JP3208753B2 - Air conditioner for clean room - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a clean room air conditioner, and more particularly to a clean room air conditioner for aging a high performance air filter used as a final filter.

[0002]

2. Description of the Related Art In recent years, in semiconductor manufacturing factories, the production process has become extremely complicated with the increase in the degree of integration of semiconductors, and the cleanliness in a clean room, which is a production site, has become severe. FIG. 4 is a configuration diagram of an existing air conditioning system for a clean room. Air conditioning for clean room 1
Air supply, return air, and exhaust are broadly divided into three categories. The air volume is controlled to maintain a positive pressure at all times to maintain high cleanliness inside.

The air-conditioning air supplied to the clean room 1 is obtained by adjusting the temperature and humidity of the introduced outside air and removing dust by an air conditioner 2, and further comprises a fan filter unit 3 comprising a fan, a HEPA pretreatment filter and a dust removal HEPA filter. To remove particles having a size of 0.01 μm or more and supply them into the clean room. The supply of air-conditioning air to the clean room 1 is performed from the ceiling, and the supplied air-conditioning air is dust generated from the worker 4 in the clean room 1, the semiconductor manufacturing apparatus 5 and the semiconductor cleaning apparatus 6 installed in the clean room 1, and the like. And beneath the floor with heat. The air-conditioning air guided under the floor passes through an air passage formed in the wall, is cooled by the dry coil unit 7 installed in the air passage, and is returned to the ceiling. The air-conditioned air returned to the ceiling is mixed with the air-conditioned air supplied by the air conditioner 2, purified again by the fan filter unit 3, and supplied into the clean room 1.

In the semiconductor cleaning apparatus 6, an acid-
Because chemicals such as luka and organic solvents are used, these
A semiconductor cleaning device to prevent leakage into the lean room 1
The air-conditioning air in the vicinity of 6 is forcibly sucked by the exhaust duct 8 and
Exhaust outside Lean Room 1. FIG.
It is a block diagram. As shown in FIG.
The outside air introduced from the suction port 12 is removed by coarse dust.
Removal filter 14 → Chemical filter 16 → Cooling coil 1
8 → Reheat coil 20 → Humidifier 22 → HEPA pretreatment filter
Filter 24 → pass through HEPA filter 26 and clean
Guided to the room. At this time, the outside air introduced is
SO2 contained by passing through the filter 16 _XAnd NO_X
Harmful gas is removed,
As a result, the dew point is cooled and dehumidified to about 10 ° C. Soshi
And by passing through the reheat coil 20,
Is heated to a desired temperature by passing through the humidifier 22.
Steam humidified to humidity. In addition, HEPA pre-treatment
By passing through the filter 24 and the HEPA filter 26,
Particles of 0.01 μm or more are removed.

[0005]

The dust filters such as the HEPA pre-treatment filter and the HEPA filter provided in the fan filter unit and the air conditioner are made of glass fiber. Is generated, and the air-conditioning air supplied to the clean room is contaminated with boron.

FIG. 6 is a graph showing the relationship between the ventilation time of the HEPA filter and the amount of boron generated. As shown in the figure, the amount of generated boron tends to be large at the beginning of ventilation. For this reason, in the clean room, a break-in operation is performed about one month before the normal operation, and the amount of boron generated from the HEPA pretreatment filter and the HEPA filter is reduced.

However, the HEP installed in the air conditioner
Since the A pre-processing filter and the HEPA filter need to be replaced at the time of periodic inspection, the replaced HEPA pre-processing filter and HEPA filter are used for aging.
Used in the absence of For this reason, high-concentration boron was sent into the clean room in the initial stage of operation, and the sent boron adhered to the wafer surface, resulting in a problem of poor wafer production.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a clean room air conditioner that can reduce the generation of contaminants from a filter.

[0009]

In order to achieve the above object, the present invention provides a clean room air conditioner for supplying air conditioning air to a clean room through a dust removing filter. An aging part for installing a filter for dust removal is provided, and a part of the air-conditioning air is passed through the new filter for replacement dust removal installed in the aging part to guide the filter to a space other than the clean room. The present invention is characterized in that the dust removing filter is aged to remove pollutants generated from the dust removing filter.

