intended by the present invention.

According to the present invention, as a result of intensive studies in view of the above point, even if the wrapping tape is fed while rotating a small-diameter disc with a hole as a workpiece in order to obtain a desired flatness or the like, A new method that stabilizes the tension on the wrapping tape, thereby eliminating the eccentricity of a small-diameter disk with holes and the eccentric load on the small-diameter disk, and achieving submicron-order parallelism and flatness. A dry polishing apparatus and a polishing method have been devised, and an object thereof is to provide such a polishing apparatus and a polishing method.

The outline of the polishing apparatus according to the present invention will be described. The wrapping tape is firmly fixed to a tape holder having a flat surface, and a small-diameter disc with a hole to be processed is brought into contact with the lapping tape to rotate. The wrapping tape is moved by a horizontal moving mechanism in a direction intersecting the running direction of the wrapping tape. Then, every time one small-diameter disk with a hole is finished, a wrapping tape is fed so that a new tape surface is always brought into contact with the workpiece.
As described above, since the polishing amount is stabilized by always using a new tape surface, the submicron order can be achieved by controlling the speed of rotating the small-diameter disk with a hole, the distance in which the disk moves straight, and the force of contact. And stable polishing can be performed.

[0037]

According to the present invention, in order to achieve the above-mentioned object, according to the first aspect of the present invention, a wrapping tape 70 is supplied from a supply side while applying tension, and the supplied wrapping tape 70 is wound. A pair of wrapping tape supply and winding means 64 and 65 to be taken, and a wrapping tape holding table 77 arranged between the pair of wrapping tape supply and winding means 64 and 65 to finish the wrapping tape running surface 77a with high precision. A wrapping tape running and holding mechanism A for applying tension to the wrapping tape 70 mounted on the wrapping tape holding table 77; and a wrapping tape running and holding mechanism A, which intersects the running direction of the wrapping tape 70. Moving mechanism B that moves in the direction in which the wrapping tape travels and holds In a state where the workpiece 44 to the lapping tape 70 in contact with the slide mechanism has a rotation means 78, 80 for rotating the workpiece 44 81,8
2, 83, 84 and 85.

According to a second aspect of the present invention, there is provided the polishing apparatus according to the first aspect, wherein a center convex and tapered elastic body 92 is provided at a tip of the rotation means 78 and 80.

According to a third aspect of the present invention, the wrapping tape 70 is provided with a pair of wrapping tape supplying and winding means 6.
The workpiece 44 is mounted on a wrapping tape holding table 77 provided between the workpieces 4 and 65 with a predetermined tension applied thereto.
The workpiece 4 is moved by slide mechanisms 81, 82, 83, 84, 85 having means 78, 80 for holding and rotating the workpiece 4.
4 is brought into contact with the wrapping tape 70, and the wrapping tape holding table 77 is moved in a direction intersecting the running direction of the wrapping tape 70 with the workpiece 44 abutting on the wrapping tape 70. Thereby, the workpiece 44 is polished.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. It should be noted that since the following examples are preferred specific examples of the present invention, various technically preferable limitations are added. However, the scope of the present invention is particularly limited in the following description. Are not limited to these embodiments unless otherwise described.

FIG. 1 is an overall view showing a polishing apparatus according to this embodiment, FIG. 2 is a side view of the polishing apparatus, and FIG. 3 is a perspective view of a wrapping tape holding table constituting the polishing apparatus. FIG. 4 is a perspective view showing a state in which a wrapping tape is mounted on a wrapping tape holding table constituting the polishing apparatus. FIG. 5 is a perspective view showing a wrapping tape holding table and a wrapping tape constituting the polishing apparatus. FIG. 6 is a perspective view showing the arrangement of the components on the supply side of the polishing apparatus, and FIG. 7 is a perspective view showing the arrangement of the components on the supply side. It is a perspective view showing the state performed.

As shown in FIGS. 1 and 2, a polishing apparatus 50 according to this embodiment comprises a support plate 52,
53 is fixed, and a top plate 54 is fixed on the columns 52 and 53. On the base plate 51, a traveling and holding mechanism (A) for a wrapping tape, which will be described later, is mounted, and the traveling and holding mechanism (A) for the wrapping tape is moved in the XY directions (in a horizontal plane). The mechanism (B) is mounted. On the other hand, the above-described top plate 54
Is fixed to a slide mechanism (C), which is configured to be movable up and down as will be described later, and has a rotation means for rotating while the workpiece is in contact with the wrapping tape in the running and holding mechanism of the wrapping tape. Is what it is.

