JP2001353683A - Pneumatic retaining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently suspend, grip and convey a workpiece floated in air without contact. SOLUTION: The pneumatic retaining device comprises a retaining surface 5 formed on the lower surface of the circumferential wall 1 of an arm-shaped base E, and a projecting part 3 provided at the center of a cushion chamber 4 formed inside the base E, with the projecting part having a passage 2 open to the cushion chamber 4 or to a lower portion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air holding apparatus for suspending and transporting a plate-shaped work such as a semiconductor wafer or a glass substrate in a non-contact state by blowing air with a hand of a transfer tool such as a robot. It is about.

[0002]

2. Description of the Related Art Conventionally, when a semiconductor wafer, a glass substrate, or the like is transported, there is a step of suspending and transporting the workpieces one by one after predetermined processing for each work is completed.

[0003] In many cases, a vacuum suction method using a suction pad is employed.

For this reason, pad marks may remain on the work surface.

[0005]

Conventionally, a non-contact type hand in which the surface of a work does not directly contact the hand has been proposed.

For example, there is JP-A-62-158831.

This hand utilizes the ejector effect and the Bernoulli effect. However, since the energy of the high-speed air flow immediately after jetting from the flow passage into the cushion chamber is not sufficiently utilized, the energy loss is correspondingly reduced. Yes, the effect was not sufficiently achieved.

SUMMARY OF THE INVENTION It is an object of the present invention to reliably and efficiently suspend and hold a work without causing pad marks on the work.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0010]

Means for Solving the Problems Of the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, an operating surface facing the plate-like work is provided at the lower end of the peripheral wall of the arm-shaped base, and a projection having a flow path for introducing high-pressure air is provided at the center of the arm-shaped base. An opening surface for ejecting air is formed at the tip of the protruding portion, an internal space with the peripheral wall is formed as a cushion chamber, and a high-speed air flow is ejected from the opening surface when the distance to the work approaching the working surface increases. Upon discharge to the outside, the gap between the workpiece and the opening surface, and the gap between the cushion chamber and the working surface serve as a nozzle, a vacuum chamber, and a diffuser of the ejector, respectively.

Therefore, the cushion chamber generates a negative pressure and sucks the work, and when the distance becomes small, the pressure in the cushion chamber is rapidly increased by the pressure chamber type air cushion effect by the high-speed air flow to separate the work. It is characterized by the following.

According to the present invention, the high-speed air flow immediately after being jetted from the opening surface becomes a high-speed air flow when passing through a narrow gap between the opening surface and the work, and generates a large negative pressure due to the Bernoulli effect. There is no energy loss of the high-speed air flow after jetting from the opening surface, and the work can be efficiently suspended and held.

[0014]

Embodiment 1 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a side sectional view showing an air holding device A according to an embodiment of the present invention, and FIG. 2 is a plan view showing a lower portion thereof.

As shown in FIG. 1, a peripheral wall 1 of an arm-shaped base E is provided.
An operating surface 5 opposing the work G is formed at the lower end of the arm, and a projection 3 having a flow path 2 opening to the opening surface 6 at the tip is provided at the center of the arm-shaped base E, and the space inside the peripheral wall 1 is provided. And the cushion chamber 4 to form the air holding device A.

The working surface 5 and the opening surface 6 are formed flush with each other, and the flow path 2 is connected to a high-pressure air C generating source (not shown).

When the distance h between the work G facing the working surface 5 and the working surface 5 is increased, the high-speed airflow C ejected from the flow path 2 passes through the gap between the work G and the opening surface 6 and the cushion chamber. 4 and passes through the gap between the working surface 5 and the work G and is discharged to the outside.

Meanwhile, when passing through the gap between the opening surface 6 and the work G, a negative pressure is generated due to the Bernoulli effect by the high-speed air flow C, and the high-speed air flow C
When the air flows into the cushion chamber 4 and passes through the gap between the operation surface 5 and the work G, the space between the cushion chamber 4 and the operation surface 5 and the work G performs the functions of the vacuum chamber and the diffuser of the ejector, respectively. The cushion chamber 4 generates a negative pressure due to the ejector effect, and generates a negative pressure due to the Bernoulli effect when passing through the gap between the working surface 5 and the work G.

When the work is sucked by the negative pressure generating action and the distance h is reduced, the pressure in the cushion chamber 4 rises due to the pressure chamber type air cushion effect in the cushion chamber 4, and the opening surface 6 and the work G And the gap between the working surface 5 and the work G causes an increase in pressure due to the cushion effect of the high-speed air flow.

