Heating device

Abstract

A heating device according to the present disclosure has a heating plate and a plurality of heaters. The heating plate has a heating surface and a plurality of recess sections formed in a rear surface on the opposite side of the heating surface. The plurality of heaters are respectively inserted into the plurality of recess sections. Wiring parts having planarly extending patterns are respectively located inside the plurality of heaters. In addition, the orientation of the pattern surface of a wiring part in at least one heater among the plurality of heaters is different from the orientation of the pattern surface in another heater adjacent to said at least one heater.

Description

Technical Field

[0001] The disclosed embodiments relate to a heating device.

Background Art

[0002] Patent Document 1 discloses a heating device in which a plurality of heaters are arranged in parallel with the heating surface of a mold by inserting the plurality of heaters into a plurality of holes formed in the side surface of the mold.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] A heating device according to an aspect of an embodiment includes a heating plate and a plurality of heaters. The heating plate has a heating surface, and a plurality of recesses are formed on the back surface opposite to the heating surface. The plurality of heaters are respectively inserted into the plurality of recesses. Inside each of the plurality of heaters, a wiring portion having a pattern that spreads planar is located. Further, at least one of the plurality of heaters has a direction of the pattern surface of the wiring portion different from the direction of the pattern surface of the other heaters adjacent to the heater.

Brief Description of the Drawings

[0005]

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[0006] Hereinafter, embodiments for implementing the heating device according to the present disclosure (hereinafter referred to as "embodiments") will be described in detail with reference to the drawings. Note that the heating device according to the present disclosure is not limited by this embodiment. Also, each embodiment can be appropriately combined within a range that does not conflict with the processing content. In addition, in the following embodiments, the same parts are denoted by the same reference numerals, and redundant explanations are omitted.

[0007] In addition, in the embodiments shown below, expressions such as "constant", "orthogonal", "perpendicular", or "parallel" may be used, but these expressions do not necessarily require strict "constant", "orthogonal", "perpendicular", or "parallel". That is, each of the above expressions allows for deviations such as manufacturing accuracy and installation accuracy.

[0008] Also, each of the figures referred to below is schematic for convenience of explanation. Therefore, details may be omitted, and the dimensional ratios do not necessarily match the actual ones.

[0009] In addition, in each of the drawings referred to below, for ease of explanation, an orthogonal coordinate system may be shown that defines the X-axis direction, Y-axis direction, and Z-axis direction that are orthogonal to each other, with the positive Z-axis direction being the vertically upward direction.

[0010] In the above-described prior art, there is still room for further improvement in terms of improving the heat uniformity within the heating surface. Therefore, there is an expectation to provide a heating device capable of improving the heat uniformity within the heating surface.

[0011] FIG. 1 is a side view of the heating device 100 according to the embodiment as viewed from the negative Y-axis direction. FIG. 2 is a plan view of the heating device 100 according to the embodiment as viewed from the positive Z-axis direction. FIG. 3 is a side cross-sectional view taken along the arrow III-III shown in FIG. 2.

[0012] Hereinafter, when the heating device 100 is brought into contact with the object to be heated, the surface located on the object-to-be-heated side is defined as the "upper surface", and the surface located on the side opposite to the object to be heated is defined as the "lower surface". Note that the heating device 100 is not limited to this, and may be used, for example, with the top and bottom reversed, or in any orientation.

[0013] The heating device 100 shown in FIG. 1 includes a heating plate 110, a plurality of heaters 120, and a fixing plate 130.

[0014] The heating plate 110 is, for example, a plate-like member made of metal and has an upper surface 110a that can come into contact with the object to be heated. That is, the upper surface 110a of the heating plate 110 serves as the heating surface for heating the object to be heated. The upper surface 110a is used, for example, for heating a mold as an example of the object to be heated. A plurality of recesses 113 (see FIGS. 2 and 3) are formed in the lower surface 110b on the side opposite to the heating surface of the heating plate 110.

[0015] The heating plate 110 includes a first plate member 111, a second plate member 112, and a heat insulating member 115.

[0016] The first plate member 111 is a plate-like member having the upper surface 110a of the heating plate 110 which is the heating surface. The first plate member 111 is joined to the second plate member 112 by a joining member 114 (see FIGS. 2 and 3) such as a bolt with the heat insulating member 115 disposed between the first plate member 111 and the second plate member 112. That is, the lower surface 111a on the side opposite to the upper surface 110a of the first plate member 111 is the joining surface joined to the second plate member 112. A plurality of recesses 111b (see FIG. 3) are formed in the lower surface 111a on the side opposite to the heating surface of the first plate member 111.

