JP2010144939A - Circulation type substrate burning furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a circulation type substrate burning furnace capable of reducing a heat loss and obtaining a stable burning temperature. <P>SOLUTION: By blowing out hot air to the inside of a furnace body 10, the burning processing of a glass substrate W is made to progress. The hot air discharged from the furnace body 10 is circulated within a circulation route 20 by a circulation fan 40 is passed through an adsorption tower 30 for adsorbing a decomposition product from a catalyst filter 70 for decomposing organic matters, and reheated by a main heater 52. Since hot air discharged from the furnace body 10 is made to flow into the catalyst filter 70 without a change to decompose the organic matters included in the hot air, an additional heater for heating a catalyst is not required so as to reduce the heat loss. Since a burning temperature in the furnace body 10 can be adjusted only by control by the main heater 52, temperature control can be easily performed so as to obtain the stable burning temperature. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention performs a firing process on a glass substrate for a liquid crystal display device, a glass substrate for a PDP (plasma display panel) or a substrate for a thin plate electronic component such as a semiconductor wafer (hereinafter simply referred to as “substrate”) while circulating hot air. The present invention relates to a circulating substrate baking furnace.

  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 of the baking treatment steps, a large amount of organic substances are generated and diffused in the atmosphere by volatilization or oxidation 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.

  However, if the heat exhaust from the firing furnace is processed with a scrubber, the amount of heat energy taken away becomes very large and the energy efficiency is poor, so that the heat energy that is exhausted by using the exhausted hot air once is recycled as much as possible. Less circulating kilns are also used. In the circulation-type firing furnace, a part of the heat exhaust of the firing furnace is exhausted to the outside, and a corresponding amount of fresh outside air is introduced.

  Even in a circulation type firing furnace, a catalyst is provided in the exhaust line or the circulation line to decompose and remove organic substances. In order to fully decompose organic matter, the catalyst temperature needs to be higher than the specified temperature. Especially when a catalyst is provided in the exhaust line, the exhaust temperature decreases greatly, so a separate heater is required to heat the catalyst. It was an element of. For example, Patent Document 1 discloses a technique for controlling a heater temperature by providing a heater and a catalyst in an exhaust line and detecting an outlet side temperature of the catalyst.

JP 2005-338840 A

  However, adding a heater only for heating the catalyst to the exhaust line for discharging to the outside results in a large heat loss and a high cost factor. Further, even when a catalyst is provided in the circulation line, providing an additional heater not only causes an increase in cost but also makes it difficult to control the firing temperature. That is, temperature control is required for each of the main heater and the auxiliary heater for the catalyst for circulation to the firing furnace, and both of these heaters are provided in the circulation line, so that the temperature becomes a disturbance factor with each other. The fluctuation of becomes large. As a result, the stability of the firing temperature of the firing furnace is impaired, causing a problem in the reproducibility of the firing process.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a circulation type substrate firing furnace that has a small heat loss and can obtain a stable firing temperature.

  In order to solve the above-mentioned problem, the invention of claim 1 is a circulation type substrate baking furnace for circulating a hot air to perform a substrate baking process, and a furnace body main body for accommodating a substrate therein, and the furnace body main body. A circulation path that circulates the hot air discharged from the furnace and supplies it again to the furnace body main body, a circulation fan that is provided in the circulation path and circulates the hot air, and a main heater that heats the hot air circulated through the circulation path And a catalyst filter section having a metal filter that is provided in the circulation path and carries a catalyst, and a trap means that is provided in the circulation path and traps carbon dioxide and / or moisture.

  Further, the invention of claim 2 is the circulation type substrate baking furnace according to the invention of claim 1, wherein the trap means is bifurcated in the middle of the circulation path and is divided into two flow paths that merge again. A switching unit that includes two trap towers provided in parallel, and that selectively switches the two flow paths so that hot air passes through one of the two trap towers; And a switching control unit that controls switching timing.

  The invention according to claim 3 is the circulating substrate baking furnace according to claim 2, wherein the two trap towers are two adsorption towers that adsorb carbon dioxide and / or moisture. To do.

  According to a fourth aspect of the present invention, in the circulation type substrate firing furnace according to the second aspect of the present invention, the two trap towers are two absorption towers that absorb carbon dioxide.

  The invention according to claim 5 is the circulation type substrate firing furnace according to claim 4, wherein each of the two absorption towers releases a carbon dioxide absorbent and the absorbed carbon dioxide from the absorbent. And a recovery system for recovering carbon dioxide released from the absorbent material.

  Further, the invention of claim 6 is the circulation type substrate firing furnace according to any one of claims 1 to 5, wherein the catalyst filter portion is downstream of the furnace body main body portion in the circulation path. It is provided between the side and the trap means.

