JP7080478B2 - Dry room for gas replacement - Google Patents

Description

The present invention is a drying chamber having a low active gas concentration (hereinafter, a concentration in which the active gas concentration is as close to 0 ppm as possible is referred to as "low active gas concentration") such as a booth in which an organic EL display manufacturing apparatus is installed. In a chamber, a dehumidifying device and gas that can perform maintenance and adjustment of manufacturing equipment in a relatively short time in an environment with a low dew point (hereinafter, a dew point temperature of 0 degrees or less is called a "low dew point"). It relates to a gas replacement system including a refiner.

Conventionally, organic EL elements used in organic EL display devices, which are expected as next-generation flat panel displays to replace liquid crystal displays, are promising for use as solid-state light-emitting inexpensive large-area full-color display devices and write light source arrays. It has been actively researched and developed. However, organic substances such as organic light emitting materials used for organic EL devices and electrodes and the like are vulnerable to moisture, and their performance and characteristics are rapidly deteriorated by the moisture in the air. Therefore, even during the experiments associated with these developments, it is necessary to carry out manufacturing and experiments in a booth where air is purged with air with an extremely low dew point or an inert gas such as nitrogen vaporized from liquid nitrogen.

At present, in the production of organic EL displays (OLEDs), printing technology such as inkjet technology is used to make liquid organic EL materials into uniform thin films on a substrate to create elements with improved production efficiency and performance. Technology is being developed. In order to develop such a manufacturing technique, it is necessary to set the environment of the manufacturing apparatus to a low humidity such as humidity of 1 ppm or less and oxygen of 1 ppm or less and a low active gas concentration. However, when performing maintenance or adjustment of manufacturing equipment in the booth, it is necessary to return the low humidity nitrogen environment to the atmospheric environment (hereinafter referred to as "atmospheric break").

At this time, when the nitrogen environment is replaced with a normal atmosphere, various parts of the internal device adsorb water, and when returning to the nitrogen environment, it takes a very long time for the parts to desorb the adsorbed water.

Patent Document 1 describes a technique for minimizing the internal volume of a gas enclosure assembly in order to minimize the amount of inert gas for returning from the atmospheric break to the nitrogen environment and to minimize the downtime. There is something.

Special Table 2015-510254A

In Patent Document 1, the gas enclosure is framed and the internal volume is made as small as possible to minimize the amount of inert gas in the gas enclosure and to minimize the downtime due to maintenance and the like. Although the work space can be optimized to adapt to the installation area of various OLED manufacturing equipment, the gas purification system for simultaneously purifying the inert gas and removing the moisture that accompanies the pause is also stopped. Therefore, there is a problem that it takes too much time to make the inside of the booth a low humidity and low outgas concentration environment again. In addition, since the gas purification device and the dehumidifying device are in the same mechanism, the purification rate differs between oxygen and water, and it takes longer to remove water than the removal of oxygen, so there is also the problem that it is difficult to remove them at the same time. ..

In order to solve the above problems, the present invention provides an airtight container inside the drying chamber, supplies the low active gas and the low dew point gas to the airtight container, and supplies an inert gas purifier and a low dew point gas supply device. Since each can be controlled independently, if a person enters the airtight container due to adjustment etc., if the supply of low active gas is stopped while maintaining the supply of low dew point air, it will be suspended due to an atmospheric break. The time can be greatly reduced. That is, water molecules are polar substances, and when air is introduced into an airtight container that needs to be maintained at a low dew point, water molecules adhere to the wall surface of the airtight container and the inside of the filter. It is necessary to supply low dew point air for a long time in order to discharge the attached water molecules, but in the case of the present invention, it is possible to maintain the supply of the low dew point gas while the supply of the low active gas is stopped. It is possible to quickly reach a low dew point in the airtight container even after an atmospheric break. In addition, even if it is nitrogen gas that has entered a cylinder as a low inert gas, or even if it is air from which oxygen has been removed, the price of the gas is high, and the cost will increase unless the time for atmospheric break is shortened. On the other hand, since it is not costly to make low dew point gas with a desiccant rotor, the total cost can be reduced by stopping the supply of low active gas while maintaining the supply of low dew point gas and performing maintenance.

In addition, since the mechanism for removing water and oxygen is usually in the same device, the flow rate of the gas flowing through the water removal device and the oxygen removal device is the same, but by using different devices, the respective flow rates can be adjusted. Since it can be changed freely, it has become possible to create a dry room with a low active gas concentration under optimum operating conditions that realize both low humidity and low active gas concentration at the same time.