Hereinafter, an outline of a specific configuration of this embodiment will be described with reference to FIGS. The polishing apparatus 50 according to the present embodiment requires the lapping tape traveling and holding mechanism (A) and the lapping tape traveling and holding, because the finishing accuracy of the workpiece needs to be high as described above. A moving mechanism (B) for moving the entire mechanism in the XY directions (within a horizontal plane), which is configured to be vertically movable,
A slide mechanism (C) having a rotation means for rotating the workpiece in contact with the wrapping tape in the running and holding mechanism of the wrapping tape is roughly constituted. Hereinafter, each mechanism will be sequentially described with reference to FIGS.

First, the wrapping tape running and holding mechanism (A) will be described mainly with reference to FIGS. In each of the drawings, 64 is a supply roller for attaching a wrapping tape 70 described later, and supplying the wrapping tape 70 at the time of use. A supply roller 65 is sent from the supply roller 64, and a predetermined polishing is completed, that is, used. And a winding roller for winding the wrapping tape 70. 64
a is a supply-side reel disk, when not in use, the other disk 64b is removed as shown in FIG. 6, and when the workpiece is polished, the wrapping tape 70 is attached to the supply-side wrapping tape mounting core 66a. 7, the other disk 64b is attached to the supply-side wrapping tape mounting core 66a from the outside, as shown in FIG. 7, so that the wrapping tape 70 does not fall off.

Reference numeral 65b denotes the other take-up reel disk, and 67a denotes a take-up wrapping tape mounting core. These are the supply-side reel disk 64b and the supply-side wrapping tape mounting core 66a. It has a similar function.

Reference numeral 68 denotes a supply-side bracket fixed on a plate 63 described later. The supply roller 64 and the like are attached to the supply-side bracket 68. Reference numeral 69 denotes a take-up bracket fixed on the plate 63, similarly to the supply-side bracket 68 described above. The take-up roller 69 is mounted on the take-up bracket 69.

Reference numeral 71 denotes a supply-side guide roller mounting block fixed on the plate 63. The supply-side guide roller mounting block 71 has two supply-side guide rollers 73a and 73b in the plate 63 direction. Installed in tandem. The one supply-side guide roller 73b is located below the upper surface of a lapping tape running surface lapping tape holding table 77 (described later).
3).

Reference numeral 72 denotes a take-up side guide roller mounting block fixed on the plate 63. Like the supply side guide roller mounting block 71, there are two take-up side guide rollers 74a. , 74b are mounted in a cascade in the plate 63 direction. Note that, similarly to the supply-side guide roller 73b, the one take-up side guide roller 74b is attached so as to be located below the upper surface of the wrapping tape holding table 77 (to be described below) (toward the plate 63).

Reference numeral 75 denotes a supply-side pressing roller, and 76 denotes a take-up-side pressing roller, which applies a pressing force in a direction indicated by an arrow to a wrapping tape holding table 77 described later by a spring means (not shown). . Numeral 77 denotes a wrapping tape holding table which constitutes a main part of the wrapping tape running and holding mechanism (A).
The specific configuration will be described with reference to FIGS.

In each of the figures, the wrapping tape holding table 77 formed in a substantially trapezoidal shape is provided on the entrance side and the exit side in the running direction of the wrapping tape, respectively, so that the wrapping tape 70 does not shift in the width direction.
7c is engraved in a substantially tapered shape obliquely from a wrapping tape running surface 77a described later.

The wrapping guide portions 77b, 77c
The angle of the wrapping tape is determined by the positional relationship between the one supply-side guide roller 73b and the winding-side guide roller 74b. However, when the wrapping tape is running, the form is as shown in FIGS. Will be formed. Reference numeral 77a denotes a wrapping tape running surface on which the wrapping tape 70 runs, and the wrapping tape running surface 77a is finished with a flatness of 0.3 μm and high accuracy.