  The invention according to claim 7 is the circulation type substrate firing furnace according to any one of claims 1 to 5, wherein the catalyst filter portion is located downstream of the main heater in the circulation path. It is provided between the main body part and the furnace body.

  The invention according to claim 8 is the circulation type substrate firing furnace according to any one of claims 2 to 5, wherein the catalyst filter section is provided in each of the two flow paths. And

  The invention according to claim 9 is the circulating substrate baking furnace according to any one of claims 1 to 8, wherein the catalyst includes a photocatalyst, and the catalyst filter unit irradiates the photocatalyst with light. It is characterized by comprising light irradiating means.

  The invention according to claim 10 is the circulation type substrate firing furnace according to any one of claims 1 to 9, wherein the hot air inlet of the furnace body is provided with a metal filter. .

  According to the present invention, the hot air discharged from the furnace main body flows into the catalyst filter part in the process of being circulated through the circulation path, and the organic matter contained in the hot air is decomposed. No heater is required and heat loss can be reduced. Further, since the firing temperature inside the furnace body main body can be adjusted by controlling only the main heater, temperature control becomes easy and a stable firing temperature can be obtained.

  In particular, according to the invention of claim 2, in order to selectively switch one of the trap towers through which the hot air passes, one of the trap towers is regenerated while the other trap tower is being used. This can be performed, and a reduction in the operating rate of the substrate baking furnace accompanying maintenance can be suppressed.

  In particular, according to the invention of claim 6, since the catalyst filter part is provided in the circulation path downstream from the furnace body main part and to the trap means, the catalyst body is discharged from the furnace body. The hot air thus made flows directly into the catalyst filter part, and the organic matter contained in the hot air can be decomposed with high efficiency.

  In particular, according to the invention of claim 7, since the catalyst filter portion is provided in the circulation path downstream from the main heater and reaching the furnace body main body, it is heated by the main heater. Immediately after the hot air flows into the catalyst filter part, the organic matter contained in the hot air can be decomposed with high efficiency.

  In particular, according to the invention of claim 8, since the catalyst filter section is provided in each of the two flow paths, the catalyst filter section to be used is switched at the same time as the trap tower is switched. The catalyst filter unit can be maintained together with the regeneration process, and it is not necessary to stop the substrate baking furnace for the maintenance of the catalyst filter unit, so that the operating rate of the substrate baking furnace can be improved.

  In particular, according to the invention of claim 9, since the catalyst supported on the metal filter contains a photocatalyst, the organic matter remaining on the metal filter can be completely decomposed.

  In particular, according to the invention of claim 10, since the hot air inlet of the furnace body main body is provided with the metal filter, the organic matter remaining without being completely decomposed by the catalyst filter section is removed, and the furnace body main body portion is removed. The cleanliness of the hot air introduced into can be further improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this specification, the term “trap” is a conceptual term including both “adsorption” in which a decomposition product such as carbon dioxide is physically sucked and taken in and “absorption” in which the decomposition product is taken in by a chemical reaction. It is.

<1. First Embodiment>
FIG. 1 is a diagram showing an overall configuration of a first embodiment of a circulation type substrate firing furnace according to the present invention. This substrate baking furnace performs a baking process on a square glass substrate W on which color ink for a color filter or the like is placed while circulating hot air, and a furnace body that stores the glass substrate W and performs a baking process Part 10, circulation path 20 for circulating hot air, catalyst filter part 70 having a catalyst for decomposing organic matter supported on a filter, adsorption tower 30 for adsorbing moisture and carbon dioxide contained in the hot air, and circulation fan 40 And a main heater 52 that heats the hot air, and a metal filter 54. In addition, a controller 90 is provided in the substrate baking furnace.

  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 into and out of the furnace body 10, the height is substantially the same as the shelf so that only the part facing the carry-in / out 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 hot air inlet 12 for introducing hot air into an internal heat treatment space and a hot air exhaust port 14 for exhausting hot air are provided on the side surfaces 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 hot air introduction port 12 and the hot air 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 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 hot air exhaust port 14 and the hot air introduction port 12 of the furnace body 10, circulates the hot air discharged from the furnace body 10, and supplies gas to the furnace body 10 again. This is a possible flow path. In the middle of the circulation path 20, a catalyst filter unit 70, an adsorption tower 30, a circulation fan 40 and a main heater 52 are interposed. In the first embodiment, a catalyst filter unit 70 is provided between the circulation path 20 and the downstream side of the furnace body 10 and to the adsorption tower 30. The upstream side of the circulation path 20 is a side close to the hot air exhaust port 14 of the furnace body 10, and the downstream side is a side close to the hot air inlet 12.

