Substrate heating device

Abstract

This invention provides a technique for reducing thermal warping of a cover portion while maintaining high thermal insulation in a substrate heating apparatus. The substrate heating apparatus includes a heating plate, a frame portion, and a cover portion. The heating plate heats the substrate. The frame portion has an opening at its upper part. The frame portion can accommodate the heating plate on its inner side. The cover portion closes the opening at the upper part of the frame portion. The cover portion has a top panel and a reinforcing panel. The top panel includes a thermal insulation material. The reinforcing panel has a first rib and a second rib connected to the lower surface of the top panel. The first rib and the second rib protrude downward from the lower surface of the top panel. The first rib and the second rib extend parallel to the lower surface of the top panel.

Description

Technical Field

[0001] The subject matter disclosed in this specification relates to a substrate heating device. Background Technology

[0002] For example, in the processing of various substrates such as glass substrates for display devices, the following process is widely performed: a coating liquid is applied to the substrate, and then the substrate is heated, thereby causing the components contained in the coating liquid to evaporate. The substrate heating device for performing this heat treatment is usually configured to perform the following process: the substrate is housed in a processing chamber and heated in the processing chamber.

[0003] Patent Document 1 describes a structure in which a heat-insulating material is molded from fiber-reinforced resin onto the wall of a processing chamber containing a heat-absorbing plate. This structure allows for high-temperature insulation of the processing chamber interior and maintains a high temperature on the inner wall surface, thus suppressing the adhesion and solidification of sublimations generated when the photoresist is heated within the walls constituting the processing chamber.

[0004] [Existing technical documents]

[0005] [Patent Literature]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2022-052854 Summary of the Invention

[0007] [The problem the invention aims to solve]

[0008] Furthermore, in the case of a processing chamber, a structure is sometimes adopted in which an opening is provided in the upper part of the frame housing the hot plate and the opening is blocked by a cover. In a processing chamber with this structure, if the heat insulation is improved, the temperature difference between the lower surface and the upper surface of the cover increases, which may result in thermal warping of the cover. In particular, the larger the device size, the more likely thermal warping will occur. Such thermal warping of the cover may lead to a decrease in the airtightness of the processing chamber or poor opening and closing of the cover, among other problems.

[0009] The purpose of this invention is to provide a technique that can reduce thermal warping of the cover while maintaining high thermal insulation in a substrate heating device.

[0010] [Technical means to solve the problem]

[0011] To address the aforementioned problem, a first embodiment is a substrate heating device, comprising: a hot plate for heating a substrate; a frame portion having an opening at its upper part and capable of receiving the hot plate on its inner side; and a cover portion for closing the opening at the upper part of the frame portion, wherein the cover portion has: a top plate comprising a heat-insulating material; and a reinforcing member having a rib connected to the lower surface of the top plate, the rib protruding downward from the lower surface of the top plate and extending parallel to the lower surface of the top plate.

[0012] The second embodiment is a substrate heating device according to the first embodiment, wherein the ribs comprise fiber-reinforced resin.

[0013] The third embodiment is a substrate heating device according to the first or second embodiment, wherein the rib includes: a first rib extending along a first direction; and a second rib extending along a second direction intersecting the first direction.

[0014] The fourth embodiment is a substrate heating device according to the first or second embodiment, wherein the reinforcing member further has a bottom plate portion, the bottom plate portion is connected to the lower part of the rib portion, and faces the top plate at a distance.

[0015] The fifth embodiment is a substrate heating device according to the fourth embodiment, wherein the lower surface of the base plate is a flat surface.

[0016] The sixth embodiment is a substrate heating device according to the fourth embodiment, wherein the rib and the base plate are integrally formed.

[0017] The seventh embodiment is a substrate heating device according to the fourth embodiment, wherein the reinforcing member has a low expansion portion located further down than the base plate portion, and has a lower coefficient of linear expansion compared to the reinforcing member.

