JP3820609B2 - Method for forming filter duct in tunnel type clean room - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a filter duct forming method for a tunnel type clean room applied to a dust-free room or a sterilized room such as a semiconductor factory, a precision machine factory, and a chemical manufacturing factory.
[0002]
[Prior art]
For example, in semiconductor factories, the need for a super clean space has increased as a response to the sophistication of manufacturing technology associated with the high integration and ultra miniaturization of VLSI, and the cleanliness of class 1 to 100 There is a need for a tunnel type clean room having
[0003]
In order to meet this requirement, there are a vertical laminar flow type clean room and a tunnel type clean room.
However, in a vertical laminar flow type clean room, it is necessary to install a high-performance filter on the entire surface of the ceiling and to control the temperature and humidity as a whole room, which may cause imbalance in temperature control for each production device in the room. was there.
[0004]
On the other hand, a tunnel type clean room has an advantage that there is a possibility that it can be controlled with high accuracy for each working unit by dividing the area into areas.
An example of this tunnel type clean room is disclosed in Japanese Patent Application Laid-Open No. 61-282742.
This will be described with reference to FIG.
[0005]
In the figure, 1 is a tunnel type clean room. The tunnel type clean room 1 is partitioned by a drooping wall 2 into a high speed basin A, a boundary area C and a low speed basin B that require high cleanliness.
In the high speed basin A, a high performance filter 3 is provided. The high-performance filter 3 is attached to an air supply chamber 4 provided on the ceiling side in the tunnel-like room.
[0006]
Below the high-performance filter 3, a production machine 6 disposed on the floor 5 of the clean room 1 is located.
An air outlet 8 is provided between the hanging wall 2 on the low-speed basin B side and the ceiling 7. The air outlet 8 includes two high performance filters 9 and 10, an air supply chamber 11 for sending clean air to both the high performance filters 9 and 10, and a high performance filter located in the air supply chamber 11 from the hanging wall 2. 9 and a damper 12 provided at the upper part of 9.
[0007]
The boundary region C is formed by blowing from the high performance filter 9.
According to this tunnel type clean room 1, clean air is blown out in a laminar flow at a speed of about 0.3 to 0.4 m / sec in a substantially vertical downward direction through the high-performance filter 3 over the entire high-speed flow area A. In the low-speed basin B, clean air is blown out through the high-performance filter 10 so as to diffusely reach an indoor average descending wind speed of about 0.05 to 0.2 m / sec.
[0008]
In the boundary region C, the damper 12 is operated to blow clean air almost vertically downward at a speed of about 0.3 to 0.4 m / sec.
Since the same air flow as that of the high-speed basin A in the boundary region C is formed by the high-performance filter 9 and the damper 12, it is possible to prevent entrainment of dust generation from workers located on the boundary region C side. it can.
[0009]
FIG. 11 shows a tunnel type clean room described in Japanese Patent Laid-Open No. 61-282742.
In this case, the high-performance filter 13 is installed on the ceiling side, and a boundary outlet 14a and a low-speed basin 14b are provided in one outlet 14.
Also in this tunnel type clean room, it is possible to prevent entrainment of dust generation from workers located on the boundary region C side as in FIG.
[0010]
[Problems to be solved by the invention]
However, in the tunnel type clean room shown in FIG. 10, since the damper 12 adjusts the wind speed in the boundary region C, it takes time to adjust the damper 12, and the high-performance filters 9, 10 are each formed in a straight line. Since the angle formed by the high-performance filters 9 and 10 has a considerably large angle, a new boundary region is formed by the air flow blown from each of the high-performance filters 9 and 10. As a result, there is a high possibility that the boundary area C is merely displaced by the width of the high-performance filter 9.
