JP2009074724A - Substrate heat treatment furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate heat treatment furnace capable of decomposing an organic substance included in the hot air discharged by heating treatment with high efficiency. <P>SOLUTION: The heating treatment of a glass substrate W is progressed by distributing the hot air into a furnace main body portion 10. The hot air discharged from the furnace main body portion 10 is returned to the furnace main body portion 10 through a circulation passage 20. On the way of the passage, a part of the hot air is discharged to an exhaust line 23. The exhaust line 23 is provided with a catalytic filter portion 71 constituted by retaining catalyst on a metal filter. Thus the contact efficiency of the discharged hot air and the catalyst is increased, and decomposition efficiency of the organic substance can be improved. Further the particle-shaped organic substance can be also collected, so that the decomposition efficiency of the organic substance can be totally improved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a substrate heat treatment furnace for heat-treating a glass substrate for a liquid crystal display device, a glass substrate for a plasma display panel (PDP), and a substrate for a thin plate electronic component such as a semiconductor wafer (hereinafter simply referred to as “substrate”).

  One of the manufacturing processes of a color filter is a process of baking a glass substrate on which color ink is landed by inkjet. This firing step proceeds by holding the glass substrate for a predetermined time in an air atmosphere in a firing furnace heated to a predetermined firing temperature. Moreover, when forming metal wiring on a glass substrate, a glass substrate is baked in inert gas atmosphere, such as nitrogen gas, in the same baking furnace. In any baking process, a large amount of organic substances are generated and diffused in the atmosphere by volatilization, oxidation, or thermal decomposition of the organic solvent contained in the baking object such as color ink on the glass substrate.

  For this reason, during the firing process, clean hot air is constantly blown into the firing furnace, and exhaust is continuously performed so that organic substances do not stay in the firing furnace. Since a gas containing a large amount of organic matter exhausted from the firing furnace cannot be released to the outside as it is, a process of collecting the organic matter in the exhaust with a scrubber or the like has been performed.

  On the other hand, from the viewpoint of energy saving, an attempt has been made to perform heat exchange between hot air exhausted from the firing furnace and gas newly supplied to the firing furnace. That is, if the exhaust from the firing furnace is treated with a scrubber, the amount of heat energy taken away becomes very large and the energy efficiency is poor, so the exhausted gas and the newly supplied gas are introduced into the heat exchanger, This is an attempt to recover the exhaust heat from the baking furnace by exchanging heat between them.

  If the gas exhausted from the firing furnace is introduced into the heat exchanger as it is, organic substances adhere to the structure in the heat exchanger and clogging occurs. Therefore, the exhaust gas is catalyzed to decompose the organic substances after heat treatment. It is necessary to lead to. For example, Patent Document 1 discloses a technique for guiding the exhaust gas discharged from the furnace to the heat exchanger after the catalyst treatment.

JP 2001-20271 A

  However, in the past, in order to reduce the ventilation resistance in the exhaust line, the catalyst is formed as a grid-like plate-like member, the contact efficiency between the exhaust gas and the catalyst is low, and the decomposition efficiency is lowered. It was. In particular, it has been extremely difficult to decompose a substance in which organic substances or sublimates that have passed in the form of particles are solidified. In addition, the decomposition efficiency was also lowered due to the temperature drop of the exhaust. For this reason, as a result, the decomposition efficiency of the organic matter as a whole has to be low.

  Therefore, even if the gas exhausted from the furnace for firing the glass substrate is treated with a catalyst, organic substances cannot be removed sufficiently, and as a result, the heat exchanger is clogged with deposits in a relatively short period of time, resulting in long-term continuous operation. This is not economical because the equipment utilization rate is low.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a substrate heat treatment furnace that can decompose organic substances contained in hot air discharged by heat treatment with high efficiency.

  In order to solve the above-mentioned problems, a first aspect of the present invention is a substrate heat treatment furnace for heat-treating a substrate, and a furnace body main body for accommodating the substrate therein, and at least a part of hot air discharged from the furnace body main body. And a filter that is provided in the derivation unit and carries a catalyst, and decomposes organic substances contained in the hot air led out to the derivation unit by the filter. It is characterized by doing.

  According to a second aspect of the present invention, in the substrate heat treatment furnace according to the first aspect of the present invention, the filter is a metal filter, and heating means for heating at least one of the filter and hot air introduced into the filter is provided. It is characterized by that.

