Ceramic heater

Abstract

This ceramic heater comprises: a plate-like heating element; and a heater base having a base body for holding the heating element. The base body has: a heating element holding surface which is in contact with the rear surface of the heating element; and a flow passage formation part which forms, between the rear surface of the heating element and the flow passage formation part, a flow passage for allowing a cooling medium fed from the outside to circulate therethrough. The flow passage formation part has: an inflow port into which the cooling medium flows from the outside of the base body; and an outflow port which is formed away from the inflow port in a first intersecting direction intersecting with the thickness direction and which connects the flow passage and the outside of the base body. The length of the flow passage extending from the inflow port to the outflow port in the first intersecting direction is at least 1 / 2 of the external dimension of the heating element in the first intersecting direction.

Description

Ceramic heater

[0001] This invention relates to a ceramic heater. This application claims priority based on Japanese Patent Application No. 2025-011402, filed in Japan on January 27, 2025, the contents of which are incorporated herein by reference.

[0002] In recent years, development aimed at further increasing integration, such as 2.5D (2.5-dimensional) and 3D (3-dimensional) mounting, has been accelerating, particularly in the fields of smartphones, mobile phones, and tablet devices. For mounting to obtain SoCs (System-on-a-Chip) such as memory and application processors, reflow soldering, which heat-treats multiple devices in a continuous manner, has become the mainstream method. In reflow soldering, for example, mounting components are attached to bumps (protruding electrodes) formed from solder paste on a substrate such as a chip, and the solder is melted in a reflow oven to perform soldering. However, reflow soldering has limitations in miniaturizing bumps and narrowing the gaps between bumps, making further high integration difficult. Therefore, as an alternative technology to reflow soldering, a mounting method called thermocompression bonding has attracted attention and is being put into practical use in some areas.

[0003] Thermocompression bonding is a method of mounting chips by applying a load to each chip using a heater equipped with a heating element, followed by cooling. It is known that using a ceramic heating element in the heater used in thermocompression bonding suppresses deformation of the heating element when a load is applied, enabling high-precision mounting. For this reason, it is expected that thermocompression bonding using ceramic heaters with ceramic heating elements will become the mainstream mounting method in the future.

[0004] Patent Document 1 describes a ceramic heater that uses silicon carbide as the heating element. In this ceramic heater, an insulating coating made of borosilicate glass or aluminosilicate glass is provided on the surface of the heating element made of silicon carbide.

[0005] Patent No. 3710690

[0006] Incidentally, when performing a thermocompression bonding method using the ceramic heater described above, the chip is sometimes heated while a load is applied, and then cooled in that state. In this case, in order to improve production efficiency, it is necessary to cool the ceramic heater quickly.

[0007] One of the objectives of this invention is to provide a ceramic heater that can perform cooling rapidly.

