JPH05146688A - Clean room - Google Patents

Abstract

PURPOSE:To enhance clearness of air in a clean room than a conventional method. CONSTITUTION:Instruments 27a, 27b are provided in the space 40 between the floor face 20a of a clean room 20 and a slab 25. A return duct 42 formed of a stainless plate is formed in the space 40 by being partitioned for the space in which the instruments are provided. A machinery room 41 is relatively formed in the part of the space 40 exclusive of the return duct 42. Many holes are bored in the upper plate part 42c of the return duct 42 and an aperture part 25a is formed in the slab 25. The air passed through the interior 23 is passed through the gap 48 between an assemble floor 24 and the slab 25 and introduced into the return duct 42. The clean room is constituted so that the circulated air is prevented from being brought into contact with the instrument and the pipeline of a backup system 27 in the machinery room 41.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clean room,
In particular, it relates to a clean room having a high degree of cleanliness required for semiconductor manufacturing and the like.

With the recent high density and high integration of semiconductors,
For clean rooms used for semiconductor manufacturing,
There is a need for a technology to stably circulate and air-condition clean air.

[0003]

2. Description of the Related Art FIG. 4 is a block diagram showing an example of a conventional clean room.

In the figure, 2 is a filter at the final stage of the air supplied to the room 3, 4 is an assemble floor which is constructed by laying a plurality of panels and is selectively removable, and 5 is installed in the room 3. A slab that is a floor plate that supports the manufacturing equipment 6, a backup system for the manufacturing equipment 6, an air conditioner 8 in which a blower is installed, 9 is a space under the slab, 10 is a ceiling space, 11a, 11b are ducts on the inlet side and the outlet side of the air conditioner 8, respectively. Between the assembly floor 4 and the slab 5, a plurality of manufacturing apparatuses 6 are provided, and between the manufacturing apparatus 6 and the backup system 7.
A gap is formed to some extent in order to arrange the pipe and the wiring for connecting the and. The floor surface 1a, the ceiling surface 1b, the side surface 1c, and the back surface 5a of the slab 5 of the clean room 1
Each has a structure in which dustproof paint is applied to concrete or new building material.

The air whose temperature and humidity have been adjusted as well as the particles and dust of a certain size being removed by the air conditioner 8 passes through the duct 11b and the ceiling space 10 and the filter 2
Then, fine particles of dust are removed by the filter 2 and supplied to the room 3. The supplied air flows downward in the room 3 and passes through the assemble floor 4 having a large number of ventilation holes and the slab 5 having a large number of openings 5b for the pipes 12 and the like. , Enters the space 9 below the slab in which the backup system 7 is provided, and returns to the air conditioner 8 again through the duct 11a. With such a circulation path, the room 3 is always filled with air from which fine particles of dust are removed.

[0006]

In the case of the conventional clean room 1 having the above-mentioned structure, since each device of the backup system 7 is provided in the space 9 under the slab, the paint or the liquid agent applied to the surface of each device is removed. A harmful gas that volatilizes, such as phthalic acid ester, which adversely affects the cleaning of the air is mixed into the air passing through the space 9 below the slab, dust generated from each device of the backup system 7, and the surface of each device. There was a problem that dust and dirt collected in the air would get mixed into the air. Similarly, in the space 9 under the slab, the harmful gas volatilized from the dust-proof paint on the wall surface is also stored in the space 9 under the slab.
In the above, there is a problem in that it mixes with the circulating air or dust and dirt accumulated on the surface of the concrete or the new building material having a rough surface is mixed with the air. As described above, in the configuration of the conventional clean room 1, there is a limit to the improvement of the cleanliness of air, and it has been difficult to meet the high cleanliness currently required.

Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a clean room in which the cleanliness of air is further improved by improving the structure of the space under the slab.

[0008]

In order to achieve the above object, the present invention comprises a slab, which is a floor plate, laid at a position of a predetermined height from the floor, and the floor and the slab are In a downflow type clean room in which equipment necessary for indoor operations is installed in the space between, a return duct that collects the air that has passed through the room and returns the air to the blower inlet side is provided in the space. The inner surface of the return duct is made highly clean while being provided.

[0009]

In the present invention, by providing the return duct in the space between the floor surface and the slab, the equipment is installed in the space and the section through which air does not flow is relatively configured. For this reason, the air that has passed through the room is returned to the blower inlet side without contacting the equipment in the compartment, and harmful gas and dust are mixed into the air by contacting the equipment as in the past. Is prevented.

