JP2022002251A - Heat treatment device - Google Patents

Abstract

To provide a vertical heat treatment device with suppressed heat radiation from an opening on a container bottom side and reduced heat deviation in a horizontal direction in a bottom zone, to enable reduction in manufacturing costs and operation costs of the heat treatment device, and to make it possible to secure a state in which thermal uniformity of an object to be treated is high regardless of a thermal treatment condition.SOLUTION: A heat treatment device 1 includes: a heater 22 disposed around a tube 3; a rack 43 having a configuration in which a plurality of support parts 51 for supporting objects 100 to be treated are provided; a heat ray reflection member 5 which is disposed below a lowermost one of the objects 100 to be treated, and is used for reflecting a heat ray from the heater 22 to the objects 100 to be treated supported by the rack 43; and a displacement mechanism 7 for vertically changing a position of the heat ray reflection member 5.SELECTED DRAWING: Figure 1

Description

The present invention relates to a heat treatment apparatus for treating an object to be treated in a heated atmosphere.

A heat treatment apparatus for heat-treating a wafer for semiconductor manufacturing is known (see, for example, Patent Document 1). The heat treatment apparatus described in Patent Document 1 is a vertical furnace. This vertical furnace has a quartz heat treatment vessel arranged inside the furnace. A plurality of substrates to be processed such as semiconductor wafers mounted on a boat are carried into this container. Then, after gas purging the inside of the container with the inert gas, the treatment gas is injected into the container to perform heat treatment. In such a vertical heat treatment apparatus, an opening is formed at the bottom of the container to form an entrance / exit of the substrate to be processed. Since it is easy to dissipate heat from this opening in a heat treatment device, in order to suppress heat dissipation during heat treatment, a heat insulating structure is formed by vertically arranging a plurality of horizontally oriented heat shield plates in the above opening. ing.

Japanese Unexamined Patent Publication No. 2005-217383

As described above, it is required to suppress heat dissipation from the opening on the bottom side of the container of the vertical furnace. As such a configuration, in addition to the configuration described in Patent Document 1, a configuration in which a quartz box containing quartz wool is installed in the opening on the bottom side of the container can be considered. Further, as another configuration, a configuration in which a plurality of horizontally arranged heat insulating fins are vertically arranged in the opening on the bottom side of the container and a sub-heater is installed can be considered. The sub-heater is a heater different from the heater installed around the container to heat the atmosphere in the container.

Since the above-mentioned quartz box has high heat insulating performance, it is highly effective in suppressing heat dissipation from the opening, but the manufacturing cost is high. Further, the configuration using the sub-heater described above is inferior in heat insulating performance to the configuration using the quartz box. However, the sub-heater can exert a heat retaining function of the opening and also can exert a heat equalizing function of the bottom zone as an area near the opening (a function of reducing the bias of the temperature distribution in the horizontal direction). The soaking property of the bottom zone is important for the uniformity of heat treatment quality in the substrate to be treated arranged on the bottom zone side. However, since it is necessary to provide a sub-heater, the manufacturing cost and the operating cost such as the electricity cost are high.

Further, the target temperature of the substrate to be treated at the time of heat treatment differs depending on the type of heat treatment. Further, the conditions for ensuring the soaking property to the substrate to be treated at the time of heat treatment change depending on the attributes of the heat-treated substrate such as the size of the heat-treated substrate.

In view of the above circumstances, the present invention suppresses heat dissipation from the opening on the bottom side of the container in the vertical heat treatment apparatus, reduces the horizontal heat bias in the bottom zone, and further reduces the heat treatment apparatus. It is an object of the present invention that the manufacturing cost and the operating cost of the material can be reduced, and moreover, it is possible to secure a state in which the heat soaking property of the object to be treated is high regardless of the heat treatment conditions.

(1) In order to solve the above problems, the heat treatment apparatus according to a certain aspect of the present invention has a vertical container in which an opening for taking in and out an object to be taken in and out is arranged at the lower end, and around the container. A rack in which a plurality of arranged heaters and a plurality of support portions for supporting the object to be processed are provided vertically separated from each other and holding a plurality of the objects to be processed in the container, and the above. A heat ray reflecting member arranged below the lowermost object to be processed in the vertical direction and reflecting heat rays from the heater to the object to be processed supported by the rack, and a heat ray reflecting member for the rack. It has a displacement mechanism that displaces the heat ray reflecting member in order to change the position in the vertical direction.

According to this configuration, the heat ray reflecting member is arranged below the lowermost object to be processed. The heat ray reflecting member can reflect the heat rays from the heater arranged around the container toward the object to be processed. As a result, heat dissipation from the opening on the bottom side of the container can be suppressed, and as a result, the temperature difference (difference between the maximum value and the minimum value of the temperature) in the object to be processed arranged on the lowermost side can be suppressed. Can be made more even. That is, the heat equalizing function of the bottom zone (less deviation of the temperature distribution in the horizontal direction) as an area near the opening on the bottom side of the container can be exhibited. Moreover, since the simple configuration in which the heat ray reflecting member is installed is sufficient, it is not necessary to use a quartz box having a high manufacturing cost in order to suppress heat dissipation from the opening on the bottom side of the container, and the manufacturing cost of the heat treatment apparatus can be reduced. In addition, since the heat soaking property of the bottom zone can be increased without installing a sub-heater in the opening on the bottom side of the container, the manufacturing cost of the heat treatment apparatus can be reduced and the operating cost such as electricity cost can be reduced. Further, the vertical position of the heat ray reflecting member can be changed by the displacement mechanism. Thereby, for example, according to the target temperature of the object to be treated at the time of heat treatment and according to the attribute such as the size of the object to be treated, the heat ray reflecting member can make the temperature difference in the object to be smaller smaller. Can be placed. Based on the above, in the vertical heat treatment equipment, heat dissipation from the opening on the bottom side of the container is suppressed, heat unevenness in the horizontal direction in the bottom zone is reduced, and the manufacturing cost and operating cost of the heat treatment equipment are reduced. In addition, it is possible to secure a state in which the heat soaking property of the object to be treated is high regardless of the heat treatment conditions.