  The invention according to claim 3 is the substrate heat treatment furnace according to claim 2, wherein the heating means heats at least one of the filter and hot air introduced into the filter to 200 ° C. to 400 ° C. Features.

  According to a fourth aspect of the present invention, in the substrate heat treatment furnace according to any one of the first to third aspects of the present invention, the substrate heat treatment furnace includes a casing that surrounds at least the furnace body main body, and the filter is installed outside the casing. It is characterized by.

  According to a fifth aspect of the present invention, in the substrate heat treatment furnace according to the first aspect of the present invention, a substrate enclosing at least the furnace body and the filter is provided.

  According to a sixth aspect of the present invention, in the substrate heat treatment furnace according to the first aspect of the present invention, the catalyst includes a photocatalyst.

  According to a seventh aspect of the present invention, in the substrate heat treatment furnace according to the sixth aspect of the present invention, the photocatalyst includes titanium oxide.

  The invention of claim 8 is the substrate heat treatment furnace according to the invention of claim 7, further comprising a light irradiation means for irradiating the photocatalyst with light.

  According to a ninth aspect of the invention, in the substrate heat treatment furnace according to the first aspect of the invention, the catalyst contains platinum.

  The invention of claim 10 is the substrate heat treatment furnace according to any one of claims 1 to 9, wherein the hot air discharged from the furnace body main body is circulated and supplied again to the furnace body main body. A circulation path, a circulation fan provided in the circulation path for circulating hot air, a furnace heating means provided in the circulation path for heating the hot air, and a main passage provided in the circulation path through which the hot air passes. And a filter unit, wherein the derivation unit is branched from the circulation path.

  The invention of claim 11 is the substrate heat treatment furnace according to the invention of claim 10, wherein two adsorption towers provided in parallel in the middle of the circulation path and adsorbing carbon dioxide and / or moisture, and the two Switching means for selectively switching the flow path of hot air so that hot air passes through one of the adsorption towers, and controlling the switching means so that hot air alternately passes through the two adsorption towers Switching control means.

  According to a twelfth aspect of the present invention, in the substrate heat treatment furnace according to the tenth or eleventh aspect of the present invention, the hot air outlet of the main filter portion is connected to the hot air supply port of the furnace body. .

  According to a thirteenth aspect of the present invention, in the substrate heat treatment furnace according to any one of the tenth to twelfth aspects of the present invention, the substrate heat treatment furnace further includes an outside air supply means for supplying the heated outside air to the circulation path.

  The invention of claim 14 is the substrate heat treatment furnace according to any one of claims 10 to 13, wherein 10 to 15% of the hot air is led from the circulation path to the lead-out portion, and the remaining hot air is It guide | induces to the said furnace body main-body part, It is characterized by the above-mentioned.

  The invention of claim 15 is the substrate heat treatment furnace according to any one of claims 1 to 14, wherein the substrate has a film to be fired, and the film to be fired inside the furnace main body. It is characterized by firing.

  According to a sixteenth aspect of the present invention, in the substrate heat treatment furnace according to the fifteenth aspect of the present invention, the film to be fired is a resist coating film, an organic coating film, or an inkjet coating film.

  According to the present invention, since the filter for supporting the catalyst is provided in the outlet for extracting a part of the hot air, the contact efficiency between the exhausted hot air and the catalyst is increased, and the particulate organic matter is also collected. The organic matter contained in the hot air discharged by the heat treatment can be decomposed with high efficiency.

  In particular, according to the invention of claim 2, since the heating means for heating at least one of the filter and the hot air introduced into the filter is attached, the decomposition efficiency of the organic matter by the filter can be further increased.

  In particular, according to the invention of claim 4, since the filter is installed outside the casing surrounding the furnace body main body, the maintenance of the filter is easy.

  In particular, according to the invention of claim 5, since the housing surrounding the furnace main body and the filter is provided, the filter can be heated by the heat from the furnace main body, and a special filter reheating means is provided. Is no longer necessary.

  In particular, according to the invention of claim 6, since the catalyst supported on the filter includes a photocatalyst, the organic matter remaining on the filter can be completely decomposed.

  In particular, according to the invention of claim 11, since two adsorption towers are provided in parallel in the middle of the circulation path and hot air passes through them alternately, carbon dioxide generated by the heat treatment and / or Alternatively, moisture can be removed from the hot air, and the substrate heat treatment furnace can be operated continuously for a long time.

