Ceramic heater

Abstract

To provide a ceramic heater.SOLUTION: A ceramic heater 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, wherein the heating element includes a plurality of concentric arc portions and a plurality of connection portions connecting the arc portions, a separation region formed by the plurality of connection portions facing each other while being spaced apart from each other extends in a radial direction of the plate, and the first passage is formed adjacent to the separation region.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a ceramic heater, and more particularly to a ceramic heater having an improved temperature sensor insertion structure. [Background technology]

[0002] In general, in order to manufacture a flat display panel or a semiconductor device, a series of layers including a dielectric layer and a metal layer are sequentially stacked and patterned on a substrate such as a glass substrate, a flexible substrate, a semiconductor substrate, etc. In this case, the series of layers including the dielectric layer and the metal layer are deposited on the substrate by a process such as chemical vapor deposition (CVD) or physical vapor deposition (PVD).

[0003] To uniformly form these layers, the substrate needs to be heated to a uniform temperature, and a substrate heater may be used to heat and support the substrate. The substrate heater may be used to heat the substrate during an etching process for a dielectric layer or a metal layer formed on the substrate, a baking process for a photoresistor, or the like.

[0004] Ceramic heaters used as such substrate heating devices include 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, and heat generated by the heating element can be dissipated through the thermocouple passage. This heat loss can lead to a problem of reduced temperature uniformity of a substrate placed on the ceramic heater. Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved is to prevent heat loss through 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 ceramic heater plate 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 a thermocouple passage for installing a temperature sensor such as a thermocouple, thereby facilitating the insertion of the thermocouple and increasing the success rate of insertion. [Means for solving the problem]

[0009] A ceramic heater according to an embodiment of the present invention includes a plate having a heating element and a first passage; a hollow shaft; and a thermocouple inserted into the first passage, wherein the heating element has a plurality of concentric arc portions and a plurality of connecting portions connecting the arc portions, and a separation region formed by the connecting portions facing each other at a distance 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 one another to form the spaced apart regions 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 axisymmetrical to the first heating portion, and 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] The separation region and the first passage may each be plural.

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

[0015] A ceramic heater according to another 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 first passage including a passage portion A parallel to a first surface of the plate and a passage portion B inclined relative to the first surface.

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

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

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

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

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

[0021] A ceramic heater according to yet another 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 first passage including a passage A portion parallel to an upper end surface of the plate, and a passage C portion between the passage A portion and an upper end of the shaft, the passage C gradually narrowing from the upper end of the shaft to the passage A portion.

[0022] The shaft further includes a thermocouple guide disposed within the hollow and having an upper end that meets the C passage portion, the thermocouple being located within the thermocouple guide, the C passage portion, and the A passage portion.

[0023] An end of the thermocouple guide may be inserted into and fixed in a groove of the plate that is connected to the C passage portion.

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

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

[0026] A protruding portion at an end of the thermocouple guide may be inserted into and fixed to a groove in the plate that is connected to the C passage portion.

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

[0028] A threaded portion at an end of the thermocouple guide may be fastened to a threaded portion of a groove in the plate that is connected to the C passage portion and fixed thereto. [Effects of the Invention]

[0029] According to an embodiment of the present invention, the passage through which the temperature sensor is inserted is located in an area where the heating elements are not densely packed, thereby preventing heat loss and cracking of the ceramic plate.

[0030] Furthermore, by locating 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] In addition, by installing a thermocouple guide fixed inside the shaft and using a passage with a 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 easier to insert the thermocouple and significantly improving the insertion success rate. [Brief explanation of the drawings]