(2) The heat treatment apparatus further includes a temperature sensor for detecting the temperature around the lowermost object to be processed, and the displacement mechanism is based on the detected temperature detected by the temperature sensor. The heat ray reflecting member may be displaced in the vertical direction.

In this case, the heat ray reflecting member can be arranged at a position where the heat ray from the heater can be more evenly reflected to the object to be processed by the feedback control according to the actual temperature in the container. Therefore, the temperature difference in the object to be processed can be made smaller.

(3) The temperature sensor may detect the temperature in the region between the lowermost object to be processed and the heat ray reflecting member in the vertical direction.

In this case, the temperature sensor can more accurately detect the heat generated by the heat rays from the heat ray reflecting member to the object to be processed. Therefore, the displacement mechanism can arrange the heat ray reflecting member at a more appropriate height position by using the detected temperature information. As a result, the temperature difference in the lowermost object to be processed can be made smaller.

(4) The heater can be a temperature different from the temperature of the bottom heater arranged so as to surround the heat ray reflecting member and the temperature of the bottom heater arranged above the bottom heater so as to surround each of the support portions. The temperature sensor, including a center heater, may be located in an area surrounded by the center heater.

In this case, the temperature sensor is arranged in a region surrounded by the center heater, which is a region where abrupt temperature changes are relatively small because it is relatively far from the opening where heat dissipation is likely to occur. As a result, the temperature detection result of the temperature sensor does not become unstable. Therefore, it is possible to prevent hunting from occurring in the position control of the heat ray reflecting member.

(5) The heat treatment apparatus further includes a control unit that controls the displacement mechanism, and the control unit makes the heat ray reflecting member have a predetermined high reflection efficiency when the heater raises the temperature in the container. The heat ray reflecting member is arranged at a predetermined low reflection efficiency position when the temperature in the container is lowered, and the heat ray reflecting member directs the heat ray from the heater at the high efficiency reflection position. The efficiency of reflecting the heat rays to the object to be processed may be set higher than the efficiency of the heat ray reflecting member reflecting the heat rays from the heater to the object to be processed at the low efficiency reflection position.

In this case, when the heater raises the temperature inside the container, more heat rays from the heater can be reflected from the heat ray reflecting member to the object to be processed. Therefore, the temperature of the object to be treated can be raised (temperature rise) more quickly. Further, when the temperature inside the container is lowered due to the completion of the heat treatment of the object to be processed, the heat ray reflecting member can prevent the heat radiation from the object to be processed from interfering with the heat radiation. Therefore, the temperature of the object to be treated can be lowered (temperature lowered) more quickly. As a result, the time required for the heat treatment of the object to be treated can be shortened, and the production efficiency of the object to be processed can be further increased.

According to the present invention, in a vertical heat treatment apparatus, heat dissipation from the opening on the bottom side of the container is suppressed, heat unevenness in the horizontal direction in the bottom zone is reduced, and manufacturing cost and operation cost of the heat treatment apparatus are reduced. In addition, it is possible to secure a state in which the heat soaking property of the object to be treated is high regardless of the heat treatment conditions.

FIG. 1 is a schematic front view of a heat treatment apparatus according to an embodiment of the present invention, and a part thereof is shown in a cross section. FIG. 2 is a schematic side view of the heat treatment apparatus, and a part thereof is shown in cross section. FIG. 3 is a plan view of a main part of the heat treatment apparatus, and a part thereof is shown in cross section. FIG. 4 is an enlarged view showing a main part of FIG. 1. FIG. 5 is an enlarged view showing a main part of FIG. 2. FIG. 6 is a block diagram for explaining a main part of the configuration relating to the control of the heat treatment apparatus. FIG. 7 is a flowchart showing an example of the heat treatment operation in the heat treatment apparatus.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

FIG. 1 is a schematic front view of the heat treatment apparatus 1 according to the embodiment of the present invention, and a part thereof is shown in a cross section. FIG. 2 is a schematic side view of the heat treatment apparatus 1, and a part thereof is shown in cross section. FIG. 3 is a plan view of a main part of the heat treatment apparatus 1, and a part thereof is shown in cross section. FIG. 4 is an enlarged view showing a main part of FIG. 1. FIG. 5 is an enlarged view showing a main part of FIG. 2. In the present embodiment, the heat treatment apparatus 1 is viewed from the front as a reference, and refers to the vertical direction, the horizontal direction, and the front-rear direction.

With reference to FIGS. 1 to 3, the heat treatment apparatus 1 is configured to be able to heat-treat the surface of the object to be treated 100. More specifically, the heat treatment apparatus 1 is configured to be able to heat-treat the surface of the object to be treated 100 by supplying a heated gas (gas for heat treatment) toward the object to be treated 100. There is. As the heat treatment gas supplied here, for example, Air, O ₂ , N _{2, and the} like are used. In the present embodiment, the heat treatment apparatus 1 is a vertical furnace. In the present embodiment, the atmospheric temperature in the furnace at the time of heat treatment in the heat treatment apparatus 1 is about 200 ° C. to 500 ° C. The temperature of the atmosphere in the furnace during the heat treatment is not limited to the above-mentioned temperature.