Therefore, the wrapping tape 70 mounted on the take-up roller 65 from the supply roller 64 when stationary (not used) is composed of the supply-side pressing roller 75, the winding-side pressing roller 76, the wrapping guide section described above. 7
7b, 77c, etc., the wrapping tape running surface 77
a.

As described above, one of the supply-side guide roller 73b and the winding-side guide roller 74b is connected to the lapping tape running surface 77a of the wrapping tape holding base 77.
By arranging the wrapping tape 70 at a lower position, the tension is always applied to the wrapping tape 70 in the direction of the plate 63 as apparent from FIGS. Reference numeral 87 denotes a clutch brake, which applies back tension to the supply roller 64 described above.

Although not shown, the above-described take-up roller 65 is also provided with the same back tension applying means as the supply roller 64.

Therefore, the flatness of the wrapping tape running surface 77a, the pressing force of the supply side and winding side pressing rollers 75, 76 toward the wrapping tape holding table 77, one of the supply side guide roller 73b and the winding side guide roller 74
b, the tension is applied to the wrapping tape holding base 77 by the positional relationship, the supply is performed by the clutch brake 87, etc., the back tension is applied to the winding rollers 64, 65, and the wrapping guide portions 77b, 77c regulate the widthwise direction. By such an interaction, the wrapping tape 70 when stationary (not used) is arranged on the wrapping tape holding table 77 in a state where an extremely high flatness is obtained.

Next, the moving mechanism (B) for moving the entire wrapping tape running and holding mechanism (A) in the XY directions (in the horizontal plane) will be described mainly with reference to FIGS.

An XY stage base 56 constituting a base portion of an XY slide stage 55 to be described later is fixed on the base plate 51 described above.
On the -Y stage base 56, a Y-direction rail 57 is fixed. Also, on this Y-direction rail 57, Y
A directional slider 58 is mounted movably on the Y-direction rail 57 in the Y-direction. Reference numeral 59 denotes a Y-direction plate which is mounted on the Y-direction slider 58 and moves in the Y direction.

On the other hand, on this Y-direction plate 59, X
The X-direction rail 60 is fixed.
The X-direction slider 61 is mounted on the X-direction rail 60
It is mounted movably on the top in the X direction. An X-direction plate 62 is mounted on the X-direction slider 61 and moves in the X-direction.
The plate 63 on which the traveling and holding mechanism (A) for the wrapping tape is placed is fixed.

The XY slide stage 5 described above
Reference numeral 5 denotes the XY stage base 56, Y-direction rail 57, Y-direction slider 58, Y-direction plate 59, X
It comprises a direction rail 60, an X direction slider 61, an X direction plate 62 and the like.

Next, a slide mechanism (C) which is configured to be movable up and down and has a rotation means for rotating while the workpiece is in contact with the wrapping tape in the running and holding mechanism of the wrapping tape is mainly described. This will be described with reference to FIGS.

A rail 85 is fixed to the top plate 54 described above. Numeral 78 denotes a spindle formed in a hollow cylindrical shape, as will be described in detail later, in which a suction means (not shown) is connected. Reference numeral 80 denotes a spindle rotation motor, and 79 denotes a coupling for connecting the spindle 78 and the spindle rotation motor 80 described above. 81 is an air cylinder for pressurizing, and 82 is an air cylinder for pressurizing 8
The first shaft is in contact with one end of a mounting bracket 83 described later.

Reference numeral 83 denotes a mounting bracket for fixing the spindle 78 and the spindle rotating motor 80, and slide portions 84a and 84b are fixed below the mounting bracket 83. The slide portions 84a and 84b are movably mounted on the rail 85 described above. Reference numeral 86 denotes a fixing block for fixing the pressurizing air cylinder 81 provided on the top plate 54.

The slide mechanism (C) is configured as described above, so that when the air of the pressurizing air cylinder 81 is changed, the shaft 82 moves up and down. The mounting bracket 83, one end of which is in contact, moves up and down. Therefore, the spindle 78 fixed to the mounting bracket 83
Etc. also move up and down.

