JP5603055B2 - Hot plate and hot plate unit using the same - Google Patents

Description

  The present invention relates to a hot plate and a hot plate unit using the hot plate, and more particularly to a hot plate that heats a substrate to be heated in a horizontally mounted state and a technique for improving a hot plate unit using the hot plate.

  Conventionally, various heat treatments are performed in manufacturing processes of a semiconductor substrate, a glass substrate for a liquid crystal display device, a glass substrate for a plasma display device, a glass substrate for a photomask, a substrate for an optical disk, and the like. As an apparatus for performing such heat treatment, a heat treatment apparatus (hot plate unit) including a hot plate that heats a substrate to be heated as an object to be heated by heat conduction or heat radiation is used. In such a hot plate unit, the substrate to be heated is horizontally mounted on the mounting surface of the heat equalizing plate constituting the hot plate provided in the apparatus, and in such a state, the heating element is disposed inside the heat equalizing plate. By heating the soaking plate, the substrate to be heated is heated to a predetermined temperature.

  In the above-described hot plate, it is required that the substrate to be heated placed on the placement surface is heat treated at a uniform temperature over the entire surface during the heat treatment. Since the substrate to be heated is heated in a state where the substrate to be heated is horizontally mounted on a horizontal mounting surface formed on the heat plate, heat radiation (heat radiation) is performed between the outer peripheral portion and the center portion of the substrate to be heated. ) Differed, and it was difficult to heat the substrate to be heated while keeping the temperature constant. From this point of view, as disclosed in Patent Document 1, a ceramic for a semiconductor manufacturing apparatus in which a recess having a placement surface large enough to accommodate a substrate to be heated is formed on the surface of a ceramic substrate (soaking plate). The structure of the heater has been proposed.

  Certainly, according to the configuration of the hot plate disclosed in Patent Document 1 described above, heat radiation from the outer peripheral portion of the substrate to be heated is accommodated in the recess of the ceramic substrate (heat equalizing plate). It can be reduced, and it can be expected that the temperature uniformity of the substrate to be heated is improved by preventing the temperature of the outer peripheral portion from decreasing.

  However, in the hot plate, it is necessary to keep the mounting surface clean to prevent surface contamination of the substrate to be heated. However, like the hot plate disclosed in Patent Document 1, a ceramic substrate (a soaking plate) is used. In the configuration in which the concave portion is directly provided, fine dust (particles) such as airborne fine particles in the air and dust generated from the components of the hot plate easily accumulate on the bottom of the concave portion and the outer periphery of the bottom portion. Since the work is not easy, there is a problem that the maintainability is inferior. Furthermore, in order to form a predetermined recess on the surface of the ceramic substrate (heat equalizing plate), high processing accuracy is required, and the shape of the ceramic substrate (heat equalizing plate) is complicated, which increases the manufacturing cost of the hot plate. There was a problem.

Japanese Patent No. 3979264

  Accordingly, the present invention relates to a hot plate and a hot plate unit using the hot plate, which solves the above-described conventional problems, improves the heat uniformity of the substrate to be heated, and has a simple configuration and excellent maintainability. And a hot plate unit using the same.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

That is, in claim 1, in a hot plate that heats a substrate to be heated in a horizontal state, a heat equalizing plate having a horizontal surface on which the substrate to be heated is mounted and a straight line or a curve are repeated. And a partition plate formed by a member having a rectangular cross section extending along the outer peripheral surface of the substrate to be heated and detachably attached to the mounting surface of the heat equalizing plate. The partition plate is formed such that the inner peripheral surface faces the parallel position with respect to the outer peripheral surface of the substrate to be heated, and the length in the height direction is greater than the thickness of the substrate to be heated. The heating element is formed from a circuit pattern formed on the central portion side of the heat equalizing plate at a position vertically below the partition plate attached to the mounting surface of the heat equalizing plate. Circuit pattern formed outside in the circumferential direction Towards emissions are those that are densely formed close to each other.

According to a second aspect of the present invention, the partition plate is formed with a rectangular space portion in plan view surrounded by an inner peripheral surface, and the rectangular heated substrate is accommodated in the space portion.

According to a third aspect of the present invention, the partition plate is formed from the same metal material as the heat equalizing plate.

In claim 4 , the hot plate according to any one of claims 1 to 3 is used.

