Ceramic base

Abstract

The present invention relates to a ceramic susceptor, and the susceptor according to the present invention may comprise: an insulating plate provided with a heating element, and a shaft joined to the lower part of the insulating plate; the heating element may include a first heating element pattern including a first resistance portion and a first connection portion connected between the first terminal pair; when the first resistive portion is projected onto a plane of the insulating plate, a first central resistive portion may be included within a diameter region smaller than a joint portion of the insulating plate and the shaft.

Description

Technical Field

[0001] The present invention relates to a ceramic base, and more particularly, to a ceramic base that improves temperature uniformity and is used to improve the lifespan of a heater pattern. Background Art

[0002] Generally, semiconductor devices or display devices are manufactured by patterning after sequentially laminating a plurality of thin film layers including a dielectric layer and a metal layer on a glass substrate, a flexible substrate, or a semiconductor wafer substrate. These thin film layers are sequentially deposited on the substrate by a Chemical Vapor Deposition (CVD) process or a Physical Vapor Deposition (PVD) process. As the CVD process includes a Low Pressure CVD (LPCVD) process, a Plasma Enhanced CVD (PECVD) process, a Metal Organic CVD (MOCVD) process, and the like. A ceramic base is provided on such CVD devices and PVD devices, which is used to support a glass substrate, a flexible substrate, or a semiconductor wafer substrate, etc., and is used to generate a predetermined heat or generate plasma through a Radio Frequency (RF) electrode. For precise processes such as the miniaturization of wirings of semiconductor devices, the ceramic base is widely used in plasma deposition processes, etc., according to accurate temperature control and heat treatment requirements, etc. In addition, the ceramic base is used for an etching process or a baking process of a photoresist of a thin film layer formed on a semiconductor wafer substrate for the purpose of plasma formation or substrate heating.

[0003] An ordinary ceramic base includes a heating element for heating function located between ceramic materials. In the ceramic base structure, the heating element receives power and generates heat to heat a semiconductor wafer substrate, etc. In order to improve the yield through a stable semiconductor process, the temperature uniformity of the substrate is important.

[0004] Figure 1 FIG. shows a heater pattern of a conventional ceramic base.

[0005] Refer to Figure 1, existing ceramic bases usually have a heating element pattern 10, and the heating element pattern 10 extends in an arc shape from the terminal pair (terminal 10a, terminal 10b) at the center part on the same plane. The existing heating element pattern 10 includes a hairpin section 20, and the hairpin section 20 is a section that is sharply bent for folding in a narrow area at the center part. That is, the hairpin section 20 near the terminal pair (terminal 10a, terminal 10b) is in a sharp turning shape, and the radius of curvature of the hairpin section 20 is smaller than the radius of curvature of the adjacent folded part.

[0006] However, such a hairpin section 20 is an area with a high heating density due to a high pattern density per unit area, and thus cracks are likely to occur due to long-term use. This is caused by thermal stress due to the difference in the thermal expansion rate of the heating element embedded in the ceramic material. In semiconductor processes, especially for the ceramic base used in the deposition process, as it is exposed to a repeated heat cycle environment, cracks gradually occur on the surface of the ceramic base, which can lead to a reduction in function and thus make it unusable. Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] Therefore, the present invention is proposed to solve the above problems, and the object of the present invention is to provide a ceramic base that forms a heating element pattern without a hairpin section in the central part of the base plate with a high embedding density of the heating element, thereby improving the temperature uniformity of the entire area of the upper surface of the base and being used to improve the life of the heater pattern.

[0009] Means for Solving the Problems

[0010] First, to summarize the features of the present invention, according to a base of one aspect of the present invention for achieving the above object, it may include: an insulating plate provided with a heating element; and a shaft joined to the lower part of the insulating plate; the heating element may include a first heating element pattern, and the first heating element pattern includes a first resistance part and a first connection part connected between a first terminal pair. When the first resistance part is projected onto the plane of the insulating plate, it may include a first central resistance part located within a diameter area smaller than the joint part of the insulating plate and the shaft.

[0011] The first resistance part may include: a plurality of arc parts extending in the circumferential direction, and a plurality of folded parts for connecting the arc parts; the curve of the first central resistance part may be formed in such a way as to intersect with the extension line of a virtual straight line passing through the separated space between adjacent folded parts.