  The catalyst filter unit 70 is platinum (Pt) or platinum rhodium (Pt-Rh) that functions as a catalyst in a metal filter composed of a metal mesh excellent in heat resistance (a stainless steel mesh in the first embodiment). The catalyst filter 71 carrying the particles is provided. The catalyst filter unit 70 has a function as a catalyst for decomposing organic substances contained in hot air and a function as a filter for removing particles.

The two adsorption towers 30, 30 are provided in parallel in the circulation path 20. That is, the circulation path 20 is branched into two flow paths 20a and 20b in a part of the path, and the adsorption tower 30 is provided in each of the branched flow paths 20a and 20b. The two flow paths 20a and 20b branched in two are merged again. Each adsorption tower 30 is filled with an adsorbent (activated carbon in the first 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.

  Each of the two adsorption towers 30 is provided with a bypass line 34 for collecting carbon dioxide and moisture, and with a regeneration heater 33 for releasing the adsorbed carbon dioxide and moisture from the adsorbent. Yes. When the adsorbent that adsorbs carbon dioxide and moisture is heated by the regeneration heater 33, the adsorbed carbon dioxide and moisture are released from the adsorbent. The bypass line 34 collects carbon dioxide and moisture released from the adsorbent by applying a pressure difference in the opposite direction to the flow paths 20 a and 20 b of the circulation path 20 to the adsorption tower 30.

  The two adsorption towers 30 and 30 are used alternatively. Specifically, only one of the two branched flow paths 20a and 20b is selectively opened, and the hot air flowing through the circulation path 20 passes through only one of the two adsorption towers 30. Will be. 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, the flow path 20a is opened and only the adsorption tower 30 on the left side of 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, the flow path 20b is opened and only the adsorption tower 30 on the right side of FIG. 1 is selectively used. . That is, the butterfly dampers 31a, 31b, 32a, 32b serve as switching means for selectively switching the hot air flow paths 20a, 20b so that the hot air passes through one of the two adsorption towers 30, 30. Function.

  The circulation fan 40 includes a motor and swirl vanes (not shown), and the motor rotates the swirl vanes so that hot air circulates in the circulation path 20 from the upstream side to the downstream side (that is, hot air exhaust). An air flow from the mouth 14 toward the hot air inlet 12 is generated. The main heater 52 is a heat source that heats hot air circulated through the circulation path 20 by generating heat when energized.

  The metal filter 54 is attached to the hot air inlet 12 of the furnace body 10. That is, the metal filter 54 is provided at the end of the circulation path 20, and the hot air outlet of the metal filter 54 is directly connected to the hot air inlet 12 of the furnace body 10. The metal filter 54 removes particles contained in the hot air to make clean hot air.

  The hardware configuration of the controller 90 provided in the substrate baking 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 also controls the operation of each operation mechanism (circulation fan 40, main heater 52, raising / lowering drive mechanism of the shutter 11, etc.) of the entire substrate baking furnace.

  Next, the operation content in the circulation type substrate firing furnace having the above configuration will be described. First, during the firing process, the transfer robot sequentially carries the glass substrates W into the furnace body main 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 the hot air from the hot air inlet 12. And the glass substrate W which predetermined baking time passed in the furnace body main-body part 10 is carried out by the conveyance robot.

  When the object to be fired placed on the glass substrate W is a color ink as in the present embodiment, heated air is circulated and the furnace body 10 is made into an air atmosphere, but the object to be fired is a metal wiring material. In the case of (organic metal), an inert gas atmosphere such as nitrogen gas is used (that is, the heated inert gas is circulated). Regardless of the material to be fired, the organic solvent contained in the material to be fired on the glass substrate W is volatilized or oxidized by the firing treatment, so that many organic materials are generated in the atmosphere in the furnace body 10. Dissipate. The hot atmosphere containing the organic matter is discharged as hot exhaust (hot air) from the hot air exhaust port 14 of the furnace body 10.

  The hot exhaust discharged from the hot air exhaust port 14 is circulated in the circulation path 20 by the circulation fan 40. In this circulation process, the hot air discharged from the hot air exhaust port 14 is first fed to the catalyst filter unit 70. As the discharged hot air passes through the catalyst filter unit 71, a decomposition reaction of organic substances contained in the hot air occurs. Specifically, the organic matter is decomposed into water and carbon dioxide. In the first embodiment, since the hot air passes through the catalyst filter 71 in which catalyst particles are supported on a metal filter constituted by a metal mesh, the contact efficiency between the exhausted hot air and the catalyst is high. It becomes high and the decomposition efficiency of organic substance can be made high. Further, even if the hot air contains substances obtained by solidifying organic substances or sublimates passing through in the particle state, these substances are collected by the catalyst filter 71.

