JPH04196532A - Sealing mechanism for driving equipment - Google Patents

Abstract

PURPOSE:To surely prevent outside air from permeating into an inner cover even if it permeates, by pressurizing the inside of the inner cover covering a driving equipment by a pressurizing equipment, keeping the inside in a positive pressure state, exhausting the inside of an outer periphery cover by an exhaust system, and keeping the inside in a negative pressure state. CONSTITUTION:The inside of an inner cover 88 covering a driving equipment is pressurized by a pressurizing equipment 98, and kept in a positive pressure state. The inside of an outer periphery cover 90 covering the external side of the inner cover 88 is exhausted by an exhaust system 100, and kept in a negative pressure state. On account of the difference between the pressure inside the inner cover 88 and the pressure inside the outer periphery cover 90, the atmosphere inside the inner cover 88 is apt to escape to the inside of the outer periphery cover 90. Dust generated inside the inner cover 88 is compulsorily made to flow into the inside of the cover 90 and discharged outword. When outside air permeates into the inside of the cover 90, it is discharged and can not permeate into the inner cover 88. When the atmosphere inside the inner cover 88 escapes to the cover 90 side, it does not leak outside the cover 90, because the inside of the cover 90 is exhausted by the exhaust system 100. Thereby the dust and like in the inside are not discharged outward.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to a sealing mechanism for a drive device, and is particularly suitable for application to a device that does not like dust and needs to be treated with chemicals, etc. This invention relates to a sealing mechanism for a drive device.

(Prior Art) An example of a device that does not like dust and needs to perform chemical treatment or the like is a cleaning device in a semiconductor wafer manufacturing device.

The cleaning equipment in this semiconductor wafer manufacturing equipment is designed to perform the cleaning process in a dust-free clean atmosphere in consideration of the effects on the semiconductor wafers, and also performs ammonia treatment, water washing treatment, hydrofluoric acid treatment, etc. on semiconductor wafers. The cleaning process is carried out.

Therefore, conventional cleaning equipment is equipped with multiple processing tanks such as an ammonia processing tank, a water washing processing tank, a hydrofluoric acid processing tank, etc., and semiconductor wafers are transported to each processing tank using a device using a drive device such as a transport device or a boat. I was trying to transport and supply it.

(Problems to be Solved by the Invention) In the cleaning device in the conventional semiconductor wafer manufacturing equipment described above, a drive device is used for the transport device, boat, etc. that transports and supplies semiconductor wafers to each processing tank. The drive equipment is a source of dust that generates dust during operation, and the dust generated from this drive equipment contaminates the clean atmosphere mentioned above, and in particular, it causes impurities to adhere to semiconductor wafers, which have become increasingly finely processed in recent years. However, there was a problem that the product yield of semiconductor wafers could be lowered.

Further, as described above, the cleaning treatment apparatus uses ammonia for the cleaning treatment, and when this ammonia enters the drive device, there is a problem in that it corrodes the drive device.

However, since the drive device is connected to a movable part, it has not been possible to completely hermetically seal the drive unit.

Therefore, the present invention allows for the existence of a mechanical gap between the inside of the drive device and the outside, which is a source of dust generation, but prevents dust from leaking from inside the drive device to the outside, and further improves the atmosphere outside the drive device. It is an object of the present invention to provide a sealing mechanism for a drive device that does not penetrate into the drive device and corrode the inside of the drive device.
This is a problem to be solved.

[Structure of the Invention (Means for Solving the Problems) A sealing mechanism for a drive device according to the present invention includes an inner cover provided to cover a drive portion of the drive device, and an inner cover provided to cover the outside of the inner cover. A pressurizing device that maintains the inside of the inner cover in a positive pressure state; and an exhaust device that exhausts the inside of the outer peripheral cover and maintains it in a negative pressure state.

(Function) The sealing mechanism of the drive device of the present invention having the above-mentioned configuration uses a pressure device to pressurize the inside of the inner cover that covers the drive device to maintain a positive pressure state, and the outer cover that covers the outside of the inner cover. By evacuating the inside with an exhaust device and maintaining a negative pressure state, the atmosphere inside the inner cover will always try to escape to the inside of the outer cover due to the pressure difference between the inner cover and the outer cover. Become. For example, the dust generated within the inner circumferential cover is forced to flow into the outer circumferential cover to exhaust the generated dust.

On the other hand, even if outside air were to enter into the outer circumferential cover, it would be exhausted and the inner cover would be in a state 1Q where no air could enter.