[0018] The eighth embodiment is a substrate heating device according to the fourth embodiment, wherein the cover further includes: a fixing part for fixing the top plate to the reinforcing member, the fixing part including: a spacer located between the top plate and the bottom plate; and a spacer screw that engages with a threaded hole provided on the upper part of the spacer and connects the top plate to the spacer.

[0019] The ninth embodiment is a substrate heating device according to the eighth embodiment, wherein the top plate has: a heat insulation plate comprising heat insulation material; and a back plate located below the heat insulation plate and having higher wear resistance than the heat insulation plate.

[0020] The tenth embodiment is a substrate heating device according to the ninth embodiment, wherein the fixing part further comprises: an annular first collar, fixed between the head of the spacer screw and the spacer, and for the threaded portion of the spacer screw to be inserted, the thickness of the first collar being greater than the thickness of the back panel, forming a gap between the head of the spacer screw and the back panel.

[0021] The eleventh embodiment is a substrate heating device according to the tenth embodiment, wherein the top plate further has a decorative plate, the decorative plate being located above the heat insulation plate and having higher wear resistance than the heat insulation plate.

[0022] The twelfth embodiment is a substrate heating device according to the eleventh embodiment, wherein the fixing part further comprises: a screw that engages with a threaded hole provided on the upper part of the spacer screw; and an annular second collar that is fixed between the head of the screw and the head of the spacer screw and is for the threaded portion of the screw to be inserted, wherein the thickness of the second collar is greater than the thickness of the decorative plate, and a gap is formed between the head of the screw and the decorative plate.

[0023] [The effects of the invention]

[0024] According to the substrate heating apparatus of the first to tenth embodiments, the rigidity of the top plate can be increased by the ribs. Therefore, the thermal warping of the cover can be reduced while maintaining high thermal insulation of the cover.

[0025] According to the substrate heating device of the second embodiment, thermal warping of the cover can be reduced while avoiding excessive weight of the cover.

[0026] According to the substrate heating device of the third embodiment, the rigidity of the top plate can be improved by the cross-section of the ribs compared to the case where they are not cross-sectioned.

[0027] According to the fourth embodiment of the substrate heating device, a space can be formed between the top plate and the reinforcing member through the ribs. This provides an air insulation effect.

[0028] According to the substrate heating apparatus of the fifth embodiment, even if sublimation of coating liquid from the substrate is attached to the lower surface of the base plate, it can be easily removed by wiping or the like.

[0029] According to the substrate heating apparatus of the sixth embodiment, by removing the joints between the parts, the assembly of the reinforcing member can be made easier. Furthermore, by removing the joints between the parts, the durability of the cover can be improved while achieving weight reduction.

[0030] According to the substrate heating device of the seventh embodiment, thermal warping of the bottom plate portion can be further reduced, and therefore, thermal warping of the cover portion can be reduced.

[0031] According to the substrate heating device of the eighth embodiment, the position of the top plate panel relative to the bottom plate portion can be appropriately adjusted while ensuring the spacing between the top plate panel and the bottom plate portion of the reinforcing member by means of spacer screws.

[0032] According to the substrate heating device of the ninth embodiment, the generation of dust and other pollutants from the heat insulation plate can be reduced.

[0033] According to the substrate heating apparatus of the tenth embodiment, since the back panel is not fixed by the spacer screws, even if the back panel undergoes thermal expansion, the deformation of the back panel will not be suppressed by the spacer screws, thus reducing the stress inside the back panel. Therefore, damage such as thermal warping or cracking in the back panel can be reduced.

[0034] According to the substrate heating device of the eleventh embodiment, the generation of dust and other pollutants from the heat insulation plate can be reduced.

[0035] According to the substrate heating apparatus of the twelfth embodiment, since the decorative panel is not fixed by screws, even if the decorative panel undergoes thermal expansion, the deformation of the decorative panel will not be suppressed by the screws, thus reducing the stress inside the decorative panel. Therefore, damage such as thermal warping or cracking in the decorative panel can be reduced. Attached Figure Description

[0036] Figure 1 This is a perspective view of the substrate heating device according to the first embodiment.

