heater

Abstract

This heater comprises: a substrate on which a heating object is placed; a tube body secured on a bottom surface of the substrate; a first plate on which a bottom end section of the tube body is secured; a second plate disposed below the first plate and secured to a mounting base; one or more seal members configured in an annular shape and sealing the space between a bottom surface of the first plate and a top surface of the second plate; three or more first screws that are joined to screw holes in the second plate or to screw holes in the first plate so as to press the bottom surface of the first plate or the top surface of the second plate; and three or more second screws that fasten the first plate and the second plate so as to pull the bottom surface of the first plate toward the top surface of the second plate.

Description

Technical Field

[0004] ,

[0001] The present disclosure relates to a heater. This application claims priority based on Japanese Patent Application No. 2023-010761 filed on January 27, 2023, and incorporates all the descriptions described in the Japanese application.

Background Art

[0002] Patent Document 1 discloses a film forming apparatus for forming a thin film on a wafer. The film forming apparatus includes a chamber, a shower head, and a heater. The shower head supplies gas into the chamber. The shower head is provided on the ceiling wall of the chamber. The heater heats the wafer to be heated. The heater includes a disk-shaped susceptor, a cylindrical support for supporting the susceptor, and a mounting plate to which the lower end of the support is fixed. The susceptor is a substrate having an upper surface on which the wafer is placed and a lower surface opposite to the upper surface. In the chamber, the shower head and the upper surface face each other.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] The heater of this disclosure comprises a base on which an object to be heated is placed; a cylindrical body fixed to the lower surface of the base; a first plate to which the lower end of the cylindrical body is fixed; a second plate positioned below the first plate and fixed to a mounting base; one or more sealing members configured in an annular shape to seal the space between the lower surface of the first plate and the upper surface of the second plate; three or more first screws coupled to the screw holes of the second plate or the screw holes of the first plate so as to press against the lower surface of the first plate or the upper surface of the second plate; and three or more second screws fastening the first plate and the second plate together so as to pull the lower surface of the first plate towards the upper surface of the second plate. [Brief explanation of the drawing]

[0005] [Figure 1] Figure 1 is a schematic diagram showing a first example of the heater of Embodiment 1. [Figure 2] Figure 2 is a schematic diagram showing a second example of the heater of Embodiment 1. [Figure 3] Figure 3 is a schematic diagram showing a third example of the heater of Embodiment 1. [Figure 4] Figure 4 is a schematic diagram showing a fourth example of the heater of Embodiment 1. [Figure 5] Figure 5 is a schematic diagram showing a fifth example of the heater of Embodiment 1. [Figure 6] Figure 6 is an enlarged schematic diagram showing the first example of region A in Figure 1. [Figure 7] Figure 7 is an enlarged schematic diagram showing a second example of region A in Figure 1. [Figure 8] Figure 8 is a schematic diagram showing a first example of the arrangement of the first and second screws in the heater of Embodiment 1. [Figure 9] Figure 9 is a schematic diagram showing a second example of the arrangement of the first and second screws in the heater of Embodiment 1. [Figure 10] Figure 10 is a schematic diagram showing a third example of the arrangement of the first and second screws in the heater of Embodiment 1. [Figure 11]Figure 11 is a schematic diagram showing a fourth example of the arrangement of the first and second screws in the heater of Embodiment 1. [Figure 12] Figure 12 is a schematic diagram showing a fifth example of the arrangement of the first and second screws in the heater of Embodiment 1. [Figure 13] Figure 13 is a schematic diagram showing a sixth example of the arrangement of the first and second screws in the heater of Embodiment 1. [Figure 14] Figure 14 is a schematic diagram showing a seventh example of the arrangement of the first and second screws in the heater of Embodiment 1. [Figure 15] Figure 15 is a schematic diagram showing an eighth example of the arrangement of the first and second screws in the heater of Embodiment 1. [Figure 16] Figure 16 is a schematic diagram showing a ninth example of the arrangement of the first and second screws in the heater of Embodiment 1. [Figure 17] Figure 17 is a schematic diagram showing a tenth example of the arrangement of the first and second screws in the heater of Embodiment 1. [Figure 18] Figure 18 is a schematic diagram showing an eleventh example of the arrangement of the first and second screws in the heater of Embodiment 1. [Figure 19] Figure 19 is a schematic diagram showing a twelfth example of the arrangement of the first and second screws in the heater of Embodiment 1. [Figure 20] Figure 20 is a schematic diagram showing a thirteenth example of the arrangement of the first and second screws in the heater of Embodiment 1. [Figure 21] Figure 21 is a schematic diagram showing the heater of Embodiment 2. [Figure 22] Figure 22 is a schematic diagram showing the arrangement of the first screw, second screw, and third screw provided in the heater of Embodiment 2. [Figure 23] Figure 23 is a schematic diagram showing a first example of the heater of Embodiment 3. [Figure 24] Figure 24 is a schematic diagram showing a second example of the heater of Embodiment 3.

Best Mode for Carrying Out the Invention

[0006] [Problems to be Solved by the Present Disclosure] When the mounting plate is fixed to a mounting base or the like such that the shower head faces the upper surface of the substrate, the distance between the shower head and the upper surface of the substrate may become non-uniform due to dimensional tolerances of each member. If the above distance is non-uniform, a thin film of uniform thickness cannot be formed on the surface of the wafer.

[0007] One object of the present disclosure is to provide a heater that can make the distance between the shower head and the upper surface of the substrate uniform.

[0008] [Effects of the Present Disclosure] The heater of the present disclosure can make the distance between the shower head and the upper surface of the substrate uniform.

[0009] 《Description of Embodiments of the Present Disclosure》 First, embodiments of the present disclosure will be listed and described.

[0010] (1) The heater according to one aspect of the present disclosure includes a substrate on which a heating target is placed, a cylindrical body fixed to the lower surface of the substrate, a first plate to which the lower end portion of the cylindrical body is fixed, a second plate disposed below the first plate and fixed to a mounting base, one or more seal members configured in an annular shape to seal between the lower surface of the first plate and the upper surface of the second plate, three or more first screws coupled to a screw hole of the second plate or a screw hole of the first plate so as to press the lower surface of the first plate or the upper surface of the second plate, and three or more second screws for fastening the first plate and the second plate so as to attract the lower surface of the first plate to the upper surface of the second plate.

[0011] The heater described in (1) above can make the gap between the shower head and the upper surface of the substrate uniform. This is because the heater described in (1) above can locally adjust the gap between the lower surface of the first plate and the upper surface of the second plate using three or more first screws and three or more second screws. In other words, with the heater described in (1) above, even if the gap between the shower head and the upper surface of the substrate of the film deposition apparatus becomes uneven when the heater is fixed to the mounting base, it can be corrected so that the gap between the shower head and the upper surface of the substrate becomes uniform. Therefore, the heater described in (1) above can be used to construct a film deposition apparatus that can form a thin film of uniform thickness on the surface of a wafer.

[0012] (2) In the heater described in (1) above, the lower surface of the first plate or the upper surface of the second plate may have annularly arranged first grooves and second grooves. The diameter of the second groove is greater than the diameter of the first groove. The depth of the first groove and the depth of the second groove are the same. The number of the one or more sealing members is two, consisting of a first sealing member and a second sealing member. The unloaded thickness of the second sealing member is greater than the unloaded thickness of the first sealing member. The first sealing member is located in the first groove. The second sealing member is located in the second groove.

[0013] In the heater described in (2) above, the second sealing member is positioned further from the center of the first plate than the first sealing member. When the heater is in use, the first and second sealing members are compressed by the first and second plates. When the first and second screws are operated to make the gap between the shower head and the top surface of the base uniform, there are areas where the gap between the bottom surface of the first plate and the top surface of the second plate gradually widens from areas closer to the center of the first plate to areas further away. If the depth of the first groove and the depth of the second groove are the same, and the thickness of the first sealing member and the thickness of the second sealing member are the same, then in the areas where the gap gradually widens, the second sealing member is less likely to be compressed by the first and second plates compared to the first sealing member. In the heater described in (2) above, although the depth of the first groove and the depth of the second groove are the same, the thickness of the second sealing member is greater than the thickness of the first sealing member. Therefore, even in areas where the gap gradually widens, the second sealing member is more easily compressed by the first and second plates compared to when it has the same thickness as the first sealing member. Consequently, gas is less likely to flow into the heater described in (2) above than into the second sealing member.

[0014] (3) In the heater described in (1) above, the lower surface of the first plate or the upper surface of the second plate may have annularly shaped first grooves and second grooves. The diameter of the second groove is greater than the diameter of the first groove. The depth of the second groove is shallower than the depth of the first groove. The number of the one or more sealing members is two, consisting of a first sealing member and a second sealing member. The unloaded thickness of the first sealing member and the unloaded thickness of the second sealing member are the same. The first sealing member is positioned in the first groove. The second sealing member is positioned in the second groove.

