JPH0215461B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a holding device for a flat plate-like member having a smooth surface, and particularly to a holding device used for transporting various substrates for semiconductor manufacturing such as wafers, reticles, and photomasks. Regarding equipment.

``Prior art'' In order to avoid scratches on the surfaces on which high-density circuits are formed on various substrates for semiconductor manufacturing such as wafers, reticles, and photomasks, suction forces generated between the suction surface and the substrate (the member to be held) are used at high speed. It is preferable that the substrate be held on the suction surface in a non-contact manner via a fluid film.

An example of this will be explained based on FIGS. 1A and 1B. Reference numeral 10 denotes a rectangular flat suction plate, the bottom surface of which is flat, and a suction surface 10a for holding the substrate 7 formed therein. An air supply hole 11 penetrating to the upper surface is bored. An air hose 13 is attached to the upper surface side of the air supply hole 11 via a cap nut 12, so that compressed air is supplied to the suction surface 10a side. Further, the suction plate 10 has a key-shaped regulating member 14 at each corner on the side of the suction surface 10a.
a... are fixedly installed to prevent the substrate 7 from sliding down parallel to the suction surface.

According to this comparative technique, while air is being supplied from the air supply hole 11 of the suction plate 10, the regulating member 14 is
An installation surface 16 on which the substrate 7 is placed with the diagonal of the substrate 7 and the suction plate 10 turned by 45 degrees so that the substrate 7 is positioned below the suction surface surrounded by a...
When the suction plate 10 is placed on top, the suction surface 10
a is close to the substrate 7 and the gap distance d is 0.2~
The gap is as small as 0.8 mm, and the air sent from the air supply hole 11 is exhausted outward within the gap at a considerably high air speed, so the negative pressure generated between the gap d causes buoyancy. As a result, the substrate 7 rises from the installation surface and is held close to the suction surface 10a in a non-contact manner via the high-speed air flow membrane.

On the other hand, in such a state, since the substrate 7 is held in a non-contact state on the suction surface 10a,
Since there is a risk that the substrate 7 will slide down parallel to the suction surface due to a slight tilting of the suction plate 10, its position is maintained by regulating members 14a that restrict the sliding.

"Problems to be Solved by the Invention" However, in such a mechanical regulating means, when the suction plate 10 is tilted, the side edge surface of the substrate 7 collides with the regulating member 14a, and particles etc. are generated.
The particles adhere to the circuit forming surface of the substrate 7 and tend to cause product defects.

Also, for example, the board side edge surface 7a has little influence on circuit formation.
Even if the holding members 5 and 6 are held in contact with each other using the In some cases, the holding device 1 used for transporting the substrate 7 was incomplete, as it sometimes flowed down to the circuit forming surface at the center of the surface of the substrate 7.

The technical problem to be solved by the present invention is to provide a holding device that can hold a semiconductor manufacturing substrate or other flat plate-shaped member having a smooth surface in a predetermined position in a completely non-contact state.

"Means for Solving Problems" In order to achieve such technical problems, the present invention divides the bottom surface facing the flat member into two into a central region and a peripheral region, as shown in FIG. 2B. The airflow ejected from the ring-shaped slit opening 23a provided at the boundary causes the peripheral edge side to function as a suction surface 27 capable of suctioning the flat member through a high-speed fluid film, while a recess is formed on the central area side. At the same time, a narrow passage 34 communicating with the recess 35 is opened to the air supply passage 23 on the upstream side of the slit opening 23a, and the suction effect of the air flow flowing through the air supply passage 23 is used to close the recess. A holding device for a flat plate member is proposed, which is characterized in that the flat member 7 is held in position by placing the station 35 under negative pressure and sucked by the suction surface 27.

"Function" According to this technical means, in order to restrict the sliding of the flat member 7 that is suctioned and held via a high-speed fluid film by the fluid action of the recess 35 placed under negative pressure, the smooth surface is It becomes possible to hold the flat plate member 7 in a predetermined position in a completely non-contact state.

