JP2016186389A - Firing furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a firing furnace which heats and fires a substrate in a uniform manner without heating a device to a high temperature despite of having a simple structure.SOLUTION: A firing furnace includes: a furnace body 10 made of stainless steel; lamp heaters 13 disposed below a substrate 100; a water-cooling cooling plate 11 disposed below the lamp heaters 13; lamp heaters 14 disposed above the substrate 100; and a water-cooling cooling plate 12 disposed above the lamp heaters 14. When the substrate 100 is heated, exhaust airflow, which flows from an opening part 25 formed at a lower part of a heat insulation plate 21 and an opening part 15 formed at a lower part of the furnace body 10 and reaches an exhaust port 17 through a firing space of the furnace body 10, is formed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a firing furnace for heating a substrate housed in a firing space.

  To improve performance when processing glass substrates for organic EL display devices, glass substrates for liquid crystal display devices, panel substrates for solar cells, glass substrates for plasma displays, glass substrates for photomasks, substrates for optical disks, semiconductor wafers, etc. It is necessary to perform firing (annealing). In the case of performing this firing, lamp annealing using a lamp heater is performed in a process that requires rapid heating of the substrate. When such lamp annealing is performed in the atmosphere, the atmosphere is heated by the heat from the peripheral parts heated by the lamp heater or the heat from the lamp heater itself, and the heat is accumulated, and the entire firing furnace is The problem of extremely high temperatures arises.

  For this reason, there is a heat insulation mechanism that reduces heat transfer to the outside by using a quartz tank as the furnace body and evacuating the furnace body for heat insulation or purging and cooling the furnace body with nitrogen gas after heating. It has been adopted.

  Moreover, in patent document 1, while arrange | positioning the heating chamber which heat-processes a to-be-heated object with a lamp heater inside a furnace body, hot air is supplied in a furnace with a hot air supply means, and the inside of a furnace is set to predetermined temperature. A heating apparatus is disclosed in which the temperature of the object to be heated is prevented from being conducted to the conveyor or the temperature of the heating chamber is lowered due to the outside air flowing into the heating chamber by raising the temperature.

JP 2009-236371 A

  When the above-described heat insulation mechanism using the quartz tank is employed, there arises a problem that the apparatus becomes extremely expensive. On the other hand, in the heating apparatus described in Patent Document 1, even if the object to be heated can be uniformly heat-treated, it is impossible to prevent the entire apparatus from becoming high temperature.

  The present invention has been made to solve the above-mentioned problems, and provides a firing furnace capable of uniformly heating and firing a substrate without increasing the temperature of the apparatus while having a simple configuration. Objective.

  The invention according to claim 1 is a firing furnace for heating a substrate housed in a firing space, and a stainless steel furnace body for forming the firing space, and a support for supporting the substrate in the firing space. A member, a lamp heater for heating a substrate disposed in the firing space and supported by the support member, an opening formed in a lower portion of the furnace body, and an exhaust formed in an upper portion of the furnace body An exhaust flow forming means for forming an exhaust flow for thermally exhausting radiant heat generated by the lamp heater by flowing from the opening toward the exhaust port, and disposed in the firing space; A contact suppressing member that suppresses contact of the exhaust flow with the lamp heater.

  According to a second aspect of the present invention, in the first aspect of the present invention, the contact suppressing member includes a water-cooled cooling plate.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the first lamp heater disposed below the substrate supported by the support member, and the first lamp heater. A first contact suppression member disposed below the second lamp heater, a second lamp heater disposed above the substrate supported by the support member, and a second lamp heater disposed above the second lamp heater. A second contact suppression member.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, a heat insulating plate is disposed at a position separated from the surface of the furnace body by a predetermined distance in the outer peripheral portion of the furnace body. did.

  The invention according to claim 5 is the invention according to claim 4, wherein an opening is formed in the heat insulating plate, and the opening is irradiated outward from the opening formed in the furnace body. It is arranged at a position where the light from the lamp heater is not irradiated.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, a mesh member that covers the opening is attached to the opening formed in the furnace body.

  A seventh aspect of the present invention includes the temperature sensor according to any one of the first to sixth aspects, wherein the temperature sensor measures the temperature of the exhaust flow discharged from the exhaust port.

  The invention according to claim 8 is the invention according to any one of claims 1 to 7, wherein the support member includes a support part for supporting the substrate and a grip part connected to the support part. The support part and the grip part are connected via a heat insulating member.