Further, by making the inner surface of the return duct highly clean, the harmful gas is prevented from volatilizing from the inner surface of the return duct, and the harmful gas is prevented from being mixed into the air as in the conventional case. In addition, dust and dirt are not collected on the inner surface of the return duct, and dust and dirt are prevented from being mixed into the air in the return duct.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view showing the construction of an embodiment of the clean room according to the present invention, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. 3 is taken along line III-III in FIG. A sectional view is shown.
Note that FIG. 1 shows a cross-sectional portion taken along the line II in FIG. The clean room 20 of this embodiment is an example of a clean room used in the semiconductor manufacturing process.

In each figure, 22 is a HEPA (High Efficienc
y Particulate Air-filter) Indoor 2 called a filter
Ultra-high-performance filter in the final stage of air supplied to 3
4 is an assemble floor that is constructed by laying a plurality of panels and is selectively removable, and 25 is an interior 23
A slab that is a floor plate that supports the manufacturing equipment 26 for semiconductor manufacturing installed in the device, 27 is a backup system for the manufacturing equipment 26, 28 is an air conditioner having a blower 28a installed therein, and 29 is a suction device for absorbing dust. It is a filter containing an adsorbent. The backup system 27 is the vacuum pump 2
7a and a plurality of other devices 27b, piping, wiring, and the like. Although a plurality of manufacturing equipments 26 are installed in the room 23, only one manufacturing equipment 26 is shown as a representative in FIGS. 1 and 2 for convenience of illustration.

The slab 25 is made of a dustproof concrete plate, and is laid by being supported at a predetermined height position from the floor surface 20a of the clean room 20 by the columns 30. Further, the assemble floor 24 has a large number of holes for allowing air to pass through each panel, and a gap 48 is formed between the struts 31 and the slab 25 so that the manufacturing equipment 26 is not arranged on a plane. It is laid in the part. The gap 48 between the assembly floor 24 and the slab 25 is
As described above, it is provided for arranging the pipes and wirings for connecting between the plurality of manufacturing apparatuses 26 or for connecting the manufacturing apparatus 26 and the backup system 27. Also, H
The EPA filter 22 is the ceiling surface 20 of the clean room 20.
It is supported from b by hanging metal fittings (not shown).

In a space 40 between the floor surface 20a and the slab 25, return ducts 42 and 43 for collecting the air passing through the room 23 and flowing the air to the air conditioner 28 side are provided. By providing the return ducts 42 and 43, the backup system 2 is provided in the space 40.
7 and piping 3 connected to the backup system 27 or the manufacturing equipment 26 from the outside of the clean room 20
2, the equipment room 41 corresponding to the section in which the wiring 33 and the like are arranged is relatively independently configured. Here, the return ducts 42 and 43 are formed of stainless steel plates into elongated duct shapes. Therefore, as shown in FIGS.
The space 40 is formed by forming return ducts 42 and 43 with a stainless plate in a portion directly below the slab 25 of 0.
Are separated and separated by a stainless plate into the return ducts 42 and 43 and the equipment chamber 41 other than the return ducts 42 and 43.

The four side plates 42a, 43a and the bottom plates 42b, 43b of the return ducts 42, 43 are made of stainless steel plates having smooth surface roughness on the inner surface of the duct, and the upper plates 42c, 43c. Uses a stainless steel plate in which a large number of holes having smaller diameters are formed in addition to the above-mentioned stainless steel plate whose surface roughness on the inner surface side of the duct is smoothly processed. In addition, the return ducts 42,
A slender large opening 25a corresponding to the shape of 43 is formed, so that the upper plate portions 42c, 43c of the return ducts 42, 43 are exposed in the opening 25a. For this reason, the air above the slab 25 is
The structure is such that it can be inserted into the return ducts 42 and 43 through a and a large number of holes provided in the upper plate portions 42c and 43c.

At the outlet side portions of the return ducts 42, 43, dampers 44, 45 for adjusting the passage flow rate are provided with drive devices 44a, 45a, respectively, and the amount of air entering the return ducts 42, 43 respectively. By adjusting, the clean state of the room 23 can be set to a desired state. For example, when the manufacturing equipments 26 that require high cleanliness are concentrated on the return duct 43 side, the damper 44 is set to the closed side and the damper 45 is set to the open side so that the room 2
3 can be an efficient cleanliness distribution.