In the present embodiment, the object to be treated 100 is a transparent glass substrate and is formed in a rectangular shape. In the present embodiment, the object to be processed 100 is a rectangular substrate whose length in the front-rear direction is larger than the length in the left-right direction. The object to be treated 100 may be square or may have a curved edge. Although the thickness of the object to be treated 100 is not particularly limited, a thickness of 0.2 mm to 1.2 mm can be exemplified. As a heat treatment performed on the object 100 to be processed by the heat treatment apparatus 1, a process of thermally curing the resin coated on the glass substrate can be exemplified. The heat treatment apparatus 1 of the present embodiment is preferably used for heat treatment excluding heat treatment using a heat treatment gas accompanied by metal contamination and heat treatment in a film forming process. The object 100 to be treated is not limited to the glass substrate and may be another member, but is particularly suitable for heat treatment of the glass substrate.

The heat treatment apparatus 1 includes a housing 2 including a heater 22, a tube 3 as a vertical container installed in the housing 2, and a holding mechanism for holding the object to be processed 100 during heat treatment of the object to be processed 100. 4, the heat ray reflecting member 5 installed in the holding mechanism 4, the elevating mechanism 6 for raising and lowering the holding mechanism 4, and the heat ray reflecting member 5 provided in the holding mechanism 4 are displaced in the vertical direction with respect to the holding mechanism 4. It has a displacement mechanism 7, a temperature sensor unit 8, and a control unit 9.

The housing 2 is formed in a box shape in which the lower portion is open downward.

The housing 2 has a pedestal 21, a heater 22 mounted on the pedestal 21, and a top wall 23 covering the upper part of the heater 22.

The pedestal 21 includes, for example, a horizontally extending plate-shaped portion.

The heater 22 is provided to heat the atmosphere in the tube 3 and the object to be processed 100. The heater 22 is formed in a cylindrical shape in a plan view, and in the present embodiment, it is formed in a rectangular tubular shape in a plan view. The heater 22 is arranged around the tube 3 and surrounds the quartz tube body 31 described later in the tube 3. The heater 22 is a heater including, for example, a heat insulating material containing a ceramic fiber and a heating element including a metal wire formed in a meandering shape and embedded in the heat insulating material. The heater 22 is divided into a plurality of areas (three areas in the present embodiment) in the vertical direction, and the output (surface temperature) can be changed for each area.

The heater 22 includes a bottom heater 22a arranged so as to surround the heat ray reflecting member 5, a center heater 22b arranged above the bottom heater 22a and arranged so as to surround the support portion 51 described later, and a center heater 22b. It has a top heater 22c arranged above the above.

The bottom heater 22a is installed in the bottom zone Za. The bottom zone Za is formed in the lower part of the housing 2 at the time of heat treatment, and is defined in the present embodiment over a height of about 1/3 of the height of the heater 22. In the present embodiment, the lower end 24 of the bottom heater 22a is arranged at the lower end of the bottom zone Za, and the upper end of the bottom heater 22a is arranged at the upper end of the bottom zone Za. The bottom heater 22a is mounted on the pedestal 21. The bottom heater 22a radiates heat toward the space in the bottom zone Za. A center heater 22b is mounted on the bottom heater 22a.

The center heater 22b is installed in the center zone Zb. The center zone Zb is formed in the middle portion of the housing 2 at the time of heat treatment, and is defined in the present embodiment over a height of about ½ of the height of the heater 22. In the present embodiment, the lower end of the center heater 22b is arranged at the lower end of the center zone Zb, and the upper end of the center heater 22b is arranged at the upper end of the center zone Zb. The center heater 22b radiates heat toward the space in the center zone Zb. The top heater 22c is mounted on the center heater 22b.

The top heater 22c is installed in the top zone Zc. The top zone Zc is formed on the upper part of the housing 2 at the time of heat treatment. In the present embodiment, the lower end of the top heater 22c is arranged at the lower end of the top zone Zc, and the upper end of the top heater 22c is arranged at the upper end of the top zone Zc. The top heater 22c radiates heat toward the space in the top zone Zc. The upper part of the top heater 22c is covered from above by the top wall 23 of the housing 2.

In the present embodiment, when the heater 22 is in operation, the temperature of the inner peripheral surface of the heater 22 is different for each zone. Specifically, when the heater 22 is in operation (during heat treatment of the object 100 to be processed), the temperature of the inner peripheral surface of the bottom heater 22a is higher than the temperature of the inner peripheral surface of the center heater 22b. Further, the temperature of the inner peripheral surface of the center heater 22b is higher than the temperature of the inner peripheral surface of the top heater 22c. That is, the temperature of the bottom heater 22a> the temperature of the center heater 22b> the temperature of the top heater 22c. In this way, in order to make the temperature inside the tube 3 uniform, it is possible to make the surface temperatures of the bottom heater 22a, the center heater 22b, and the top heater 22c different from each other. As a result, the temperature drop of the bottom zone Za due to heat radiation from the opening 34 of the tube 3 is suppressed.

A temperature sensor unit 8 is attached to the heater 22 having the above configuration.

The temperature sensor unit 8 includes a bottom sensor 8a for measuring the heater temperature of the bottom heater 22a, a center sensor 8b for measuring the heater temperature of the center heater 22b, a top sensor 8c for measuring the temperature of the heater of the top heater 22c, and a control point. It has a control point sensor 8d that measures the temperature inside the tube 3 at Cp.

In the present embodiment, the bottom sensor 8a is attached to the bottom heater 22a, and the tip of the bottom sensor 8a is arranged outside the tube 3 in the housing 2. In the present embodiment, the center sensor 8b is attached to the center heater 22b, and the tip of the center sensor 8b is arranged inside the housing 2 and outside the tube 3. In the present embodiment, the top sensor 8c is attached to the top heater 22c, and the tip of the top sensor 8c is arranged outside the tube 3 in the housing 2.