[0012] The first resistance portion may include: a plurality of arc portions extending in the circumferential direction, and a plurality of folding portions for connecting the arc portions; the curve of the first central resistance portion may be formed in a manner that intersects a virtual extension line extending from the folding portion closest to the first central resistance portion.

[0013] In the curve of the first central resistance portion, the radius of curvature of a part close to any one of the first terminal pairs may be greater than the radius of curvature in the folding portion of the first resistance portion.

[0014] The radius of curvature of a part close to any one of the first terminal pairs may be more than twice the maximum radius of curvature of the folding portion of the first resistance portion.

[0015] In the curve of the first central resistance portion, the radius of curvature of a part close to any one of the first terminal pairs may be greater than the radius of curvature of the folding portion closest to the folding portion in the first resistance portion.

[0016] In the curve of the first central resistance portion, the radius of curvature of a part close to any one of the first terminal pairs may be greater than the radius of curvature of the folding portion closest to the folding portion in the first resistance portion; in the curve of the second central resistance portion, the radius of curvature of a part close to any one of the second terminal pairs may be greater than the radius of curvature of the folding portion closest to the folding portion in the second resistance portion.

[0017] The first terminal pair may be located within a diameter region smaller than the joint portion of the insulating plate and the shaft.

[0018] The heating element may include a second heating element pattern, and the second heating element pattern includes a second resistance portion and a second connection portion connected between the second terminal pairs; when the first resistance portion and the second resistance portion are projected onto the plane of the insulating plate, the second central resistance portion of the second resistance portion located within a diameter region smaller than the joint portion of the insulating plate and the shaft may be included.

[0019] The second resistance portion may include: a plurality of arc portions extending in the circumferential direction, and a plurality of folding portions for connecting the arc portions; at least any one of the curves of the first central resistance portion and the second central resistance portion may be formed in a manner that intersects an extension line of a virtual straight line passing through the separated spaces between adjacent folding portions.

[0020] The adjacent folding portions may include one of the folding portions of the first resistance portion facing each other and one of the folding portions of the second resistance portion.

[0021] The second resistor portion may include: a plurality of arc portions extending in a circumferential direction, and a plurality of folding portions for connecting the arc portions; at least any one of the curves of the first central resistor portion and the curve of the second central resistor portion may be formed in a manner intersecting with a virtual extension line extending from the folding portion of the first central resistor portion closest to the first central resistor portion or the second central resistor portion.

[0022] The second resistor portion may include: a plurality of arc portions extending in a circumferential direction, and a plurality of folding portions for connecting the arc portions; at least any one of the curves of the first central resistor portion and the curve of the second central resistor portion may be formed in a manner intersecting with a virtual extension line extending from the folding portion of the second central resistor portion closest to the first central resistor portion or the second central resistor portion.

[0023] The second resistor portion may include: a plurality of arc portions extending in a circumferential direction, and a plurality of folding portions for connecting the arc portions; at least any one of the curves of the first central resistor portion and the curve of the second central resistor portion may be formed in a manner intersecting with respective virtual extension lines extending from the folding portion of the first central resistor portion and the folding portion of the second central resistor portion closest to the first central resistor portion and the second central resistor portion, respectively.

[0024] Among the curves of the first central resistor portion and the curve of the second central resistor portion, the curvature radii of portions close to any one of the respective terminal pairs may be greater than the curvature radii in the folding portions of the first resistor portion and the second resistor portion.

[0025] The curvature radius of a portion close to any one of the respective terminal pairs may be more than twice the maximum curvature radius of the folding portions of the first resistor portion and the second resistor portion.

[0026] The second terminal pair may be located within a diameter region smaller than the joint portion of the insulating plate and the shaft.

[0027] Advantages of the Invention

[0028] According to the ceramic base of the present invention, a heating element pattern without hairpin sections can be formed in the central portion of the base plate with a high embedding density of the heating element, thereby improving the temperature uniformity of the entire area of the upper surface of the base and significantly extending the life of the heater pattern. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] To facilitate understanding of the present invention, the embodiments of the present invention are provided as part of the detailed description, and are used together with the detailed description to illustrate the technical concept of the present invention.

[0030] Figure 1It is a figure showing the heating element pattern of an existing ceramic base.

[0031] Figure 2 It is a schematic cross-sectional view of the ceramic base according to an embodiment of the present invention.

[0032] Figure 3A It is an example of the heating element pattern of the ceramic base of the present invention.