[0011]
Moreover, in the tunnel type clean room shown in FIG. 11, since dynamic pressure is applied from the high-performance filter 13 into the outlet 14, the clean air is more likely to exit from the downward boundary region 14a than to the lateral low-speed region 14b. There is a possibility that it will be faster than the flow velocity of the high-speed basin A. In that case, it is not possible to prevent entrainment of dust generation from an operator located on the boundary area C side.
[0012]
The present invention has been made in order to solve such a conventional problem, and the object of the present invention is a tunnel type that can prevent dust generated from workers located in the boundary region from being caught in the high-speed basin. The object is to provide a method for forming a filter duct in a clean room.
[0013]
[Means for Solving the Problems]
The invention of claim 1 is provided with a punching panel which is perforated entirely or partially on the floor, and is divided into a high-speed basin and a low-speed basin that require high cleanliness by a hanging wall, and a fan filter unit is provided in the high-speed basin. the provided, the configured slow basin forms a cross section 1/4 elliptic arc shape on the whole surface is a filter, the filter duct forming method of tunnel clean room provided with the filter duct, of the cross section 1/4 elliptical arc The filter duct has a curvature of the outlet to the low-speed basin and a curvature of the outlet to the boundary between the high-speed basin where the worker is located and the low-speed basin according to the wind speed ratio of the high-speed basin and the low-speed basin. converting mechanism formed by changing the sectional shape from a longitudinal elliptical shape through an arc shape to the transverse elliptic arc shape, so as to flow with a downward uniform direction in the boundary region, the From the outlet to the boundary area, the boundary area blows off at a speed that gradually decreases from the high-speed basin to the speed of the low-speed basin, and from the outlet to the low-speed area, the low-speed area is 0.05 to 0.2 m / It forms so that it may blow off with the indoor average fall wind speed of sec.
[0014]
According to a second aspect of the present invention, in the tunnel type clean room filter duct forming method according to the first aspect , the fan filter unit provided in the high-speed flow area is positioned at a height substantially equal to a lower end height of the drooping wall. .
According to a third aspect of the present invention, in the tunnel type clean room filter duct forming method according to the first aspect , the fan filter unit provided in the high-speed basin is freely movable up and down.
According to a fourth aspect of the present invention, in the tunnel-type clean room filter duct forming method according to any one of the first to third aspects, the fan filter unit provided in the high-speed flow area has a lower end opening of a cylindrical unit body. A filter is disposed in the unit, and an axial flow type fan is disposed in the intake opening formed at the center of the upper surface of the unit body, and a square shape that is recessed below the fan. A sound insulating plate is arranged, and a plurality of rectifying plates are arranged on the inner periphery of the unit body so as to protrude inward and suppress swirling of the swirling flow generated by the rotation of the fan.
[0015]
According to a fifth aspect of the present invention, in the tunnel type clean room filter duct forming method according to any one of the first to fourth aspects, the blowout of the boundary portion between the high-speed flow area and the low-speed flow area below the hanging wall The speed is substantially equal to that of the high-speed basin.
The invention of claim 6 is the tunnel-type clean room filter duct forming method according to any one of claims 1 to 5 , wherein the filter duct having a substantially elliptical arc cross section provided in the low-speed flow area is The blowing speed of the area portion adjacent to the high speed area of the work area becomes lower as the distance from the high speed flow area increases.
[0016]
(Function)
According to the first to sixth aspects of the present invention, a high-speed laminar flow that flows toward the production machine is formed in the high-speed flow area as in the conventional case, and a medium-circular filter duct having a uniform direction is formed in the low-speed flow area and the boundary area. A slow flow can be formed.
[0017]
Therefore, no upward airflow occurs in the boundary area or the corner of the room, and a downward airflow with a stable room is obtained.
In the invention of claim 2, the pressure field in the vortex region due to the high-speed laminar flow with respect to the production machine rises, and the dust concentration decay time in the vortex can be shortened.
In the invention of claim 3, the fan filter unit provided in the high-speed flow area can be raised and lowered according to the application.
[0018]
In the invention of claim 4, a high-speed flow can be easily formed.