[0017] The second plate member 112 is a plate-like member having an upper surface 112a serving as a surface to be joined to the joining surface of the first plate member 111 and a lower surface 110b located on the opposite side of the upper surface 112a. A plurality of through holes 112b (see FIG. 3) are formed in the second plate member 112 at positions corresponding to the plurality of recesses 111b.

[0018] The heat insulating member 115 is inserted between the first plate member 111 and the second plate member 112. The heat insulating member 115 is, for example, a sheet-like member made of a heat insulating fiber having gaps inside, such as porous or cotton, and has a function of restricting heat transfer from the first plate member 111 side to the second plate member 112 side. A plurality of through holes 115a (see FIG. 3) are formed in the heat insulating member 115 at positions corresponding to the plurality of recesses 111b.

[0019] The material of the heat insulating member 115 is preferably, for example, a heat insulating ceramic or glass. As the material of the heat insulating member 115, for example, oxide ceramics such as aluminum oxide, nitride ceramics such as silicon nitride and aluminum nitride, or carbide ceramics such as silicon carbide can be used.

[0020] Each of the plurality of recesses 113 is formed by each of the plurality of through holes 112b, each of the plurality of through holes 115a, and the plurality of recesses 111b. That is, the inner surfaces of the respective through holes 112b, the inner surfaces of the respective through holes 115a, and the inner surfaces of the respective recesses 111b form the inner surface of each recess 113, and the bottom surface of each recess 111b forms the bottom surface of each recess 113. Then, the tip portions 120a of the plurality of heaters 120 are located within the plurality of recesses 111b in a state where the plurality of heaters 120 are respectively inserted into the plurality of recesses 113.

[0021] By positioning the tip portions 120a of the plurality of heaters 120 within the plurality of recesses 111b, for example, when each tip portion 120a of the plurality of heaters 120 has a maximum heat generation point where the temperature is maximum, the maximum heat generation point can be brought close to the upper surface 110a of the heating plate 110 which is the heating surface. As a result, the heating device 100 according to the embodiment can efficiently heat the upper surface 110a of the heating plate 110 which is the heating surface. Also, by positioning the tip portions 120a of the plurality of heaters 120 within the plurality of recesses 111b, the maximum heat generation point can be moved away from the base end portions 120b of the plurality of heaters 120. As a result, it becomes difficult for the heat from the maximum heat generation point to be transmitted to the anode side lead electrode 123 and the cathode side lead electrode 124 provided at the base end portions 120b of the plurality of heaters 120. Therefore, the heating device 100 according to the embodiment can improve the effect of preventing the deterioration of the anode side lead electrode 123 and the cathode side lead electrode 124.

[0022] Note that each tip portion 120a of the plurality of heaters 120 may or may not be in contact with the bottom surface of each recess 111b.

[0023] The fixing plate 130 is, for example, a plate-like member made of metal. A plurality of heaters 120 are fixed to the fixing plate 130.

[0024] The fixing plate 130 is arranged separated from the second plate member 112. The fixing plate 130 is connected to the second plate member 112 by a connecting member 131 such as a bolt, for example, with a gap formed between the fixing plate 130 and the heating plate 110. For example, the fixing plate 130 is connected to the second plate member 112 by a plurality (here, four) of connecting members 131.

[0025] The connecting member 131 has a tip portion 131a formed with an external thread that can be fitted into the internal thread of the screw hole 112c of the second plate member 112. The tip portion 131a of the connecting member 131 extends with a length that fits into the screw hole 112c of the second plate member 112 and does not penetrate the heat insulating member 115 in the direction of the first plate member 111. In the present embodiment, the tip portion 131a of the connecting member 131 extends to a position reaching from the lower surface 110b to the upper surface 112a of the second plate member 112 in the screw hole 112c and is in contact with the surface of the heat insulating member 115 exposed from the screw hole 112c.

[0026] In this way, by extending the tip portion 131a of the connecting member 131 so as not to penetrate the heat insulating member 115 in the direction of the first plate member 111, contact between the connecting member 131 and the first plate member 111 can be avoided. As a result, heat conduction from the first plate member 111 having the upper surface 110a as the heating surface to the connecting member 131 is reduced.

[0027] Further, by bringing the tip portion 131a of the connecting member 131 into contact with the surface of the heat insulating member 115, the positions of the tip portions 131a of the plurality of connecting members 131 are aligned on the same plane as the surface of the heat insulating member 115. Thereby, since the length of the heat transfer path from the first plate member 111 to the tip portions 131a of the plurality of connecting members 131 is made uniform, the heat uniformity of the first plate member 111 is improved.