The work G is separated by the pressurizing action of the high-speed air flow C.

In this way, the work G is suspended and held in the air holding device A in a non-contact state at the distance h in which the negative pressure or pressure generated inside and the weight of the work G are balanced. .

FIG. 6 shows a pressure generated on the surface of the work G suspended and held by the air holding device A of the present invention, and FIG. 7 shows a pressure diagram in the case of the conventional air holding device F.

In the present invention, as shown in FIG. 6, a high negative pressure is generated between b and d due to the Bernoulli effect due to the high-speed air flow immediately after jetting from the flow path 2, and an efficient ejector effect between d and f. It can be seen that a negative pressure is generated due to.

On the other hand, in the case of the conventional type, as shown in FIG. 7, only the negative pressure is generated due to the ejector effect between b and f, so that the negative pressure is low.

Therefore, the present invention makes effective use of the high-speed air flow immediately after the gas is ejected from the flow passage 2, and the amount of negative pressure generated is remarkably increased as compared with the conventional type, and the suction efficiency is increased. I understand.

[0027]

Embodiment 2 FIG. 8 shows an air holding device L in which an opening surface 6 at the tip of a projection 3 is formed above an operating surface 5.

By making the gap between the work G and the opening surface 6 wide, the inflow resistance of the high-speed airflow spouting from the flow path 2 into the cushion chamber 4 is reduced, and the pressure chamber type generated in the cushion chamber 4 when the work G is sucked. The speed at which the repulsive force is generated by the air cushion effect is increased, and the effect of preventing contact with the working surface 5 by the inertial force at the start of suction of the work G is enhanced.

[0029]

Third Embodiment FIG. 3 is a side sectional view of an air holding device B according to another embodiment of the present invention, and FIG.

Referring to the drawings, a deflecting plate 7 is provided with a gap provided below an opening surface 6 formed on the lower surface of the projection 3 at the center of the cushion chamber 4, and is attached to the inside of the peripheral wall 1 by a bracket 8. To constitute the air holding device B.

With such a configuration, the high-speed airflow C ejected from the flow path 2 is deflected in the horizontal direction by the deflecting plate 7, and the workpiece is ejected from the ejection portion formed by the opening surface 6 and the deflecting plate 7. Since it gushes into the cushion chamber 4 in the direction parallel to G,
High-speed airflow C without directly colliding directly with workpiece G
No local stress due to collision of

The high-speed airflow C ejected from the gap between the deflecting plate 7 and the opening surface 6 flows along the lower surface of the working surface 5 in the horizontal direction, so that the distance h between the working surface 5 and the work G is large. Even in this case, the work is sucked because a negative pressure is generated in the cushion chamber 4 by the ejector effect.

Therefore, even if the work G is flexible or breathable, it can be suspended and held, and even if the work G is fragile, it is not damaged. Even if the distance h to the work 7 is too large, the cushion chamber 4 is always kept. , A negative pressure is generated, so that the work G is not blown off.

Although the deflecting plate 7 is attached to the peripheral wall 1 by the bracket 8, it may be attached directly to the opening surface 6 by screws or the like.

Further, the ejection portion opening to the entire peripheral cushion chamber 4 formed by the gap between the opening surface 6 and the deflection plate 7 may be formed by a number of small holes.

The position of the ejection portion may be above or slightly below the working surface 5.

[0037]

Embodiment 3 FIG. 9 is a side sectional view of an air holding device M of the present invention, and FIG. 10 is a plan view thereof.

Projection 3 formed at the center of cushion chamber 4
A plurality of small holes 13 are opened in the cushion chamber 4 from the flow path 12 whose front end is closed to form an air holding device M.

The high-speed air flow C is ejected from the flow passage 12 through the small holes 13 into the cushion chamber 4.

While the ejected high-speed airflow C passes through the gap between the cushion chamber 4 and the working surface 5 and the work G, a negative pressure is generated by the ejector effect and the Bernoulli effect to suck the work G.

As shown in FIG. 11, the high-speed airflow C jetted from the small holes 13 is jetted into the cushion chamber 4 at an angle, so that the high-speed airflow C does not collide with the workpiece G vertically.
Have a small flow path resistance and pass through the cushion chamber 4, the working surface 5, and the gap between the work G and the working surface 5.

Therefore, the effect of generating a negative pressure due to the ejector effect is high, the suction force is significantly increased as compared with the prior art, and the impact force due to the collision of the high-speed air flow C on the work G is reduced. Relax and protect work G from damage.

