Substrate holding body

Abstract

To provide a substrate holding body capable of restraining positional deviation of a heat generating circuit in a heater.SOLUTION: A substrate holding body includes a plate having an upper surface on which a substrate is placed, a sheet-like heater arranged in parallel to the plate, and a fastening member for fastening the plate and the heater. The heater includes a first insulating sheet and a second insulating sheet, and a heat generating circuit interposed between the first insulating sheet and the second insulating sheet in a state where the heat generating circuit is bonded to neither the first insulating sheet nor the second insulating sheet. The heat generating circuit includes a main wiring portion extending in a direction along the outer peripheral edge of the heater, and an anchor wiring portion extending in a direction intersecting the direction in which the main wiring portion extends.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a substrate holder. [Background technology]

[0002] Patent Document 1 discloses a wafer heating device including a wafer holding plate having an upper surface on which a wafer is placed, and a heater for heating the wafer holding plate. The heater includes a base material made of an insulator, and a circuit pattern made of a resistance heating element. The insulator is an insulating resin. The resistance heating element is a metal that generates heat when electricity is passed through it. The heater has a structure in which a circuit pattern is sandwiched between two insulating sheets, for example. The circuit pattern is formed, for example, by etching a stainless steel foil. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-169005 Summary of the Invention [Problem to be solved by the invention]

[0004] The wafer heating device heats the wafer holding plate with a heater, thereby heating the wafer placed on the upper surface of the wafer holding plate. When the heater is in use, a current flows through the circuit pattern, causing the circuit pattern to heat up. As the temperature of the circuit pattern rises, the circuit pattern expands. If the circuit pattern is not bonded to an insulating sheet, the expansion of the circuit pattern due to the rise in temperature may cause the circuit pattern to shift in position relative to the insulating sheet. If the circuit pattern shifts in position, the temperature of the upper surface of the wafer holding plate may not be uniform.

[0005] An object of the present disclosure is to provide a substrate holder that can suppress misalignment of a heat generating circuit in a heater. [Means for solving the problem]

[0006] The substrate holder of the present disclosure comprises: a plate having an upper surface on which a substrate is placed; A sheet-shaped heater arranged parallel to the plate; a fastening member for fastening the plate and the heater, The heater is A first insulating sheet and a second insulating sheet; a heating circuit sandwiched between the first insulating sheet and the second insulating sheet in a state where the heating circuit is not attached to either the first insulating sheet or the second insulating sheet, The heating circuit includes: a main wiring portion extending in a direction along an outer periphery of the heater; and an anchor wiring portion extending in a direction intersecting the direction in which the main wiring portion extends. Effect of the Invention

[0007] The substrate holder of the present disclosure can suppress misalignment of the heat generating circuit in the heater. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view showing the configuration of a substrate holder according to the first embodiment. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing an enlarged cross section of a heater provided in the substrate holder according to the first embodiment. [Diagram 3] FIG. 3 is a schematic plan view of a heater provided in the substrate holder according to the first embodiment. [Figure 4] FIG. 4 is a schematic plan view showing an enlarged view of the portion surrounded by the dashed line in FIG. [Figure 5A] FIG. 5A is a schematic plan view showing an example of a modified example of the branch wiring. [Figure 5B] FIG. 5B is a schematic plan view showing another example of a modified branch wiring. [Figure 5C]FIG. 5C is a schematic plan view showing another example of a modified branch wiring. [Figure 5D] FIG. 5D is a schematic plan view showing another example of a modified branch wiring. [Figure 5E] FIG. 5E is a schematic plan view showing another example of a modified branch wiring. [Figure 5F] FIG. 5F is a schematic plan view showing another example of a modified branch wiring. [Figure 5G] FIG. 5G is a schematic plan view showing another example of a modified branch wiring. [Figure 6] FIG. 6 is a schematic plan view showing, in an enlarged scale, a main wiring portion constituting a heat generating circuit when the heater has a circular planar shape. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Description of the embodiments of the present disclosure] First, the embodiments of the present disclosure will be listed and described.

[0010] (1) The substrate holder of the present disclosure is a plate having an upper surface on which a substrate is placed; A sheet-shaped heater arranged parallel to the plate; a fastening member for fastening the plate and the heater, The heater is A first insulating sheet and a second insulating sheet; a heating circuit sandwiched between the first insulating sheet and the second insulating sheet in a state where the heating circuit is not attached to either the first insulating sheet or the second insulating sheet, The heating circuit includes: a main wiring portion extending in a direction along an outer periphery of the heater; and an anchor wiring portion extending in a direction intersecting the direction in which the main wiring portion extends.

[0011] The substrate holder of the present disclosure can suppress misalignment of the heat generating circuit in the heater. The reason that misalignment of the heat generating circuit can be suppressed is because the heat generating circuit has an anchor wiring portion, which will be described in detail later. Misalignment of the heat generating circuit occurs when the length along the extension direction of the main wiring portion increases due to expansion of the main wiring portion accompanying an increase in temperature. The anchor wiring portion suppresses movement of the main wiring portion in the extension direction of the main wiring portion and in a direction intersecting the extension direction of the main wiring portion. As a result of the anchor wiring portion suppressing movement of the main wiring portion, misalignment of the heat generating circuit is suppressed.

[0012] (2) In the substrate holder according to (1), The anchor wiring portion may be a branch wiring that branches off from the main wiring portion and through which no current flows.