[0008] The present invention encompasses the following [1] to [8]. It is also preferable to combine two or more of the following inventions as needed. [1] A ceramic heater comprising: a plate-shaped heating element having a surface facing one side in the thickness direction and a back surface facing the other side in the thickness direction; and a heater base having a base body that holds the heating element from the other side in the thickness direction, wherein the base body has a heating element holding surface facing one side in the thickness direction and in contact with the back surface of the heating element; and a flow path forming portion recessed from the heating element holding surface to the other side in the thickness direction, forming a flow path between it and the back surface of the heating element through which a cooling medium supplied from the outside can flow, wherein the flow path forming portion has an inlet through which the cooling medium flows from the outside of the base body into the flow path, and an outlet formed away from the inlet in a first intersecting direction intersecting the thickness direction, and communicating the flow path with the outside of the base body, and the length of the flow path extending from the inlet to the outlet in the first intersecting direction is 1 / 2 or more of the external dimensions of the heating element in the first intersecting direction. [2] The flow path forming portion has a first wall-like portion that extends along the outer peripheral edge of the base body and in the intersecting first direction, and the tip surface of the first wall-like portion forms at least a part of the heating element holding surface, as described in [1]. [3] The flow path forming portion has a second wall-like portion that extends from the end of the first wall-like portion on the side closer to the inlet, along the outer peripheral edge of the base body and in an intersecting second direction that intersects both the thickness direction and the intersecting first direction, and the tip surface of the second wall-like portion forms at least a part of the heating element holding surface, as described in [2]. [4] The ceramic heater according to any one of [1] to [3], wherein the base body is rectangular when viewed in the thickness direction, and there are two inlets and two outlets, the inlets are formed at two diagonally opposite corners of the four corners of the base body, and the outlets are formed at two other corners of the four corners of the base body adjacent to the two corners where the inlets are formed.[5] The ceramic heater according to any one of [1] to [4], wherein the flow path forming portion has a third wall-like portion extending in a direction intersecting the direction in which the flow path extends, between the inlet and the outlet, and the tip surface of the third wall-like portion forms at least a part of the heating element holding surface. [6] The ceramic heater according to any one of [1] to [5], wherein the back surface of the heating element, in a portion that overlaps with the flow path when viewed from the thickness direction, is provided with at least one of a convex portion projecting in the thickness direction and a concave portion recessed in the thickness direction. [7] The ceramic heater according to [6], wherein the convex portion and the concave portion extend in a direction intersecting the direction in which the flow path extends. [8] The ceramic heater according to any one of [1] to [7], wherein the heating element is formed using silicon carbide. [9] A ceramic heater according to any one of [1] to [8], wherein the base body has a heating element fixing portion that rises from the bottom surface of the flow path forming portion in the center, and the tip surface of the heating element fixing portion forms at least a part of the heating element holding surface.

[10] A ceramic heater according to any one of [1] to [9], wherein the heating element is made of a silicon carbide sintered body having an insulating coating on its surface, and the base body is made of insulating ceramics.

[11] A ceramic heater according to any one of [1] to

[10] , wherein the heating element and the base body are rectangular and have the same shape when viewed from the thickness direction, the external dimensions of the heating element are the length of one side of the heating element when viewed from one side in the thickness direction, and the outer peripheral edge of the base body consists of four sides exposed to the outside of the base body.

[12] The ceramic heater according to any one of [1] to

[11] , wherein the inlet and outlet are formed at adjacent corners of the base body, the outer surfaces of the first wall-like portion and the second wall-like portion of the flow path forming portion are exposed to the outside of the base body, and the inner surfaces form part of the flow path, and the second wall-like portion further has a third wall-like portion extending in the intersecting first direction from the end of the second wall-like portion furthest from the inlet, the length of the second wall-like portion in the intersecting second direction is shorter than the length of the first wall-like portion in the intersecting first direction, and the length of the third wall-like portion is longer than the length of the third wall-like portion in the intersecting first direction.

[13] The ceramic heater according to any one of [1] to

[12] , wherein the inlet is formed on the bottom surface of the flow channel forming portion, and the outlet is formed surrounded by the bottom surface of the flow channel forming portion, the back surface of the heating element, the first wall-like portion, and the third wall-like portion.

[0009] According to one aspect of the present invention, a ceramic heater capable of rapid cooling is provided.

[0010] Figure 1 is a schematic diagram of a preferred example of the ceramic heater of this embodiment, viewed from a second intersecting direction. Figure 2 is a schematic diagram of a preferred example of the ceramic heater of this embodiment, with the heat transfer plate removed, viewed from one side in the thickness direction. Figure 3 is a schematic cross-sectional view of a preferred example of the heating element of the ceramic heater of this embodiment, viewed from a second intersecting direction. Figure 4 is a schematic diagram of a preferred example of the heating element of this embodiment, viewed from one side in the thickness direction. Figure 5 is a schematic perspective view of a preferred example of the heater base of the ceramic heater of this embodiment, viewed from one side in the thickness direction. Figure 6 is a schematic diagram of a preferred example of the heater base of this embodiment, viewed from one side in the thickness direction. Figure 7 is a schematic perspective view of the heater base of the ceramic heater of this embodiment, viewed from the other side in the thickness direction. Figure 8 is a schematic perspective view showing the manufacturing state using a flip-chip bonder with the ceramic heater of this embodiment.