[0032] [Figure 1] 1 is a perspective view of a ceramic heater according to an embodiment of the present invention. [Figure 2]1 is a cross-sectional view of a plate according to an embodiment of the present invention, cut horizontally along a heating element and viewed from above. [Figure 3] FIG. 10 is a cross-sectional view of a plate according to another embodiment of the present invention, cut horizontally along the heating element and viewed from above. [Figure 4] FIG. 3 is a partially enlarged view showing a portion P in FIG. 2. [Figure 5] FIG. 10 is a cross-sectional view of a plate according to yet another embodiment of the present invention, cut horizontally along the heating element and viewed from above. [Figure 6] 3 is a cross-sectional view taken along CC in FIG. 2. [Figure 7] FIG. 10 is a diagram of a comparative example showing heat loss that occurs when a first passage is formed in an area where heat generating elements are densely located. [Figure 8] FIG. 10 is a diagram of a comparative example showing microcracks that occur when first passages are formed in an area where heating elements are densely packed. [Figure 9] 10 is a cross-sectional view of a plate according to still another embodiment of the present invention. [Figure 10] 10A to 10C are diagrams illustrating the steps of manufacturing the plate of FIG. 9. [Figure 11] FIG. 10 is a partially enlarged view showing a portion Z in FIG. 9. [Figure 12] 12 is a cross-sectional view of FIG. 11 taken along E-E axis. [Figure 13] FIG. 2 is a part of a cross-sectional view taken along the line BB in FIG. [Figure 14] 1. FIG. 5 is an enlarged view of the BB cross section of FIG. 1 showing another embodiment of the joining portion between the plate and the shaft. [Figure 15] 1. FIG. 5 is an enlarged view of the BB cross section of FIG. 1 showing still another embodiment of the joining portion between the plate and the shaft. [Figure 16] 1. FIG. 5 is an enlarged view of the BB cross section of FIG. 1 showing still another embodiment of the joining portion between the plate and the shaft. [Figure 17] 1. FIG. 5 is an enlarged view of the BB cross section of FIG. 1 showing still another embodiment of the joining portion between the plate and the shaft. [Figure 18]1. FIG. 5 is an enlarged view of the BB cross section of FIG. 1 showing still another embodiment of the joining portion between the plate and the shaft. [Figure 19] 1. FIG. 5 is an enlarged view of the BB cross section of FIG. 1 showing still another embodiment of the joining portion between the plate and the shaft. [Figure 20] FIG. 10 is an enlarged view showing an example of a joint portion between a plate and a shaft when a thermocouple guide is not fixed. DETAILED DESCRIPTION OF THE INVENTION

[0033] Hereinafter, embodiments disclosed herein will be described in detail with reference to the accompanying drawings. Identical or similar elements will be designated by the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted. Hereinafter, in the description of embodiments of the present invention, when a layer (film), region, pattern, or structure is described as being formed "on" or "under" a substrate, a layer (film), region, pad, or pattern, "on" and "under" include both being formed "directly" and "indirectly via another layer." Furthermore, the "on" or "under" of each layer will be described with reference to the drawings. In the drawings, the thickness and size of each layer may be exaggerated, omitted, or simplified for convenience and clarity of description. The size of each element may not exactly reflect the actual size.

[0034] In this description, expressions such as "comprises," "has," or "comprises" are intended to express certain characteristics, numbers, steps, operations, elements, parts thereof, or combinations thereof, and should not be interpreted as excluding the presence or possibility of one or more other characteristics, numbers, steps, operations, elements, parts thereof, or combinations other than those stated.

[0035] Furthermore, terms such as "first" and "second" may be used to describe various components, but these components are not limited to the terms "first" and "second", and these terms are only used to distinguish one component from another.

[0036] Furthermore, when describing the embodiments disclosed in this specification, if it is determined that a specific description of related publicly known technology may obscure the gist of the embodiments disclosed in this specification, that detailed description will be omitted.

[0037] The accompanying drawings are merely intended to facilitate understanding of the embodiments disclosed in this specification, and should not be construed as limiting the technical ideas disclosed in this specification, but should be understood to include any modifications, equivalents, or alternatives included within the spirit and technical scope of the present invention.

[0038] Various embodiments of the present invention will now 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 various objects to be heat-treated, such as semiconductor wafers, glass substrates, flexible substrates, etc., and heats the objects to be heat-treated to a predetermined temperature.

[0041] The ceramic heater 10 comprises a plate 20 on which an object to be heat-treated, such as a semiconductor wafer W, is placed, and a shaft 50 coupled to the lower surface 20b of the plate. The plate 20 has a loading surface (first surface) 20a, which is a flat upper surface on which the object to be heat-treated 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 made of a ceramic material such as aluminum nitride or alumina. The shaft 50 may be made of a ceramic material such as aluminum nitride or alumina, similar to the plate 20.