The control point sensor 8d is provided to detect the ambient temperature of the lowermost object to be processed 100. In the present embodiment, the control point sensor 8d detects the temperature in the region between the lowermost object 100 to be processed and the heat ray reflecting member 5 in the vertical direction. The control point sensor 8d is arranged in a region (center zone Zb) surrounded by the center heater 22b.

The control point sensor 8d measures the temperature at the control point Cp set near the lower part of the center zone Zb. It is preferable that the height position where the control point sensor 8d is installed is aligned with the height position of the control point Cp. The control point Cp is a point used to set the position (height position) of the heat ray reflecting member 5 in the vertical direction. The control point Cp is, for example, a center point in the tube 3 in a plan view at the height position of the third slot from the bottom among the plurality of support portions 51 described later of the holding mechanism 4. The position of the control point Cp is not limited to the above example. As the control point Cp, for example, any of the regions in the lower half of the center zone Zb may be set. The control point Cp is preferably set at the center of the space in the tube 3 in a plan view.

Each sensor 8a-8d is a thermocouple and detects the respective temperatures of the corresponding heaters 22a-22c and the control point Cp.

The tube 3 is a vertical container in which an opening 34 for taking in and out the object to be processed 100 is arranged at the lower end portion, and the upper end thereof is closed. In the present embodiment, the tube 3 is formed in a polygonal shape (rectangular shape) in a plan view. The tube 3 may be formed in a polygonal shape other than a rectangle in a plan view, or may be formed in a circular shape.

The tube 3 has a quartz tube body 31 and an annular tube holder 33 including a flange portion 32 that supports the lower end of the tube body 31.

The tube body 31 is formed in a cylindrical shape, has an opening facing downward, and has an upper end closed. The tube body 31 is surrounded by a heater 22. The tube body 31 is arranged in the bottom zone Za, the center zone Zb, and the top zone Zc. The upper end of the tube body 31 is arranged in the top zone Zc and faces the top wall 23 with a gap. The lower end of the tube body 31 is arranged on the lower end side of the bottom zone Za. The lower end of the tube body 31 is mounted on the annular flange portion 32. The outer peripheral portion of the flange portion 32 is fixed to the pedestal 21 of the housing 2.

The tube holder 33 cooperates with the tube body 31 to form a tubular tube 3. The tube holder 33 is formed in a cylindrical shape and has a height lower than the height of the tube main body 31. The tube holder 33 is arranged below the bottom zone Za and is not surrounded by the heater 22 in this embodiment. The lower end of the tube holder 33 is the opening 34 of the tube 3. A holding mechanism 4 is provided so as to be vertically movable with respect to the tube 3 having the above configuration.

The holding mechanism 4 has a closing lid 41, a heat barrier unit 42 provided on the closing lid 41, and a rack 43.

The closing lid 41 is provided as a lid for closing the opening 34. The opening 34 is formed in a disk shape, for example, and closes the opening 34 by coming into contact with the lower end of the tube holder 33. A sealing member such as an O-ring is interposed between the closing lid 41 and the lower end of the tube main body 31, so that the closing lid 41 and the tube main body 31 are sealed. The holding mechanism 4 including the closing lid 41 is raised and lowered by the elevating mechanism 6.

The elevating mechanism 6 raises and lowers the closing lid 41 to raise and lower the holding mechanism 4 and the object 100 supported by the support portion 51 of the holding mechanism 4. The elevating mechanism 6 has, for example, a movable portion 6a fixed to the closing lid 41 and a driving portion 6b for moving the movable portion 6a in the vertical direction using a power source such as an electric motor or fluid pressure. .. In the present embodiment, unless otherwise specified, the description will be based on the state in which the closing lid 41 closes the opening 34. A heat barrier unit 42 is installed on the closing lid 41.

The heat barrier unit 42 is provided to prevent heat in the tube 3 from escaping from the opening 34. The heat barrier unit 42 is located below the rack 43 in the tube 3 around the opening 34. In the present embodiment, the heat barrier unit 42 is installed between the closing lid 41 and the bottom zone Za.

With reference to FIGS. 1 to 5, the heat barrier unit 42 has a plurality of liner pins 44, a plurality of heat barriers 45 passed through the liner pins 44, and heat barriers 45 adjacent to each other in a state of being separated from each other. It has a spacer 46 for arranging.

The liner pins 44 are vertically elongated pins fixed to the closing lid 41 and are arranged apart from each other. The heat barrier 45 is a flat plate-shaped member formed by using a heat insulating material, and is arranged horizontally. As the material of the heat barrier 45, a neo-serum member can be exemplified. Neoserum has a low coefficient of thermal expansion and excellent thermal shock strength at high temperatures. In the present embodiment, a plurality (six) heat barriers 45 are formed by a plurality of neo-serum members arranged along the vertical direction. The number of heat barriers 45 may be other than six. Each heat barrier 45 is formed, for example, in the shape of a disk, and a through hole is formed at a position through which the liner pin 44 is passed. The spacer 46 is formed in a cylindrical shape and is fitted to any one of a plurality of liner pins 44. A plurality of spacers 46 are provided. The spacer 46 arranged on the lowermost side is installed on the closing lid 41 and receives the lowermost heat barrier 45 among the plurality of heat barriers 45. The second and subsequent spacers 46 from the bottom are arranged between the heat barriers 45 and 45 arranged in the vertical direction.

Racks 43 are arranged laterally and above the heat barrier unit 42 having the above configuration.

The rack 43 has a configuration in which a plurality of support portions 51 for supporting the edge portion 100a of the object to be processed 100 are provided vertically apart from each other, and holds the plurality of objects to be processed 100 in the tube 3. do. During the heat treatment, the rack 43 is arranged in the tube 3. The rack 43 arranges a plurality of objects 100 to be processed in a state of being separated in the vertical direction. In the present embodiment, the rack 43 arranges the object to be processed 100 in the center zone Zb. On the other hand, in the rack 43, the object to be processed 100 is not arranged in the bottom zone Za, while the heat ray reflecting member 5 is arranged. Further, the rack 43 does not arrange the object to be processed 100 in the top zone Zc.

