JP2001146906A - Fluid actuator and fine positioning device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly and finely drive a rod with a low cost. SOLUTION: A plate spring 35 of high rigidity for providing a piston rod 29 with the elastic force in the direction opposite to the projecting direction of the piston rod 29 is mounted. The plate spring 35 is fixed to a cylindrical tube 26 through a plate spring holder 31. The plate spring 35 and a point part of the piston rod 29 are integrally fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid actuator for finely driving a rod provided inside a cylinder tube and a fine positioning device using the same.

[0002]

2. Description of the Related Art For example, a semiconductor manufacturing apparatus employs a fine movement positioning apparatus for finely positioning a semiconductor chip with respect to a printed wiring board. In order to finely move the semiconductor chip, a piezoelectric element has conventionally been generally used. That is, the piezoelectric element has a characteristic of expanding when a predetermined voltage is applied. for that reason,
By controlling the magnitude of the voltage value, the number of piezoelectric elements
μm stretched.

[0003]

However, the conventional fine-movement positioning apparatus uses an expensive piezoelectric element or an expensive piezo driver for amplifying the voltage applied to the piezoelectric element, which increases the cost. There was a problem.
Further, since the piezoelectric element has a hysteresis of 10 to 15% with respect to the amount of expansion and contraction, the positioning accuracy of the semiconductor chip is low. Therefore, in order to reduce the hysteresis,
Some include a correction circuit. When a predetermined voltage value is applied to the piezoelectric element, the correction circuit detects a displacement of the piezoelectric element according to the voltage value. When the displacement amount corresponding to the predetermined piezoelectric value is not obtained, the voltage value applied to the piezoelectric element is corrected and controlled according to the detection result. However, even in this case, since an additional correction circuit is required,
As a result, there is a problem that the cost is increased.

[0004] The present invention has been made in view of the above problems, and a first object of the present invention is to provide a fluid actuator capable of accurately and minutely driving a rod at low cost. Another object of the present invention is to provide a fine-movement positioning apparatus having high semiconductor chip positioning accuracy.

[0005]

According to the first aspect of the present invention, a rod is provided in a cylinder tube so as to be reciprocally movable, and the rod is minutely driven. In the actuator, a high-rigidity elastic body that applies elastic force to the rod in a direction opposite to a direction in which the rod protrudes is fixed to the cylinder tube, and the elastic body and the rod are integrally fixed. Is the gist.

According to a second aspect of the invention, in the fluid actuator according to the first aspect, the gist is that the elastic body is sandwiched by a pair of sandwiching members fixed to the cylinder tube.

According to a third aspect of the present invention, in the fluid actuator according to the first or second aspect, the rod is disposed on the cylinder tube side at a position between the cylinder tube and the elastic body. Components,
The first component is configured to be separated from the second component disposed on the elastic body side, and the first component is capable of abutting on the second component while the tip reaches the stroke end. And

According to a fourth aspect of the present invention, there is provided a fine movement positioning apparatus for finely driving and positioning a semiconductor chip with respect to a printed wiring board. Make a summary.

The "action" of the present invention will be described below. According to the first aspect of the present invention, the elastic body is deformed by projecting the rod. An elastic force accompanying this deformation is applied to the rod. Therefore, the projecting position of the rod is determined by the balance between the thrust of the rod and the elastic force of the elastic body. As a result, it is possible to precisely drive the rod minutely.

According to the second aspect of the present invention, since the elastic member is sandwiched between the pair of holding members fixed to the cylinder tube, the elastic member can be securely fixed to the cylinder tube at low cost. it can.

According to the third aspect of the present invention, at a location between the cylinder tube and the elastic body, the rod is separated by two components. For this reason, the elastic body may be assembled so that the tip of the first component contacts the second component before the piston rod projects and reaches the stroke end. That is, both components need not be in contact when the piston rod is immersed.
Therefore, relatively high assembling accuracy is not required for positioning when assembling the elastic body.

