JPS63300858A - Air bearing type work holder - Google Patents

Abstract

PURPOSE:To easily pressurize a work for a surface plate by jointing a revolution driving shaft and a work guide for press-holding a workpiece on a revolution surface plate through a bellows coupling and supporting the revolution driving shaft and the work guide by an air bearing, in a flow trap device. CONSTITUTION:Before the revolution operation, an air pressure introducing unit 1 and a revolution driving shaft 2 are set into noncontact state by supplying air into an air pressure introducing inlet 10, and the turning moment supplied from the revolution driving shaft 2 is transmitted to a work guide 4 having a plurality of works fixed on the lower part, through a bellows coupling 9, and also a standard guide ring 3 supported by a ball bearing 29 is revolved through a pin 25. When the pressure in the bellows coupling 9 is adjusted through a pressurization control port 12 by a speed controller 38. The work guide 4 air-bearing-supported by the air pocket parts 5-10 presses a work onto a revolving surface plate 28, and polishing is carried out. Therefore, the pressurization for the work onto the surface plate can be varied freely, and the polishing for the work can be carried out efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flow trap device, and particularly to an air bearing type work holder for float polishing for polishing workpieces with high surface accuracy.

[Conventional technology]

In the semiconductor-related field, as demand expands and the production and assembly of high value-added products is streamlined, the demand for high efficiency and precision in polishing, which is the final finishing process for a single component, is increasing. .

In particular, research and development of mirror finishing technology is actively progressing.

Float polishing involves rotating a work table (hereinafter referred to as the "face plate") machined into a highly accurate flat surface under conditions that do not cause any wobbling of the surface, and applying a film of polishing liquid to the surface of the workpiece (hereinafter referred to as the "workpiece"). ) is a polishing method in which the zero plate has a spiral groove, and when the first plate and the workpiece are rotated at high speed, the dynamic pressure fluid lubrication state of the polishing liquid allows them to be polished without contact. In this case, if the workpiece is polished to a mirror surface in advance, a non-contact state can be maintained and the flat surface of the face plate can be transferred to the workpiece as final polishing. The state of polishing is determined by the relationship between the face plate and the workpiece, and is roughly divided into (a) direct contact polishing, (b) quasi-contact polishing, and (c) non-contact polishing, and most polishing is done in one of these two types. belongs to crab.

The air bearing type work holder is a polishing device that does not simply maintain these polishing conditions, but selectively changes them. For example, in the early stages of polishing, a smooth mirror surface is obtained by the mechanical action of rubbing the workpiece against the faceplate, and in the latter half of polishing, the two are kept in a non-contact state and the etching effect of the polishing liquid is used to create a smooth mirror surface. Steps can be taken to ensure an undisturbed surface free of processing defects. At this time, it is necessary to increase machining accuracy and machining efficiency by gradually changing or alternating the contact state between the workpiece and the face plate, and for this purpose, it is necessary to efficiently adjust the pressure of the workpiece that is pressed against the face plate. That is required.

An example of a conventional technique will be described below with reference to the drawings. Fourth
The figure shows a cross-sectional view of a conventional work holder.

A long hole 33 is made in a work shaft 32 to which a work 50 is fixed, a pin 34 is passed through the hole 33, and the pin 34 and a work shaft holder 35 are fixed. Further, the work shaft holder 35 has a structure of 0 or more that holds the work shaft 32 via two linear motion bearings 36, and transmits the rotational force from the rotary drive shaft 2 to the work shaft 32. , face plate 28
It is also possible to move the workpiece 50 up and down relative to it. Work 5
0, in order to increase the surface pressure on the workpiece 50,
It is configured so that a weight 37 can be attached. An example of this one-way system is published in "Polishing Organization J" (P52.
Figure 12).

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not take sufficient consideration to the rotational center deviation and angular deviation between the rotary drive shaft and the face plate, and is therefore unsuitable for polishing a flat surface that requires human-level flatness accuracy. Another problem was that the weight could not be replaced without stopping the operation, and it required a lot of time and manpower to gradually or alternately change the pressure on the workpiece.