In this embodiment, the angle at which the high-speed air flow C is jetted from the small hole 13 is downward, but depending on the position at which the small hole 13 is jetted in the cushion chamber 4 or the nature of the work, it may be appropriately downward, horizontal, or upward. A good angle is also a good example.

[0044] Further, instead of the plurality of small holes 12, a spout that spouts over the entire circumference may be used.

It is also a good example that the cushion chamber 4 is partitioned by the partition plate 14 and the cushion chamber 4 is divided for each small hole 13 ejection position.

[0046]

Embodiment 4 FIG. 5 is a side sectional view of an air holding device H according to another embodiment of the present invention.

Referring to the drawings, an exhaust suction port 10 for supplementing exhaust air discharged from the air holding devices A, B, 1 and M is provided around the air holding devices A, B, M and L.
The air holding device H is configured by mounting the hood 9 provided with the hood 9.

The high-speed airflow C ejected from the flow path 2 passes through the gap between the working surface 5 and the work G and is discharged to the outside.

The high-speed air flow C discharged to the outside is supplemented by the hood 9 mounted around the air holding devices A and B, and is sucked from the exhaust suction port 10 and discharged to a predetermined place.

Therefore, the discharged air does not leak to the external clean room, and the clean room is not contaminated.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the above-described embodiment and can be variously modified without departing from the gist of the invention. Needless to say, there is.

For example, it is also possible to adjust the position of the tip of the projection by adjusting the unevenness of the work, the flexibility, the air permeability, the density of the holes, and the like, thereby adjusting the amount of negative pressure generated.

Further, by providing the contact member on the operating surface, the work can be held and transported in a state where the work is in contact with the contact member, and the displacement of the work can be prevented.

The shapes of the top and side surfaces of the cushion chamber are as follows:
It is also a good example that the shape is not limited to horizontal and vertical, and the ejector effect is effectively generated by the high-speed air flow.

[0055]

The effects obtained by the representative inventions among the inventions disclosed in the present application will be briefly described.
It is as follows.

(1) By providing an opening surface provided with a flow path in the center of the cushion chamber close to the work, the work can be efficiently suspended and suspended in the air without contact.

(2) By jetting a high-speed airflow into the cushion chamber from the small hole on the side surface of the projection, the work can be efficiently suspended and suspended in the air without contact.

(3) As a result, scratches, dirt, and traces of pads do not adhere to the surface of a plate-like work such as a semiconductor wafer or a liquid crystal glass substrate.

(4) Since a hood for collecting exhaust gas is provided, it can be used in a clean room.

(5) Flexibility, air permeability, or holes can be formed, and a fragile work can be held without being damaged.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an embodiment of the present invention.

FIG. 2 is a bottom plan view of the embodiment of the present invention.

FIG. 3 is a side sectional view of another embodiment of the present invention.

FIG. 4 is a bottom plan view of another embodiment of the present invention.

FIG. 5 is a side sectional view of another embodiment of the present invention.

FIG. 6 is a generated negative pressure diagram of an embodiment of the air holding device A of the present invention.

FIG. 7 is a generated negative pressure diagram of the conventional embodiment.

FIG. 8 is a side sectional view of another embodiment of the present invention.

FIG. 9 is a side sectional view of another embodiment of the present invention.

FIG. 10 is a bottom plan view of another embodiment of the present invention.

FIG. 11 is a generated negative pressure diagram according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Peripheral wall 2, 12 Flow path 3 Projection part 4 Cushion room 5 Working surface 6 Opening surface 7 Deflection plate 8 Bracket 9 Hood 10 Exhaust suction port 13 Small hole A, B, H, L, M Air holding device C High-speed air flow E Substrate F Conventional air holding device G Work P High pressure air

Claims (6)

[Claims] 1. An operating surface facing a plate-shaped work and a cushion chamber in an inner space of the arm-shaped base are formed at a lower end of a peripheral wall of the arm-shaped base, and a lower surface or a cushion chamber is formed from an upper surface of the cushion chamber. An air holding device provided with a projection having a flow path that opens. 2. The air holding device according to claim 1, wherein the flow passage opening surface at the tip of the projection is flush with the operating surface. 3. The air holding device according to claim 1, wherein the flow path opening surface at the tip of the projection is above the operating surface. 4. An air holding device according to claim 3, wherein a deflection plate is provided below the flow path opening surface at the tip of the projection, and an opening which opens to the cushion chamber is provided all around. 5. The air holding device according to claim 1, wherein the plurality of small holes communicating with the flow path according to claim 1 are opened to the cushion chamber from the side surfaces of the projection. 6. An air holding device, wherein a hood provided with an exhaust suction port is mounted around the air holding device according to claim.