[0013] According to the above configuration (2), the branch wiring branching from the main wiring portion is caught on the insulating sheet, so that movement of the main wiring portion can be suppressed.

[0014] (3) In the substrate holder according to (2), The branch wiring may have a first portion that is annular or C-shaped with a part of the annular shape missing.

[0015] When the first portion has a ring-shaped or C-shaped configuration, a part of the insulating sheet in contact with the first portion fits into the space surrounded by the ring-shaped or C-shaped configuration, which makes it easy to suppress movement of the main wiring portion. According to the above configuration (3), it is easy to obtain the effect of suppressing misalignment of the heat generating circuit.

[0016] (4) In the substrate holder of (3) above The branch wiring may have the first portion disposed away from the main wiring portion, and a second portion connecting between the main wiring portion and the first portion.

[0017] According to the above configuration (4), it is easy to prevent the positional deviation of the heating circuit.

[0018] (5) In the substrate holder according to (4), The second portion may have a width smaller than a width of the main wiring portion.

[0019] According to the above configuration (5), a part of the current flowing through the main wiring portion is unlikely to be diverted to the branch wiring through the second portion.

[0020] (6) In any one of the substrate holders (2) to (5), The fasteners are spaced apart along an outer periphery of the heater; The branch wiring may be disposed in a central portion between adjacent fastening members.

[0021] In the main wiring section, the portion close to the fastening member is clamped between the insulating sheets by the fastening member and is therefore less likely to move. A configuration in which the branch wiring is arranged in the center between adjacent fastening members can more effectively suppress movement of the main wiring section with a smaller number of branch wirings than a configuration in which the branch wiring is arranged in the portion close to the fastening member.

[0022] (7) In any one of the substrate holders (2) to (6), the heater has a polygonal shape when viewed from the top, the main wiring portion has a wiring portion that runs along a side that constitutes an outer periphery of the heater, The branch wiring may branch off from the wiring portion.

[0023] The wiring portion along the side that constitutes the outer periphery of the heater is linear. By providing the branch wiring to the linear wiring portion, it is easy to suppress the movement of the main wiring portion.

[0024] (8) In any one of the substrate holders (2) to (6), the heater has a circular shape when viewed from the top, the main wiring portion has a wiring portion along a circumference that constitutes an outer periphery of the heater, The branch wiring may branch off from the wiring portion.

[0025] The wiring portion along the circumference that constitutes the outer periphery of the heater is arc-shaped. By providing the branch wiring to the arc-shaped wiring portion, it is easy to suppress movement of the main wiring portion.

[0026] (9) In the substrate holder according to (1), The anchor wiring portion may be a meandering wiring that oscillates in a direction intersecting with a direction along an outer periphery of the heater. The meandering wiring is disposed between the main wiring portions and a current flows through the meandering wiring.

[0027] According to the above configuration (9), the meandering wiring arranged between the main wiring parts can expand and contract to absorb the movement of the main wiring parts, thereby making it possible to suppress the movement of the main wiring parts.

[0028] (10) In the substrate holder according to (9), the heater has a polygonal shape when viewed from the top, the main wiring portion has a first wiring portion and a second wiring portion respectively arranged along a first side and a second side that form corners of an outer periphery of the heater, The meandering wiring may be disposed at a corner portion connecting the first wiring portion and the second wiring portion.

[0029] According to the above (10), the meandering wiring arranged at the corner portion connecting the first wiring portion and the second wiring portion expands and contracts, whereby the movement of the main wiring portion can be suppressed.

[0030] (11) In the substrate holder according to (9) or (10), The meandering wiring may have a width smaller than a width of the main wiring portion.

[0031] According to the above configuration (11), the amount of heat generated in the meandering wiring is increased, and heat generation at the corners of the heater can be ensured.

[0032] [Details of the embodiment of the present disclosure] Hereinafter, specific examples of substrate holders and heaters provided on the substrate holders according to embodiments of the present disclosure will be described with reference to the drawings. The same reference numerals in the drawings indicate the same or corresponding parts. The drawings are schematic, and the dimensions of the members shown in the drawings do not necessarily correspond to the actual dimensions. However, the present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0033] <Substrate holder> The substrate holder of the embodiment is used, for example, in the manufacture of semiconductors. The substrate holder of this example is used, for example, in semiconductor inspection equipment. In semiconductor inspection, a test is performed to measure electrical performance while controlling the semiconductor substrate at a predetermined temperature. The substrate holder of the embodiment can also be used for purposes other than semiconductor inspection.

[0034] [Embodiment 1] The configuration of the substrate holder 1 of the first embodiment will be described with reference to FIG. 1. The substrate holder 1 includes a plate 2, a heater 3, and a fastening member 6. The plate 2 and the heater 3 are arranged on the substrate holder 1 in this order from the top. The substrate holder 1 is a device that heats the substrate 100 placed on the upper surface 20 of the plate 2 to a predetermined temperature by the heater 3. The substrate holder 1 is supported by a pedestal 7, which will be described later. Each component of the substrate holder 1 will be described in detail below. FIG. 1 is a schematic cross-sectional view of the substrate holder 1. In FIG. 1, in order to make the configuration of the substrate holder 1 easier to understand, a heat generating circuit 30 of the heater 3, which will be described later, is also shown, and the arrangement of the fastening member 6 and the support 71, which will be described later, is also shown.