[0028] Further, the connecting member 131 has a spacer member 140 on the outer periphery of the portion located between the fixed plate 130 and the second plate member 112. The spacer member 140 has a cylindrical shape surrounding the outer periphery of the portion of the connecting member 131 located between the fixed plate 130 and the second plate member 112 and is in contact with the fixed plate 130 and the second plate member 112. A gap may or may not be provided between the inner peripheral surface of the spacer member 140 and the outer peripheral surface of the connecting member 131. By surrounding the outer periphery of the connecting member 131 with the cylindrical spacer member 140, it becomes difficult for the heat of the connecting member 131 to be released to the space around the connecting member 131.

[0029] As the material of the spacer member 140, for example, a metal such as stainless steel can be used. Thereby, the durability of the spacer member 140 can be improved, and the distance between the fixed plate 130 and the second plate member 112 can be maintained constant.

[0030] As shown in FIG. 3, the second plate member 112 is joined to the first plate member 111 by a joining member 114 such as a bolt in a state where a heat insulating member 115 is disposed between the first plate member 111 and the second plate member 112. For example, the second plate member 112 is joined to the first plate member 111 by a plurality (four in the example shown in FIG. 2) of joining members 114.

[0031] The plurality of heaters 120 are respectively inserted into the plurality of recesses 113. Thereby, the plurality of heaters 120 are arranged so as to be perpendicular to the upper surface 110a of the heating plate 110 which is the heating surface. By arranging the plurality of heaters 120 perpendicular to the upper surface 110a (heating surface) of the heating plate 110 in this way, the variation in the distance between the plurality of heaters 120 and the heating surface is reduced, so that the heat uniformity within the plane of the heating surface can be improved. Further, a temperature distribution occurs in the longitudinal direction of the heater 120. On the other hand, by arranging the plurality of heaters 120 perpendicular to the heating surface of the heating plate 110, it is possible to make it difficult to generate a temperature difference due to the temperature distribution of the heater 120 between the central portion and the outer peripheral portion of the upper surface 110a.

[0032] As shown in FIG. 2, the plurality of recesses 113 are arranged in parallel with the sides of the heating plate 110. Specifically, the heating plate 110 has sides parallel to the X axis and sides parallel to the Y axis. And the plurality of recesses 113 are located in a matrix parallel to the X axis and the Y axis.

[0033] Here, the configuration of the heater 120 will be described with reference to FIGS. 4 and 5. FIG. 4 is a cross-sectional view of the heater 120 according to the embodiment. Further, FIG. 5 is a cross-sectional view taken along the line V-V shown in FIG. 4.

[0034] As shown in FIG. 4, the heater 120 according to the embodiment includes a heater main body 121, a fixing member 122, an anode side lead electrode 123, and a cathode side lead electrode 124.

[0035] The heater main body 121 is a ceramic heater. The heater main body 121 is rod-shaped and has a tip portion 120a and a base end portion 120b. The heater main body 121 is inserted into the recess 113 from the tip portion 120a side.

[0036] The heater main body 121 has a heating resistor 125 inside the ceramic body. By using the heater main body 121 as a ceramic heater, it is less likely that sticking occurs between the heating plate 110 made of metal and the heater main body 121. As a result, problems such as the heater 120 becoming non-replaceable due to the heater main body 121 sticking to the heating plate 110 are less likely to occur.

[0037] As shown in FIGS. 4 and 5, the heating resistor 125 (an example of a wiring portion) has a pattern (here, a substantially U-shaped pattern) that spreads planar inside the heater main body 121. Specifically, the heating resistor 125 is located inside the heater main body 121 and has two extending portions 125a that extend along the longitudinal direction (here, the Z-axis direction) of the heater main body 121, and a turning-back portion 125b that connects the two extending portions 125a on the tip side of the heater main body 121.

[0038] Hereinafter, as shown in FIG. 5, a surface of the heating resistor 125 that is orthogonal to a plane (in FIG. 5, the XZ plane) in which the pattern shape of the heating resistor 125 spreads is described as the pattern surface S of the heating resistor 125. The pattern surface S faces a direction orthogonal to the longitudinal direction (Z-axis direction) of the heater main body 121. There is no front and back distinction for the heating resistor 125, and either surface of the two surfaces of the heating resistor 125 may be defined as the pattern surface S. In other words, both surfaces of the heating resistor 125 may be defined as the pattern surface S.

[0039] The length of the heater main body 121, that is, the length of the ceramic body, can be, for example, about 1 mm or more and 200 mm or less. Further, the outer dimension of the ceramic body can be, for example, about 0.5 mm or more and 100 mm or less.

[0040] The shape of the heater main body 121, that is, the shape of the ceramic body, is, for example, cylindrical as shown in FIG. 5. The shape of the heater main body 121 is not limited to a cylindrical shape, and may be, for example, an elliptical columnar shape or a prismatic shape. The material of the ceramic body is, for example, a ceramic having insulating properties. As the material of the ceramic body, for example, oxide ceramics, nitride ceramics, carbide ceramics, or the like can be used.