The rack 43 has a plurality of columns 49 fixed to the closing lid 41, and a support portion 51 including a first stay 50 attached to each column 49.

The strut 49 extends upward from the obstruction lid 41. In this embodiment, for example, four columns 49 are provided.

The columns 49 extend in the vertical direction and are arranged over the bottom zone Za, the center zone Zb, and the top zone Zc. The support column 49 may not be arranged in the top zone Zc. In this embodiment, for example, four columns 49 are provided. Specifically, as is well shown in FIG. 3, the columns 49 are arranged near the four corners of the tube body 31.

With reference to FIGS. 1 to 5 again, the first stay 50 is provided to support the object to be processed 100 in the center zone Zb. The first stay 50 is formed in an elongated arm shape in the left-right direction, and is fixed to the corresponding support column 49 in a cantilevered state. A plurality of first stays 50 are provided in each column 49 at equal pitches in the vertical direction. The positions of the first stay 50 in the vertical direction are aligned between all the columns 49. In this way, the support portion 51 that horizontally supports one object to be processed 100 is formed by the four first stays 50 having the same height position. That is, the support portions 51 are provided as many as the number of the first stays 50 in the vertical direction. In the present embodiment, the object to be processed 100 is placed on each of the plurality of support portions 51 so as to be oriented in a plan view. Each support portion 51 is also referred to as a slot. The lowermost support portion 51 among the plurality of support portions 51 is referred to as a first slot, and the nth slot from the bottom is referred to as an nth slot. Note that n is a positive integer.

In the present embodiment, among the plurality of support portions 51, the region above the sixth slot, that is, the position higher than the lower end position of the bottom zone Za is set as the actual operation heat equalizing region Z1. The actual operation soaking area Z1 is an area treated as if there is no temperature difference in each object to be processed 100 when the temperature of the heater 22 is constant. The upper end position of the actual operation heat equalizing region Z1 is the height position of the second slot from the top in the present embodiment. The control point sensor 8d can be said to be a sensor that measures the temperature at the control point Cp set below the actual operation heat equalizing region Z1 in the center zone Zb.

Further, each first stay 50 is formed in an elongated shape as described above, so that the contact area with the object to be processed 100 is configured to be as small as possible. The lowermost first stay 50 (50a, first slot) among the plurality of first stays 50 is arranged in the lower part of the center zone Zb.

The displacement mechanism 7 displaces the heat ray reflecting member 5 in order to change the position of the heat ray reflecting member 5 with respect to the rack 43 in the vertical direction. In the present embodiment, the displacement mechanism 7 is provided so as to straddle the inside and the outside of the space in the tube 3. The entire displacement mechanism 7 may be arranged in the tube 3.

The displacement mechanism 7 includes, for example, a movable portion 71 that integrally supports the tray 53 in the vertical direction and a drive portion 72 that moves the movable portion 71 in the vertical direction using a power source such as an electric motor or fluid pressure. And have.

The drive unit 72 is fixed to, for example, the lower side surface of the closing lid 41. By arranging the drive unit 72 outside the tube 3 in this way, the amount of heat received by the drive unit 72 from inside the tube 3 can be reduced. The drive unit 72 supports the movable unit 71 so as to be relatively movable in the vertical direction.

The movable portion 71 extends in the vertical direction, and in the present embodiment, extends between the space inside the tube 3 and the space outside the tube 3.

The movable portion 71 has a shaft portion 73 extending in the vertical direction and receiving a force from the drive portion 72, and a second stay 74 arranged above the shaft portion 73 and in contact with the tray 53.

When the displacement mechanism 7 is a screw mechanism type, a male screw is formed in the shaft portion 73, and the male screw is screw-coupled to a nut member provided in the drive portion 72. In this case, the shaft portion 73 moves in the vertical direction as the nut member rotates. Further, in the shaft portion 73, when the displacement mechanism 7 is a rack and pinion type, rack teeth are formed, and the rack teeth mesh with the pinion teeth provided in the drive portion 72. In this case, the shaft portion 73 moves in the vertical direction as the pinion teeth rotate. In this way, the shaft portion 73 moves in the vertical direction by receiving the force from the drive portion 72. 1 and 4 show a state in which the movable portion 71 and the heat ray reflecting member 5 are moved in the vertical direction by a two-dot chain line which is an imaginary line. The shaft portion 73 extends into the space inside the tube 3 and the space outside the tube 3 through the through hole formed in the closing lid 41. A seal member (not shown) such as an O-ring is arranged between the through hole formed in the closing lid 41 and the shaft portion 73. Further, the shaft portion 73 penetrates through a through hole formed in each heat barrier 45.

The second stay 74 is provided to support the heat ray reflecting member 5 in the bottom zone Za. The second stay 74 has, for example, a plurality (three or more) axial portions extending upward from the shaft portion 73, and the upper ends of these axial portions are arranged apart from each other.

The tray 53 is a plate-shaped member made of heat-resistant glass or the like, and is received by the upper end of the second stay 74 and supported in a horizontal posture. The heat ray reflecting member 5 is placed on the tray 53.

Although an example of the displacement mechanism 7 has been described, the displacement mechanism 7 is not limited to the above-described configuration. The displacement mechanism 7 may have a configuration in which the position of the heat ray reflecting member 5 with respect to the rack 43 can be changed in the vertical direction.