  As an effect of the present invention, the heat uniformity of the substrate to be heated can be improved, and the maintainability can be improved with a simple configuration.

The side view which showed typically the whole structure of the hotplate unit which concerns on one Example of this invention. The sectional side view which showed typically the structure of the hot plate of a present Example. The top view of a hotplate. FIG. 3 is an enlarged side sectional view of a part of the hot plate in FIG. 2. The top view of the hot plate of another Example.

  Next, embodiments of the invention will be described. In the following embodiments, a case where the hot plate unit 1 is configured as a heat treatment apparatus incorporated in a baking apparatus for manufacturing a photomask for baking a glass substrate for manufacturing a photomask with a predetermined temperature rise characteristic will be described. doing.

First, the overall configuration of the hot plate unit 1 of this embodiment will be outlined below.
As shown in FIGS. 1 to 3, the hot plate unit 1 of this embodiment is a heat treatment apparatus using a hot plate 2 that heats a glass substrate for manufacturing a photomask as a substrate to be heated S in a horizontal state. Specifically, the hot plate unit 1 includes, in addition to the hot plate 2, an elevating mechanism 3 that raises and lowers the substrate S to be heated, a reflector 4 that covers a space below the hot plate 2, and a hot plate 2 and a cover 5 covering the upper space.

  The substrate S to be heated is a glass substrate used for ordinary photomask manufacturing, and is generally a soda lime having a side of about 100 mm to 180 mm and a thickness of about 1.0 mm to 7.0 mm. A substrate or a quartz substrate is used. In order to manufacture a photomask using such a substrate to be heated S, a blank mask in which an inorganic thin film of metal, its oxide or nitride is formed on the substrate surface by a sputtering apparatus is created, and then on the blank mask A resist film is formed by coating, and a photomask having a predetermined pattern is manufactured by exposing the resist film to an electron beam.

  The hot plate 2 is disposed in a space surrounded by a casing (not shown) constituting the hot plate unit 1 and is supported by a plurality of (three in this embodiment) support members 10. And attached to the support base 11. One end of the support member 10 is fixed to the support base 11, and the other end is fixed to the bottom surface of the reflector 4. The hot plate 2 is fixed to the reflector 4 via a plurality of fixing members 12, 12. Is done. Thus, the hot plate 2 of this embodiment is attached to the support base 11 via the reflector 4 by the support member 10.

  The hot plate 2 according to the present embodiment includes a soaking plate 20 having a horizontal placement surface 20a on which the substrate to be heated S is placed, a heating element 21 disposed inside the soaking plate 20, and a soaking plate. It comprises a temperature sensor 22 that detects the surface temperature of the mounting surface 20a of the hot plate 20 and the like.

  As will be described later, the heat equalizing plate 20 includes an upper heat equalizing plate 23 and a lower heat equalizing plate 24, and the upper heat equalizing plate 23 and the lower heat equalizing plate 24 sandwich the heating element 21 as described above. The fixing member 12 is integrally assembled. The soaking plate 20 is formed in a circular shape in plan view, and a horizontal mounting surface 20a is formed on the upper surface. A plurality of (four in this embodiment) proximity pins 25, 25,... Protruding upward are disposed on the surface of the mounting surface 20a. The substrate S to be heated is the central portion of the placement surface 20a and is horizontally placed on the proximity pin 25 in a state of being close to the placement surface 20a.

  The heat equalizing plate 20 is provided with four through holes 20b, and through these through holes 20b, elevating pins 30 that support the heated substrate S and move up and down are penetrated. In the soaking plate 20 of the present embodiment, the drilling position of the through hole 20b is designed according to the size of the substrate to be heated S. Specifically, the substrate to be heated S is placed on the placement surface 20a. In this state, a through hole 20b is formed at a position where the tip 30a of the elevating pin 30 comes into contact with the outer peripheral portion of the substrate S to be heated.

  The heating element 21 is configured as a resistance heating element such as a sheathed heater, one end of which is connected to a power supply device (not shown), and is heated when energized by the power supply device. In the hot plate 2, the heating plate 21 is heated by the heating element 21, so that the heated substrate S is heated. As will be described later, the heating element 21 of the present embodiment is formed of a circuit pattern formed by repeating straight lines or curves so that the temperature of the mounting surface 20a and the substrate to be heated S is uniform. Heated.