According to the present invention, an aging portion for installing a new filter for replacement is provided in the air conditioner main body casing, and a part of the conditioned air is supplied to the aging portion. Then, the conditioned air supplied to the aging section passes through a new filter for replacement and is guided to a space other than the clean room. Accordingly, a contaminant generated from the filter in the initial stage of operation is not sent into the clean room, so that a clean room with extremely high cleanliness can be provided. In addition, the aging of a new filter for replacement can be performed during the normal operation of the air conditioner, which is efficient.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a clean room air conditioner according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a configuration diagram of a first embodiment of a clean room air conditioner according to the present invention. As shown in the figure, the casing 30 of the air conditioner 28 has an air conditioning room 3 inside.
1 and an aging chamber 54 are formed. Air conditioning room 31
At the left end in the drawing, a suction port 32 for outside air is formed, while at the right end in the drawing, an air outlet 34 for conditioned air generated in the air conditioning room 31 is formed. The air outlet 34 is connected to a duct 36 communicating with the clean room, and the conditioned air generated in the air conditioning room 31 is supplied into the clean room via the duct 36.

Fans 38, 38 are installed at substantially the center of the air-conditioning chamber 31. When the fans 38, 38 are driven, outside air flows from the air inlet 32 through the air-conditioning chamber 31.
Introduced within. In the upstream portion of the fans 38, 38,
A coarse dust removal filter 40, a chemical filter 42, a cooling coil 44, a reheating coil 46, and a humidifier 47 are provided at predetermined intervals in this order from the suction port 34 side.

On the other hand, downstream of the fans 38, 38, HEPA pre-processing filters 48, 48.
Are installed. The air-conditioning chamber 31 is formed with an intake 52 at the upper right end in the drawing, and communicates with the aging chamber 54. The aging chamber 54 is formed along the air-conditioning chamber 31 and has an outlet 5 at the left end in the figure.
8 are formed. The outlet 58 communicates with a space other than the clean room, for example, a space such as an office room, through the duct 56. The intake 52 and the outlet 58
Are provided with dampers 60, 62, respectively. By opening and closing the dampers 60, 62, supply of conditioned air to the aging chamber 54 and aging chamber 54
The supply of air-conditioned air to the space other than the clean room is adjusted. In the aging chamber 54, a new replacement HEPA pretreatment filter 48 ', 48'...
A filters 50 ′, 50 ′,.
2 is introduced into the aging chamber 54 by the HEPA pretreatment filters 48 ′, 48 ′,.
Are passed through the A filters 50 ′, 50 ′,... And guided to a space other than the clean room. . And the HEPA filter 50 '.
', 50' ... are aged.

The operation of the first embodiment of the air conditioner for a clean room according to the present invention configured as described above is as follows. First, in the air-conditioning room 31, H
The EPA pre-processing filters 48, 48... And the HEPA filters 50, 50. On the other hand, in the aging chamber 54, a new HEPA pretreatment filter 48 'for replacement,
48 ′ and HEPA filters 50 ′, 50 ′.

Next, the fans 38, 38 are driven in this state. The air-conditioning room 3 is drawn from the suction port 32 by the fans 38 and 38.
The outside air introduced into 1 is a dust removal filter 40 → a chemical filter 42 → a cooling coil 44 → a reheating coil 46 →
After passing through the humidifier 47 → the HEPA pretreatment filter 48 → the HEPA filter 50, it is guided into the clean room.
At this time, the outside air passes through the chemical filter 42 to remove harmful gases such as SO _X and NO _X contained therein, and passes through the cooling coil 44 to have a dew point of 10 ° C.
Cooled and dehumidified until around. Then, by passing through the reheating coil 46, the humidifier 4 is heated to an arbitrary temperature.
7 to steam humidify to an arbitrary humidity. Further, by passing through the HEPA pre-processing filter 48 and the HEPA filter 50, particles of 0.01 μm or more are removed.

On the other hand, a part of the conditioned air that has passed through the HEPA filter 50 is guided from the intake 52 into the aging chamber 54. The conditioned air guided into the aging chamber 54 is:
Replacement new HEPA pretreatment filter 48 'and HE
After passing through the PA filter 50 ′, it is guided to a space other than the clean room via the duct 58. Normally, ventilation for about one month allows a new HEPA pretreatment filter 48 '.
And the amount of boron generated from the HEPA filter 50 'is reduced. In this state, the air conditioner 28 is operated for about one month, and the amount of boron generated from the replacement new HEPA pretreatment filter 48' and the HEPA filter 50 'is changed. When the pressure drops, the dampers 60 and 62 are closed.