The adsorbent-containing filter 29 and the air conditioner 28 are individually provided in the return ducts 42 and 43, respectively. Therefore, some vertical ducts 46a are respectively provided between the outlets of the return ducts 42 and 43 and the two adsorbent-containing filters 29, and the outlet sides of the two air conditioners 28 are A duct 46b extending in the vertical direction is provided so as to be connected to the outlets of the two air conditioners 28. Furthermore, the ceiling surface 20b and the HEPA
A ceiling space 47 in which air flows between the filter 22 and the filter 22.
Is provided. Therefore, the duct 46b on the outlet side of the air conditioner 28 has a structure in which the air from the two air conditioners 28 is merged and uniformly flowed into the ceiling space 47.

Further, in FIG. 1, the duct 46a is provided with an outside air introducing portion 51 for introducing new outside air into the circulating air system with a filter 51a at the tip portion thereof, and the outside air introducing portion of the clean room 20. An air discharge portion 52 is provided on the opposite side of 51. By introducing the outside air little by little to the circulating air, the progress of pollution of the circulating air can be suppressed at a certain point.

Next, the flow path of air in the clean room 20 having the above structure will be described.

When the air conditioner 28 is operated, the air in the clean room 20 is circulated by the blower 28a in the device. First, the air in which the particulate dust is adsorbed and removed to some extent by the adsorbent-containing filter 29 is adjusted in temperature and humidity to a predetermined value in the air conditioner 28, and is sent to the duct 46b. Here, the air sent from the two air conditioners 28 merges in the duct 46b as described above and flows into the ceiling space 47 (arrow A). Then, the air passes through the HEPA filter 22 to remove considerably fine particles up to a particle size of about 0.3 μm to improve the cleanliness, and is sent to the room 23 (arrow B). HE in room 23
Flows downward from the PA filter 22 where the assemble floor 24 is provided (downflow method). This downflow prevents dust and the like existing in the room 23 from floating in the room 23.

The air that has reached the assemble floor 24 passes through a large number of holes formed in the assemble floor 24 and enters the gap 48 between the assemble floor 24 and the slab 25 (arrow C). Then, the liquid flows horizontally in the gap 48 toward the return ducts 42 and 43 which are located at the substantially shortest distance (arrow D). The air that has flowed through the gap 48 and reached the return ducts 42 and 43 is, as described above, the opening 25 a of the slab 25 and the return duct 4.
It passes through the holes formed in the upper plate portions 42c, 43c of the reference numerals 2, 43, and enters the return ducts 42, 43 (arrow E). Here, the opening 25a is formed in the slab 25.
In addition, a large number of openings 25b for inserting pipes and wirings connecting the manufacturing equipment 26 and the equipment room 41 are provided, but the equipment room 41 is provided with no openings other than the opening 25b. Since there is no return duct 42, 43
Since the internal pressure is pulled by the blower 28a and is lower than the internal pressure of the equipment chamber 41, the air flowing through the gap 48 does not flow into the equipment chamber 41 from the opening 25b, and the entire amount returns. It flows into the ducts 42 and 43.

Then, the inside of the return ducts 42 and 43 flows toward the outlet side on the side of the duct 46a (arrow F), and finally the outlets of the return ducts 42 and 43 pass through the ducts 46a and the respective adsorbent-containing filters 29. And air conditioner 2
8 is inhaled again (arrow G).

Part of the air that has entered the space 48 below the assemble floor 24 from the room 23 is discharged from the air discharge portion 52 to the outside of the clean room 20 (arrow H), and the air passes through the duct 46a. Sometimes, the discharged outside air is introduced from the outside air introduction part 51 (arrow I).
A damper may be provided in either the outside air introducing portion 51 or the air discharging portion 52, and the amount of outside air introduced into the circulating air system may be adjusted by the damper.

As described above, the clean room 2 of this embodiment
In 0, the air that has passed through the room 23 does not flow into the equipment room 41, and all of the air is returned to the return ducts 42 and 43.
And is discharged again to the air conditioner 28 side. That is, since the circulating air is prevented from coming into contact with each device of the backup system 27 as in the conventional case, harmful gas that adversely affects the cleaning of the air volatilized from the paint or liquid applied to the surface of each device is generated. It is prevented that the circulating air is mixed, and that the dust and dust generated from each device of the backup system 27 and the dust and dust collected on the surface of each device are mixed into the circulating air.

The return ducts 42 and 43 are made of a stainless steel plate whose surface has a smooth surface roughness as described above, and have a highly clean inner surface on which no paint or the like is applied. It is configured to have. Therefore, as in the conventional case, harmful gas is volatilized from the painted wall surface of the slab lower space 9 and mixed into the circulating air,
Dust and dust are prevented from collecting on the wall surface of the space 9 below the slab and mixed into the circulating air.