  In particular, according to the invention of claim 14, since 10 to 15% of the hot air is led from the circulation path to the lead-out portion, the running due to the introduction of new outside air is performed while sufficiently managing the atmosphere of the hot air being circulated. An increase in cost can be suppressed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a main configuration of a substrate heat treatment furnace according to the present invention. This substrate heat treatment furnace is a hot air furnace in which a square glass substrate W on which a film to be baked such as an inkjet coating film is formed is subjected to a heat treatment to perform a baking process of the coating film. The substrate heat treatment furnace includes a furnace body main body 10 that houses a glass substrate W and performs heat treatment, a circulation path 20 that circulates hot air, an adsorption tower 30 that adsorbs moisture and carbon dioxide contained in the hot air, and a circulation fan. 40, a main heater 50, a main filter 60, a catalyst unit 70 provided in the exhaust line 23, and a heat exchanger 80. The substrate heat treatment furnace of this embodiment is provided with a control unit 90. In the configuration shown in FIG. 1, the furnace body body 10, the circulation path 20, the adsorption tower 30, butterfly dampers 31 a, 31 b, 32 a, 32 b, the circulation fan 40, the main heater 50, and the main filter 60 are provided in the casing A. The catalyst unit 70 is enclosed and installed outside the housing A.

  The furnace body 10 is a housing that can accommodate the glass substrates W in multiple stages (40 stages in the present embodiment). The inside of the furnace body 10 is a heat treatment space having a substantially quadrangular prism shape. A number of forks (not shown) are provided on the inner wall surface of the furnace body 10. Each fork is extended in the horizontal direction from the inner wall surface of the furnace body main body 10 toward the heat treatment space. A plurality of forks arranged in the horizontal direction constitute a single shelf, and 40 such shelves are formed. It is possible to place one glass substrate W in a horizontal posture on each shelf.

  A louver-type shutter 11 is provided on the front side of the furnace body 10 (left side in FIG. 1). The shutter 11 is configured by laminating a plurality of louvers in multiple stages. Each louver is provided with an elevating drive mechanism (not shown), and can be moved up and down for each louver. When the unillustrated transfer robot carries the glass substrate W in and out of the furnace body 10, the height is almost the same as the shelf so that only the part facing the loading / unloading destination shelf is used as an access opening. The position louver rises. If it does in this way, the opening at the time of carrying in / out of the glass substrate W can be made into the minimum necessary, and the leakage of the heat energy accompanying carrying in / out can be suppressed to the minimum. When driving the louver at the lower part of the shutter 11, the upper louver is also driven in conjunction with the louver. Therefore, it is necessary to provide a drive mechanism that can obtain a larger output as the lower louver. is there.

  A supply port 12 for supplying hot air to an internal heat treatment space and an exhaust port 14 for exhausting the hot air are provided on the side surface of the furnace body 10 so as to face each other. That is, the hot air supplied from one side surface of the furnace body 10 flows in the heat treatment space in the horizontal direction along the surface of the glass substrate W and flows into the opposite side surface. The supply port 12 and the exhaust port 14 are provided at a height position corresponding to the entire multistage shelf that accommodates at least the glass substrate W on the inner wall surface of the furnace body main body 10. For this reason, hot air can be uniformly supplied to the plurality of glass substrates W accommodated in the furnace body 10 to perform a uniform firing process.

  The circulation path 20 communicates the exhaust port 14 and the supply port 12 of the furnace body 10 and allows the gas supplied through the hot air discharged from the furnace body 10 to be supplied to the furnace body 10 again. It is a flow path. In the circulation path 20, an adsorption tower 30, a circulation fan 40 and a main heater 50 are interposed. In the present embodiment, an adsorption tower 30, a circulation fan 40, and a main heater 50 are provided in this order from the upstream side of the circulation path 20. The upstream side of the circulation path 20 is a side close to the exhaust port 14 of the furnace body 10, and conversely, the downstream side is a side close to the supply port 12.

  Further, an exhaust line 23 and an air supply line 26 are branched from the circulation path 20. The exhaust line 23 is a gas piping path for discharging a part of the hot air from the circulation path 20, and the air supply line 26 sucks fresh outside air (air) corresponding to the discharged hot air into the circulation path 20. It is a gas piping path for supplying. The exhaust line 23 and the air supply line 26 are branched from a portion downstream of the main heater 50 and an upstream portion of the circulation fan 40 in the circulation path 20, respectively.