[0037] Figure 2 It means along Figure 1 A cross-sectional view of the substrate heating device at the location shown by line II-II.

[0038] Figure 3 It means Figure 1 An exploded perspective view of the structure of the cover shown.

[0039] Figure 4 It is a magnified view showing a portion of the cross-section of the cover.

[0040] Figure 5 This is a diagram showing the cover portion included in the substrate heating device of the second embodiment.

[0041] [Explanation of Symbols]

[0042] 1: Substrate heating device

[0043] 9: Substrate

[0044] 10: Processing Chamber

[0045] 20: Hot plate

[0046] 40: Frame section

[0047] 41: Opening

[0048] 43: Sealing part

[0049] 50, 50a: cover

[0050] 51: Top panel (top plate)

[0051] 53: Reinforced panel (reinforcing component)

[0052] 55: Low-expansion component (low-expansion section)

[0053] 60: Fixing part

[0054] 61: Spacer

[0055] 63: Spacer screws

[0056] 65: Screw

[0057] 67: First collar

[0058] 69: Second collar

[0059] 511: Insulation board

[0060] 513: Decorative panel

[0061] 515: Back panel

[0062] 531: Base Plate

[0063] 533: First rib

[0064] 535: Second rib Detailed Implementation

[0065] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, the constituent elements described in the embodiments are merely examples and are not intended to limit the scope of the invention to these. In the drawings, for ease of understanding, the dimensions or quantities of various parts are sometimes exaggerated or simplified as needed.

[0066] <1. First Implementation>

[0067] Figure 1 This is a perspective view of the substrate heating device 1 according to the first embodiment. Figure 2 It means along Figure 1 A cross-sectional view of the substrate heating device 1 at the location shown by line II-II. Figure 3 It means Figure 1 An exploded perspective view of the structure of the cover 50 shown.

[0068] Furthermore, in some of the accompanying drawings, arrows indicating the orthogonal XYZ coordinate axes are sometimes used to facilitate understanding of the positional relationships of the elements. The XY plane corresponds to the horizontal plane, and the Z axis corresponds to the vertical axis. Additionally, the (-Z) direction corresponds to vertically downward. In the following description, vertically upward is sometimes simply referred to as "up" or "above," and vertically downward is sometimes simply referred to as "down" or "below."

[0069] The substrate heating apparatus 1 heats the substrate 9 while it is housed inside, with a coating liquid such as photoresist coated on its surface, thereby causing the solvent components in the coating liquid to evaporate. The substrate heating apparatus 1 can be used, for example, to form a photoresist film on the surface of the substrate 9. The substrate 9 is, for example, a various substrate to be processed for electronic devices, specifically, a glass substrate for semiconductor wafers, liquid crystal displays or plasma displays, a glass or ceramic substrate for magnetic disks or optical disks, a glass substrate for organic electroluminescence (EL) displays, a glass or silicon substrate for solar cells, a flexible substrate, a printed circuit board, etc.

[0070] The substrate heating device 1 includes a processing chamber 10, a hot plate 20, and a substrate lifting mechanism 30. The hot plate 20 is housed inside the processing chamber 10. The hot plate 20 has a flat upper surface 20a. A heater, such as an electric heating wire, is built into the hot plate 20. By driving the heater, the upper surface 20a is heated to a predetermined temperature.

[0071] The substrate lifting mechanism 30 has multiple lifting pins 31 and a lifting drive unit 33. The multiple lifting pins 31 extend vertically and are distributed horizontally. The multiple lifting pins 31 are inserted into the bottom wall of the frame portion 40 of the processing chamber 10 and into several through holes provided in the hot plate 20, penetrating both the bottom wall of the frame portion 40 and the hot plate 20. The lifting drive unit 33 causes the multiple lifting pins 31 to move up and down integrally. The lifting drive unit 33 is disposed on the outer and lower side of the processing chamber 10. The lifting drive unit 33 may include, for example, a rack and pinion mechanism or a ball screw mechanism including a motor.