The gas replacement dry room of the present invention is configured as described above, and is unidirectional (hereinafter referred to as "one pass") without circulating from an air purification filter such as a HEPA filter or ULPA filter installed in the upper part of the container even during an air break. By supplying low dew point air, maintenance, maintenance, setup change, etc. are carried out so that the filter that most easily retains moisture does not retain moisture. In addition, an inert gas purifier and a desiccant dehumidifier are installed in series in the circulation path of the container, a circulation path separated from the circulation path is separately provided, and the circulation path separately provided during the atmospheric break is circulated to circulate. The air was kept away from the atmospheric environment. By doing so, it was possible to significantly shorten the recovery time from the atmospheric environment after the atmospheric break of the container to the environment with low humidity and low active gas concentration. Furthermore, by individually controlling the flow rates of the gas flowing through this dehumidifying device and the inert gas refining device, it is possible to create a dry room that can be easily optimized for an environment with low humidity and low active gas concentration in a short time. Was done.

FIG. 1 is a flow chart in Example 1 of the dry room of the present invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the present embodiment, a gas replacement dehumidifier for a container whose inside needs to be kept clean with a low dew point and a low active gas concentration, and an organic EL display (OLED) using a printing technique such as an inkjet technique as a gas replacement method are manufactured. Alternatively, the container of the research and development device will be described as an example. The present invention is not limited to the manufacture of organic EL displays (OLEDs) or research and development equipment, but develops the fields of lithium-ion battery materials and semiconductors that need to keep the storage space clean with low dew point and low active gas concentration. It can also be used for storage containers such as glove boxes used for this purpose, or for closed spaces.

Hereinafter, Example 1 of the gas replacement dry room of the present invention will be described in detail with reference to FIG. 1 is an airtight container that needs to keep the inside clean with a low dew point and low active gas concentration, and houses the manufacturing equipment 2 used for manufacturing and research and development of organic EL display (OLED), and gas circulation inside. It has a road 4 and an air purification filter 3 such as a HEPA filter and a ULPA filter. The air purification filter 3 may be a plurality of fan filter units. Nitrogen gas and dry air from the dehumidifier 38 are supplied to the container 1 by the pipe A.

The air to be treated in the container 1 is sent to the nitrogen purifier 40 as an inert gas purifier through the pipe B, and oxygen, which is an active gas in the air to be treated, is removed. Reference numeral 5 is a catalyst container for purifying nitrogen, which contains a copper catalyst, a platinum catalyst, and the like. If the catalyst breaks down, the temperature is raised by the heater 6 while flowing nitrogen gas and hydrogen gas to regenerate the catalyst. Reference numeral 7 is a pump for sending the air to be processed to the nitrogen purifier 40, and the purified air to be processed is sent to the desiccant dehumidifier 39 as a low dew point gas supply device by the blower 9 through the cooler 8. In this embodiment, a catalyst such as a copper catalyst or a platinum catalyst is used, but the present invention is not limited to these, and other catalysts containing copper and / or platinum as a main component may be used.

Reference numeral 11 is a honeycomb rotor for the desiccant dehumidifier 39, which is divided into a processing zone 12, a purge zone 13, and a regeneration zone 14. Reference numeral 17 denotes a rotor drive motor such as a geared motor for rotationally driving the honeycomb rotor. The air to be processed is supplied to the processing zone 12 by the blower 9 through the precooler 10. A part of the air to be processed is branched in front of the processing zone 12, passes through the purge zone 13, and then is sent to the regeneration zone 14 through the regeneration heater 36. The air leaving the regeneration zone 14 is cooled by the cooler 15, and the condensed water from the moisture in the regeneration air desorbed from the honeycomb rotor is removed as a drain and returned to the front of the blower 9. The air to be processed leaving the desiccant dehumidifier 39 is heated by the afterheater 16 as needed, and is returned to the container 1 through the pipe D. If the nitrogen gas supply facility has spare capacity, install the desiccant dehumidifier 39 in an airtight room and supply nitrogen gas to the room to prevent the active gas from entering from the desiccant dehumidifier 39. It may be configured to suppress it.

Reference numeral 34 is an airtight drying chamber for accommodating the container 1, which is large enough for a person to enter in the case of adjustment or the like. Dry air is supplied from the dry air supply device 37 from the pipe G, and the drying chamber is supplied from the pipe H. The air of 34 is returned to the dry air supply device 37. The pipe E is an exhaust passage for exhausting the air in the container 1 to the outside of the drying chamber 34. In this embodiment, the honeycomb rotor 11 having the purge zone 13 is used, but the present invention is not limited to this, and a honeycomb rotor divided into a processing zone and a regeneration zone may be used.