[0041] The heating resistor 125 is a member that generates heat when an electric current flows through it. The heating resistor 125 is connected to the coil portion 123a of the anode side lead electrode 123, which will be described later, at one end. Further, the heating resistor 125 is connected to the coil portion 124a of the cathode side lead electrode 124, which will be described later, at the other end.

[0042] The heating resistor 125 may include, for example, a high-resistance conductor containing tungsten or molybdenum. The dimensions of the heating resistor 125 can be, for example, a width of 0.1 mm or more and 5 mm or less, a thickness of 0.05 mm or more and 0.3 mm or less, and a total length of 1 mm or more and 500 mm or less. Further, the heating resistor 125 may be, for example, a conductive ceramic containing tungsten carbide. In this case, the difference in thermal expansion between the ceramic body and the heating resistor 125 can be reduced. Thereby, the thermal stress between the ceramic body and the heating resistor 125 can be reduced. As a result, the durability of the heater main body 121 can be enhanced.

[0043] The fixing member 122 has a cylindrical shape surrounding the peripheral surface of the heater main body 121. The fixing member 122 has, for example, a first member 122a and a second member 122b.

[0044] On the outer peripheral surface of the first member 122a, there is a male thread 122c. The material of the first member 122a is, for example, a heat-resistant metal material. As the material of the fixing member 122, for example, an alloy containing Fe or Ni can be used. Specifically, the fixing member 122 can be made of stainless steel, an Fe-Ni-Co alloy, a Ni-based heat-resistant alloy, or the like.

[0045] The second member 122b is located between the first member 122a and the coil portion 124a of the cathode-side lead electrode 124. The material of the second member 122b is, for example, an insulating ceramic. As the material of the second member 122b, for example, alumina or silicon nitride may be used.

[0046] The anode-side lead electrode 123 and the cathode-side lead electrode 124 are fixed to the peripheral surface of the heater body 121. One end of the anode-side lead electrode 123 is connected to an external power source (not shown), and the other end is electrically connected to the heating resistor 125. Also, one end of the cathode-side lead electrode 124 is connected to an external power source (not shown), and the other end is electrically connected to the heating resistor 125.

[0047] The anode-side lead electrode 123 and the cathode-side lead electrode 124 are, for example, wire materials containing a metal material such as nickel, iron, or a Ni-based heat-resistant alloy. The cross-section of the anode-side lead electrode 123 and the cathode-side lead electrode 124 may be, for example, circular, elliptical, or rectangular. The outer diameter of the anode-side lead electrode 123 and the cathode-side lead electrode 124 may be, for example, 0.5 or more and 2.0 mm or less.

[0048] The anode-side lead electrode 123 has a coil portion 123a and a terminal portion 123b. The coil portion 123a is a portion of the anode-side lead electrode 123 that is spirally wound along the circumferential surface of the heater body 121, and is electrically connected to one end of the heating resistor 125. The terminal portion 123b is a portion of the anode-side lead electrode 123 that is drawn out from the coil portion 123a to the outside of the heater body 121. The terminal portion 123b extends from the rear end of the heater body 121 outward in the longitudinal direction of the heater body 121 (here, the negative Z-axis direction).

[0049] The cathode-side lead electrode 124 has a coil portion 124a and a terminal portion 124b. The coil portion 124a is a portion of the cathode-side lead electrode 124 that is spirally wound along the circumferential surface of the heater body 121, and is electrically connected to the other end of the heating resistor 125. The terminal portion 124b is a portion of the cathode-side lead electrode 124 that is drawn out from the coil portion 124a. The terminal portion 124b extends from the circumferential surface of the heater body 121 radially outward of the heater body 121 (here, the positive Y-axis direction).

[0050] As described above, the lead electrodes of the heater 120 (the anode-side lead electrode 123 and the cathode-side lead electrode 124) have the coil portions 123a and 124a located along the circumferential surface of the heater body 121, and the terminal portions 123b and 124b drawn out from the coil portions 123a and 124a. In the heater 120 configured in this way, since the coil portions 123a and 124a function as springs, stress is less likely to concentrate. Therefore, the heater 120 configured in this way has high durability.

[0051] Here, an example in which the anode-side lead electrode 123 is located on the rear end side of the heater body 121 with respect to the cathode-side lead electrode 124 has been described. However, the positional relationship between the anode-side lead electrode 123 and the cathode-side lead electrode 124 may be reversed. That is, the lead electrode provided at the position of the anode-side lead electrode 123 shown in FIG. 4 may be the cathode-side lead electrode 124. Also, the lead electrode provided at the position of the cathode-side lead electrode 124 shown in FIG. 4 may be the anode-side lead electrode 123.