[0033] Figure 3B It is used to illustrate Figure 1 the sharp turn part of the curve of the existing resistance part.

[0034] Figure 3C It is a figure used to illustrate the curve change of the central resistance part 910 of the present invention.

[0035] Figure 4A It is an example of the 2-zone setting structure of the heating element pattern of the ceramic base of the present invention.

[0036] Figure 4B It is another example of the 2-zone setting structure of the heating element pattern of the ceramic base of the present invention.

[0037] Figure 5A It is Figure 4A an enlarged view of the PP1 part.

[0038] Figure 5B It is Figure 4B an enlarged view of the PP2 part.

[0039] Explanation of reference numerals

[0040] 110: Insulating board

[0041] 114: Heating element

[0042] 71a, 71b, 81a, 81b, 82a, 82b: Terminals

[0043] 85: Arc part

[0044] 86: Folding part

[0045] 91: Resistance part

[0046] 91-1: First resistance part

[0047] 91-2: Second resistance part

[0048] 92: Connection part

[0049] 92-1: First connection part

[0050] 92-2: Second connection part

[0051] 910: Central resistance part

[0052] 910-1: First central resistance part

[0053] 910-2: Second central resistance part Detailed implementation manners

[0054] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. At this time, in each of the drawings, the same constituent elements are denoted by the same reference numerals as much as possible. In addition, detailed descriptions of known functions and / or structures are omitted. The content disclosed below focuses on the parts required to understand the operations of various embodiments, and descriptions of elements that make the gist of the description unclear are omitted. In addition, some constituent elements in the drawings may be enlarged or omitted, or schematically shown. The sizes of the respective constituent elements do not exactly reflect the actual sizes, and thus the content described herein is not limited to the relative sizes or spacings of the constituent elements shown in each of the drawings.

[0055] In the process of describing the embodiments of the present invention, when it is determined that a detailed description of the known technology related to the present invention unnecessarily confuses the gist of the present invention, the detailed description thereof will be omitted. Moreover, the following terms are defined in consideration of the functions in the present invention and may be changed according to the intentions or conventions of users and operators. Therefore, they should be defined based on the entire content of this specification. The terms used in the detailed description are only for describing the embodiments of the present invention and should not be restrictive. Unless otherwise clearly stated, expressions in the form of a single quantity include the meaning of the form of a plurality of quantities. In the course of this description, expressions such as "including" or "having" are used to indicate certain characteristics, numbers, steps, actions, elements, parts of these, or combinations, and should not be construed as excluding the existence or possibility of one or more other characteristics, numbers, steps, actions, elements, parts of these, or combinations other than those described.

[0056] In addition, terms such as "first" and "second" may be used to describe various constituent elements, but the constituent elements are not limited to such terms, and such terms are only for the purpose of distinguishing one constituent element from other constituent elements.

[0057] Figure 2 is a schematic cross-sectional view of a ceramic base 100 according to an embodiment of the present invention.

[0058] Refer to Figure 2 , a (ceramic) base 100 according to an embodiment of the present invention includes an insulating plate 110 and a shaft 120.

[0059] A ceramic base 100 according to an embodiment of the present invention is a semiconductor device for a semiconductor process using plasma, which is used to support a substrate to be processed (such as a semiconductor wafer, a glass substrate, a flexible substrate, etc.) for various purposes and heat the substrate to be processed at a predetermined temperature, or for plasma enhanced chemical vapor deposition, dry etching, etc.

[0060] The insulating plate 110 may be configured to be disposed (embedded) at a predetermined interval between ceramic materials for generating a plasma or an electrostatic chuck functional electrode 112 and / or a heating element (electrode) 114 for heating the substrate. The insulating plate 110 may be configured to be able to perform substrate heating using the heating element 114 and / or a semiconductor process using plasma by means of the electrode 112 while stably supporting the substrate to be processed.

[0061] Although not shown in the ceramic base 100 of the present invention, the electrode 112 can be used to generate plasma, and one or more chuck electrodes with an electrostatic chuck function can be further provided to support the substrate 11 placed on the insulating plate 110. For example, one or more chuck electrodes can also be disposed (embedded) at a predetermined interval above or below the electrode 112 or the heating element 114.