Next, referring to FIG. 8 and subsequent figures, the spindle 7 which is the central part of the polishing apparatus 50 according to the present embodiment will be described.
8, the relationship between the wrapping tape holding table 77, the workpiece 44 and the like will be described. FIG. 8 is a side view showing the relationship between the spindle 78, the wrapping tape holding table 77, the workpiece 44, and the like, which are the central part of the polishing apparatus 50, and FIG.
Is a side view showing the relationship between the spindle 78, the wrapping tape holding table 77, the workpiece 44, and the like in the polishing process. FIG. 10 is a side view showing the relationship between the tip end portion of the spindle 78 and the workpiece 44. 11 is a detailed view in FIG. 8, FIG. 12 is a detailed view of the elastic body 92 in FIG.
Is an explanatory view showing one state at the time of processing the workpiece 44 in the polishing step, and is an explanatory view showing a bad example. FIG. 14 is a view showing one state at the time of processing the workpiece 44 in the polishing step.
FIG. 15 is a side view showing the relationship between the workpiece 44 and the tip of the spindle 78, and FIG.
FIG. 7 is a side view showing a favorable state of the workpiece 44 and the tip of the spindle 78 in the polishing step. The same components as those described above are denoted by the same reference numerals, and a detailed description thereof will be omitted.

First, referring to FIGS. 8 to 12, a stage before shifting from a non-operating (stationary) state to an operating state (before polishing).
The state of each component in will be described. In each of the drawings, a small-diameter circular plate (thrust plate) having a hole as a workpiece after the above-described primary processing is provided on a lapping tape running surface 77a which is finished to a high flatness on the wrapping tape holding table 77 described above. ) 44 are placed. On the other hand, the tip part of the spindle 78 has a tip part 90 of a spindle integrally formed with a protruding part 91 as described later.
Is installed. Reference numeral 92 denotes an elastic body (rubber) inserted into the protruding portion 91. The elastic body 92 has a through hole 93 formed in the center thereof, and a plurality of holes 93 are formed around the through hole 93 as described later. Are formed.

Incidentally, the projection 91 of the tip part 90 of the spindle, the through-hole 93 of the elastic body 92, and the related configuration such as the thickness thereof will be clear in the following description, and therefore will not be described here.

In the state before the polishing as clearly shown in FIGS. 8 to 12, the tip part 90 of the spindle attached to the tip of the spindle 78 has, for example, a projecting part 91 formed integrally therewith. An elastic body 92 having a through-hole 93 formed at the center thereof, which is slightly larger than the outer diameter of the projection 91, is mounted from below. At this time, the length of the protruding portion 91 is, of course, larger than the thickness of the elastic body 92 so that it can be inserted into the hole provided in the workpiece 44 described above.

FIGS. 8 and 11 show this state.
When the pressurizing air cylinder 81 is operated, the shaft 82 is operated.
Moves downward in the direction of the arrow, for example.

Then, a polishing start instruction is issued, and the pressurizing air cylinder 81 and the like are operated.
In this state, the spindle 78 operates in the direction of the arrow, and the projection 91 is inserted into the hole of the workpiece 44. FIG. 9 shows a state in which the projection 91 is inserted into the hole. As described above, the wrapping tape 70 at rest is
Since it is arranged on the wrapping tape holding table 77 in a state where an extremely high flatness is obtained, the clearance state between the protruding portion 91 and the hole is maintained even when shifting from the state shown in FIG. 8 to the state shown in FIG. If desired, polishing will be performed with extremely high precision.

At the time of polishing, the spindle 78 is pressed by a predetermined force in the direction of the arrow in FIG. 9 and the spindle 78 is rotated by the spindle rotating motor 80 in the Y direction (the width direction of the wrapping tape 70). ). When the polishing in the Y direction is completed, the pressurizing air cylinder 81 is operated again in the opposite direction to that described above, so that the spindle 7 is rotated.
8 is moved upward from the wrapping tape holder 77. Thereafter, by operating the take-up roller 65, the wrapping tape 70 that has been polished is taken up by a predetermined amount by the take-up roller 65, and the wrapping tape 70 having a new wrapping tape surface is placed on the wrapping tape holding base 77. Will be brought over.

