JP2009291675A - Chemical filter and clean room - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chemical filter that can effectively adsorb/remove pollutants contained even in low-humidity air, and a clean room equipped with the same. <P>SOLUTION: The chemical filter 6 comprising an adsorbent 21 that adsorbs and removes pollutants contained in air passing therethrough and supplies air 27 cleaned with the adsorbent 21 includes, as the adsorbent 21, a processed object of protection prepared by processing an object of protection which is manufactured or used in ambient air whereinto the cleaned air 27 is supplied and is adversely affected by adsorbing the pollutants, and a cooling device 22 for cooling the adsorbent 21 and/or air 28 to be supplied to the adsorbent 21. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a chemical filter and a clean room equipped with the same.

  Conventionally, for example, in clean rooms for production and development of semiconductors and liquid crystal devices, it is necessary to reduce the concentration of various molecular and gaseous pollutants in the room air. In particular, plastic materials for resins such as DBP and DOP that diffuse into the room from clean room components, indoor equipment, chemicals used, etc., antioxidants such as BHT, flame retardants such as phosphate esters, low molecular cyclic siloxanes Is easily adsorbed on the surface of silicon wafers and glass substrates for liquid crystal panels (objects to be protected) and adversely affects electrical characteristics such as increase in leakage current and decrease in dielectric strength. ing.

  In order to remove these molecular and gaseous pollutants, air is filtered through a chemical filter equipped with an adsorbent such as activated carbon to supply air into the clean room. However, when activated carbon or the like is used as an adsorbent for a chemical filter, a substance that is difficult to adsorb on a silicon wafer or a glass substrate is also adsorbed and removed together with a contaminant to be removed. For this reason, there existed a problem that the performance of adsorbent fell early, and replacement | exchange of an adsorbent was needed frequently, and the increase in running cost was caused.

On the other hand, the inventors of the present application have proposed that the semiconductor (protection target) of a silicon wafer or a glass substrate is miniaturized and this chip is used as an adsorbent (adsorbent) of a chemical filter (for example, (See Patent Document 1 and Patent Document 2). And in this chemical filter, while the air containing a contaminant passes, only the contaminant which has a bad influence on a silicon wafer or a glass substrate is selectively adsorbed and removed by an adsorbent. Thereby, it is possible to prevent the performance of the adsorbent from deteriorating early while reducing the concentration of contaminants in the air of the clean room.
JP 2004-84971 A JP 2005-118744 A

  On the other hand, organic EL is expected to spread from the technical trend of flat panel displays. In addition, the development of high-performance batteries is proceeding at a rapid pace due to the spread of portable devices. In addition, in order to manufacture these organic EL and high-performance batteries, in addition to removing molecular and gaseous pollutants, a clean room controlled to low humidity is required.

  Thus, when controlling a clean room to low humidity, when low humidity air passes a chemical filter, there exists a possibility that the surface moisture content of adsorption agent may reduce and the removal effect of a pollutant may fall. In other words, the phenomenon of adsorption of contaminants to the adsorbent formed by miniaturizing a silicon wafer or glass substrate is caused by the fact that the moisture (adsorbed water) on the surface of the adsorbent functions as a kind of binder. Passing through and desorbing adsorbed water from the surface of the adsorbent may reduce the performance of the adsorbent (contaminant removal effect).

  In view of the above circumstances, the present invention aims to provide a chemical filter capable of effectively adsorbing and removing pollutants contained in low-humidity air and a clean room including the same. To do.

  In order to achieve the above object, the present invention provides the following means.

  The chemical filter of the present invention includes an adsorbent that adsorbs and removes contaminants contained in the air passing therethrough, and is a chemical filter for supplying air cleaned by the adsorbent. Processed or used in an air environment to be supplied and having a negative effect due to adsorption of the pollutant, the processed protective object is provided as the adsorbent, and the adsorbent and / or the A cooling device for cooling the air supplied to the adsorbent is provided.

  In the present invention, a protected object such as a silicon wafer or a glass substrate that is produced or used (developed) in an air environment that supplies purified air is processed, and the processed protected object is used as an adsorbent. Yes. Thereby, while air containing pollutants passes, only the pollutants that adversely affect can be selectively adsorbed and removed by the adsorbent, reducing the concentration of pollutants in the air such as clean rooms, It is possible to prevent the performance of the adsorbent from deteriorating early.

  Further, the adsorption phenomenon of the contaminant on the adsorbent is an exothermic phenomenon, and the adsorption rate and the adsorption amount of the contaminant on the adsorbent increase as the temperature decreases. For this reason, by cooling the adsorbent and / or air supplied to the adsorbent with the cooling device, the adsorption speed and quantity of contaminants can be increased, the adsorption performance can be improved, and contaminants can be removed reliably. become.