[0043] FIG. 2 is a cross-sectional view of a plate according to an embodiment of the present invention, cut horizontally along the heating element and viewed from above; FIG. 3 is a cross-sectional view of a plate according to yet another embodiment of the present invention, cut horizontally along the heating element and viewed from above; and FIG. 4 is a partially enlarged view showing part P in FIG. 2.

[0044] 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 a combination of two or more of these may be used.

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

[0046] The heating element 23 may be embedded in the plate 20 at a position corresponding to the position of the object to be heat-treated. The heating element 23 may be embedded in the plate 20 parallel to the mounting surface 20a of the plate so that the heating temperature can be controlled uniformly depending on the position in order to heat the object to be heat-treated uniformly throughout the object by generating heat, and the distance of heat transfer 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. The heating element 23 may also be formed in the form of a plate coil or a flat plate using 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 a conductive connection 28.

[0048] A pair of first terminals 21 and a pair of second terminals 22 may be formed in the center of the plate 20. The first terminals 21 electrically connect an inner zone heating element 24 formed in the inner region of the plate 20 to a power supply rod inside the shaft 50, and the second terminals 22 electrically connect an outer zone heating element 25 formed in the outer region of the plate 20 to a 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 to heat multiple zones. For example, FIG. 2 shows a heating element 23 in which a plate is divided into an inner zone and an outer zone, and an inner zone heating element 24 and an outer zone heating element 25 are used to heat each zone. While the following describes a heater divided into an inner zone and an outer zone, the present invention is not limited thereto. For example, the present invention can also be applied to a multi-zone heater in which the plate of a ceramic heater is divided into sectors at a predetermined angle and heating elements are provided corresponding to each divided zone.

[0050] The inner zone heating element 24 is continuously wired in the inner region of the plate 20 starting from the first terminal 21a, forming a certain pattern such as a concentric circle, and then connected to the first terminal 21b. In this process, the inner zone heating element 24 can be bent at multiple connecting portions 23' to form multiple concentric circle patterns.

[0051] The multiple concentric circular patterns of the internal zone heating element 24 may include multiple concentric arc portions 24a-1, 24a-2, 24b-1, and 24b-2 extending along the circumferential direction of the plate 20. The multiple concentric arc portions 24a-1, 24a-2, 24b-1, and 24b-2 may also include multiple connecting portions 23' connecting adjacent arc portions 24a-1, 24a-2, 24b-1, and 24b-2 among the multiple concentric arc portions 24a-1, 24a-2, 24b-1, and 24b-2. Adjacent arc portions 24a-1, 24a-2, 24b-1, and 24b-2 may be connected by connecting portions 23' extending in the diameter direction.

[0052] The concentric arc portions 24a-1, 24a-2, 24b-1, and 24b-2 may have different diameters, and the connecting portions 23′ may be aligned parallel to one another to form spaced apart regions 26 extending in the radial direction of the plate 20 therebetween.

[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 be configured to be line-symmetrical about the diameter of the plate 20 and connected to each other.

[0054] The arc portion 24a-1 of the first internal heat generating portion 24a and the arc portion 24b-1 of the second internal heat generating portion 24b are arc portions of the same diameter. The arc portion 24a-2 of the first internal heat generating portion 24a and the arc portion 24b-2 of the second internal heat generating portion 24b are also arc portions of the same diameter, but are arc portions with a larger diameter than the arc portions 24a-1 and 24b-1. The arc portion 24a-1 is connected to the arc portion 24a-2 by a connecting portion 23'. The arc portion 24b-1 is connected to the arc portion 24b-2 by a 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 disposed facing each other at a predetermined distance E. A separation region 26 where the internal zone heating element 24 is not wired may be formed on the plate 20 within an area defined by an imaginary line I formed by separating the 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 heat generating portion 24a and the second internal heat generating portion 24b, and may preferably be formed in a region formed by aligning the plurality of connecting portions 23′ in parallel with one another and extending in the radial direction of the plate 20. The separation region 26 may be formed in the circumferential direction from the center of the plate 20.

