Ceramic heater

Abstract

To provide a ceramic heater.SOLUTION: The ceramic heater includes: a plate having a heat-generation body and a first passage; a shaft having a hollow; and a thermocouple inserted into the first passage. The heat-generation body comprises multiple concentric arc parts, and multiple connection parts which connect the arc parts. A spaced area formed by the multiple connection parts spaced from and facing each other extends in the radial direction of the plate. The first passage is formed to be adjacent to the spaced area.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a ceramic heater, and more specifically, to a ceramic heater with an improved insertion structure for a temperature sensor.

Background Art

[0002] Generally, in order to manufacture a flat panel display panel or a semiconductor element, a series of layers including a dielectric layer and a metal layer are sequentially laminated and patterned on a substrate such as a glass substrate, a flexible substrate, or a semiconductor substrate. At this time, a series of layers such as the dielectric layer and the metal layer are deposited on the substrate by processes such as Chemical Vapor Deposition (CVD) or Physical Vapor Deposition (PVD).

[0003] In order to form these layers uniformly, it is necessary to heat the substrate to a uniform temperature, and a substrate heating device may be used to heat and support the substrate. The substrate heating device may be used for heating the substrate in an etching process of a dielectric layer or a metal layer formed on the substrate, a firing process of a photo resistor, etc.

[0004] A ceramic heater used as such a substrate heating device includes a heating element and a thermocouple for measuring the temperature of the heating element. The thermocouple is inserted into a thermocouple passage formed inside the ceramic heater, but heat generated by the heating element may be released through the thermocouple passage. When such heat loss occurs, it leads to a problem of a decrease in the temperature uniformity of the substrate disposed on the ceramic heater.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved is to prevent heat loss due to a passage into which a temperature sensor such as a thermocouple is inserted.

[0006] Another problem to be solved is to prevent cracks from occurring in the plate of the ceramic heater due to the expansion and contraction of the heating element.

[0007] Another problem to be solved is to measure the temperature of the heating element more accurately.

[0008] Another problem to be solved is to minimize the spatial volume of the thermocouple passage for installing a temperature sensor such as a thermocouple, facilitate the insertion of the thermocouple, and increase the insertion success rate.

Means for Solving the Problem

[0009] The ceramic heater according to an embodiment of the present invention includes a plate having a heating element and a first passage; a shaft having a hollow; and a thermocouple inserted into the first passage. The heating element includes a plurality of concentric arc portions and a plurality of connecting portions connecting the arc portions. A separation region formed by the plurality of connecting portions facing each other and separated from each other extends in the radial direction of the plate, and the first passage is formed adjacent to the separation region.

[0010] The plurality of connecting portions are aligned parallel to each other and form the separation region extending in the radial direction of the plate.

[0011] The plate includes a first heating portion and a second heating portion connected to the first heating portion and line-symmetrical to the first heating portion. The separation region is formed between the first heating portion and the second heating portion.

[0012] The first passage does not overlap the heating element in the thickness direction of the plate.

[0013] There may be a plurality of the separation regions and the first passages, respectively.

[0014] The plurality of first passages may include at least two first passages having different lengths from each other.

[0015] A ceramic heater according to another embodiment of the present invention includes a heating element and a plate having a first passage; a shaft having a hollow; and a thermocouple inserted into the first passage, wherein the first passage includes a first A passage portion parallel to a first surface of the plate and a second B passage portion inclined with respect to the first surface.

[0016] The plate includes a first plate portion and a second plate portion, the first A passage portion is located in the first plate portion, and the second B passage portion is located in the second plate portion.

[0017] The second B passage portion is inclined toward the heating element.

[0018] The second B passage portion is located at an end in the circumferential direction of the first passage.

[0019] The outlet area of the first A passage portion is smaller than the inlet area of the second B passage portion.

[0020] The temperature measuring portion of the thermocouple is located in the second B passage portion.

[0021] A ceramic heater according to still another embodiment of the present invention includes a heating element and a plate having a first passage; a shaft having a hollow; and a thermocouple inserted into the first passage, wherein the first passage includes a first A passage portion parallel to an upper end surface of the plate and a second C passage portion that gradually narrows from an upper end portion of the shaft to the first A passage portion between the first A passage portion and the upper end portion of the shaft.

[0022] The ceramic heater further includes a thermocouple guide disposed in the hollow of the shaft and having an upper end portion communicating with the second C passage portion, and the thermocouple is located inside the thermocouple guide, the second C passage portion, and the first A passage portion.

[0023] An end portion of the thermocouple guide may be inserted and fixed into a groove of the plate communicating with the second C passage portion.

[0024] The flat portion at the end of the thermocouple guide may be inserted and fixed into the groove of the plate connected to the C passage portion.

[0025] The embedded protrusion at the end of the thermocouple guide may be inserted and fixed into the C passage portion and the groove of the plate.

[0026] The protrusion at the end of the thermocouple guide may be inserted and fixed into the groove of the plate connected to the C passage portion.

[0027] The groove portion at the end of the thermocouple guide may be inserted and fixed into the groove of the plate connected to the C passage portion.