[0015] In the heater described in (3) above, even in areas where the aforementioned gap gradually widens, the second sealing member is more easily compressed by the first plate and the second plate compared to the case where the depth of the first groove and the depth of the second groove are the same. Therefore, in the heater described in (3) above, similar to the heater described in (2) above, gas is less likely to flow into the interior than through the second sealing member.

[0016] (4) In the heater described in (2) or (3) above, the first groove and the second groove may be provided concentrically.

[0017] In the heater described in (4) above, the length of the distance between the lower surface of the first plate and the upper surface of the second plate is more easily adjusted to be uniform compared to the case where the first groove and the second groove are not provided concentrically.

[0018] (5) In the heater described in (4) above, the center of the first groove and the center of the second groove may be the center of the envelope of the first plate or the center of the envelope of the second plate.

[0019] The heater described in (4) above makes it easier to adjust the length of the gap between the lower surface of the first plate and the upper surface of the second plate, compared to the case where the centers of the first groove and the second groove are located at different positions from the centers of the envelopes of the first plate and the second plate.

[0020] (6) In any of the heaters described in (1) to (5) above, the number of three or more first screws and the number of three or more second screws may be the same.

[0021] The heater described in (6) above has the same number of first and second screws, which makes it easier to create a uniform gap between the shower head and the top surface of the base.

[0022] (7) In any of the heaters described in (1) to (6) above, the three or more first screws may be arranged on the circumference of a first circle centered on the center of the envelope of the first plate, and the three or more second screws may be arranged on the circumference of a second circle centered on the center of the envelope of the first plate.

[0023] In the heater described in (7) above, the distance from the center of the envelope of the first plate to each first screw is uniform, and the distance from the center of the envelope of the first plate to each second screw is uniform. Therefore, the heater described in (7) above makes it easy to make the gap between the shower head and the upper surface of the base uniform.

[0024] (8) In the heater described in (7) above, the first circle and the second circle may be the same circle.

[0025] In the heater described in (8) above, the distance from the center of the envelope of the first plate to each first screw and the distance from the center of the envelope of the first plate to each second screw are uniform. Therefore, the heater described in (8) above makes it easy to make the gap between the shower head and the upper surface of the base uniform.

[0026] (9) In the heater described in (7) above, the first circle and the second circle may be concentric circles with different radii.

[0027] In the heater described in (9) above, although the distance from the center of the envelope of the first plate to each first screw and the distance from the center of the envelope of the first plate to each second screw are different, the distance from the center of the envelope of the first plate to each first screw is uniform, and the distance from the center of the envelope of the first plate to each second screw is uniform. Therefore, the heater described in (9) above makes it easy to make the gap between the shower head and the upper surface of the base uniform.

[0028] (10) In the heater described in (8) or (9) above, the three or more first screws may be arranged at equal intervals on the circumference of the first circle, and the three or more second screws may be arranged at equal intervals on the circumference of the second circle.

[0029] When the first circle and the second circle are the same circle, the heater (10) described above has uniform distances from the center of the envelope of the first plate to each first screw and from the center of the envelope of the first plate to each second screw, uniform spacing between adjacent first screws in the direction along the central axis, and uniform spacing between adjacent second screws in the direction along the central axis. Therefore, the heater (10) described above makes it easy to make the spacing between the shower head and the upper surface of the base uniform.

[0030] When the first and second circles are concentric circles with different radii, the heater (10) described above has a uniform distance from the center of the envelope of the first plate to each first screw, and a uniform spacing between adjacent first screws in the direction along the central axis. Furthermore, the heater (10) described above has a uniform distance from the center of the envelope of the first plate to each second screw, and a uniform spacing between adjacent second screws in the direction along the central axis. Therefore, although the heater (10) described above has different distances from the center of the envelope of the first plate to each first screw and different distances from the center of the envelope of the first plate to each second screw, it is easy to make the spacing between the shower head and the upper surface of the base uniform.

[0031] (11) In any of the heaters described in (7) to (10) above, three or more third screws may be further provided to restrict the distance between the lower surface of the first plate and the upper surface of the second plate to a predetermined value or less. The number of the three or more third screws is the same as the number of the three or more first screws and the number of the three or more second screws. Each of the three or more third screws has a head facing the upper surface of the first plate, a shaft portion that penetrates the first plate, and a male screw portion that is coupled to the second plate.

[0032] The heater described in (11) above can control the maximum distance between the lower surface of the first plate and the upper surface of the second plate using the third screw. This is because if the first plate is moved within a predetermined range away from the second plate, the upper surface of the first plate will come into contact with the head of the third screw, preventing the first plate from moving above the head. In other words, the heater described in (11) above can prevent the lower surface of the first plate from moving too far away from the upper surface of the second plate. Therefore, the heater described in (11) above can easily maintain a state in which the sealing member is compressed by the first plate and the second plate.

[0033] (12) In the heater described in (11) above, the three or more third screws may be arranged on the circumference of a third circle centered on the center of the envelope of the first plate.

[0034] In the heater described in (12) above, the distance from the center of the envelope of the first plate to each third screw is uniform. In other words, in the heater described in (12) above, the maximum distance between the lower surface of the first plate and the upper surface of the second plate tends to be uniform in the direction away from the center.

[0035] (13) In the heater described in (12) above, the third circle may be the same circle as at least one of the first circle and the second circle.

[0036] The heater described in (13) above makes it easy to control the maximum distance between the lower surface of the first plate and the upper surface of the second plate, and makes it easy to make the distance between the shower head and the upper surface of the base uniform.

[0037] (14) In the heater described in (12) or (13) above, the three or more third screws may be arranged at equal intervals on the circumference of the third circle.

[0038] In the heater described in (14) above, the distance from the center of the envelope of the first plate to each third screw is uniform, and the spacing between adjacent third screws is uniform in the direction along the central axis. In other words, in the heater described in (14) above, the maximum distance between the lower surface of the first plate and the upper surface of the second plate tends to be uniform in the direction along the central axis.

[0039] (15) Any heater described in (1) to (14) above may further include a pin sandwiched between the lower surface of the first plate or the upper surface of the second plate and each of the three or more first screws.

[0040] If a pin is not provided, when adjusting the gap between the lower surface of the first plate and the upper surface of the second plate, if the first screw rotates and directly touches the lower surface of the first plate or the upper surface of the second plate, there is a risk that the lower surface of the first plate or the upper surface of the second plate may be scraped. The heater described in (15) above is more effective in preventing the lower surface of the first plate or the upper surface of the second plate from being scraped by the rotating first screw because a pin is inserted into it.

[0041] (16) In the heater described in (15) above, the lower surface of the first plate or the upper surface of the second plate may have a recess in which the pin is arranged.

[0042] The heater described in (16) above can be configured to stably press the pin against the lower surface of the first plate or the upper surface of the second plate.

[0043] Details of the embodiments of this disclosure The details of the heater in this disclosure will be described below based on the drawings. The same reference numerals in the drawings indicate the same component. The dimensions of the components shown in each drawing are for illustrative purposes only and do not necessarily represent actual dimensional relationships.

[0044] Embodiment 1 〔heater〕 The heater 1 of Embodiment 1 will be described with reference to Figures 1 to 20. As shown in Figures 1 to 5, the heater 1 comprises a base 2, a cylindrical body 3, and a plate 4. The base 2 has an upper surface 2a and a lower surface 2b on which the object to be heated is placed. The object to be heated is, for example, a silicon or compound semiconductor wafer. The cylindrical body 3 supports the base 2. The upper end 31 of the cylindrical body 3 is fixed to the lower surface 2b. The lower end 32 of the cylindrical body 3 is fixed to the plate 4. The plate 4 is fixed to a mounting base 9. One of the features of the heater 1 of Embodiment 1 is that it satisfies the following requirements (A) to (C). (A) Plate 4 is composed of two plates, the first plate 41 and the second plate 42. (B) The heater 1 includes one or more sealing members 6 positioned between the first plate 41 and the second plate 42. (C) The heater 1 includes three or more first screws 51 and three or more second screws 52 that are provided to allow local adjustment of the distance between the lower surface 41b of the first plate 41 and the upper surface 42a of the second plate 42.

[0045] The heater 1 of Embodiment 1 can be used in a film deposition apparatus for forming a thin film on the surface of a wafer. In the film deposition apparatus, the heater 1 is fixed to a mounting base 9 such that the shower head and the upper surface 2a of the substrate 2 face each other in the chamber. The shower head supplies gas into the chamber. When the heater 1 is fixed to the mounting base 9, the distance between the upper surface 2a of the substrate 2 and the shower head may become uneven. If the above distance is uneven, a thin film of uniform thickness cannot be formed on the surface of the wafer. In the heater 1 of Embodiment 1, the distance between the lower surface 41b of the first plate 41 and the upper surface 42a of the second plate 42 can be locally adjusted by three or more first screws 51 and three or more second screws 52, which will be described in detail later. Therefore, the heater 1 of Embodiment 1 can make the distance between the shower head and the upper surface 2a of the substrate 2 uniform. In other words, in the heater 1 of Embodiment 1, even if the distance between the upper surface 2a of the base 2 and the shower head becomes uneven when the heater 1 is fixed to the mounting base 9, it is possible to correct the distance between the upper surface 2a of the base 2 and the shower head so that it becomes uniform. Therefore, the heater 1 of Embodiment 1 can be used to construct a film deposition apparatus that can form a thin film of uniform thickness on the surface of a wafer.