[0057] The outer zone heating element 25 is wired continuously from the second terminal 22a to the outer region of the plate 20 while forming a certain pattern such as a concentric circle, and then connected to the second terminal 22b. In this process, the outer zone heating element 25 can be bent at a certain position to surround the inner zone heating element 24, forming a concentric circle pattern (see FIG. 2), or can be bent at multiple connecting portions 23' to form multiple concentric circle patterns (see FIG. 3).

[0058] The multiple concentric circular patterns of the outer zone heating element 25 may include multiple concentric arc portions 25a-1, 25a-2, 25b-1, and 25b-2 extending along the circumferential direction of the plate 20. The multiple concentric arc portions 25a-1, 25a-2, 25b-1, and 25b-2 may also include multiple connecting portions 23' connecting adjacent arc portions 25a-1, 25a-2, 25b-1, and 25b-2 among the multiple concentric arc portions 25a-1, 25a-2, 25b-1, and 25b-2. Adjacent arc portions 25a-1, 25a-2, 25b-1, and 25b-2 may be connected by connecting portions 23' extending in the diameter direction.

[0059] The concentric arc portions 25a-1, 25a-2, 25b-1, and 25b-2 may have different diameters from one another, and the connecting portions 23′ may be aligned parallel to one another to form separation regions 26 in the plate 20 that extend in the radial direction of the plate 20 between them.

[0060] The external zone heating element 25 may include a first external heating portion 25a and a second external heating portion 25b. The first external heating portion 25a and the second external heating portion 25b may be configured to be line-symmetrical about the diameter of the plate 20 and 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 portions 25a-2 and 25b-2 are arc portions of the same diameter, but larger in diameter than the arc portions 25a-1 and 25b-1. The arc portion 25a-1 is connected to the arc portion 25a-2 by a connecting portion 23'. The arc portion 25b-1 is connected to the arc portion 25b-2 by a 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 disposed facing each other at a predetermined distance E. A separation region 26 where no external zone heating element 25 is wired may be formed on the plate 20 within an area defined by an imaginary line I formed by separating the connecting portions 23'. The separation region 26 may extend in the radial direction of the plate 20.

[0063] The spaced region 26 may be formed between the first external heat generating portion 25a and the second external heat generating portion 25b, and preferably may be formed in a region formed by aligning the plurality of connecting portions 23′ in parallel with one another and extending in the radial direction of the plate 20. The spaced region 26 may also 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 spaced region 26 may be formed by extending from the spaced region 26 formed in the inner region in the circumferential direction from the center of the plate 20.

[0064] The inner zone heating element 24 and the outer 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. The first passage 27 may also be formed parallel to the mounting surface 20a of the plate.

[0066] 2 to 4, when viewed from above the plate 20 in the thickness direction of 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. Furthermore, the first passage 27 may be formed adjacent to the separation region 26 formed between the conductive connection part 28 connected to the second terminal 22a and the conductive connection part 28 connected to the second terminal 22b.

[0067] The plate 20 may have multiple heating elements, for example, two heating elements 24 and 25 arranged independently of each other, as shown in Figures 2 and 3, or one single heating element 23 may be arranged over the entire area of ​​the plate 20, as shown in Figure 5.

[0068] Furthermore, the plate 20 may include a plurality of separation regions 26 and a plurality of first passages 27. The separation regions 26 and the first passages 27 may be formed at a plurality of angular positions in the circumferential direction. In this case, the plurality of first passages 27 may all have the same longitudinal length, or may be formed with different longitudinal lengths depending on the design.

[0069] FIG. 6 is a cross-sectional view taken along line CC in FIG.

[0070] 6, the first passages 27 are formed adjacent to and along the separation regions 26, so that the heating elements 23 do not need to be disposed above the first passages 27. By forming the first passages 27 in an area where the heating elements 23 are not densely packed, the heat generated by the heating elements 23 is prevented from being lost through the first passages 27, improving the temperature uniformity of the heater. In addition, cracks in weak portions of the plate 20 due to expansion and contraction of the heating elements 23 can be prevented.

[0071] On the other hand, FIGS. 7 and 8 are diagrams showing that heat loss and microcracks occur when the first passages are formed in an area where heating elements are densely packed.