[0035] (plate) 1, the plate 2 is a member on which the substrate 100 is placed. The plate 2 has an upper surface 20 on which the substrate 100 is placed. The plate 2 is heated by the heater 3, whereby the substrate 100 is heated.

[0036] The substrate 100 is, for example, a semiconductor substrate on which a plurality of semiconductors are formed. The shape of the substrate 100 is, for example, a disk shape or a rectangular plate shape. In other words, the planar shape of the substrate 100 viewed from above is a circle shape or a polygon shape. The substrate 100 in this example is a rectangular substrate in the shape of a rectangular plate. The planar shape of the substrate 100 is a quadrangle shape. The quadrangle shape is, for example, a square or a rectangle. The size of the substrate 100 is, for example, 200 mm or more and 400 mm or less on one side.

[0037] The shape of the plate 2 is, for example, a disk or a square plate. That is, the planar shape of the plate 2 when viewed from the top surface 20 is a circle or a polygon. The planar shape of the plate 2 is a shape that matches the planar shape of the substrate 100. The shape of the plate 2 in this example is a square plate. That is, the planar shape of the plate 2 is a square. The size of the plate 2 is slightly larger than that of the substrate 100. The size of the plate 2 is, for example, 210 mm or more and 410 mm or less on one side. For example, when the side of the substrate 100 is 300 mm, the side of the plate 2 is 310 mm. The size of the plate 2 is the dimension on a plane parallel to the top surface 20.

[0038] The thickness of the plate 2 is, for example, 5 mm or more and 25 mm or less, and preferably 7 mm or more and 15 mm or less. If the thickness of the plate 2 is 5 mm or more, it is easy to ensure the rigidity of the plate 2. If the thickness of the plate 2 is 25 mm or less, the heat generated by the heater 3 is easily transferred to the upper surface 20. The thickness of the plate 2 is the dimension along a direction perpendicular to the upper surface 20.

[0039] The plate 2 is made of a material having excellent thermal conductivity and high rigidity. The material of the plate 2 is, for example, a metal, a ceramic, or a ceramic composite. The metal constituting the plate 2 is, for example, copper, a copper alloy, aluminum, or an aluminum alloy. The ceramic constituting the plate 2 is, for example, silicon carbide, aluminum nitride, aluminum oxide, or silicon nitride. The ceramic composite constituting the plate 2 is, for example, a composite of silicon and silicon carbide, a composite of aluminum and silicon carbide, or a composite of aluminum, silicon, and silicon carbide. The above metals have high thermal conductivity. If the material of the plate 2 is the above metal, the plate 2 easily transmits heat. Therefore, the substrate 100 can be heated efficiently. The above ceramics or ceramic composite has higher rigidity than metal. If the material of the plate 2 is the above ceramics or ceramic composite, the plate 2 is less likely to deform. Therefore, the thickness of the plate 2 can be reduced. The material of the plate 2 in this example is a composite of silicon and silicon carbide (Si-SiC).

[0040] The thermal conductivity of the plate 2 is, for example, 100 W / m·K or more. The thermal conductivity of the plate 2 may further be 200 W / m·K or more, 300 W / m·K or more, or 400 W / m·K or more. This thermal conductivity is a value at 20°C. The thermal conductivity of copper is about 400 W / m·K, and the thermal conductivity of aluminum is about 230 W / m·K. The thermal conductivity of silicon carbide is about 200 W / m·K, the thermal conductivity of aluminum nitride is about 150 W / m·K, the thermal conductivity of aluminum oxide is about 30 W / m·K, the thermal conductivity of silicon nitride is about 30 W / m·K, and the thermal conductivity of Si-SiC is about 170 W / m·K.

[0041] The surface of the plate 2 may be subjected to a surface treatment. The surface treatment is, for example, plating. Specific examples of plating are nickel plating or nickel-phosphorus plating. The plating method is electrolytic plating or electroless plating.

[0042] Although not shown in this example, the plate 2 may be provided with a chuck mechanism that adsorbs the substrate 100 to the upper surface 20. By adsorbing the substrate 100 to the upper surface 20, warping of the substrate 100 is corrected. By adhering the entire substrate 100 to the upper surface 20, the entire substrate 100 is likely to be heated uniformly.

[0043] Furthermore, a temperature sensor (not shown) may be provided on the plate 2. This temperature sensor measures the temperature of the plate 2. The temperature of the heater 3 is controlled based on the temperature of the plate 2 measured by the temperature sensor.

[0044] Furthermore, the plate 2 may include a flow path for flowing a coolant inside the plate 2. The coolant flows through the flow path to cool the plate 2. After the substrate 100 is heated, the plate 2 is cooled, whereby the substrate 100 can be quickly cooled.

[0045] (heater) The heater 3 heats the plate 2. The heater 3 indirectly heats the substrate 100 placed on the upper surface 20 of the plate 2. The heater 3 is sheet-shaped. The planar shape of the heater 3 when viewed from above is circular or polygonal. The planar shape of the heater 3 is a shape that matches the planar shape of the plate 2. In this example, the planar shape of the heater 3 is rectangular. The size of the heater 3 is equal to the size of the plate 2.