  According to the first to third aspects of the present invention, the exhaust flow formed by the airflow forming means can prevent the apparatus from becoming high temperature while having a simple configuration. In addition, the substrate can be uniformly heated and fired by the action of the contact suppressing member.

  According to invention of Claim 4, it becomes possible to suppress the spreading | diffusion of the thermal radiation from an apparatus to the exterior by the effect | action of a heat insulation board.

  According to the fifth aspect of the present invention, it is possible to prevent light from the lamp heater from leaking to the outside.

  According to the sixth aspect of the present invention, it is possible to prevent foreign matters from entering the furnace body.

  According to the seventh aspect of the present invention, the temperature in the furnace body can be monitored based on the temperature of the exhaust flow measured by the sensor. Accordingly, warning display or the like can be performed, and the flow rate of the exhaust flow can be determined or controlled based on the temperature of the exhaust flow measured by the sensor.

  According to invention of Claim 8, it becomes possible to prevent that a holding part becomes high temperature by the effect | action of a heat insulation member.

It is a longitudinal cross-sectional schematic diagram of the baking furnace which concerns on this invention. It is a perspective view which shows the structure in the furnace body 10 in the baking furnace which concerns on this invention with the work tray 30 as a supporting member. 1 is a schematic plan view of a firing furnace according to the present invention. 3 is a front view showing a positional relationship between an opening 15 formed in the lower part of the furnace body 10 and an opening 25 formed in the lower part of the heat insulating plate 21. FIG. It is a schematic diagram which shows the water cooling mechanism for cooling the cooling plates 11 and 12. FIG. It is a temperature rising profile which shows the temperature change of the board | substrate 100 heated by the lamp heaters 13 and 14 in the baking space. It is a graph which shows the relationship between the exhaust temperature measured by the temperature sensor 28 at the time of heat-processing the board | substrate 100, and the room temperature where the baking furnace at that time was arrange | positioned.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic longitudinal sectional view of a firing furnace according to the present invention. FIG. 2 is a perspective view showing a structure in the furnace body 10 in the firing furnace according to the present invention together with a work tray 30 as a support member. FIG. 3 is a schematic plan view of a firing furnace according to the present invention. Note that FIG. 3 shows a schematic plan view in plan view from the height position where the substrate 100 is disposed.

  The firing furnace according to the present invention is for firing by heating a silicon square substrate 100 for solar cells (hereinafter simply referred to as “substrate 100”), and for forming a firing space therein. A stainless steel furnace body 10, a work tray 30 as a support member for supporting the substrate 100 in the firing space, and a first lamp heater disposed below the substrate 100 supported by the work tray 30. A plurality of lamp heaters 13, a water-cooled cooling plate 11 as a first contact suppressing member disposed below these lamp heaters 13, and a substrate 100 supported by a work tray 30. The plurality of lamp heaters 14 as the second lamp heaters and the water cooling as the second contact suppressing member disposed above the lamp heaters 14. And a cooling plate 12.

  The plurality of lamp heaters 13 and 14 are composed of halogen lamps. The lamp heater 13 and the lamp heater 14 are arranged in directions orthogonal to each other. A reflector 23 (see FIG. 2) is disposed outside the lamp heaters 13 and 14. These lamp heaters 13 and 14 are arranged on the upper side and the lower side with respect to the substrate 100 supported by the work tray 30. The lamp heaters 13 and 14 and the cooling plates 11 and 12 are supported by a frame 29 shown in FIG.

  As shown in FIG. 1, a stainless steel heat insulating plate 21 is disposed at a position separated from the surface of the furnace body 10 by a predetermined distance in the outer peripheral portion of the furnace body 10. These heat insulating plates 21 are disposed on five surfaces other than the lower surface of the furnace body 10 having a substantially cubic shape. These heat insulating plates 21 are arranged at positions spaced apart from the surface of the furnace body 10 by a predetermined distance in the outer peripheral portion of the furnace body 10 via the spacers 22.

  As shown in FIG. 1, openings 15 for taking in outside air are formed at lower portions of four side surfaces of a furnace body 10 having a substantially cubic shape. A mesh member 16 is attached to the opening 15. Moreover, the opening part 25 for taking in external air is formed in the lower part of the four heat insulation board 21 arrange | positioned facing the four side surfaces of the furnace body 10 which makes | forms a substantially cubic shape.

