JP2580893B2 - Clean room fan filter unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fan filter unit for a clean room, and more particularly to a fan filter unit for a clean room installed in a semiconductor manufacturing factory or the like.

[0002]

2. Description of the Related Art Conventionally, since a manufacturing environment for semiconductor products such as ICs and LSIs requires a dust-free environment, the manufacturing is performed in a clean room. FIG. 4 is a schematic structural view of a conventional clean room. As shown in FIG. 4, the clean room 10 includes an outer room 12 and an inner room 14. A circulation chamber 16 is formed between the outer chamber 12 and the inner chamber 14, and fan filter units 18 are arranged on a ceiling surface of the inner chamber 14.

As shown in FIG. 5, the fan filter unit 18 has an air supply fan 22 provided inside a casing 20 and a high-performance (H)
An EPA) filter 24 is mounted. The air conditioner 30 shown in FIG.
Are connected. Therefore, the conditioned air from the air conditioner 30 passes through the duct 28, is sucked into the air supply fan 22 from the supply port 26, and is dust-removed by passing through the HEPA filter 24. Flowed. The downflowed clean air passes through the grating floor surface 32 and is sucked into the underfloor chamber 34, and a part of the sucked air is sent from the exhaust port 36 to the air conditioner 30 via the duct 38. And
After being air-conditioned again, the air is blown out of the fan filter unit 18 through the above-described system path. On the other hand, the remaining air passes through the circulation chamber 16, is taken in from the air inlet 40 shown in FIG. 5, is mixed with the air-conditioned air in the casing 20, and is blown out from the fan filter unit 18.

Incidentally, the fan filter unit 1
Since the temperature of the clean air blown out from the heater 8 rises due to heat generated by the semiconductor manufacturing apparatuses 42 and 44 installed in the inner chamber 14, a part of the clean air is cooled by the air conditioner 30. This results in lower pressure loss than returning the entire amount of the clean air to the air conditioner 30, and this effect can significantly reduce the size of the air conditioner 30. Further, dampers 4 attached to the supply port 26 and the intake port 40, respectively.
By adjusting the opening degrees of 6, 48, it is possible to blow out clean air whose temperature has been adjusted according to the amount of heat generated below each fan filter unit 18.

[0005] However, in such a fan filter unit 18, dust in the air-conditioned air is removed from the HEPA filter 24.
, But cannot remove acidic gases such as NO _x , SO _x , and HF. Therefore, as a means for solving such a problem, a chemical filter 50 filled with activated carbon or a chemical adsorbent for removing acidic gas is installed at the outside air inlet of the air conditioner 30 to remove acidic gas from outside air. ing. Also, the inner room 16 of the clean room 10
Acid gas such as acid and organic chemicals evaporated in the above is exhausted from the draft.

[0006]

However, the acids and organic chemicals evaporated in the inner chamber 16 of the clean room 10 are
Since the draft can be completely sealed,
6 has the disadvantage that it is adversely affected by diffusion to the semiconductor. For example, when HF used for etching a wafer diffuses into the inner chamber 16, H of the fan filter unit 18 becomes high.
The glass component of the EPA filter 24 is corroded to generate B and Na. When these components adhere to the wafer, there is a defect that the semiconductor causes an abnormality and the yield is deteriorated. Further, there is a disadvantage that another acid gas also invades the metal in the clean room 10 and deteriorates the yield as described above.

As a means for solving such a problem,
There is a method in which a chemical filter is mounted on the upstream or downstream side of the air supply fan 22 of the fan filter unit 18 to remove an acidic gas by this chemical filter. In this method, the amount of air blown from the air supply fan 22 is reduced. Therefore, there is a disadvantage that an air supply fan having a large capacity must be used, and the power is increased.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a fan filter unit for a clean room capable of removing an acidic gas with low pressure loss.

[0009]

According to the present invention, there is provided a fan filter unit which is provided on a ceiling surface of a clean room and blows clean air into the clean room. An internally provided casing, a supply port for conditioned air formed in the casing and opened on the upstream side of the fan, and an intake port for circulating air in a clean room formed on the casing and opened on the upstream side of the fan. In a fan filter unit for a clean room, a chemical filter configured to remove acidic gas formed in a honeycomb shape is attached to the intake port.

[0010]

According to the present invention, a honeycomb-shaped chemical filter capable of removing an acidic gas is attached to the intake port of the circulating air of the fan filter unit. Thus, since the chemical filter is formed in a honeycomb shape, it is possible to prevent an increase in pressure loss at the intake port and to remove an acid gas in the circulating air.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a clean room fan filter unit according to the present invention. FIG. 1 shows an embodiment of a clean room to which a fan filter unit of a clean room according to the present invention is applied, and the same or similar members as those in the conventional example shown in FIGS. 4 and 5 are denoted by the same reference numerals. I will explain.