[0028] The threaded portion at the end of the thermocouple guide may be tightened and fixed to the threaded portion of the groove of the plate connected to the C passage portion.

Advantages of the Invention

[0029] According to the embodiment of the present invention, by arranging the passage into which the temperature sensor is inserted in an area where the heating elements are not concentrated, heat loss and cracks in the ceramic plate can be prevented.

[0030] Also, by arranging the temperature measuring portion of the temperature sensor close to the heating element, the temperature of the heating element can be measured more accurately.

[0031] Also, by mounting a thermocouple guide fixed in the shaft and using a passage having the curvature of the plate that minimizes the spatial volume of the thermocouple passage, the spatial volume of the thermocouple passage for installing a temperature sensor such as a thermocouple can be minimized, making it easy to insert the thermocouple and greatly improving the insertion success rate.

Brief Description of the Drawings

[0032]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

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Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Best Mode for Carrying Out the Invention

[0033] Hereinafter, with reference to the accompanying drawings, the embodiments disclosed in this specification will be described in detail. However, regardless of the reference numerals in the drawings, the same or similar components are given the same reference numerals, and redundant descriptions thereof are omitted. Hereinafter, in the description of the embodiments according to the present invention, when each layer (film), region, pattern or structure is described as being formed "on / above (on)" or "under / below (under)" the substrate, each layer (film), region, pad or pattern, "on / above (on)" and "under / below (under)" include both "directly" or "indirectly through other layers". Also, "on / above" or "under / below" each layer is described with reference to the drawings. In the drawings, the thickness and size of each layer are exaggerated, omitted or schematically shown for convenience and clarity of explanation. Note that the size of each component does not fully reflect the actual size.

[0034] In this description, expressions such as "including", "comprising" or "configured to" are for representing a certain characteristic, number, step, operation, element, part thereof or combination, and shall not be construed as excluding the existence or possibility of one or more other characteristics, numbers, steps, operations, elements, parts thereof or combinations other than those described.

[0035] Also, terms such as first and second may be used to describe various components, but these components are not limited by such terms as the first, second, etc., and these terms are only used for the purpose of distinguishing one component from another.

[0036] In addition, when explaining the embodiments disclosed in this specification, if it is determined that a specific description of related known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed description thereof will be omitted.

[0037] The accompanying drawings are only for facilitating the easy understanding of the embodiments disclosed in this specification, and the technical idea disclosed in this specification is not limited by the accompanying drawings, and should be understood to include any modifications, equivalents, or alternatives included in the idea and technical scope of the present invention.

[0038] Hereinafter, various embodiments of the present invention will be described in detail with reference to the drawings.

[0039] FIG. 1 is a perspective view of a ceramic heater according to an embodiment of the present invention.

[0040] The ceramic heater 10 is a device that supports heat treatment objects for various purposes such as semiconductor wafers, glass substrates, and flexible substrates, and heats the heat treatment object to a predetermined temperature.

[0041] The ceramic heater 10 includes a plate 20 on which a heat treatment object such as a semiconductor wafer W is placed, and a shaft 50 coupled to the lower surface 20b of the plate. The plate 20 includes a placement surface (first surface) 20a which is a flat upper end surface on which the heat treatment object is placed, and a lower surface (second surface) 20b to which the shaft 50 is coupled.

[0042] The plate 20 is a disc-shaped plate 20 containing a ceramic material such as aluminum nitride or alumina. The shaft 50 may be formed of a ceramic material such as aluminum nitride or alumina, similar to the plate 20.

[0043] FIG. 2 is a cross-sectional view taken from above after horizontally cutting the plate according to an embodiment of the present invention along the heating element. FIG. 3 is a cross-sectional view taken from above after horizontally cutting the plate according to still another embodiment of the present invention along the heating element. FIG. 4 is a partially enlarged view showing the P portion of FIG. 2.

[0044] Referring to FIGS. 2 to 4, the plate 20 is formed of a ceramic material and may be any one of Al2O3, Y2O3, Al2O3 / Y2O3, ZrO2, AlC, TiN, AlN, TiC, MgO, CaO, CeO2, TiO2, BxCy, BN, SiO2, SiC, YAG, mullite, AlF3, etc., or two or more of these may be used in combination.

[0045] The plate 20 may include a heating element 23. The heating element 23 functions to heat an object to be heat-treated located on the mounting surface 20a of the plate to a constant temperature so that the deposition process and the etching process can be smoothly performed in a semiconductor manufacturing process or the like.

[0046] The heating element 23 may be embedded in the plate 20 corresponding to the position of the object to be heat-treated. In addition to being able to uniformly control the heating temperature according to the position in order to uniformly heat the object to be heat-treated as a whole by heat generation, the heating element 23 may be embedded in the plate 20 parallel to the mounting surface 20a of the plate so that the heat transfer distance to the object to be heat-treated is kept constant at almost all positions.