  The temperature sensor 22 is attached to two locations below the soaking plate 20 and at the center portion of the placement surface 20a and the radially outer portion. Based on the surface temperature of the mounting surface 20a detected by the temperature sensor 22, the heating temperature of the heating element 21 is controlled through a control device (not shown) so that the surface temperature of the mounting surface 20a becomes a predetermined temperature. .

  The configuration of the hot plate 2 will be described later in detail.

  The elevating mechanism 3 includes a plurality of (four in this embodiment) elevating pins 30, 30... For elevating the heated substrate S, a support plate 31 that supports the elevating pins 30, the elevating pins 30 and the support. It is comprised with the raising / lowering apparatus 32 etc. which attach the board 31 to the support base 11 so that raising / lowering is possible. One end of the elevating pin 30 is fixed to a predetermined position of a support plate 31 having a rectangular shape in plan view, and the support plate 31 is connected to an elevating device 32 that is lateral to the support member 10 and fixed to the support base 11. . The lifting device 32 moves the support plate 31 up and down in the vertical direction using a lifting cylinder or the like.

  The operation of the lifting mechanism 3 will be described with reference to FIG. 2. When the heated substrate S is placed on the placement surface 20 a of the soaking plate 20, first, the support plate 31 is moved by the lifting device 32. Thus, the elevating pin 30 inserted through the through hole 20b of the heat equalizing plate 20 is moved up to a position protruding above the placement surface 20a of the heat equalizing plate 20. Next, the substrate to be heated S is placed on the tip portion 30a by a transfer device (not shown). In a state where the heated substrate S is supported by the elevating pins 30, the support plate 31 is moved downward by the elevating device 32, and the lower surface of the heated substrate S is brought into contact with the proximity pins 25 formed on the mounting surface 20a. In contact therewith, the heated substrate S is placed on the placement surface 20a. Even after the substrate to be heated S is placed on the placement surface 20 a, the support plate 31 is moved down by the lifting device 32, and the lifting pins 30 are accommodated in the through holes 20 b of the heat equalizing plate 20.

  In addition, when the substrate to be heated S is moved from the placement surface 20 a of the soaking plate 20, the support plate 31 is moved up by the elevating device 32 in reverse to the above-described operation. The heated substrate S is moved to the space above the soaking plate 20. When the heated substrate S on the tip portion 30a is taken out by a transfer device (not shown), the support plate 31 is moved down again, and the elevating pins 30 are accommodated in the through holes 20b of the soaking plate 20. The

  The reflector 4 is formed in a shape that surrounds the lower space and the side space of the heat equalizing plate 20 of the hot plate 2, and specifically, a plurality of plates that are formed in a substantially bowl shape and have different radial lengths. The shaped members are assembled so as to have a predetermined space area apart from each other. By configuring the reflector 4 in this way, heat loss due to radiation of the heat equalizing plate 20 is reduced, and the heat equalizing property of the hot plate 2 is improved.

  Similar to the reflector 4 described above, the cover 5 reduces heat loss due to radiation of the soaking plate 20 and is formed in a shape surrounding the space above the soaking plate 20 of the hot plate 2. The cover 5 of this embodiment is disposed so as to be movable up and down with respect to the hot plate 2, and when the substrate to be heated S is placed on the placement surface 20 a of the soaking plate 20, When the mounting surface 20a is moved up to a position where the mounting surface 20a is opened and the substrate S to be heated is heat-treated by the hot plate 2, the mounting surface 20a is moved down to a position where the mounting surface 20a of the soaking plate 20 is covered.

Next, the configuration of the hot plate 2 will be described in detail below.
As shown in FIGS. 2 to 4, the hot plate 2 of the present embodiment includes heat radiation from the outer peripheral portion of the substrate S to be heated in addition to the soaking plate 20, the heating element 21, the temperature sensor 22, and the like. The partition plate 26 for reducing the temperature and preventing the temperature drop at the outer peripheral portion and improving the heat uniformity of the substrate S to be heated is detachably provided.