[0046] [Base] The base body 2 in this example has a disc shape. The base body 2 has an upper surface 2a and a lower surface 2b. A heating object (not shown) is placed on the upper surface 2a. The lower surface 2b is the opposite surface of the upper surface 2a. A cylindrical body 3, which will be described later, is attached to the lower surface 2b. The material of the base body 2 is, for example, ceramics. The ceramics are, for example, aluminum nitride, aluminum oxide, or silicon carbide. The base body 2 may also be composed of a composite material of the above ceramics and a metal. The metal is, for example, aluminum, aluminum alloy, copper, or copper alloy. The material of the base body 2 in this example is ceramics.

[0047] A heating element, not shown in the illustration, is placed inside the base 2. The heating element is a heat source for heating the object to be heated. The shape and arrangement of the heating element are not particularly limited. Terminals, not shown in the illustration, are connected to the heating element. Power lines, not shown in the illustration, are connected to the terminals. Power is supplied to the heating element from an AC power source, not shown, via the terminals and power lines. The material of the heating element is not particularly limited as long as it is a material that can heat the object to be heated to the desired temperature. The material of each heating element is a metal suitable for resistance heating. The metal is selected from the group consisting of, for example, stainless steel, nickel, nickel alloys, silver, silver alloys, tungsten, tungsten alloys, molybdenum, molybdenum alloys, chromium, and chromium alloys. Nickel alloy is, for example, nichrome.

[0048] [Cylinder] In this example, the cylindrical body 3 is cylindrical in shape. The cylindrical body 3 is arranged concentrically with the base body 2. In this example, the base body 2 and the cylindrical body 3 are connected such that the center of the cylindrical body 3 and the center of the disc-shaped base body 2 are coaxial. The material of the cylindrical body 3 is ceramic, the same as the material of the base body 2. The material of the cylindrical body 3 and the material of the base body 2 may be the same or different.

[0049] The upper end 31 and lower end 32 of the cylindrical body 3 are provided with outwardly bent flange portions 31a and 32a. In this example, an upper sealing member 71 is positioned between the flange portion 31a and the lower surface 2b, and a lower sealing member 72 is positioned between the flange portion 32a and the upper surface 41a of the first plate 41, which will be described later. In this example, the flange portion 32a is fixed to the upper surface 41a of the first plate 41 by a plurality of first fixing screws 57. Each first fixing screw 57 penetrates the flange portion 32a and is connected to the first plate 41. The lower sealing member 72 is positioned on the inner circumference side of the flange portion 32a relative to each first fixing screw 57. The inside of the cylindrical body 3 is sealed by the upper sealing member 71 and the lower sealing member 72. The terminals and power lines described above are arranged inside the cylindrical body 3. Typically, the chamber is filled with corrosive gas. By maintaining airtightness inside the cylindrical body 3, the aforementioned terminals and power lines housed inside the cylindrical body 3 can be isolated from corrosive gases. Unlike this example, the upper sealing member 71 is not provided, and the flange portion 31a and the lower surface 2b may be joined by sintering or screw to prevent corrosive gases from flowing into the inside of the cylindrical body 3 from between the flange portion 31a and the lower surface 2b. Similarly, the lower sealing member 72 is not provided, and the flange portion 32a and the upper surface 41a may be joined by sintering or screw to prevent corrosive gases from flowing into the inside of the cylindrical body 3 from between the flange portion 32a and the upper surface 41a.

[0050] [Plate 1, Plate 2] The lower end 32 of the cylindrical body 3 is fixed to the first plate 41. The second plate 42 is positioned below the first plate 41. The first plate 41 and the second plate 42 are connected by a second screw 52, ​​which will be described later. The second plate 42 is fixed to the annular mounting base 9 by a second fixing screw 58. There are three or more second fixing screws 58. The number of second fixing screws 58 shown in Figures 8 to 20 is six. The six second fixing screws 58 will be described later. Although not shown in the illustration, the number of second fixing screws 58 may be three, four, eight, nine, or twelve. The connection configuration between the first plate 41, the second plate 42, and the mounting base 9 will be described later. Depending on the connection configuration, the first plate 41 and the second plate 42 have screw holes, through holes, etc. Details will be described later.

[0051] In this example, the first plate 41 and the second plate 42 have an annular plate shape. In Figures 1 to 5, for the sake of explanation, the central through-holes of the first plate 41 and the second plate 42 are not shown. Power lines and the like are routed out from the central through-holes of the first plate 41 and the second plate 42 to below the lower surface 42b of the second plate 42. In this example, the cylindrical body 3 and the first plate 41 are connected, and the first plate 41 and the second plate 42 are connected, such that the centers of the cylindrical body 3, the annular plate-shaped first plate 41, and the annular plate-shaped second plate 42 are coaxial. Unlike this example, the first plate 41 and the second plate 42 may be connected such that the centers of the annular plate-shaped first plate 41 and the annular plate-shaped second plate 42 are at different positions.

[0052] The materials of the first plate 41 and the second plate 42 are, for example, aluminum, aluminum alloy, or stainless steel. The materials of the second plate 42 and the first plate 41 may be the same or different.

[0053] The first plate 41 has an upper surface 41a and a lower surface 41b. The lower end 32 of the cylindrical body 3 is fixed to the upper surface 41a. The lower surface 41b is the opposite surface of the upper surface 41a. The lower surface 41b faces the upper surface 42a of the second plate 42, which will be described later. The second plate 42 has an upper surface 42a and a lower surface 42b. The upper surface 42a faces the lower surface 41b of the first plate 41. The lower surface 42b is the opposite surface of the upper surface 42a. The lower surface 42b is placed on the upper surface 91 of the mounting base 9. A sealing member 6, which will be described later, is positioned between the lower surface 41b of the first plate 41 and the upper surface 42a of the second plate 42.

[0054] The lower surface 41b of the first plate 41 or the upper surface 42a of the second plate 42 may have one or more grooves configured in an annular shape. The number of grooves is the same as the number of sealing members 6 described later. In this example, there are two grooves. In this example, as shown in Figure 6 or Figure 7, the upper surface 42a of the second plate 42 has a first groove 42i and a second groove 42k. In this example, the first groove 42i and the second groove 42k are arranged concentrically. Unlike this example, the first groove 42i and the second groove 42k may be arranged such that the center of the first groove 42i and the center of the second groove 42k are at different positions. The centers of the first groove 42i and the second groove 42k are the centers of the envelope of the first plate 41 or the center of the envelope of the second plate 42. In this example, the centers of the first groove 42i and the second groove 42k are the centers of the envelope of the second plate 42. In other words, in this example, the center of the first groove 42i and the center of the second groove 42k are in the same position as the center of the envelope of the second plate 42. Unlike this example, the centers of the first groove 42i and the second groove 42k may be in different positions from the center of the envelope of the first plate 41 and the center of the envelope of the second plate 42.

[0055] In this example, the first groove 42i and the second groove 42k are configured in an annular shape. The diameter of the second groove 42k is larger than the diameter of the first groove 42i. A first sealing member 61, described later, is placed in the first groove 42i. A second sealing member 62, described later, is placed in the second groove 42k. The depth D1 of the first groove 42i and the depth D2 of the second groove 42k may be the same, as shown in Figure 6, or they may be different, as shown in Figure 7. When the depth D1 of the first groove 42i and the depth D2 of the second groove 42k are different, for example, the depth D2 of the second groove 42k is shallower than the depth D1 of the first groove 42i. The depth D1 of the first groove 42i is, for example, 1 to 5 times, more specifically 1 to 4 times, and more particularly 1 to 3 times, the depth D2 of the second groove 42k.

[0056] [Sealing material] The sealing member 6 seals the space between the first plate 41 and the second plate 42. The sealing member 6 is configured in an annular shape. There is one or more sealing members 6. In this example, there are two sealing members 6. The sealing member 6 has a first sealing member 61 and a second sealing member 62. The first sealing member 61 and the second sealing member 62 are arranged concentrically. The first sealing member 61 and the second sealing member 62 are configured in an annular shape. The diameter of the second sealing member 62 is larger than the diameter of the first sealing member 61. The first sealing member 61 is located in the first groove 42i. The second sealing member 62 is located in the second groove 42k. That is, the centers of the first sealing member 61 and the second sealing member 62 are the centers of the envelope of the second plate 42.