[0011] Hereinafter, preferred examples of each embodiment of the ceramic heater of the present invention will be described with reference to the drawings. In all the following drawings, the dimensions and proportions of each component may be shown differently as appropriate for the sake of clarity. Furthermore, these embodiments are described in detail to better understand the spirit of the invention and do not limit the present invention unless otherwise specified. For example, unless otherwise specified, conditions such as material, quantity, type, number, size, shape, position, and proportion may be changed, added, or omitted as necessary.

[0012] [Ceramic Heater] The ceramic heater of this embodiment includes at least a heating element and a heater base. Preferably, a heat transfer plate and a connection plate are further included as needed. In the following description, the direction perpendicular to the main surface of the plate-shaped heating element included in the ceramic heater may be referred to as the thickness direction. In the ceramic heater, the side where the heating element is provided may be referred to as one side in the thickness direction, and the opposite side may be referred to as the other side in the thickness direction. Also, the direction parallel to the main surface of the heating element may be referred to as the first intersecting direction or the second intersecting direction. The first intersecting direction and the second intersecting direction are perpendicular to each other. The first intersecting direction and the second intersecting direction may be perpendicular (orthogonal) to the thickness direction of the heating element or the base body. In the following description, as needed, "intersecting" may mean "orthogonal". For the sake of easy explanation, in the following description, one side in the thickness direction may be called the downward direction, the other side in the thickness direction may be called the upward direction, the first intersecting direction may be called the X direction, and the second intersecting direction may be called the Y direction. Fig. 1 is a view of the ceramic heater of this embodiment as seen from the second intersecting direction. Fig. 2 is a view of the ceramic heater of this embodiment in a state where the heat transfer plate 30 is removed, as seen from one side in the thickness direction, for example, from the downward side. As shown in Figs. 1 and 2, the ceramic heater 100 of this embodiment includes a plate-shaped heating element 1, a heater base 21, and a connection plate 22. More specifically, in the ceramic heater 100 of Fig. 1, the heat transfer plate 30, the heating element 1, the heater base 21, and the connection plate 22 overlap in this order. In the following description using the drawings of this embodiment, the thickness direction of the plate-shaped heating element 1 is referred to as the thickness direction or the thickness direction Dt. Also, one direction intersecting (orthogonal) to the thickness direction Dt is referred to as the first intersecting direction or the first intersecting direction Da. The direction intersecting (orthogonal) to both the thickness direction Dt and the first intersecting direction Da is referred to as the second intersecting direction or the second intersecting direction Db.

[0013] [Heating Element] Figure 3 is a cross-sectional view of a plate-shaped heating element included in the ceramic heater of this embodiment. As shown in Figures 1 and 3, the plate-shaped heating element 1 has a surface 1a (first main surface) facing one side in the thickness direction Dt, for example, downward, and a back surface 1b (second main surface) facing the other side in the thickness direction Dt. As shown in Figure 2, the heating element 1 in this embodiment is rectangular or substantially rectangular when viewed from the thickness direction Dt. As shown in Figure 3, the heating element 1 may also be rectangular when viewed in cross-section. The size and shape of the heating element 1 can be arbitrarily selected. As a specific example, the outer shape of the heating element 1 may be a thin plate with sides of 22 mm and a thickness of 1 mm.

[0014] As shown in Figure 3, the heating element 1 preferably has a central portion 1A and a film 1B formed on its surface. Specifically, the heating element 1 preferably has a thin plate-shaped silicon carbide sintered body 1A and an insulating film 1B formed on the surface of the silicon carbide sintered body.

[0015] (Silicon carbide sintered body) The silicon carbide sintered body 1A of the heating element 1 preferably contains silicon carbide, more preferably consists only of silicon carbide, and has a sintered body density of 2.5 g / cm³. ３ It is even more preferable that the silicon carbide is as described above, and even more preferably that the sintered body density is 2.8 g / cm³. ３ It consists of the silicon carbide described above, and is particularly preferably a sintered body density of 3.15 / cm³. ３ It consists of the silicon carbide described above. The sintered density of silicon carbide sintered body 1A is 2.5 g / cm³. ３ By doing so, sufficient bonding force between silicon carbide particles can be obtained. Furthermore, the sintered body density of silicon carbide sintered body 1A is 2.5 g / cm³. ３ By doing so, sufficient mechanical strength at high temperatures can be ensured. Therefore, damage to the heating element 1 due to the load during bonding and plastic deformation at high temperatures can be suppressed, and excellent surface accuracy of several micrometers can be easily obtained.