[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] Also, as shown in FIG. 8, if the first passage 27 is formed adjacent to the heating element 23, microcracks 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 CC cross-sectional view of a plate according to yet 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 passage A portion 27a formed parallel to the mounting surface 20a of the plate, and a passage B portion 27b inclined relative to the mounting surface 20a.

[0076] The Bth passage portion 27b may be disposed at the circumferential end of the first passage 27, and may house the temperature measuring portion of the temperature sensor 60. The Bth passage portion 27b may be formed to be inclined toward the heating element 23, thereby minimizing the distance between the temperature measuring portion of the temperature sensor 60 and the heating element 23. In addition, the circumferential end of the Bth passage portion 27b may be positioned at the same height as the heating element 23 in the thickness direction of the plate 20, i.e., on the same plane, so that the temperature in the region between the heating element connecting portions 23′ can be measured more accurately.

[0077] 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 in the EE direction of FIG.

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

[0079] The A passage portion 27a and the B passage portion 27b may be in the form of a groove or hole extending long in the circumferential direction of the plate 20 so that a temperature sensor 60 such as a thermocouple can be inserted. The A passage portion 27a and the B passage portion 27b may have various cross-sectional shapes such as a circle or a square.

[0080] The plate 20 may be fabricated by joining a lower plate P1 and an upper plate P2, each having an A passage portion 27a and a B passage portion 27b formed therein. If the A passage portion 27a and the B passage portion 27b are not precisely 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 B passage portion 27b.

[0081] To facilitate alignment when joining the upper plate P2 and the lower plate P1, the B passage portion 27b can be machined into the shape of a cone, a polygonal pyramid such as a triangular pyramid or a square pyramid, a truncated cone, or a truncated polygonal pyramid, as shown in Fig. 11. By forming the cross-sectional area of ​​the end portion of the B passage portion 27b to be small in this way, the temperature measuring portion of the thermocouple inserted into the B passage portion 27b does not shake, thereby improving the temperature measurement accuracy.

[0082] When the upper plate P2 and the lower plate P1 are joined together, an outlet of the A-th passage portion 27a, which is a hole through which the temperature sensor 60 can pass, may be formed at one end of the A-th passage portion 27a formed in the lower plate P1. In addition, an entrance of the B-th passage portion 27b, which is a hole through which the temperature sensor 60 can pass, may be located at a position adjacent to the outlet of the A-th passage portion 27a.

[0083] The outlet of the A passage portion 27a and the inlet of the B passage portion 27b are in contact with each other, so that the A passage portion 27a and the B passage portion 27b can integrally form the first passage 27. In this case, even if the A passage portion 27a and the B passage portion 27b are not precisely aligned, the inlet area D2 of the B passage portion 27b can be made larger than the outlet area D1 of the A passage portion 27a to prevent a reduction in the space through which the temperature sensor 60 passes.

[0084] In addition, the extra space of the entrance area D2 of the B passage portion 27b, i.e., the space corresponding to (D2-D1), is positioned to extend away from the center of the plate 20, so that a temperature sensor 60 such as a thermocouple can be easily inserted into the B passage portion 27b. That is, the thermocouple inserted through the A passage portion 27a can be easily inserted along the inner wall of the B passage portion 27b without hitting the upper plate P2 at the entrance of the B passage portion 27b.

[0085] Furthermore, the B-th 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] In this way, by forming the inlet area D2 of the B passage portion 27b larger than the outlet area D1 of the A passage portion 27a, it is possible to allow for alignment errors in the radial direction (left and right direction in FIG. 10) of the plate 22 when assembling the plate 22. Furthermore, by forming the width of the B passage portion 27b larger than the width of the A passage portion 27a as shown in FIG. 12, it is also possible to assemble the plate 22 while allowing for alignment errors in the rotational direction (circumferential direction of the plate).

[0087] Figure 13 is a portion of the cross section taken along line BB in Figure 1. Reference will now be made to the cross section PC and plan view PU of the joint portion between the plate 20 and the shaft 50.

[0088] 13, the shaft 50 may be formed into a cylindrical shape with a wall having a predetermined thickness and an internal space (hollow) 55. A plurality of power supply rods (not shown) connected to 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, thereby allowing the plurality of power supply rods (not shown) and the thermocouple guide 70 to be fixed on the lower side.