  Furthermore, at this time, even when the air supplied to the adsorbent has a low humidity, the cooling device cools the adsorbent and / or the air supplied to the adsorbent so that the air passing through the chemical filter is near the dew point. By cooling, it is possible to prevent the adsorbed water from being taken away from the surface of the adsorbent, and to ensure the performance of the adsorbent (contaminant removal effect). Further, by cooling the low-humidity air to the vicinity of the dew point with the cooling device in this way, moisture in the low-humidity air is condensed in the chemical filter with a small amount of water. For this reason, the chemical filter also functions as a moisture trap and is effective in maintaining a low humidity air environment.

  In the chemical filter of the present invention, the temperature and humidity sensor for measuring the temperature and humidity of the air supplied to the adsorbent and / or the passing air, and the cooling device based on the measurement result of the temperature and humidity sensor. It is desirable to include a control device that controls driving.

  In this invention, based on the measurement result of the temperature / humidity sensor, the controller controls the driving of the cooling device, that is, the temperature of the adsorbent and / or the air supplied to the adsorbent, and hence the temperature of the air passing through the chemical filter. The This makes it possible to reliably and accurately remove contaminants that adversely affect the object to be protected from the air.

  The clean room of the present invention is characterized by comprising the above-described chemical filter.

  In the present invention, since the chemical filter is provided, the concentration of contaminants in the air can be reliably reduced even when the clean room is controlled at low humidity.

  According to the chemical filter and clean room of the present invention, the chemical filter is provided with the processed protection object as an adsorbent, so that compared with the case where activated carbon is used as the adsorbent (adsorbent) of the chemical filter, It is possible to selectively remove contaminants that are easily adsorbed on a protection target such as a silicon wafer or a glass substrate. As a result, the performance of the adsorbent does not deteriorate early, and the running cost can be reduced.

  In addition, since the chemical filter is equipped with a cooling device, the adsorption speed and amount of contaminants increase, the adsorption performance can be improved, the contaminants can be reliably removed, and the adsorbent is supplied. Even when the air has a low humidity, it is possible to prevent the adsorbed water from being taken away from the surface of the adsorbent, and to ensure the effect of removing contaminants. Furthermore, the chemical filter functions as a moisture trap and is effective in maintaining a low humidity air environment.

  Hereinafter, with reference to FIG.1 and FIG.2, the chemical filter which concerns on one Embodiment of this invention, and a clean room provided with the same are demonstrated. The present embodiment relates to a chemical filter for maintaining the air environment of a clean room for production / development of semiconductors and liquid crystal devices, for example, with a predetermined cleanliness, and a clean room equipped with the same.

  As shown in FIG. 1, in the clean room 1 (1 a) of the present embodiment, the outside air 3 is sucked into the air conditioner 2 through the medium performance filter 4 as the air conditioner 2 is driven. To the first high-performance filter 5, such as ULPA and HEPA, the chemical filter 6, and the second high-performance filter 7, which are sequentially filtered and supplied with purified air. In addition, a part of the air is exhausted 8 from the clean room 1a (1), and a large amount of air in the clean room 1a (1) is returned to the supply side as circulating air 10 along with the driving of the blower 9. The circulating air 10 is purified through the third high performance filter 11 and joined to the freshly sucked outside air 3.

  On the other hand, the chemical filter 6 of this embodiment is provided in a state attached to the second high-performance filter 7 as shown in FIG. 1, and as shown in FIG. 2, the casing 20, the adsorbent 21, the cooling device 22, and the like. A control device 23 and a temperature / humidity sensor 24 (temperature sensors 24a, 24b, humidity sensors 24c, 24d) are provided.

  The casing 20 is formed using a material having excellent thermal conductivity such as metal, for example, and a duct (air conditioner side duct 25) connected to the first high performance filter 5 is provided at one end side, and the second high performance filter 7 is provided. The duct (clean room side duct 26) connected to is connected to the other end side in communication with each other.

  The adsorbent 21 is obtained by processing an object to be protected that is produced or used in an air environment that supplies purified air. That is, in this embodiment, the adsorbent 21 is produced or used in the clean room 1a (1). A silicon wafer, a glass substrate, or the like is refined by processing it into a plate shape or by crushing, and is filled in a state where an appropriate gap is formed inside the casing 20. Since the adsorbent 21 is proportional to the specific surface area, the adsorbent 21 exhibits excellent adsorption performance as it is finely processed. However, if it is too fine, the pressure loss of the air passing through the gap is reduced. Increases energy load. For this reason, it is desirable that the adsorbent 21 is formed with a particle size of about 0.1 mm to 3 mm.

  The cooling device 22 is formed using a Peltier element, for example, and is provided so as to surround the casing 20. Further, the cooling device 22 is connected to a control device 23 such as a personal computer, and the drive of the cooling device 22 is controlled by the control device 23. Further, a pair of temperature / humidity sensors 24, that is, temperature sensors 24 a and 24 b and humidity sensors 24 c and 24 d are disposed in the air-conditioner side duct 25 and the casing 20, and are connected to the control device 23.