[0057] The thickness T1 of the first seal member 61 and the thickness T2 of the second seal member 62 may be different, as shown in Figure 6, or the same, as shown in Figure 7. Here, the thickness T1 of the first seal member 61 and the thickness T2 of the second seal member 62 refer to the thickness when no external force is acting. When no external force is acting, it means that no force other than gravity is acting. When the heater 1 is in use, the first seal member 61 and the second seal member 62 are compressed by the lower surface 41b of the first plate 41 and the upper surface 42a of the second plate 42. When no external force is acting, it means that the first seal member 61 and the second seal member 62 are not compressed by the lower surface 41b of the first plate 41 and the upper surface 42a of the second plate 42, but rather when the first seal member 61 and the second seal member 62 are placed on a flat surface.

[0058] As shown in Figure 6, when the depth D1 of the first groove 42i and the depth D2 of the second groove 42k are the same, the thickness T2 of the second seal member 62 is greater than the thickness T1 of the first seal member 61. The thickness T2 of the second seal member 62 is, for example, 1 to 7 times the thickness T1 of the first seal member 61, and moreover, 1 to 5 times, and especially 1 to 3 times. As shown in Figure 7, when the depth D2 of the second groove 42k is shallower than the depth D1 of the first groove 42i, the thickness T1 of the first seal member 61 and the thickness T2 of the second seal member 62 may be the same.

[0059] [First thread, second thread] As shown in Figures 1 to 5, each first screw 51 is connected to either the second plate 42 or the first plate 41 so as to press against the lower surface 41b of the first plate 41 or the upper surface 42a of the second plate 42. Each second screw 52 fastens the first plate 41 and the second plate 42 so as to pull the lower surface 41b of the first plate 41 towards the upper surface 42a of the second plate 42. The connection and arrangement configurations of each first screw 51 and each second screw 52 will be described later.

[0060] The number of first screws 51 and second screws 52 are the same. The more first screws 51 and second screws 52 there are, the easier it is to locally adjust the gap between the lower surface 41b of the first plate 41 and the upper surface 42a of the second plate 42. The fewer first screws 51 and second screws 52 there are, the easier it is to reduce the effort required to adjust the gap between the lower surface 41b of the first plate 41 and the upper surface 42a of the second plate 42. The number of first screws 51 and second screws 52 shown in Figures 8 to 20 is 3. Although not shown, the number of first screws 51 and second screws 52 may be 4, 5, 6, 8, 9, or 12.

[0061] The material of each first screw 51 and each second screw 52 is, for example, stainless steel. The material of the first screw 51 and the material of the second screw 52 may be the same or different. The thread diameter of the first screw 51 and the thread diameter of the second screw 52 may be the same or different.

[0062] [Connection type] Referring to Figures 1 to 5, the first to fifth examples of connection configurations for the first screw 51 and the second screw 52 will be described. In the following description, when "diameter" refers to the diameter of an inner circumferential surface, such as the diameter of a through hole, screw hole, counterbore hole, or communication hole, it means the diameter of the inscribed circle of the inner circumferential surface. When referring to the diameter of an outer circumferential surface, such as the diameter of the male thread portion of a screw, it means the diameter of the envelope of the outer circumferential surface.

[0063] (Example 1) The first example shown in Figure 1 satisfies the following requirements (A1) and (B1). (A1) Three or more first screws 51 are connected to the first screw holes 42c of the second plate 42 so as to press against the lower surface 41b of the first plate 41. (B1) Three or more second screws 52 are inserted from below the second plate 42 through the first through hole 42f of the second plate 42 and connected to the second screw hole 41d of the first plate 41, thereby fastening the first plate 41 and the second plate 42 together, such that the lower surface 41b of the first plate 41 is pulled towards the upper surface 42a of the second plate 42.

[0064] The first plate 41 has a plurality of first screw holes 41c and three or more second screw holes 41d. Each first screw hole 41c is provided on the upper surface 41a of the first plate 41. The number of first screw holes 41c is the same as the number of first fixing screws 57. Each first fixing screw 57 is connected to each first screw hole 41c. Each second screw hole 41d is provided on the lower surface 42b of the second plate 42. Each second screw hole 41d is provided inside the first sealing member 61 and inside the mounting base 9. The number of second screw holes 41d is the same as the number of second screws 52.

[0065] The second plate 42 has three or more first screw holes 42c, three or more first through holes 42f, and three or more second through holes 42g. Each first screw hole 42c is located inside the first sealing member 61 and inside the mounting base 9. Each first screw hole 42c extends from the upper surface 42a to the lower surface 42b of the second plate 42. The number of first screw holes 42c is the same as the number of first screws 51. Each first through hole 42f penetrates the upper surface 42a and the lower surface 42b of the second plate 42. The number of first through holes 42f is the same as the number of second screws 52. Each first through hole 42f is located such that its center is coaxial with the center of each second screw hole 41d of the first plate 41. Specifically, each first through-hole 42f is located inside the first sealing member 61 and inside the mounting base 9. The diameter of each first through-hole 42f is larger than the diameter of the male thread portion 52b of each second screw 52, ​​which will be described later. Each second through-hole 42g penetrates the upper surface 42a and the lower surface 42b of the second plate 42. Each second through-hole 42g is located outside the second sealing member 62 and in the area overlapping the mounting base 9. The number of second through-holes 42g is the same as the number of second fixing screws 58. Each second through-hole 42g consists of a counterbore hole and a communication hole, in order from the upper surface 42a to the lower surface 42b of the second plate 42. The diameter of each communication hole is smaller than the diameter of each counterbore hole. The diameter of each communication hole is larger than the diameter of the male threaded portion 58b of each second fixing screw 58 (described later) and smaller than the diameter of the head 58a of each second fixing screw 58.

[0066] The mounting base 9 has three or more screw holes 93. Each screw hole 93 is located on the upper surface 91 of the mounting base 9. The number of screw holes 93 is the same as the number of second fixing screws 58. Each screw hole 93 is located such that its center is coaxial with the center of each second through hole 42g of the second plate 42. Each screw hole 93 is located on the outside of the base seal member 75 that seals the space between the lower surface 42b of the second plate 42 and the upper surface 91 of the mounting base 9.

[0067] Each first screw 51 is longer than the thickness of the second plate 42, but shorter than the combined thickness of the first plate 41 and the second plate 42. Each first screw 51 has a head 51a, a male threaded portion 51b, and a tip 51c. The head 51a faces the lower surface 42b of the second plate 42. The male threaded portion 51b is connected to the first screw hole 42c of the second plate 42. The tip 51c is in contact with the lower surface 41b of the first plate 41.

[0068] Each second screw 52 is longer than the thickness of the second plate 42 and shorter than the combined thickness of the first plate 41 and the second plate 42. Each second screw 52 has a head 52a and a male threaded portion 52b. The head 52a is in contact with the lower surface 42b of the second plate 42. The male threaded portion 52b has a portion that is positioned inside the first through hole 42f of the second plate 42 without being coupled, and a portion that is coupled to the second threaded hole 41d of the first plate 41.

[0069] Each second fixing screw 58 is longer than the thickness of the second plate 42 and shorter than the combined thickness of the second plate 42 and the mounting base 9. Each second fixing screw 58 has a head 58a and a male threaded portion 58b. The head 58a is positioned in the counterbore of the second through hole 42g. The head 58a is in contact with the bottom surface of the counterbore. The male threaded portion 58b has a portion that is positioned inside the communication hole of the second through hole 42g without being coupled, and a portion that is coupled to the threaded hole 93 of the mounting base 9.

[0070] (Second example) The second example shown in Figure 2 is the same as the first example, except that the first screw 51 presses against the upper surface 42a of the second plate 42 and the second screw 52 is inserted from above the first plate 41. The second example satisfies the following requirements (A2) and (B2). (A2) Three or more first screws 51 are connected to the third screw holes 41e of the first plate 41 so as to press against the upper surface 42a of the second plate 42. (B2) Three or more second screws 52 are inserted into the first through-hole 41f of the first plate 41 from above the first plate 41 and coupled to the second screw hole 42d of the second plate 42, thereby fastening the first plate 41 and the second plate 42 together, such that the lower surface 41b of the first plate 41 is pulled towards the upper surface 42a of the second plate 42.

[0071] The first plate 41 has the same number of first screw holes 41c as in the first example, three or more third screw holes 41e not present in the first example, and three or more first through holes 41f not present in the first example. The first plate 41 does not have the second screw holes 41d of the first example. Each third screw hole 41e is located outside the second sealing member 62. Each third screw hole 41e extends from the upper surface 41a to the lower surface 41b of the first plate 41. The number of third screw holes 41e is the same as the number of first screws 51. Each first through hole 41f penetrates the upper surface 41a and the lower surface 41b of the first plate 41. Each first through hole 41f is located outside the second sealing member 62. The number of first through holes 41f is the same as the number of second screws 52. The diameter of each first through hole 41f is greater than the diameter of the male threaded portion 52b of each second screw 52.