An object of the present invention is to solve the above-mentioned problems and efficiently polish a workpiece with high surface accuracy.

[Means for solving problems]

The above object is achieved by connecting a workpiece guide configured to be supported by an air bearing and a rotary drive shaft with a bellows joint, and pressing and fixing the workpiece using air pressure if necessary. That is, the bellows joint or the air cylinder is directly connected to the workpiece pressing part.

[Effect]

The bellows joint transmits the rotational force of the rotary drive shaft to the work guide, but it also easily expands and contracts in the vertical direction. This allows the work guide to rotate while changing its inclination, so that the work surface rotates following the three surfaces of the face plate.

Further, by adjusting the air discharge flow rate, the air pressure of the bellows joint or the air cylinder can be adjusted, thereby adjusting the pressing force of the work guide.

〔Example〕

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

(Embodiment 1) FIG. 1 is a cross-sectional view of an embodiment of an air bearing type work holder according to the present invention.

This mechanism is composed of an air pressure introduction unit 1, a rotary drive shaft 2, a reference guide ring 3, a work guide 4, and the like.

Between the pneumatic lover unit 1 and the rotary drive shaft 2, the reference guide ring 3 and the work guide 4, there is an air pocket 5°6.7.8 (clearance 0.
02 mm), and the one-rotation drive shaft 2 and the reference guide ring 3 are connected with a bellows joint 9.

The air pressure introduction unit 1 is provided with an air pressure introduction port 10, a relay port 11, and a pressurization controller 12.

A tube 16 and a joint 13 are attached to the air inlet IO, and air sent from the air supply source 15 is sealed into the air pressure inlet 10 via the tube 16 and the joint 13.

The enclosed air is discharged to the outside of the aircraft through the air pocket 5 and along the arrow paths a, b, and Q.

The pressure control roller 12 includes a joint 19 and a tube 17.
, a pressure gauge 38, and a speed controller 42 are arranged in this order, and the air branched to the arrow path d is discharged to the outside through these.

Further, a plurality of workpieces 50 to be polished are adhesively fixed to the lower part of the workpiece guide 4, and pins 25 are attached to the workpiece guide 4 and the reference guide ring 3 for the purpose of transmitting rotational force and positioning. An O-ring 26 is attached to the pin 25 to prevent it from becoming difficult during rotation due to metal-to-metal contact. Therefore, the reference guide ring 3 and work guide 4
The work guides 4 rotate at the same time, and since the work guide 4 is an air bearing guide, it can be easily moved up and down along the reference guide ring 3.

Although the structure is not specifically explained here, a rotation drive section 27 is provided on the upper part of the rotation drive shaft 2, and the one-rotation drive section 27 and the rotation drive shaft 2 are completely connected. Therefore, the rotation drive section 27
The rotary drive shaft 2 is rotated by the rotational force transmitted from the rotary drive shaft 2.

Since air is sealed in the air pressure introduction port 10 before rotational operation, the air pressure introduction unit 1 and the rotational drive shaft 2 are in a non-contact state as described above.
No rotational force is transmitted to the

Therefore, in the pneumatic introduction unit 1, the rotational force is suppressed by the tube 16 and the rotational force transmitted from the 0-rotation drive shaft 2 is transmitted to the work guide 4 via the bellows joint 9, and is transmitted to the reference guide ring 3 via the pin 25. Rotational force is also transmitted to the That is, only the air pressure introduction unit 1 is fixed, and all other members rotate on the rotating face plate 28. Here, since the face plate 28 is also rotating, an arm 30 holding two ball bearings 29 at the tip is installed from a part of the fixing member of the rotation drive unit 27, and the arm 30 holds two ball bearings 29.
9 are brought into rolling contact with the outer periphery of the reference guide ring 3 to prevent the air bearing type work holder of the present invention from being swung around by the rotational force of the face plate 28. However, at this time, the reference guide ring 3 is restricted by the two ball bearings 29 attached to the arm 30 and the outer diameter of the reference guide ring 3.
Misalignment between the center of rotation of the face plate 28 and the center of the rotary drive shaft 2 occurs, and a misalignment of the rotation center angle between the rotation axis of the face plate 28 and the rotation drive shaft 2 occurs. The workpiece 24 fits on the upper surface and rotates smoothly.