In the inventions according to claims 5 and 6, it is possible to prevent dust from being caught in the high-speed basin by the worker.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on embodiments shown in the drawings.
[0020]
FIG. 1 shows an embodiment of a filter duct forming method for a tunnel type clean room according to claims 1, 4 to 6.
In the figure, 21 is a tunnel type clean room. The tunnel type clean room 21 is partitioned by a drooping wall 22 into a high speed basin A, a boundary area C and a low speed basin B that require high cleanliness.
[0021]
The tunnel-type clean room 21 has a high-performance filter unit 24 that blows clean air into the tunnel-type clean room 21 on the ceiling 23 side. . The ceiling space 26 and the underfloor space 27 communicate with each other via an air conditioner 28. A production machine 29 is arranged on the floor.
[0022]
A fan filter unit 30 is disposed in the high-speed basin A. As shown in FIGS. 3 and 4, the fan filter unit 30 is provided with a high-performance filter 35 such as a ULPA filter or a HEPA filter in a lower end opening 33 of a cylindrical unit body 31 having a square cross section. Yes.
[0023]
An intake opening 39 is formed at the center of the upper surface 37 of the unit main body 31, and an axial flow fan 41 is disposed in the intake opening 39.
The axial flow type fan 41 has a bell mouth 43 fitted into the intake opening 39.
A boss portion 45 is arranged at the center of the bell mouth 43, and a blade 47 is fixed to the outer periphery of the boss portion 45.
[0024]
A motor 49 is connected to the boss portion 45, and the motor 49 is fixed to the bell mouth 43 via a bracket 51.
The boss portion 45 is provided with a tapered airflow guide cover 53 that projects in the suction direction.
A plurality of rectifying plates 55 are fixed to the upper part of the inner periphery of the unit main body 31 so as to protrude inward and suppress the swirling of the swirling flow generated by the rotation of the axial flow fan 41.
[0025]
A sound absorbing material 57 made of glass wool is attached to the current plate 55.
A sound insulating plate 59 is disposed below the axial flow type fan 41 of the unit main body 31.
The sound insulating plate 59 has a square shape, and the center thereof is located below the axial flow fan 41.
[0026]
A sound absorbing material 61 made of glass wool is attached to the sound insulating plate 59, and the sound insulating plate 59 is fixed to the inner surface of the unit main body 31 by a bracket 63.
A square-shaped recess 65 that is recessed downward is formed at the center of the sound insulating plate 59.
And the internal peripheral surface of the recessed part 65 is made into the inclined surface 67 which inclines toward the bottom face side.
[0027]
A rectangular annular outer sound insulation plate 69 is disposed below the sound insulation plate 59 of the unit main body 31.
The outer sound insulation plate 69 is arranged so that the inner peripheral portion thereof overlaps the sound insulation plate 59.
A sound absorbing material 71 made of glass wool is attached to the outer sound insulating plate 69.
[0028]
In FIG. 1, reference numeral 80 denotes a filter duct having an arcuate cross section. This filter duct 80 is made of a high-performance filter such as a ULPA filter or a HEPA filter, which has a substantially elliptical arc shape with a cross section of approximately 1/4 according to the wind speed ratio Va / Vb between the high-speed basin A and the low-speed basin B and the mounting pitch distance x of the filter duct -Cross section substantially 1/4 arc shape -Cross section substantially 1/4 horizontal elliptical shape.
[0029]
The larger the Va / Vb, the more air flow must be given to the boundary region C than the low-speed flow region B. The larger the filter duct mounting pitch distance x, the more air flow must be given to the low-speed flow region B.
Therefore , if the curvature of the outlet 81 is (1 / ρ) ₈₁ and the curvature of the outlet 82 is (1 / ρ) ₈₂ , the following function is obtained.
Va / Vb × α 1 / x ∝ β × (1 / ρ) ₈₁ / (1 / ρ) ₈₂
Here, α and β are coefficients.