[0052] The plurality of heaters 120 included in the heating device 100 are inserted into a plurality of recesses 113 formed in the lower surface 110b of the heating plate 110.

[0053] Note that the heating device 100 has a spacer member 170 on the outer periphery of the portion that penetrates the heat insulating member 115 of the joining member 114. The spacer member 170 has a cylindrical shape that surrounds the portion that penetrates the heat insulating member 115 of the joining member 114 and is in contact with the first plate member 111 and the second plate member 112. A gap may or may not be provided between the inner peripheral surface of the spacer member 170 and the outer peripheral surface of the joining member 114. By surrounding the outer periphery of the joining member 114 with the cylindrical spacer member 170, it becomes difficult for the heat of the joining member 114 to be transmitted to the heat insulating member 115.

[0054] The spacer member 170 is preferably made of, for example, a ceramic having relatively high heat insulation. As the material of the spacer member 170, for example, oxide ceramics, nitride ceramics, carbide ceramics, or the like can be used. Thereby, heat transfer from the joining member 114 to the heat insulating member 115 is further reduced.

[0055] FIG. 6 is a schematic diagram for explaining an example of the orientation of the pattern surface S of the heating resistor 125 included in the plurality of heaters 120.

[0056] As shown in FIG. 6, in the heating device 100 according to the embodiment, for at least one heater 120 among the plurality of heaters 120, the orientation of the pattern surface S of the heating resistor 125 is different from the orientation of the pattern surface S in another heater 120 adjacent to that heater 120.

[0057] For example, among the plurality of heaters 120_1 to 120_9 shown in FIG. 6, the orientation of the pattern surface S5 of the heater 120_5 is different from the orientation of the pattern surface S6 of the heater 120_6 adjacent to the heater 120_5.

[0058] A ceramic heater incorporating a heating resistor with a planar pattern is more likely to exhibit anisotropy in the temperature distribution compared to a cartridge heater incorporating a coiled heating resistor with a three-dimensional pattern. Therefore, when arranging a plurality of ceramic heaters on a heating plate, if the orientations of the pattern surfaces of the heating resistors are aligned, anisotropy may occur in the in-plane temperature distribution of the heating surface. That is, the heat uniformity of the heating surface may decrease.

[0059] In contrast, in the heating device 100 according to the embodiment, since the orientations of the pattern surfaces S of two adjacent heaters 120 are misaligned, anisotropy is less likely to occur in the in-plane temperature distribution of the heating surface. Therefore, the heating device 100 according to the embodiment can improve the heat uniformity in the plane of the heating surface.

[0060] Note that in the heating device 100 according to the embodiment, at least in two adjacent heaters 120 among the plurality of heaters 120 included in the heating device 100, it is sufficient that the orientations of the pattern surfaces S are different. Preferably, in the heating device 100, among two heaters 120 out of the plurality of heaters 120 (here, heaters 120_2, 120_3, 120_5, 120_6) located at the central portion of the upper surface 110a of the heating plate 110 which is the heating surface, the orientations of the pattern surfaces S are different.

[0061] Here, in the arrangement directions (X-axis direction and Y-axis direction) of the plurality of heaters 120, the heater 120 adjacent to that heater 120 is defined as "the heater 120 adjacent to that heater 120". Not limited to this, the heater 120 adjacent to that heater 120 in a direction oblique to the arrangement direction of the plurality of heaters 120 (for example, directions of 45 degrees, 135 degrees, 225 degrees, 315 degrees as seen from that heater 120) may also be included as "the heater 120 adjacent to that heater 120".

[0062] In order to produce an effect of making it difficult for anisotropy to occur in the in-plane temperature distribution of the heating surface, in order to avoid the pattern surfaces S of a plurality of adjacent heaters 120 being on the same plane, it is preferable that the orientations of the pattern surfaces S differ by at least 10 degrees or more.

[0063] Further, in the heating device 100 according to the embodiment, the orientation of the pattern surface S of at least one heater 120 among the plurality of heaters 120 may be different from the orientation of the pattern surface S of any of the two or more other heaters 120 adjacent to the heater 120 so as to surround the heater 120.

[0064] For example, in the example shown in FIG. 6, around the heater 120_5, heaters 120_2, 120_4, 120_6, 120_8 are adjacent to the heater 120_5 so as to surround the heater 120_5. In this case, the orientation of the pattern surface S5 of the heater 120_5 is different from the orientation of any of the pattern surfaces S2, S4, S6, S8 of the heaters 120_2, 120_4, 120_6, 120_8.