As described above, according to the configuration of the present embodiment, it is possible to prevent harmful gas and dust from being mixed into the circulating air in the circulation path through which the air flowing in the room 23 is returned to the air conditioner 28. Therefore, the air cleanliness of the clean room 20 can be improved more stably than in the conventional case. In particular, by preventing the volatilization of harmful gas into the air, it is possible to make the air cleaning which has conventionally been limited to the removal of fine particles in the air to be a molecular level cleaning. It is significantly improved compared to the past. As a result of the stable improvement of the air cleanliness as described above, the efficiency of semiconductor manufacturing performed in the room 23 is improved. Furthermore,
Since the amount of dust and dust to be adsorbed by the adsorbent-containing filter 29 is reduced, the life of the adsorbent is extended and the running cost of the clean room 20 is greatly reduced.

The return ducts 42 and 4 of this embodiment are also provided.
3, the upper plate portions 42c, 43c are the other side plate portions 42a, 43c.
It has a structure that can be easily removed from the portion formed by a and the bottom plate portions 42b and 43b. Therefore, by removing the upper plate portions 42c and 43c and regularly cleaning the inner surfaces of the return ducts 42 and 43, the inner surfaces of the ducts are kept highly clean, and the above-described effect of improving the air cleanliness is continued for a long time. be able to.

Further, since the circulating air does not flow in the equipment room 41, most of the floor surface 20a and the side surface 20c constituting the machine room 41, the backup system 27 in the equipment room 41, the piping 32, and the wiring 33 are further provided. Dust-proofing is not required on the surface of such as. Therefore, the clean room 20
When constructing, the construction cost can be reduced.

In this embodiment, as shown in FIGS. 1 and 2, the lower portions of the return ducts 42 and 43 are connected to the outside of the clean room 20 and the backup system 27 and the manufacturing equipment 26 such as piping 32 and wiring 33. It was used as a piping zone. Therefore, the equipment room 41 has the return ducts 42, 4
The pipes along the longitudinal direction of 3 are collectively arranged, and as shown in FIG. 3, each device 27b of the backup system 27, the pipes toward the pipe zone, and the wiring 35 can be mainly arranged. Therefore, the space of the equipment room 41 can be effectively used.

Although a gap is formed between the opening 25b of the slab 25 and the pipe and wiring in the above-mentioned embodiment, the present invention is not limited to the above-mentioned embodiment, and the above-mentioned gap is formed. It may be closed. In this case, since the gap 48 between the assemble floor 24 and the slab 25 and the inside of the equipment chamber 41 are completely separated, the effect of preventing the contact between the circulating air and the backup system 27 described above can be made more effective. it can. Further, by laying a stainless steel plate having a smooth surface roughness on the entire upper surface of the slab 25, the circulating air can pass between the assembly floor 48 and the return ducts 42, 43. It is possible to prevent the harmful gas and dust from being mixed, and further improve the air cleanliness.

[0031]

As described above, according to the present invention, the air that has passed through the room does not come into contact with the equipment installed in the space between the floor plate and the slab and the return duct having a highly clean inner surface is provided. Since it circulates through, it is possible to prevent gas and dust that are harmful to the air cleaning that have volatilized in the space below the slab from mixing into the air as in the conventional case, and the cleanliness of the air in the clean room is markedly improved compared to the conventional case. Can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing the configuration of an embodiment of a clean room according to the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a configuration diagram of an example of a conventional clean room.

[Explanation of Codes] 20 Clean Room 20a Floor Surface 20b Ceiling Surface 22 HEPA Filter 23 Indoor Room 24 Assemble Floor 25 Slab 25a, 25b Opening 26 Manufacturing Equipment 27 Backup System 27a Vacuum Pump 27b Equipment 28 Air Conditioner 28a Blower 29 With Adsorbent Filter 30, 31 Strut 40 Space 41 Equipment room 42, 43, 46, 47 Return duct 42a, 43a Side plate 42b, 43b Bottom plate 42c, 43c Upper plate 44, 45 Damper 46a, 46b Duct 47 Ceiling space 48 Gap

Claims (1)

[Claims] 1. A slab (25), which is a floor plate, is laid at a position having a predetermined height from the floor surface (20a), and a space between the floor surface (20a) and the slab (25). (4
0) equipment (2) necessary for the work performed in the room (23)
In a downflow type clean room in which 7) is installed, a return duct (42, 43) that collects air that has passed through the room (23) and returns the air to the inlet side of the blower (28a) in the space (40). ) Is provided and the inner surfaces of the return ducts (42, 43) are made highly clean.