[0046] As shown in FIG. 1, the heater 3 is arranged parallel to the plate 2. The heater 3 is fixed to the lower surface 21 of the plate 2 by a fastening member 6. The heater 3 in this example is held so as to be sandwiched between a first support plate 33a and a second support plate 33b. The first support plate 33a is arranged on the upper surface of the heater 3. The second support plate 33b is arranged on the lower surface of the heater 3. The first support plate 33a is not essential. The material of the first support plate 33a and the material of the second support plate 33b are, for example, metal, ceramics, or a composite of ceramics. The material of the first support plate 33a and the material of the second support plate 33b can be the same as those listed as the material of the plate 2, or stainless steel or Kovar. The material of the first support plate 33a and the material of the second support plate 33b may be the same or different. It is desirable that the difference between the thermal expansion coefficient of the plate 2 and the thermal expansion coefficient of the second support plate 33b is as small as possible. This makes it possible to suppress warping of the plate 2 caused by the difference between the thermal expansion coefficient of the plate 2 and the thermal expansion coefficient of the second support plate 33b. The difference between the thermal expansion coefficient of the plate 2 and the thermal expansion coefficient of the second support plate 33b is, for example, 10 ppm / °C or less, and preferably 5 ppm / °C or less.

[0047] As shown in Fig. 2, the heater 3 has a heating circuit 30, a first insulating sheet 32a, and a second insulating sheet 32b. The first insulating sheet 32a, the heating circuit 30, and the second insulating sheet 32b are laminated from the top of the heater 3 in this order. The heating circuit 30 is not bonded to either the first insulating sheet 32a or the second insulating sheet 32b, but is sandwiched between the first insulating sheet 32a and the second insulating sheet 32b. Fig. 2 is a schematic cross-sectional view of a portion of the heater 3.

[0048] <Heat generating circuit> The heating circuit 30 is formed by wiring 31 made of a resistive heating element. The resistive heating element is a material that generates heat when a current flows through it. The resistive heating element is, for example, a metal such as stainless steel or nickel-chromium steel. When a current flows through the heating circuit 30, the heating circuit 30 generates heat, and heat is generated from the heater 3. The heating circuit 30 in this example is formed by processing a metal foil into a predetermined shape. The processing of the metal foil is, for example, etching or laser processing. The heating circuit 30 in this example is processed from a stainless steel foil.

[0049] The thickness of the heating circuit 30, i.e., the thickness of the wiring 31, may be any thickness that provides an appropriate amount of heat when a current flows through the heating circuit 30. The thickness of the heating circuit 30 is, for example, 0.01 mm or more and 0.5 mm or less, and further 0.02 mm or more and 0.1 mm or less. The shape of the heating circuit 30, i.e., the width and arrangement of the wiring 31, is designed so that the temperature of the upper surface 20 is kept uniform when the plate 2 is heated by the heater 3. The detailed configuration of the heating circuit 30 will be described later.

[0050] <Insulation sheet> The first insulating sheet 32a and the second insulating sheet 32b electrically insulate the heat generating circuit 30 and mechanically protect the heat generating circuit 30. The first insulating sheet 32a and the second insulating sheet 32b are made of a material having both electrical insulation and heat resistance. The material of the first insulating sheet 32a and the material of the second insulating sheet 32b are, for example, resin or resin filled with filler. The resin constituting the first insulating sheet 32a and the second insulating sheet 32b is, for example, silicone resin or polyimide resin. The filler is a ceramic filler that has excellent thermal conductivity and also excellent electrical insulation. The material of the ceramic filler is, for example, boron nitride, aluminum nitride, aluminum oxide, or silicon oxide. An insulating sheet made of a resin filled with a filler can improve the thermal conductivity of the insulating sheet by the filler more than an insulating sheet made of a resin.

[0051] The material of the first insulating sheet 32a and the material of the second insulating sheet 32b may be the same or different. In this example, the material of the first insulating sheet 32a and the material of the second insulating sheet 32b are both silicone resin filled with filler.

[0052] When at least one of the first insulating sheet 32a and the second insulating sheet 32b is made of an elastic material, the insulating sheet is easily attached to the heat generating circuit 30. In the elastic insulating sheet, the surface in contact with the heat generating circuit 30 is elastically deformed. The surface of the insulating sheet in contact with the heat generating circuit 30 is recessed into the shape of the heat generating circuit 30, so that a part of the insulating sheet enters the gap of the heat generating circuit 30. That is, as shown in FIG. 2, at least a part of the wiring 31 is embedded in the insulating sheet. In particular, silicone resin has high elasticity. If the resin constituting the insulating sheet is silicone resin, the insulating sheet is easily elastically deformed. If the material of at least one of the first insulating sheet 32a and the second insulating sheet 32b is silicone resin or silicone resin filled with filler, the heat generating circuit 30 is easily embedded between the first insulating sheet 32a and the second insulating sheet 32b.

[0053] It is sufficient that at least a portion of the heat generating circuit 30 is embedded in at least one of the first insulating sheet 32a and the second insulating sheet 32b. The heat generating circuit 30 does not have to be completely embedded between the first insulating sheet 32a and the second insulating sheet 32b. In other words, as shown in Fig. 2, in the portions of the first insulating sheet 32a and the second insulating sheet 32b that are not in contact with the wiring 31, there may be a gap between the first insulating sheet 32a and the second insulating sheet 32b.

[0054] At least one of the first insulating sheet 32a and the second insulating sheet 32b has a Shore A hardness of, for example, 75 or more and 100 or less. If the Shore A hardness of the insulating sheet is within the above range, the insulating sheet is likely to be elastically deformed. If the Shore A hardness of at least one of the first insulating sheet 32a and the second insulating sheet 32b is within the above range, the heating circuit 30 is likely to be embedded between the first insulating sheet 32a and the second insulating sheet 32b. The Shore A hardness of the insulating sheet may further be 80 or more and 90 or less.