Next, the state of each component during operation (polishing) will be described with reference to FIGS. As described above, the small-diameter circular plate (thrust plate) 44 with a hole to be processed needs to be finished with high accuracy in flatness, surface roughness and the like. Therefore, at the time of polishing, the spindle tip component 90 attached to the spindle 78, the projection 91 integrally formed with the spindle tip component 90, the elastic rubber 92 attached to the projection 91, and the projection 91 are formed. The components to be inserted, such as the small-diameter circular plate 44 with a hole, to be inserted, need to be assembled with high precision as a matter of course.

As described above, due to the demand for miniaturization, the small-diameter circular plate 44 with a hole, which is a workpiece, has a considerably small shape and a large flatness. Since it must be finished with high precision, polishing is very difficult. Therefore, in the present embodiment, the small-diameter circular plate 44 with the hole is sucked to the tip of the spindle 78 to perform the above operation.

That is, as described above, the spindle 78
Is formed in a hollow cylindrical shape, and suction means (not shown) is connected to the hollow cylinder. On the other hand, an elastic rubber 92 mounted on the protrusion 91 of the spindle tip component 90 is provided at a central portion. Since a plurality of small holes 94 are formed around the through hole 93, the small-diameter disk 44 with the holes is formed by the operation of the above-mentioned suction means (not shown) during polishing. Spindle tip 9 through
It is configured to be adsorbed to zero. Accordingly, if the spindle tip component 90 is finished with high precision, the small-diameter circular plate 44 with holes is naturally assembled with high precision.

As described above, the small-diameter disc 44 with a hole is
Both surfaces must be finished with high precision, and therefore, during polishing, a load must be uniformly applied to the entire disk surface of the small-diameter disk 44 with holes, and
It is necessary to control the speed of rotation and movement with high precision so that the balance of each component is not lost during lapping.

As described above, the small-diameter circular plate 4
4 is inserted protruding portion 91 of the spindle tip part 90 into the hole 44 _1, since it is intended to be polished in a state pressurized to a predetermined direction, and the holes 44 ₁ and the projection 91 is clearance It must be the one specified. This will be described with reference to FIGS.

FIG. 13 shows the workpiece 44 in the polishing step.
Explanatory diagram showing one state at the time of processing, showing a bad example,
FIG. 14 is a diagram illustrating a state in which the workpiece 44 is processed in the polishing step, and is a diagram illustrating a good example.

In both figures, the hole of the small-diameter circular plate 44 with a hole and the projecting portion 91 of the spindle tip part 90 are formed with a predetermined clearance (gap) in the assembling process. Therefore, as shown in FIG.
But, if mounted at all times in the central portion of the bore 44 ₁ of the small diameter disk 44 with holes, because the clearance is the same, small diameter disk 44 with the hole in the absence of eccentricity polishing It will be processed.

[0078] However, as shown in FIG. 13, the protrusion 91 that is, when it is attached to from the biased position the central portion of the bore 44 ₁ of the small diameter disk 44 with holes, is mounted in a state of so-called eccentric If the spindle 78 rotates, the small-diameter disc 4
4 becomes unstable, that is, a load is not uniformly applied to the entire surface of the small-diameter circular plate 44 with holes, so that the amount of polishing varies depending on the surface, and the difference in the amount of polishing reduces the desired surface accuracy, for example. You can't get it.

Therefore, in this embodiment, the small-diameter circular plate 4 having a hole is provided.
This problem has been solved by making the shape of the portion that comes into contact with 4 into a new shape, and that point will be described below with reference to FIGS.

FIG. 15 shows the workpiece 44 and the spindle 78.
FIG. 16 is a side view showing a favorable state of the workpiece 44 and the tip of the spindle 78 in the polishing step.

As shown in FIG. 15, in this embodiment,
As a device for removing eccentricity, a small-diameter disc 4
The contact portion 92a of the elastic body 92 contacting with the protrusion 4
There is a tapered middle convex shape. in this way,
The abutting portion 92a of the elastic body 92 is formed in a tapered shape of a middle convex.
As a result, the spindle 78 moves downward from the state shown in FIG.
When the state is shifted to the state shown in FIG.
The boundary between the two from the inside of the elastic body 92 gradually along the taper
Stress in the direction of the tip portion 90a of the spindle,
That is, the force from the outer side to the inner side is applied to the elastic body 92.
And when the force reaches the boundary 90a,
The force acts on the elastic body 92 from the inside to the outside.
Force will be applied, that is, eccentricity will be eliminated
Power (F ₁, F_Two) Works. Therefore, this elastic body 92
Small-diameter disc 44 with a hole, which is the workpiece contacting the
Is a transition to a state without eccentricity as shown in FIG.
You.