[0072] The substrate 9 is supported on the upper ends of a plurality of lifting pins 31. The lifting drive unit 33 moves the plurality of lifting pins 31 between a proximity position of the substrate 9 to the upper surface 20a of the hot plate 20 and an upper position further up than the proximity position. The operation of the lifting drive unit 33 is controlled by a control unit, for example, including a computer.

[0073] The processing chamber 10 is generally rectangular in shape. The processing chamber 10 has a frame portion 40 and a cover portion 50. The frame portion 40 has an opening 41 at the top. A hot plate 20 is housed inside the frame portion 40.

[0074] The cover 50 has a generally plate-like shape that closes the opening 41 at the top of the frame 40. The cover 50 is detachable relative to the top of the frame 40. The cover 50 is placed on the top of the frame 40 via a sealing part 43. The sealing part 43 is a member that blocks the gap between the frame 40 and the cover 50.

[0075] When the cover 50 is removed from the frame 40, the inner surface of the frame 40 is exposed to the outside through the opening 41 of the frame 40. In this state, various maintenance operations such as replacing parts or cleaning inside the frame 40 can be performed through the opening 41 of the frame 40.

[0076] The frame portion 40 has a loading port 45 on the (-Y) side. Additionally, the frame portion 40 has an opening / closing member 47. The opening / closing member 47 moves between a closed position (locked in the loading port 45) and an open position (open in the loading port 45) via an opening / closing drive unit (not shown) including a motor, etc. The operation of this opening / closing mechanism is controlled by a control unit.

[0077] like Figure 2 As shown, the cover 50 has a hollow plate-like structure with internal cavities. The cover 50 has a top panel 51. The top panel 51 is a plate-like member with a quadrilateral shape when viewed from above. The top panel 51 has a heat-insulating plate 511 formed of heat-insulating material (see reference). Figure 3 As insulation materials, for example, fiber-based insulation materials, foamed insulation materials, aerogels, fumed silica, vacuum insulation materials, or combinations thereof can be used. Fiber-based insulation materials include, for example, glass wool, asbestos, cellulose fibers, carbonized cork, wool insulation materials, or wood fibers. Foamed insulation materials include, for example, urethane foam, phenolic foam, polystyrene foam, expandable polystyrene (EPS), flexible elastomeric foam (FEF), or extruded polystyrene (XPS). Aerogels include, for example, silica aerogel, carbon aerogel, or alumina aerogel.

[0078] At least a portion of the outer surface of the insulation panel 511 may be covered with fiber-reinforced resin. Fiber-reinforced resin is a composite material made by combining resin and fibers. As the fiber-reinforced resin, glass fiber reinforced plastic (GFRP), carbon fiber reinforced plastic (CFRP), aramid fiber reinforced plastic (AFRP), natural fiber reinforced plastic, or a combination thereof may be used. Alternatively, multiple types of the same or different fiber-reinforced resins may be laminated on the outer surface of the insulation panel 511. By covering the insulation panel 511 with fiber-reinforced resin, the wear resistance of the insulation panel 511 can be improved. This reduces the dispersion of dust and other particles from the insulation material.

[0079] like Figure 3 As shown, the top panel 51 includes: a heat insulation plate 511, a decorative panel 513 overlapping the upper side of the heat insulation plate 511, and a back panel 515 overlapping the lower side of the heat insulation plate 511. The decorative panel 513 and the back panel 515 are preferably formed from a raw material with higher wear resistance than the heat insulation plate 511, specifically, a carbon fiber plate, etc. Alternatively, the decorative panel 513 and the back panel 515 may not be present.