[0072] The second plate 42 has three or more second screw holes 42d, which are not present in the first example, and three or more second through holes 42g, which are the same as those in the first example. The second plate 42 does not have the first screw holes 42c and the first through holes 42f of the first example. Each second screw hole 42d is provided on the upper surface 42a of the second plate 42. The number of second screw holes 42d is the same as the number of second screws 52. Each second screw hole 42d is provided such that the center of each second screw hole 42d is coaxial with the center of each first through hole 41f of the first plate 41. That is, each second screw hole 42d is provided outside the second sealing member 62.

[0073] Each first screw 51 is longer than the thickness of the first plate 41 and shorter than the combined thickness of the first plate 41 and the second plate 42. Each first screw 51 has a head 51a, a male threaded portion 51b, and a tip 51c. The head 51a faces the upper surface 41a of the first plate 41. The male threaded portion 51b is connected to the third screw hole 41e of the first plate 41. The tip 51c is in contact with the upper surface 42a of the second plate 42.

[0074] Each second screw 52 is longer than the thickness of the first plate 41 and shorter than the combined thickness of the first plate 41 and the second plate 42. Each second screw 52 has a head 52a and a male threaded portion 52b. The head 52a is in contact with the upper surface 41a of the first plate 41. The male threaded portion 52b has a portion that is positioned inside the first through hole 41f of the first plate 41 without being coupled, and a portion that is coupled to the second threaded hole 42d of the second plate 42.

[0075] (Third example) The third example shown in Figure 3 is the same as the first example, except that the second screw 52 is inserted from above the first plate 41. The third example is also the same as the second example, except that the first screw 51 is pressing against the lower surface 41b of the first plate 41. The third example satisfies the following requirements (A3) and (B3). (A3) Three or more first screws 51 are connected to the first screw holes 42c of the second plate 42 so as to press against the lower surface 41b of the first plate 41. (B3) Three or more second screws 52 are inserted into the first through holes 41f of the first plate 41 from above the first plate 41 and coupled to the second screw holes 42d of the second plate 42, thereby fastening the first plate 41 and the second plate 42 together, such that the lower surface 41b of the first plate 41 is pulled towards the upper surface 42a of the second plate 42.

[0076] The first plate 41 has the same number of first screw holes 41c as in the first example, and three or more first through holes 41f as in the second example. The first plate 41 does not have the second screw hole 41d in the first example or the third screw hole 41e in the second example.

[0077] The second plate 42 has three or more first screw holes 42c, the same as the first screw holes 42c of the first example, three or more second screw holes 42d, the same as the second screw holes 42d of the second example, and three or more second through holes 42g, the same as the second through hole 42g of the first example. The second plate 42 does not have the first through hole 42f of the first example.

[0078] (Fourth example) The fourth example shown in Figure 4 is the same as the first example, except that the second fixing screw 58 is inserted from below the mounting base 9. The fourth example satisfies the following requirements (A4) and (B4). (A4) Three or more first screws 51 are connected to the first screw holes 42c of the second plate 42 so as to press against the lower surface 41b of the first plate 41. (B4) Three or more second screws 52 are inserted into the first through holes 42f of the second plate 42 from below the second plate 42 and connected to the second screw holes 41d of the first plate 41, thereby fastening the first plate 41 and the second plate 42 in such a way that the lower surface 41b of the first plate 41 is pulled towards the upper surface 42a of the second plate 42.

[0079] The second plate 42 has three or more first screw holes 42c, the same as the first screw holes 42c of the first example, three or more first through holes 42f, the same as the first through holes 42f of the first example, and three or more third screw holes 42e, which are not present in the first example. The second plate 42 does not have the second through hole 42g of the first example. Each third screw hole 42e is provided on the lower surface 42b of the second plate 42. Each third screw hole 42e is provided in the area inside the base seal member 75 and overlapping the mounting base 9. The number of third screw holes 42e is the same as the number of second fixing screws 58.

[0080] The mounting base 9 has three or more first through holes 94, which are not present in the first example. The mounting base 9 does not have the screw holes 93 of the first example. Each first through hole 94 penetrates the upper surface 91 and the lower surface 92 of the mounting base 9. The number of first through holes 94 is the same as the number of second fixing screws 58. Each first through hole 94 is positioned such that its center is coaxial with the center of each third screw hole 42e of the second plate 42. Each first through hole 94 is positioned inside the base seal member 75. The diameter of each first through hole 94 is greater than the diameter of the male threaded portion 58b of each second fixing screw 58.

[0081] The length of each second fixing screw 58 is longer than the thickness of the mounting base 9, and shorter than the combined thickness of the second plate 42 and the mounting base 9. Each second fixing screw 58 has a head 58a and a male threaded portion 58b. The head 58a is in contact with the lower surface 92 of the mounting base 9. The male threaded portion 58b has a portion that is positioned inside the first through hole 94 of the mounting base 9 without being coupled, and a portion that is coupled to the third threaded hole 42e of the second plate 42.

[0082] (Example 5) The fifth example shown in Figure 5 is the same as the fourth example, except that three or more first screw holes 42c of the second plate 42 are provided in the region overlapping the mounting base 9, three or more first through holes 42f of the second plate 42 are provided in the region overlapping the mounting base 9, and the mounting base 9 further has second through holes 95 and third through holes 96. The fifth example satisfies the following requirements (A5) and (B5). (A5) Three or more first screws 51 are connected to the first screw holes 42c of the second plate 42 so as to press against the lower surface 41b of the first plate 41. (B5) Three or more second screws 52 are inserted into the first through holes 42f of the second plate 42 from below the second plate 42 and connected to the second screw holes 41d of the first plate 41, thereby fastening the first plate 41 and the second plate 42 in such a way that the lower surface 41b of the first plate 41 is pulled towards the upper surface 42a of the second plate 42.

[0083] The second plate 42 has three or more first screw holes 42c similar to the first screw holes 42c of the fourth example, three or more first through holes 42f similar to the first through holes 42f of the fourth example, and three or more third screw holes 42e similar to the third screw holes 42e of the fourth example. The second plate 42 does not have the second through hole 42g of the first example. The three or more first screw holes 42c include first screw holes 42c located inside the first sealing member 61 and inside the mounting base 9, and first screw holes 42c located inside the first sealing member 61 and in a region overlapping the mounting base 9. The three or more first through holes 42f include first through holes 42f located inside the first sealing member 61 and inside the mounting base 9, and first through holes 42f located inside the first sealing member 61 and in a region overlapping the mounting base 9.

[0084] The mounting base 9 has three or more first through holes 94, the same as in the fourth example, a second through hole 95, which is not present in the fourth example, and a third through hole 96, which is also not present in the fourth example. The second through holes 95 and the third through holes 96 penetrate the upper surface 91 and the lower surface 92 of the mounting base 9. The second through holes 95 and the third through holes 96 are located inside the base seal member 75. The second through hole 95 is positioned such that its center is coaxial with the center of the first screw hole 42c, which is located inside the first seal member 61 of the second plate 42 and overlaps with the mounting base 9. The diameter of the second through hole 95 is larger than the diameter of the male screw portion 51b of the first screw 51. The third through-hole 96 is provided such that its center is coaxial with the center of the first through-hole 42f, which is located inside the first sealing member 61 of the second plate 42 and overlaps with the mounting base 9. The diameter of the third through-hole 96 is larger than the diameter of the male threaded portion 52b of the second screw 52.

[0085] Three or more first screws 51 include one or more first screws 51 that are the same as the first screws 51 of the first example and one or more first screws 51 that are different from the first screws 51 of the first example. The length of the first screws 51 that are different from the first example is longer than the combined thickness of the second plate 42 and the mounting base 9, and shorter than the combined thickness of the first plate 41, the second plate 42 and the mounting base 9. The first screws 51 that are different from the first example have a head 51a, a male threaded portion 51b and a tip portion 51c. The head 51a of the first screws 51 that are different from the first example faces the lower surface 92 of the mounting base 9. The male threaded portion 51b of the first screws 51 that are different from the first example has a portion that is not coupled to the inside of the second through hole 95 of the mounting base 9 and a portion that is coupled to the first screw hole 42c of the second plate 42. Unlike the first example, the tip 51c of the first screw 51 is in contact with the lower surface 41b of the first plate 41.

[0086] Three or more second screws 52 include one or more second screws 52 that are the same as the second screws 52 of the first example and one or more second screws 52 that are different from the second screws 52 of the first example. The length of the second screws 52 that are different from the first example is longer than the combined thickness of the second plate 42 and the mounting base 9, and shorter than the combined thickness of the first plate 41, the second plate 42 and the mounting base 9. The second screws 52 that are different from the first example have a head 52a and a male threaded portion 52b. The head 52a of the second screws 52 that are different from the first example is in contact with the lower surface 92 of the mounting base 9. The male threaded portion 52b of the second screws 52 that are different from the first example has a portion that is located inside the third through hole 96 of the mounting base 9 without being coupled, a portion that is located inside the first through hole 42f of the second plate 42 without being coupled, and a portion that is coupled to the second screw hole 41d of the first plate 41.