[0065] When configured in this way, the effect of making it difficult for anisotropy to occur in the in-plane temperature distribution of the heating surface can be further enhanced. Therefore, the heating device 100 having such a configuration can further improve the heat uniformity in the in-plane of the heating surface.

[0066] Here, in the arrangement directions (X-axis direction and Y-axis direction) of the plurality of heaters 120, the heaters 120_2, 120_4, 120_6, 120_8 adjacent to the heater 120_5 are described as "two or more other heaters 120 adjacent to the heater 120 so as to surround the heater 120". However, not limited to this, the heaters 120_1, 120_3, 120_7, 120_9 adjacent to the heater 120_5 in the diagonal direction (for example, the 45-degree, 135-degree, 225-degree, 315-degree directions as viewed from the heater 120) with respect to the arrangement direction of the plurality of heaters 120 may also be included in the "two or more other heaters 120 adjacent to the heater 120 so as to surround the heater 120". That is, the orientation of the pattern surface S5 of the heater 120_5 may be different from the orientations of any of the pattern surfaces S1 to S4, S6 to S9 of the heaters 120_1 to 120_4, 120_6 to 120_9.

[0067] Further, at least one of the plurality of heaters 120 may have the orientation of the pattern surface S orthogonal to the orientation of the pattern surface S in the other heaters 120 adjacent to the heater 120.

[0068] For example, in the example shown in FIG. 6, the pattern surface S8 of the heater 120_8 is orthogonal to the pattern surface S9 of the heater 120_9 adjacent to the heater 120_8. Also, the pattern surface S1 of the heater 120_1 is orthogonal to the pattern surface S2 of the heater 120_2 adjacent to the heater 120_1, and is also orthogonal to the pattern surface S4 of the heater 120_4 adjacent to the heater 120_1.

[0069] In such a configuration, the anisotropy of the temperature caused by the pattern shape of the heating resistor 125 can be most effectively canceled. Therefore, the heating device 100 having such a configuration can further improve the heat uniformity within the heating surface.

[0070] FIG. 7 is a schematic diagram for explaining another example of the orientation of the pattern surface S of the heating resistor 125 included in the plurality of heaters 120.

[0071] As shown in FIG. 7, in all the heaters 120 included in the heating device 100 according to the embodiment, the directions of the pattern surfaces S of adjacent heaters 120 may be different. By adopting such a configuration, the heat uniformity can be improved over the entire heating surface.

[0072] FIG. 8 is a schematic diagram for explaining another example of the direction of the pattern surface S of the heating resistors 125 included in a plurality of heaters 120. FIG. 9 is an enlarged plan sectional view of part IX shown in FIG. 8. FIG. 10 is an enlarged side sectional view of part X shown in FIG. 8.

[0073] As shown in FIG. 9, in at least one heater 120_11 among the plurality of heaters 120, in a plan perspective view (shown as a cross section in FIG. 9) of the heater 120_11 along the longitudinal direction of the heater body 121 (here, the Z-axis direction), the center position C1 of the heater body 121 and the center position C2 of the heating resistor 125 may be displaced. Note that the center position C2 of the heating resistor 125 may also be referred to as the center position of the folded-back portion 125b in the plan perspective view shown in FIG. 9. Further, the center position C1 of the heater body 121 may also be referred to as the position of the central axis of the heater 120.

[0074] Thus, the heating device 100 according to the embodiment may have not only the heaters 120 in which the center position C1 of the heater body 121 and the center position C2 of the heating resistor 125 coincide, but also the heaters 120 (here, the heater 120_11) in which the center position C1 of the heater body 121 and the center position C2 of the heating resistor 125 are displaced. In such a configuration, since the positions of the heating resistors 125 that become the highest heat generation zones can be dispersed for each heater 120, the heat uniformity within the plane of the heating surface can be improved.

[0075] Also, as shown in FIG. 10, at least one heater 120_12 among the plurality of heaters 120 and the heater 120_13 adjacent to this heater 120_12 may have different distances from the tip portion 120a of the heater body 121 to the folded-back portion 125b.

[0076] The heating resistor 125 has a maximum heat generation point at the folded-back portion 125b. Therefore, with such a configuration, the position of the maximum heat generation point in the thickness direction of the heating plate 110 can be dispersed for each heater 120. Accordingly, the heating device 100 having such a configuration can improve the heat uniformity within the plane of the heating surface.

[0077] FIG. 11 is a schematic diagram for explaining another example of the orientation of the pattern surface S of the heating resistors 125 included in the plurality of heaters 120.

[0078] As shown in FIG. 11, in a plan view seen from a direction perpendicular to the upper surface 110a of the heating plate 110 which is the heating surface, the pattern surface S of the heater 120 located at the outermost periphery of the upper surface 110a of the heating plate 110 among the plurality of heaters 120 may be orthogonal to the edges 110c to 110f of the upper surface 110a of the heating plate 110.

