JP2010121909A - Method of removing gaseous contaminant within clean room - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a removing method capable of inexpensively reducing a concentration of gaseous contaminant within a clean room. <P>SOLUTION: In the method of removing the gaseous contaminant 44 within the clean room 10 including at least one purification area 12A and a return area 12B formed therein, hot air is introduced into the inside of the clean room 10 via an external air conditioner 34 including a filter 40 and a heater 42, the temperature inside the clean room 10 is made high to volatilize the gaseous contaminant 44, and the volatilized gaseous contaminant 44 and hot air are discharged to outside of the clean room 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for reducing the concentration of gaseous pollutants generated in a clean room.

  In a semiconductor manufacturing factory or the like, a clean room is used to make a production area a highly clean space. However, in a clean room, gaseous pollutants adhere from clean room constituent materials such as electric wires, wall joint materials, floor materials, and manufacturing equipment, and have an adverse effect on products.

  Therefore, Patent Document 1 below describes a clean room system provided with gaseous impurity removing means for removing gaseous pollutants contained in the outside air and / or circulating air.

The block diagram which shows the conventional clean room equipment 401 is shown in FIG. The clean room facility 401 adjusts the temperature of the outside air by the air conditioner 434 and is sent into the clean room 410 through the filter 440. The air is fed clean air through a chemical filter 426 and a fine filter unit (FFU) 420 in the clean room 410. The chemical filter 426 removes gaseous contaminants. Then, the hot air is cooled and circulated to the ceiling space 422 by the dry coil 450 in the return area 12 </ b> B that is a double wall from the room under the grating 414 through the grating 414. Part of the circulating air is discharged to the outside through the exhaust damper 446.
JP-A-8-89747

  However, a clean room system provided with a gaseous impurity removing means as described in Patent Document 1 may have a chemical filter made of activated carbon or the like as the gaseous impurity removing means, but has a lifetime of about 1 year. Because it was short-lived and expensive, it was not installed much.

  Therefore, in the conventional clean room operation method, gaseous pollutants cannot be removed positively, and an expensive chemical filter is used for the removal, and if it is used, the replacement is necessary. There was a problem of frequent frequency.

  This invention is made | formed in view of such a situation, and it aims at providing the removal method which can reduce the gaseous pollutant density | concentration in a clean room at low cost.

  In order to achieve the above object, claim 1 of the present invention is a method for removing gaseous pollutants in a clean room in which at least one purification area and a return area are formed, and includes an external filter and a heater. Hot air is introduced into the clean room through a conditioner, the gaseous pollutant is volatilized by raising the temperature in the clean room, and the volatilized gaseous pollutant and the hot air are discharged outside the clean room. A method for removing gaseous pollutants in a clean room is provided.

  According to the first aspect, since the outside air is introduced into the clean room as hot air using a heater, the temperature in the clean room can be increased to vaporize gaseous pollutants. And the density | concentration of the gaseous pollutant in a clean room can be reduced by discharging | emitting the volatilized gaseous pollutant and the hot air introduce | transduced in the clean room.

  A second aspect of the present invention is characterized in that, in the first aspect, the return area includes a circulation path shielding plate.

  According to the second aspect, since the return path is provided with the circulation path shielding plate, it is possible to prevent the hot air introduced into the purification area and including the gaseous pollutant from circulating in the clean room again.

  A third aspect is characterized in that, in the first or second aspect, the hot air is adjusted by the heater so that the temperature in the clean room becomes 30 to 50 ° C.

  According to the third aspect, the gaseous substance can be efficiently volatilized by setting the temperature in the clean room within the above temperature range.

  A fourth aspect of the present invention is characterized in that, in any one of the first to third aspects, the gaseous pollutant discharged from the clean room and the hot air are returned to the external air conditioner through a gaseous pollutant collecting device. To do.

  According to the fourth aspect, the hot air exhausted from the clean room is returned to the external air conditioner again. Since the outside air exhausted from the clean room has a high temperature, energy to be heated can be reduced, so that energy saving can be achieved. In addition, since the gaseous pollutant collecting device is passed before returning to the external air conditioner, the gaseous pollutant in the hot air can be removed.