The heat ray reflecting member 5 is arranged below the lowermost object to be processed 100 (in this embodiment, the object to be processed 100 at the lower end of the actual operation soaking area Z1) in the vertical direction, and the heat ray from the heater 22 is generated. Is provided to reflect on the object to be processed 100 supported by the rack 43. The heat ray reflecting member 5 reflects heat rays such as infrared rays toward the object to be processed 100 which is arranged on the lowermost side among the plurality of objects to be processed 100. In this embodiment, only one heat ray reflecting member 5 is provided. That is, one heat ray reflecting member 5 is installed in the tube 3.

The heat ray reflecting member 5 has a structure in which a metal film is coated on the surface of a rectangular glass. Examples of the material of the metal film include titanium, stainless steel, tin, and chromium. The heat ray reflecting member 5 is arranged in the bottom zone Za above the heat barrier 45.

In a plan view, it is preferable to arrange the heat ray reflecting member 5 and the object to be processed 100 so that the center C1 of the heat ray reflecting member 5 and the center C2 of the object 100 to be processed coincide with each other. Further, in a plan view (viewed from the vertical direction), it is preferable that the heat ray reflecting member 5 is arranged so as to avoid the four corners 100b of the object to be processed 100 supported by the support portion 51. In the arrangement example shown in FIG. 3, the heat ray reflecting member 5 is arranged so as to be entirely covered with the object to be processed 100 in a plan view.

With reference to FIG. 4, it is preferable that the heat ray reflecting member 5 (upper surface of the heat ray reflecting member 5) is arranged within the range of the bottom zone Za in the vertical direction. When the height position of the heat ray reflecting member 5 is lower than the lower end of the bottom zone Za, the heat rays from the heat ray reflecting member 5 are diffused over a wide range, and it becomes difficult to reach the lowermost object 100 to be processed. Further, when the height position of the heat ray reflecting member 5 is higher than the upper end of the bottom zone Za, the distance between the heat ray reflecting member 5 and the lowermost object 100 to be processed becomes too short, and the heat ray from the heat ray reflecting member 5 becomes too short. It is difficult to reach the lowermost object 100 evenly.

FIG. 6 is a block diagram for explaining a main part of the configuration relating to the control of the heat treatment apparatus 1. With reference to FIGS. 1 to 6, the control unit 9 is formed by using a PLC (Programmable Logic Controller) or the like. The control unit 9 may be formed by using a computer including a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), or may include an FPGA (Field Programmable Gate Array). It may be configured or may be formed by using a sequence circuit or the like. The control unit 9 is connected to a plurality of connection targets.

Specifically, the control unit 9 is connected to the bottom sensor 8a, the center sensor 8b, the top sensor 8c, and the control point sensor 8d of the temperature sensor unit 8, and the temperature detection results of these sensors 8a to 8d are obtained. Receive. The control unit 9 is connected to the bottom heater 22a, the center heater 22b, and the top heater 22c of the heater 22, and individually controls the outputs of these heaters 22a to 22c. The control unit 9 is connected to the drive unit 6b of the elevating mechanism 6 and controls the elevating operation of the movable unit 6a to control the elevating operation of the holding mechanism 4 and the object to be processed 100. The control unit 9 is connected to the drive unit 72 of the displacement mechanism 7, and controls the elevating operation of the movable unit 71 to control the elevating operation of the heat ray reflecting member 5. The control unit 9 (displacement mechanism 7) displaces the heat ray reflecting member 5 in the vertical direction based on the detected temperature detected by the control point sensor 8d.

The above is the schematic configuration of the heat treatment apparatus 1. Next, an example of the heat treatment operation in the heat treatment apparatus 1 will be described.

FIG. 7 is a flowchart showing an example of the heat treatment operation in the heat treatment apparatus 1. When the explanation is made with reference to the flowchart of FIG. 7, the drawings other than FIG. 7 are also referred to as appropriate.

Prior to the heat treatment operation in the heat treatment apparatus 1, the operation of setting the object to be processed 100 is performed. Specifically, the set operation is an operation in which the holding mechanism 4 including the rack 43 on which the object to be processed 100 is placed is raised by the raising operation of the raising / lowering mechanism 6 by the control unit 9. By this operation, the closing lid 41 closes the opening 43 of the tube 3. Further, the object to be processed 100 is arranged in the tube 3. The heat treatment operation is started from this state.

At the time of heat treatment, first, the control unit 9 supplies predetermined electric power to the heaters 22a to 22c of the heater 22. As a result, the control unit 9 heats each heater 22a to 22c so that the inner peripheral surfaces of the heaters 22a to 22c individually reach a predetermined target temperature (step S1).

At this time, that is, when the heater 22 raises the temperature inside the tube 3, the control unit 9 controls the drive unit 72 of the displacement mechanism 7 to make the heat ray reflecting member 5 have a predetermined high efficiency in the vertical direction. Place it at a position (step S2). The high efficiency position in this case means a position where the heat ray reflecting member 5 can reflect the heat ray from the heater 22 to the lowermost object 100 to be processed with relatively high efficiency. The specific reflection efficiency value of the heat ray by the heat ray reflecting member 5 is not limited.

When the temperature of the object to be processed 100 in the tube 3 is constant, the efficiency with which the heat ray reflecting member 5 reflects the heat rays from the heater 22 to the object to be processed 100 at the high efficiency reflection position is at the low efficiency reflection position described later. The heat ray reflecting member 5 is set higher than the efficiency of reflecting the heat ray from the heater 22 to the object to be processed 100. The efficiency in this case means, for example, the ratio of the amount of heat reflected by the heat ray reflecting member 5 to the object 100 to be processed with respect to the amount of heat received from the heater 22 by the heat ray reflecting member 5.

The high-efficiency position of the heat ray reflecting member 5 is preferably controlled by feedback control by the control unit 9. For example, a position control in which the position of the heat ray reflecting member 5 is set so that the deviation between the detection temperature of the center sensor 8b and the detection temperature of the control point sensor 8d becomes small can be exemplified.