[0087] [Arrangement form] Referring to Figures 8 to 20, the first to thirteenth examples of the arrangement configurations of the first screw 51 and the second screw 52 will be described. Figures 8 to 20 are perspective views of the first plate 41 from above. In Figures 8 to 20, for the sake of explanation, the first fixing screw 57, the first sealing member 61, the second sealing member 62, the first groove 42i, the second groove 42k, and the mounting base 9 are omitted from the illustration. In Figures 8 to 20, for the sake of explanation, the first screw 51, the second screw 52, ​​and the second fixing screw 58 are shown as hatched circles. In Figures 8 to 20, the six second fixing screws 58 are arranged at equal intervals on the circumference of a reference circle Cr centered at the center a of the envelope circle of the first plate 41. Equal intervals do not mean strictly equal intervals, but rather substantially equal intervals. Substantially equal intervals also include all of the above spacing distances being the same. The following equal intervals have the same significance as described above. The six second fixing screws 58 are positioned at the 1 o'clock, 3 o'clock, 5 o'clock, 7 o'clock, 9 o'clock, and 11 o'clock positions in a clock position where the upward direction in the figure is 12 o'clock from the center a. In Figures 8 to 20, the circles passing through the center of the envelope of the male thread portion 51b of each first screw 51, the circles passing through the center of the envelope of the male thread portion 52b of each second screw 52, ​​and the circles passing through the center of the envelope of the male thread portion 58b of each second fixing screw 58 are shown as dashed lines with center a as the center.

[0088] (Example 1) In the first example shown in Figure 8, three first screws 51 are arranged on the circumference of the first circle C1, and three second screws 52 are arranged on the circumference of the second circle C2. The first circle C1 is a circle centered at center a, and the second circle C2 is a circle centered at center a. "Arranged on the circumference of a circle" does not mean strictly so, but rather that they are substantially arranged on the circumference of a circle. Substantially arranged on the circumference of a circle includes, for example, cases where the male threaded portion 51b of each first screw 51 is inscribed in, overlapping with, or circumscribed on the first circle C1. Of course, substantially arranged on the circumference of a circle also includes cases where the center of each first screw 51 is located on the circumference of the first circle C1.

[0089] The first circle C1, the second circle C2, and the reference circle Cr are the same circle. That is, the three first screws 51, the three second screws 52, and the six second fixing screws 58 are arranged on the circumference of the same circle. The three first screws 51 are arranged at equal intervals on the circumference of the first circle C1. The three second screws 52 are arranged at equal intervals on the circumference of the second circle C2.

[0090] The three first screws 51 are positioned substantially at the 12 o'clock, 4 o'clock, and 8 o'clock positions. The three second screws 52 are positioned substantially at the 12 o'clock, 4 o'clock, and 8 o'clock positions. The first screws 51 and second screws 52 at each position are adjacent to each other in the direction along the axis of center a.

[0091] (Second example) The second example shown in Figure 9 is the same as the first example, except that the positions of the three first screws 51 are closer to the center a than the positions of the three second screws 52. The first circle C1 and the second circle C2 are concentric circles with different radii. The radius of the first circle C1 is smaller than the radius of the second circle C2. The three first screws 51 and the six second fixing screws 58 are arranged on the circumferences of different circles.

[0092] (Third example) The third example shown in Figure 10 is the same as the first example, except that the positions of the three second screws 52 are closer to the center a than the positions of the three first screws 51. The first circle C1 and the second circle C2 are concentric circles with different radii. The radius of the second circle C2 is smaller than the radius of the first circle C1. The three second screws 52 and the six second fixing screws 58 are arranged on the circumferences of different circles.

[0093] (Fourth example) The fourth example shown in Figure 11 is the same as the first example, except that the positions of the three second screws 52 are in the direction along the axis a of the center a. The three second screws 52 are positioned at the 2 o'clock, 6 o'clock, and 10 o'clock positions. Each first screw 51 and each second screw 52 are positioned such that each second fixing screw 58 is sandwiched between them.

[0094] (Example 5) The fifth example shown in Figure 12 is the same as the fourth example, except that the positions of the three first screws 51 are closer to the center a than the positions of the three second screws 52. The first circle C1 and the second circle C2 are concentric circles with different radii. The radius of the first circle C1 is smaller than the radius of the second circle C2. The three first screws 51 and the six second fixing screws 58 are arranged on the circumferences of different circles.

[0095] (Example 6) The sixth example shown in Figure 13 is the same as the fourth example, except that the positions of the three second screws 52 are closer to the center a than the positions of the three first screws 51. The first circle C1 and the second circle C2 are concentric circles with different radii. The radius of the second circle C2 is smaller than the radius of the first circle C1. The three second screws 52 and the six second fixing screws 58 are arranged on the circumferences of different circles.

[0096] (Example 7) The seventh example shown in Figure 14 is the same as the first example, except that the positions of the three first screws 51 and the three second screws 52 are closer to the center a than the positions of the six second fixing screws 58. The radii of the first circle C1 and the second circle C2 in this example are smaller than the radii of the first circle C1 and the second circle C2 in the first example.

[0097] (Example 8) In the eighth example shown in Figure 15, the positions of the three second screws 52 are closer to center a than the positions of the six second fixing screws 58, and the positions of the three first screws 51 are closer to center a than the positions of the three second screws 52. The first circle C1 and the second circle C2 are concentric circles with different radii. In this example, the radius of the first circle C1 is smaller than the radius of the second circle C2. The three first screws 51 are located at the 1 o'clock, 5 o'clock, and 9 o'clock positions. The three second screws 52 are located at the 1 o'clock, 5 o'clock, and 9 o'clock positions.

[0098] Unlike this example, although not shown in the illustration, the positions of the three first screws 51 may be closer to center a than the positions of the six second fixing screws 58, and the positions of the three second screws 52 may be closer to center a than the positions of the three first screws 51. In other words, the radius of the second circle C2 may be smaller than the radius of the first circle C1.

[0099] (Example 9) The ninth example shown in Figure 16 is the same as the seventh example, except for the position of the three first screws 51 along the axis a of the center a. The three first screws 51 are positioned at the 2 o'clock, 6 o'clock, and 10 o'clock positions.

[0100] (Example 10) The tenth example shown in Figure 17 is the same as the first example, except that one of the three first screws 51 is located closer to center a than the other two first screws 51, and one of the three second screws 52 is located closer to center a than the other two second screws 52. One first screw 51 and one second screw 52 are arranged on the circumference of the fourth circle C4. The remaining two first screws 51 and the remaining two second screws 52 are arranged on the circumference of the fifth circle C5. The fourth circle C4 and the fifth circle C5 are circles centered at center a. The fourth circle C4 and the fifth circle C5 are concentric circles with different radii. The radius of the fourth circle C4 is smaller than the radius of the fifth circle C5. The fifth circle C5 and the reference circle Cr are the same circle. The first screw 51 and the second screw 52 on the circumference of the fourth circle C4 are positioned at the 12 o'clock position. The two first screws 51 on the circumference of the fifth circle C5 are positioned at the 4 o'clock position and the 8 o'clock position. In other words, the first screw 51 and the second screw 52 positioned at the 12 o'clock position are closer to the center a than the first screw 51 and the second screw 52 positioned at the 4 o'clock position and the first screw 51 and the second screw 52 positioned at the 8 o'clock position.

[0101] Unlike this example, although not shown in the illustration, the first screw 51 and second screw 52 located at the 12 o'clock position are arranged on the same circumference as the six second fixing screws 58, and the first screw 51 and second screw 52 located at the 4 o'clock position and the first screw 51 and second screw 52 located at the 8 o'clock position may be located closer to the center a than the first screw 51 and second screw 52 located at the 12 o'clock position.

[0102] (Example 11) The eleventh example shown in Figure 18 is the same as the first example, except that the three first screws 51 are not evenly spaced on the circumference of the first circle C1, and the three second screws 52 are not evenly spaced on the circumference of the second circle C2. The three first screws 51 are arranged such that when the centers of adjacent first screws 51 are connected by straight lines along the axis of center a, center a is located in the region enclosed by the three straight lines. The three first screws 51 are located between 4 o'clock and 5 o'clock, between 8 o'clock and 9 o'clock, and at the 12 o'clock position. The three second screws 52 are arranged such that when the centers of adjacent second screws 52 are connected by straight lines along the axis of center a, center a is located in the region enclosed by the three straight lines. The three second screws 52 are located between 4 o'clock and 5 o'clock, between 9 o'clock and 10 o'clock, and at the 12 o'clock position.