According to the fourth aspect of the present invention, since the fluid actuator of the first to third aspects is used, the semiconductor chip can be reliably positioned at a predetermined position.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, fine movement positioning device 11
A ball screw 13 is rotatably supported via two bearings 14 on a base 12 provided on the base 12. A servomotor 15 is drivingly connected to one end of the ball screw 13. A moving body 17 is connected to the ball screw 13 via a screwing piece 16.
The moving body 17 is supported by a support 18. The moving body 17 reciprocates in the left-right direction in FIG. 1 by rotating the ball screw 13 in the forward and reverse directions with the driving of the servo motor 15.

A rail 19 is provided above the moving body 17, and a slider 20 is provided on the rail 19 along its longitudinal direction. A semiconductor chip 21 is provided on the upper surface of the slider 20. Moving object 1
A mounting portion 22 is provided upright at one end of 7, and an air cylinder 25 as a fluid actuator is fixed to a side surface thereof.

As shown in FIGS. 2 and 3, the air cylinder 2
A piston (not shown) is slidably accommodated in the fifth cylinder tube 26. The inside of the cylinder tube 26 is partitioned into two pressure action chambers by the presence of the piston. A first supply / discharge port 27 and a second supply / discharge port 28 are formed on the upper surface of the cylinder tube 26. The first supply / discharge port 27 communicates with the pressure action chamber on the rod side, and the second supply / discharge port 28 communicates with the pressure action chamber on the head side.

When air as a fluid is supplied from the first supply / discharge port 27, the piston rod 2
9 is immersed in the cylinder tube 26. Further, when air is supplied from the second supply / discharge port 28, the piston rod 29 projects from the cylinder tube 26. In the present embodiment, the distance from the stroke end on the head side to the stroke end on the rod side, that is, the full stroke of the piston rod 29 is 7.5 μm.

A cylindrical leaf spring holder 31 is provided on one end surface of the cylinder tube 26. The leaf spring holder 31 is fixed by four screws 32 penetrating along the axial direction of the cylinder tube 26. The leaf spring holder 31 has a first holding member 33 and a second holding member 34 serving as holding members divided at a central portion in the axial direction.
It is composed of

As shown in FIGS. 2 and 4, a circular leaf spring 35 is interposed between the first and second holding members 33 and 34. Then, the first and second holding members 33, 34
These are connected and fixed by a plurality of tightening screws 36 provided at the corners of the leaf spring holder 31. Thus, the leaf spring 35 is fixed in a state of being sandwiched by the pair of holding members 33 and 34.

The material for forming the leaf spring 35 is a high-rigidity stainless steel. The thickness of the leaf spring 35 is 0.1
It is set to 0.4 mm. The reason for setting the thickness in this range is that when the thickness of the leaf spring 35 is smaller than 0.1 mm,
This is because the rigidity of the leaf spring 35 decreases. Conversely, leaf spring 3
If the thickness of the plate 5 is larger than 0.4 mm, the rigidity of the leaf spring 35 becomes too high, so that it is impossible to obtain a suitable elastic deformation. The thickness of the leaf spring 35 is 0.2 to
It is more preferable to set it to 0.3 mm.

The piston rod 29 has a tip portion penetrating through the center of the leaf spring 35. At a location between the cylinder tube 26 and the leaf spring 35, the piston rod 29 is separated into two components 37 and 38. That is, the piston rod 29 has a first component member 37 on the proximal end side and a second component member 38 on the distal end side.
It is composed of The first component 37 is disposed on the cylinder tube 26 side, and the second component 38 is
It is arranged on the 5th side.

