JPH0373785B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to clean rooms used for various cleaning operations such as manufacturing LSIs and ultra-precision mechanical parts, or manufacturing chemicals. For the clean area, an air outlet is provided that blows out clean gas almost vertically downward in a laminar flow over the entire area, and a plurality of exhaust ports are each set around the periphery of the highly clean area in the indoor floor. The highly clean area, which is distributed so as to exhaust air according to the air volume ratio and where LSIs and other items required to maintain cleanliness are located, prevents dust from entering from around the high clean area, such as the low clean area where workers are located and the room walls. The present invention relates to a clean room which is prevented from being contaminated by gas by flowing clean gas from the air outlet to the peripheral exhaust port in the highly clean area.

[Conventional technology]

Conventionally, in clean rooms such as those mentioned above,
The exhaust air volume ratio of each floor exhaust port distributed around the periphery of the highly clean area is always maintained constant; for example, in the case of a clean tunnel as shown in Figure 5,
Q ₁ m ³ / from the first outlet 1 to the highly clean area A
h of clean air is blown out vertically downward in a laminar flow, and Q ₂ m ³ /h of clean air is blown out from the second outlet 4 to the low-grade clean area B as the worker area. In contrast, Q ₃ m ³ /h is supplied from the floor exhaust port 9 provided on the chamber wall 8 side in the periphery of the highly clean area.
In addition, Q ₄ m ³ /h (Q ₄ =Q ₂ +Q ₁ −Q ₃ ) is constantly exhausted from the floor exhaust ports 10 provided on the side of the low-grade clean area B, so that the room wall 8 This is to prevent contamination due to dust generated from the low-grade clean area B as well as contamination due to dust entering from the low-grade clean area B.

In other words, the supply air (Q ₁
The exhaust air volume ratio (Q ₃ :Q 1 −Q 3 ) of both the exhaust ports 9 and 10 to the air flow rate (Q 3 :Q ₁ −Q 3 ) with respect to the exhaust air volume (Q 3 ^: Q 1 −Q ₃ ) was always maintained constant.

In the figure, 2 and 5 are high-performance filters installed in the first outlet 1 and the second outlet 4, and 12 is a circulation fan that circulates exhaust air from the chamber wall side exhaust port 9 to the first outlet 1. , 7 is a supply air duct from the air conditioner, 14 is a return air/exhaust duct that returns the exhaust air from the low-grade clean area side exhaust port 10 to the air conditioner and exhausts a part of it to the outside of the system. 16 is a workbench for cleaning work installed in the highly clean area. (No literature can be provided.) [Problem to be solved by the invention] However, if there is no disturbance requirement for the airflow and the flow state of clean gas in the highly clean area is stable and steady, the cleanliness of the highly clean area is However, when a work object such as a worker or a work robot in a low-level clean area approaches the high-level clean area, the boundary between the high-level clean area and the low-level clean area may be damaged due to the presence of the nearby work body. In addition, a large amount of dust was generated from the working body, which caused the problem of contamination of the highly clean area.

On the other hand, if the amount of clean gas blown into the highly clean area and the exhaust air volume from the peripheral exhaust port are set large to increase the flow rate of clean gas within the highly clean area, If a large safety factor is set for the flow rate of clean gas within the area, contamination due to the close proximity of work objects to the highly clean area can be prevented, but it will require a large capacity air conditioner and air supply/exhaust system, and the blowing power will also be reduced. In addition, it is necessary to increase the flow rate of clean gas in the highly clean area only when the workpiece is in close proximity to the highly clean area. Although it is conceivable to perform control, it is unavoidable that equipment costs and operating costs will become expensive simply by suppressing the increase in blowing power.

An object of the present invention is to effectively prevent contamination of the highly clean area due to proximity of a workpiece while minimizing the flow rate of clean gas in the highly clean area.

[Means for solving problems]

The characteristic configuration of the clean room according to the present invention is that a plurality of exhaust ports are arranged around the room floor and are distributed around the room floor for a highly clean area where clean gas is supplied from the air outlet in a laminar flow almost vertically downward. A means for changing the exhaust air volume ratio is provided, and a sensor is provided in an indoor low-level cleaning area adjacent to the high-level cleaning area to detect whether or not a work body is in close proximity to the high-level cleaning area, and information from the sensor is provided. On the basis of the,
The exhaust air volume ratio of the exhaust port located on the side where the work body is close is set to be larger than the set air volume ratio when the work body is in the proximity state, and is returned to the set air volume ratio when the proximity state is canceled. In addition, a control means for automatically operating the air volume ratio changing means is provided, and its functions and effects are as follows.