[0089] Hereinafter, the configuration of the plate 20 including the heating element 23 and the first passage 27, the shaft 50, the thermocouple 60, etc. may be applied as described above in the same manner as in FIGS.

[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, the upper plate P2 may be formed with the B-passage portion 27b (optional), and the lower plate P1 may be formed with the A-passage portion 27a.

[0091] 13, the first passage 27 may include a C-passage portion 27c between the A-passage portion 27a and the upper end of the shaft 50, the C-passage portion 27c gradually narrowing from the upper end of the shaft 50 to the A-passage portion 27a. The C-passage portion 27c may be formed in the plate 20. When the lower plate P1 and the upper plate P2 are separated, the C-passage portion 27c may be formed in the lower plate P1, or may be formed to extend from the lower plate P1 to a portion of the upper plate P2.

[0092] By providing the C passage portion 27c, which gradually narrows from the upper end of the shaft 50 to the A passage portion 27a, the spatial volume of the thermocouple passage in the C passage portion 27c can be minimized compared to when the C passage portion 27c is a hexahedral passage due to the curvature of the plate 20. The distal temperature measuring portion of the temperature sensor 60 contacts the curved surface of the C passage portion 27c and is pushed and inserted into the A passage portion 27a. To facilitate insertion, the curved surface is formed into a round surface such as a disk, sphere, or oval that extends from the upper end of the shaft 50 to the A passage portion 27a. In other words, the space in the C passage portion 27c may be shaped like a portion of a curved shape such as a disk, sphere, or oval.

[0093] A temperature sensor 60 such as a thermocouple may be inserted into the first passage 27 of the plate 20 via a thermocouple guide 70 having a through-hole provided in the hollow 55 of the shaft 50. The thermocouple guide 70 is disposed within the hollow 55 of the shaft 50, with its upper end positioned to meet the C passage portion 27c. That is, the temperature sensor 60 such as a thermocouple may be positioned throughout the interior of the thermocouple guide 70, the C passage portion 27c, and the A passage portion 27a. As described above, the temperature sensor 60 may be inserted by pushing the temperature measuring portion at the end of the A passage portion 27a. Furthermore, if the B passage portion 27b is provided, the temperature measuring portion at the end of the temperature sensor 60 may be inserted by pushing the temperature measuring portion at the end of the B 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 C 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 C passage portion 27c, and the A passage portion 27a.

[0095] In a conventional method, the thermocouple guide is formed in a curved shape (not shown) and its end is brought close to the A-th passage portion 27a. However, in this case, it is difficult to bring the end of the thermocouple guide close to the A-th passage portion 27a. In addition, because the thermocouple guide is not fixed, the thermocouple may sway during the process of inserting and pushing the thermocouple into the shaft, reducing the success rate of insertion. Furthermore, in order to insert such a conventional curved thermocouple guide into the shaft, a large amount of machining space must be secured within the plate 20 so that the end of the thermocouple guide can be brought close to the A-th passage portion 27a. This machining space can reduce the temperature uniformity of the plate. Furthermore, heat loss occurs through the attached thermocouple guide, which can cause cracks in the plate and interfere with maintaining temperature uniformity.

[0096] Therefore, in the present invention, a linear thermocouple guide 70 is fixed within the shaft 50 to facilitate thermocouple insertion, and the C passage portion 27c is provided, which gradually narrows from the upper end of the shaft 50 to the A passage portion 27a. This curvature of the plate 20 minimizes the spatial volume of the thermocouple passage in the C passage portion 27c compared to when the C passage portion 27c is a hexahedral passage. The temperature measuring portion at the end of the temperature sensor 60 contacts and is pushed into the A passage portion 27a along the curved surface of the C passage portion 27c, greatly increasing the insertion success rate.

[0097] The advantages of the structure of the present invention in which the linear thermocouple guide 70 is fixed in the shaft 50 and the curved surface of the C-th passage portion 27c is utilized will be described in more detail below.

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

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

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

[0101] 2) Effect of removing thermocouple guide

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

[0103] Furthermore, by minimizing heat loss due to the thermocouple guide 70, the temperature uniformity of the plate 20 can be improved and cracks caused by sudden heat loss can be prevented.