  FIG. 4 is a front view showing the positional relationship between the opening 15 formed in the lower part of the furnace body 10 and the opening 25 formed in the lower part of the heat insulating plate 21.

  As shown in FIG. 4, the opening 15 formed in the lower portion of the furnace body 10 is formed at a lower position in front view than the opening 25 formed in the lower portion of the heat insulating plate 21. For this reason, the light from the lamp heaters 13 and 14 leaking out of the furnace body 10 from the opening 15 formed in the furnace body 10 is blocked by the heat insulating plate 21, and this light is formed in the heat insulating plate 21. The opening 25 is not irradiated. Thereby, it is possible to prevent light from the lamp heaters 13 and 14 from leaking outside the firing furnace.

  In this embodiment, the opening 15 formed in the lower part of the furnace body 10 is formed at a position lower than the opening 25 formed in the lower part of the heat insulating plate 21, so Although the light is prevented from leaking to the outside of the firing furnace, the lamp heater is formed by shifting the opening 15 formed in the furnace body 10 and the opening 25 formed in the heat insulating plate 21 laterally. Light from 13 and 14 may be prevented from leaking outside the firing furnace.

  As shown in FIG. 1, an exhaust port 17 is formed in the upper part of the furnace body 10. The exhaust port 17 is connected to a factory exhaust pipe (not shown). A temperature sensor 28 for measuring the temperature of the exhaust flow passing through the exhaust port 17 is disposed in the exhaust port 17. When exhaust is performed from the exhaust port 17 by the factory exhaust pipe, the opening 25 formed in the lower part of the heat insulating plate 21 and the opening 15 formed in the lower part of the furnace body 10 An exhaust flow reaching the exhaust port 17 through the firing space is formed. As this exhaust flow forming means, a fan, a blower or the like may be used instead of the factory exhaust pipe.

  On the side surface of the furnace body 10, a loading / unloading port 18 for inserting the substrate 100 into the firing space in the furnace body 10 is formed. A shutter 19 is disposed in front of the loading / unloading port 18. The shutter 19 can swing between a closed position of the carry-in / out port 18 shown by a solid line in FIG. 1 and a release position of the carry-in / out port 18 shown by a virtual line.

  As shown in FIG. 2, the work tray 30 as a support member that supports the substrate 100 in the firing space in the furnace body 10 is in a state in which the substrate 100 is supported via the carry-in / out port 18 shown in FIG. 1. Invade the body 10. As shown in FIG. 2, the work tray 30 includes a frame 31 and a support arm 32 for the substrate 100, a support portion that supports the substrate 100, a stainless bar member 33 that is connected to the support portion, and a heat insulator. And a rod member 35 made of stainless steel and a rod member 35 made of stainless steel. The rod-shaped member 35 made of stainless steel constitutes the grip portion according to the present invention. The rod-shaped member 34 having heat insulating properties is composed of a heat insulating member such as a low thermal conductive ceramic, for example. The substrate 100 is carried into the firing space in the furnace body 10 via the carry-in / out opening 18 of the furnace body 10 while being supported by the support part in the work tray 30 and supported by the support part in the work tray 30. Heated in a heated state.

  FIG. 5 is a schematic diagram showing a water cooling mechanism for cooling the cooling plates 11 and 12 described above.

  The cooling plate 11 and the cooling plate 12 are connected to a chiller 41, which is a water-cooled cooling device, via pipe lines 42, 43, and 44. The cooling water cooled by the chiller 41 is sent to the cooling plate 12 via the pipe line 42, and after cooling the cooling plate 12, it is sent to the cooling plate 11 via the pipe line 43. After cooling the cooling plate 11, this cooling water is sent to the chiller 41 through the pipe 44 and is cooled again in the chiller 41.

  Next, a firing operation for firing by heating the substrate 100 using the firing furnace having the above configuration will be described.

  In the case of baking the substrate 100 using the baking furnace described above, first, the shutter 19 is moved to the release position indicated by the phantom line in FIG. Then, as shown in FIG. 2, the work tray 30 is disposed in the firing space in the furnace body 10 while supporting the substrate 100. In this state, the frame 31 in the work tray 30 is supported by the support portion 27. Then, the shutter 19 is moved to the closed position indicated by the solid line in FIG. At this time, in order to avoid interference between the shutter 19 and the rod-like member 33 in the work tray 30, a notch or the like (not shown) is formed in the shutter 19.