[0016] The theoretical density of silicon carbide is 3.21 g / cm³. ３ Therefore, the sintered body density of silicon carbide sintered body 1A in this embodiment is 2.5 g / cm³. ３ 3.21g / cm or more ３The following are preferred.

[0017] The silicon carbide sintered body 1A preferably has a thermal conductivity at room temperature of 100 W / m·K or more, more preferably 140 W / m·K or more, and even more preferably 180 W / m·K or more. As described above, the sintered body density of the silicon carbide sintered body 1A is 2.5 g / cm ３ or more and is dense. Also, since the silicon carbide sintered body 1A can be sintered without adding a sintering aid as described later, there are few impurities present at the grain boundaries, and a fine and uniform structure can be obtained. Due to these factors, the silicon carbide sintered body 1A can have a high thermal conductivity of 100 W / m·K or more. This silicon carbide sintered body 1A has excellent heat uniformity, has no poor connection at the bonding part, and has a high product yield. Furthermore, the time required for cooling is short, the time for one bonding process is shortened, and the cost performance is high, and it does not break due to thermal shock even during rapid temperature rise or rapid temperature drop. The thermal conductivity of the silicon carbide sintered body 1A at room temperature is preferably as high as possible, but is usually 260 W / m·K or less.

[0018] The electrical resistivity (electrical resistance rate) of the silicon carbide sintered body 1A at room temperature (25°C) is preferably 0.1 Ω·cm or more and 100 Ω·cm or less, more preferably 0.15 Ω·cm or more and 85.0 Ω·cm or less, even more preferably 0.2 Ω·cm or more and 70.0 Ω·cm or less, still more preferably 3.0 Ω·cm or more and 65.0 Ω·cm or less, and particularly preferably 10.0 Ω·cm or more and 60.0 Ω·cm or less. It may also be 20.0 Ω·cm or more and 50.0 Ω·cm or less, 30.0 Ω·cm or more and 40.0 Ω·cm or less, etc.

[0019] By setting the electrical resistivity of the silicon carbide sintered body 1A to 0.1 Ω·cm or higher, it is possible to suppress the flow of large currents through the silicon carbide sintered body 1A. Therefore, it is possible to suppress the stress caused by electromagnetic induction in the lead wires 24 of the electrode 20 described later, thereby suppressing the decrease in the positional accuracy of the heater head. In addition, by setting the electrical resistivity of the silicon carbide sintered body 1A to 0.1 Ω·cm or higher, it becomes possible to sufficiently secure the resistance value of the silicon carbide sintered body 1A without thinning the heating element 1, and the bonding pressure (normally 50 kg / cm²) can be reduced. ２ It can be made strong enough to withstand (a certain degree).

[0020] Furthermore, by setting the electrical resistivity of the silicon carbide sintered body 1A to 100 Ω·cm or less, current can be passed without applying a large voltage, and since no special power supply is required, it is preferable.

[0021] (Insulating Coating) The insulating coating 1B of the heating element 1 is preferably provided on at least the surface 1a of the silicon carbide sintered body 1A. The insulating coating 1B is made of a material described later. As shown in Figure 3, it is preferable that the insulating coating 1B is formed not only on the surface 1a but also on the back surface 1b and the sides of the heating element 1. In other words, the insulating coating 1B may be formed on all surfaces of the heating element 1.

[0022] The thickness of the insulating film 1B can be arbitrarily selected, but it is preferable to have a thickness of 10 μm or more and 100 μm or less. Preferably, the thickness of the insulating film 1B is 20 μm or more and 80 μm or less, and more preferably 30 μm or more and 70 μm or less. The upper and lower limits of the range for the thickness of the insulating film 1B can be arbitrarily combined. If the thickness of the insulating film 1B is less than 10 μm, the insulating properties of the heating element 1 (heater) may be significantly reduced, and if it exceeds 100 μm, the insulating film 1B may easily peel off from the silicon carbide sintered body 1A due to internal strain of the heating element 1, which is undesirable. If the thickness of the insulating film 1B is 10 μm or more, the insulating properties as a heater can be ensured. Furthermore, by making the insulating film 1B 100 μm or less, the heat capacity of the insulating film 1B can be reduced, and the thermal conductivity from the silicon carbide sintered body 1A to the object via the insulating film 1B can be increased, thereby increasing the response speed of the heater.