Moreover, instead of providing independent air supply passages and suction passages on the central area side and the peripheral area side, the flat plate-shaped member can be sucked on the peripheral side by simply ejecting high-speed airflow from the ring-shaped slit opening 23a. Since it is possible to function as the adsorption surface 27 and to maintain its position by placing the central region side under negative pressure, only one pneumatic air pipe 22 is required, and its polarization performance is greatly improved.

"Embodiments" Hereinafter, preferred embodiments of the present invention will be described in detail by way of example with reference to the drawings. However, the dimensions, materials, shapes, relative positions, etc. of the components described in this example are as follows, unless otherwise specified.
This is not intended to limit the scope of the invention, but is merely an illustrative example.

2A and 2B show a substrate holding device according to an embodiment of the present invention.

The structure of this embodiment will be explained in accordance with the order of air flow. Reference numeral 20 denotes a main body having a threaded portion 21 on its upper end so that it can be attached to a certain type of conveyance device, and a central member 30 on its upper midsection. Main hole 3 drilled on the axis
A compressed air inlet 22 reaching up to 1 is formed.

The central member 30 is provided with an opening 31a at a downstream circumferential portion of the main hole 31, and the opening 31a
An annular orifice 32 is fixedly installed so as to surround 1a.

The annular orifice 32 has a reduced diameter ring-shaped orifice groove 3 formed between the outer periphery of the center member 30
2a, and its outlet side communicates with a ring-shaped slit groove 23 formed between the inner periphery of the main body 20 and the outer periphery of the central member 30. That is, the orifice groove 32a and the slit groove 23 form a so-called fluid amplification section. Therefore, the opening area of the orifice groove 32a is set to be much smaller than the opening area of the slit groove 23.

The upstream side of the ring-shaped slit groove 23 communicates with a sub-hole 25 that is bored from the midsection of the main body 20 and communicates with the outside air via the filter 24, while the downstream side communicates with the outer periphery of the central member 30 formed in a substantially radial shape. An opening 23a is formed along the bottom surface.

The opening 23a allows the airflow to be ejected at a slight angle of inclination, specifically 5.
It is set so that it is below 30 degrees. By forming in this way, the high-speed fluid is injected in a substantially horizontal direction along the bottom surface 27 of the main body side, making it easier to approach the surface of the substrate 7, and
The reduced pressure (suction) effect between the surface of the substrate 7 and the surface of the substrate 7 is also favorable.

The bottom surface is formed so that the bottom surface 27 on the main body side and the bottom surface 37 on the center member side are substantially flush with each other, or the bottom surface 37 on the center member side is slightly concave, and the bottom surface in the direction in which the air blown from the slit groove 23 flows, that is, on the main body side. The bottom surface 27 is formed into a planar shape so as to correspond to the substrate 7, and serves as a substrate suction surface.

On the other hand, a suction hole 3 is provided on the axis of the bottom surface 37 on the side of the central member.
3 is bored, and the suction hole 33 has a rectangular enlarged diameter part 33a at its upper end, and the small hole 3
4 to the enlarged diameter portion 33a and the ring-shaped slit groove 2.
It communicates with the flow path of No.3. A donut-shaped recess 35 is formed around the suction hole 33 on the bottom surface 37 on the side of the central member, and serves as a position regulating portion for the substrate 7.

That is, the small hole 34 and the slit groove 23 form a so-called fluid suction section.

Next, the operation of this embodiment will be explained.

First, when compressed air of 3 to 4 kg/cm ² is supplied from the compressed air inlet 22, it passes through the main hole 31 and enters the annular orifice 32 from the opening 31a on the downstream side, and then the diameter is reduced. Orifice groove 32
It is injected into the ring-shaped slit groove 23 from a.