[0103] (Example 12) The twelfth example shown in Figure 19 is the same as the first example, except that the three first screws 51 are not equally spaced on the circumference of the first circle C1, the positions of the three second screws 52 are closer to center a than the positions of the three first screws 51, and the three second screws 52 are not equally spaced on the circumference of the second circle C2. The first circle C1 and the second circle C2 are concentric circles with different radii. The radius of the second circle C2 is smaller than the radius of the first circle C1. The three first screws 51 are arranged such that when the centers of adjacent first screws 51 are connected by straight lines along the axis of center a, center a is located in the region enclosed by the three straight lines. The first screws 51 are located between 4 o'clock and 5 o'clock, between 6 o'clock and 7 o'clock, and between 11 o'clock and 12 o'clock. Three second screws 52 are arranged such that when the centers of adjacent second screws 52 are connected by straight lines along the axis of center a, center a is located in the region enclosed by the three straight lines. The second screws 52 are positioned between 4 o'clock and 5 o'clock, between 6 o'clock and 7 o'clock, and between 11 o'clock and 12 o'clock.

[0104] (Example 13) The 13th example shown in Figure 20 is the same as the first example, except that one of the three first screws 51 is located closer to center a than the other two first screws 51, and two of the three second screws 52 are located closer to center a than the remaining second screw 52. One first screw 51 is located on the circumference of the sixth circle C6. The remaining two first screws 51 are located on the circumference of the seventh circle C7. The two second screws 52 are located on the circumference of the eighth circle C8. The remaining second screw 52 is located on the circumference of the seventh circle C7. The sixth circle C6, the seventh circle C7, and the eighth circle C8 are circles centered at center a. The sixth circle C6, the seventh circle C7, and the eighth circle C8 are concentric circles with different radii. The radius of circle 8 C8 is smaller than the radius of circle 6 C6, and the radius of circle 6 C6 is smaller than the radius of circle 7 C7. Circle 7 C7 and reference circle Cr are the same circle.

[0105] In the case of one first screw 51 on the circumference of the sixth circle C6 and two first screws 51 on the circumference of the seventh circle C7, the three first screws 51 are arranged such that when the centers of adjacent first screws 51 are connected by straight lines in the direction along the axis of center a, center a is located in the region enclosed by the three straight lines. The one first screw 51 on the circumference of the sixth circle C6, which is close to center a, is located between 10 o'clock and 11 o'clock. The two first screws 51 on the circumference of the seventh circle C7, which are farther from center a, are located between 3 o'clock and 4 o'clock and between 6 o'clock and 7 o'clock. In the case of one second screw 52 on the circumference of the seventh circle C7 and two second screws 52 on the circumference of the eighth circle C8, the three second screws 52 are arranged such that when the centers of adjacent second screws 52 are connected by straight lines in the direction along the axis of center a, center a is located in the region enclosed by the three straight lines. The two second screws 52 on the circumference of the eighth circle C8, which is located near the center a, are positioned between 2 o'clock and 3 o'clock and between 7 o'clock and 8 o'clock. The one second screw 52 on the circumference of the seventh circle C7, which is located farther from the center a, is positioned between 11 o'clock and 12 o'clock.

[0106] Depending on the thickness of the sealing member 6, the distance between the periphery of the lower surface 41b of the first plate 41 and the upper surface 42a of the second plate 42 can be adjusted within a range of 0 mm to 1 mm using the first screws 51 and the second screws 52. Depending on the length of the cylindrical body 3 and the diameter of the base body 2, by adjusting the above distance within the above range, the movable range of the periphery of the upper surface 2a of the base body 2 can be set to, for example, 0 mm to 2 mm.

[0107] [Example of adjusting the interval] An example of adjusting the gap between the lower surface 41b of the first plate 41 and the upper surface 42a of the second plate 42 will be described. This explanation assumes that the arrangement is the first example shown in Figure 8. For example, to widen the gap between the lower surface 41b of the first plate 41 and the upper surface 42a of the second plate 42, which corresponds to the 12 o'clock position, by 0.5 mm, do the following: Rotate the first screw 51 and the second screw 52 located at the 12 o'clock position, the first screw 51 and the second screw 52 located at the 4 o'clock position, and the first screw 51 and the second screw 52 located at the 8 o'clock position. By rotating the first screw 51 and the second screw 52 located at the 4 o'clock position, the gap between the lower surface 41b of the first plate 41 and the upper surface 42a of the second plate 42, which corresponds to the 4 o'clock position, will be widened by 0.3 mm. By rotating the first screw 51 and the second screw 52 located at the 8 o'clock position, the gap between the lower surface 41b of the first plate 41 and the upper surface 42a of the second plate 42 corresponding to the 8 o'clock position is widened by 0.3 mm. The above gap corresponding to the 4 o'clock position is widened by 0.3 mm, and the above gap corresponding to the 8 o'clock position is widened by 0.3 mm. In addition, by rotating the first screw 51 and the second screw 52 located at the 12 o'clock position, the above gap corresponding to the 12 o'clock position can be widened by 0.5 mm.

[0108] Embodiment 2 〔heater〕 The heater 1 of Embodiment 2 will be described with reference to Figures 21 and 22. The heater 1 of Embodiment 2 is the same as the heater 1 of Embodiment 1, except that it further comprises three or more third screws 53 that restrict the distance between the lower surface 41b of the first plate 41 and the upper surface 42a of the second plate 42 to a predetermined value or less. The following description will focus on the differences from Embodiment 1. Descriptions of configurations and effects similar to those of Embodiment 1 will be omitted. Figure 21 is based on a second example of the connection configuration in the heater 1 of Embodiment 1.

[0109] [Plate 1, Plate 2] The first plate 41 has the same number of first screw holes 41c as in the second example, three or more third screw holes 41e as in the second example, three or more first through holes 41f as in the second example, and three or more second through holes 41g which are not present in the second example. Each second through hole 41g penetrates the upper surface 41a and the lower surface 41b of the first plate 41. Each second through hole 41g is located outside the second sealing member 62. The number of second through holes 41g is the same as the number of third screws 53. The diameter of the second through holes 41g is greater than the diameter of the shaft portion 53b of the third screw 53.

[0110] The second plate 42 has three or more second screw holes 42d, the same as the second screw holes 42d in the second example, three or more second through holes 42g, the same as the second through holes 42g in the second example, and three or more third screw holes 42e, which are not present in the second example. Each third screw hole 42e is provided on the upper surface 42a of the second plate 42. Each third screw hole 42e is provided such that its center is coaxial with the center of the second through hole 41g of the first plate 41. That is, each third screw hole 42e is provided outside the second sealing member 62. The number of second screw holes 42d is the same as the number of third screws 53.

[0111] [Third screw] The number of third screws 53 is the same as the number of screws in either the first screws 51 or the second screws 52. In this example, the number of third screws 53 is the same as the number of first screws 51 and second screws 52. As shown in Figure 22, there are three third screws 53. Each third screw 53 has a head 53a facing the upper surface 41a of the first plate 41, a shaft portion 53b that is positioned inside the second through hole 41g of the first plate 41 without being coupled, and a male threaded portion 53c that is coupled to the second plate 42. By adjusting the distance between the head 53a and the upper surface 41a of the first plate 41, the maximum distance between the lower surface 41b of the first plate 41 and the upper surface 42a of the second plate 42 can be adjusted. When the first plate 41 is moved within a predetermined range in the direction away from the second plate 42, the upper surface 41a of the first plate 41 comes into contact with the head 53a of the third screw 53, so the first plate 41 cannot be moved above the head 53a. Therefore, the lower surface 41b of the first plate 41 is prevented from moving too far away from the upper surface 42a of the second plate 42. The diameter of the male thread portion 53c is smaller than the diameter of the shaft portion 53b. The end face of the shaft portion 53b is in contact with the upper surface 42a of the second plate 42.

[0112] The example shown in Figure 22 is the same as the first example of the arrangement configuration in the heater 1 of Embodiment 1, except that a third screw 53 is further arranged. The three third screws 53 are arranged on the circumference of the third circle C3. The third circle C3 is a circle centered at center a. The third circle C3 is the same circle as at least one of the first circle C1 and the second circle C2. For example, if the first circle C1 and the second circle C2 are concentric circles with different radii, then the third circle C3 is the same circle as either the first circle C1 or the second circle C2. If the first circle C1 and the second circle C2 are the same circle, as in this example, then the third circle C3 is the same circle as both the first circle C1 and the second circle C2. The three third screws 53 are arranged on the circumference of the same circle as the three first screws 51, the three second screws 52, and the six second fixing screws 58. The three third screws 53 are arranged at equal intervals on the circumference of the third circle C3. The third screws 53 are positioned at the 2 o'clock, 6 o'clock, and 10 o'clock positions.

[0113] Unlike this example, although not shown in the illustration, the three third screws 53 may be substantially positioned at the 12 o'clock, 4 o'clock, and 8 o'clock positions. The three third screws 53 do not have to be equally spaced on the circumference of the third circle C3. One or two of the three third screws 53 may be positioned closer to the center a than the remaining two or one third screw 53.