Next, the pressure adjustment of the workpiece 50 will be explained as follows. When air is filled in the air pressure inlet 1, the clearance for all the air pockets 5, 6, and 7.8 is made equal, so the air flow rate is almost equal and there is no pressure fluctuation, resulting in a pressurization control chamber 12. Although air having the same pressure flows through the pressurization control lobe 12, the flow rate can be adjusted using the speed controller 42 while watching the pressure gauge 38 connected to the pressurization control lobe 12, that is, the bellows joint. It is possible to regulate the pressure inside 9. In addition, there is a pressure P work at the entrance.

Volume V1. If the pressure at the outlet is P29 and the volume is v2, the pressure control lo 1 is determined by Boyle's law p, v, = p, v.
When the bellows joint 9 is released, the pressure inside the bellows joint 9 is close to Okg/am" due to the difference in the cross-sectional area ratio between the pressurization control rod 12 and the air pockets 5, 6, and 7.8 of the air bearing. However, it is necessary to take into account that the pressure inside the bellows joint 9 will be a little higher because there is resistance in the pipe, such as the arrow path d of the air to the pressurization control rod 12, the joint 19, the tube 17, the pressure gauge 38, etc. In other words, if you want to maintain the high pressure inside the air pockets 5.6 and 7.8 and make the pressure inside the bellows joint 9 Okg/am, then in order to reduce the pressure that has increased due to the resistance inside the pipe,
Taking six cases where it is necessary to provide a minute leak hole 31 in the work guide 4 in advance and release a constant flow of air, the pressure at the air pressure inlet 1o is set to 6 kg/cat.
, the pressure loss due to the leak hole 31 is 0.5 kg/am".

Furthermore, assuming that the bottom area inside the bellows joint 9 is 50 am'', the pressure inside the bellows joint 9 is O~5.5kg70
Since the 'riR can be adjusted to 1", the pressing force of the work guide 4 can be reduced from O to 275 kg (5.5 kg / C! II"
50an'').

This embodiment has the following effects.

(a) By using a double air bearing, the joint 14 and tube 16 attached to the air pressure inlet IO do not rotate, which solves the problem of the tube 16 wrapping around the rotational drive shaft 2 (called tube wrapping prevention). From the point of view,
It is also possible to seal the air by using two magnetic fluid seals on the inner air bearing part of the double-pipe air bearing, changing from a non-contact mechanism to a direct contact mechanism, but the present invention is effective in preventing entanglement. Here is an example of one method).

(b) By using a double structure air bearing, the bellows joint 9 can be attached to the inner air bearing part, and the air pressure inside the bellows joint 9 can be maintained without reducing the rigidity of the air bearing in the radial and thrust directions. can be easily adjusted.

(C) Due to the elasticity of the bellows joint 9, the work guide 4
The misalignment of the rotary drive shaft 2 and the angular misalignment of the center of rotation between the rotary drive shaft 2 and the face plate 28 are absorbed, and the workpiece 50 conforms to the upper surface of the face plate 28, allowing for highly accurate polishing.

(Example 2) Another embodiment of the present invention will be described with reference to FIG.

This mechanism is comprised of a pneumatic introduction unit, a rotating shaft 2, a reference guide ring 3, a work shaft 4, a bellows joint 9, and the like. Pneumatic introduction unit 1- and rotational drive shaft 2. Air pockets 5, 6, and 7.8 (clearance 0.02 mm) constituting an air bearing are provided between the reference guide ring 3 and the work shaft 4, and the rotary drive shaft 2 and the reference guide ring 3 are connected to a bellows joint. It is joined at 9.