[Effect]

In other words, when there are no workers, robots, or other work objects near the highly clean area, each of the peripheral exhaust ports is operated to exhaust air while maintaining the air volume ratio at the set ratio to achieve a high degree of cleanliness. By maintaining the clean gas flow state in the region at a predetermined steady state, the cleanliness of the highly clean region is reliably maintained with the smallest possible amount of clean gas flow within the region with a small safety factor.

Then, through automatic control based on sensor detection information, only when the workpiece is in close proximity to the highly clean area, the exhaust air volume ratio of the peripheral exhaust port on the side where the workpiece is close is adjusted to the above level. by changing the clean gas flow state in the highly clean area so that the clean gas flow rate in the portion of the highly clean area on the side of the adjacent work body is larger than that in the predetermined steady state. In other words, by increasing the flow rate of clean gas in the adjacent work body side part while replenishing the safety factor of the clean gas flow rate in the area other than the adjacent work body side part of the highly clean area, the work Prevent contamination of highly clean areas due to body proximity.

Therefore, even if a large safety factor is set for the overall flow rate of clean gas in the highly clean area and a large amount of clean gas does not flow, the cleanliness of the highly clean area can be maintained at a high level regardless of the proximity of the work body. be able to.

Although it is an additional matter, the exhaust air volume ratio of the exhaust port located on the side where the work body is close is increased to supplement the part of the highly clean area on the side of the work body that is close to the work body by the safety factor of the clean gas flow rate in other parts. When increasing the flow rate of clean gas on the side of the adjacent work body under such conditions, by appropriately setting the range of increase in the exhaust air volume ratio so that the replenishment amount does not exceed the safety factor, it is possible to The cleanliness of parts other than the work body side part is also reliably maintained unless unexpected disturbance requirements occur in that part.

〔Effect of the invention〕

As a result of the above, the cleanliness of the highly clean area can be maintained at a high level regardless of the proximity of work objects such as workers and work robots, thereby improving the quality of products such as LSIs and ultra-precision mechanical parts, and reducing the occurrence of defective products. Moreover, the amount of clean gas supplied to the high-speed clean area and the overall exhaust air volume from the exhaust port only need to be small at all times. The blowing power can also be greatly reduced, resulting in a clean room that is advantageous in terms of equipment costs and operating costs.

[First Embodiment] Next, a first embodiment of the present invention will be described based on the drawings.

Figures 1 and 2 show a so-called CREE tunnel that forms a manufacturing line for LSIs, ultra-precision mechanical parts, etc. In a tunnel-shaped room, a highly clean area A where manufactured products are located is located at both ends in the tunnel width direction. In addition, a low-grade clean area B serving as a worker passage area is arranged at the center in the width direction of the tunnel, and both areas A and B extend in the longitudinal direction of the tunnel.

A first air outlet 1 that blows out clean air almost vertically downward in a laminar flow over the entire area of the highly clean area A is configured with an opening on the discharge side of a high performance filter 2,
The first air outlet 1 and the first air supply chamber 3 therefor extend in the longitudinal direction of the tunnel above the highly clean area A within the tunnel-shaped room.

A second air supply chamber 6 equipped with a high-performance filter 5 that diffusely blows out clean air to the low-grade clean area B is distributed in the longitudinal direction of the tunnel and installed on the ceiling of the tunnel-shaped room. A feeder duct 7 from an air conditioner is connected to each of the first air supply chamber 3 and the second air supply chamber 6.

A first exhaust port 9 is provided at the lower end of the chamber wall 8 in contact with the highly clean area A, and a grid-shaped second exhaust port 10 is provided on the floor of the room corresponding to the low clean area B, extending in the longitudinal direction of the tunnel. The first exhaust port 9 and the first air supply chamber 3 are connected to a double-walled circulating air system so that the exhaust air from the first exhaust port 9 is circulated and supplied to the first air supply chamber 3. A circulation fan 12 is provided for the circulation air passage 11, and a part of the exhaust air collected from the second exhaust port 10 into the floor exhaust chamber 13 is sent to the air conditioner. The floor exhaust chamber 13 is connected to the return air/exhaust duct 14 so as to discharge return air or out of the system, and the remainder of the exhaust air collected in the floor exhaust chamber 13 is exhausted from the first exhaust port 9. The floor exhaust chamber 13 and the circulation air passage 11 are communicated via a bypass opening 15 so as to be circulated and supplied to the first air supply chamber 3 together with air.