Also, even if the atmosphere inside the inner cover escapes to the outer cover side, the inside of the outer cover is exhausted by the exhaust system, so it will not leak to the outside of the outer cover, and the dust inside will come out. Never. In this case, since the outside air that has entered the outer circumferential cover is also exhausted by the exhaust device, intrusion into the inner cover is further prevented.

(Example) Hereinafter, an example in which the sealing mechanism of the drive device of the present invention is applied to a cleaning device in a semiconductor wafer manufacturing apparatus will be described with reference to the drawings.

In FIG. 1, the semiconductor wafer cleaning apparatus of this embodiment is constructed by combining three cleaning processing units IO, 12.degree. 14. A loader 16 for processing wafers is connected to the processing unit 10 on the carry-in side, and an unloader 18 for processed wafers is connected to the processing unit 14 on the carry-out side. An underwater loader 2o included in any of the three units is disposed between the processing units 12 and 14. The arrangement order may be changed. In this example, the settings are made according to a predetermined cleaning processing program.

The cleaning processing unit 1o on the carry-in side is provided with a rotating transfer arm 24 for transferring semiconductor wafers 22 at the center position, and around the rotation transfer arm 24 and the front of the loader 16.
Two cleaning tanks 26 and 28 are arranged on the left side of each tank. In this embodiment, the cleaning tank 26 is used as a chemical treatment tank for ammonia treatment, and the cleaning tank 28 is used for cleaning with water.
It is used as a rinsing (QDR) treatment tank.

The central cleaning processing unit 12 has underwater loaders 20 positioned on both left and right sides around a rotary transfer arm 24 disposed at the center, and two cleaning processing tanks 3 each at the front and rear positions between them.
o, 32 are arranged. In this embodiment, the cleaning treatment tank 3o is used as a chemical treatment tank for performing hydrofluoric acid treatment, and the cleaning treatment tank 32 is used as a water washing overflow treatment tank.

The cleaning processing unit 14 on the output side has a cleaning tank 34 arranged on the front side of the unloader 18 around the rotary transport arm 24 arranged at the center position, and
A drying treatment tank 36 is arranged on the right side of the drying tank 36. In this embodiment, the cleaning treatment tank 34 is used as a final rinse tank.

In addition, each of the above cleaning treatment tanks 26.28, 30°32.34
As shown in FIG. 4, the underwater loader 20 and the drying tank 36 are placed in a case 40 each having an opening 38 for loading and unloading the semiconductor wafers 22. A shutter 44 for opening and closing the opening 38 is disposed in the opening 38, and an air blowing part (not shown) is provided above the opening in the case 40.
The atmosphere between the inside of the case 40 and the outside is cut off by an air curtain blown out from the air blowing section. In this case, air is sucked in from the lower part of the case 40 and the pressure inside the case 40 is set to be slightly lower than the atmospheric pressure to prevent the atmosphere inside the case 40 from leaking to the outside.

The loader 16 includes two carriers 48 as shown in FIG.
25 semiconductor wafers 22 each placed on the
After the orientation flats of the semiconductor wafers 22 are aligned by a so-called orientation flat alignment mechanism 49, the semiconductor wafers 22 on the two carriers 48 are pushed up by a push rod 51.
The push-up rods 51 are pushed upwards so that the push-up rods 51 are brought together, and in this state, only the 50 semiconductor wafers 22 are scooped up by the rotary transfer arm 24 on the carry-in side. The unloader 18 has a mechanism similar to that of the loader 16, and is configured to perform processing in the reverse order of that of the loader 16.

As shown in FIG. 3, the rotary transfer arm 24 has a multi-jointed arm body 50 that is horizontally rotatable and extendable.
It has a wafer fork 52 for mounting the semiconductor device 22,
50 without carrier 48 on this Unihafork 52
Loader 16, cleaning treatment tank 26°28, 30, 32, 34, underwater loader 20
, the semiconductor wafer 22 is transferred between the drying tank 36 and the unloader 18.

Specifically, the wafer fork 52 supports the semiconductor wafer 22
The loader 16,
Between the unloader 18, the semiconductor wafer 22 is picked up from the push-up rod 51 that moves up and down between the two support rods 54, or the semiconductor wafer 22 is passed to the push-up rod 51. , also underwater loader 20
, the cleaning processing tanks 26, 28, 30, 32, 34, and the drying processing tank 36, by moving up and down a wafer storage boat 56, which is provided exclusively for each tank to store objects to be processed, The semiconductor wafers 22 are received from the dedicated boat 56 or the semiconductor wafers 22 are transferred to the boat 56.
The receiver is supposed to pass it on.