As is clear from this function, it is necessary to increase the value of (1 / ρ) ₈₁ / (1 / ρ) ₈₂ as Va / Vb increases. Can be given. When the filter duct mounting pitch distance x is large , the flow rate to the low-speed basin B can be increased by adjusting the value of (1 / ρ) ₈₁ / (1 / ρ) ₈₂ to be small. .
[0030]
The filter duct 80 includes a blower outlet 81 toward the low-speed flow region B and a blower port 82 toward the boundary region C. A punching resistor can be attached to the air outlet 81, or the folding density and folding height of the high-performance filter can be changed. By increasing the curvature of the filter of the air outlet 81 from the air outlet 82, the filter medium area of the air outlet 82 can be increased from that of the air outlet 81. By increasing the filter medium area in this way, the filter duct 80 is assumed to have increased the air volume from the outlet 82 to the boundary area C rather than the outlet 81 to the low-speed flow area B side.
[0031]
Next, the operation of the present embodiment will be described.
By driving the air conditioner 28 and supplying clean air to the fan filter unit 30, the high performance filter unit 24 and the filter duct 80, clean air is supplied to the tunnel type clean room 21.
At that time, in the fan filter unit 30, after the air sucked from the intake opening 39 by the axial flow fan 41 is turned into a swirling flow, the swirling flow collides with the rectifying plate 55 at the outer peripheral portion. It is suppressed and flows downward, passes between the sound insulation plate 59 and the outer sound insulation plate 69, reaches the high performance filter 35, is purified by the high performance filter 35, and then enters 0.3 in the high speed flow area A. It is blown out at a high speed of about 0.4 m / sec.
[0032]
On the other hand, clean air is blown out from the high-performance filter unit 24 at such a low speed that the indoor average descending wind speed is about 0.05 to 0.2 m / sec.
And in the filter duct 80, since the blower outlet is formed with the whole surface filter, it is not influenced by dynamic pressure, but from the blower outlet 82 to the boundary zone C from the blower outlet 82 by the difference in the pressure loss of each part filter. Clean air at a speed gradually reduced to the speed of the low-speed basin B, and the indoor average descending wind speed of about 0.05 to 0.2 m / sec from the outlet 81 to the low-speed basin B side. Clean air can be blown out at low speed.
[0033]
Therefore, a downward stable airflow is formed between the high-speed flow area A and the boundary area C, and no upward airflow is generated.
That is, the dust generation from the worker in the boundary area C is not involved in the high-speed flow area A.
However, unlike the conventional case, since the complicated operation of operating the damper is not required, the management of the tunnel type clean room is easy.
[0034]
In addition, since it is only necessary to install the filter duct 80 in the boundary region C, the structure is simple.
In the fan filter unit 30 described above, the use of the axial flow fan 41 generates a swirling flow toward the outside of the axial flow fan 41. This swirling flow is generated in the outer peripheral portion of the unit main body 31. Since it collides with a plurality of rectifying plates 55 arranged at the upper part of the inner periphery and is suppressed and flows downward, it is blown into the room through the high-performance filter 35. It can be made uniform.
[0035]
In addition, since it is not necessary to change the direction of the air flow with a rectifying perforated plate or the like, it is possible to prevent the discharge resistance from increasing.
Furthermore, noise generated from the axial flow fan 41 can be reliably insulated by the sound insulation plate 59 disposed between the axial flow fan 41 and the high-performance filter 35.
In the fan filter unit 30 described above, the unit main body 31 has a square cross section, and the centers of the axial fan 41 and the square sound insulation plate 59 are arranged at the center thereof. Air is discharged under the conditions, and the discharge wind speed distribution from the high-performance filter 35 can be made more uniform.