[0062] The insulating plate 110 can be formed into a plate-like structure with a predetermined shape. As an example, the insulating plate 110 can be formed into a circular plate-like structure, but it is not necessarily limited thereto. Among them, the ceramic material can be at least one of Al2O3, Y2O3, Al2O3 / Y2O3, ZrO2, autoclaved lightweight concrete (AlC), TiN, AlN, TiC, MgO, CaO, CeO2, TiO2, BxCy, BN, SiO2, SiC, YAG, mullite, and AlF3, and preferably aluminum nitride (AlN). In addition, each ceramic powder can selectively contain about 0.1% to 10% of yttrium oxide powder, and preferably contain about 1% to 5% of yttrium oxide powder.

[0063] The shaft 120 has a hollow shape with a through hole and is joined or coupled to the lower surface of the insulating plate 110. The shaft 120 can be formed of the same ceramic material as the insulating plate 100 and joined or coupled to the insulating plate 100.

[0064] The electrode 112 or one or more chuck electrodes may be composed of tungsten (W), molybdenum (Mo), silver (Ag), gold (Au), niobium (Nb), titanium (Ti), aluminum nitride (AlN), or their alloys, preferably composed of molybdenum (Mo). The electrode 112 may be connected to an RF (Radio) power supply or grounded through a connecting rod 121 built into the hollow shaft 120, and one or more chuck electrodes may be connected to a power supply for driving the chuck electrode (DC power supply or AC power supply) through other connecting rods built into the hollow shaft 120. The electrode 112 has a wire type or sheet type mesh structure. Among them, the mesh structure is a mesh structure formed by the intersection of a plurality of metals arranged in the first direction and a plurality of metals arranged in the second direction.

[0065] The heating element 114 is formed of tungsten (W), molybdenum (Mo), or their alloys or carbides, etc., and has a high melting point and high resistance. The heating element 114 may be formed in the form of a plate-like coil based on a heating wire (or resistance wire or heating electrode), etc. In addition, for precise temperature control, the heating element 114 may also be formed in a multi-layer structure. Such a heating element 114 may be connected to a power supply through a connecting rod 123 built into the hollow shaft 120 in a semiconductor manufacturing process, and in order to perform a smooth deposition process, etching process, etc., the heating element 114 may perform the function of heating a substrate to be processed on the insulating plate 110 at a predetermined constant temperature.

[0066] As Figures 3A to 5B shown, in the ceramic base 100 of an embodiment of the present invention, the heating element 114 formed of a heating wire (or resistance wire) forms a heating element pattern without a hairpin section in the central portion SR of the base plate with a high embedding density, that is, in a diameter region SR smaller than the joint portion of the insulating plate 110 and the shaft 120, as Figure 1 shown, so as to improve the temperature uniformity of the entire area of the upper surface of the base and significantly extend the life of the heating pattern.

[0067] That is, the heating element pattern located in the diameter region SR smaller than the joint portion of the insulating plate 110 and the shaft 120 may be formed by a curve bent by more than 90 degrees (for example, 90 to 270 degrees) without a sharp turn. Among them, a sharp turn may include a case where the curvature radius decreases and then increases, or increases and then decreases.

[0068] Hereinafter, with reference to Figures 3A to 4B , the above structure of the present invention will be specifically described.

[0069] Figure 3A is an example of the heating element 114 pattern of the ceramic base 100 of the present invention.

[0070] With reference toFigure 3A The heating element 114 may include a heating element pattern, and the heating element pattern may include a resistance portion 91 connected between a first terminal pair (terminals 71a and 71b) and a connection portion 92. The resistance portion 91 may include a plurality of arc portions 85 extending in the circumferential direction and a plurality of folding portions 86 for connecting the arc portions.

[0071] The connection portion 92 is a connection line portion for electrically connecting the two ends of the resistance portion 91 to the first terminal pair (terminals 71a and 71b). The resistance portion 91 and the connection portion 92 are formed of a material with a high resistance, such as tungsten (W), molybdenum (Mo), or their alloys or carbides. The resistance portion 91 is a portion that increases the resistance by processing the above-described material into a coil shape (in some cases, it may also be a sawtooth shape or a zigzag shape, etc.) to increase the moving distance of electrons.

[0072] When the resistance portion 91 is projected onto the plane of the insulating plate 110, a central resistance portion 910 located within a diameter region SR smaller than the joint portion of the insulating plate 110 and the shaft 120 may be formed by a curve bent at more than 90 degrees (e.g., 90 to 270 degrees) without a sharp turn. Preferably, the first terminal pair (terminals 71a and 71b) is also located within the diameter region SR smaller than the joint portion of the insulating plate 110 and the shaft 120, but in some cases, it may also be located in other regions.