[0023] The insulating coating 1B has an electrical resistance of 10 at room temperature. ９ Preferably it is Ω or more, 10 １０ It is more preferable that the resistance be Ω or greater. This ensures insulation between the heating element 1 and the chip, which is the object to be heated by the heating element 1. The electrical resistance of the insulating coating 1B at room temperature can be measured using an insulation resistance meter, specifically by applying a high voltage between the glass surface coated on the heater and the heater electrode.

[0024] To suppress damage caused by differences in thermal expansion, it is preferable that the thermal expansion coefficient of the insulating coating 1B is close to that of the silicon carbide sintered body 1A. The thermal expansion coefficient of the silicon carbide sintered body 1A is approximately 3.7 × 10⁻⁶ from 50°C to 350°C. －６ The coefficient of thermal expansion of insulating film 1B from 50°C to 350°C is 2 × 10⁻⁶. －６ / K or more 6×10 －６ It is preferable that the value is less than or equal to / K, and 2.6 × 10 －６ / K or more 5.0×10 －６ It is more preferable that it be less than or equal to / K, and 3.2 × 10 －６ / K or more 4.2×10 －６ It is even more preferable that the temperature is less than or equal to / K. The heating element 1 undergoes rapid temperature increases and decreases many times. For this reason, the thermal expansion coefficient of the insulating coating 1B is set to the thermal expansion coefficient of the silicon carbide sintered body 1A in the base portion of the heating element 1 (approximately 3.7 × 10⁻¹⁰ from 50°C to 350°C). －６ By bringing the temperature closer to / K, the peeling of the insulating coating 1B from the silicon carbide sintered body 1A can be suppressed. The thermal expansion coefficient of the insulating coating 1B is measured by a thermal expander. As a thermal expander, for example, a horizontal total expansion type thermal expander (model number DIL402SU, manufactured by NETZSCH) can be used.

[0025] The insulating coating 1B can be selected arbitrarily, but SiO ２ And, Al ２ O ３ and B ２ O ３ It is preferable that the insulating film 1B includes a matrix consisting of one or both of the following: ２ and Al ２ O ３It may also include a matrix consisting of SiO ２ and B ２ O ３ It may also include a matrix consisting of SiO ２ and Al ２ O ３ and B ２ O ３ It may also include a matrix consisting of and .

[0026] The insulating film 1B, by including the matrix described above, can ensure sufficient insulation with the aforementioned electrical resistance. Note that "the insulating film 1B includes the above substance as a matrix" means that the substance indicated as the matrix is ​​included as the main component in the insulating film 1B. "Main component" may mean that its amount is greater than that of the other components. The matrix is ​​preferably 30.0% to 98.0% by mass, more preferably 38.0% to 70.0% by mass, and even more preferably 46.0% to 57.0% by mass, based on the total mass of the insulating film 1B. If necessary, it may also be 40.0% to 85.0% by mass, or 52.0% to 65.0% by mass, etc.

[0027] The insulating coating 1B is SiO ２ Preferably, the insulating coating 1B contains 30.0% by mass or more and less than 93.0% by mass, more preferably 30.0% by mass or more and 70.0% by mass or less, and even more preferably 30.0% by mass or more and 50.0% by mass or less. If necessary, it may also be 40.0% by mass or more and 85.0% by mass or 55.0% by mass or more and 65.0% by mass or less. SiO in insulating coating 1B ２ A content of 30.0% by mass or more and less than 93.0% by mass allows for the creation of a stable glass network structure, enabling it to function as a matrix.

[0028] Insulating coating 1B is Al ２ O ３ If it contains Al ２ O ３It is preferable that the total mass of the insulating film 1B contains 20.0% by mass or more, more preferably 22.0% by mass or more, more preferably 25.0% by mass or more, and even more preferably 30.0% by mass or more. ２ O ３ The content of is preferably 50.0% by mass or less, and more preferably 45.0% by mass or less. ２ O ３ If it contains Al in insulating film 1B, ２ O ３ The presence of a content of 20.0% by mass or more results in thermal stability and excellent mechanical properties.