According to this embodiment, the contact portion 92a of the elastic member 92 is formed in a tapered shape with a convex center.
Of course, 0a may be a middle convex tapered shape.

Next, a small-diameter circular plate 4 having a hole as a workpiece.
The polishing process No. 4 will be described. In the following description, a wrapping tape 70 is wound from the supply roller 64 to the winding roller 65, and the wrapping tape 70
Is set on the wrapping tape holding table 77 with high accuracy.

As described above, when the wrapping tape 70 is set on the wrapping tape holder 77 with high precision, the small-diameter circular plate 44 with holes, which is a workpiece, is placed at a predetermined position on the wrapping tape holder 77. One surface to be polished is arranged, and then a start button (not shown) is pressed. When a start button (not shown) is pressed, a small-diameter disc 4 with holes is processed by a positioning chuck (not shown) arranged in the spindle 78.
4 is held, and then the spindle 78 is turned to the air for pressurization.
The cylinder 81 moves to a predetermined lowering position.

When the movement to the predetermined position is completed, the spindle 78 is lowered again by the pressurizing air-cylinder 81, and the projecting portion 91 of the tip end portion 90 of the spindle attached to the tip end has a small diameter with a hole. Hole 44 in disc 44
Enter within ₁ .

Then, the above-described positioning chuck (not shown) releases the holding on the small-diameter disk 44 with holes described above, and instead, suction means (sensor) (not shown) sucks on the small-diameter disk 44 with holes. Start. According to this embodiment, since the small-diameter disc 44 with holes is first held by the positioning chuck, the set position of the small-diameter disc 44 with holes is always constant, so that stable polishing is performed. You can enter the process.

At the time of this suction, the contact portion 92a of the elastic body 92 which comes into contact with the small-diameter disc 44 having a hole as described above.
Is formed in a tapered shape, the eccentricity is absorbed by the taper, and the eccentricity is absorbed thereafter. Therefore, by this mechanism, a small-diameter disk with a hole can be stably rotated without slipping against rotation of a spindle 78 described later.

When a suction sensor (not shown) is turned on,
Pressurization to the spindle 78 is started by the pressurizing air cylinder 81. When the pressurization is completed, the spindle 78 rotates. When the spindle 78 reaches the set number of rotations, the Y-direction plate 59 of the XY slide stage 55
Operate in the Y direction. That is, the plate 63 on which the traveling and holding mechanism (A) of the wrapping tape is mounted moves in the Y direction, and the polishing operation is started.

When the Y-direction plate 59 of the XY slide stage 55 operates in the Y-direction, the spindle 78 starts to rotate and is linearly fed a distance sufficient to polish the target polishing amount. is there. When the polishing for the set distance is completed, the spindle 78 stops its rotation.

When the rotation of the spindle 78 is stopped, the pressurization of the spindle 78 by the pressurizing air cylinder 81 is stopped. When the pressurization of the spindle 78 is stopped,
The suction sensor is also turned off, and the polished workpiece can be removed.

Thereafter, the pressurizing air cylinder 81 is restarted and the spindle 78 moves upward. Then, the winding roller 65 is operated in accordance with the upward movement, and the wrapping tape 70 is wound by the width used in the polishing. Therefore, the wrapping tape 70 placed on the wrapping tape holding base 77 always comes to have a new surface of the wrapping tape 70 when the next work (the small-diameter disc 44 with a hole) is polished. is there.

When a predetermined amount of the wrapping tape 70 is wound by the winding roller 65, the Y-direction plate 59 of the XY slide stage 55 operates in a direction opposite to the Y-direction to return to the original position. Return. In this manner, one surface of the small-diameter circular plate 44 with holes is obtained as a highly accurate finished state.