[0073] That is, the curve of the central resistance portion 910 refers to a curve of the resistance portion 91 pattern located within the diameter region SR smaller than the joint portion of the insulating plate 110 and the shaft 120 without a sharp turn. Since a sharp turn interval as described above causes a hairpin interval as Figure 1 shown, it is not conducive to temperature uniformity and the lifespan of the heating element pattern. Therefore, the curve of the central resistance portion 910 may have no sharp turn, that is, when the curve includes bending points B1 and B2 of the curve, the extension lines before and after the bending points B1 and B2 of the curve are bent at more than 90 degrees (e.g., 90 to 270 degrees).

[0074] Figure 3B is a diagram for explaining Figure 1 the sharp turn portion of the curve of the existing resistance portion. Referring to Figure 3B , as Figure 1 shown, the resistance portion at the center of the existing plate has a sharp turn shape, and the curvature radius of the bending point A1 of the curve in the hairpin interval near the terminal pair (terminals 10a and 10b) is smaller than the curvature radius of the adjacent folding portion. For example, such a sharp turn shape may be a shape in which the extension lines A1-1 and A1-2 before and after the bending point A1 are bent at less than 90 degrees. This is a region with a high heating density due to a high pattern density per unit area, so cracks are likely to occur due to long-term use.

[0075] Figure 3C is a diagram for explaining the curve change of the central resistance portion 910 of the present invention. Referring to Figure 3C , in the curve of the central resistance portion 910 of the present invention, for one or more bending points B1, B2 of the curve, the extension lines before and after it intersect at 90 degrees or more (for example, 90 to 270 degrees) and there is no portion with a sharp bend, so it can be designed without a sharp turn interval. For example, the extension lines before and after the bending point B1 can be the first extension line for connecting a terminal (for example, terminal 71a) or the previous bending point (not shown) to the bending point B1 and the second extension line for connecting the bending points B1, B2. In addition, for the bending point B2, the extension lines before and after can be the first extension line for connecting the bending points B1, B2 and the second extension line for connecting the bending point B2 to the next bending point (not shown).

[0076] Furthermore, preferably, as shown by the point PL in Figure 3A , the curve of the central resistance portion 910 located within the diameter region SR smaller than the joint portion of the insulating plate 110 and the shaft 120 is formed in such a way as to intersect the extension line of the straight line LL more than once, where the straight line LL is a virtual straight line passing through the separation space between adjacent folded portions 86 of the resistance portion 91. The separation space between the adjacent folded portions 86 includes the separation space between at least a pair of opposing folded portions 86. However, as shown in the figure, the opposing folded portions 86 do not necessarily have to be formed symmetrically with respect to a line as long as they are separated. In Figure 3A , the separation space between the adjacent folded portions 86 is shown as the separation space between 3 pairs of opposing folded portions 86.

[0077] As described above, when there are the intersection points PL, PL1, PL2, the empty space without the resistance portion 91 pattern between the folded portions 86 does not extend into the diameter region SR smaller than the joint portion of the insulating plate 110 and the shaft 120. Therefore, in this case, the temperature uniformity around can be improved by the resistance portion 91 pattern at the intersection points PL, PL1, PL2.

[0078] Figure 4A is an example of the two - zone setting structure of the heating element 114 pattern of the ceramic base 100 of the present invention.

[0079] Figure 4B is another example of the two - zone setting structure of the heating element 114 pattern of the ceramic base 100 of the present invention.

[0080] Figure 4A and Figure 4B show the setting positions of different first central resistance portions 910 - 1 and second central resistance portions 910 - 2.

[0081] Reference Figure 4A and Figure 4B ,The heating element 114 may include: a first heating element pattern 411 including a first resistance portion 91-1 and a first connection portion 92-1 connected between a first terminal pair (terminals 81a, 81b); and a second heating element pattern 412 including a second resistance portion 91-2 and a second connection portion 92-2 connected between a second terminal pair (terminals 82a, 82b). The resistance portions (the first resistance portion 91-1, the second resistance portion 91-2) may each include a plurality of arc portions 85-1, 85-2 extending in the circumferential direction and a plurality of folding portions 86-1, 86-2 for connecting the arc portions.