  In the heat equalizing plate 20 of the present embodiment, the upper heat equalizing plate 23 having the mounting surface 20a formed on the upper surface and the lower heat equalizing plate 24 attached to the lower surface of the upper heat equalizing plate 23 are the fixing member 12 described above. Are integrally assembled with each other. Specifically, a mounting hole 20 c that penetrates the lower heat equalizing plate 24 and is opened on the lower surface of the upper heat equalizing plate 23 is formed in the outer periphery of the upper heat equalizing plate 23 and the lower heat equalizing plate 24. The fixing member 12 is inserted into the mounting hole 20c, so that the upper soaking plate 23 and the lower soaking plate 24 are assembled.

  The upper soaking plate 23 and the lower soaking plate 24 are formed of inconel, aluminum, hastelloy, stainless steel, or the like, which is a high-temperature heat-resistant metal material. Preferably, a ceramic layer of carbide ceramics (silicon carbide, titanium carbide, etc.), nitride ceramics (aluminum nitride, silicon nitride, etc.), oxide ceramics (alumina, silica, zirconia, etc.) is spray-coated on the metal material described above. Things are used. Thus, by forming the soaking plate 20 (the upper soaking plate 23 and the lower soaking plate 24) from a metal material, the processing performance is excellent as compared with a ceramic material, and the soaking plate 20 is cracked by high-temperature heating. And damage can be suppressed.

  On the upper surface of the lower heat equalizing plate 24, heating elements 21 made of a circuit pattern formed by repeating straight lines or curves are provided in a predetermined arrangement. Is placed, the heating element 21 is embedded in the upper and lower soaking plates 20 and 22. With this arrangement, the upper soaking plate 24 is heated by the heat generated by the heating element 21, and the heated substrate S is soaked up to a predetermined temperature via the placement surface 20a.

  The heating element 21 is formed by a circuit pattern that prevents the occurrence of hot spots, cold spots, etc. on the surface of the mounting surface 20a and heats the substrate S to be heated uniformly. The heating element 21 of the present embodiment is formed of a circuit pattern that is substantially concentrically continuous, and the center of the placement surface 20a is more than the circuit pattern disposed at the center of the placement surface 20a of the heat equalizing plate 20. The circuit pattern disposed on the outer side in the circumferential direction with respect to the portion is formed so as to be denser. Specifically, as compared with the circuit pattern 21a disposed in the central portion of the mounting surface 20a, the circuit pattern 21b disposed in the intermediate portion on the outer side in the circumferential direction and the outer peripheral portion of the mounting surface 20a. The provided circuit patterns 21c are formed so as to be close to each other and dense. Further, the circuit pattern 21c is formed to be denser than the circuit pattern 21b (see FIG. 4).

  The partition plate 26 is formed from a member having a rectangular cross section extending along the outer peripheral surface of the substrate to be heated S, and is formed from one member formed in a square shape in plan view. The partition plate 26 is detachably attached to a predetermined position of the placement surface 20a by a fixing bolt 27, and protrudes in the vertical direction with respect to the placement surface 20a of the heat equalizing plate 20. Specifically, the partition plate 26 has bolt holes 26a drilled at a total of four positions in the center of each side, and the bolt holes 26a are in contact with the placement surface 20a of the heat equalizing plate 20. It is fixed by a fixing bolt 27 via The partition plate 26 is easily attached to and detached from the heat equalizing plate 20 by inserting and removing the fixing bolt 27 into and from the bolt hole 26a.

  The partition plate 26 has an inner peripheral surface 26b as a continuous surface formed in a central direction, and a space portion 26c having a rectangular shape (square shape in this embodiment) in a plan view surrounded by the inner peripheral surface 26b is formed. Yes. The space portion 26c formed by the inner peripheral surface 26b has the same shape as the substrate to be heated S and is formed to be slightly larger than the substrate to be heated S. With such a shape, the partition plate 26 attached to the soaking plate 20 can form an accommodation space for the heated substrate S on the placement surface 20a of the soaking plate 20, and the heated substrate S Are accommodated in the space 26c of the partition plate 26 and placed on the placement surface 20a in a state of being surrounded by the partition plate 26 on the side.

  The partition plate 26 according to the present embodiment is formed so that the inner side surface 26b faces the parallel position with respect to the outer peripheral surface of the substrate to be heated S. In other words, the outer peripheral surface of the substrate to be heated S and the placement surface 20a. Therefore, the inner surface 26b of the partition plate 26 is also formed so that the angle formed with the mounting surface 20a is substantially a right angle. The partition plate 26 is formed so that the inner peripheral surface 26b of the partition plate 26 and the outer peripheral surface of the substrate to be heated S have a predetermined distance D. In a state where the substrate to be heated S is accommodated in the space portion 26c, it is preferable that the inner peripheral surface 26b of the partition plate 26 and the outer peripheral surface of the substrate to be heated S be as close as possible. And a predetermined separation D is set in consideration of the clearance and the like.