In the ring-shaped slit groove 23, due to the flow velocity of the compressed air, clean outside air is sucked through the filter 24 from the auxiliary hole 25 communicating with the upstream side, and the air flow with increased flow rate flows downstream, and the outer periphery of the central member 30 is drawn. Air is sent outward from the outlet side opening 23a to the bottom surface 27 side of the main body side.

On the other hand, in the middle of the flow path of the ring-shaped slit groove 23, the enlarged diameter portion 33a of the suction hole 33 is inserted through the small hole 34.
Since the air is in communication with the main body side bottom surface 27, the outside air on the side of the bottom surface 37 on the center member side is also sucked through the suction hole 33 and is supplied to the bottom surface 27 on the main body side.

In this state, the measuring device is brought close to the surface of the substrate 7 while maintaining the parallel state between the surface of the substrate 7 and the bottom surface 27 of the main body, and when the gap distance d reaches approximately 0.2 to 0.8 mm, the ring-shaped slit is formed. Since the air sent from the groove 23 to the bottom surface 27 of the main body side is discharged outward within the gap d at a considerably high speed, negative pressure is generated between the gap d as in the previous embodiment. This creates a buoyant force on the substrate 7, and as a result, the substrate 7 floats up and is held close to the main body side bottom surface 27 through the high-speed air flow membrane in a non-contact state.

On the other hand, on the center member side bottom surface 37 side, the suction hole 3
3 sucks outside air from the center member side bottom surface 37 side, the air in the suction hole 33 and the donut-shaped recess 35 arranged around it is reduced in pressure, and becomes almost in a vacuum state, so that the substrate 7 The position is regulated and it can be held securely without slipping.

According to this embodiment, the substrate 7 is
In order to restrict the position of the holder, it is possible to hold the holder in a completely non-contact state, making it possible to provide an extremely preferable holding device.

"Effects of the Invention" As described above, according to the present invention, the flat member is held on the suction surface in a non-contact state via the high-speed fluid film, and the flat member is prevented from falling due to tilting of the suction surface from the horizontal position. Since the means for preventing this is formed by pressure action, even if the suction surface is tilted in any direction, the non-retaining member can be reliably held in a predetermined position in a completely non-contact state.

In addition, in the present invention, a recess is formed on the center region side located on the inner peripheral side of the suction surface, and a narrow passage communicating with the recess is opened to the air supply passage on the upstream side of the slit opening. Since the recess is placed under negative pressure by utilizing the suction action of the airflow flowing through the air supply passage, and the flat member sucked by the suction surface is held in position, the central area side and the peripheral area side are There is no need to provide separate air supply passages and suction passages on each side, and by simply ejecting high-speed airflow from the ring-shaped slit opening, the central area side can be automatically placed under negative pressure, and the pressure air pipes are A book is sufficient, and operability is greatly improved.

It has various effects such as , etc.

[Brief explanation of drawings]

1A and 1B relate to a comparative example of the present invention, with FIG. 1A being a perspective view and FIG. 1B being a front sectional view.
2A and 2B relate to an embodiment of the present invention;
Figure A is a front sectional view, and Figure 2B is a bottom view.

Claims (1)

[Claims] 1 Airflow is jetted toward the surface of the held member from a suction surface that can be approached with a certain gap on the flat plate-shaped held member surface, and buoyancy is applied to the held member by the suction force generated by the negative pressure of the high-speed fluid. In the device for holding a flat plate member, the suction surface and the held member are configured to be able to attract each other via a high-speed fluid film, wherein the bottom face facing the flat member is divided into a central area and a peripheral area. The peripheral edge side functions as a suction surface capable of suctioning the flat member through a high-speed fluid film, while the central area side has a recess. and opening a narrow passage communicating with the recess into an air supply passage upstream of the slit opening, and placing the recess under negative pressure by utilizing the suction effect of the air flow flowing through the air supply passage; A holding device for a flat member, characterized in that the flat member held by the suction surface is held in position.