[0029] Insulating coating 1B is B ２ O ３ If it contains, the insulating coating 1B is B ２ O ３ It is preferable that the total mass of the insulating coating 1B contains 2.0% by mass or more, more preferably 5.0% by mass or more, and even more preferably 10.0% by mass or more. ２ O ３ The content of is preferably 20.0% by mass or less. ２ O ３ When it contains [the specified element], it forms an insulating coating with excellent chemical durability.

[0030] Also, Al ２ O ３ The amount is B ２ O ３ It is preferable that the amount be greater than [a certain amount].

[0031] The insulating film 1B preferably contains at least one component selected from the group consisting of zinc oxide, gallium oxide, magnesium oxide, and tin oxide as a further addition to the matrix. In particular, the component added to the matrix preferably contains zinc oxide. Furthermore, the component added to the matrix preferably contains both zinc oxide and magnesium oxide.

[0032] The total content of the additional components mentioned above is preferably more than 5.0% by mass and 30.0% by mass or less, relative to the total mass of the insulating film 1B. When the content of the above components is within the above range, crystallization of the insulating film 1B is suppressed, and it is thought that the film is less likely to crack even during long-term use. In addition, since the thermal expansion coefficient of the insulating film 1B approaches that of SiC, it is thought to have excellent long-term stability.

[0033] The content of the above-mentioned added components is preferably 5.0% by mass or more and 30.0% by mass or less, more preferably 8.0% by mass or more and 25.0% by mass or less, and even more preferably 10.0% by mass or more and 20.0% by mass or less, based on the total mass of the insulating film 1B. If necessary, it may also be 5.0% by mass or more and 15.0% by mass or less, 6.0% by mass or more and 13.0% by mass or less, or 7.0% by mass or more and 10.0% by mass or less, etc.

[0034] When the above component is zinc oxide, the zinc oxide content is preferably 5.0% by mass or more and 10.0% by mass or less based on the total mass of the insulating film 1B.

[0035] When magnesium oxide is included as one of the above components, the magnesium oxide content is preferably 5.0% by mass or more and 10.0% by mass or less based on the total mass of the insulating film 1B. The insulating film 1B containing magnesium oxide tends to be less prone to cracking even when heat is applied. It is thought that the structure of the insulating film is stabilized by the inclusion of magnesium oxide (Mg atoms) in the insulating film 1B.

[0036] When gallium oxide is included as one of the above components, the gallium oxide content is preferably 5.0% by mass or more and 10.0% by mass or less based on the total mass of the insulating film 1B.

[0037] When the above component includes tin oxide, the tin oxide content is preferably 5.0% by mass or more and 10.0% by mass or less based on the total mass of the insulating film 1B.

[0038] On the other hand, it is preferable that the insulating film 1B contains as little sodium (Na), calcium (Ca), and barium (Ba) as possible. That is, it is preferable that these elements are not present at all, or if they are present, only in very trace amounts. For example, it is preferable that the Na content in the insulating film 1B is below the detection limit in elemental analysis by ICP emission spectrometry. For example, in the elemental analysis employed in this embodiment, the detection limits for each of the following elements are as follows: B: 20 ​​ppm, Al: 5 ppm, Zn: 5 ppm, Mg: 5 ppm, Ca: 5 ppm, Ba: 10 ppm, Na: 200 ppm

[0039] The Na content in insulating film 1B is preferably less than 200 ppm. It is more preferably less than 50 ppm or less than 5 ppm. It is even more preferably below the detection limit in elemental analysis. The Ca content in insulating film 1B is preferably less than 5 ppm. It is even more preferably below the detection limit in elemental analysis.

[0040] The Ba content in the insulating coating 1B is preferably less than 5 ppm. It is even more preferable that it is below the detection limit in elemental analysis.

[0041] Furthermore, the "Na content" mentioned above may refer to the NaO content calculated by assuming that all the Na contained in the insulating coating was Na oxide (NaO), based on the Na content obtained by elemental analysis of the insulating coating. The same applies to the Ca and Ba components.