  A fifth aspect of the present invention provides the method according to any one of the first to fourth aspects, wherein the ceiling, floor, wall, and device in the clean room are covered with a sheet-like adsorbent, the volatilized gaseous pollutant is adsorbed on the adsorbent, and the adsorption It is characterized by removing the material.

  According to the fifth aspect, by covering the ceiling, floor, wall, and apparatus in the clean room with the sheet-like adsorbent, the volatilized gaseous pollutant can be adsorbed on the adsorbent. Then, by removing the adsorbent adsorbed with the gaseous pollutant, the gaseous pollutant can be reliably removed.

  According to the present invention, hot air is sent into a clean room, the temperature in the clean room is raised, and gaseous pollutants are actively volatilized. And exhausting a gaseous pollutant simultaneously with a hot air can reduce the gaseous pollutant in a clean room.

  A preferred embodiment of a method for removing gaseous pollutants in a clean room of the present invention will be described below with reference to the accompanying drawings. The present invention is performed in order to reduce the concentration of gaseous contaminants (hereinafter abbreviated as “AMC”) in the clean room during the proposed maintenance for stopping the clean room for a long period of time.

  The gaseous pollutants to be removed in the present invention are volatile organic compounds such as aliphatic esters, phthalates (DBP, DOP, etc.) and cyclic siloxanes.

<< First Embodiment >>
FIG. 1 is a schematic diagram of a clean room facility 1 used in the method for removing gaseous pollutants of the present invention.

  A clean room facility 1 shown in FIG. 1 includes a clean room 10 and an external air conditioner 34 that is an air conditioner. The external air conditioner 34 adjusts the taken-in air to a temperature required by the clean room 10 and supplies the adjusted air into the clean room 10 via the duct 36. The external air conditioner 34 includes a blower 38, a filter 40, and a heater 42 in a predetermined position.

  The clean room 10 has a room 12 with side walls partitioned by walls, and a purification area 12A is formed inside, and return areas 12B are formed on both sides of the purification area 12A. Inside the room 12, for example, a device 32 for processing or cleaning a semiconductor wafer is provided. The return area 12B is provided with a dry coil 50 that cools the passing air by sensible heat exchange with the heat medium. The temperature of the circulating air can be adjusted by the dry coil 50. In addition, although this embodiment demonstrates the clean room 10 in which the purification area 12A was formed in the center and the return areas 12B were formed on both sides of the purification area 12A, the present invention is not limited to this.

  The floor surface of the room 12 is constituted by a grating 14 having a large number of through holes, and an underfloor space 16 is formed below the grating 14. In the present embodiment, an example in which the underfloor space 16 is formed on the lower side of the room 12 will be described. However, the present invention is not limited to this, and there is no facility (that is, the floor surface of the room 12 has no holes). If applicable).

  On the ceiling surface of the room 12, a lattice-like ceiling frame 18 in which beams are combined vertically and horizontally is provided. An FFU (fine filter unit) 20 is provided in the lattice portion of the ceiling frame 18 and above the purification area 12A. Although the internal structure of the FFU 20 is not shown, it is composed of a vertically opened casing and a fan and a filter installed in the casing. By driving the fan, the air in the ceiling space 22 is sucked into the casing. The sucked air is removed by the filter and is down-flowed to the purification area 12A of the room 12. The FFU 20 is thinned and disposed, and the remaining lattice portion of the purification area 12 </ b> A is closed by a closing plate 24.

  The air that has flowed down to the purification area 12 </ b> A is sucked into the underfloor space 16 through the grating 14. This air flows through the underfloor space 16 to both sides.