In the present embodiment, the two adsorption towers 30 are provided in parallel in the middle of the circulation path 20. That is, a part of the circulation path 20 is branched into two flow paths, and the adsorption tower 30 is provided in each of the branched two flow paths. Each adsorption tower 30 is filled with an adsorbent (activated carbon in this embodiment) that adsorbs carbon dioxide (CO ₂ ) and moisture (H ₂ O). When the hot air flowing through the circulation path 20 passes through the adsorption tower 30, carbon dioxide and moisture are removed from the hot air.

  The two adsorption towers 30 and 30 are used alternatively. That is, only one of the two branched flow paths is selectively opened, and the hot air flowing through the circulation path 20 passes through only one of the two adsorption towers 30. Such channel switching is performed by the four butterfly dampers 31a, 31b, 32a, and 32b. When the butterfly dampers 31a and 31b are opened and the butterfly dampers 32a and 32b are closed, only the adsorption tower 30 on the upper side in FIG. 1 is selectively used. On the contrary, when the butterfly dampers 32a and 32b are opened and the butterfly dampers 31a and 31b are closed, only the adsorption tower 30 on the lower side in FIG. 1 is selectively used.

  The circulation fan 40 includes a motor (not shown) and swirl vanes, and the motor rotates the swirl vanes so that the circulation air flow from the upstream side to the downstream side in the circulation path 20 (that is, from the exhaust port 14). An air flow toward the supply port 12) is generated.

  The main heater 50 heats the hot air flowing through the circulation path 20 by generating heat when energized. The main filter 60 is provided at the end of the circulation path 20, that is, immediately upstream of the supply port 12 of the furnace body 10. Therefore, the hot air outlet of the main filter 60 is connected to the supply port 12 of the furnace body 10. The main filter 60 is constituted by, for example, a heat-resistant HEPA filter, passes hot air blown through the circulation path 20, and removes particles contained in the hot air to make clean hot air.

  In the present embodiment, the gas sent out by the circulation fan 40 in the circulation path 20 is heated by the main heater 50 and then purified by the main filter 60 and supplied from the supply port 12 to the heat treatment space inside the furnace body 10. The Rukoto. And the hot air discharged | emitted from the exhaust port 14 of the furnace body main-body part 10 is sent out to the downstream of the circulation path 20 by the circulation fan 40 again, after a carbon dioxide and a water | moisture content are removed by the adsorption tower 30. FIG.

  By the way, when the glass substrate W is heated, an organic solvent contained in a film to be fired (such as an ink jet coating film) on the glass substrate W is volatilized or oxidized and thermally decomposed to generate a lot of organic substances. Since an air current of hot air is constantly formed in the internal space of the furnace body 10, the organic matter released from the glass substrate W flows into the circulation path 20 from the exhaust port 14 together with the air current. In the present embodiment, when the hot air circulation system of the substrate heat treatment furnace is completely closed, firing of new organic substances is suppressed by a large amount of organic substances, or the main filter 60 is rapidly clogged and deteriorated. A new gas is supplied from the air supply line 26 to the circulation path 20, and exhaust from the circulation path 20 is performed via the exhaust line 23. In the hot air, a small amount of carbon dioxide and moisture are generated in addition to organic substances.

  The exhaust line (lead-out part) 23 is connected to the downstream side of the main heater 50 in the circulation path 20. The other end of the exhaust line 23 is connected to the heat exchanger 80 in communication. A flow rate adjusting valve 24 and a catalyst unit 70 are inserted in the middle of the exhaust line 23. The flow rate adjustment valve 24 adjusts the exhaust flow rate flowing through the exhaust line 23.

  On the other hand, the air supply line 26 is connected upstream of the circulation fan 40 in the circulation path 20 (between the adsorption tower 30 and the circulation fan 40). The other end of the air supply line 26 is also connected to the heat exchanger 80. A flow rate adjustment valve 27 is inserted in the path of the air supply line 26. The flow rate adjustment valve 27 adjusts the exhaust flow rate flowing through the air supply line 26.