The second component 38 comprises a cylindrical body 39 having a female thread on the inner peripheral surface and a fixing screw 40.
A fixing screw 40 is fastened to the cylindrical body 39 in a state where the cylindrical body 39 is in contact with the side surface of the leaf spring 35. Thus, the second component 38 is integrally fixed to the leaf spring 35. Another good thing is piston rod 2
9 is fixed to the leaf spring 35. Then, as shown in FIGS. 5 and 6, while the piston rod 29 reaches the stroke end on the rod side, the tip of the first component member 37 is pressed against the elastic force of the leaf spring 35 by the second component member. 38 is pressed against the end face.

Next, the operation of the fine movement positioning device 11 configured as described above and the air cylinder 25 used therein will be described. In the present embodiment, the fine positioning device 11 is used in a semiconductor manufacturing apparatus to finely move and position the semiconductor chip 21 with respect to a printed wiring board (both not shown). More specifically, when the ball screw 13 is rotated by the rotation of the servomotor 15, the moving body 17 moves along the axial direction. By this movement, the semiconductor chip 21 is roughly moved to a predetermined position. Next, the cylinder 39 of the air cylinder 25
Projecting, the slider 20 moves. By this movement, the semiconductor chip 21 is finely fed to a predetermined position, and the positioning is completed.

The operation of the air cylinder 25 will be described in detail. As shown in FIG. 5, when there is a piston (not shown) at the stroke end on the head side, the first component 37 and the second component 38 are slightly separated from each other. When air is supplied to the second supply / discharge port 28 in this state, air is introduced into the head-side pressure action chamber, and the pressure in the chamber increases. Then, the piston and the piston rod 29 move in the direction of the rod side (that is, the left side in FIG. 2). Before the piston rod 29 reaches the stroke end on the rod side, the tip of the first component 37 abuts on the end face of the second component 38.

Then, as shown in FIG. 6, when the first component 37 moves further toward the rod, the second component 38 also moves toward the rod against the elastic force of the leaf spring 35. In short, the elastic force of the leaf spring 35 is applied to the piston rod 29 in a direction opposite to the direction in which the piston rod 29 moves to the rod side. Elastic force of leaf spring 35 and piston rod 29
The protruding position of the piston rod 29 is determined by the balance with the thrust.

When air is supplied to the first supply / discharge port 27 with the piston at the stroke end on the rod side, air is introduced into the rod-side pressure action chamber, and the pressure in the chamber increases. Then, the piston rod 29 moves in the direction of the head (ie, the right side in FIG. 2). Before the piston rod 29 reaches the stroke end on the head side, the tip of the first component 37 is separated from the end face of the second component 38.

FIG. 7 is a graph showing the relationship between the position of the tip of the piston rod 29 and the supply pressure of air. The hysteresis curve A shows the case where the piston rod 29 moves to the rod side (during the protruding operation), while the hysteresis curve B shows the case where the piston rod 29 moves to the head side (during the immersion operation). According to this graph, the displacement of the tip position of the piston rod 29 in each of the hysteresis curves A and B is L = ± maximum with respect to the ideal straight line C.
It is shifted by 0.1 μm. Therefore, the piston rod 29
The hysteresis for the full stroke of 7.5 μm is ±
It can be within the range of 1.3% (± 0.1 / 7.5 = ± 1.3). Therefore, the hysteresis curves A and B are
In each case, the linearity is high, and it can be said that the tip position of the piston rod 29 is substantially proportional to the air supply pressure.
That is, it can be said that the hysteresis is extremely small.

Therefore, according to the present embodiment, the following effects can be obtained. (1) In the air cylinder 25 of the present embodiment, a high-rigidity leaf spring 35 that applies an elastic force to the piston rod 29 in a direction opposite to a direction in which the piston rod 29 projects is provided. This leaf spring 35 is fixed to the cylinder tube 26 via the leaf spring holder 31. And leaf spring 3
5 and the tip of the piston rod 29 are integrally fixed. Therefore, the piston rod 29 can be minutely driven with a low-cost and simple configuration without using an expensive piezoelectric element or an expensive piezo driver that amplifies the voltage applied to the piezoelectric element. In order to reduce the hysteresis curve due to the relationship between the air supply pressure and the tip position of the piston rod 29, it is not necessary to provide a mechanism or a circuit for controlling the piston rod 29 for correction. As a result, manufacturing costs can be further reduced.