  In the present invention, the outside air is heated by the heater 42 of the external air conditioner 34 to become hot air, and the inside of the purification area 12A can be heated to a high temperature. Therefore, AMC 44 can be volatilized from organic substances in members such as walls, floors, ceilings, electric wires, and devices, and the purification area 12A can be in a high concentration state of AMC 44. The temperature in the purification area 12A is preferably 30 ° C. or more and 50 ° C. or less. The temperature is preferably high, but in the case of an existing clean room, if the temperature is too high, there is a thermal elongation of a structural member, a manufacturing apparatus, etc., so the upper limit is preferably 50 ° C. When a clean room is newly installed and no manufacturing equipment is installed in the clean room, the heat resistance temperature of organic materials (plastics such as PVC pipes and cables, sealing materials, etc.) used in the clean room, and thermal expansion of structural members, etc. Can be set in a range that does not affect the building. Outside air is heated by the external air conditioner 34 so that the inside of the purification area 12A falls within the above temperature range. By setting the temperature in the purification area 12A within the above temperature range, the AMC 44 can be volatilized efficiently. Moreover, since the AMC 44 adsorbed on the FFU 20 can be volatilized by setting the FFU 20 to the operating state, it can be volatilized in the purification area 12A.

  If the state is kept as it is, the AMC 44 is reattached to the clean room, and therefore the exhaust damper 46 immediately exhausts the air to the outdoors. The lattice portion of the ceiling frame 18 above the return area 12B is not closed during clean room operation, but is an opening, but when removing gaseous pollutants, a circulation path shielding plate 48 is installed, Hot air is not circulated. Therefore, the hot air flowing on both sides of the underfloor space 16 is exhausted from the exhaust damper 46 across the return area 12B as it is.

  The above-described operation of introducing hot air into the purification area 12A and exhausting it from the exhaust damper 46 together with the AMC 44 is repeated until the AMC concentration in the purification area 12A decreases.

  Moreover, even if it does not perform high temperature operation until the AMC density | concentration in washing | cleaning area 12A reduces, you may drive | operate for about 8 hours, for example. AMC can be volatilized by lengthening the operation time.

  After the high temperature operation is completed, it is preferable to immediately remove the circulation path shielding plate 48 in the return area 12B and return to the normal operation. This is because if the high temperature operation is carried out for a long time, not only the AMC from the organic matter but also the AMC attached to the other members volatilizes.

  In the state returned to the normal operation, the AMC concentration is reduced as compared to before the high temperature state. A relatively large amount of AMC adheres to the filter and AMC is also released from the filter into the purification area 12A. However, since the amount of adhesion is small, the amount of AMC released can be reduced during normal operation, and the purification area 12A. The AMC concentration inside can be reduced.

<< Second Embodiment >>
FIG. 2 is a schematic diagram showing a second embodiment of the clean room facility 101 used in the method for removing gaseous pollutants of the present invention.

  The clean room facility 101 shown in FIG. 2 is different from the first embodiment in that a circulation path 110 is provided outside the clean room 10 and the air exhausted from the clean room 10 passes through the circulation path 110 and is returned to the external air conditioner 134. Yes.

  According to the clean room facility 101 shown in the second embodiment, high-temperature air can be returned to the external air conditioner 134 without lowering the temperature, so that energy for heating the outside air can be reduced, thus saving energy. And the cost can be reduced.

  In the middle of the circulation path 110, an AMC collection device 112 is provided. Since the air discharged from the clean room 10 contains AMC, it passes through the AMC collection device 112 to remove AMC. As the AMC collection device 112, activated carbon can be used.

  After the removal of AMC, the circulation path shielding plate 48 is removed and the operation is returned to the conventional operation. At this time, the high-temperature air circulation path 110 and the AMC collection device 112 used for AMC removal can also be used as devices attached to the clean room 10.

<< Third Embodiment >>
FIG. 3 is a schematic diagram showing a third embodiment of a clean room facility 201 used in the method for removing gaseous pollutants of the present invention.

  A clean room facility 201 shown in FIG. 3 is different from the first embodiment in that the surfaces of walls, floors, ceilings, devices, and the like in the clean room 10 are covered with a sheet-like adsorbent 210 that hardly generates AMC.

  By covering the wall, floor, ceiling, device, etc. with the adsorbent 210, the AMC volatilized by the hot air in the clean room 10 can be adsorbed by the adsorbent 210. Further, by returning to the normal operation of 25 ° C., the volatilized AMC can be further adsorbed on the adsorbent 210. And the AMC density | concentration in a clean room can be reduced by carrying out the adsorbent 210 which this AMC adsorb | sucked out of the clean room 10. FIG.