[0080] Furthermore, in detail, such as Figure 3 As shown, the top panel 51 has a structure in which four blocks are arranged in two rows and two columns. Furthermore, each block has a structure in which a decorative panel 513 and a back panel 515 are superimposed on the heat insulation panel 511. By dividing the top panel 51 into multiple blocks, even if the top panel 51 expands and deforms due to heating, localized deformation can be prevented because each block expands independently. Therefore, the overall deformation of the top panel 51 can be reduced. In addition, even if thermal expansion occurs, stress corresponding to the size of each block will act, thus reducing overall stress. Therefore, damage such as warping or cracking of the top panel 51 can be reduced.

[0081] The cover portion 50 also has a reinforcing panel 53. The reinforcing panel 53 has a base plate portion 531, a plurality of (five in this case) first ribs 533, a plurality of (five in this case) second ribs 535, and an outer frame portion 537. The base plate portion 531 is a plate-shaped member having a quadrilateral shape when viewed from above. Each of the first ribs 533, each of the second ribs 535, and the outer frame portion 537 protrudes upward from the upper surface of the base plate portion 531. The lower surface of the base plate portion 531 is preferably a flat surface.

[0082] Each first rib 533 extends along the X direction (first direction), preferably parallel to the X direction. Each second rib 535 extends along the Y direction (second direction), preferably parallel to the Y direction. That is, the second rib 535 intersects the first rib 533, preferably orthogonal to the first rib 533. The two ends of each first rib 533 and the two ends of each second rib 535 are connected to the outer frame portion 537.

[0083] The outer frame portion 537 has four cylindrical sections that rise upwards from the periphery of the base plate portion 531. The upper part of the outer frame portion 537 is located higher than the upper parts of each of the first ribs 533 and each of the second ribs 535. With the top plate panel 51 mounted on the reinforcing panel 53, the top plate panel 51 is embedded inside the outer frame portion 537. Furthermore, the lower surface of the top plate panel 51 abuts against the upper parts of each of the first ribs 533 and each of the second ribs 535.

[0084] The reinforcing panel 53 is integrally molded from fiber-reinforced resin, for example. That is, the base plate portion 531, the first rib portion 533, the second rib portion 535, and the outer frame portion 537 are integrally molded from fiber-reinforced resin. Carbon fiber reinforced resin can be used as the fiber-reinforced resin. As a molding method for the reinforcing panel 53, resin transfer molding (RTM) can be used, for example.

[0085] Furthermore, it is not necessary for the reinforcing panel 53 to be integrally formed. That is, some of the components in the base plate portion 531, the first rib portion 533, the second rib portion 535, and the outer frame portion 537 may include components different from the remaining parts.

[0086] Figure 4 This is a magnified view showing a portion of the cross-section of the cover 50. For example... Figure 4 As shown, the cover 50 has a plurality of fixing parts 60 for connecting the top panel 51 to the reinforcing panel 53. Each fixing part 60 includes a spacer 61, a spacer screw 63, a screw 65, a first collar 67, and a second collar 69.

[0087] The spacer 61 is provided to properly adjust the position of the top panel 51 relative to the bottom plate portion 531 to ensure the spacing between the top panel 51 and the bottom plate portion 531 of the reinforcing panel 53 in the Z direction. The spacer 61 is fixed to the bottom plate portion 531 of the reinforcing panel 53 by means of an adhesive or the like. Alternatively, the spacer 61 may also be fixed to the first rib 533 or the second rib 535 by means of an adhesive or the like.

[0088] In the illustrated example, one spacer 61 is disposed on each of the +Y and -Y sides of the first rib 533. However, the placement of the spacer 61 is not limited to this. In addition, the spacer 61 is designed as a different component from the reinforcing panel 53, but it may also be integrally formed together with the reinforcing panel 53, for example.

[0089] The spacer 61 is located between the top panel 51 (specifically the back panel 515) and the bottom plate portion 531 of the reinforcing panel 53, and is held between the top panel 51 and the bottom plate portion 531. In the Z direction, the size of the spacer 61 is approximately the same as the size of the first rib 533 and the second rib 535.