Here, the moving mechanism in the X direction will be described. The moving mechanism in the X direction mounts the running and holding mechanism (A) of the wrapping tape at the stage where the movement in the Y direction is completed when a sufficient polishing amount cannot be obtained only by the movement in the Y direction. By moving the plate 63 slightly in the X direction and then in the Y direction (in this case, in the opposite Y direction), a predetermined polishing amount can be obtained (the polishing amount can be increased). It is. This is because the winding of the wrapping tape by the take-up reel causes the wrapping tape to bend, which is not preferable. Therefore, an attempt is made to move the wrapping tape by moving the entire running and holding mechanism (A).

For polishing the other surface of the small-diameter circular plate 44 with holes, the above-mentioned one surface may be inverted and disposed on the wrapping tape holding table 77. Thereafter, polishing is performed by the same procedure as described above, so that a small-diameter disc 44 having holes is formed.
Is obtained as a highly accurate finished state.

According to the polishing apparatus of the present embodiment, the flatness, parallelism, and surface roughness on the order of submicron can be obtained by the above-described configuration.

As a specific example, with a wrapping tape having a particle size of 3 μm, the load is controlled to 5 ± 0.01 kgf, and the control target of the polishing amount: 3 ± 0.5 μm;
19 μm σ0.114 μm Flatness target: 0.23 μm on average for 0.5 or less
σ0.097μm Parallelism target: 0.69μm on average for less than 1μm
σ0.217 μm Surface roughness target: 0.1 on average for Rt 0.3 μm or less
μm σ0.02 μm was obtained. Note that in the description here, σ
Is the standard deviation of the variation.

[0097]

According to the first aspect of the present invention, there is provided a pair of wrapping tape supplying / rewinding means for supplying a wrapping tape from a supply side while applying tension and winding the supplied wrapping tape, and the pair of wrapping tapes. A wrapping tape holder arranged between the tape supply and winding means, the wrapping tape running surface being finished with high precision; and a wrapping tape running and holding for applying tension to the wrapping tape mounted on the wrapping tape holder. A moving mechanism that holds the wrapping tape running and holding mechanism and moves in a direction that intersects the running direction of the wrapping tape; and abuts the workpiece on the wrapping tape in the wrapping tape running and holding mechanism. Slide machine having a rotation means for rotating the workpiece in a set state Having provided the door, in which the flatness, parallelism, surface roughness of the submicron order can be obtained.

According to a second aspect of the present invention, there is provided the polishing apparatus according to the first aspect, wherein a center convex and tapered elastic body is provided at the tip of the rotation means, so that the flatness of the submicron order is improved.
Parallelism and surface roughness can be obtained.

According to a third aspect of the present invention, a wrapping tape is mounted on a wrapping tape holding table provided between a pair of wrapping tape supply and winding means in a state where a predetermined tension is applied to the wrapping tape. The workpiece is brought into contact with the wrapping tape by a slide mechanism having means for holding and rotating, and in a state where the workpiece is in contact with the wrapping tape, the wrapping tape holding table is moved to the wrapping tape. Since the workpiece is polished by moving in a direction intersecting the running direction, flatness, parallelism, and surface roughness on the order of submicrons can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view showing one embodiment of a polishing apparatus according to the present invention.

FIG. 2 is a side view of the polishing apparatus of FIG.

FIG. 3 is a perspective view of a wrapping tape holding table included in the polishing apparatus of FIG. 1;

FIG. 4 is a perspective view showing a state in which a lapping tape is mounted on a wrapping tape holding table constituting the polishing apparatus of FIG. 1;

FIG. 5 is a perspective view showing a relationship between a lapping tape holding table, a wrapping tape, and a pressing roller which constitute the polishing apparatus of FIG. 1;

FIG. 6 is a perspective view showing an arrangement state of components on a supply side constituting the polishing apparatus of FIG. 1;

FIG. 7 is a perspective view showing a state in which a wrapping tape is mounted in the state of FIG. 6;

FIG. 8 is a side view showing the relationship between a spindle, a wrapping tape holding table, and a workpiece which are central parts of the polishing apparatus shown in FIG. 1;

FIG. 9 is a side view showing a relationship between a spindle, a wrapping tape holding table, and a workpiece in a polishing process.

FIG. 10 is a side view showing a relation between a tip portion of a spindle and a workpiece.

FIG. 11 is a detailed view of FIG.

FIG. 12 is a detailed view of an elastic body in FIG. 11;

FIG. 13 is an explanatory view showing one state during processing of the workpiece in the polishing step, showing a bad example.