[0036]
Further, since the square recess 65 that is recessed downward is formed in the central portion of the sound insulating plate 59 and the inner peripheral surface of the recess 65 is inclined toward the bottom surface side, the air that collides with the bottom surface of the recess 65 is The airflow is not disturbed smoothly by being guided by the inclined surface 67 toward the outside, and the discharge air velocity distribution from the high performance filter 35 can be made more uniform.
Further, in the fan filter unit 30 described above, since the inner periphery of the outer sound insulation plate 69 overlaps below the sound insulation plate 59 of the unit main body 31, the noise generated from the axial flow fan 41 is directly filtered. 35 is prevented, and the silencing effect can be improved.
[0037]
Further, since the airflow guide cover 53 is disposed on the boss portion 45 of the axial flow fan 41, the air flow becomes smooth, the noise of the axial flow fan 41 is reduced, and the efficiency of the axial flow fan 41 is improved. Can be improved.
The fan filter unit is not limited to the illustrated one, and any fan filter unit may be used as long as the fan and the high-performance filter are combined.
[0038]
FIG. 5 shows a modification of the filter duct forming method for the tunnel type clean room shown in FIG.
In the present embodiment, the high performance filter unit 24 and the filter duct 80 are also provided with fans 83 and 84.
[0039]
This embodiment can achieve the same effects as those of the above embodiment.
FIG. 6 shows an embodiment of a filter duct forming method for a tunnel type clean room according to claim 2.
The fan filter unit 30 is lowered to the vicinity of the boundary area C of the filter duct 80.
When the distance L ₁ between the fan filter unit 30 and the production machine 29 is made close to 1050 mm as shown in FIG. 7, and when the distance L ₂ between the fan filter unit 30 and the production machine 29 is made 2550 mm away as shown in FIG. The vortex region at the top of the production apparatus 29 and the dust discharge capability were tested.
[0040]
The dust attenuation time until the dust particle size was 0.05 μm and 100,000 / min became 30,000 / min (the time during which the dust concentration decreased to 30%) was measured.
In the case of FIG. 7, it was 6.31 seconds, and in the case of FIG. 8, it was 9.96 seconds.
As described above, it has been found that the purification capacity is greater when the fan filter unit 30 is closer to the production machine 29.
[0041]
This is because by providing the fan filter unit 30 in the vicinity of the production apparatus 29, pressure loss from the ceiling surface is reduced and the pressure field in the vortex region X is increased.
From the results of the three-dimensional numerical analysis (simulation), the region having a large dust concentration is reduced. This is also because the pressure field in the vortex region X rises.
In the present embodiment, there is an effect that the dust attenuation time can be shortened in addition to the operational effects of the above embodiment.
[0042]
FIG. 9 shows a modification of the tunnel-type clean room filter duct forming method shown in FIG.
In this embodiment, the high performance filter unit 24 and the filter duct 80 are also provided with fans 85 and 86.
This embodiment can achieve the same effects as those of the above embodiment.
In the above embodiments, the main part of the tunnel type clean room has been described. However, the overall configuration is, for example, a clean tunnel as shown in FIG. 1 of Japanese Patent Laid-Open No. 61-282742. It has a similar form.
[0043]
The fan filter unit 30 may be fixed at a predetermined position as in each of the above embodiments, or may be fixed at a predetermined position according to the purpose through any lifting device. (Claim 3).
[0044]
【The invention's effect】
As described above, in the tunnel type clean room filter duct forming method according to the first to sixth aspects, the damper is provided in the boundary region as in the conventional tunnel type clean room to adjust the flow velocity with the low speed basin. No operation is required.
[0045]
In addition, since a switching device using a damper is not required, the device is simplified.
Further, since the fan filter unit is provided at a position close to the production apparatus, the dust attenuation time is shortened, that is, the area of high dust concentration in the vortex area generated in the production apparatus is reduced, and the purification capability is increased. .
[Brief description of the drawings]
FIG. 1 is an explanatory view showing an embodiment of a method for forming a filter duct of a tunnel type clean room according to claims 1, 4 to 6. FIG.