  When the object to be baked is color ink as in the first embodiment, heated air is circulated as hot air, and the catalytic filter unit 70 undergoes thermal decomposition and oxidative decomposition of organic substances simultaneously. For this reason, the temperature of the catalyst filter 71 is further increased by the heat generated by the oxidative decomposition, and the decomposition efficiency of the organic matter can be further increased. In addition, when the object to be fired is a metal wiring material, an inert gas (nitrogen gas) heated as hot air is circulated, so that only the organic substance is thermally decomposed in the catalyst filter unit 70. Even when the firing process is performed in an inert gas atmosphere, an oxidizing atmosphere supply mechanism for supplementarily supplying oxygen (or air) to the catalyst filter unit 70 is provided, and the organic matter is thermally decomposed by the catalyst filter 71. And oxidative decomposition may be generated to increase the decomposition efficiency of organic matter.

  As described above, the organic matter is decomposed into water and carbon dioxide in the catalyst filter unit 70. These decomposition products generated by the decomposition are included in the hot air as a gas phase. If these concentrations in the hot air become too high, the firing process may be hindered. For this reason, the two adsorption towers 30 and 30 are provided in the middle of the circulation path 20 in the circulation type substrate baking furnace of the first embodiment. The adsorption tower 30 is filled with activated carbon, and moisture and carbon dioxide as decomposition products are adsorbed and removed by the passage of hot air. Thereby, the density | concentration of the water vapor | steam and carbon dioxide in a hot air does not become higher than necessary, and a board | substrate baking furnace can be operated stably for a long period of time.

  The two adsorption towers 30, 30 are provided in parallel in the middle of the circulation path 20, and the hot air flow paths 20a, 20b include four butterfly dampers 31a so that only one of them passes through. , 31b, 32a, and 32b. Therefore, the hot air that has decomposed the organic matter through the catalyst filter unit 70 flows into one of the two adsorption towers 30 and 30 and is subjected to moisture and carbon dioxide removal processing.

  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 control unit 90 controls the switching timing 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, or the concentration of water vapor or carbon dioxide contained in the hot air has a predetermined value. You may make it switch at the time of exceeding.

  After switching of the adsorption tower 30 to be used, the regeneration process of the adsorption tower 30 used so far is performed. In the regeneration process, the adsorbent is heated by the regeneration heater 33 to separate the adsorbed moisture and carbon dioxide, and the bypass line 34 applies a pressure difference in the opposite direction to the circulation line 20 to the adsorption tower 30 to remove the separated moisture and The adsorption ability may be recovered by recovering carbon dioxide. The temperature control of the regeneration heater 33 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.

  Eventually, the four butterfly dampers 31a, 31b, 32a, and 32b are switched again by the control unit 90 so that the hot air passes through the adsorption tower 30 in which the regeneration process is completed and the adsorption capacity is recovered. And the regeneration process of the other adsorption tower 30 is performed similarly. If the two adsorption towers 30 and 30 are alternately used in this manner, the substrate baking furnace can be operated continuously without stopping.

  The hot air from which moisture and carbon dioxide have been removed in the adsorption tower 30 is sent to the main heater 52 by the circulation fan 40 and reheated. The hot air heated by the main heater 52 is sent to the metal filter 54. In the metal filter 54, the organic matter remaining without being completely decomposed by the catalyst filter unit 70 is also removed, and the cleanliness of the hot air can be further improved. The hot air that has passed through the metal filter 54 is supplied again from the hot air inlet 12 into the furnace body 10.

  In the substrate firing furnace of the first embodiment, the hot air discharged from the furnace body main body 10 flows into the catalyst filter unit 70 as it is, and the organic matter contained in the hot air is decomposed. Therefore, a separate heater for heating the catalyst becomes unnecessary, and heat loss can be reduced. Further, since the firing temperature inside the furnace body 10 can be adjusted by controlling only the main heater 52, temperature control is facilitated and a stable firing temperature can be obtained.

<2. Second Embodiment>
Next, a second embodiment of the present invention will be described. FIG. 2 is a diagram illustrating an overall configuration of a circulation type substrate firing furnace according to the second embodiment. In FIG. 2, the same elements as those in the first embodiment are denoted by the same reference numerals. The substrate baking furnace of the second embodiment is different from the first embodiment in that the catalyst filter unit 70 includes a light source 72 in addition to the catalyst filter 71.