FIG. 14 is an explanatory diagram showing one state of processing a workpiece in a polishing step, showing a good example.

FIG. 15 is a side view showing a relationship between a workpiece and a tip portion of a spindle.

FIG. 16 is a side view showing a favorable state of a workpiece and a tip end portion of a spindle in a polishing step.

FIG. 17 is a longitudinal sectional view showing a configuration of a generally used hydrodynamic bearing motor.

FIG. 18 is an explanatory view showing a method of manufacturing a molding die according to the earlier application.

FIG. 19 is a process chart of a thrust plate formed by a general press method or the like.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Hydrodynamic bearing motor 2 Shaft holding cylinder 3 Base 4 Thrust cover 5 Rotating shaft 6 Lubricating fluid 7 Thrust plate (thrust plate) 8 Annular groove 9 Vent hole 10 Gas interposed part 11 Herringbone groove 12 Stator 13 Rotor hub 14 Rotor magnet 20 die member 20a surface 20b back surface 21 resist sheet 22a~22n resist pattern 23a~23d plating (preliminary mask pattern) 23a ₁ ~23d ₁ plated tip portion 24 composite substrate 25 mold 26a~26d final pattern 30 molding die 40 Upper mold member 41 Lower mold member 42 Plate member (thrust plate) 43 Thrust plate during primary processing 44 Thrust plate after primary processing 44a to 44e Burr 45 Thrust plate after polishing 46 Upper polishing member 47 Lower part Polishing member 50 Polishing device 51 Base plate 52, 53 Support 54 Top plate 55 XY slide stage 56 XY stage base 57 Y direction rail 58 Y direction slider 59 Y direction plate 60 X direction rail 61 X direction slider 62 X direction plate 63 plate 64 supply roller 64b supply-side reel disk 65 take-up roller 65b take-up reel disk 66a supply-side wrapping tape mounting core 67a winding-side wrapping tape mounting core 68 supply-side bracket 69 winding-side bracket 70 wrapping Tape 71 Supply-side guide roller mounting block 72 Take-up side guide roller mounting block 73 Supply-side guide roller Assy 74 Take-up side guide roller Assy 75 Supply-side pressing roller 76 Take-up side pressing roller 77 Wrapping tape holder 77a Wrapping tape running surface 77b Supply side wrapping tape guide 77c Winding side wrapping tape guide 78 Spindle 79 Coupling 80 Spindle rotation motor 81 Pressurizing air cylinder 82 Shaft 83 Mounting bracket 84a Slide 84b Slide 85 Rail 86 Fixed Block 87 Clutch brake 90 Spindle tip part 91 Projecting part 92 Elastic body 92a Taper part 93 Through hole 94 Small hole

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takatoshi Hidaka 3-12 Moriyacho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture F-term in JVC, Ltd. 3C043 BA03 BA16 CC05 CC07 DD01 DD04 DD05 3C058 AA05 AA05 AA11 AA11 AA14 AA16 AB01 AB04 CB01

Claims (3)

[Claims] 1. A pair of wrapping tape supply and winding means for supplying a wrapping tape from a supply side while applying tension and winding the supplied wrapping tape, and between the pair of wrapping tape supply and winding means. Placed, the wrapping tape running surface with high precision finished wrapping tape running surface, a wrapping tape running and holding mechanism for applying tension to the wrapping tape mounted on the wrapping tape holding stage, A moving mechanism that holds a holding mechanism and moves in a direction that intersects the running direction of the wrapping tape; and the work piece in a state where the work piece contacts the wrapping tape in the wrapping tape running and holding mechanism. And a slide mechanism having rotation means for rotating the rotation. Polishing equipment. 2. A polishing apparatus according to claim 1, wherein a center-convex and tapered elastic body is provided at a tip of said rotation means. 3. A means for wrapping a wrapping tape on a wrapping tape holding table provided between a pair of wrapping tape supply / winding means with a predetermined tension applied thereto, and holding and rotating the workpiece. The workpiece is brought into contact with the wrapping tape by a slide mechanism having a direction in which the wrapping tape holding table intersects the running direction of the wrapping tape while the workpiece is in contact with the wrapping tape. Wherein the workpiece is polished by moving the workpiece.