[0047] The heating element 23 may be formed in a shape corresponding to the shape of the object to be heat-treated. Further, the heating element 23 may be formed in the form of a plate-shaped coil or a flat plate by a heating wire (or resistance wire). The heating element 23 may be formed of tungsten (W), molybdenum (Mo), molybdenum carbide (Mo2C, MoC, Mo3C2), silver (Ag), gold (Au), platinum (Pt), niobium (Nb), titanium (Ti), or an alloy thereof. The heating element 23 may be electrically connected to the terminals 21 and 22 by the conductive connection portion 28.

[0048] A pair of first terminals 21 and a pair of second terminals 22 may be formed at the center of the plate 20. The first terminal 21 electrically connects the internal zone heating element 24 formed in the internal region of the plate 20 and the power supply rod inside the shaft 50, and the second terminal 22 electrically connects the external zone heating element 25 formed in the external region of the plate 20 and the power supply rod inside the shaft 50.

[0049] In the present invention, the heating element 23 may be composed of two or more heating elements in order to heat a plurality of partitioned zones. Exemplarily, FIG. 2 shows a heating element 23 composed of an internal zone heating element 24 and an external zone heating element 25 for partitioning a plate into an internal zone and an external zone and heating each zone. Hereinafter, a heater partitioned into an internal zone and an external zone will be described, but the present invention is not limited thereto. For example, it goes without saying that the present invention can also be applied to a multi-zone heater in which a plate of a ceramic heater is partitioned into a fan shape at a predetermined angle and a heating element corresponding to each partitioned region is provided.

[0050] The internal zone heating element 24 starts from the first terminal 21a, is continuously wired in the internal region of the plate 20 while forming a certain pattern like concentric circles, and is then connected to the first terminal 21b. In this process, the internal zone heating element 24 can form a plurality of concentric circle pattern shapes while bending at a plurality of connection portions 23'.

[0051] The plurality of concentric circle patterns of the internal zone heating element 24 may include a plurality of concentric arc portions 24a-1, 24a-2, 24b-1, 24b-2 that extend along the circumferential direction of the plate 20. Further, it may include a plurality of connecting portions 23' that connect adjacent arc portions 24a-1, 24a-2, 24b-1, 24b-2 among the plurality of concentric arc portions 24a-1, 24a-2, 24b-1, 24b-2. Adjacent arc portions 24a-1, 24a-2, 24b-1, 24b-2 may be connected by a connecting portion 23' that extends in the diametrical direction.

[0052] The plurality of concentric arc portions 24a-1, 24a-2, 24b-1, 24b-2 may have different diameters from each other. Also, the plurality of connecting portions 23' may be aligned parallel to each other, and a separation region 26 that extends in the radial direction of the plate 20 can be formed in the plate 20 between them.

[0053] The internal zone heating element 24 may include a first internal heating portion 24a and a second internal heating portion 24b. The first internal heating portion 24a and the second internal heating portion 24b may form a line-symmetric structure about the diametrical direction of the plate 20 and may be connected to each other.

[0054] The arc portion 24a-1 of the first internal heating portion 24a and the arc portion 24b-1 of the second internal heating portion 24b are arc portions of the same diameter. The arc portion 24a-2 of the first internal heating portion 24a and the arc portion 24b-2 of the second internal heating portion 24b are also arc portions of the same diameter, and are arc portions with a larger diameter than the arc portion 24a-1 and the arc portion 24b-1. The arc portion 24a-1 is connected to the arc portion 24a-2 by the connecting portion 23'. The arc portion 24b-1 is connected to the arc portion 24b-2 by the connecting portion 23'.

[0055] The connecting portion 23' of the first internal heating portion 24a and the connecting portion 23' of the second internal heating portion 24b may be arranged facing each other with a certain distance E therebetween. A separation region 26 in which the internal zone heating element 24 is not wired may be formed in the plate 20 within the region formed by a virtual line I formed by the separated connecting portions 23'. The separation region 26 may extend in the radial direction of the plate 20.

[0056] The separation region 26 may be formed between the first internal heating part 24a and the second internal heating part 24b, and preferably may be formed within a region where a plurality of connecting parts 23' are aligned parallel to each other and extended in the radial direction of the plate 20. The separation region 26 may be formed in the circumferential direction from the central part of the plate 20.

[0057] The external zone heating element 25 starts from the second terminal 22a, is continuously wired to the external region of the plate 20 while forming a concentric pattern like a concentric circle, and then is connected to the second terminal 22b. In this process, the external zone heating element 25 can also form a concentric pattern while bending at a certain position in a form surrounding the internal zone heating element 24 (see FIG. 2), and can also form a plurality of concentric patterns while bending with a plurality of connecting parts 23' (see FIG. 3).

[0058] The plurality of concentric patterns of the external zone heating element 25 may include a plurality of concentric arc portions 25a-1, 25a-2, 25b-1, 25b-2 extending along the circumferential direction of the plate 20. Further, it may include a plurality of connecting parts 23' connecting adjacent arc portions 25a-1, 25a-2, 25b-1, 25b-2 among the plurality of concentric arc portions 25a-1, 25a-2, 25b-1, 25b-2. The adjacent arc portions 25a-1, 25a-2, 25b-1, 25b-2 may be connected by a connecting part 23' extending in the diameter direction.