[0104] 3) Effect of improving thermocouple insertion stability

[0105] In the improved structure of the present invention, the thermocouple bends due to the curvature of the plate 20 when inserted, and the fixed thermocouple guide 70 supports the thermocouple so that it can bend along the curvature of the plate 20.

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

[0107] - In addition, the smaller the radius of curvature of the curved portion of the plate 20, the greater the force acting on the plate 20 during insertion. However, due to the improved fixing force of the thermocouple guide 70, the radius of curvature of the insertable plate 20 can be reduced compared to when the thermocouple guide 70 is not fixed, and the same effect can be achieved.

[0108] - In addition, while using a ceramic heater in a semiconductor process, there was a problem in the past where 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 even during use, improving durability.

[0109] Meanwhile, in the present invention, the end of the thermocouple guide 70 may be inserted and fixed in a groove of the plate 20 connected to the Cth 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 in a corresponding groove of the plate 20, but as will be described later, the thermocouple guide 70 may be inserted and fixed in a groove of the plate 20 or the lower plate P1 in various ways according to various embodiments.

[0110] Figure 14 is an enlarged view showing another embodiment of the joining portion between the plate 20 and the shaft 50 in the cross section BB of Figure 1. Reference will now be made to the cross section PC and the plan view PU.

[0111] 14 , a flat portion 71 at the end of the thermocouple guide 70 may be inserted into and fixed in the groove 31 of the plate 20 connected to the C-th passage portion 27c. The flat portion 71 is inserted into the groove 31 of the plate 20 to fix the thermocouple guide 70. The flat portion 71 has a predetermined shape, such as a rectangular plate shape, that corresponds to the shape of the groove 31, allowing for a larger insertion area and improved fixing strength. Here, the rectangular plate-shaped flat portion 71 has a portion that extends further on one side of the end of the thermocouple guide 70 than the diameter of the body of the thermocouple guide 70, and a portion that extends further on the other side. The flat portion 71 may be an integrated part formed into the desired shape by machining the end of the material of the thermocouple guide 70, or it may be formed separately and joined to the end of the thermocouple guide 70 by welding, ceramic bonding, or the like.

[0112] Figure 15 is an enlarged view showing still another embodiment of the joining portion between the plate 20 and the shaft 50 in the cross section BB of Figure 1. Reference will now be made to the cross section PC and the plan view PU.

[0113] 15, the embedded protrusion 71-1 at the end of the thermocouple guide 70 may be inserted into and fixed to the C passage portion 27c and the groove 31 of the plate 20. The embedded protrusion 71-1, which fills the insertion groove 31 of the plate 20 and the C passage portion 27c, increases the insertion area and is inserted into the inside of the C passage portion 27c, thereby improving the fixing force and the insertion success rate. The embedded protrusion 71-1 may be an integrated part formed into the desired shape by processing the end of the material of the thermocouple guide 70, or may be formed separately and joined to the end of the thermocouple guide 70 by welding, ceramic bonding, or the like.

[0114] Figure 16 is an enlarged view showing still another embodiment of the joining portion between the plate 20 and the shaft 50 in the cross section BB of Figure 1. Reference will now be made to the cross section PC and the plan view PU.

[0115] 16, the flat portion 72 at the end of the thermocouple guide 70 may be inserted into and fixed in the groove 32 of the plate 20 connected to the C-th passage portion 27c. The thermocouple guide 70 is fixed by inserting the flat portion 72 into the groove 32 of the plate 20. A flat portion 72 having a predetermined shape, such as a rectangular plate shape, that corresponds to the shape of the groove 32 can increase the insertion area and improve the fixing force. Here, the rectangular plate-shaped flat portion 71 is changed to a square plate shape. The flat portion 72 may be an integrated part formed by processing the end of the material of the thermocouple guide 70 into the desired shape, or it may be formed separately and joined to the end of the thermocouple guide 70 by welding, ceramic bonding, or the like.

[0116] 14 and 16, the flat portions can be embodied in various shapes, such as a disk, various rectangular plates, an oval plate, or a star-shaped plate, at the end of the thermocouple guide 70. The flat portions 71 and 72 of such a thermocouple guide 70 can increase the area inserted into the plate 20 and improve the fixing force.