First, the operation of the gas replacement dry room of the present invention having the above configuration will be described with respect to nitrogen replacement and circulation operation of the container 1. Valves 18, 19, 21, 22, 23, 24, 25, 27, 28, 29, 30, 31, 33, 35 are opened, and nitrogen gas and dry air are sent from the pipe A to the container 1. When the oxygen concentration in the container 1 drops to 100 ppm or less, the valves 30, 33, and 35 are closed to supply the dry air having a low dew point to the drying chamber 34 from the nitrogen purifier 40, the desiccant dehumidifier 39, and the pipe G. The operation of the dry air supply device 37 that circulates the dry air is started. By adjusting the valves 24 and 25 as necessary, the air volume of the air circulating from the container 1 through the pipe B to the nitrogen purifier 40 and the air volume directly to the desiccant dehumidifier 39 are adjusted. For example, circulation is continued until a specified concentration such as an oxygen concentration of 1 ppm or less and a water concentration of 1 ppm or less is reached, and then the operation of the manufacturing apparatus 2 is started to start a test for manufacturing or research and development of an OLED.

In the first embodiment, the nitrogen is supplied to the container 1 from the pipe A, but the present invention is not limited to this, and the nitrogen may be supplied from the inlet of the nitrogen refiner 40. It may be supplied from between the desiccant dehumidifier 39 and the desiccant dehumidifier 39.

Next, an atmospheric break for performing maintenance, setup change, adjustment, etc. of the container 1 will be described. By closing the valves 18, 19, 21, 23, 31 and opening the valves 30, 32, 33, the container 1 and the nitrogen circulation line from the pipe B to the pipe D are isolated. Nitrogen is replaced with air by opening the airtightness of the container 1 and injecting dry air from the upper part of the container 1 through the pipe A. Further, the valve 32 of the pipe F is also opened so that the dry air having a low dew point supplied from the dry air supply device 37 via the pipe G is supplied from the upper part of the container 1 in one pass, whereby a large amount of air is supplied. Since air can be safely supplied at one time, the replacement speed between nitrogen and air can be significantly reduced. By supplying dry air in one pass from the upper part of the air purification filter 3 which is the easiest to hold the moisture in the container 1 without circulating the inside of the container 1, the moisture can be kept in the container even if a person works inside. Everything in 1 is discharged to the outside. The pipe F and the pipe G may be connected to directly supply the entire amount of the low dew point dry air supplied to the drying chamber 34 by operating a valve or the like from the upper part of the container 1.

By opening the valve 30 in the nitrogen circulation line, air passes through the pipe C as a circulation path, so that dry air having a high nitrogen concentration and low humidity circulates. When regenerating the catalyst in the catalyst container 5 of the nitrogen purifier 40, the valve 35 is opened to bypass the nitrogen purifier 40 and send air to the desiccant dehumidifier 39 for circulation. By operating the valve by dividing the dehumidifying device and the oxygen removing device in this way, the optimum operating environment can be prepared by changing the flow rate and the number of circulations of the gas flowing through each device. The valve is not limited to this, and an air volume adjusting device such as a damper or a VAV (Variable Air Volume) may be used.

In the first embodiment, one nitrogen purifier 40 was used, but while two or more nitrogen purifiers were installed in parallel and the catalyst of one nitrogen purifier was regenerated, another nitrogen purifier was used. The structure may be such that the nitrogen refining treatment is performed in the nitrogen purifier.

Further, a mechanism having a nitrogen refining function may be mounted inside the desiccant dehumidifier 39, and the nitrogen purifier 40 may be eliminated as an integrated device. In this case, by providing a circulation path, a bypass path, etc., the humidity and the inert gas concentration in the container 1 can be adjusted individually, and an environment with a low dew point can be created with a low active gas concentration. To. By doing so, it becomes possible to make the gas replacement system more space-saving than in the first embodiment, and it is possible to suppress the initial cost required for piping and installation work.

By covering the airtight container 1 that needs to be kept clean with a low dew point and a low active gas concentration in this way with a drying chamber 34 that supplies dry air with a low dew point, the intrusion of moisture from the outside is minimized. It becomes possible to suppress it. Further, unlike the conventional technique in which oxygen removal and moisture removal are performed by a single gas purification system as in Patent Document 1, oxygen removal is performed by a nitrogen purifier 40 and moisture removal is performed separately by a desiccant dehumidifier 39. This makes it possible to arbitrarily adjust the oxygen removal performance and the moisture removal performance, which makes it easier to optimize the equipment and manage the equipment.