In the second embodiment, titanium oxide (TiO ₂ ) that functions as a photocatalyst is mixed in a part of the catalyst carried by the catalyst filter 71. The light source 72 included in the catalyst filter unit 70 irradiates the catalyst filter 71 with light. The photocatalyst carried on the catalyst filter 71 exhibits catalytic action by receiving light from the light source 72. The remaining configuration of the substrate baking furnace of the second embodiment is the same as that of the first embodiment.

  The operation content in the substrate baking furnace of the second embodiment is also substantially the same as that of the first embodiment, and similarly to the first embodiment, heat loss can be suppressed to a low level and a stable baking temperature can be obtained. In the second embodiment, light is emitted from the light source 72 to the catalyst filter 71 at an appropriate timing. If it does in this way, the photocatalyst of the catalyst filter 71 will receive a light, will show a catalytic action, and the organic substance which remained partly on the metal filter can be decomposed | disassembled efficiently. That is, a kind of cleaning process can be performed by irradiating the catalyst filter 71 with light from the light source 72.

<3. Third Embodiment>
Next, a third embodiment of the present invention will be described. FIG. 3 is a diagram illustrating an overall configuration of a circulation type substrate firing furnace according to the third embodiment. In FIG. 3, the same elements as those in the first embodiment are denoted by the same reference numerals. The difference between the circulating substrate baking furnace of the third embodiment and the first embodiment is the arrangement position of the catalyst filter unit 70.

  As shown in FIG. 3, in the third embodiment, a catalyst filter unit 70 is provided in the circulation path 20 downstream from the main heater 52 and reaching the furnace body 10. The remaining configuration of the substrate baking furnace of the second embodiment is the same as that of the first embodiment.

  In the third embodiment, hot air discharged from the hot air exhaust port 14 of the furnace body 10 and circulated in the circulation path 20 by the circulation fan 40 flows from the adsorption tower 30 into the catalyst filter unit 70 via the main heater 52. To do. Since the hot air immediately after being heated by the main heater 52 flows into the catalyst filter part 70, the catalyst temperature of the catalyst filter part 70 also becomes high, and the organic matter contained in the hot air is decomposed with high efficiency. That is, by disposing the catalyst filter unit 70 after the main heater 52, the temperature drop of the hot air from the main heater 52 to the catalyst filter unit 70 is reduced, and the decomposition efficiency of the catalyst filter unit 70 is increased. If an atmosphere containing oxygen or heated air is circulated as hot air, thermal decomposition and oxidative decomposition of organic matter occur simultaneously in the catalyst filter unit 70. For this reason, the temperature of the catalyst filter 71 is further increased by the heat generated by the oxidative decomposition, and the decomposition efficiency of the organic matter can be further increased.

  Even in the third embodiment, a separate heater for heating the catalyst becomes unnecessary, and heat loss can be reduced. Further, since the firing temperature inside the furnace body 10 can be adjusted by controlling only the main heater 52, temperature control is facilitated and a stable firing temperature can be obtained.

<4. Fourth Embodiment>
Next, a fourth embodiment of the present invention will be described. FIG. 4 is a diagram showing an overall configuration of a circulation type substrate firing furnace of the fourth embodiment. In FIG. 4, the same elements as those in the second embodiment and the third embodiment are denoted by the same reference numerals. The circulating substrate baking furnace of the fourth embodiment is different from that of the third embodiment in that the catalyst filter unit 70 includes a light source 72 in addition to the catalyst filter 71.

In the fourth embodiment, as in the third embodiment, a catalyst filter unit 70 is provided in the circulation path 20 downstream from the main heater 52 and reaching the furnace body 10. As in the second embodiment, titanium oxide (TiO ₂ ) functioning as a photocatalyst is mixed in a part of the catalyst carried by the catalyst filter 71. The light source 72 included in the catalyst filter unit 70 irradiates the catalyst filter 71 with light. The photocatalyst carried on the catalyst filter 71 exhibits catalytic action by receiving light from the light source 72. The remaining configuration of the substrate baking furnace of the fourth embodiment is the same as that of the third embodiment.

  The operation content in the substrate baking furnace of the fourth embodiment is also substantially the same as that of the third embodiment, and similarly to the third embodiment, heat loss can be suppressed to a low level and a stable baking temperature can be obtained. In the fourth embodiment, light is emitted from the light source 72 to the catalyst filter 71 at an appropriate timing. If it does in this way, the photocatalyst of the catalyst filter 71 will receive a light, will show a catalytic action, and the organic substance which remained partly on the metal filter can be decompose | disassembled efficiently. That is, a kind of cleaning process can be performed by irradiating the catalyst filter 71 with light from the light source 72.