  In this state, the lamp heaters 13 and 14 are turned on to heat the substrate 100. At this time, exhaust in the furnace body 10 is performed simultaneously. That is, by the action of the factory exhaust pipe connected to the exhaust port 17, the opening 25 formed in the lower part of the heat insulating plate 21 and the lower part of the furnace body 10 are formed as indicated by an arrow L in FIGS. 1 and 3. An exhaust flow from the opening 15 to the exhaust port 17 through the firing space in the furnace body 10 is formed. By this exhaust flow, the radiant heat generated by the lamp heaters 13 and 14 is thermally exhausted, and the temperature of the furnace body 10 is prevented from becoming excessively high. Even if the temperature of the furnace body 10 rises to some extent, heat is released from the entire firing furnace to the external region by the action of the heat insulating plate 21 disposed at a position separated from the surface of the furnace body 10 by a predetermined distance. Can be made small.

  At this time, the temperature of the exhaust flow discharged to the outside from the exhaust port 17 is measured by the temperature sensor 28. When the temperature measured by the temperature sensor 28 exceeds the set temperature, an error message or the like is displayed. A flow rate adjusting mechanism such as a damper may be provided between the exhaust port 17 and the factory exhaust pipe, and the flow rate of the exhaust flow may be controlled based on the temperature of the exhaust flow measured by the temperature sensor 28. Further, the exhaust flow rate may be set based on the temperature measured by the temperature sensor 28 before the substrate 100 is fired.

  A cooling plate 11 is disposed below the plurality of lamp heaters 13 disposed below the substrate 100 supported by the work tray 30, and disposed above the substrate 100 supported by the work tray 30. A water-cooled cooling plate 12 is disposed above the plurality of lamp heaters 14. For this reason, it becomes possible to prevent the exhaust flow passing through the firing space in the furnace body 10 from contacting the lamp heater 13 and the lamp heater 14. Thereby, cooling of the lamp heater 13 and the lamp heater 14 is prevented. In addition, the action of the cooling plates 11 and 12 can prevent the temperature inside the furnace body 10 from rising.

  At this time, the cooling plate 11 is disposed on the opposite side of the lamp heater 13 from the substrate 100, and the cooling plate 12 is disposed on the opposite side of the lamp heater 14 from the substrate 100. For this reason, the cooling effect by the action of the cooling plates 11 and 12 does not affect the heating action of the substrate 100 by the lamp heaters 13 and 14.

  When the furnace body 10 is cooled by the above-described exhaust flow, outside air is taken in through the opening 15 for taking in outside air formed in the lower part of the side surface of the furnace body 10. As described above, the mesh member 16 is attached to the opening 15. For this reason, foreign matter can be prevented from entering the firing space in the furnace body 10 from the outside, and the substrate 100 can be fired in a clean state.

  FIG. 6 is a temperature rise profile showing a temperature change of the substrate 100 heated by the lamp heaters 13 and 14 in the firing space. In this figure, the vertical axis indicates the temperature (° C) of the substrate 100, and the horizontal axis indicates time (seconds).

  After the lamp heaters 13 and 14 are turned on, the temperature of the substrate 100 gradually rises to about 400 degrees Celsius, and the temperature is maintained for a certain time. The lamp heaters 13 and 14 are set to the maximum output only during the time t. As a result, the temperature of the substrate 100 rapidly rises to about 800 degrees Celsius. Thereafter, the outputs of the lamp heaters 13 and 14 are lowered, and the temperature of the substrate 100 is gradually lowered. Then, after the time T has elapsed, the lamp heaters 13 and 14 are turned off, and the firing process by heating the substrate 100 in one cycle is completed. The time t described above is, for example, about 4 seconds, and the time T is, for example, about 60 seconds.

  When the heat treatment for one substrate 100 is completed, the shutter 19 is moved from the position indicated by the solid line in FIG. 1 to the position indicated by the phantom line, and the substrate 100 after baking is fired in the furnace body 10 together with the work tray 30. Remove from space. At this time, the frame 31 constituting the support portion of the substrate 100 in the work tray 30 is made of a stainless steel rod-shaped member 33, a heat-insulating rod-shaped member 34, and a stainless steel material constituting the gripping portion according to the present invention. The rod-shaped member 35 is connected in this order. For this reason, it becomes possible to prevent that the temperature of the rod-shaped member 35 as a grip part rises by the effect | action of the rod-shaped member 34 which has heat insulation. For this reason, the operator can easily take out the substrate 100 from the furnace body 10 by gripping the rod-shaped member 35. Then, the operator carries the substrate 100 to be fired next into the firing space in the furnace body 10 using the work tray 30.