[0055] The thickness of each of the first insulating sheet 32a and the second insulating sheet 32b may be any thickness that can achieve insulation and protection of the heat generating circuit 30. The thickness of each of the first insulating sheet 32a and the second insulating sheet 32b is, for example, 0.1 mm or more and 3 mm or less, and further 0.3 mm or more and 1 mm or less. If the thickness of each of the first insulating sheet 32a and the second insulating sheet 32b is 0.1 mm or more, the heat generating circuit 30 is likely to be buried between the first insulating sheet 32a and the second insulating sheet 32b. If the thickness of each of the first insulating sheet 32a and the second insulating sheet 32b is 3 mm or less, and further 1 mm or less, the heater 3 can be made thin. The thickness of the first insulating sheet 32a and the thickness of the second insulating sheet 32b may be the same or different. The thickness of the first insulating sheet 32a may be, for example, 0.5 mm or less. If the first insulating sheet 32a is 0.5 mm or less, the heat generated by the heat generating circuit 30 is easily transferred. In this example, the first insulating sheet 32a has a thickness of 0.5 mm, and the second insulating sheet 32b has a thickness of 0.5 mm.

[0056] The ratio of the thickness of each of the first insulating sheet 32a and the second insulating sheet 32b to the thickness of the heating circuit 30 may be, for example, 2 or more and 60 or less, or further 6 or more and 20 or less. The thickness of each insulating sheet may be smaller than the thickness of the heating circuit 30. In other words, the thickness ratio may be less than 1. When the thickness of each insulating sheet is equal to or greater than the thickness of the heating circuit 30, that is, when the thickness ratio is 1 or more, the heating circuit 30 is likely to be embedded between the first insulating sheet 32a and the second insulating sheet 32b. In particular, when the thickness ratio is 2 or more, the heating circuit 30 is more likely to be embedded in the insulating sheets.

[0057] The size of each of the first insulating sheet 32a and the second insulating sheet 32b is slightly larger than that of the heat generating circuit 30. The heat generating circuit 30 is arranged so as not to protrude from the first insulating sheet 32a and the second insulating sheet 32b. The outer peripheral edges of each of the first insulating sheet 32a and the second insulating sheet 32b form the outer peripheral edge of the heater 3. The planar shape of each of the first insulating sheet 32a and the second insulating sheet 32b in this example is a square shape. The first insulating sheet 32a and the second insulating sheet 32b each have a through hole through which the fastening member 6 shown in FIG. 1 is inserted. In addition, the first insulating sheet 32a and the second insulating sheet 32b each have a through hole through which the support 71 shown in FIG. 1 is inserted. In this example, as shown in FIG. 3, the fastening members 6 are arranged at intervals along the outer peripheral edge of the heater 3. In addition, the support 71 is arranged at each of the four corners of the heater 3.

[0058] (Fastening members) The fastening member 6 fastens the plate 2 and the heater 3. As shown in FIG. 1, the fastening member 6 is inserted from below the heater 3 and is joined to the lower surface 21 of the plate 2. The fastening member 6 has a length that passes through the heater 3. The fastening member 6 is inserted into the gap in the heating circuit 30 and into the through holes formed in each of the first insulating sheet 32a and the second insulating sheet 32b. The heater 3 is fastened by the fastening member 6, so that the heating circuit 30 is held in a sandwiched state between the first insulating sheet 32a and the second insulating sheet 32b. The fastening member 6 in this example is a bolt.

[0059] <Details of the heating circuit> The detailed configuration of the heat generating circuit 30 will be described with reference to Figures 3 and 4. Figure 3 is a plan view of the heat generating circuit 30 of the heater 3 as seen from above, and is a schematic diagram of the entire heat generating circuit 30. Figure 4 is an enlarged view of the portion enclosed by the dashed square in Figure 3. The first insulating sheet 32a is not shown in Figures 3 and 4. The heat generating circuit 30 is hatched in Figures 3 and 4. Additionally, the fastening member 6 and the support 71 are each hatched in Figures 3 and 4. The shapes of the heating circuits 30 shown in FIGS. 3 and 4 are merely examples, and the invention is not limited to these.

[0060] As shown in FIG. 3, the heating circuit 30 has a pair of terminals 40. In this example, the pair of terminals 40 are arranged near the center of the heater 3. When the planar shape of the heater 3 is a square or a rectangle as in this example, the center of the heater 3 is the intersection of the diagonals. When the planar shape of the heater 3 is a circle, the center of the heater 3 is the center of the circle. The pair of terminals 40 are arranged symmetrically with respect to a center line C passing between the terminals 40. The heating circuit 30 has a shape symmetrical with respect to the center line C. A power line (not shown) is connected to each terminal 40. A power source (not shown) is connected to the power line.