  The heat exchanger 80 is a device that performs heat exchange between gas and gas. For example, a heat storage type heat exchanger that performs heat exchange by alternately passing air supply and exhaust through a rotating heat storage body is used. Can do. The heat exchanger 80 of this embodiment performs heat recovery by transferring heat from the hot exhaust gas flowing through the exhaust line 23 to a new gas sucked by the air supply line 26. Alternatively, the heat exchanger 80 may be a low pressure loss device such as a multistage plate heat exchanger in which gas flows alternately.

The catalyst unit 70 includes a catalyst filter unit 71, a reheat heater 72, and a light source 73. The catalyst filter unit 71 has platinum (Pt) or platinum rhodium (Pt—Rh) particles functioning as a catalyst supported on a metal filter formed of a metal mesh (in this embodiment, a stainless steel mesh). Is. In the present embodiment, titanium oxide (TiO ₂ ) that functions as a photocatalyst is mixed in a part of the supported catalyst. The catalyst filter unit 71 has a function as a catalyst for decomposing organic substances contained in the hot exhaust gas and a function as a filter for removing particles. An intermediate layer of alumina (Al ₂ O ₃ ) or chromium oxide (Cr ₂ O ₃ ) may be formed between the metal filter and the catalyst layer. By providing such a ceramic intermediate layer, the durability and heat resistance of stainless steel can be improved, and the life of the metal filter can be extended.

  The reheat heater 72 is a heat source that heats the hot exhaust gas that passes through the catalyst unit 70 by generating heat when energized. In the catalyst unit 70, the reheat heater 72 and the catalyst filter portion 71 are continuously arranged in this order from the upstream side of the exhaust line 23. Therefore, the hot exhaust gas heated by the reheat heater 72 immediately flows into the catalyst filter unit 71. The light source 73 irradiates the catalyst filter unit 71 with light. The photocatalyst carried on the catalyst filter portion 71 exhibits a catalytic action when it receives light from the light source 73.

  The hardware configuration of the controller 90 provided in the substrate heat treatment furnace is the same as that of a general computer. That is, the control unit 90 stores a CPU that performs various arithmetic processes, a ROM that is a read-only memory that stores basic programs, a RAM that is a readable and writable memory that stores various information, and control applications and data. It is equipped with a magnetic disk. The control unit 90 is electrically connected to each of the four butterfly dampers 31a, 31b, 32a, and 32b, and controls their operations. The control unit 90 operates the entire operation mechanisms of the substrate baking furnace (such as the circulation fan 40, the main heater 50, the reheating heater 72, the light source 73, the flow rate adjusting valves 24 and 27, and the raising / lowering drive mechanism of the shutter 11). Also controls.

  Next, the operation content in the substrate heat treatment furnace having the above configuration will be described. First, during the heat treatment, a transfer robot (not shown) sequentially carries the glass substrates W into the furnace body 10 at regular intervals and passes them to a predetermined level shelf. The glass substrate W placed on the fork constituting the shelf is heated to the firing temperature by hot air from the supply port 12. And the glass substrate W which predetermined baking time passed in the furnace body main-body part 10 is carried out by the said conveyance robot.

  In the present embodiment, the square glass substrate W on which a film to be fired such as an inkjet coating film is formed is heat-treated, and the film to be fired is fired. The film to be baked is not limited to an inkjet coating film, and may be a resist coating film or an organic coating film. Regardless of the film to be fired, the organic solvent contained in the film to be fired on the glass substrate W volatilizes or oxidizes, so that many organic substances are generated and diffused into the atmosphere in the furnace body 10. In addition, a slight amount of moisture and carbon dioxide is generated by the firing treatment. And the hot atmosphere containing organic substance etc. is discharged | emitted from the exhaust port 14 of the furnace main body part 10 as a hot air. The hot air discharged from the exhaust port 14 is circulated in the circulation path 20 by the circulation fan 40, heated by the main heater 50, and then supplied again from the supply port 12 to the inside of the furnace body main body 10 through the main filter 60. The

  Particles contained in the hot air circulating in the circulation path 20 are captured by the main filter 60. Further, two adsorption towers 30 are provided in parallel in the circulation path 20, and the flow path of the hot air is divided into four butterfly dampers 31 a, 31 a, so that only one of them passes. It is switched alternatively by 31b, 32a, 32b. The adsorption tower 30 adsorbs and removes moisture and carbon dioxide contained in the hot air generated during firing. Particles and the like are removed by the main filter 60, and moisture and carbon dioxide are removed by the adsorption tower 30, so that the hot air circulating in the circulation path 20 can be cleaned, and the interior of the furnace body 10 In addition, an atmosphere suitable for the baking treatment can be stably formed.