[0090] The spacer screw 63 has a head 631 and a threaded portion 633. In the Z-direction, the head 631 of the spacer screw 63 is located between the decorative panel 513 and the back panel 515. In the Z-direction, the size of the head 631 of the spacer screw 63 is approximately the same as the size of the heat insulation plate 511. A threaded hole is provided on the upper part of the spacer 61, which engages with the threaded portion 633 of the spacer screw 63. The threaded portion 633 of the spacer screw 63 passes through the back panel 515 and is fixed in the threaded hole of the spacer 61. The head 631 is inserted into a through hole provided on the heat insulation plate 511. The spacer screw 63 ensures the spacing between the decorative panel 513 and the back panel 515 in the Z-direction. Thus, the position of the decorative panel 513 relative to the back panel 515 is appropriately adjusted. In addition, in the Z-direction, the position of the back panel 515 is limited by the head 631 of the spacer screw 63 and the spacer 61.

[0091] The screw 65 has a head 651 and a threaded portion 653. A threaded hole is provided on the upper part of the spacer screw 63, engaging with the threaded portion 653 of the screw 65. The threaded portion 653 of the screw 65 passes through a decorative plate 513 and is fixed to the threaded hole of the spacer screw 63. The decorative plate 513 is disposed between the head 651 of the screw 65 and the head 631 of the spacer screw 63.

[0092] The first collar 67 is a ring-shaped component when viewed from above. The first collar 67 is clamped and fixed between the head 631 of the spacer screw 63 and the spacer 61 in the Z-direction. In the Z-direction, the thickness of the first collar 67 is slightly greater than the thickness of the back panel 515. Therefore, with the spacer screw 63 fixed to the spacer 61, a slight gap is formed between the head 631 and the back panel 515 in the Z-direction.

[0093] The second collar 69 is a ring-shaped component when viewed from above. The second collar 69 is clamped and fixed between the head 651 of the screw 65 and the head 631 of the spacer screw 63 in the Z-direction. In the Z-direction, the thickness of the second collar 69 is slightly greater than the thickness of the decorative panel 513. Therefore, with the screw 65 fixed to the spacer screw 63, a slight gap is formed between the head 651 and the decorative panel 513 in the Z-direction.

[0094] As described above, the substrate heating device 1 of this embodiment includes a hot plate 20, a frame portion 40, and a cover portion 50. The hot plate 20 heats the substrate 9. The frame portion 40 has an opening 41 at its upper part. The frame portion 40 can accommodate the hot plate 20 on its inner side. The cover portion 50 closes the opening 41 at the upper part of the frame portion 40. The frame portion 40 has a top plate panel 51 as a top plate and a reinforcing panel 53 as a reinforcing member. The top plate panel 51 includes a heat-insulating material. The reinforcing panel 53 has a first rib 533 and a second rib 535 connected to the lower surface of the top plate panel 51. The first rib 533 and the second rib 535 protrude downward from the lower surface of the top plate panel 51 and extend parallel to the lower surface of the top plate panel 51. According to the above structure, the rigidity of the top plate panel 51 can be improved by the first rib 533 and the second rib 535. Therefore, the thermal warping of the cover 50 can be reduced while maintaining high thermal insulation properties.

[0095] The first rib 533 and the second rib 535 comprise fiber-reinforced resin. According to this structure, thermal warping of the cover 50 can be reduced while avoiding excessive weight.

[0096] The ribs include a first rib 533 extending along a first direction (X direction) and a second rib 535 extending along a second direction intersecting the first direction (here, the Y direction orthogonal to the X direction). According to the structure, the rigidity of the top panel 51 can be further improved by the intersection of the bottom plate portion 531 and the second rib 535 compared to the case where they do not intersect.