The high-efficiency position of the heat ray reflecting member 5 in the vertical direction includes the shape and material of the object to be processed 100, the height position of the lowermost object to be processed 100 (which slot it is mounted on), and the heater 22. It depends on the target temperature of. Therefore, the control unit 9 may store a high-efficiency position according to the condition in the memory and control the height position of the heat ray reflecting member 5 based on the stored value.

The control unit 9 determines whether or not the temperature inside the tube 3 has reached a soaking state (step S3). Specifically, the control unit 9 refers to the temperature detection result of the control point sensor 8d and determines whether or not the temperature at the control point Cp is stable at a constant temperature. At this time, the control unit 9 samples the detection temperature of the control point sensor 8d for a while (for example, several seconds to several minutes), and determines whether or not the detection temperature does not substantially change. In addition, "substantially unchanged" means that the change in the detected temperature is, for example, within ± several ° C. While the heat is not equalized due to the change in the detection temperature of the control point sensor 8d (NO in step S3), the control unit 9 performs the process of step S2, that is, the position control of the heat ray reflecting member 5.

On the other hand, when the detection temperature of the control point sensor 8d is stable without substantially changing (YES in step S3), the control unit 9 determines whether or not to set the target temperature of the heater 22 even higher (step). S4). For example, the heating temperature of the object to be treated 100 may be raised in several steps from 350 ° C. to 450 ° C. to 500 ° C. In such a case, the control unit 9 sets the target temperature of the heater 22 even higher after a predetermined time has elapsed after the temperature in the tube 3 becomes a soaking state (YES in step S3). (YES in step S4). In this case, the control unit 9 repeats the processes of steps S1 to S3.

On the other hand, in step S4, when the target temperature of the heater 22 has already reached the maximum value or the target temperature of the heater 22 is one type, the control unit 9 lowers the temperature of the object to be processed 100. Whether or not it is determined (step S5). When maintaining a soaking state in which the object to be processed 100 has a constant temperature, the control unit 9 repeats the processes of steps S4 and S5 (NO in step S4 and NO in step S5).

On the other hand, when the temperature of the object to be processed 100 is lowered (YES in step S5), the control unit 9 sends the heater 22 to the heater 22 so as to lower the target temperature of each inner peripheral surface of the heaters 22a to 22c to a preset value. The electric power is controlled or the energization of the heater 22 is stopped (step S6).

At this time, that is, when the temperature inside the tube 3 (the temperature of the object to be processed 100) is being lowered, the control unit 9 controls the drive unit 72 of the displacement mechanism 7 to move the heat ray reflecting member 5 in the vertical direction. (Step S7). The low efficiency position in this case means a position where the heat ray reflecting member 5 is relatively difficult to reflect the heat ray from the heater 22 to the lowermost object 100 to be processed. In this case, the specific reflection efficiency value of the heat ray by the heat ray reflecting member 5 is not limited.

The low-efficiency position of the heat ray reflecting member 5 is preferably controlled by feedback control by the control unit 9. For example, a position control in which the position of the heat ray reflecting member 5 is set so that the deviation between the detection temperature of the center sensor 8b and the detection temperature of the control point sensor 8d becomes a predetermined value or more can be exemplified.

The low-efficiency position of the heat ray reflecting member 5 in the vertical direction includes the shape and material of the object to be processed 100, the height position of the lowermost object to be processed 100 (which slot it is mounted on), and the heater 22. It depends on the target temperature of. Therefore, the control unit 9 may store a low-efficiency position according to the condition in the memory and control the height position of the heat ray reflecting member 5 based on the stored value.

The control unit 9 determines whether or not the heat treatment of the object to be processed 100 is completed after completing the predetermined operation program (step S8). When the heat treatment of the object to be processed 100 is not completed (NO in step S8), the control unit 9 repeats the operations after step S6. On the other hand, when the control unit 9 determines that the heat treatment of the object to be processed 100 is completed after completing the predetermined operation program (YES in step S8), the control unit 9 stops the energization of the heater 22 and the heat ray by the displacement mechanism 7. The vertical position change operation of the reflective member 5 is stopped (step S9).

As described above, according to the present embodiment, the heat ray reflecting member 5 is arranged below the lowermost object 100 to be processed. The heat ray reflecting member 5 can reflect the heat rays from the heater 22 arranged around the tube 3 toward the object to be processed 100. As a result, heat dissipation from the opening 34 on the bottom side of the tube can be suppressed, and as a result, the temperature difference (difference between the maximum value and the minimum value of the temperature) in the object to be processed 100 arranged on the lowermost side can be suppressed. ) Can be made more even. That is, the heat equalizing function of the bottom zone as an area near the opening 34 on the bottom side of the tube 3 (less deviation of the temperature distribution in the horizontal direction) can be exhibited. Moreover, since a simple configuration in which the heat ray reflecting member 5 is installed is sufficient, it is not necessary to use a quartz box having a high manufacturing cost in order to suppress heat dissipation from the opening 34 on the bottom side of the tube 3, and the heat treatment apparatus 1 is manufactured. The cost can be reduced. Moreover, since the heat soaking property of the bottom zone can be increased without installing a sub-heater in the opening 34 on the bottom side of the tube 3, the manufacturing cost of the heat treatment apparatus 1 can be reduced and the operating cost such as electricity cost can be reduced. can. Further, the displacement mechanism 7 can change the vertical position of the heat ray reflecting member 5. Thereby, for example, the temperature difference in the object to be processed 100 can be made smaller according to the target temperature of the object to be processed 100 at the time of heat treatment and according to the attributes such as the size of the object to be processed 100. The heat ray reflecting member 5 can be arranged. Based on the above, in the vertical heat treatment apparatus 1, heat dissipation from the opening 34 on the bottom side of the tube 3 is suppressed, heat unevenness in the horizontal direction in the bottom zone Za is reduced, and further, the heat treatment apparatus 1 It is possible to reduce the manufacturing cost and the operating cost of the object 100, and it is possible to secure a state in which the heat soaking property of the object 100 to be treated is high regardless of the heat treatment conditions.