The boat 56 dedicated to each tank has three parallel support rods 58 having a large number of support grooves for placing and positioning the semiconductor wafers 22.
, and is supported by the arm 60 so as to be vertically movable as described above. Support these three M! 58 are two support rods 5 of the wafer fork 52 of the rotary transfer arm 24.
It is provided in a position that does not interfere with the semiconductor sea urchin 22 in the vertical direction, and is arranged along the outer shape of the semiconductor sea urchin 22. Also,
This boat 56 is designed to directly place and position the semiconductor wafer 22, and the carrier 48 is not used. Then, the wafer fork 52 of the rotary transfer arm 24
A semiconductor wafer 22 is placed on top, and this wafer fork 5
When the arm 60 is extended and the boat 56 is raised with the semiconductor wafers 22 entering each tank through the opening 38, the semiconductor wafers 22 on the wafer fork 52 are placed on the boat 56. Conversely, semiconductor wafers 22 are placed on the boat 56.
The semiconductor wafers 22 on the boat 56 are lifted by raising the boat 56 with the semiconductor wafers 22 placed on the boat 56, inserting the wafer fork 52 of the rotary transfer arm 24 under it, and lowering the boat 56.
is placed on the sea urchin fork 52 of the rotary transfer arm 24.

Further, the arm 60 that supports the boat 56 is a driving source that moves up and down, and is a part that generates dust.
Moreover, since it is installed in a tank that handles chemicals, there is a risk of corrosion due to the chemicals. Therefore, a sealing mechanism is used to prevent dust from leaking to the outside, and to prevent the chemical atmosphere inside the tank from entering the arm 60. This is to prevent corrosion.

Specifically, the arm 60 consists of a fixed side part 62 and a movable side part 64 as shown in FIG. 5, and by moving the movable side part 64 up and down with respect to the fixed side part 62,
An arm body 66 for supporting the boat 56 provided at the top of the movable side part 64 is moved up and down.

Next, details of the sealing mechanism will be explained with reference to FIG. 6.

The fixed side part 62 seals a motor 72 in a housing 70 having a support base 68 on the upper surface, and a screw shaft 74 connected to the motor 72 is erected on the support base 68. Furthermore, three guide shafts 76 are arranged in parallel at equal intervals around the screw shaft 74. Note that the other ends of the screw shaft 74 and the guide shaft 76 are supported by a fixed plate 78.

The movable side portion 64 includes a nut 80 that is screwed onto the screw shaft 74, and a first movable plate 82 that is integrated with the nut 80 and is movably fitted onto the screw shaft 74 and the guide shaft 76. and three equally spaced parallel slide shafts 84, one end of which is attached to the first movable plate 82 and the other end of which is slidable through the fixed plate 78, and the fixed plate 78. It includes a second movable plate 86 that supports the other end of the slide shaft 84 passing through it, and is movable up and down along the screw shaft 74 and guide shaft 76.

Further, the arm main body 66 is mounted on the movable plate 86 of 's2.

A cylindrical inner cover 8 is placed on the support base 68 of the fixed side part 62 to cover the screw shaft 74, guide shaft 76, slide shaft 84, etc. which are the vertical drive parts.
8 is attached, and a cylindrical outer circumferential cover 90 that covers the outside of the inner cover 88 is attached to the second movable plate 86 side of the movable side portion 64. Furthermore, an outer cover 92 that covers the outer side of the outer cover 90 is attached to the inner cover 88, and these inner cover 88, outer cover 90, and outer cover 92 are each configured with a gap between them. It serves as a heavy cover. Note that the upper end of the inner cover 88 is attached to the fixing plate 78.
It is sealed with a sealing plate 94 placed above. Moreover, the space between the sealing plate 94 and the slide shaft 84 and the space between the sealing plate 94 and the outer peripheral cover 90 are each sealed with a sealing material 96.

Further, a pressurizing device 98 is connected to the inner cover 88 to pressurize the inner cover 88 and maintain the inner cover in a positive pressure state. This pressurizing device 98 is used to prevent gas such as ammonia from entering the inner cover 88 and corroding the internal mechanism. , support base 6
Pressure is supplied into the inner cover 88 from part 8. Therefore, this positive pressure atmosphere prevents gas such as ammonia from entering into the inner cover 88.

Further, an exhaust device 100 is connected to the lower side between the inner cover 88 and the outer cover 92 to exhaust air between the outer cover 90 and the inner cover 88 and between the outer cover 90 and the outer cover 92. I have to. In this way, the exhaust is performed so that even if gas such as ammonia or dust that enters from the upper end side of the outer cover 92 enters between the outer cover 90 and the outer cover 92, the inner cover 88 and the outer cover 92 This is to prevent it from entering between the inner cover 88 and the outer cover 90, and even if it does enter between the inner cover 88 and the outer cover 90, the inside is in a negative pressure state, so the exhaust system 1
It is set to be ejected by 00. Note that by employing this exhaust device 100, it is possible to sufficiently cope with the gas permeability of each of the above-mentioned covers to some extent.