[0097] The reinforcing panel 53 has a base plate portion 531. The base plate portion 531 is connected to the lower portions of the first rib 533 and the second rib 535. The base plate portion 531 faces the top panel 51 at a distance in the Z direction. According to this structure, a space can be formed between the top panel 51 and the reinforcing panel 53 through the first rib 533 and the second rib 535. This provides an air insulation effect.

[0098] The lower surface of the base plate portion 531 is a flat surface. According to the above structure, even if sublimation of the coating liquid from the substrate 9 adheres to the lower surface of the base plate portion 531, it can be easily removed by wiping or the like.

[0099] The first rib 533, the second rib 535, and the base plate 531 are integrally formed. According to this structure, by removing the joints between the parts, the assembly of the reinforced panel 53 can be easily performed. Furthermore, by removing the joints between the parts, the durability of the cover 50 can be improved while achieving weight reduction.

[0100] The cover 50 also includes a fixing portion 60 for fixing the top panel 51 to the reinforcing panel 53. The fixing portion 60 includes a spacer 61 and a spacer screw 63. The spacer 61 is located between the top panel 51 and the bottom plate portion 531. The spacer screw 63 engages with a threaded hole located on the upper part of the spacer 61. The spacer screw 63 connects the top panel 51 to the spacer 61. According to this structure, the position of the top panel 51 relative to the bottom plate portion 531 can be appropriately adjusted while ensuring the spacing between the top panel 51 and the bottom plate portion 531 of the reinforcing panel 53 using the spacer screw 63.

[0101] The top panel 51 has a heat insulation plate 511 and a back panel 515. The heat insulation plate 511 includes heat insulation material. The back panel 515 is located below the heat insulation plate 511. The back panel 515 has higher wear resistance than the heat insulation plate 511. According to the above structure, the generation of dust and the like from the heat insulation plate 511 can be reduced.

[0102] The fixing part 60 also has a first collar 67. The first collar 67 is fixed between the head 631 of the spacer screw 63 and the spacer 61. The thickness of the first collar 67 is greater than the thickness of the back panel 515. The first collar 67 has an annular shape for the threaded portion 633 of the spacer screw 63 to be inserted. A gap is formed between the head 631 of the spacer screw 63 and the back panel 515. According to the above structure, since the back panel 515 is not fixed by the spacer screw 63, even if the back panel 515 undergoes thermal expansion, the deformation of the back panel 515 will not be suppressed by the spacer screw 63, thus reducing the internal stress of the back panel 515. Therefore, damage such as thermal warping or cracking of the back panel 515 can be reduced.

[0103] The top panel 51 also has a decorative panel 513. The decorative panel 513 is located above the insulation panel 511 and has higher wear resistance than the insulation panel 511. According to the above structure, the generation of dust and the like from the insulation panel 511 can be reduced.

[0104] The fixing part 60 includes a screw 65 and a second collar 69. The screw 65 engages with a threaded hole located on the upper part of the spacer screw 63. The second collar 69 is fixed between the head 651 of the screw 65 and the head 631 of the spacer screw 63. The thickness of the second collar 69 is greater than the thickness of the decorative plate 513. The second collar 69 has an annular shape for the threaded portion 653 of the screw 65 to be inserted. A gap is formed between the head 651 of the screw 65 and the decorative plate 513. According to this structure, since the decorative plate 513 is not fixed by the screw 65, even if the decorative plate 513 thermally expands, the deformation of the decorative plate 513 will not be suppressed by the screw 65, thus reducing the internal stress of the decorative plate 513. Therefore, damage such as thermal warping or cracking of the decorative plate 513 can be reduced.

[0105] <2. Second Implementation>

[0106] Next, the second embodiment will be described. Furthermore, in the following description, elements having the same function as those already described are sometimes marked with the same symbols or have additional letter symbols, and detailed descriptions are omitted.