As a result, the recovery time from the atmospheric environment after the atmospheric break of the container 1 to the return to a clean environment with a low dew point and a low active gas concentration can be shortened to 1/5 to 1/10 of the conventional technique. did it. In addition, it was possible to realize a gas replacement system that can easily optimize the inside of the container 1 at low humidity and low active gas concentration.

The present invention can also be used for a storage container such as a glove box used for developing a lithium ion battery material or the like, which needs to keep the storage space clean with a low dew point and a low active gas concentration.

1 Container 2 Manufacturing equipment 3 Air purification filter 4 Gas circulation path 5 Catalyst container 6 Heater 7 Pump 8 Cooler 9 Blower 10 Precooler 11 Honeycomb rotor 12 Processing zone 13 Purge zone 14 Regeneration zone 15 Cooler 16 After heater 17 Rotor drive motor 18 , 19, 21, 22, 23, 24, 25, 27, 28, 29, 30, 31, 32, 33, 35 Valve 20, 26 Flow meter 34 Drying chamber 36 Regenerating heater 37 Dry air supply device 38 Dehumidifier 39 Desicant Dehumidifier 40 Nitrogen Purifier

Claims (5)

An airtight container housed inside the drying chamber is provided, and a dry air supply device that supplies and circulates dry air having a low dew point to the drying chamber and the dry air from the dry air supply device are supplied to the drying chamber. A pipe, a pipe for returning the dry air in the drying chamber to the dry air supply device, an inert gas purification device for removing oxygen in the air to be treated in the airtight container, and a moisture content in the air to be treated. The low dew point gas supply device for removing and the pipe connected to the airtight container and connected to the airtight container have two branch paths, and one of the branch paths is in the airtight container. The route to send the air to be treated to the inert gas purification device, and the other of the branch paths is a route to send the air to be treated in the airtight container to the low dew point gas supply device, and further. The route for sending the air to be treated purified by the inert gas purification device to the low dew point gas supply device and the air to be treated leaving the low dew point gas supply device are returned to the airtight container via an air purification filter. The inert gas purification apparatus is provided with a pipe and an exhaust passage for exhausting the air in the airtight container to the outside of the drying chamber. A dry room characterized in that oxygen removal performance and moisture removal performance can be arbitrarily adjusted by separately removing moisture in the air to be treated.
A plurality of air volume adjusting devices for changing the gas flow rate and the number of circulations are provided , and at the time of an air break , a valve (23) as the air volume adjusting device provided in the middle of the pipe connected to the airtight container and having the two branch paths. ) Is closed, and the valve (31) as the air volume adjusting device provided in the middle of the pipe for returning the air to be treated from the low dew point gas supply device to the airtight container via the air purification filter is closed. The air to be treated that has left the low dew point gas supply device is branched and provided in the middle of the pipe that returns the air to be processed to the airtight container via the air purification filter, and the position of the branch is from the low dew point gas supply device. Later, it is closer to the low dew point gas supply device than the valve (31) as the air volume adjusting device, and is connected to the path for sending the processed air in the airtight container to the low dew point gas supply device. By opening the valve (30) as the air volume adjusting device provided in the middle of the pipe, a nitrogen circulation line isolated from the airtight container is formed, and the gas is formed. In the circulation line, while allowing the dry air having a high nitrogen concentration and low humidity to circulate, the supply of nitrogen to the airtight container is stopped, and the dry air supplied from the dry air supply device to the drying chamber is used. The exhaust passage having a pipe for supplying to the airtight container, opening a valve (32) as the air volume adjusting device provided in the middle of the pipe, and exhausting the air in the airtight container to the outside of the drying chamber. By opening the valve (33) as the air volume adjusting device provided in the middle of the above, the dry air is supplied from the upper part of the airtight container through the air purification filter in one pass, so that the airtight container is supplied. The dry room according to claim 1, wherein the hermetically sealed air is replaced with air . The dry room according to claim 1 or 2, wherein the air purification filter is a fan filter having a built-in HEPA filter and / or ULPA filter. The dry room according to any one of claims 1 to 3, wherein the inert gas purifier is a nitrogen purifier containing a catalyst containing copper and / or platinum as a main component. The dry room according to any one of claims 1 to 4, wherein the low dew point gas supply device is a desiccant dehumidifier.

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