[0082] The connection portions (the first connection portion 92-1, the second connection portion 92-2) are respectively connection line portions of the terminal pairs (terminals 81a and 81b, terminals 82a and 82b) for electrically connecting both ends of the resistance portions (the first resistance portion 91-1, the second resistance portion 91-2). The resistance portion 91 and the connection portion 92 are formed of a material having a large resistance such as tungsten (W), molybdenum (Mo), or their alloy or carbide, and the resistance portion 91 is a portion that increases the resistance by processing the above-described material into a coil shape (optionally, a serrated shape or a zigzag shape, etc.) to increase the moving distance of electrons.

[0083] When the first resistance portion 91-1 and the second resistance portion 91-2 are respectively projected onto the plane of the insulating plate 110, a first central resistance portion 910-1 of the first resistance portion 91-1 and a second central resistance portion 910-2 of the second resistance portion 91-2 located within a diameter region SR smaller than the joint portion of the insulating plate 110 and the shaft 120 may each be formed of a curve without a sharp turn or a straight portion. Preferably, the first terminal pair (terminals 81a, 81b) and the second terminal pair (terminals 82a, 82b) are located within a region diameter region SR smaller than the joint portion of the insulating plate 110 and the shaft 120, but optionally, they may also be located in other regions.

[0084] That is, the curves of the central resistance portions (the first central resistance portion 910-1, the second central resistance portion 910-2) may be formed of curves that are bent by more than 90 degrees (e.g., 90 to 270 degrees) without a sharp turn in the patterns of the respective resistance portions (the first resistance portion 91-1, the second resistance portion 91-2) located within the diameter region SR smaller than the joint portion of the insulating plate 110 and the shaft 120.

[0085] Furthermore, preferably, as Figure 4AAs shown by the point PL, one or more (e.g., the second central resistance part 910-2) of the central resistance parts (the first central resistance part 910-1, the second central resistance part 910-2) located in the region SR of the joint part smaller than the axis 120 form the curve in such a way as to intersect the extension line of the straight line LL more than once. The straight line LL is a virtual straight line passing through the separation space between adjacent folded parts 86-1, 86-2 of the resistance parts (the first resistance part 91-1, the second resistance part 91-2). The separation space between adjacent folded parts 86-1, 86-2 of the resistance parts (the first resistance part 91-1, the second resistance part 91-2) includes at least a pair of separation spaces between the folded part 86-1 of the first resistance part 91-1 and the folded part 86-2 of the second resistance part 91-2 facing each other. However, as shown in the figure, the facing folded parts 86-1, 86-2 do not necessarily have to be formed in line symmetry as long as they are separated. In Figure 4A the separation space between the adjacent folded parts 86-1, 86-2 is shown as the separation space between 3 pairs of facing folded parts 86.

[0086] Figure 5A is Figure 4A an enlarged view of the PP1 part of

[0087] Refer to Figure 5A As shown by the point PL1, at least any one of the curves of the central resistance parts (the first central resistance part 910-1, the second central resistance part 910-2) located in the region SR of the joint part smaller than the axis 120 can also be formed in such a way as to intersect the extension line LL1. The extension line LL1 is a virtual line extending from the folded part 86-11 of the first central resistance part 910-1 closest to the first central resistance part 910-1 or the second central resistance part 910-2. In addition, at least any one of the curves of the central resistance parts (the first central resistance part 910-1, the second central resistance part 910-2) located in the region SR of the joint part smaller than the axis 120 can also be formed in such a way as to intersect the extension line LL2 as shown by the point PL2. The extension line LL2 is a virtual line extending from the folded part 86-21 of the second central resistance part 910-2 closest to the first central resistance part 910-1 or the second central resistance part 910-2.

[0088] Figure 5B is Figure 4B an enlarged view of the PP2 part of

[0089] Refer to Figure 5B, at least any one of the curves in the central resistance portions (the first central resistance portion 910-1, the second central resistance portion 910-2) located in the region SR of the joint portion smaller than the axis 120 may also be formed in such a way that the extension lines LL1 and LL2 intersect as shown by the points PL1 and PL2. The extension lines LL1 and LL2 are virtual lines extending from the folded portions 86-11 of the first central resistance portion 910-1 and the folded portions 86-21 of the second central resistance portion 910-2 that are closest to the first central resistance portion 910-1 and the second central resistance portion 910-2 respectively.