[0061] (Main wiring section) The heat generating circuit 30 has a main wiring section 4 and an anchor wiring section 5. The main wiring section 4 is a section that extends in a direction along the outer periphery of the heater 3. The main wiring section 4 may extend generally parallel to the outer periphery of the heater 3, and the extending direction of the main wiring section 4 may not exactly coincide with the direction along the outer periphery of the heater 3. For example, the main wiring section 4 may be gently meandering or gently curved in the direction along the outer periphery of the heater 3. "Extending in a direction along the outer periphery of the heater 3" means that the smaller angle of the main wiring section 4 intersecting a line parallel to the outer periphery of the heater 3 is less than 45°. In this example, five main wiring sections 4 are arranged at intervals from the center of the heater 3 to the outer periphery. Adjacent main wiring sections 4 are connected to each other. The main wiring section 4 connects the terminals 40 in a single stroke. The main wiring part 4 closest to the center of the heater 3 is connected to a terminal 40. When a voltage is applied between the terminals 40, a current flows through the main wiring part 4. The flow of current causes the main wiring part 4 to generate heat. The main wiring part 4 expands with an increase in temperature, and the length of the main wiring part 4 along the extension direction increases.

[0062] The outer periphery of the heater 3 in this example is a quadrangle formed of four corners 35 and four sides 36 connecting adjacent corners 35. The sides 36 include a pair of first sides 36a parallel to each other and a pair of second sides 36b perpendicular to the first sides 36a and parallel to each other. The corners 35 are formed by the first sides 36a and the second sides 36b. The main wiring portion 4 in this example has a wiring portion 41 along the sides 36 constituting the outer periphery of the heater 3. The wiring portion 41 is linear. In Figs. 3 and 4, the linear wiring portion 41 is shown for the sake of simplicity of the drawings, but the wiring portion 41 may be gently meandering. The wiring portion 41 includes a first wiring portion 41a and a second wiring portion 41b arranged along the first side 36a and the second side 36b, respectively. The longer the wiring portion 41, the greater the increase in length due to temperature rise.

[0063] (Anchor wiring section) The anchor wiring portion 5 is a portion that extends in a direction intersecting the extension direction of the main wiring portion 4. "Extending in an intersecting direction" means that the smaller angle of the anchor wiring portion 5 intersecting the extension direction of the main wiring portion 4 is 45° or more. The anchor wiring portion 5 suppresses the displacement of the heat generating circuit 30 with respect to the first insulating sheet 32a and the second insulating sheet 32b shown in FIG. 2. The anchor wiring portion 5 mainly suppresses the movement of the main wiring portion 4 in the extension direction of the main wiring portion 4 and in the direction intersecting the extension direction of the main wiring portion 4. The displacement of the heat generating circuit 30 occurs when the length of the main wiring portion 4 increases due to the expansion of the main wiring portion 4 caused by the temperature rise. The longer the wiring portion 41 is, the more likely the displacement of the heat generating circuit 30 occurs. In particular, the position of the heat generating circuit 30 is easily displaced so that the middle part of the wiring portion 41 approaches the side 36.

[0064] The anchor wiring portion 5 may be in the form of a branch wiring 51 branching off from the main wiring portion 4, or in the form of a meandering wiring 55 disposed between the main wiring portions 4. In the following, the branch wiring 51 will be described first.

[0065] <Branch wiring> No current flows through the branch wiring 51 branching off from the main wiring section 4 because it has the same potential as the main wiring section 4. Since no current flows through the branch wiring 51, the branch wiring 51 does not generate heat.

[0066] The mechanism by which the branch wiring 51 suppresses misalignment of the heat generating circuit 30 is as follows. When the branch wiring 51 is embedded between the first insulating sheet 32a and the second insulating sheet 32b shown in Fig. 2, the branch wiring 51 gets caught on the insulating sheet, and movement in the direction in which the main wiring portion 4 extends and in the direction in which it intersects with the main wiring portion 4 is suppressed. Furthermore, when the branch wiring 51 comes into contact with the insulating sheet, friction between the branch wiring 51 and the insulating sheet suppresses movement of the main wiring portion 4. As a result, misalignment of the heat generating circuit 30 is suppressed.

[0067] The branch wiring 51 branches off from the wiring portion 41. In this example, in the main wiring portion 4 arranged on the outermost periphery, the branch wiring 51 is provided in each of the first wiring portion 41a and the second wiring portion 41b. In addition, in the main wiring portions 4 arranged second and third from the outermost periphery, the branch wiring 51 is provided in the first wiring portion 41a.

[0068] A specific example of the shape of the branch wiring 51 will be described with reference to FIG. 4. The branch wiring 51 may have a first portion 511 that is ring-shaped or C-shaped with a portion of the ring missing. The ring shape includes a circular ring or a polygonal ring. The circular ring shape includes an elliptical ring. The polygonal ring shape includes a triangular ring, a square ring, a hexagonal ring, and the like. The branch wiring 51a and the branch wiring 51b shown in FIG. 4 have only the first portion 511. In the branch wiring 51a and the branch wiring 51b, the first portion 511 branches directly from the wiring portion 41. The first portion 511 of the branch wiring 51a is C-shaped with a portion of the ring missing. The first portion 511 of the branch wiring 51b is ring-shaped.

[0069] The branch wiring 51 may have a first portion 511 and a second portion 512, as in the branch wiring 51c shown in FIG. 4. In this embodiment, the first portion 511 is disposed away from the main wiring portion 4. The second portion 512 connects between the main wiring portion 4 and the first portion 511. In the branch wiring 51c, the second portion 512 branches off from the wiring portion 41, and the first portion 511 is connected to the tip of the second portion 512. The first portion 511 of the branch wiring 51c is C-shaped with a portion of the annular shape missing.

[0070] 4, the branch wiring 51 may have a continuous linear pattern 513 extending in an intersecting direction from the main wiring portion 4. The linear pattern 513 of the branch wiring 51d is formed by one continuous line.