  Next, operations and effects of the chemical filter 6 having the above-described configuration and the clean room 1 including the chemical filter 6 will be described.

  In the clean room 1 of the present embodiment, the outside air 3 is sucked into the air conditioner 2 through the medium performance filter 4 by driving the air conditioner 2, and the outside air 3 is filtered by the first high performance filter 5 and the blower 9. The circulating air 10 returned from the clean room 1 a (1) is merged by driving and is supplied to the chemical filter 6 through the air-conditioner side duct 25.

  At this time, since the adsorbent 21 of the chemical filter 6 is a thin piece such as a silicon wafer or a glass substrate that is produced or used in the clean room 1a (1), the molecular or gaseous state supplied to the adsorbent 21 Air 28 containing contaminants passes through the gaps of the adsorbent 21 and only the contaminants adsorbed on the silicon wafer or glass substrate are selectively adsorbed. Accordingly, contaminants that are adsorbed on the silicon wafer or the glass substrate and are adversely affected are reliably adsorbed and removed, and other substances that do not have an adverse effect are not adsorbed on the adsorbent 21. Will not decline early.

  Moreover, in this embodiment, each temperature of the air (air supplied to the adsorption body 21) which distribute | circulates the air-conditioner side duct 25, and the air (air which passes the chemical filter 6) which passes the clearance gap between adsorption bodies 21 is shown. And humidity are measured by the temperature / humidity sensor 24. Further, the driving of the cooling device 22 is controlled by the control device 23 based on the measurement results of the temperature / humidity sensor 24, and the air passing through the casing 20, the adsorbing body 21, and further the gap between the adsorbing bodies 21 is controlled by the cooling device 22. Cooled to temperature. And since the adsorption | suction phenomenon of the pollutant to the adsorption body 21 increases adsorption speed and adsorption amount, so that it is low temperature, by cooling the adsorption body 21 with the cooling device 22, the adsorption speed | rate and adsorption amount of a pollutant. Increase, the adsorption performance is improved, and contaminants are reliably removed.

  Furthermore, based on the measurement result of the temperature / humidity sensor 24 as described above, the control device 23 controls the driving of the cooling device 22 (the temperature of the adsorbent 21 and the temperature of the air that passes through the chemical filter 6), whereby a silicon wafer is obtained. Contaminants that adsorb and adversely affect the glass substrate or the like are reliably and accurately removed from the air. And the air which passed the chemical filter 6 in this way is filtered by the 2nd high performance filter 7, and the air cleaned with high precision is supplied to the clean room 1a (1).

  On the other hand, for example, the humidity of the air is adjusted by an air conditioner or a humidity adjusting device (not shown) provided between the first high-performance filter 5 and the chemical filter 6 to control the clean room 1a (1) to a low humidity. In this case, for example, the ultra-low humidity air 28 having a dew point of −40 ° C. and a relative humidity of 1% or less at 23 ° C. passes through the chemical filter 6, and the surface moisture content of the adsorbent 21 is reduced. There is a risk that the effect of removing pollutants will be reduced.

  On the other hand, in this embodiment, since the temperature and humidity of the low-humidity air 28 supplied to the adsorbent 21 are measured by the temperature / humidity sensor 24, based on the measurement result of the temperature / humidity sensor 24, The controller 23 controls the driving of the cooling device 22 so as to cool the air passing through the chemical filter 6 to near the dew point. When the air cooled to the vicinity of the dew point by the cooling device 22 passes through the inside of the casing 20 (the gap between the adsorbent bodies 21), even if the air has an extremely low humidity, a very small amount is present on the surface of the adsorbent body 21. A film of condensed water is formed. As a result, the adsorbed water is not taken away from the surface of the adsorbent 21, and the adsorption and removal of the pollutant is promoted using the condensed water as a binder, and the performance of the adsorbent 21 (contaminant removal effect) is ensured. In addition, since the moisture in the low-humidity air 28 is condensed in the chemical filter 6 (casing 20), the chemical filter 6 also functions as a moisture trap, and the clean room 1a (1) It is also effective for maintaining a low humidity air environment.

  Here, since the change in humidity is large in a general room, if air is cooled to the vicinity of the dew point in this way, a large amount of dew condensation water may be generated in some cases, which may cause problems. The humidity sensor 24 measures the temperature and humidity of the air, and the control device 23 controls the driving of the cooling device 22 and the cooling temperature of the air based on the measurement result. In the clean room 1a (1), since uniform temperature and humidity control is originally performed, control of the dew point that causes dew condensation can be performed relatively easily. For this reason, a large amount of condensed water is not generated on the surface of the adsorbent body 21 so as to inhibit the adsorption of the pollutant substance, and the adsorbent body 21 selectively removes the pollutant with certainty.