[0059] The plurality of concentric arc portions 25a-1, 25a-2, 25b-1, 25b-2 may have different diameters. Also, the plurality of connecting parts 23' are aligned parallel to each other, and a separation region 26 extending in the radial direction of the plate 20 can be formed in the plate 20 between them.

[0060] The external zone heating element 25 may include a first external heating part 25a and a second external heating part 25b. The first external heating part 25a and the second external heating part 25b form a line-symmetric structure centered on the diameter direction of the plate 20 and may be connected to each other.

[0061] The arc portion 25a-1 of the first external heating portion 25a and the arc portion 25b-1 of the second external heating portion 25b are arc portions of the same diameter. The external zone heating element 25 may further include an arc portion 25a-2 of the first external heating portion 25a and an arc portion 25b-2 of the second external heating portion 25b. The arc portion 25a-2 and the arc portion 25b-2 are arc portions of the same diameter and are arc portions with a larger diameter than the arc portion 25a-1 and the arc portion 25b-1. The arc portion 25a-1 is connected to the arc portion 25a-2 by the connecting portion 23'. The arc portion 25b-1 is connected to the arc portion 25b-2 by the connecting portion 23'.

[0062] The connecting portion 23' of the first external heating portion 25a and the connecting portion 23' of the second external heating portion 25b may be arranged facing each other with a certain distance E therebetween. A separation region 26 in which the external zone heating element 25 is not wired may be formed in the plate 20 within the region formed by the virtual line I formed by the separated connecting portions 23'. The separation region 26 may extend in the radial direction of the plate 20.

[0063] The separation region 26 may be formed between the first external heating portion 25a and the second external heating portion 25b, and preferably, may be formed within the region formed by a plurality of connecting portions 23' being aligned parallel to each other and extending in the radial direction of the plate 20. Also, the separation region 26 may be formed between the conductive connecting portion 28 connected to the second terminal 22a and the conductive connecting portion 28 connected to the second terminal 22b. The separation region 26 may be formed by extending from the separation region 26 formed in the inner region in the circumferential direction from the central portion of the plate 20.

[0064] The internal zone heating element 24 and the external zone heating element 25 may be electrically separated and driven independently of each other.

[0065] A first passage 27 into which a temperature sensor 60 such as a thermocouple is inserted may be formed in the plate 20. The first passage 27 may be formed along the separation region 26 so as to be adjacent to the separation region 26. Also, the first passage 27 may be formed parallel to the mounting surface 20a of the plate.

[0066] As shown in FIGS. 2 to 4, when viewed in the thickness direction of the plate 20 from above the plate 20, the first passage 27 may be formed adjacent to the separation region 26 so as not to overlap with the heating element 23. Further, the first passage 27 may be formed adjacent to the separation region 26 formed between the conductive connection portion 28 connected to the second terminal 22a and the conductive connection portion 28 connected to the second terminal 22b.

[0067] As shown in FIGS. 2 and 3, a plurality of heating elements, for example, two heating elements 24 and 25, may be arranged independently of each other on the plate 20. As shown in FIG. 5, one single heating element 23 may be arranged in all regions of the plate 20.

[0068] Further, the plate 20 may include a plurality of separation regions 26 and a plurality of first passages 27, respectively. The separation regions 26 and the first passages 27 may be formed at a plurality of angular positions in the circumferential direction. At this time, all of the plurality of first passages 27 may have the same longitudinal length, but may be formed to have different longitudinal lengths depending on the design.

[0069] FIG. 6 is a cross-sectional view taken along the line C-C of FIG. 2.

[0070] Referring to FIG. 6, since the first passage 27 is formed along the separation region 26 adjacent to the separation region 26, as shown in FIG. 6, the heating element 23 may not be arranged above the first passage 27. By forming the first passage 27 in a region where the heating elements 23 are not concentrated, it is possible to prevent the heat generated by the heating elements 23 from being lost through the first passage 27 and improve the temperature uniformity of the heater. Further, it is possible to prevent cracks from occurring in the vulnerable portions of the plate 20 due to the expansion and contraction of the heating elements 23.

[0071] On the other hand, FIGS. 7 and 8 are diagrams showing that heat loss and microcracks occur when the first passage is formed in a region where the heating elements are concentrated.

[0072] As shown in FIG. 7, when the first passage 27 is formed adjacent to the heating element 23, the heat generated by the heating element 23 may be lost through the first passage 27.

[0073] Further, as shown in FIG. 8, when the first passage 27 is formed adjacent to the heating element 23, fine cracks may occur in the thin portion of the plate 20 due to the expansion and contraction of the heating element 23.

[0074] FIG. 9 is a C-C cross-sectional view of a plate according to still another embodiment of the present invention.

[0075] A temperature sensor 60 such as a thermocouple is inserted into the first passage 27 of the plate 20. The first passage 27 may be composed of a first A passage portion 27a formed parallel to the mounting surface 20a of the plate and a first B passage portion 27b inclined with respect to the mounting surface 20a.