[0071] The shape of the second portion 512 may be straight, curved, or a combination of straight and curved shapes. The width of the second portion 512 may be smaller than the width of the main wiring portion 4. The branch wiring 51 is a portion that does not need to generate heat. By making the width of the second portion 512 smaller than the width of the main wiring portion 4, a part of the current flowing through the main wiring portion 4 is less likely to be diverted to the branch wiring 51 through the second portion 512.

[0072] When the first portion 511 is annular or C-shaped, a part of the insulating sheet in contact with the first portion 511 enters the space surrounded by the annular or C-shaped shape, thereby restricting movement of the main wiring portion 4. The branch wiring 51 having the first portion 511 has more catches on the insulating sheet, making it easier to suppress movement of the main wiring portion 4. The branch wiring 51 having the first portion 511 is more likely to suppress misalignment of the heat generating circuit 30 than the branch wiring 51 that is a linear pattern 513.

[0073] A modified example of the branch wiring 51 having only the first portion 511 will be described. The shape of the first portion 511 is not limited to a C-shape with a part of a circular ring missing, but may be a C-shape with a part of a polygonal ring missing. For example, as shown in FIG. 5A, the shape of the first portion 511 may be a C-shape with a part of a square ring missing. As shown in FIG. 5B, the shape of the first portion 511 may be a C-shape with a part of a triangular ring missing. Although not shown in this example, the shape of the first portion 511 is not limited to a circular ring, but may be a polygonal ring such as a triangular ring or a square ring.

[0074] A modified example of the branch wiring 51 having the first portion 511 and the second portion 512 will be described. When the first portion 511 has a C-shape, it may be a C-shape with a part of a rectangular loop missing as shown in Fig. 5C, or a C-shape with a part of a triangular loop missing as shown in Fig. 5D. When the first portion 511 has a ring shape, it may be a circular ring shape as shown in Fig. 5E, or a square ring shape as shown in Fig. 5F.

[0075] A modified example of the branch wiring 51 having a linear pattern 513 will be described. The linear pattern 513 of the branch wiring 51d shown in FIG. 4 is J-shaped having a straight portion branching from the wiring portion 41 and a curved portion extending from the tip of the straight portion. The shape of the linear pattern 513 may be, for example, an I-shape formed by a single straight line, or a zigzag shape. Furthermore, for example, as shown in FIG. 5G, the shape of the linear pattern 513 may be T-shaped having a straight portion branching from the wiring portion 41 and a straight portion intersecting the straight portion.

[0076] The shape, arrangement, number, etc. of the branch wiring 51 can be changed arbitrarily. For example, the number of branch wirings 51 may be set according to the length of the wiring portion 41. The branch wiring 51 may be provided in the long wiring portion 41, and may not be provided in the short wiring portion 41. As shown in FIG. 3, the branch wiring 51 may be arranged in the center between adjacent fastening members 6. In the main wiring portion 4, the portion close to the fastening member 6 is easily clamped between the first insulating sheet 32a and the second insulating sheet 32b shown in FIG. 2. Therefore, the portion close to the fastening member 6 is difficult to move. If the branch wiring 51 is arranged in the center between the adjacent fastening members 6, the movement of the main wiring portion 4 can be effectively suppressed by a small number of branch wirings 51. In other words, the number of branch wirings 51 can be reduced. The portion close to the fastening member 6 is, for example, a portion located within a range of less than 10 mm from the fastening member 6. In other words, the branch wiring 51 may be arranged at a position 10 mm or more away from the fastening member 6.

[0077] In the main wiring portion 4, heat is likely to escape through the fastening member 6 in the portion close to the fastening member 6. As shown in Fig. 3, by making the width of the portion close to the fastening member 6 smaller than the width of the portion far from the fastening member 6, the amount of heat generated in that portion is increased, thereby compensating for the heat escaping from the fastening member 6. This ensures that heat is generated in the portion close to the fastening member 6.

[0078] When the heater 3 has a circular planar shape, the main wiring portion 4 has a wiring portion 41 that follows the circumference that constitutes the outer periphery of the heater 3. In this case, the branch wiring 51 is provided so as to branch off from the arc-shaped wiring portion 41, as shown in FIG.

[0079] Serpentine wiring The meandering wiring 55 is disposed between the main wiring portions 4. "Disposed between the main wiring portions 4" means that the meandering wiring 55 is disposed in a section midway through the main wiring portion 4, and the main wiring portion 4 is connected in series with the meandering wiring 55 sandwiched between them. In other words, the meandering wiring 55 can be said to be a part of the main wiring portion 4. Since a current flows through the meandering wiring 55, the meandering wiring 55 generates heat. In this example, the meandering wiring 55 is disposed in a corner portion connecting the first wiring portion 41a and the second wiring portion 41b in the main wiring portion 4 disposed on the outermost periphery.

[0080] The meandering wiring 55 has a shape that oscillates in a direction along the outer periphery of the heater 3 and in a direction intersecting the outer periphery of the heater 3. The meandering wiring 55 has a plurality of bent portions. In this example, the meandering wiring 55 has four bent portions.