In other words, while the clean air purified by the high-performance filter 2 is blown out and supplied to the highly clean area A in a downward laminar flow, a part of the clean air supplied to the highly clean area A is supplied to the highly clean area A. By exhausting through the first exhaust port 9 disposed on the floor on the side of the chamber wall 8 in the peripheral part, contamination of the highly clean area A due to dust generation from the chamber wall 8 is prevented, and the highly clean area By exhausting the remainder of the air supplied to A from the second exhaust port 10 placed on the floor on the low clean area B side of the circumference of high clean area A, together with the high quality clean air to low clean area B, The intrusion of dust from the low-level clean area B to the high-level clean area A is avoided to prevent contamination of the high-level clean area A due to the intrusion of dust.

In addition, the entire amount of exhaust air from the first exhaust port and a part of the exhaust air from the second exhaust port 10 are purified by the high performance filter 2 and circulated and supplied to the highly clean area A. In order to maintain the cleanliness of the highly clean area A, a large amount of clean air can be supplied to the highly clean area A, while reducing the amount of air processed on the air conditioner side as much as possible to make the equipment configuration more compact.

16 in the figure is a workbench for manufacturing LSI and ultra-precision mechanical parts.

Set air volume Q _A and Q _B from the air conditioner to the first air supply chamber 3 and the second air supply chamber 6, respectively.
of air conditioned air is continuously supplied, and exhaust air of a set air volume (Q _C = Q _A + Q _B ) is continuously supplied from the floor exhaust chamber 13 to the return air/exhaust duct 14, and further,
The entire ventilation equipment is configured and adjusted so that exhaust air with a set air volume Q _D is continuously supplied to the first air supply chamber 3 by the circulation fan 12.
An automatic damper 17 for changing the exhaust air volume is attached to the exhaust port 9, and by adjusting the opening degree of the damper 17, the first exhaust port 9 in the circulating exhaust air (Q _D = const) to the first air supply chamber 3 is attached. By changing the ratio of the amount of air exhausted from Q _E to the amount of air exhausted from the bypass opening 15 (Q _F = Q _D - Q _E ), the amount of air exhausted from the first exhaust port 9 to the tunnel-shaped room can be adjusted.
Q _E and the exhaust air volume from the second exhaust port 10 (Q _G = Q _F +
Q _C = Q _A + Q _B + Q _D - Q _E ), in other words, each exhaust air relative to the air supplied to the highly clean area A (Q _H = Q _A + Q _D = const) Exhaust air volume ratio of ports 9 and 10 (Q _E :Q _G −Q _B =Q _E :Q _H −
Q _E ) is configured to be changed by adjusting the opening of the automatic damper 17.

A footplate type sensor 18 is provided to detect when a worker or self-propelled work robot located in the low clean area B approaches the high clean area A, and based on the information from the sensor 18, the high A state in which no workers, etc. are close to clean area A (second
For reference to Figure A), the exhaust air volume ratio (Q _E /Q _H ), ((Q _H - Q _E )/Q _H ) of each exhaust port 9, 10 to the air supplied to the highly clean area A is determined in advance. Set steady ratio (Q _E /Q _H = K ₁ ), (Q _H − Q _E ) / Q _H =
K ₂ ) and in a state where the worker is close to the highly clean area A (see Figure 2 B), the exhaust air volume ratio of the second exhaust port 10 to the air blown to the highly clean area A ( _{Q H} −Q _E )/Q _H ) is set to _a value (K ₂
+△K ₂ ) and set the exhaust air volume ratio (Q _E /Q _H ) of the first exhaust port to a value (K ₁ - △K _{1 ) smaller than the steady ratio K 1 by} the set width △K ₁ . like,
A control device 19 that automatically operates the damper 17 to change the exhaust air volume ratio (Q _E :Q _H −Q _E ) of each exhaust port 9, 10 to the air blown and supplied to the highly clean area A.
is provided.