Further, according to the present embodiment, the displacement mechanism 7 can displace the heat ray reflecting member 5 in the vertical direction based on the detected temperature detected by the control point sensor 8d. According to this configuration, the heat ray reflecting member 5 can be arranged at a position where the heat ray from the heater 22 can be more evenly reflected to the object to be processed 100 by the feedback control according to the actual temperature in the tube 3. Therefore, the temperature difference in the object to be processed 100 can be made smaller.

Further, according to the present embodiment, the control point sensor 8d detects the temperature in the region between the lowermost object 100 to be processed and the heat ray reflecting member 5 in the vertical direction. According to this configuration, the control point sensor 8d can more accurately detect the heat generated by the heat rays from the heat ray reflecting member 5 toward the object to be processed 100. Therefore, the control unit 9 that controls the displacement mechanism 7 can arrange the heat ray reflecting member 5 at a more appropriate height position by using the detected temperature information. As a result, the temperature difference in the lowermost object to be processed 100 can be made smaller.

Further, according to the present embodiment, the control point sensor is located in the center zone Zb surrounded by the center heater 22b as a region where the sudden temperature change is relatively small because it is relatively far from the opening 34 where heat dissipation is likely to occur. 8d is arranged. As a result, the temperature detection result of the control point sensor 8d does not become unstable. Therefore, it is possible to prevent hunting from occurring in the position control of the heat ray reflecting member 5.

Further, according to the present embodiment, the control unit 9 arranges the heat ray reflecting member 5 at a high reflection efficiency position when the heater 22 raises the temperature inside the tube 3, and lowers the temperature inside the tube 3. Occasionally, the heat ray reflecting member 5 is arranged at a position with low reflection efficiency. According to this configuration, when the heater 22 raises the temperature in the tube 3, more heat rays from the heater 22 can be reflected from the heat ray reflecting member 5 to the object to be processed 100. Therefore, the temperature of the object to be processed 100 can be raised (temperature rise) more quickly. Further, when the temperature inside the tube 3 is lowered due to the completion of the heat treatment of the object to be processed 100 or the like, the heat ray reflecting member 5 can prevent the heat radiation from the object to be processed 100 from being disturbed. Therefore, the temperature of the object to be treated 100 can be lowered (temperature lowered) more quickly. As a result, the time required for the heat treatment of the object to be treated 100 can be shortened, and the production efficiency of the object to be processed 100 can be further increased.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. The present invention can be modified in various ways as described in the claims.

In the above-described embodiment, the control unit 9 operates the displacement mechanism 7 based on the temperature of the region between the lowermost object 100 to be processed and the heat ray reflecting member 5 in the vertical direction, whereby the heat ray reflecting member 5 is operated. Has been described as an example of displacing in the vertical direction. However, this does not have to be the case. The target for measuring the reference temperature for operating the displacement mechanism 7 may be the bottom zone Za or the center zone Zb.

The present invention can be widely applied as a heat treatment apparatus.

1 Heat treatment device 3 Tube (container)
5 Heat ray reflecting member 7 Displacement mechanism 8d Control point sensor (temperature sensor)
9 Control unit 22 Heater 22a Bottom heater 22b Center heater 34 Opening 43 Rack 45 Heat barrier 51 Support unit 100 Processed object Zb Center zone (area surrounded by center heater)

Claims (5)

A vertical container with an opening at the lower end for taking in and out the object to be processed,
The heaters placed around the container and
A rack having a configuration in which a plurality of support portions for supporting the object to be processed are provided vertically separated from each other and holding the plurality of objects to be processed in the container, and a rack.
A heat ray reflecting member arranged below the lowermost object to be processed in the vertical direction and reflecting heat rays from the heater to the object to be processed supported by the rack.
A displacement mechanism that displaces the heat ray reflecting member in order to change the position of the heat ray reflecting member with respect to the rack in the vertical direction.
Equipped with a heat treatment device. The heat treatment apparatus according to claim 1.
Further provided with a temperature sensor for detecting the temperature around the lowermost object to be processed.
The displacement mechanism is a heat treatment apparatus that displaces the heat ray reflecting member in the vertical direction based on the detected temperature detected by the temperature sensor. The heat treatment apparatus according to claim 2.
The temperature sensor is a heat treatment apparatus that detects the temperature of a region between the lowermost object to be processed and the heat ray reflecting member in the vertical direction. The heat treatment apparatus according to any one of claims 1 to 3.
The heater includes a bottom heater arranged so as to surround the heat ray reflecting member, and a center heater arranged above the bottom heater so as to surround each of the support portions and capable of having a temperature different from the temperature of the bottom heater. , Including
The temperature sensor is a heat treatment apparatus arranged in an area surrounded by the center heater. The heat treatment apparatus according to any one of claims 1 to 4.
Further provided with a control unit for controlling the displacement mechanism,
The control unit arranges the heat ray reflecting member at a predetermined high reflection efficiency position when the heater raises the temperature in the container, and causes the heat ray reflecting member when the temperature in the container is lowered. Place it in the specified low reflection efficiency position and
The efficiency with which the heat ray reflecting member reflects the heat ray from the heater to the object to be processed at the high efficiency reflection position is that the heat ray reflecting member reflects the heat ray from the heater to the object to be processed at the low efficiency reflection position. A heat treatment device that is set higher than the efficiency of reflection to.

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