[0076] The first B passage portion 27b is disposed at the circumferential end of the first passage 27, and the temperature measuring portion of the temperature sensor 60 may be located there. By forming the first B passage portion 27b to be inclined toward the heating element 23, the distance between the temperature measuring portion of the temperature sensor 60 and the heating element 23 can be minimized. Further, by positioning the circumferential end of the first B passage portion 27b at the same height as the heating element 23, that is, on the same plane, in the thickness direction of the plate 20, the temperature of the region between the heating element connecting portions 23' can be measured more accurately.

[0077] FIG. 10 is a diagram for explaining the process of manufacturing the plate 20 of FIG. 9, FIG. 11 is a partially enlarged view showing the Z portion of FIG. 9, and FIG. 12 is a cross-sectional view taken along the E-E direction of FIG. 11.

[0078] The plate 20 may be composed of an upper plate P2 and a lower plate P1. The first B passage portion 27b may be formed in the upper plate P2, and the first A passage portion 27a may be formed in the lower plate P1.

[0079] The first passage portion 27a and the second passage portion 27b may be in the form of grooves or holes extending longitudinally in the circumferential direction of the plate 20 so that a temperature sensor 60 such as a thermocouple can be inserted. The first passage portion 27a and the second passage portion 27b may have various cross-sectional shapes such as circular or square.

[0080] The plate 20 may be produced by joining a lower plate P1 and an upper plate P2 in which the first passage portion 27a and the second passage portion 27b are formed. At this time, if the first passage portion 27a and the second passage portion 27b are not accurately aligned, the space through which the temperature sensor 60 can pass is reduced, making it difficult or impossible to insert the temperature sensor 60 into the second passage portion 27b.

[0081] As shown in FIG. 11, the second passage portion 27b can be processed into a shape such as a pyramid (e.g., a cone, triangular pyramid, or square pyramid), a frustum of a cone, or a frustum of a pyramid so that the upper plate P2 and the lower plate P1 can be easily aligned when joined. In this way, by forming the cross-sectional area of the end of the second passage portion 27b to be small, the temperature measuring portion of the thermocouple inserted into the second passage portion 27b does not shake, and the temperature measurement accuracy can be improved.

[0082] When the upper plate P2 and the lower plate P1 are joined, an outlet of the first passage portion 27a, which is a hole through which the temperature sensor 60 can pass, may be formed at one end of the first passage portion 27a formed in the lower plate P1. Also, an inlet of the second passage portion 27b, which is a hole through which the temperature sensor 60 can pass, may be located at a position in contact with the outlet of the first passage portion 27a.

[0083] By the outlet of the first passage portion 27a and the inlet of the second passage portion 27b being in contact, the first passage portion 27a and the second passage portion 27b can integrally form the first passage 27. At this time, in order to prevent the space through which the temperature sensor 60 passes from being reduced even if the first passage portion 27a and the second passage portion 27b are not accurately aligned, the inlet area D2 of the second passage portion 27b can be formed larger than the outlet area D1 of the first passage portion 27a.

[0084] Further, by positioning the margin space of the inlet area D2 of the second passage portion 27b, i.e., the space corresponding to (D2 - D1), so as to extend in a direction away from the center of the plate 20, a temperature sensor 60 such as a thermocouple can be easily inserted into the second passage portion 27b. That is, the thermocouple inserted through the first passage portion 27a can be easily inserted along the inner wall of the second passage portion 27b without hitting the upper plate P2 at the inlet of the second passage portion 27b.

[0085] Further, the second passage portion 27b may be formed in a form in which the cross-sectional area decreases in a direction away from the center of the plate 20.

[0086] Thus, by forming the inlet area D2 of the second passage portion 27b to be larger than the outlet area D1 of the first passage portion 27a, when assembling the plate 22, it is possible to assemble while allowing an alignment error in the radial direction (left - right direction in FIG. 10) of the plate 22. Also, as shown in FIG. 12, by forming the width of the second passage portion 27b to be larger than the width of the first passage portion 27a, it is also possible to assemble the plate 22 while allowing an alignment error in the rotational direction (circumferential direction of the plate).

[0087] FIG. 13 is a partial cross - sectional view of the B - B cross - section of FIG. 1. Here, reference is made to the cross - sectional view PC and the plan view PU of the joint portion between the plate 20 and the shaft 50.

[0088] Referring to FIG. 13, the shaft 50 may be formed in a cylindrical shape with a wall having a predetermined thickness and having a space (hollow) 55 inside. A plurality of power supply rods (not shown) connected to the terminals of the plate 20 may be installed in the internal space of the shaft 50. A predetermined mount 90 may be provided on the lower side of the shaft 50, whereby a plurality of power supply rods (not shown) and the thermocouple guide 70 can be fixed on the lower side.

[0089] Hereinafter too, the configurations such as the plate 20 including the heating element 23 and the first passage 27, the shaft 50, and the thermocouple 60 may be applied as described above in the same manner as in FIGS. 1 to 13.

[0090] As described above, the plate 20 may be composed of the upper plate P2 and the lower plate P1 as described above. As shown in FIG. 10, a second B passage portion 27b (which may be omitted) may be formed in the upper plate P2, and a first A passage portion 27a may be formed in the lower plate P1.