In other words, when there are no workers or the like near the highly clean area A, as shown in Figure 2A, the first exhaust port 9 located on the chamber wall 8 side with respect to the highly clean area A and the low clean area B and the second exhaust port 10 arranged on the side.
The clean air laminar flow state in the highly clean area A is maintained at the predetermined steady ratio K ₁ , K ₂ by exhausting while maintaining the respective exhaust air volume ratios to the air Q _H blown to the highly clean area A. By stably maintaining the steady state, the required flow rate Q _H of clean air in the highly clean area A is reduced as much as possible, while preventing both dust generation from the chamber wall 8 and dust intrusion from the low clean area B. In order to maintain the cleanliness level of highly clean area A at a high level with a predetermined safety factor for Sometimes, as shown in FIG. 2B, the second exhaust port 10 located on the side where workers etc. are close is set to the above-mentioned set steady ratio K ₂ to set the exhaust air volume ratio to the air Q _H blown into the highly clean area A. The clean air flow state in the highly clean area A is determined by applying exhaust action with K ₂ + △K 2 larger than (K 2 + ΔK ₂ ).
In other words, by changing the flow rate of clean air in the portion of the highly clean area A facing the low clean area B side to be larger than that in the predetermined steady state, in other words,
The clean air flow in the part facing the low clean area B side is supplemented by the safety factor of the clean air flow amount in the part facing the room wall 8 side of the high clean area A to the part facing the low clean area B side. By increasing the amount, the amount of clean air blown and supplied to the highly clean area A can be maintained, regardless of the occurrence of severe overflow due to the proximity of workers, etc., and the generation of a large amount of dust from nearby workers, _etc.
The cleanliness level of the highly clean area A is maintained while keeping it constant.

In addition, the exhaust air volume ratio of the second exhaust port 10 is increased, and the part of the high clean area A facing the low clean area B side is supplemented by the safety factor of the clean air flow rate in the part facing the chamber wall 8 side. In order to increase the flow rate of clean air facing the low clean area B side, the exhaust air volume ratio change width △K of the first and second exhaust ports 9 and 10 is made so that the replenishment amount does not exceed the safety factor. ₁ , △K ₂
is set, so that the second exhaust port 10
Even when the exhaust air volume ratio is increased, contamination of the highly clean area A caused by dust from the chamber wall 8 can be sufficiently prevented.

[Second Embodiment] Next, a second embodiment of the present invention will be described based on FIGS. 3 and 4.

Highly clean area A, where items required for cleanliness maintenance are located, is placed in the center of the clean room, and low clean area B, which serves as a work area, is placed around the highly clean area A within the clean room. An air outlet 1 is provided in the ceiling of the room to supply clean air purified by a high-performance filter 2 in a laminar flow vertically downward to the entire area, and an air outlet 1 is provided in the indoor floor on all four sides of the highly clean area A. The first to fourth exhaust ports 10A to 10D are arranged in a distributed manner, and the clean air flows from the air outlet 1 to each of the exhaust ports 10A to 10D, from the low clean area B to the high clean area A.
The cleanliness level of the highly clean area B is maintained at a high level by preventing dust from entering the area.

In the figure, 13 is an exhaust chamber communicating with each of the exhaust ports 10A to 10D, and 16 is a workbench on which items necessary for cleaning maintenance are placed.

Automatic dampers 17A to 17D are attached to each of the first to fourth exhaust ports 10A to 10D, and the automatic dampers 17A to 17D are attached to each of the first to fourth exhaust ports 10A to 10D, and
Infrared sensors 18A to 18D are provided on each of the four sides of the highly clean area A to detect whether or not a worker is close to the workbench 16.

Based on the information from these sensors 18A to 18D, when no worker is near the workbench 16 on any of the four sides of the highly clean area A (see Fig. 3A), In such a manner that the exhaust air volume of each of the first to fourth exhaust ports 10A to 10D is maintained at a uniform Q, and the worker is close to the workbench 16 on either side of the four peripheries of the highly clean area A ( (see Figure 3B), the exhaust air volume of the exhaust ports 10B to 10D located on the side where the worker is not close is reduced from the above-mentioned uniform state by the respective set air volume △Q, and the reduced set air volume △Q is reduced. A control device 19 is provided that automatically operates each of the automatic dampers 17A to 17D so as to increase the exhaust air volume of the exhaust port 10A located on the side near the worker from the uniform state by an amount 3ΔQ equal to the sum of the parts. There is.