In this way, the inside of the inner cover 88 that covers the drive device is pressurized by the pressurizing device 98 to maintain a positive pressure state, and the inner cover 88
By evacuating the inside of the outer circumferential cover 90 that covers the outside with the exhaust device 100 and maintaining it in a negative pressure state, the atmosphere inside the inner cover 88 is It is always in a state where it tries to escape to the inside of the outer peripheral cover 90. For example, dust generated within the inner cover 88 is forced to flow into the outer cover 90 to exhaust the dust. On the other hand, even if outside air were to enter into the outer circumferential cover 90, it will be exhausted and will not be able to enter into the inner cover 88.

Further, even if the atmosphere inside the inner cover 88 escapes to the outer cover 90 side, the inside of the outer cover 90 is
Since the air is exhausted by the air, there is no leakage to the outside of the outer circumferential cover 90, and internal dust and the like will not come out. In this case, the outside air that has entered the outer circumferential cover 90 is also exhausted by the exhaust device 100, so that intrusion into the inner cover 88 is further prevented.

Furthermore, in this embodiment, when exhausting air using the exhaust bag r1100, a sensor (not shown) for detecting the chemical atmosphere is provided to detect the internal state, and depending on the state, the pressurizing device 98 and The exhaust system 100 is controlled to maintain an optimum state.

Note that there is a space between the sealing plate 94 and the second movable plate 86 in order to prevent the inside from being sealed so that a pumping action occurs when the arm 60 is moved and ammonia gas etc. are sucked. , an air introduction hole 102 is provided to allow the introduction of some air.

In the above embodiment, the case where 50 semiconductor wafers 22 placed on two carriers 48 are processed at one time has been described, but this is not limited to this example. 22 may be processed at once.

Furthermore, the three processing units 10, 12, and 14 may be combined, or the number of combinations may be changed arbitrarily.

Furthermore, in the above embodiment, an example was explained in which the sealing mechanism of the present invention was applied to the arm 60 that moves the boat of each processing tank up and down, but the present invention can also be applied to various drive devices having a drive unit such as a transfer arm. It is possible to apply a sealing mechanism.

[Effects of the Invention] As explained above, the sealing mechanism of the drive device of the present invention uses a pressure device to pressurize the inside of the inner cover that covers the drive device to maintain a positive pressure state, and also to keep the outside of the inner cover in a positive pressure state. Because the inside of the outer cover was evacuated using an exhaust device to maintain a negative pressure state, there was a difference between the pressure inside the inner cover and the pressure inside the outer cover, and the atmosphere inside the inner cover was always inside the outer cover. Even if the air tries to escape and the outside air gets into the outer cover, it is possible to reliably prevent the air from getting into the inner cover.

In addition, even if the atmosphere inside the inner cover escapes to the outer cover side, the inside of the outer cover is exhausted by the exhaust device, so it will not leak to the outside of the outer cover, and the dust inside will come out. It has the effect of being able to reliably prevent this.

Furthermore, even if outside air enters the outer circumferential cover, it is reliably exhausted by the exhaust device, so that it is possible to further prevent outside air from entering into the inner cover.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the overall configuration of a cleaning device according to an embodiment of the present invention, Fig. 2 is a plan view showing the loader portion of Fig. 1, and Fig. 3 is a plan view showing the loading side processing of Fig. 1. An enlarged view showing the unit, Figure 4 is a perspective view showing the state of each cleaning tank, underwater loader, and drying tank, Figure 5 is a side view showing the state of the arm and boat, and Figure 6 is the arm seal mechanism. FIG. 7 is a sectional view showing the state of each shaft. 60...Arm, 66...Arm body, 74...
Screw shaft, 76... Guide shaft, 88... Inner cover, 90...
...Outer circumferential cover, 92... Outer cover, 98... Pressurizing device, 100... Exhaust device. Agent Patent attorney Inoue - (1 other person) Figure 2 22. 22 Figure 4 Figure 5

Claims (1)

[Scope of Claims] An inner cover provided to cover a drive portion of a drive device, an outer cover provided to cover an outside of the inner cover, and a pressurizing device for maintaining a positive pressure state inside the inner cover. A sealing mechanism for a drive device, comprising: an exhaust device that exhausts the inside of the outer circumferential cover to maintain a negative pressure state.