[0091] In addition, as shown in FIG. 13, the first passage 27 may include a third C passage portion 27c that gradually narrows from the upper end of the shaft 50 to the first A passage portion 27a between the first A passage portion 27a and the upper end of the shaft 50. The third C passage portion 27c may be formed in the plate 20. When the lower plate P1 and the upper plate P2 are separated, the third C passage portion 27c may be formed in the lower plate P1, or may be formed to continue from the lower plate P1 to a part of the upper plate P2.

[0092] By providing the third C passage portion 27c that gradually narrows from the upper end of the shaft 50 to the first A passage portion 27a, the space volume of the thermocouple passage in the third C passage portion 27c can be minimized by the passage having the curvature of such a plate 20 as compared with the case where the third C passage portion 27c is formed of a hexahedral passage. Since the temperature measuring portion at the end of the temperature sensor 60 is pushed and inserted toward the first A passage portion 27a while being in contact with the curved surface of the third C passage portion 27c, the curved surface portion is formed of a round surface such as a disk shape, a spherical shape, or an oval shape that reaches from the upper end of the shaft 50 to the first A passage portion 27a so as to facilitate the insertion. That is, the space of the third C passage portion 27c may be a part of a shape having a curved surface such as a disk shape, a spherical shape, or an oval shape.

[0093] A temperature sensor 60 such as a thermocouple may be inserted into the first passage 27 of the plate 20 through a thermocouple guide 70 having a through hole provided in the hollow 55 of the shaft 50. The thermocouple guide 70 is disposed in the hollow 55 of the shaft 50, and its upper end is disposed so as to meet the Cth passage portion 27c. That is, the temperature sensor 60 such as a thermocouple may be positioned across the inside of the thermocouple guide 70, the Cth passage portion 27c, and the Ath passage portion 27a. As described above, the temperature measuring portion at the end of the temperature sensor 60 may be pushed and inserted to the end of the Ath passage portion 27a. Also, when the Bth passage portion 27b is provided, the temperature measuring portion at the end of the temperature sensor 60 may be pushed and inserted to the end of the Bth passage portion 27b.

[0094] The end of the thermocouple guide 70 may be inserted and fixed in a groove in the plate 20 or the lower plate P1 connected to the Cth passage portion 27c. As shown in Fig. 20, if the thermocouple guide 70 is not fixed, the success rate of insertion decreases due to shaking of the thermocouple guide 70 when the temperature sensor 60 is pushed and inserted into the inside of the thermocouple guide 70, the Cth passage portion 27c, and the Ath passage portion 27a.

[0095] In the past, there was a method (conventional method) of making a thermocouple guide curved (not shown) and bringing its end close to the Ath passage portion 27a, but in this case, in addition to the problem that it is difficult to bring the end of the thermocouple guide close to the Ath passage portion 27a, the thermocouple guide is not fixed, so in the process of inserting and pushing the thermocouple into it, the thermocouple also wobbles, etc., and the insertion success rate decreases. Furthermore, in order to insert the curved thermocouple guide of the conventional method into the shaft, a large amount of processing space must be secured in the plate 20 so that the end of the thermocouple guide can be brought close to the Ath passage portion 27a, and this processing space can cause a decrease in the temperature uniformity of the plate, and heat loss also occurs through the attached thermocouple guide, which can cause cracks in the plate and hinder the maintenance of temperature uniformity.

[0096] Therefore, in the present invention, a linear thermocouple guide 70 is fixed within the shaft 50 to facilitate the insertion of the thermocouple. Further, by providing a C passage portion 27c that gradually narrows from the upper end portion of the shaft 50 to the A passage portion 27a, the space volume of the thermocouple passage in the C passage portion 27c can be minimized compared to the case where the C passage portion 27c forms a hexahedral passage due to the passage having the curvature of the plate 20. The C passage portion 27c having such a curvature allows the temperature measuring portion at the end of the temperature sensor 60 to be pushed and inserted toward the A passage portion 27a while contacting along the curved surface, thus making it possible to significantly increase the insertion success rate.

[0097] To explain in more detail the advantages of the structure in which a linear thermocouple guide 70 is fixed within the shaft 50 of the present invention and the curved surface of the C passage portion 27c is utilized, it is as follows.

[0098] 1) Effect of reducing the volume of the thermocouple passage

[0099] - The improved structure of the present invention can not only improve the insertion effect of the thermocouple compared to the structure of the prior art, but also effectively reduce the volume of the thermocouple passage.

[0100] - Further, by reducing the volume of the thermocouple passage, the temperature uniformity and durability of the plate 20 can be improved.

[0101] 2) Effect of removing the thermocouple guide

[0102] - The improved structure of the present invention can minimize the insertion of the thermocouple guide 70.

[0103] - Also, by minimizing the heat loss due to the thermocouple guide 70, the temperature uniformity of the plate 20 can be improved, and the occurrence of cracks due to rapid heat loss can be prevented.