  As the adsorbent 210, a sheet-like material is used, and a sheet of metal foil, aluminum, SUS, or the like can be used. As the organic sheet, hydrocarbons such as Teflon (registered trademark) and polyethylene can be used. Moreover, the same glass wool as a filter raw material can also be used.

<< Fourth Embodiment >>
FIG. 4 is a schematic view showing a fourth embodiment of a clean room facility 301 used in the method for removing gaseous pollutants of the present invention.

  The clean room facility 301 shown in FIG. 4 is a method when the clean room 10 is newly installed. The components used when installing in a clean room are manufactured using low outgassing members, but some AMC still volatilizes. Therefore, after completion or during the performance inspection period, the FFU 20 is stopped and the circulation path shielding plate 48 is installed in the return area 12B.

  Then, heated outside air (hot air) is introduced into the clean room 10. At this time, the closing plate normally installed in the portion of the ceiling frame 18 where the FFU 20 is not provided is removed.

  And hot air is introduce | transduced into the purification | cleaning area 12A from the lattice part which removed the closing plate. Moreover, it is preferable to cover the wall, floor, ceiling, etc. in the clean room 10 with the adsorbent 210. As the adsorbent 210, the same material as that used in the third embodiment can be used.

  The AMC 44 in the clean room 10 is volatilized by the hot air and is adsorbed by the adsorbent 210 or discharged out of the clean room 10 together with the hot air. The adsorbent 210 is carried out outdoors after the normal temperature of 25 ° C. in the clean room.

  As described above, after the clean room is installed and before the normal operation is performed, AMC that volatilizes can be removed from the components in the clean room 10 by performing the above operation method, thus providing a clean room with low outgas. can do.

It is a schematic diagram which shows the clean room equipment of the gaseous pollutant removal method of 1st Embodiment. It is a model diagram which shows the clean room equipment of the gaseous pollutant removal method of 2nd Embodiment. It is a model diagram which shows the clean room equipment of the gaseous pollutant removal method of 3rd Embodiment. It is a model diagram which shows the clean room equipment of the gaseous pollutant removal method of 4th Embodiment. It is a model drawing which shows the conventional clean room equipment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 101, 201, 301 ... Clean room equipment, 10 ... Clean room, 12 ... Room, 12A ... Purification area, 12B ... Return area, 14 ... Grating, 16 ... Under floor space, 18 ... Ceiling frame, 20 ... Fine filter unit (FFU) ), 22 ... Ceiling space, 24 ... Closure plate, 32 ... Device, 34 ... External air conditioner, 36 ... Duct, 38 ... Blower, 40 ... Filter, 42 ... Heater, 44 ... Gaseous contaminant (AMC), 46 ... exhaust damper, 110 ... circulation path, 112 ... AMC collector, 210 ... adsorbent

Claims (5)

A method for removing gaseous pollutants in a clean room in which at least one purification area and a return area are formed,
Hot air is introduced into the clean room through an external air conditioner equipped with a filter and a heater, and the temperature in the clean room is raised to volatilize the gaseous pollutant. A method for removing gaseous pollutants in a clean room, wherein hot air is discharged outside the clean room.   The method for removing a gaseous pollutant in a clean room according to claim 1, wherein a circulation path shielding plate is provided in the return area.   The method for removing gaseous pollutants in a clean room according to claim 1 or 2, wherein the hot air is adjusted by the heater so that the temperature in the clean room becomes 30 to 50 ° C.   The inside of the clean room according to any one of claims 1 to 3, wherein the gaseous pollutant discharged from the clean room and the hot air are passed through a gaseous pollutant collecting device and returned to the external air conditioner. To remove gaseous pollutants.   The ceiling, floor, wall, and device in the clean room are covered with a sheet-like adsorbent, the volatilized gaseous pollutant is adsorbed on the adsorbent, and the adsorbent is removed. 4. The method for removing gaseous pollutants in a clean room according to any one of 4 above.

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