[0107] Figure 5 This figure shows the cover portion 50a included in the substrate heating device 1 according to the second embodiment. Similar to the cover portion 50, the cover portion 50a includes a top plate panel 51 and a reinforcing plate panel 53. However, the cover portion 50a also includes a low-expansion member 55. The low-expansion member 55 is located further below the reinforcing plate panel 53, and in this embodiment, it engages with the lower surface of the bottom plate portion 531 of the reinforcing plate panel 53.

[0108] The coefficient of linear expansion of the low-expansion member 55 is lower than that of the reinforcing panel 53. For example, a prepreg (carbon fiber sheet pre-impregnated with resin) can be used as the low-expansion member 55. Alternatively, the low-expansion member 55 can also be a coating layer formed by applying a coating agent containing resin or the like. The coating agent is appropriately selected based on the surface material of the base plate portion 531. For example, if the reinforcing panel 53 is a flame-retardant fiber-reinforced resin, a coating agent containing brominated bisphenol A type epoxy acrylate resin can be used.

[0109] Thus, the reinforcing panel 53 of the cover portion 50a has a low-expansion member 55 located further down than the base plate portion 531 and having a lower coefficient of linear expansion compared to the reinforcing panel 53. According to this structure, thermal warping of the base plate portion 531 can be actively reduced, and therefore, thermal warping of the cover portion 50 can be reduced.

[0110] The present invention has been described in detail, but the description is exemplary in all respects and the invention is not limited thereto. It can be interpreted that numerous variations not illustrated can be contemplated without departing from the scope of the invention. The structures described in the various embodiments and variations may be appropriately combined or omitted as long as they do not contradict each other.

Claims

1. A substrate heating device, characterized by, The substrate heating device includes: a hot plate that heats a substrate; a frame portion that has an opening in an upper portion and can accommodate the hot plate inside; a cover portion that closes the opening in the upper portion of the frame portion, wherein the cover portion has: a top plate that includes a heat insulating material; and a reinforcing member that has a rib portion coupled to a lower surface of the top plate, the rib portion protrudes downward from the lower surface of the top plate and extends in parallel with the lower surface of the top plate, the reinforcing member further has: a bottom plate portion coupled to a lower portion of the rib portion and facing the top plate at a spaced interval, a lower surface of the bottom plate portion is a flat surface, the rib portion and the bottom plate portion are integrally formed, the cover portion further has a fixing portion that fixes the top plate to the reinforcing member, the fixing portion has: a spacer between the top plate and the bottom plate portion; and a spacer screw that engages with a threaded hole provided in an upper portion of the spacer and couples the top plate to the spacer, the top plate has: a heat insulating plate that includes the heat insulating material; and a back plate that is located on a lower side of the heat insulating plate and has higher wear resistance than the heat insulating plate, the fixing portion further has: a first annular collar that is fixed between a head portion of the spacer screw and the spacer and into which a threaded portion of the spacer screw is inserted, a thickness of the first annular collar is greater than a thickness of the back plate, a gap is formed between the head portion of the spacer screw and the back plate, the top plate further has: a decorative plate that is located on an upper side of the heat insulating plate and has higher wear resistance than the heat insulating plate, the fixing portion further has: a screw that engages with a threaded hole provided in an upper portion of the spacer screw; and a second annular collar that is fixed between a head portion of the screw and a head portion of the spacer screw and into which a threaded portion of the screw is inserted, a thickness of the second annular collar is greater than a thickness of the decorative plate, a gap is formed between the head portion of the screw and the decorative plate.

2. The substrate heating device according to claim 1, wherein the rib portion includes a fiber-reinforced resin.

3. The substrate heating device according to claim 1 or 2, wherein the rib portion includes: a first rib portion that extends in a first direction; and a second rib portion that extends in a second direction that intersects the first direction.

4. The substrate heating device according to claim 1 or 2, wherein the reinforcing member has a low expansion portion, the low expansion portion is located at a lower side than the bottom plate portion and has a lower coefficient of linear expansion than the reinforcing member. ​ ​

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