[0104] 3) Effect of improving the stability of thermocouple insertion

[0105] - The improved structure of the present invention is such that when the thermocouple is inserted, the thermocouple bends due to the curvature of the plate 20. At this time, the fixed thermocouple guide 70 serves to support the thermocouple so that it can bend along the curvature of the plate 20.

[0106] - Also, by improving the fixing force of the thermocouple guide 70, the insertion success rate of the thermocouple can be improved.

[0107] - Further, as the radius of curvature of the curved surface portion of the plate 20 becomes smaller, more force acts on the plate 20 during insertion. However, due to the improvement in the fixing force of the thermocouple guide 70, the radius of curvature of the plate 20 that can be inserted can provide the same effect even if it decreases compared to the case where the thermocouple guide 70 is not fixed.

[0108] - Also, when using the ceramic heater in the semiconductor process, conventionally, there was a problem that the thermocouple guide 70 was not fixed and the position of the thermocouple moved. However, in the present invention, the thermocouple guide 70 is fixed and the position of the thermocouple is fixed without moving during use, so the service durability is improved.

[0109] On the other hand, in the present invention, such a thermocouple guide 70 may have its end inserted and fixed into the groove of the plate 20 connected to the C - passage portion 27c, and the lower side may be fixed to a predetermined mount 90. The thermocouple guide 70 made of a ceramic material or the like as described above may be in the form of a straight pipe or tube as shown in FIG. 13, and its end may be inserted and fixed into the corresponding groove of the plate 20. However, as will be described later, depending on various embodiments, the thermocouple guide 70 may be inserted and fixed into the groove of the plate 20 or the lower plate P1 in various ways.

[0110] FIG. 14 is an enlarged view showing another embodiment of the connection portion between the plate 20 and the shaft 50 in the B - B cross - section of FIG. 1. Here, reference is made to the cross - sectional view PC and the plan view PU.

[0111] Referring to Fig. 14, the flat portion 71 at the end of the thermocouple guide 70 may be inserted and fixed into the groove 31 of the plate 20 that is connected to the C-channel portion 27c. When the flat portion 71 is inserted into the groove 31 of the plate 20 to fix the thermocouple guide 70, the flat portion 71 having a predetermined shape such as a square plate shape corresponding to the shape of the groove 31 can increase the insertion area and improve the fixing force. Here, the square plate-shaped flat portion 71 has a portion that extends further on the other side than a portion that extends larger than the diameter of the body of the thermocouple guide 70 on one side at the end of the thermocouple guide 70. The flat portion 71 may be an integral type formed by processing the material end of the thermocouple guide 70 into the said shape, or may be separately manufactured and joined to the end of the thermocouple guide 70 by welding or ceramic bonding or the like.

[0112] Fig. 15 is an enlarged view showing still another embodiment of the connection portion between the plate 20 and the shaft 50 in the B-B cross section of Fig. 1. Here, reference is made to the cross-sectional view PC and the plan view PU.

[0113] Referring to Fig. 15, the embedded protrusion 71-1 at the end of the thermocouple guide 70 may be inserted and fixed into the groove 31 of the plate 20 and the C-channel portion 27c. The embedded protrusion 71-1 in the form of filling the insertion groove 31 of the plate 20 and the C-channel portion 27c can increase the insertion area and, by being inserted inside the C-channel portion 27c, improve the fixing force and the insertion success rate. The embedded protrusion 71-1 may be an integral type formed by processing the material end of the thermocouple guide 70 into the said shape, or may be separately manufactured and joined to the end of the thermocouple guide 70 by welding or ceramic bonding or the like.

[0114] Fig. 16 is an enlarged view showing still another embodiment of the connection portion between the plate 20 and the shaft 50 in the B-B cross section of Fig. 1. Here, reference is made to the cross-sectional view PC and the plan view PU.

[0115] Referring to FIG. 16, the flat portion 72 at the end of the thermocouple guide 70 may be inserted and fixed into the groove 32 of the plate 20 connected to the C-channel portion 27c. The flat portion 72 is inserted into the groove 32 of the plate 20 to fix the thermocouple guide 70. The flat portion 72 having a predetermined shape such as a rectangular plate corresponding to the shape of the groove 32 can increase the insertion area and improve the fixing force. Here, the flat portion 71 having a rectangular plate shape is made into a square plate shape. The flat portion 72 may be an integral type formed by processing the material end of the thermocouple guide 70 into such a shape, or may be separately manufactured and joined to the end of the thermocouple guide 70 by welding or ceramic bonding or the like.

[0116] In addition to the embodiments of FIGS. 14 and 16, the flat portion can be implemented in various shapes such as a disk shape, various rectangular plate shapes, an elliptical plate shape, a star-shaped plate shape, etc. at the end of the thermocouple guide 70. Such flat portions 71, 72 of the thermocouple guide 70 can increase the area inserted into the plate 20 and improve the fixing force.

[0117] FIG. 17 is an enlarged view showing still another embodiment of the connection portion between the plate and the shaft in the B-B cross section of FIG. 1. Here, reference is made to the cross-sectional view PC and the plan view PU.