Replacement New HEPA Pretreatment Filter 4
8 'and HEPA filter 50' are stored in this state,
At the time of the filter replacement performed at the time of the periodic inspection of the air conditioner 28, the HEPA pretreatment filter 48 and the HEPA filter 5 which have been used so far and are installed in the air conditioning room 31 have been used.
Replace with 0. At this time, the HEPA pre-processing filter 48 and the HE
The PA filter 50 is discarded. And aging room 5
4 again contains a new HEPA pretreatment filter 4 for replacement.
8 ′ and the HEPA filter 50 ′ are installed.

As described above, according to the air conditioner for clean room of the first embodiment, the HEPA pretreatment filter 48 and the HEPA
When replacing the EPA filter 50, the HEPA pre-processing filter 48 'and the HEPA filter 5
Since 0 'can be used, high-concentration boron generated in the early stage of operation unlike the conventional case is not sent into the clean room. Therefore, the production failure of the wafer due to the generated boron does not occur. In addition, the aging of a new filter for replacement can be performed during the normal operation of the air conditioner 28, which is efficient.

In the first embodiment, the aging chamber 54
Is formed in the casing 30, but may be formed in the middle of a duct for guiding the conditioned air to a space other than the clean room. FIG. 2 is a configuration diagram of a second embodiment of a clean room air conditioner according to the present invention. The clean room air conditioner 28 according to the first embodiment includes a HEPA filter 4.
8 is introduced into the aging room 54, but the clean room air conditioner 6 of the second embodiment is used.
At 1, air conditioning air before passing through the HEPA pretreatment filter 48 is introduced into the aging chamber 54 as described below. Note that the same members and the same devices as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The air-conditioning room 31 is constructed in the same manner as in the first embodiment. The HEPA pre-processing filter 4 of this air conditioning room 31
An intake 52 is formed in the upper part on the upstream side of 8, and communicates with the aging chamber 54. The aging chamber 54 is formed along the air-conditioning chamber 31, and has an outlet 58 at the right end in the figure. The outlet 58 communicates with a space other than the clean room, for example, a space such as an office room, through the duct 56. Further, a return air port 64 is formed at the lower right end of the aging chamber 54 in the figure,
It is connected to the downstream of the PA filter 50. Further, dampers 60, 62, and 66 are provided at the intake 52, the outlet 58, and the return air port 64, respectively, and by opening and closing the dampers 60, 62, and 66, the air conditioning room 31 is opened. The supply of the air-conditioned air to the aging room 54, the supply of the air-conditioned air from the aging room 54 to the clean room, and the supply of the air-conditioned air from the aging room 54 to the air-conditioned room 31 are adjusted. In the aging chamber 54, the first
Replacement new HEPA pre-processing filters 48 ', 48' ... and HEPA filters 50 ', 50' as in the embodiment.
Are installed, and dust removal filters 68, 68 are further installed on the upstream side. And the intake 5
The air-conditioning air introduced into the aging chamber 54 from the second through the dust removing filters 68, 68
.. And the HEPA filters 50 ′, 50 ′,... And guided to a space other than the clean room.

The operation of the second embodiment of the air conditioner for a clean room according to the present invention configured as described above is as follows. First, similarly to the first embodiment, the inside of the air-conditioning room 31 includes:
HEPA pretreatment filters 48 and 4 that have been aerated for about one month
8 and the HEPA filters 50, 50,. On the other hand, there is a new HEPA for replacement in the aging chamber 54.
The pre-processing filters 48 ', 48', and the HEPA filters 50 ', 50', are installed.

Next, the fans 38, 38 are driven in this state. At this time, the dampers 6 of the inlet 52 and the outlet 58
0 and 62 are opened, and the damper 66 of the return air port 64 is closed. The outside air introduced into the air-conditioning chamber 31 from the suction port 32 by the fans 38, 38 is removed by a coarse dust removal filter 40 →
Chemical filter 42 → Cooling coil 44 → Reheat coil 4
6 → Humidifier 47 → HEPA pretreatment filter 48 → HEP
After passing through the A filter 50, it is guided into the clean room.