  In the adsorption tower 30 through which the hot air passes, the adsorption ability of the activated carbon gradually decreases, so that moisture and carbon dioxide cannot be sufficiently removed by adsorption. For this reason, the adsorption tower 30 to be used is switched at an appropriate timing. That is, the controller 90 controls the opening and closing of the four butterfly dampers 31a, 31b, 32a, and 32b so that the hot air alternately passes through the two adsorption towers 30. The timing of switching the adsorption tower 30 to be used may be switched when the operation time of the adsorption tower 30 has passed a predetermined time, and the concentration of water vapor or carbon dioxide contained in the hot air is a predetermined value. You may make it switch at the time of exceeding.

  After the adsorption tower 30 to be used is switched, the regeneration process of the adsorption tower 30 used so far is performed. As the regeneration treatment, for example, a regeneration heater may be provided in the adsorption tower 30 so that the activated carbon is heated so that the adsorbed water and carbon dioxide are released to recover the adsorption ability. The temperature control of the heater at this time may be automatically performed by the control unit 90. Moreover, as a regeneration process, the activated carbon of the adsorption tower 30 may be simply replaced with a new one. Note that the heater, the necessary air circulation means, the fan, and the regeneration channel are not shown.

  Eventually, the four butterfly dampers 31a, 31b, 32a, and 32b are switched again so that the hot air passes through the adsorption tower 30 that has completed the regeneration process and has recovered the adsorption ability. Then, the reprocessing of the other adsorption tower 30 is performed in the same manner. If it does in this way, it will become possible to operate continuously, without stopping a substrate heat treatment furnace.

  A part of the hot air circulated in the circulation path 20 flows into the exhaust line 23 and is discharged outside. In the present embodiment, 10 to 15% of the hot air circulating through the circulation path 20 is guided to the exhaust line 23 by the control unit 90 adjusting the flow rate adjusting valves 24 and 27, and the remainder is the furnace body main unit 10. Led to. If the hot air discharged from the exhaust line 23 is less than 10%, the main filter 60 and the adsorption tower 30 alone cannot sufficiently manage the atmosphere of the hot air circulated in the circulation path 20, and exceeds 15%. And the running cost accompanying the introduction of new outside air from the air supply line 26 increases.

  The hot air flowing into the exhaust line 23 is reheated by the reheat heater 72. In the present embodiment, the reheating heater 72 reheats the hot air led out to the exhaust line 23 to 200 ° C. to 400 ° C. Then, the reheated hot air passes through the catalyst filter unit 71. Here, instead of heating the hot air or in addition to heating the hot air, the catalyst filter unit 71 may be heated to 200 ° C. to 400 ° C. In this case, the catalyst filter unit 71 may be heated by induction heating, lamp heating, resistance heating, or the like.

  When the hot air led out to the exhaust line 23 passes through the catalyst filter unit 71, the thermal decomposition and the oxidative decomposition of the organic matter contained in the hot air are simultaneously generated. Specifically, the organic matter is oxidized and decomposed into water and carbon dioxide. In this embodiment, since the catalyst is supported on a metal filter composed of a metal mesh, the contact efficiency between the exhausted hot air and the catalyst is increased, and the decomposition efficiency of the organic matter is increased. Can do. Even if the hot air contains a solidified organic substance or a sublimated substance that passes through in the form of particles, the catalyst filter unit 71 is constituted by a metal filter. 71 will be collected.

  Further, since the hot air reheated to 200 ° C. to 400 ° C. by the reheat heater 72 flows into the catalyst filter portion 71, the catalyst temperature of the catalyst filter portion 71 also becomes high, and the organic matter contained in the hot air is highly efficient. Will be disassembled. That is, by continuously arranging the reheat heater 72 and the catalyst filter unit 71 from the upstream side, the temperature drop of the hot air from the reheat heater 72 to the catalyst filter unit 71 is suppressed to the minimum, and the catalyst filter unit 71. The maximum efficiency of decomposition is achieved.