[0090] As described above, when there are intersection points PL, PL1, and PL2 as described above, the empty space without the resistor portion 91 pattern between the folded portions 86 does not extend into the region SR of the joint portion smaller than the axis 120. Therefore, in this case, the temperature uniformity around can be improved by the resistor portion 91 pattern at the intersection points PL, PL1, and PL2.

[0091] In addition, in Figure 5A and Figure 5B , the curves of the central resistance portions (the first central resistance portion 910-1, the second central resistance portion 910-2) located in the region SR of the joint portion smaller than the axis 120 each include: a curvature radius RC1 (for example, R7) interval near the terminal of the central resistance portion, a curvature radius RC2 (for example, R2.5) interval between the central resistance portion and the folded portion 86-1, and a curvature radius RC3 (for example, R3.5) interval between the other arc portion 85 and the folded portion 86-1, etc. Among them, in R7, R3.5, and R2.5, the numerical unit of each radius of curvature is mm.

[0092] Among them, for the sake of convenience of explanation, the curvature radii of the first resistor portion 91-1 and the first central resistance portion 910-1 are illustrated, but this relationship can also be applied to the curvature radii of the second resistor portion 91-2 and the second central resistance portion 910-2. Furthermore, this relationship can also be applied to the first resistor portion 91-1 and the first central resistance portion 910-1 and the second resistor portion 91-2 and the second central resistance portion 910-2.

[0093] Similarly, this relationship can also be applied to Figure 3A the resistor portion 91 and the central resistance portion 910 in Figure 3AAmong them, in the region SR within the bonding portion smaller than the axis 120, at least any one of the curves in the central resistance portion 910 connected to the first terminal pair (terminal 71a, terminal 71b) includes: a curvature radius RC1 (e.g., R7) interval near the terminal side (e.g., terminal 71a) of the central resistance portion 910, a curvature radius RC2 (e.g., R2.5) interval between the central resistance portion 910 and the folding portion 86, and a curvature radius RC3 (e.g., R3.5) interval between the other arc portion 85 and the folding portion 86, etc.

[0094] In other words, in the respective curves of the central resistance portions (the first central resistance portion 910-1, the second central resistance portion 910-2) located in the region SR within the bonding portion smaller than the axis 120, the partial curvature radius (e.g., R7) near any one of the terminal pairs (terminal 81a and terminal 81b, terminal 82a and terminal 82b) can be greater than the curvature radii (e.g., R2.5, R3.5, etc.) in all other folding portions 86-1, 86-2. At this time, the partial curvature radius (e.g., R7) near any one of the terminal pairs (terminal 81a and terminal 81b, terminal 82a and terminal 82b) can be more than twice the maximum curvature radius (e.g., R3.5) in all other folding portions 86-1, 86-2.

[0095] Furthermore, in the curve of the first central resistance portion 910-1, the partial curvature radius (e.g., RC1 = R7) near any one of the first terminal pair (terminal 81a, terminal 81b) can be greater than the curvature radius (e.g., RC2 = R2.5) of the folding portion closest to the first resistance portion 91-1. Similarly, in the curve of the second central resistance portion 910-2, the partial curvature radius (e.g., RC1 = R7) near any one of the second terminal pair (terminal 82a, terminal 82b) can be greater than the curvature radius (e.g., RC2 = R2.5) of the folding portion closest to the second resistance portion 91-2.

[0096] As described above, the ceramic base 100 of the present invention can form a heating element pattern without a hairpin section in the central portion of the base plate 110 with a high embedding density of the heating element 114, thereby improving the temperature uniformity of the entire area of the upper surface of the base and significantly extending the life of the heating pattern.

[0097] As described above, in the present invention, specific matters such as specific constituent elements and limited embodiments and drawings are used for illustration, but this is only provided for a more comprehensive understanding of the present invention. The present invention is not limited to the described embodiments, and various modifications and variations can be made by those of ordinary skill in the technical 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 determined by the illustrated embodiments, and not only the appended claims, but all technical ideas equivalent or having equivalent variations to the claims should be interpreted as being included within the scope of the present invention.

Claims

1. A base, wherein: include: An insulating plate is provided with a heating element, and a shaft engaged at a lower portion of the insulating plate; The heating element includes a first heating element pattern, wherein the first heating element pattern includes a first resistor portion and a first connecting portion connected between a first terminal pair. When the first resistor portion is projected onto the plane of the insulating plate, the first resistor portion includes a first central resistor portion located in a region smaller than a diameter of a junction portion of the insulating plate and the shaft.