[0081] The mechanism by which the meandering wiring 55 suppresses misalignment of the heat generating circuit 30 is as follows. Even if the length of each of the first wiring portion 41a and the second wiring portion 41b increases due to expansion accompanying a rise in temperature of the main wiring portion 4, the movement of the main wiring portion 4 can be absorbed by the expansion and contraction of the meandering wiring 55. As a result, the movement of the main wiring portion 4 is suppressed, and the misalignment of the heat generating circuit 30 is suppressed. The greater the number of bends, the easier it is to absorb the movement of the main wiring portion 4. If the number of bends is 3 or more, the effect of suppressing misalignment of the heat generating circuit 30 is easily obtained. The upper limit of the number of bends is, for example, 10. The number of bends may be, for example, 3 to 10, or 4 to 8.

[0082] The width of the meandering wiring 55 may be smaller than the width of the main wiring portion 4, i.e., the width of each of the first wiring portion 41a and the second wiring portion 41b. In this example, as shown in FIG. 3, a support 71 is disposed near a corner connecting the first wiring portion 41a and the second wiring portion 41b in the main wiring portion 4 disposed on the outermost periphery. Heat generated at this corner is likely to escape along the support 71. By making the width of the meandering wiring 55 smaller than the widths of the first wiring portion 41a and the second wiring portion 41b, the amount of heat generated in the meandering wiring 55 is increased, and heat generation at the corner can be ensured.

[0083] The amount of heat generated in that portion can be increased not only by reducing the width of the main wiring portion 4 in the heat generating circuit 30, but also by increasing the wiring density of the main wiring portion 4. The width of the main wiring portion 4 and the wiring density of the main wiring portion 4 can be set appropriately according to the design of the heat generating circuit 30.

[0084] (pedestal) 1, the base 7 is a member that supports the substrate holder 1. The material of the base 7 is, for example, metal, ceramics, or a composite of ceramics. The material of the base 7 may be any of those listed as the material of the plate 2. The material of the base 7 in this example is aluminum oxide (Al2O3).

[0085] The base 7 in this example has a support pillar 71 extending upward from the upper surface of the base 7. The support pillar 71 supports the substrate holder 1 so that a space is formed between the substrate holder 1 and the base 7. The support pillar 71 in this example has a length that penetrates the heater 3 and reaches from the upper surface of the base 7 to the lower surface of the plate 2. The support pillar 71 is cylindrical. The support pillar 71 is fixed to the base 7 by a bolt 72. The bolt 72 is inserted from below the base 7 and is connected to the lower surface 21 of the plate 2. [Explanation of symbols]

[0086] 1 Board holder 2 Plate 20 Top side 21 Bottom side 3 Heater 30 Heating Circuit 31 Wiring 32a First insulating sheet 32b Second insulating sheet 33a First support plate 33b Second support plate 35 angles 36 sides 36a first side, 36b second side 4 Main wiring section 40 Terminals 41 Wiring section 41a first wiring section, 41b second wiring section 5 Anchor Wiring Section 51 Branch wiring 51a, 51b, 51c, 51d Branch wiring 511 First part 512 Second part 513 Linear Pattern 55 Serpentine Wiring 6 Fastening members 7 Pedestal 71 Pillar 72 Volts 100 Substrates C center line

Claims

1. a plate having an upper surface on which a substrate is placed; A sheet-shaped heater arranged parallel to the plate; a fastening member for fastening the plate and the heater, The heater is A first insulating sheet and a second insulating sheet; a heating circuit sandwiched between the first insulating sheet and the second insulating sheet in a state where the heating circuit is not attached to either the first insulating sheet or the second insulating sheet, The heating circuit includes: a main wiring portion extending in a direction along an outer periphery of the heater; and an anchor wiring portion extending in a direction intersecting with a direction in which the main wiring portion extends. Substrate holder.

2. 2. The substrate holder according to claim 1, wherein the anchor wiring portion is a branch wiring that branches off from the main wiring portion and through which no current flows.

3. The substrate holder according to claim 2 , wherein the branch wiring has a first portion that is annular or C-shaped with a portion of the annular portion missing.

4. 4. The substrate holder of claim 3, wherein the branch wiring has the first portion disposed away from the main wiring portion, and a second portion connecting between the main wiring portion and the first portion.

5. The substrate holder of claim 4 , wherein the second portion has a width smaller than a width of the main wiring portion.

6. The fasteners are spaced apart along an outer periphery of the heater; 4. The substrate holder according to claim 2, wherein the branch wiring is disposed in a central portion between adjacent fastening members.

7. the heater has a polygonal shape when viewed from the top, the main wiring portion has a wiring portion that runs along a side that constitutes an outer periphery of the heater, 4. The substrate holder according to claim 2, wherein the branch wiring branches off from the wiring portion.

8. the heater has a circular shape when viewed from the top, the main wiring portion has a wiring portion along a circumference that constitutes an outer periphery of the heater, 4. The substrate holder according to claim 2, wherein the branch wiring branches off from the wiring portion.

9. the anchor wiring portion is a meandering wiring that oscillates in a direction intersecting with a direction along an outer circumferential edge of the heater, 2. The substrate holder of claim 1, wherein the meandering wiring is disposed between the main wiring portions and a current flows through the meandering wiring.

10. the heater has a polygonal shape when viewed from the top, the main wiring portion has a first wiring portion and a second wiring portion respectively arranged along a first side and a second side that form corners of an outer periphery of the heater, The substrate holder of claim 9 , wherein the meandering wiring is disposed at a corner portion connecting the first wiring portion and the second wiring portion.

11. 11. The substrate holder according to claim 9, wherein a width of the meandering wiring is smaller than a width of the main wiring portion.

Images