  The hot air from which the organic substances have been removed through the catalyst filter unit 71 flows into the heat exchanger 80. On the other hand, new gas is supplied from the air supply line 26 in order to compensate for the hot air discharged through the exhaust line 23. This newly supplied gas also passes through the heat exchanger 80. In the heat exchanger 80, heat exchange is performed between the hot air discharged from the exhaust line 23 and the gas newly supplied via the air supply line 26. Thereby, while the temperature of exhaust gas falls, supply gas is heated and the temperature rises. At this time, since most of the organic matter contained in the hot air discharged from the exhaust line 23 is decomposed, the adhesion of the organic matter to the structure in the heat exchanger 80 is very small, and the heat exchanger 80 is clogged. And the heat exchanger 80 can be stably operated for a long period of time.

  Exhaust gas whose temperature has decreased after passing through the heat exchanger 80 is discharged to an external exhaust heat duct or the like. Of course, organic matter is hardly contained in the exhaust airflow. On the other hand, the supply gas whose temperature has increased through the heat exchanger 80 passes through the flow rate adjustment valve 27 and flows into the circulation path 20. Since the newly supplied gas flows into the upstream side of the main heater 50, there is no possibility of lowering the temperature of the hot air supplied to the furnace body 10, and the furnace is heated from the supply port 12 after being heated by the main heater 50. It will be supplied into the body main body 10. Thus, if the heat exchanger 80 can be used to perform heat exchange between the supply gas and the exhaust gas, the energy efficiency in the substrate heat treatment furnace can be increased.

  As described above, in the present embodiment, since the catalyst filter portion 71 having the catalyst supported on the metal filter is provided in the exhaust line 23, the contact efficiency between the hot air exhausted and the catalyst is higher than in the prior art. The decomposition efficiency of organic matter can be increased. Moreover, it becomes possible to collect particulate organic substances, and the decomposition efficiency of the organic substances as a whole can be increased. Furthermore, since the hot air flowing into the catalyst filter unit 71 is reheated to 200 ° C. to 400 ° C. by the reheat heater 72, the decomposition efficiency of the organic matter is further increased, and the organic matter contained in the hot air discharged from the exhaust line 23 Can be reliably disassembled. Further, since the catalyst unit 70 is installed outside the housing A, maintenance of the catalyst unit 70 including the catalyst filter portion 71 is facilitated.

  Further, the catalyst unit 70 of the present embodiment includes a light source 73, and a photocatalyst is included in a part of the catalyst carried on the catalyst filter unit 71. When light is emitted from the light source 73 to the catalyst filter unit 71 at an appropriate timing, the photocatalyst of the catalyst filter unit 71 receives light to show a catalytic action, and the organic matter partially remaining on the metal filter is efficiently removed. It can be decomposed well. That is, a kind of cleaning process can be executed by irradiating the catalyst filter unit 71 with light from the light source 73. Note that, without providing the light source 73, catalytic action may be generated in the catalyst filter unit 71 using light from an indoor lighting fixture or the like.

  While the embodiments of the present invention have been described above, the present invention can be modified in various ways other than those described above without departing from the spirit of the present invention. For example, in the above embodiment, the heat exchanger 80 is provided to perform heat exchange between the heat exhaust and newly supplied outside air. However, the catalyst unit is connected to the exhaust line not provided with the heat exchanger 80. 70 may be provided. Even if it does in this way, the organic substance contained in the hot air discharged | emitted by heat processing can be decomposed | disassembled with high efficiency. In short, if a metal filter supporting a catalyst is arranged in a lead-out part that leads at least a part of the hot air discharged from the furnace body 10 to a part having a temperature lower than that of the hot air, organic substances contained in the discharged hot air Can be decomposed with high efficiency.

  Further, all of the catalyst supported on the catalyst filter unit 71 may be a photocatalyst. In this case, when hot air is discharged from the exhaust line 23, light is emitted from the light source 73 to the catalyst filter unit 71.

  Further, the catalyst may be supported on a sintered ceramic filter instead of the metal filter of the catalyst filter portion 71.

  In the above embodiment, activated carbon is used as the adsorbent for the adsorption tower 30. However, the present invention is not limited to this, and any material that adsorbs carbon dioxide and / or moisture may be used. Zeolite may be used.

  The heat exchanger 80 is not limited to a heat storage type heat exchanger, and may be a plate type heat exchanger having a flow path through which air supply and exhaust alternately pass.

  Further, the number of glass substrates W that can be accommodated in the furnace body 10 of the substrate baking furnace is not limited to 40, and may be any number.