The workpiece shaft 4, to which the workpiece 50 is adhesively fixed at the lower part thereof, has a collar at its uppermost end and constitutes a piston.

The pneumatic pressure unit 1 is provided with a pneumatic inlet 10 and a pressurization controller 12. A joint 13 and a tube 16 are attached to the air pressure inlet lO, and air sent from the air supply source 15 is sealed therein.

The sealed air is discharged to the outside of the mechanism through the air pockets 5 and 6.7, and the other is through the arrow path a, the joint 14, and the tube 18 to the relay port 11 of the reference guide ring 3. Branched out. Here again, the air sealed in the relay port 11 is divided into the directions C along the arrow path. The air flowing through the path functions as an air bearing guide for the work shaft 4 and is discharged to the outside through the leak hole 31 and arrow d. Arrow route C
The air flowing through the air jacket 24 and the outlet 39
, the joint 21°, the tube 23, the path e, the joint 19, the tube 17, and the dial regulator 38 before being discharged to the outside.

That is, by adjusting the exhaust flow rate of air while monitoring the pressure with the dial regulator 38 during operation, the pressure of the air jacket can be easily adjusted (reducing the flow rate increases the pressure).

A pin 25 is attached to the work shaft 4 as a rotation stopper. An O-ring 26 is provided on the pin 25 to prevent it from becoming distorted due to metal-to-metal contact.

Regarding the rotational drive of this mechanism, the rotational force of the rotational drive unit 27 is transmitted to the rotational drive shaft 2, the bellows joint 9° reference guide ring 3, and the pin 25 to rotate the work shaft 4. Only the air pressure introduction unit 1 is in a fixed state, and all other members are in a fixed state.

It will rotate on the face plate 28 which is rotating at high speed.

This embodiment has the following effects.

(a) The load for pressing the workpiece can be adjusted by adjusting the air exhaust flow rate.

(b) The vertical elasticity of the bellows joint is used to absorb the angular misalignment between the rotation center of the reference guide ring and the face plate, allowing the workpiece to conform to the top surface of the face plate, allowing for highly accurate polishing.

(Example 3) Still another embodiment of the present invention will be described with reference to FIG.

This mechanism is composed of an air pressure introduction unit 1, a rotary drive shaft 2, a work guide 4, a reference guide ring 3, a weight 37, a bellows joint 9, and the like.

Air pressure introduction unit 1, rotation drive shaft 2, work guide 4
Air pockets 5, 6, 7.8 (clearance 0.02m+n
), and the rotary drive shaft 2 and work guide 4 are connected by a bellows joint 9 and an arm 39.

The air pressure introduction unit 1 is provided with an air introduction port 10. In addition, the air inlet 10 includes a joint 13 and a tube 16.
The air sent from the air supply source 15 is sealed through the tube 16 and the joint 13, and the sealed air is divided into air pockets 5, 6.7 and the arrow path a. The air that has passed through the arrow path a flows through the joint 14 and the tube 1.
8 and is enclosed in the work guide relay port 11.

The air flowing into the relay port 11 forms the air pocket 8 and the circumference.

It branches into a groove 40. The air flowing into the air pocket 8 is discharged out of the mechanism via the arrow path c. On the other hand, the air branched into the circumferential groove 40 is introduced into the air pocket 8 of each separate air bearing system via the leak hole 31.

The air that has entered is also discharged via arrow paths d and e.

Note that O-rings 33 are provided above and below the circumferential groove 40 to prevent air from leaking. Further, the work guide 4 and the reference guide ring 3 are completely fixed with screws 41.

A two-rotation drive section 27 is provided on the upper part of the rotation drive shaft 2.

Completely coupled with rotary quick-acting shaft 21. ing. Therefore, the rotational force transmitted from the rotation drive unit 27 is transmitted to the bellows joint 9, the arm 39. The reference guide ring 3 is also rotated via the work guide 4 and the screw 41.