[0079] For example, in the example shown in FIG. 11, the heaters 120_21 to 120_24 located in the XI1 portion are located at the place closest to the edge 110c of the upper surface 110a of the heating plate 110 among the plurality of heaters 120. The pattern surfaces S21 to S24 of these heaters 120_21 to 120_24 are orthogonal to the edge 110c. Similarly, the pattern surfaces S of the plurality of heaters 120 located in the XI2 portion are orthogonal to the edge 110d, the pattern surfaces S of the plurality of heaters 120 located in the XI3 portion are orthogonal to the edge 110e, and the pattern surfaces S of the plurality of heaters 120 located in the XI4 portion are orthogonal to the edge 110f.

[0080] With such a configuration, heat is likely to dissipate toward the outer peripheral direction of the heating plate 110. Accordingly, the heating device 100 having such a configuration can make it difficult to cause a temperature drop at the edge portion of the heating plate 110, and can further improve the heat uniformity within the plane of the heating surface.

[0081] Also, in the example shown in FIG. 11, among the plurality of heaters 120, the heater 120_25 located in the XI5 portion is located at the place closest to the corner between the edge 110c and the edge 110d of the upper surface 110a of the heating plate 110. The pattern surface S25 of such a heater 120_25 extends toward the corner between the edge 110c and the edge 110d. Similarly, the pattern surface S of the heater 120 located in the XI6 portion extends toward the corner between the edge 110d and the edge 110e, the pattern surface S of the heater 120 located in the XI7 portion extends toward the corner between the edge 110e and the edge 110f, and the pattern surface S of the heater 120 located in the XI8 portion extends toward the corner between the edge 110f and the edge 110c.

[0082] With such a configuration, heat is more likely to dissipate in the outer peripheral direction of the heating plate 110, so that the heat uniformity within the heating surface can be further improved.

[0083] FIG. 12 is a schematic diagram for explaining another example of the orientation of the pattern surface S of the heating resistors 125 included in the plurality of heaters 120.

[0084] The heaters 120_31 to 120_34 located in the XII portion shown in FIG. 12 are located at the central portion of the upper surface 110a of the heating plate 110. Specifically, the heaters 120_31 to 120_34 are adjacent to the center point C3 so as to surround the center point C3 of the upper surface 110a of the heating plate 110 in a plan view seen from a direction perpendicular to the upper surface 110a of the heating plate 110 which is the heating surface. The pattern surfaces S31 to S34 of these heaters 120_31 to 120_34 may be rotationally symmetric with respect to the center point C3 of the upper surface 110a. In the example shown in FIG. 12, the pattern surfaces S31 to S34 extend radially about the center point C3.

[0085] When such a configuration is adopted, symmetry can be imparted to the temperature distribution at the central portion of the upper surface 110a of the heating plate 110. Therefore, for example, when heating an object to be heated while applying pressure near the center of the heating plate 110 such as in pressing, the heat uniformity of the object to be heated is likely to be maintained.

[0086] FIG. 13 is a cross-sectional view showing another example of the heater 120 according to the embodiment. FIG. 14 is a schematic diagram for explaining another example of the orientation of the pattern surface S of the heating resistors 125 included in the plurality of heaters 120.

[0087] As shown in FIG. 13, the heater 120 may have two or more heating resistors 125 inside the heater body 121 with the orientations of the pattern surfaces S parallel to each other. The two or more heating resistors 125 are connected in parallel to the cathode-side lead electrode 124 and the anode-side lead electrode 123. FIG. 13 shows an example in the case where the heater 120 has two heating resistors 125, but the number of heating resistors 125 included in the heater 120 may be three or more.

[0088] As shown in FIG. 14, the plurality of heaters 120 included in the heating device 100 may incorporate two or more heating resistors 125 as shown in FIG. 13. With such a configuration, compared with the case where the heater 120 incorporates one heating resistor 125, the highest heat generation zones (the turning-back portions 125b) in the heater 120 are dispersed, so that the anisotropy of temperature due to the pattern shape of the heating resistor 125 can be made less likely to occur. Therefore, the heating device 100 having such a configuration can further improve the heat uniformity within the plane of the heating surface.

[0089] FIG. 15 is a cross-sectional view showing another example of the heater 120 according to the embodiment. FIG. 16 is a schematic diagram for explaining another example of the orientation of the pattern surface S of the heating resistors 125 included in the plurality of heaters 120.