[0114] In this example, the third screw 53 is inserted from above the first plate 41, but it may also be inserted from below the second plate 42, as in this example. In that case, a through hole corresponding to the second through hole 41g is provided in the second plate 42, and a screw hole corresponding to the third screw hole 42e is provided in the first plate 41. The head 53a faces the lower surface 42b of the second plate 42. By adjusting the distance between the head 53a and the lower surface 42b of the second plate 42, the maximum distance between the lower surface 41b of the first plate 41 and the upper surface 42a of the second plate 42 can be adjusted. When the first plate 41 is moved by a predetermined range in the direction away from the second plate 42, the head 53a of the third screw 53 comes into contact with the lower surface 42b of the second plate 42. Therefore, the lower surface 41b of the first plate 41 is prevented from moving too far away from the upper surface 42a of the second plate 42.

[0115] The material of the third screw 53 may be the same as or different from the material of the first screw 51 or the second screw 52. For example, the material of the third screw 53 may be stainless steel.

[0116] Embodiment 3 〔heater〕 The heater 1 of Embodiment 3 will be described with reference to Figures 23 and 24. The heater 1 of Embodiment 3 is the same as the heater 1 of Embodiment 1, except that it mainly further comprises pin 55. The following description will focus on the differences from Embodiment 1. Descriptions of configurations and effects similar to those of Embodiment 1 will be omitted. Figures 23 and 24 are based on a second example of the connection configuration in the heater 1 of Embodiment 1.

[0117] [pin] The pin 55 is sandwiched between the lower surface 41b of the first plate 41 or the upper surface 42a of the second plate 42 and each of the three or more first screws 51. The first screws 51 press against the pin 55, and the pressed pin 55 presses against the lower surface 41b of the first plate 41 or the upper surface 42a of the second plate 42. By the pin 55 directly pressing against the lower surface 41b of the first plate 41 or the upper surface 42a of the second plate 42, the lower surface 41b of the first plate 41 or the upper surface 42a of the second plate 42 is less likely to be worn down compared to when the first screws 51 directly press against the lower surface 41b of the first plate 41 or the upper surface 42a of the second plate 42. In this example, the pin 55 is sandwiched between the upper surface 42a of the second plate 42 and each of the three or more first screws 51. The diameter of the pin 55 may be the same as the diameter of the male thread portion 51b of the first screw 51, or it may be larger or smaller than the diameter of the male thread portion 51b. If the force acting on the pin 55 by the first screw 51 is constant, then if the diameter of the pin 55 is greater than or equal to the diameter of the male thread portion 51b, the pressure acting on the upper surface 42a of the second plate 42 can be reduced compared to the case where the diameter of the pin 55 is smaller than the diameter of the male thread portion 51b. In this example, the diameter of the pin 55 is larger than the diameter of the male thread portion 51b. The material of the pin 55 is the same as that of the first screw 51.

[0118] [Plate 1, Plate 2] The first plate 41 shown in Figure 23 differs from the first plate 41 of the second example in that it further has a hole 41h. The diameter of the hole 41h is larger than the diameter of the third screw hole 41e of the first plate 41. The hole 41h communicates with the third screw hole 41e of the first plate 41. The hole 41h is positioned so that its center and the center of the third screw hole 41e are coaxial. If the diameter of the pin 55 is smaller than the diameter of the male screw portion 51b of the first screw 51, the first plate 41 does not need to have the hole 41h.

[0119] The second plate 42 shown in Figure 23 differs from the second plate 42 of the second example in that it has a recess 42h on its upper surface 42a where the pin 55 is positioned. The bottom surface of the recess 42h is aligned with the tip surface of the pin 55. If the tip surface of the pin 55 is a convex curved surface, the bottom surface of the recess 42h is a curved surface. The second plate 42 shown in Figure 24 does not have the above-mentioned recess 42h on its upper surface 42a. On the upper surface 42a of the second plate 42, the portion facing the pin 55 may be a flat surface.

[0120] The present invention is not limited to these examples, but is intended to include all modifications within the meaning and scope of the claims as shown, and equivalents thereof. [Explanation of Symbols]

[0121] 1 Heater 2 Base, 2a top surface, 2b bottom surface 3 cylinder 31 Upper end portion, 31a Flange portion 32 Lower end portion, 32a Flange portion 4 plates 41 1st plate, 41a top, 41b bottom 41c First screw hole, 41d Second screw hole, 41e Third screw hole 41f 1st through hole, 41g 2nd through hole, 41h hole 42 Second plate, 42a Top surface, 42b Bottom surface 42c First screw hole, 42d Second screw hole, 42e Third screw hole 42f First through hole, 42g Second through hole, 42h Recess 42i First groove, 42k Second groove 51 First thread, 51a Head, 51b Male thread portion, 51c Tip portion 52 Second thread, 52a Head, 52b Male thread portion 53 Third thread, 53a Head, 53b Shaft, 53c Male thread 55 Pin, 57 First fixing screw 58 Second fixing screw, 58a Head, 58b Male threaded portion 6 sealing member, 61 first sealing member, 62 second sealing member 71 Upper sealing member, 72 Lower sealing member 75 Base seal member 9 Mounting base, 91 Top surface, 92 Bottom surface 93 screw holes 94 First through hole, 95 Second through hole, 96 Third through hole Area A D1, D2: Depth, T1, T2: Thickness a center C1: 1st yen, C2: 2nd yen, C3: 3rd yen C4 4th yen, C5 5th yen, C6 6th yen C7: 7th yen, C8: 8th yen, Cr: Reference yen

Claims

1. A substrate on which the object to be heated is placed, A cylindrical body fixed to the lower surface of the base, The lower end of the cylindrical body is fixed to a first plate, A second plate is positioned below the first plate and fixed to the mounting base, One or more sealing members configured in an annular shape to seal the space between the lower surface of the first plate and the upper surface of the second plate, Three or more first screws are connected to the screw holes of the second plate or the screw holes of the first plate so as to press against the lower surface of the first plate or the upper surface of the second plate, The device comprises three or more second screws fastening the first plate and the second plate together such that the lower surface of the first plate is pulled towards the upper surface of the second plate. heater.

2. The lower surface of the first plate or the upper surface of the second plate has annularly arranged first grooves and second grooves, The diameter of the second groove is larger than the diameter of the first groove. The depth of the first groove and the depth of the second groove are the same. The number of the one or more sealing members is two, consisting of a first sealing member and a second sealing member. The thickness of the second sealing member under no load is greater than the thickness of the first sealing member under no load. The first sealing member is positioned in the first groove, The heater according to claim 1, wherein the second sealing member is arranged in the second groove.

3. The lower surface of the first plate or the upper surface of the second plate has annularly arranged first grooves and second grooves, The diameter of the second groove is larger than the diameter of the first groove. The depth of the second groove is shallower than the depth of the first groove. The number of the one or more sealing members is two, consisting of a first sealing member and a second sealing member. The thickness of the first sealing member under no load and the thickness of the second sealing member under no load are the same. The first sealing member is positioned in the first groove, The heater according to claim 1, wherein the second sealing member is arranged in the second groove.

4. The heater according to claim 2 or claim 3, wherein the first groove and the second groove are arranged concentrically.

5. The heater according to claim 4, wherein the center of the first groove and the center of the second groove are the center of the envelope of the first plate or the center of the envelope of the second plate.

6. The heater according to any one of claims 1 to 3, wherein the number of three or more first screws and the number of three or more second screws are the same.

7. The three or more first screws are arranged on the circumference of a first circle centered on the center of the envelope of the first plate. The heater according to any one of claims 1 to 3, wherein the three or more second screws are arranged on the circumference of a second circle centered on the center of the envelope of the first plate.

8. The heater according to claim 7, wherein the first circle and the second circle are the same circle.

9. The heater according to claim 7, wherein the first circle and the second circle are concentric circles with different radii.

10. The three or more first screws are arranged at equal intervals on the circumference of the first circle. The heater according to claim 7, wherein the three or more second screws are arranged at equal intervals on the circumference of the second circle.

11. The heater according to any one of claims 1 to 3, further comprising three or more third screws that restrict the distance between the lower surface of the first plate and the upper surface of the second plate to a predetermined value or less.

12. The heater according to claim 11, wherein the number of three or more third screws is the same as the number of three or more first screws and the number of three or more second screws.

13. Each of the three or more third screws is The head facing the upper surface of the first plate, The shaft portion that penetrates the first plate, The heater according to claim 11, further comprising a male screw portion coupled to the second plate.

14. The heater according to claim 11, wherein the three or more third screws are arranged on the circumference of a third circle centered on the center of the envelope of the first plate.

15. The three or more first screws are arranged on the circumference of a first circle centered on the center of the envelope of the first plate, The three or more second screws are arranged on the circumference of a second circle centered on the center of the envelope of the first plate. The heater according to claim 14, wherein the third circle is the same circle as at least one of the first circle and the second circle.

16. The heater according to claim 14, wherein the three or more third screws are arranged at equal intervals on the circumference of the third circle.

17. The heater according to any one of claims 1 to 3, further comprising a pin sandwiched between the lower surface of the first plate or the upper surface of the second plate and each of the three or more first screws.

18. The heater according to claim 17, wherein the lower surface of the first plate or the upper surface of the second plate has a recess in which the pin is arranged.

Images