  In addition, as shown in FIG. 2, the catalyst unit 70 may be surrounded by a common casing B together with the furnace body 10, the adsorption tower 30, the circulation fan 40, the main heater 50, and the main filter 60. In this way, the catalyst filter portion 71 can be heated by the heat from the furnace body main body portion 10, so that the reheat heater 72 is not necessary. The remaining configuration in FIG. 2 is the same as that in FIG.

  Further, the substrate to be baked by the substrate heat treatment furnace according to the present invention is not limited to the glass substrate W, and may be a semiconductor wafer.

It is a figure which shows the principal part structure of the substrate heat processing furnace which concerns on this invention. It is a figure which shows the other example of the principal part structure of a substrate heat processing furnace.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Furnace main-body part 20 Circulation path | route 23 Exhaust line 24,27 Flow control valve 26 Supply line 30 Adsorption tower 31a, 31b, 32a, 32b Butterfly damper 40 Circulation fan 50 Main heater 60 Main filter 70 Catalyst unit 71 Catalyst filter part 72 Reheat heater 73 Light source 80 Heat exchanger 90 Control unit

Claims (16)

A substrate heat treatment furnace for heat-treating a substrate,
A furnace body body for accommodating the substrate therein;
A deriving unit for deriving at least part of the hot air discharged from the furnace body main body to a portion having a temperature lower than that of the hot air;
A filter provided in the lead-out portion and carrying a catalyst;
With
An organic substance contained in the hot air led to the lead-out part is decomposed by the filter. In the substrate heat treatment furnace according to claim 1,
The filter is a metal filter;
A substrate heat treatment furnace comprising heating means for heating at least one of the filter and hot air introduced into the filter. The substrate heat treatment furnace according to claim 2,
The substrate heat treatment furnace characterized in that the heating means heats at least one of the filter and hot air introduced into the filter to 200 ° C. to 400 ° C. In the substrate heat treatment furnace according to any one of claims 1 to 3,
A substrate heat treatment furnace comprising: a housing surrounding at least the furnace body main body, wherein the filter is installed outside the housing. In the substrate heat treatment furnace according to claim 1,
A substrate heat treatment furnace comprising a housing surrounding at least the furnace body and the filter. In the substrate heat treatment furnace according to claim 1,
The substrate heat treatment furnace, wherein the catalyst includes a photocatalyst. In the substrate heat treatment furnace according to claim 6,
The substrate heat treatment furnace, wherein the photocatalyst contains titanium oxide. The substrate heat treatment furnace according to claim 7,
A substrate heat treatment furnace, further comprising light irradiation means for irradiating the photocatalyst with light. In the substrate heat treatment furnace according to claim 1,
The substrate heat treatment furnace, wherein the catalyst contains platinum. In the substrate heat treatment furnace according to any one of claims 1 to 9,
A circulation path for circulating hot air discharged from the furnace body main body and supplying the hot air to the furnace body main body again;
A circulation fan provided in the circulation path for circulating hot air;
A heating means for a furnace body provided in the circulation path for heating hot air;
A main filter part that is provided in the circulation path and allows hot air to pass through;
With
The substrate heat treatment furnace, wherein the lead-out portion is branched from the circulation path. In the substrate heat treatment furnace according to claim 10,
Two adsorption towers provided in parallel in the middle of the circulation path and adsorbing carbon dioxide and / or moisture;
Switching means for selectively switching the flow path of the hot air so that the hot air passes through one of the two adsorption towers;
Switching control means for controlling the switching means so that hot air alternately passes through the two adsorption towers;
A substrate heat treatment furnace comprising: In the substrate heat treatment furnace according to claim 10 or 11,
A substrate heat treatment furnace characterized in that a hot air outlet of the main filter part is connected to a hot air supply port of the furnace body part. In the substrate heat treatment furnace according to any one of claims 10 to 12,
A substrate heat treatment furnace, further comprising outside air supply means for supplying heated outside air to the circulation path. In the substrate heat treatment furnace according to any one of claims 10 to 13,
A substrate heat treatment furnace characterized in that 10 to 15% of hot air is led from the circulation path to the lead-out part, and the remaining hot air is led to the furnace body main part. In the substrate heat treatment furnace according to any one of claims 1 to 14,
The substrate has a film to be fired;
A substrate heat treatment furnace characterized in that the film to be fired is fired inside the furnace body. The substrate heat treatment furnace according to claim 15,
The substrate heat treatment furnace, wherein the fired film is a resist coating film, an organic coating film, or an inkjet coating film.

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