[0090] As shown in FIG. 15, the heater body 121 of the heater 120 may have a square bar shape. As shown in FIG. 16, in the heating device 100 having such a heater 120, in all the heaters 120, the pattern surface S of the heater 120 and the pattern surface S of the heater 120 adjacent to the heater 120 may be orthogonal to each other. For example, in the example shown in FIG. 16, the heater 120 with the pattern surface S extending in the Y-axis direction and the heater 120 with the pattern surface S extending in the X-axis direction are alternately arranged along the X-axis direction and alternately arranged along the Y-axis direction.

[0091] In such a configuration, the temperature anisotropy caused by the pattern shape of the heating resistor 125 can be effectively canceled out over the entire upper surface 110a of the heating plate 110. Therefore, the heating device 100 having such a configuration can further improve the heat uniformity within the plane of the heating surface.

[0092] As described above, the heating device (for example, the heating device 100) according to the embodiment includes a heating plate (for example, the heating plate 110) and a plurality of heaters (for example, the heaters 120). The heating plate has a heating surface (for example, the upper surface 110a of the heating plate 110), and a plurality of recesses (for example, the recesses 113) are formed in the back surface (for example, the lower surface 110b of the heating plate 110) on the side opposite to the heating surface. The plurality of heaters are respectively inserted into the plurality of recesses. Inside each of the plurality of heaters, a wiring portion (for example, the heating resistor 125) having a pattern that spreads planar is located. Further, in at least one of the plurality of heaters, the direction of the pattern surface (for example, the pattern surface S) of the wiring portion is different from the direction of the pattern surface in the other heater adjacent to the heater.

[0093] Therefore, the heating device 100 according to the embodiment can improve the heat uniformity within the plane of the heating surface.

[0094] Further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspects of the present invention are not limited to the specific details and representative embodiments presented and described as above. Accordingly, various modifications are possible without departing from the spirit or scope of the general inventive concept defined by the appended claims and their equivalents.

Explanation of Signs

[0095] 100 Heating device 110 Heating plate 110a Upper surface 110b Lower surface 111 First plate member 111a Lower surface 111b Concave portion 112 Second plate member 112a Upper surface 112b Through-hole 113 Concave portion 114 Joining member 115 Heat insulating member 115a Through-hole 120 Heater 120a Tip portion 120b Base end portion 121 Heater body 122 Fixing member 122a First member 122b Second member 123 Anode side lead electrode 124 Cathode side lead electrode 125 Heating resistor 125a Extending portion 125b Folded-back portion 130 Fixing plate 131 Connecting member 140 Spacer member 170 Spacer member S pattern surface

Claims

1. A heating plate, and a plurality of heaters, wherein the heating plate has a heating surface and a plurality of recesses on a surface opposite to the heating surface, the plurality of heaters are respectively located in the plurality of recesses, a wiring portion having a pattern extending planar is located inside each of the plurality of heaters, at least one of the plurality of heaters has a different orientation of the pattern surface from that of the pattern surface in another heater adjacent to the heater, a heating device.

2. At least one of the plurality of heaters has a different orientation of the pattern surface from that of any of the pattern surfaces in two or more other heaters adjacent to the heater so as to surround the heater, the heating device according to claim 1.

3. In all of the plurality of heaters, the orientation of the pattern surface between adjacent heaters is different, the heating device according to claim 1.

4. At least one of the plurality of heaters has a pattern surface whose orientation is orthogonal to the orientation of the pattern surface in the other heater adjacent to the heater, the heating device according to claim 1.

5. Inside each of the plurality of heaters, two or more wiring portions having the same orientation of the pattern surface are located, the heating device according to claim 1.

6. the heater has a rod-shaped main body portion, the wiring portion is located inside the main body portion, the pattern surface faces a direction orthogonal to the longitudinal direction of the main body portion, At least one of the plurality of heaters has a displacement between the center position of the main body portion and the center position of the wiring portion in a planar perspective view looking along the longitudinal direction of the main body portion, the heating device according to claim 1.

7. The heater has a rod-shaped main body portion, and is inserted into the concave portion from the tip side of the main body portion. The wiring portion is located inside the main body portion, and has two extending portions extending along the longitudinal direction of the main body portion, and a folding-back portion connecting the two extending portions on the tip side of the main body portion. The heating device according to claim 1, wherein, among the plurality of heaters, at least one heater has a distance from the tip of the main body portion to the folding-back portion different from the distance in the other heaters.

8. In a plan view seen from a direction perpendicular to the heating surface, the pattern surface of the heater located at the outermost periphery of the heating surface among the plurality of heaters is orthogonal to the edge of the heating surface. The heating device according to claim 1.

9. In a plan view seen from a direction perpendicular to the heating surface, the pattern surfaces of two or more heaters adjacent to the center point so as to surround the center point of the heating surface are rotationally symmetric with respect to the center point. The heating device according to any one of claims 1 to 8.

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