<5. Fifth Embodiment>
Next, a fifth embodiment of the present invention will be described. FIG. 5 is a diagram showing an overall configuration of a circulation type substrate firing furnace of the fifth embodiment. In FIG. 5, the same elements as those in the first embodiment are denoted by the same reference numerals. The difference between the circulating substrate baking furnace of the fifth embodiment and the first embodiment is the arrangement position of the catalyst filter unit 70.

  As shown in FIG. 5, in the fifth embodiment, a catalyst filter unit 70 is provided in each of the two flow paths 20a and 20b in which the adsorption towers 30 and 30 are provided. The remaining configuration of the substrate baking furnace of the fifth embodiment is the same as that of the first embodiment.

  In the fifth embodiment, the hot air discharged from the hot air exhaust port 14 of the furnace body 10 and circulated in the circulation path 20 by the circulation fan 40 flows from the catalyst filter unit 70 through the adsorption tower 30 to the main heater 52. To do. The passing sequence of the hot air itself is the same as that in the first embodiment. Therefore, similarly to the first embodiment, it is possible to suppress heat loss and obtain a stable firing temperature.

  In addition, in the fifth embodiment, since the catalyst filter unit 70 is provided in each of the two flow paths 20a and 20b, the adsorption tower 30 used by the four butterfly dampers 31a, 31b, 32a and 32b is provided. The catalyst filter unit 70 used at the same time as switching is also switched. For this reason, maintenance and cleaning of the catalyst filter unit 70 can be performed together with the regeneration processing of the adsorption tower 30, and it is not necessary to stop the substrate baking furnace for maintenance of the catalyst filter unit 70, and the substrate baking is performed. The operating rate of the furnace can be improved. Note that it is not always necessary to perform maintenance of the adsorption tower 30 and the catalyst filter unit 70 at the same timing, and only one of the maintenance may be performed according to each maintenance cycle.

<6. Sixth Embodiment>
Next, a sixth embodiment of the present invention will be described. FIG. 6 is a diagram illustrating an overall configuration of a circulation type substrate baking furnace according to the sixth embodiment. In FIG. 6, the same elements as those in the second embodiment and the fifth embodiment are denoted by the same reference numerals. The sixth embodiment is different from the fifth embodiment in that the catalyst filter unit 70 includes a light source 72 in addition to the catalyst filter 71.

In the sixth embodiment, as in the fifth embodiment, the catalyst filter unit 70 is provided in each of the two flow paths 20a and 20b in which the adsorption towers 30 and 30 are provided. As in the second embodiment, titanium oxide (TiO ₂ ) functioning as a photocatalyst is mixed in a part of the catalyst carried by the catalyst filter 71. The light source 72 included in the catalyst filter unit 70 irradiates the catalyst filter 71 with light. The photocatalyst carried on the catalyst filter 71 exhibits catalytic action by receiving light from the light source 72. The remaining configuration of the substrate baking furnace of the sixth embodiment is the same as that of the fifth embodiment.

  The operation content in the substrate baking furnace of the sixth embodiment is also substantially the same as that of the fifth embodiment, and similarly to the fifth embodiment, heat loss can be suppressed to a low level and a stable baking temperature can be obtained. In the sixth embodiment, light is emitted from the light source 72 to the catalyst filter 71 at an appropriate timing. If it does in this way, the photocatalyst of the catalyst filter 71 will receive a light, will show a catalytic action, and the organic substance which remained partly on the metal filter can be decompose | disassembled efficiently. That is, a kind of cleaning process can be performed by irradiating the catalyst filter 71 with light from the light source 72.

<7. Seventh Embodiment>
Next, a seventh embodiment of the present invention will be described. In the seventh embodiment, an absorption tower 60 including an absorbent 61 that absorbs carbon dioxide at a relatively high temperature is provided instead of the adsorption tower 30 filled with an adsorbent that adsorbs carbon dioxide and moisture. . FIG. 7 is a diagram showing an absorption tower 60 of the seventh embodiment. In FIG. 7, the same elements as those in the first embodiment are denoted by the same reference numerals.

The two absorption towers 60 and 60 are provided in parallel in the circulation path 20. Similarly to the first embodiment, the circulation path 20 is branched into two flow paths 20a and 20b in a part of the path, and the absorption tower 60 is provided in each of the branched two flow paths 20a and 20b. Is provided. The two flow paths 20a and 20b branched in two are merged again. Each absorption tower 60 includes an absorber 61 that absorbs carbon dioxide at a relatively high temperature. In the seventh embodiment, lithium silicate (Li ₄ SiO ₄ ) is used as the absorber 61. For example, as disclosed in JP-A-2006-102561, lithium silicate absorbs carbon dioxide even in a temperature range from room temperature to 400 ° C. The firing temperature in the furnace body 10 is approximately 200 ° C. to 300 ° C., which is within the temperature range where the lithium silicate absorbs carbon dioxide. Therefore, the absorbent 61 can absorb and remove carbon dioxide from the hot air flowing through the circulation path 20.