  Therefore, in the chemical filter 6 of the present embodiment and the clean room 1 including the same, the silicon wafer or glass substrate (protection) in which the chemical filter 6 is produced or used (developed) in an air environment that supplies purified air. By processing the target object) and providing the processed protection target as the adsorbent 21, the air 28 containing the pollutant passes through and only the pollutant that adversely affects the adsorbent 21 is selectively adsorbed. Thus, it is possible to prevent the performance of the adsorbent 21 from deteriorating early while reducing the concentration of contaminants in the air of the clean room 1. Thereby, compared with the case where activated carbon etc. are used for the adsorbent (adsorbent body) of a chemical filter, it is not necessary to replace | exchange the adsorbent body 21 frequently, and it becomes possible to reduce a running cost.

  Further, by cooling the adsorbent 21 with the cooling device 22, the adsorption speed and the adsorption amount of the contaminants are increased, the adsorption performance is improved, and the contaminants can be reliably removed.

  Furthermore, even when the air 28 supplied to the adsorbent 21 has a low humidity, the adsorbent 21 is cooled by the cooling device 21 so that the air passing through the chemical filter 6 is cooled to the vicinity of the dew point. It is possible to prevent the adsorbed water from being deprived from the surface, and to secure the performance of the adsorbent 21. Further, by cooling the low-humidity air to the vicinity of the dew point by the cooling device 22 in this way, moisture in the low-humidity air is condensed in the chemical filter 6 with a slight amount of water. For this reason, the chemical filter 6 also functions as a moisture trap, and is effective in maintaining a low humidity air environment.

  Further, based on the measurement result of the temperature / humidity sensor 24, the control device 23 drives the cooling device 22, that is, the temperature of the adsorbent 21 and / or the air 8 supplied to the adsorbent 21 and thus the air passing through the chemical filter 6. By controlling the temperature, it is possible to reliably and accurately remove contaminants that adversely affect the object to be protected from the air.

  As mentioned above, although one embodiment of the chemical filter according to the present invention and a clean room using the same has been described, the present invention is not limited to the one embodiment described above, and can be appropriately changed without departing from the spirit of the present invention. is there. For example, in the present embodiment, the cooling device 22 is provided so as to surround the casing 20, and the air passing through the chemical filter 6 is cooled by cooling the adsorbent 21 by the cooling device 22. A cooling device 22 may be provided in the air conditioner side duct 25 (upstream in the air flow direction with respect to the adsorbent body 21), and the air 28 supplied to the adsorbent body 21 may be cooled in advance. Even in this case, since the air passing through the chemical filter 6 is cooled, it is possible to obtain the same effect as in the present embodiment.

  Further, the adsorbent 21 is not necessarily filled in the casing 20 to form the chemical filter 6. For example, the adsorbent 21 is used by using an adhesive for the high performance filter (second high performance filter 7). The chemical filter may be configured by fixing them together.

  Further, for example, the adsorbent 21 and the photocatalyst may be mixed and accommodated in the casing 20, or the adsorbent 21 with the photocatalyst fixed may be filled in the casing 20. By irradiating light, it becomes possible to decompose and remove the contaminants adsorbed on the adsorbent body 21, thereby extending the life of the adsorbent body 21 and further reducing the running cost. Thus, it is possible to improve the efficiency of maintenance management.

It is a figure which shows the clean room which concerns on one Embodiment of this invention. It is a figure which shows the chemical filter which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Clean room 1a Clean room 2 Air conditioner 3 Outside air 4 Medium performance filter 5 1st high performance filter 6 Chemical filter 7 2nd high performance filter 8 Exhaust 9 Blower 10 Circulating air 11 3rd high performance filter 20 Casing 21 Adsorbent 22 Cooling device 22a Cooling device power supply 23 Control device 24 Temperature / humidity sensor 25 Air conditioner side duct 26 Clean room side duct 27 Cleaned air 28 Air supplied to the adsorbent

Claims (3)

A chemical filter comprising an adsorbent that adsorbs and removes contaminants contained in air passing therethrough, and for supplying air purified by the adsorbent,
Produced or used in an air environment that supplies the purified air, processes a protection object that has an adverse effect due to adsorption of the contaminants, and includes the processed protection object as the adsorbent,
A chemical filter comprising a cooling device for cooling the adsorbent and / or air supplied to the adsorbent. The chemical filter according to claim 1,
A temperature / humidity sensor for measuring the temperature and humidity of the air supplied to the adsorbent and / or the passing air, and a control device for controlling the driving of the cooling device based on the measurement result of the temperature / humidity sensor. A chemical filter characterized by   A clean room comprising the chemical filter according to claim 1 or 2.

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