In other words, the safety factor of the clean air flow amount in the part of the highly clean area A that is not close to the worker is replenished to the part that is close to the worker, and the part that is close to the worker is By increasing the flow rate of clean air at
This can be effectively prevented without increasing the amount of clean air supplied to the air.

In the above description, the case where the worker approaches the workbench 16 on the side where the first exhaust port 10A is located is shown, but for example, the worker approaches the workbench 16 on the side where the second exhaust port 10B is located. , the first, third, and fourth exhaust ports 10A, 1
The sensor 1 is configured to reduce the exhaust air volume of 0C and 10D and increase the exhaust air volume of the second exhaust port 10B.
Automatic control is performed based on information from 8A to 18D, and is configured so that it can be handled even when a worker approaches any of the four sides of the highly clean area A.

In addition, when a worker approaches the workbench 16 on two of the four sides of the highly clean area A, the exhaust air volume of the exhaust ports located on the other two sides is reduced by the set air volume ΔQ, respectively. The control device 19 is configured to increase the exhaust air volume of the exhaust ports located on the two sides closer to the operator by the set air volume ΔQ.

[Another example]

Next, other embodiments of the present invention will be listed.

The specific arrangement form of the plurality of exhaust ports 9 and 10 distributed around the periphery of the highly clean area A on the indoor floor is as follows:
Various configuration changes are possible depending on the cleaning work conditions, the form of the room, etc.

As a specific configuration for changing the exhaust air volume ratio between the peripheral exhaust ports 9 and 10, instead of applying the automatic damper as in the above-mentioned embodiment, various conventionally known types of air volume control configurations can be applied. These are collectively referred to as exhaust air volume ratio changing means 17.

As the sensor 18 for detecting whether the work body of the worker or the like is in close proximity to the highly clean area A, various types of contact or non-contact sensors can be applied.
Alternatively, substantially one sensor 18 may be used to detect both the presence or absence of a work object and the position of the work object.

A microcomputer is applied to configure the control means 19 that automatically operates the air volume ratio changing means 17 based on the information from the sensor 18,
Further, the specific configuration can be changed in various ways, such as by using a sequence circuit.

In addition, the exhaust air volume ratio in steady state of each of the exhaust ports 9 and 10 distributed around the circumference of the highly clean area A, and the exhaust air volume ratio of the exhaust ports 9 and 10 located on the side near the work body, respectively.
The exhaust air volume ratio increase width of 10 may be set appropriately.

The present invention can be applied to clean rooms of various shapes, and the specific use of the clean room is not limited.

[Brief explanation of drawings]

1 and 2 show a first embodiment of the present invention, in which FIG. 1 is a cutaway perspective view, and FIGS. 2A and 2B are enlarged sectional views showing clean gas flow conditions. 3 and 4 show a second embodiment of the present invention, and FIGS.
B is a sectional view showing the state of clean gas flow, and FIG. 4 is a schematic plan view. FIG. 5 is a partially schematic sectional view showing a conventional example. A...Highly clean area, B...Low clean area, 1...
Air outlet, 9, 10... Exhaust port, 17... Exhaust air volume ratio changing means, 18... Sensor, 19... Control means.

Claims (1)

[Claims] 1 For a highly clean area A in the room, an air outlet 1 is provided that blows out clean gas almost vertically downward in a laminar flow over the entire area, and a plurality of air outlets are installed around the periphery of the highly clean area A in the indoor floor. This is a clean room in which exhaust ports 9 and 10 are arranged in a distributed manner so that the exhaust ports 9 and 10 act as exhaust air at a set air volume ratio, respectively.
A sensor 18 for detecting whether or not a work body is in close proximity to the high clean area A in an indoor low clean area B adjacent to the high clean area A. Based on the information from the sensor 18, the exhaust air volume ratio of the exhaust ports 9 and 10 located on the side where the work body is close to is set to be higher than the set air volume ratio when the work body is in the proximity state. Control means 1 for automatically operating the air volume ratio changing means 17 so as to increase the air volume ratio and return it to the set air volume ratio upon release of the proximity state.
Clean room with 9 rooms.