  The partition plate 26 is formed so that the length H in the height direction is longer than the thickness of the substrate to be heated S, and the substrate to be heated S in a state where the substrate to be heated S is placed on the placement surface 20a. The partition plate 26 is formed so as to protrude upward from the upper surface. In this way, the substrate to be heated S is placed on the placement surface 20a by the partition plate 26 in a state of being surrounded not only from the circumferential direction but also from the upper direction at the outer peripheral portion.

  As a mounting position of the partition plate 26, it arrange | positions so that it may be located in the intermediate part vicinity of the circumferential direction outer side rather than the center part of the mounting surface 20a. The mounting position of the partition plate 26 is an upper position of the heating element 21 formed of the circuit pattern densely arranged as described above. In other words, the partition plate 26 is a circuit pattern at the center of the heating element 21. The circuit pattern 21b and the circuit pattern 21c are arranged at a higher position than the circuit pattern 21a.

  As described above, the hot plate 2 according to the present embodiment has the horizontal mounting surface 20a on which the heated substrate S is mounted in the hot plate 2 that heats the heated substrate S in a horizontally mounted state. The heat equalizing plate 20, a heating element 21 having a circuit pattern formed by repeating a straight line or a curve, and a member having a rectangular cross section extending along the outer peripheral surface of the substrate to be heated S, are formed. And a partition plate 26 that is detachably attached to the mounting surface 20a. The partition plate 26 has an inner peripheral surface 26b opposed to the outer peripheral surface of the substrate to be heated S in a parallel position. Since it is formed and the length H in the height direction is longer than the thickness of the substrate to be heated S, the heat uniformity of the substrate to be heated S can be improved and the maintainability can be improved with a simple configuration. is there.

  That is, the hot plate 2 of the present embodiment is provided with a partition plate 26 formed of a member having a rectangular cross section extending along the outer peripheral surface of the substrate S to be heated. The surface 26b is formed so as to be opposed to the outer peripheral surface of the substrate to be heated S in a parallel position, and the height direction length H is formed to be longer than the thickness of the substrate to be heated S. By surrounding the outer peripheral portion of the substrate to be heated S not only from the circumferential direction but also from the upper direction by the partition plate 26, it is possible to effectively reduce the heat radiation from the outer peripheral portion of the substrate to be heated S. The temperature uniformity of the substrate to be heated S can be improved by preventing the temperature drop of the part.

  In particular, since the partition plate 26 of the present embodiment is detachably attached to the placement surface 20a of the soaking plate 20, the partition plate 26 is removed from the soaking plate 20 when the placement surface 20a is cleaned. Thus, such maintenance work can be easily performed. Therefore, by increasing the frequency of maintenance work, the mounting surface 20a is kept clean without depositing fine dust such as airborne particulates or dust generated from the components of the hot plate 2 on the mounting surface 20a. Thus, surface contamination of the substrate to be heated S can be easily prevented.

  Moreover, the hot plate 2 of the present embodiment is more circumferential with respect to the central portion of the mounting surface 20a than the circuit pattern 21a in which the heating element 21 is disposed at the central portion of the mounting surface 20a of the soaking plate 20. The circuit patterns 21b and 21c disposed on the outer side are formed more densely, and the partition plate 26 is configured to be attached to a position above the heating element 21 including the circuit patterns 21b and 21c disposed densely. Therefore, the heat storage of the heat equalizing plate 20 heated by the heating element 21 can be effectively transmitted to the partition plate 26 by heat conduction, and the heat radiation from the outer peripheral portion of the substrate S to be heated is reduced, and the outer periphery. The temperature drop of the part can be effectively prevented.

  In addition, a space portion 26c having a rectangular shape in plan view is formed in which the partition plate 26 is surrounded by the inner peripheral surface 26b, and a rectangular heated substrate S (a glass substrate as a photomask substrate) is accommodated in the space portion 26c. For this reason, in the rectangular substrate to be heated S, it is possible to effectively prevent a temperature drop at the corners of the outer peripheral portion where heat radiation is particularly large.