On the other hand, a part of the conditioned air that has passed through the humidifier 47 is guided from the intake 52 into the aging chamber 54.
The air-conditioned air guided into the aging chamber 54 passes through the dust removal filter 68, and then is replaced with a new HEPA.
After passing through the pre-processing filter 48 ′ and the HEPA filter 50 ′, it is guided to a space other than the clean room via the duct 58.

In this state, the air conditioner 61 is operated for about one month, and when the amount of boron generated from the replacement new HEPA pretreatment filter 48 'and HEPA filter 50' decreases, the dampers 60 and 62 are closed. As in the first embodiment, the replacement new HEPA pretreatment filter 48 'and the HEPA filter 50' are stored in this state, and the air conditioning room is replaced when the air conditioner 61 is periodically replaced. The HEPA pre-processing filter 48 and the HEPA filter 50 which have been used up to now are installed in the inside 31.

In the air conditioner 61 for a clean room according to the second embodiment, the air conditioner 61 is operated for about one month, and a new HEPA pretreatment filter 48 'for replacement and a HEP are replaced.
When the amount of boron generated from the A filter 50 'is reduced, the damper 62 of the air outlet 58 is closed, and the damper 66 of the return air port 64 is opened, so that the air-conditioning air introduced into the aging chamber 54 is returned to the air-conditioning chamber 31. It can be introduced inside and lead to a clean room.

As described above, according to the clean room air conditioner 61 of the second embodiment, like the clean room air conditioner 28 of the first embodiment, the HEPA pre-processing filter 48 and the HEPA filter 50 are used. At the time of exchange,
Since the pre-aged HEPA pre-processing filter 48 'and HEPA filter 50' can be used,
Unlike the conventional case, high-concentration boron generated in the initial stage of operation is not sent into the clean room.

In the first and second embodiments, the air-conditioned air that has passed through the aging chamber 54 is led to a space other than a clean room such as an office.
It may be introduced into a clean room such as a clean room in a post-process where there is no problem of boron contamination, or into the outside air. FIG. 3 is a configuration diagram of a third embodiment of a clean room air conditioner according to the present invention.

The clean room air conditioner 28 of the first embodiment has a new H for replacement in the aging chamber 54.
Although the air-conditioned air that has passed through the EPA filter 50 is guided to a space other than the clean room, the clean-room air conditioner 70 according to the third embodiment passes through a new replacement HEPA pre-treatment filter 48 as described below. The air-conditioned air thus returned is returned to the air-conditioned room 31 and circulated. Note that the same members and the same devices as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The air-conditioning room 31 is constructed in the same manner as in the first embodiment. At the upper right end of the air conditioning room 31 in the figure,
An intake 52 is formed and communicates 2 with the aging chamber 54. The aging chamber 54 is formed along the air-conditioning chamber 31, and has a return air port 72 at the right end in the figure, and communicates with the fans 38 and 38 upstream of the air-conditioning chamber 31. Further, dampers 60 and 74 are provided at the inlet 52 and the return air port 72, respectively.
The supply of the air-conditioned air from the air-conditioning room 31 to the aging room 54 and the supply of the air-conditioned air from the aging room 54 to the air-conditioned room 31 are adjusted by opening and closing the air conditioners. In the aging chamber 54, a new replacement HEPA pretreatment filter 48 ', 48' is provided in the same manner as in the first embodiment.
, And HEPA filters 50 ', 50', and a chemical filter 76 for removing boron is provided further downstream (left side in the figure). The conditioned air introduced from the intake 52 into the aging chamber 54 is supplied to the HEPA pretreatment filters 48 ', 48', and HE.
After passing through the PA filters 50 ′, 50 ′,...
8 Upstream.

The operation of the third embodiment of the air conditioner for a clean room according to the present invention configured as described above is as follows. First, as in the first embodiment, HEPA pre-treatment filters 48, 48, ... and HEPA filters 50, 50, ..., which have been ventilated for about one month, are installed in the air-conditioned room 31. On the other hand, in the aging chamber 54, a new replacement HEPA pretreatment filter 48 ', 48'.
The PA filters 50 ', 50' ... are installed.

Next, the fans 38, 38 are driven in this state. The air-conditioning room 3 is drawn from the suction port 32 by the fans 38 and 38.
The outside air introduced into 1 is a dust removal filter 40 → a chemical filter 42 → a cooling coil 44 → a reheating coil 46 →
After passing through the humidifier 47 → the HEPA pretreatment filter 48 → the HEPA filter 50, it is guided into the clean room.