[0118] Referring to FIG. 17, the protruding portion 73 at the end of the thermocouple guide 70 may be inserted and fixed into the groove 33 of the plate 20 connected to the C-channel portion 27c. Here, the cross-sectional shapes of the protruding portion 73 and the corresponding groove 33 of the plate 20 can be implemented in various shapes such as a circular shape, various quadrilateral shapes, an elliptical shape, a star shape, etc. Similarly, such a protruding portion 73 of the thermocouple guide 70 can improve the fixing force so as to reduce shaking.

[0119] FIG. 18 is an enlarged view showing still another embodiment of the connection portion between the plate and the shaft in the B-B cross section of FIG. 1. Here, reference is made to the cross-sectional view PC and the plan view PU.

[0120] Referring to FIG. 18, the groove portion 74 at the end of the thermocouple guide 70 may be inserted and fixed into the groove (portion) 34 of the plate 20 connected to the C passage portion 27c. Here, the cross-sectional shapes of the groove portion 74 and the corresponding groove 34 of the plate 20 can be implemented in various shapes such as circular, various quadrangular, elliptical, star-shaped, and the like. Similarly, for the groove portion 74 of such a thermocouple guide 70, the fixing force can be improved so as to reduce shaking.

[0121] FIG. 19 is an enlarged view showing still another embodiment with respect to the connecting portion between the plate and the shaft in the B-B cross section of FIG. 1. Here, it is assumed that the cross-sectional view PC and the plan view PU are referred to.

[0122] Referring to FIG. 19, the threaded portion 75 (for example, male thread) at the end of the thermocouple guide 70 may be tightened (threaded) and fixed to the threaded portion 39 (for example, female thread) of the groove 35 of the plate 20 connected to the C passage portion 27c. Similarly, for the threaded portion 75 of such a thermocouple guide 70, the fixing force can be improved so as to reduce shaking.

[0123] As described above, in the present invention, specific matters such as specific components, limited embodiments, and drawings have been described, but this is only provided to assist in a more general understanding of the present invention. The present invention is not limited to the above embodiments, and various modifications and variations are possible for those having ordinary knowledge in the field to which the present invention pertains without departing from the essential characteristics of the present invention. Therefore, the idea of the present invention should not be defined only by the described embodiments, and not only the scope of the following claims, but also any technical idea with a modification equivalent or equivalent to this scope of claims should be interpreted as being included in the scope of rights of the present invention. Also, each of the above embodiments can be operably combined with each other as necessary.

Explanation of Reference Numerals

[0124] 10 Ceramic heater 20 Plate 23 Heating element 26 Isolation region 27 First passageway 27a Passageway section A 27b Passageway section B 27c Passageway section C 50 Shaft

Claims

1. a plate having a heating element and a first passage; A shaft having a hollow space; a thermocouple inserted into the first passage; The first passage does not overlap the heating element in a thickness direction of the plate, The first passage includes an A passage portion parallel to an upper end surface of the plate, and a C passage portion between the A passage portion and an upper end of the shaft, the C passage portion gradually narrowing from the upper end of the shaft to the A passage portion.

2. a plate having a heating element and a first passage; A shaft having a hollow space; a thermocouple inserted into the first passage; the first passage includes an A passage portion parallel to an upper end surface of the plate, and a C passage portion between the A passage portion and an upper end portion of the shaft, the C passage portion gradually narrowing from the upper end portion of the shaft to the A passage portion, a thermocouple guide disposed within the hollow of the shaft, the upper end of the thermocouple guide meeting the C passage portion; The thermocouple is located inside the thermocouple guide, in the C passage portion, and in the A passage portion.

3. 2. The ceramic heater of claim 1, further comprising a thermocouple guide disposed within said hollow of said shaft, said upper end meeting said C passage portion.

4. 2. The ceramic heater according to claim 1, wherein the heating element comprises a plurality of concentric arc portions and a plurality of connecting portions connecting the arc portions, a separation region formed by the plurality of connecting portions facing each other at a distance extends in a radial direction of the plate, and the first passage is formed adjacent to the separation region.

5. 4. The ceramic heater according to claim 2, wherein an end of said thermocouple guide is inserted into and fixed to a groove of said plate connected to said C passage portion.

6. 4. The ceramic heater according to claim 2, wherein a flat portion at an end of said thermocouple guide is inserted into and fixed to a groove in said plate connected to said C passage portion.

7. 4. The ceramic heater according to claim 2, wherein an embedded protrusion at an end of said thermocouple guide is inserted into said C passage portion and a groove in said plate and fixed thereto.

8. 4. The ceramic heater according to claim 2, wherein a protruding portion at an end of said thermocouple guide is inserted into and fixed to a groove in said plate connected to said C passage portion.

9. 4. The ceramic heater according to claim 2, wherein a groove portion at an end portion of said thermocouple guide is inserted into and fixed to a groove of said plate connected to said C passage portion.

10. 4. The ceramic heater according to claim 2, wherein a threaded portion at an end of said thermocouple guide is fastened and fixed to a threaded portion of a groove of said plate connected to said C passage portion.

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