  FIG. 7 is a graph showing the relationship between the exhaust temperature measured by the temperature sensor 28 when the substrate 100 is continuously heat-treated and the room temperature at which the firing furnace is disposed. In this figure, the vertical axis represents temperature (° C.), and the horizontal axis represents time (seconds). In this figure, symbol A indicates the time when the lamp heaters 13 and 14 are turned on, symbol B indicates the time when the shutter 19 is opened for loading and unloading the substrate 100, and symbol C indicates that the lamp heaters 13 and 14 are turned off. Shows the time.

  As shown in this figure, the exhaust temperature rises when the lamp heaters 13 and 14 are turned on, and the exhaust temperature falls when the lamp heaters 13 and 14 are turned off. When the shutter 19 is opened, the high-temperature gas between the lamp heater 13 and the lamp heater 14 in the furnace body 10 is exhausted, so that the exhaust temperature temporarily rises. At this time, since the heat treatment of the substrate 100 has been completed, this does not affect the treatment result of the substrate 100.

  As shown in this figure, the firing furnace according to the present invention can prevent the exhaust temperature from rising. When the heat treatment of the substrate 100 is further continued, the temperature of the exhaust flow before the lamp heaters 13 and 14 are turned on is saturated at a temperature of about 25 degrees Celsius.

  In the above-described embodiment, the present invention was invented for a case where the present invention is applied to a firing furnace for firing by heating silicon square substrates 100 for solar cells one by one. The present invention may be applied to a baking furnace for baking a substrate other than the substrate or a baking furnace for baking a large number of substrates at once.

DESCRIPTION OF SYMBOLS 10 Furnace 11 Cooling plate 12 Cooling plate 13 Lamp heater 14 Lamp heater 15 Opening part 16 Net-like member 17 Exhaust port 18 Carrying in / out port 19 Shutter 21 Heat insulation board 22 Spacer 25 Opening part 28 Temperature sensor 30 Work tray 31 Frame body 32 Support arm 34 Bar-shaped member 35 Bar-shaped member 41 Chiller 42 Pipe line 43 Pipe line 44 Pipe line 100 Substrate

Claims (8)

A firing furnace for heating a substrate housed in a firing space,
A stainless steel furnace body for forming the firing space;
A support member for supporting the substrate in the firing space;
A lamp heater for heating the substrate disposed in the firing space and supported by the support member;
An opening formed in a lower portion of the furnace body;
An exhaust port formed in an upper portion of the furnace body;
An exhaust flow forming means for forming an exhaust flow for thermally exhausting radiant heat generated by the lamp heater by flowing from the opening toward the exhaust port;
A contact suppressing member disposed in the firing space and suppressing contact of the exhaust flow with the lamp heater;
A firing furnace comprising: In the firing furnace according to claim 1,
The contact suppressing member is a firing furnace including a water-cooled cooling plate. In the firing furnace according to claim 1 or 2,
A first lamp heater disposed below a substrate supported by the support member;
A first contact suppression member disposed below the first lamp heater;
A second lamp heater disposed above the substrate supported by the support member;
A second contact suppression member disposed above the second lamp heater;
A firing furnace comprising: In the baking furnace in any one of Claims 1-3,
A firing furnace in which a heat insulating plate is disposed at a predetermined distance from the surface of the furnace body in the outer peripheral portion of the furnace body. In the firing furnace according to claim 4,
An opening is formed in the heat insulating plate, and the opening is disposed at a position where the light from the lamp heater irradiated from the opening formed in the furnace body is not irradiated. In the firing furnace according to claim 5,
A firing furnace in which a mesh member covering the opening is attached to the opening formed in the furnace body. In the baking furnace in any one of Claims 1-6,
A firing furnace provided with a temperature sensor for measuring the temperature of the exhaust flow discharged from the exhaust port. In the baking furnace in any one of Claims 1-7,
The support member includes a support part for supporting the substrate, and a grip part connected to the support part,
The said support part and the said holding part are the baking furnaces connected via a heat insulation member.

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