2. The base according to claim 1, wherein: The first resistor portion includes a plurality of arc portions extending along a circumferential direction and a plurality of folded portions for connecting the arc portions. The curved line of the first central resistor portion is formed so as to intersect an extended line of a virtual straight line passing through spaces separating adjacent folded portions.

3. The base according to claim 1, wherein: The first resistor unit includes: A plurality of arc portions extending along the circumferential direction, and A plurality of folding parts, used to connect the arc parts; The curved line of the first central resistor portion is formed so as to intersect with a virtual extension line extending from the folded portion most adjacent to the first central resistor portion.

4. The base according to claim 1, wherein: In the curve of the first central resistor portion, a curvature radius of a portion close to any one of the first terminal pair is larger than a curvature radius in a folded portion of the first resistor portion.

5. The base according to claim 4, wherein: A curvature radius of a portion close to any one of the first terminal pair is at least twice the maximum curvature radius of the folded portion of the first resistor portion.

6. The base according to claim 1, wherein: In the curve of the first central resistor portion, a portion close to any one of the first terminal pairs has a curvature radius greater than a curvature radius of the most adjacent folded portion among the folded portions of the first resistor portion.

7. The base according to claim 1, wherein: The first terminal pair is located in an area smaller than a diameter of a joining portion of the insulating plate and the shaft.

8. The base according to claim 1, wherein: The heating element includes a second heating element pattern, wherein the second heating element pattern includes a second resistor portion and a second connecting portion connected between the second terminal pair. When the first resistor portion and the second resistor portion are projected onto the plane of the insulating plate, the first resistor portion and the second resistor portion include a second central resistor portion located in a region smaller than a diameter of a junction portion between the insulating plate and the shaft.

9. The base according to claim 8, wherein: The second resistor unit includes: A plurality of arc portions extending along the circumferential direction, and A plurality of folding parts and arc parts for connecting; At least one of the curved line of the first central resistor portion and the curved line of the second central resistor portion is formed so as to intersect with an extension line of a virtual straight line passing through spaces separating adjacent folded portions.

10. The base according to claim 9, wherein: The adjacent folded portions include one of the folded portions of the first resistor portion and one of the folded portions of the second resistor portion that face each other.

11. The base according to claim 8, wherein: The second resistor section includes: A plurality of arc portions extending along the circumferential direction, and A plurality of folding parts, used to connect the arc parts; At least one of the curve of the first central resistor portion and the curve of the second central resistor portion is formed to intersect with a virtual extension line extending from a folded portion of the first central resistor portion that is most adjacent to the first central resistor portion or the second central resistor portion.

12. The base according to claim 8, wherein: The second resistor section includes: A plurality of arc portions extending along the circumferential direction, and A plurality of folding parts, used to connect the arc parts; At least one of the curve of the first central resistor portion and the curve of the second central resistor portion is formed to intersect with a virtual extension line extending from a folded portion of the second central resistor portion that is most adjacent to the first central resistor portion or the second central resistor portion.

13. The base according to claim 8, wherein: The second resistor section includes: A plurality of arc portions extending along the circumferential direction, and A plurality of folding parts, used to connect the arc parts; At least any one of the curves of the first central resistor portion and the curves of the second central resistor portion is formed in a manner that intersects with respective virtual extension lines extending from the folded portion of the first central resistor portion and the folded portion of the second central resistor portion that are respectively most adjacent to the first central resistor portion and the second central resistor portion.

14. The base according to claim 8, wherein: In the curve of the first central resistor portion and the curve of the second central resistor portion, the curvature radius of a portion close to any one of the terminal pairs is larger than the curvature radius of the folded portion of the first resistor portion and the second resistor portion, respectively.

15. The base according to claim 14, wherein: A curvature radius of a portion close to any one of the terminal pairs is at least twice the maximum curvature radius of the folded portions of the first resistor portion and the second resistor portion.

16. The base according to claim 8, wherein: In the curve of the first central resistor portion, a portion close to any one of the first terminal pairs has a curvature radius greater than a curvature radius of the most adjacent folded portion among the folded portions of the first resistor portion, In the curve of the second central resistor portion, a portion close to any one of the second terminal pair has a curvature radius greater than a curvature radius of the most adjacent folded portion among the folded portions of the second resistor portion.

17. The base according to claim 8, wherein: The second terminal pair is located in an area smaller than a diameter of a joining portion of the insulating plate and the shaft.

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