  Each absorption tower 60 includes a discharge heater 62 for discharging absorbed carbon dioxide from the absorbent 61 and a recovery system 64 for recovering carbon dioxide released from the absorbent 61. Lithium silicate has a property of releasing carbon dioxide when heated to a temperature higher than the temperature range in which carbon dioxide is absorbed. Therefore, when the release heater 62 heats the absorbent 61 that has absorbed carbon dioxide, the absorbed carbon dioxide is released from the absorbent 61. The recovery system 64 includes valves 63a and 63b, and recovers carbon dioxide released from the absorbent 61 by opening both valves 63a and 63b. Specifically, a carrier gas (for example, nitrogen gas) is supplied to the absorbent material 61 by opening the valve 63b. Carbon dioxide released from the heated absorbent 61 is collected together with the carrier gas by opening the valve 63a.

  As in the first embodiment, the two absorption towers 60, 60 are alternatively used. That is, the hot air flow paths 20a and 20b are selectively switched by the four butterfly dampers 31a, 31b, 32a and 32b, and the hot air flowing through the circulation path 20 is only one of the two absorption towers 60 and 60. Will pass. Except for the point that the adsorption tower 30 is replaced with the absorption tower 60, the configuration of the substrate baking furnace of the seventh embodiment is the same as that of the first embodiment.

  The operation content in the substrate baking furnace of the seventh embodiment is also substantially the same as that of the first embodiment. That is, hot air discharged from the hot air exhaust port 14 of the furnace body 10 and circulated in the circulation path 20 by the circulation fan 40 flows from the catalyst filter unit 70 through the absorption tower 60 into the main heater 52. The hot air discharged from the furnace body 10 flows into the catalyst filter unit 70 as it is, and the organic matter contained in the hot air is decomposed, so that a separate heater for heating the catalyst becomes unnecessary and heat loss is reduced. be able to. Further, since the firing temperature inside the furnace body 10 can be adjusted by controlling only the main heater 52, temperature control becomes easy and a stable firing temperature can be obtained.

  The butterfly dampers 31a, 31b, 32a, and 32b are switched so that the hot air circulated in the circulation path 20 passes through only one of the two absorption towers 60 and 60. Therefore, the hot air that has been decomposed by passing through the catalyst filter unit 70 flows into one of the two absorption towers 60, 60, and is subjected to carbon dioxide removal processing.

  As in the first embodiment, the absorption tower 60 to be used is switched at an appropriate timing. That is, the control unit 90 controls the switching timing of the four butterfly dampers 31a, 31b, 32a, and 32b so that the hot air alternately passes through the two absorption towers 60 and 60.

  After the absorption tower 60 to be used is switched, the regeneration process of the absorption tower 60 used so far is performed. The regeneration process of the absorption tower 60 is to heat the absorbent 61 with the discharge heater 62 and open the valves 63a and 63b. As a result, the absorbed carbon dioxide is released from the absorbent material 61, and the released carbon dioxide is recovered by the recovery system 64.

  Eventually, the four butterfly dampers 31a, 31b, 32a, and 32b are switched again by the control unit 90 so that the hot air passes through the absorption tower 60 that has been regenerated. And the regeneration process of the other absorption tower 60 is performed similarly. If it does in this way, it will become possible to operate continuously, without stopping a substrate baking furnace.

  The absorption tower 60 can be used in place of the adsorption tower 30 in all of the first to sixth embodiments (FIGS. 1 to 6). That is, the circulation path 20 may have a configuration in which a trap tower for trapping carbon dioxide and / or moisture is provided in each of the two flow paths 20a and 20b branched in a part of the path.

<8. Modification>
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 each of the above embodiments, a trap tower (adsorption tower 30 or absorption tower 60) is provided in parallel in the middle of the circulation path 20, and the other regeneration process is performed while one of the trap towers is being used. Although the operation rate of the substrate baking furnace has been improved, only one trap tower may be provided in the middle of the circulation path 20. Even if it does in this way, like the above-mentioned each embodiment, heat loss can be suppressed few and stable calcination temperature can be obtained.

  In the second, fourth, and sixth embodiments, the catalytic filter 71 may be caused to catalyze using light from an indoor lighting fixture or the like without providing the light source 72.

  Moreover, in 1st Embodiment-6th Embodiment, although activated carbon was used as an adsorbent of the adsorption tower 30, it is not limited to this, What is a raw material which adsorb | sucks a carbon dioxide and / or a water | moisture content. For example, silica gel or zeolite may be used. As the adsorbent, a polymer film or an inorganic film such as a zeolite film, a silica film, or a carbon film may be used.