As shown in FIG. 1, a clean room 10 includes an outer room 12 and an inner room 14 maintained in a dust-free environment. A circulation chamber 1 is provided between the outer chamber 12 and the inner chamber 14.
6 are formed, and a plurality of fan filter units 18 are arranged on the ceiling surface 15 of the inner chamber 14. As shown in FIG. 2, the fan filter unit 18 has an air supply fan 22 provided inside a casing 20.
On the downstream side of the air supply fan 22, the ceiling surface 1 of the inner chamber 14 is provided.
A high-performance (HEPA) filter 24 is mounted so as to be flush with the opening 15a of the fifth embodiment. A supply port 26 is formed on the upstream side of the air supply fan 22 of the casing 20.
The air conditioner 30 shown in FIG. Further, an air volume adjusting damper 29 is mounted in a duct 27 forming the supply port 26.

Therefore, the conditioned air from the air conditioner 30 is
The air passes through the duct 28 and is taken into the air supply fan 22 from the supply port 26. The air-conditioned air that has been taken in is HEP
The dust is removed by passing through the A-filter 24, and the dust is down-flowed toward the inner chamber 14 shown in FIG. The downflowed clean air passes through the grating floor 32 and is sucked into the underfloor chamber 34, and a part of the sucked air is sent from the exhaust port 36 to the air conditioner 30 through the duct 38. After being air-conditioned again, the air is blown out of the fan filter unit 18 through the above-described system path.

On the other hand, the remaining air not taken into the exhaust port 36 passes through the circulation chamber 16 and is taken in from the intake port 40 shown in FIG. 2 of the fan filter unit 18 and mixed with the conditioned air in the casing 20. After that, the air is blown out from the fan filter unit 18. The intake port 4
A chemical filter 52 for removing acidic gases such as NO _X , SO _X , and HF is mounted in the duct 41 that forms zero.

As shown in FIG. 3, the chemical filter 52 is formed in a honeycomb shape having a large number of through holes 54 formed on the surface thereof in order to prevent an increase in pressure loss. Next, the operation of the clean room fan filter unit configured as described above will be described. A semiconductor manufacturing apparatus 42 installed in the inner room 16 of the clean room 10,
When the acid or the organic chemicals diffuse from the base 44, the air containing the acid or the organic chemicals, that is, the acid gas, together with the air-conditioning air blown out from the fan filter unit 18, is supplied to the underfloor chamber 3.
2. After passing through the circulation chamber 16 and being sucked from the intake port 40 of the fan filter unit 18, the chemical filter 5
Pass 2 At this time, the acidic gas is removed by the activated carbon in the chemical filter 52 when passing through the many through holes 54 of the chemical filter 52. Accordingly, since the acids and organic chemicals are removed from the air sucked into the casing 20 of the fan filter unit 18, the glass component of the HEPA filter 24 of the fan filter unit 18 is not corroded. Thereby, it is possible to prevent the semiconductor products in the inner chamber 16 from being adversely affected.

Further, since the chemical filter 52 is formed in a honeycomb shape in consideration of preventing the pressure loss from increasing as described above, the acidic gas can be removed with a low pressure loss. Further, the acidic gas contained in the outside air can be removed with a low pressure loss by installing a honeycomb-shaped chemical filter 31 in the air conditioner 30.

The temperature of the conditioned air from the fan filter unit 18 can be adjusted by operating an air volume adjusting damper 29 attached to the conditioned air supply port 26 of the fan filter unit 18. In other words, if the supply port 26 is throttled by the air flow adjusting damper 29, the conditioned air amount decreases by the pressure loss of the air flow adjusting damper 29, and the circulating air amount passing through the chemical filter 52 increases by the reduced air amount. . Thereby, the temperature of the conditioned air from the fan filter unit 18 can be increased.

[0018]

As described above, according to the fan filter unit for a clean room according to the present invention, a honeycomb-shaped chemical filter capable of removing acidic gas is attached to the intake port of the circulating air of the fan filter unit. Acid gas in the circulating air can be removed by preventing an increase in pressure loss at the mouth.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of a clean room to which a fan filter unit for a clean room according to the present invention is applied.

FIG. 2 is an explanatory view of a fan filter unit of a clean room according to the present invention.

FIG. 3 is a perspective view of a chemical filter attached to a fan filter unit of a clean room according to the present invention.

FIG. 4 is an explanatory view showing an embodiment of a clean room to which a fan filter unit of a conventional clean room is applied.

FIG. 5 is an explanatory view of a conventional fan filter unit of a clean room.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Clean room 18 ... Fan filter unit 26 ... Air supply port 29 ... Air volume control damper 40 ... Intake port 52 ... Chemical filter 54 ... Through hole.

Claims (1)

(57) [Claims] 1. A fan filter unit disposed on a ceiling surface of a clean room and blowing clean air into the clean room, comprising: a casing in which a fan and a high-performance filter are installed; and an upstream side of the fan formed in the casing. In a fan filter unit for a clean room, comprising a supply port for air-conditioned air opened in the casing, and an intake port for circulating air in a clean room formed in the casing and opened on the upstream side of the fan, the intake port has a honeycomb. A fan filter unit for a clean room, wherein a chemical filter configured to remove an acidic gas is provided.