(2) In the air cylinder 25 of the present embodiment, the leaf spring 35 is sandwiched between a pair of sandwiching members 33 and 34 fixed to the cylinder tube 26. Therefore, the leaf spring 3 has a simple structure.
5 can be securely fixed to the cylinder tube at low cost.

(3) In the air cylinder 25 of the present embodiment, the piston rod 29 is separated at a location between the cylinder tube 26 and the leaf spring 35. Then, the first constituent member 3 disposed on the cylinder tube side
Reference numeral 7 is such that the piston rod 29 abuts on a second component member 38 disposed on the leaf spring 35 side while reaching the stroke end on the rod side. Therefore, when the piston rod 29 is at the stroke end on the head side, the first component 37 and the second component 38 may be separated. Therefore, when assembling the leaf spring 35 to the cylinder tube 26, relatively high assembling accuracy is not required for positioning the leaf spring 35. As a result,
The leaf spring 35 can be easily assembled, and the air cylinder 25 can be easily manufactured.

(4) Fine movement positioning device 11 of this embodiment
In the above, since the air cylinder 25 is used, the semiconductor chip 21 can be reliably positioned at a predetermined position with respect to the printed wiring board.

(Second Embodiment) Next, a second embodiment of the present invention will be described focusing on parts different from the first embodiment.

Now, in the second embodiment, as shown in FIGS. 8 and 9, unlike the first embodiment, the piston rod 2
A configuration is adopted in which the front end portion of 9 is not separated.
A disc spring 45 as an elastic body is housed in the cylinder tube 26. The piston rod 29 penetrates the center of the disc spring 45, and the piston rod 29 is integrally fixed to the disc spring 45 by welding. or,
The outer edge of the disc spring 45 is fixed to the cylinder tube 26 by welding. Note that the outer edge of the disc spring 45 need not be fixed to the cylinder tube 26.

According to the present embodiment, by employing the above-described configuration, when air is introduced into the head-side pressure action chamber, the piston and the piston rod 29 move to the rod side. At this time, the piston rod 29 moves while being provided with an elastic force accompanying the deformation of the disc spring 45. Therefore, also in the present embodiment, the protruding position of the piston rod 29 is determined by the balance between the elastic force of the disc spring 45 and the thrust of the piston rod 29, as in the first embodiment.

Therefore, in the second embodiment, substantially the same effects as in the first embodiment can be exhibited.
Further, in the second embodiment, since a leaf spring holder or the like for mounting the disc spring 45 is not required, the number of components can be reduced, and the manufacturing cost can be further reduced.
Further, since the disc spring 45 is provided inside the cylinder tube 26, it is possible to prevent the entire air cylinder 25 from becoming large.

The embodiment of the present invention may be modified as follows. In the first embodiment, the piston rod 29 is not composed of the two constituent members 37 and 38, but is formed integrally with the two members 37 and 38, and the one piston rod 29 whose tip portion is not separated. May be configured. In this case, it is preferable that the piston rod 29 is penetrated through the leaf spring 35 and the leaf spring 35 and the piston rod 29 are fixed by welding.

In the first embodiment, the plate spring 35 may be replaced with the disc spring 45 shown in the second embodiment. In this case, a flange is protruded along the outer edge of the disc spring 45, and the flange is sandwiched between the sandwiching members 33 and.

In the first embodiment, when the piston rod 29 is at the stroke end on the head side, the positional relationship may be set such that the first component 37 and the second component 38 are in contact with each other. .

In the first embodiment, the leaf spring 35 is sandwiched between the sandwiching members 33 and 34 and the leaf spring 3
5 may be fixed to the sandwiching members 33 and 34 by welding.