  Further, sintered ceramics may be used in place of the metal filter 54 of each of the above embodiments. Furthermore, the metal filter 54 is not necessarily provided if the catalyst filter unit 70 has a sufficient filter function and can reliably remove organic substances and particles. However, when the circulation fan 40 and the main heater 52 are provided downstream of the catalyst filter unit 70 as in the first, second, fifth, and sixth embodiments, particles generated from them are removed. For the purpose, it is preferable to attach a metal filter 54 to the hot air inlet 12 of the furnace body 10.

  Further, in each of the above embodiments, the system is a system in which the circulation path 20 of the substrate baking furnace is completely closed. However, an atmosphere exchange mechanism for introducing a new atmosphere while discharging a part of the atmosphere may be provided. good.

  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.

  Further, the substrate to be baked by the circulating substrate baking furnace according to the present invention is not limited to the glass substrate W, and may be a semiconductor wafer. The material to be baked on the substrate is not limited to color inks and metal wiring materials. Bank materials, ITO electrode (indium tin oxide transparent electrode) materials, organic insulating film materials, light transmission Various organic film materials and various inks having an organic solvent may be used.

It is a figure which shows the whole structure of the circulation type substrate baking furnace of 1st Embodiment. It is a figure which shows the whole structure of the circulation type substrate baking furnace of 2nd Embodiment. It is a figure which shows the whole structure of the circulation type substrate baking furnace of 3rd Embodiment. It is a figure which shows the whole structure of the circulation type substrate baking furnace of 4th Embodiment. It is a figure which shows the whole structure of the circulation type substrate baking furnace of 5th Embodiment. It is a figure which shows the whole structure of the circulation type substrate baking furnace of 6th Embodiment. It is a figure which shows the absorption tower of 7th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Furnace main-body part 12 Hot-air introduction port 14 Hot-air exhaust port 20 Circulation path | route 20a, 20b Flow path 30 Adsorption tower 31a, 31b, 32a, 32b Butterfly damper 40 Circulation fan 52 Main heater 54 Metal filter 60 Absorption tower 62 Heating heater 64 Recovery system 70 Catalytic filter unit 71 Catalytic filter 72 Light source 90 Control unit

Claims (10)

A circulation type substrate baking furnace that circulates hot air to perform substrate baking processing,
A furnace body body for accommodating the substrate therein;
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 main heater for heating hot air circulated through the circulation path;
A catalyst filter portion provided in the circulation path and having a metal filter for supporting a catalyst;
Trap means provided in the circulation path for trapping carbon dioxide and / or moisture;
A circulation type substrate firing furnace characterized by comprising: In the circulation type substrate firing furnace according to claim 1,
The trap means includes two trap towers provided in parallel to two flow paths that are bifurcated in the middle of the circulation path and merge again.
Switching means for selectively switching the two flow paths so that hot air passes through one of the two trap towers;
A switching control unit for controlling the switching timing of the switching means;
A circulation type substrate baking furnace characterized by comprising: In the circulation type substrate firing furnace according to claim 2,
The circulating trapping furnace is characterized in that the two trap towers are two adsorption towers that adsorb carbon dioxide and / or moisture. In the circulation type substrate firing furnace according to claim 2,
The circulating trapping furnace is characterized in that the two trap towers are two absorption towers that absorb carbon dioxide. In the circulation type substrate firing furnace according to claim 4,
Each of the two absorption towers is
Carbon dioxide absorber,
A release heater for releasing the absorbed carbon dioxide from the absorbent;
A recovery system for recovering carbon dioxide released from the absorbent;
A circulation type substrate firing furnace characterized by comprising: In the circulation type substrate firing furnace according to any one of claims 1 to 5,
The circulation type substrate firing furnace, wherein the catalyst filter part is provided in the circulation path downstream from the furnace body main part and to the trap means. In the circulation type substrate firing furnace according to any one of claims 1 to 5,
The circulation type substrate firing furnace, wherein the catalyst filter part is provided in the circulation path downstream from the main heater and to the furnace body main part. In the circulation type substrate firing furnace according to any one of claims 2 to 5,
The circulation type substrate firing furnace, wherein the catalyst filter section is provided in each of the two flow paths. In the circulation type substrate firing furnace according to any one of claims 1 to 8,
The catalyst comprises a photocatalyst;
The circulation type substrate firing furnace, wherein the catalyst filter section includes light irradiation means for irradiating the photocatalyst with light. In the circulation type substrate firing furnace according to any one of claims 1 to 9,
A circulation type substrate firing furnace comprising a metal filter at a hot air inlet of the furnace body.

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