On the other hand, a part of the conditioned air that has passed through the humidifier 47 is guided from the intake 52 into the aging chamber 54.
The air-conditioned air guided into the aging chamber 54 passes through a new replacement HEPA pretreatment filter 48 ′ and HEPA filter 50 ′, then passes through the chemical filter 76, and is again guided to the air-conditioned chamber 31. At this time, boron generated in the HEPA pre-processing filter 48 ′ and the HEPA filter 50 ′ is removed by the chemical filter 76.

In this state, the air conditioner 70 is operated for about one month, and when the amount of boron generated from the replacement new HEPA pretreatment filter 48 'and HEPA filter 50' is reduced, the dampers 60 and 74 are closed. As in the first embodiment, the replacement new HEPA pretreatment filter 48 'and HEPA filter 50' are stored in this state, and when the filter is replaced at the time of the periodic inspection of the air conditioner 70, the air conditioning room is replaced. The HEPA pre-processing filter 48 and the HEPA filter 50 which have been used up to now are installed in the inside 31.

As described above, according to the clean room air conditioner of the third embodiment, like the clean room air conditioner of the first embodiment, the HEPA pre-treatment filter 48 and the HEPA filter 50 are replaced. , Pre-aged HEPA pre-processing filter 48 'and HEPA
Since the filter 50 'can be used, the high-concentration boron generated in the early stage of operation is not sent to the clean room as in the related art. Moreover, in the clean room air conditioner 70 of the third embodiment, the air conditioning air guided to the aging chamber 54 does not need to be guided to a space other than the clean room unlike the first embodiment, so that the apparatus itself is simplified. it can.

In the first to third embodiments, the opening and closing of the dampers 60, 62, 66, 74 are manually operated, but the amount of boron generated in the aging chamber 54 is controlled. A sensor for detection may be provided, and automatic control may be performed in conjunction with the sensor. That is, when the measured value of the sensor reaches a predetermined value, the control device automatically opens and closes the dampers 60, 62, 66, and 74.
Thereby, the replacement HEPA pre-processing filter 48 ',
The management of the HEPA filter 50 'becomes easy.

[0036]

As described above, according to the present invention,
Since contaminants generated from the filter are not sent into the clean room in the initial stage of operation, a clean room with extremely high cleanliness can be provided. In addition, since a new filter for replacement can be aged during normal operation of the air conditioner, it is efficient and does not require a special aging device.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment of a clean room air conditioner according to the present invention.

FIG. 2 is a configuration diagram of a second embodiment of a clean room air conditioner according to the present invention.

FIG. 3 is a configuration diagram of a third embodiment of a clean room air conditioner according to the present invention.

FIG. 4 is an explanatory diagram of a clean room to which the air conditioner for a clean room according to the present invention is applied;

FIG. 5 is a configuration diagram of a conventional clean room air conditioner.

FIG. 6 is a graph showing the relationship between the ventilation time of a HEPA filter and the amount of boron generated.

[Explanation of symbols]

 28, 61, 70 ... air conditioner for clean room 30 ... casing 31 ... air conditioning room 48 ... HEPA pre-treatment filter 48 '... new HEPA pre-treatment filter for replacement 50 ... HEPA filter 50' ... new HEPA filter for replacement 54 ... aging Room

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Junta Hirata 1-1-1 Uchikanda, Chiyoda-ku, Tokyo Inside Hitachi Plant Construction Co., Ltd. (72) Inventor Masataka Kasai 1-1-1, Uchikanda, Chiyoda-ku, Tokyo No. 14 Within Hitachi Plant Construction Co., Ltd. (56) References JP-A-3-271645 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24F ^7/ 00-7/00 101

Claims (2)

(57) [Claims] A clean room air conditioner for supplying air-conditioning air to a clean room via a dust filter is provided with an aging section for installing a new replacement dust filter in a casing of the air conditioner body, and installed in the aging section. By passing a part of the air-conditioning air through the new replacement dust removal filter and guiding it to a space other than the clean room, the replacement new dust removal filter is aged to remove contaminants generated from the dust removal filter. A clean room air conditioner characterized by being removed. 2. The air conditioner for a clean room according to claim 1, wherein the air-conditioning air passed through a new filter for replacement installed in the aging unit is circulated again in the air conditioner.