FIG. 2 is an explanatory diagram showing a flow of clean air in the tunnel type clean room of FIG. 1;
3 is a cross-sectional view showing a fan filter unit used in the tunnel type clean room of FIG. 1. FIG.
4 is a cross-sectional view of FIG. 3. FIG.
FIG. 5 is an explanatory view showing another embodiment of a filter duct forming method for a tunnel type clean room according to claims 1, 4 to 6.
6 is an explanatory view showing an embodiment of a filter duct forming method for a tunnel type clean room according to claim 2. FIG.
7 is an operation explanatory diagram of the tunnel type clean room of FIG. 6; FIG.
8 is an operation explanatory diagram of the tunnel type clean room of FIG. 6;
FIG. 9 is an explanatory view showing another embodiment of a filter duct forming method for a tunnel type clean room according to claim 2;
FIG. 10 is an explanatory view showing a conventional tunnel type clean room.
FIG. 11 is an explanatory view showing a conventional tunnel type clean room.
[Explanation of symbols]
21 Tunnel-type clean room 22 Hanging wall 23 Ceiling 24 High-performance filter unit 25 Floor 26 Ceiling space 27 Under-floor space 28 Air conditioner 29 Production machine 30 Fan filter unit 31 Unit main body 35 High-performance filter 41 Axial flow fan 80 Filter duct 81, 82 Outlet A High-speed flow area B Low-speed flow area C Boundary area

Claims (6)

A punching panel that is fully or partially perforated on the floor is provided, and is divided into a high-speed basin and a low-speed basin that require high cleanliness by a hanging wall, and a fan filter unit is provided in the high-speed basin, In the method for forming a filter duct of a tunnel type clean room provided with a filter duct , the entire surface having a substantially elliptical arc shape in section is constituted by a filter.
Filter duct of the cross section 1/4 elliptical arc shape, the outlet curvature of the boundary zone between the high-speed basin and the slow basin outlet curvature and workers to the slow basin is positioned, the high-speed While changing the cross-sectional shape from the vertical elliptical arc shape to the horizontal elliptical arc shape through the arc shape according to the wind speed ratio of the basin and the low-speed basin ,
The boundary area blows out from the outlet to the boundary area at a speed that gradually decreases from the high-speed flow area to the speed of the low-speed flow area so that the flow has a uniform downward direction in the boundary area. A tunnel-type clean room filter duct forming method , characterized in that the low-speed region is blown out at an indoor average descending wind speed of 0.05 to 0.2 m / sec. The method for forming a filter duct for a tunnel type clean room according to claim 1, wherein the fan filter unit provided in the high-speed flow area is positioned at a height substantially equal to a lower end height of the hanging wall. 2. The method for forming a filter duct in a tunnel type clean room according to claim 1, wherein the fan filter unit provided in the high-speed basin is movable up and down. The fan filter unit provided in the high-speed flow area has a filter disposed at the lower end opening of the cylindrical unit body and an axial flow fan disposed at the intake opening formed at the center of the upper surface of the unit body. A square sound insulation plate recessed below the fan and projecting inward at the upper part of the inner periphery of the unit body to generate a swirling flow generated by the rotation of the fan. The method for forming a filter duct of a tunnel type clean room according to any one of claims 1 to 3, wherein a plurality of baffle plates for suppressing turning are arranged. 5. The blowout speed at the boundary between the high-speed flow area and the low-speed flow area below the hanging wall is substantially equal to the high-speed flow area. 6. Method for forming a filter duct in a tunnel type clean room. The filter duct having an approximately ¼ elliptical arc cross section provided in the low-speed basin is characterized in that the blowing speed of the area portion adjacent to the high-speed area of the work area becomes low as the distance from the high-speed basin increases. The method for forming a filter duct in a tunnel type clean room according to any one of claims 1 to 5.

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