There are air pockets 5, 6.7 of air bearings between the air pressure introduction unit 1 and the rotary drive shaft 2, so there is no contact between them, so rotational force is not transmitted.In other words, only the air pressure introduction unit 1 is rotated by the tube 1G. The force is suppressed and it stands still, while all other members rotate on the face plate 28 which is rotating at high speed.

The weight 37 has a workpiece 50 adhesively fixed to its lower part, and can easily move vertically along the air bearing guide while revolving together with the workpiece guide 4.

Further, a pin 25 is attached to the arm 39 to prevent each weight 37 from rotating. An O-ring 26 is attached to the pin 25 to prevent it from becoming complicated due to metal-to-metal contact.

As described above, this embodiment has the following effects.

(a) The stretchability of the bellows joint 9 is used to absorb the angular deviation between the rotation centers of the rotary drive shaft 2 and the face plate 28, and the workpiece 50 conforms to the upper surface of the face plate 28, allowing for highly accurate polishing.

(b) The weight 37 to which the workpiece 50 is attached can be easily moved in the vertical direction while rotating together with the reference guide ring 3.

〔Effect of the invention〕

By implementing the present invention, the following effects were obtained.

(a) Since the air pressure inside the bellows joint can be easily adjusted, the pressure applied to the workpiece against the surface can be changed freely and in a short time, making it possible to efficiently polish workpieces with a wide range of finished surfaces. .

(b) Since the workpiece is polished while conforming to the face plate, it is possible to prevent the entire mold surface from being polished, which gradually becomes higher toward the center of the workpiece due to rotational center deviation, angular deviation, etc. This eliminates the occurrence of defective products and makes it possible to polish workpieces that require high flatness accuracy.

(Q) It is now possible to polish multiple workpieces with different thicknesses, which eliminates the need for the conventional work of adjusting the thickness of each workpiece during grinding, and can significantly save time and manpower.

(d) Since the work holder has a single structure, Si.

Different materials with different polishing abilities such as AQ and 03 can be polished at the same time.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the air bearing type work holder according to the present invention, FIG. 2 is a cross-sectional view of another embodiment of the present invention, and FIG. 3 is a cross-sectional view of yet another embodiment of the present invention. FIG. 4 is a cross-sectional view of a prior art work holder. 1... Air pressure introduction unit 2... Rotation drive shaft 3... Reference guide ring 4... Work guide 5.6, 7.8... Air pocket 9... Bellows joint 10... Air Inlet port 11...Relay port 12...Pressure controller 13, 14.19.20.21.22...Joint 15.
...Air supply source 16, 17.18.23...Tube 24...Air jacket 25...Pin 26, 33...○Ring 27...Rotary drive unit 28...Face plate 30, 39 ... Arm 37 ... Weight 38 ... Pressure gauge 40 ... Circumferential groove 41 ... Screw 42 ... Speed controller 50 ... Workpiece

Claims (1)

[Claims] 1. In an air bearing type work holder that performs high-speed polishing by interposing a polishing liquid between the workpiece and the face plate, the rotary drive shaft and the workpiece placed on the rotating face plate are pressed. An air bearing type work holder characterized in that it is configured to be connected to a work guide to be held by a bellows joint and supported by a bearing that uses air as a medium. 2. The air bearing type workpiece according to claim 1, wherein the air bearing type workpiece is configured to adjust the pressure applied to the workpiece by enclosing a part of the air in the bellows joint. holder. 3. A patent claim characterized in that the workpiece guide or workpiece shaft that holds the workpiece is provided with an air cylinder that introduces a portion of the air to adjust the pressure applied to the workpiece. The air bearing type work holder described in item 1. 4. The air bearing type according to claim 1, wherein the work guide is configured to pressure-regulate a plurality of workpieces having different machining heights by introducing the air. work holder.