In the first and second embodiments, it is also possible to embody an air bearing cylinder, a hydraulic cylinder or the like instead of an air cylinder. Next, in addition to the technical ideas described in the claims, technical ideas grasped by the above-described embodiments are listed below together with their effects.

(1) The fluid actuator according to any one of claims 1 to 3, wherein the elastic body is a leaf spring. With this configuration, the configuration of the fluid actuator can be simplified.

(2) The fluid actuator according to any one of claims 1 to 3, wherein the elastic body is a disc spring. With this configuration, the configuration of the fluid actuator can be simplified.

(3) Claims 1-3, (1),
(2) The fluid actuator according to (2), wherein the elastic body is disposed in a cylinder tube, and the elastic body is fixed to an inner surface of the cylinder tube. According to this configuration, since the elastic body can be housed in the cylinder tube, it is possible to contribute to downsizing of the fluid actuator and to improve the appearance.

(4) Claims 1-3, (1)-
(3) The fluid actuator according to any of (3), wherein the elastic body is made of stainless steel. (5) The fluid actuator according to any one of claims 1 to 3 and (1) to (4), wherein the thickness of the elastic body is set in a range of 0.1 to 0.4 mm. .

(6) Claims 1-3, (1)-
(4) In any one of (4) and (4), the thickness of the elastic body may be set to 0.1.
A fluid actuator characterized by being set in a range of 2 to 0.3 mm.

[0046]

As described above in detail, according to the first aspect of the present invention, the rod can be minutely driven accurately at low cost.

According to the second aspect of the present invention, the elastic member can be securely fixed to the cylinder tube despite its simple configuration. According to the third aspect of the present invention, the elastic body can be easily assembled.

According to the fourth aspect of the present invention, the semiconductor chip can be reliably positioned at a predetermined position.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a fine movement positioning device according to a first embodiment.

FIG. 2 is a sectional view of the air cylinder.

FIG. 3 is a top view of the air cylinder.

FIG. 4 is an exploded perspective view of a main part.

FIG. 5 is a schematic diagram when the piston rod is on the head side.

FIG. 6 is a schematic diagram when the piston rod is on the rod side.

FIG. 7 is a graph showing the relationship between the air supply pressure and the tip position of a piston rod.

FIG. 8 is a sectional view of an air cylinder according to a second embodiment.

FIG. 9 is an exploded perspective view of the main part.

[Explanation of symbols]

11 ... fine positioning device, 21 ... semiconductor chip, 25 ...
Air cylinder (fluid actuator), 26: cylinder tube, 29: piston rod, 33: first holding member, 34: second holding member, 35: leaf spring (elastic body), 3
7 First component, 38 Second component, 45 Disc spring (elastic body).

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Mitsuyasu Okabe 2-250, Oki, Komaki-shi, Aichi Fukushima Prefecture F-term (reference) 3H081 AA03 BB03 CC22 CC25 DD13 EE29 FF04 HH04

Claims (4)

[Claims] 1. A fluid actuator in which a rod is provided in a cylinder tube so as to be able to reciprocate, and the rod is minutely driven. An elastic force is applied to the rod in a direction opposite to a direction in which the rod protrudes. A fluid actuator, wherein a highly rigid elastic body is fixed to the cylinder tube, and the elastic body and the rod are integrally fixed. 2. The fluid actuator according to claim 1, wherein the elastic body is sandwiched by a pair of sandwiching members fixed to the cylinder tube. 3. At a location between the cylinder tube and the elastic body, the rod is configured to be separated from a first constituent member disposed on the cylinder tube side and a second constituent member disposed on the elastic body side. And the first component is
While the tip reaches the stroke end, the second
The fluid actuator according to claim 1, wherein the fluid actuator is capable of contacting a constituent member. 4. A fine movement positioning device for finely driving a semiconductor chip with respect to a printed wiring board to position the semiconductor chip, wherein the fluid actuator according to claim 1 is used.