[0117] Figure 17 is an enlarged view showing still another embodiment of the joining portion between the plate and the shaft in the cross section BB of Figure 1. Reference will now be made to the cross section PC and the plan view PU.

[0118] 17, a protrusion 73 at the end of the thermocouple guide 70 may be inserted into and fixed to the groove 33 of the plate 20 connected to the C-th passage portion 27c. Here, the cross-sectional shape of the protrusion 73 and the corresponding groove 33 of the plate 20 may be various shapes such as a circle, a rectangle, an oval, a star, etc. The protrusion 73 of the thermocouple guide 70 can also improve fixing strength so as to reduce shaking.

[0119] Figure 18 is an enlarged view showing still another embodiment of the joining portion between the plate and the shaft in the cross section BB of Figure 1. Reference will now be made to the cross section PC and the plan view PU.

[0120] 18, groove 74 at the end of thermocouple guide 70 may be inserted into groove 34 of plate 20 connected to C-th passage portion 27c and fixed thereto. Here, the cross-sectional shapes of groove 74 and the corresponding groove 34 of plate 20 may be various shapes such as circular, rectangular, elliptical, star-shaped, etc. Groove 74 of such thermocouple guide 70 can also improve fixing force so as to reduce shaking.

[0121] Figure 19 is an enlarged view showing still another embodiment of the joining portion between the plate and the shaft in the cross section BB of Figure 1. Reference will now be made to the cross section PC and the plan view PU.

[0122] 19, the threaded portion 75 (e.g., male thread) at the end of the thermocouple guide 70 may be fastened (screwed) to the threaded portion 39 (e.g., female thread) of the groove 35 of the plate 20 that is connected to the C-th passage portion 27c, thereby securing the thermocouple guide 70. The threaded portion 75 of such a thermocouple guide 70 can also improve the securing force so as to reduce shaking.

[0123] As described above, the present invention has been described using specific details such as specific components, limited embodiments, and drawings. However, these are provided merely to facilitate a more comprehensive understanding of the present invention, and the present invention is not limited to the above embodiments. Those skilled in the art will appreciate that various modifications and variations may be made without departing from the essential characteristics of the present invention. Therefore, the concept of the present invention should not be limited to the described embodiments, and should be construed as falling within the scope of the following claims, as well as any technical concepts equivalent to or modified from the scope of the claims. Furthermore, the above embodiments may be combined with each other as necessary. [Explanation of symbols]

[0124] 10. Ceramic heater 20 plates 23 Heating element 26 Separate Area 27 1st aisle 27a Passage A section 27b No. B aisle section 27c No. C passage section 50 shaft

Claims

1. a plate having a heating element and a first passage; a shaft having a hollow; 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 of the shaft, the C-passage portion gradually narrowing from the upper end of the shaft to the A-passage portion; a thermocouple guide disposed within the hollow of the shaft, the upper end of which meets the C passage portion; The thermocouple is located inside the thermocouple guide, in the C passage portion, and in the A passage portion.

2. 2. The ceramic heater according to claim 1, wherein an end of the thermocouple guide is inserted into and fixed to a groove in the plate that is connected to the C passage portion.

3. 2. The ceramic heater according to claim 1, wherein the flat portion at the end of the thermocouple guide is inserted into and fixed to a groove in the plate that is connected to the C passage portion.

4. 2. The ceramic heater according to claim 1, wherein the recessed protrusions at the ends of the thermocouple guide are inserted into and fixed to the C passage portion and the grooves of the plate.

5. 2. The ceramic heater according to claim 1, wherein a protruding portion at an end of the thermocouple guide is inserted into and fixed to a groove in the plate that is connected to the C passage portion.

6. 2. The ceramic heater according to claim 1, wherein a groove portion at an end of the thermocouple guide is inserted into and fixed to a groove of the plate connected to the C passage portion.

7. 2. The ceramic heater according to claim 1, wherein a threaded portion at an end of said thermocouple guide is fastened and fixed to a threaded portion of a groove in said plate that is connected to said C passage portion.

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