  Furthermore, since the partition plate 26 is formed of the same metal material as the soaking plate 20, it is easy to process and can prevent cracks and breakage due to high-temperature heating.

  As described above, the configurations of the hot plate unit 1 and the hot plate 2 of the present embodiment are not limited to the above-described embodiments, and various modifications can be made without departing from the object of the present invention.

  That is, the hot plate unit 1 of the above-described embodiment is configured as a heat treatment apparatus that heat-treats a glass substrate for a photomask as the substrate to be heated S. However, the apparatus configuration is not limited to this, and for example, The heating substrate S can be applied to a heat treatment apparatus for heat-treating a semiconductor substrate (wafer), a glass substrate for a liquid crystal display device, a substrate for an optical disk, or the like. In addition, such an apparatus configuration may be configured such that heat treatment can be performed not only in the atmosphere but also in a vacuum.

  The hot plate 2 of the above-described embodiment is configured to heat a glass substrate having a rectangular shape in plan view as the substrate to be heated S. In such a configuration, at least corners of the substrate to be heated S having a rectangular shape are used. It may be configured by a plurality of partition plates 126, 126,... Formed so as to cover the opposing position of the outer peripheral surface of the corner from the side. For example, like a partition plate 126 shown in FIG. 5, a plurality of (in a plan view L-shape formed from members having a rectangular cross section extending along the corners of the outer peripheral surface of the substrate S to be heated. In this embodiment, it may be formed of four members. Each of the partition plates 126, 126,... Has a rectangular shape (in this embodiment, a square shape) in which the space portion 126c surrounded by the inner peripheral surface 126b is oriented so that the inner peripheral surface 126b as a continuous surface faces the center. It is arrange | positioned so that it may become. As described above, by configuring the partition plate 126, it is possible to effectively prevent a temperature drop at the corners of the outer peripheral portion where heat radiation is particularly large.

  Further, in the hot plate 2 of the above-described embodiment, the partition plate 26 is configured such that the distance D between the inner peripheral surface 26b and the outer peripheral surface of the substrate to be heated S and the length H in the height direction are uniformly formed. However, the distance D and the length H in the height direction are changed only at predetermined locations facing the outer peripheral portion of the substrate to be heated S according to the heating conditions of the soaking plate 20 and the substrate to be heated S, respectively. May be formed.

  Furthermore, as the shape of the partition plate 26, a space portion 26c capable of accommodating the substrate to be heated S may be formed. For example, the space plate 26c capable of accommodating the substrate to be heated S is left, and the soaking plate 20 is mounted. It is good also as a shape which covers all the other locations of the mounting surface 20a. In such a case, the attachment position of the partition plate 26 is disposed so as to cover the circumferential outer side position other than the central portion of the placement surface 20a.

DESCRIPTION OF SYMBOLS 1 Hot plate unit 2 Hot plate 20 Soaking plate 20a Mounting surface 21 Heat generating body 23 Upper soaking plate 24 Lower soaking plate 26 Partition plate 26b Inner peripheral surface 26c Space S S Substrate

Claims (4)

In a hot plate that heats the substrate to be heated in a horizontal state,
A soaking plate having a horizontal mounting surface on which the substrate to be heated is mounted;
A heating element comprising a circuit pattern formed by repeating a straight line or a curve;
A partition plate formed from a member having a rectangular cross section extending along the outer peripheral surface of the substrate to be heated, and detachably attached to the mounting surface of the heat equalizing plate;
Comprising
The partition plate is formed such that the inner peripheral surface faces the parallel position with respect to the outer peripheral surface of the substrate to be heated, and the length in the height direction is longer than the thickness of the substrate to be heated. ,
The heating element is formed on the outer side in the circumferential direction with respect to a circuit pattern formed on the central portion side of the heat equalizing plate at a position vertically below the partition plate attached to the mounting surface of the heat equalizing plate. The circuit patterns are formed closer and closer together,
A hot plate characterized by that.   2. The hot plate according to claim 1, wherein the partition plate is formed with a rectangular space in plan view surrounded by an inner peripheral surface, and a rectangular heated substrate is accommodated in the space. .   The hot plate according to claim 1, wherein the partition plate is made of the same metal material as the heat equalizing plate.   A hot plate unit comprising the hot plate according to any one of claims 1 to 3.

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