[0042] The Na and Ca contained in the insulating coating can move within the film in an ionic state when heated, potentially reducing the stability of the insulating coating and causing cracks. Furthermore, the elution of the moving Na and Ca onto the surface of the insulating coating could contaminate semiconductor chips processed by the thermocompression bonding method. Additionally, the Ba contained in the insulating coating increases the mobility of Na and Ca ions. Therefore, by keeping the Na, Ca, and Ba content in insulating coating 1B below 5 ppm each, crack formation can be suppressed even when heat is applied.

[0043] (Intermediate layer) The heating element 1 may have an intermediate layer (not shown) at the interface between the silicon carbide sintered body 1A and the insulating film 1B. The intermediate layer may be an oxide film formed on the surface of the silicon carbide sintered body 1A. The oxide film can be formed on the surface of the silicon carbide sintered body 1A that forms the insulating film 1B by ozone treatment, corona discharge treatment, etc. Alternatively, SiO can be formed on the surface of the silicon carbide sintered body 1A by physical vapor deposition (PVD) or chemical vapor deposition (CVD). ２ A film may be formed and used as an intermediate layer.

[0044] To give yet another example, a primer layer using a silane coupling agent or the like may be formed on the surface of the silicon carbide sintered body 1A, and this may be used as an intermediate layer.

[0045] As a silane coupling agent, it is preferable to select one that adheres well to the insulating film that is later formed. For example, as a silane coupling agent, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2-(Amm Noethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanatetopropyltriethoxysilane, etc. can be used.

[0046] The silane coupling agent may be applied directly (without dilution) to the surface of the silicon carbide sintered body 1A, or it may be used after being appropriately diluted with an organic solvent such as alcohol. Furthermore, a silane coupling agent to which a small amount of water and acid have been added to partially accelerate hydrolysis may also be used.

[0047] A single silane coupling agent may be used, or two or more may be used in combination.

[0048] The intermediate layer facilitates the wetting and spreading of the insulating film 1B material when forming the insulating film 1B on the surface of the silicon carbide sintered body 1A. This makes the formation of the insulating film 1B easier.

[0049] The thickness of the intermediate layer can be arbitrarily selected, but for example, 0.2 μm to 2 μm is preferred, and 0.5 μm to 1.5 μm is more preferred.

[0050] In the above, the example given for the heating element 1 mainly uses silicon carbide as its constituent material, but its specific composition can be changed as appropriate. Furthermore, the heating element 1 is not limited to one using silicon carbide, as long as it is a ceramic material, it may also mainly use alumina.

[0051] Figure 4 is a view of the heating element 1 of this embodiment, seen from one side in the thickness direction, for example, from below. That is, it shows the surface of the heating element 1 on the heat transfer plate 30 side. The surface of the heating element 1 is rectangular or substantially rectangular in shape, for example, a square or quadrilateral. As shown in Figure 4, the heating element 1 has four sides 1c, 1d, 1e, and 1f that form the outer edge of the heating element 1. The heating element 1 has slits that are generally parallel to each other and extend inward from two opposing sides. More specifically, in the intersecting second direction Db, for example in the Y direction, two slits 2 and 3 are formed on the two opposing sides 1c and 1e, cut from those opposing sides toward the opposite side. The heating element 1 has a substantially S-shape due to these slits. The heating element 1 may also have an inverted substantially S-shape. The two slits 2 and 3 are generally parallel to each other. These slits are generally parallel to the remaining two sides 1d and 1f that are opposite each other in the first intersecting direction Da, for example in the X direction, among the sides 1c, 1d, 1e, and 1f. The lengths of slits 2 and 3 in the second intersecting direction Db can be arbitrarily selected and are, for example, about 2 / 3 to 3 / 4 of the length of sides 1d and 1f (L2). If necessary, they may be 6 / 10 to 9 / 10 or 7 / 10 to 8 / 10, etc. However, they are not limited to these examples.

[0052] Due to these slits 2 and 3, the heating element 1 has three plate-like portions 1p, 1q, and 1r. As shown in Figure 4, the plate-like portions 1p, 1q, and 1r are connected and each extends in the second intersecting direction Db. Plate-like portion 1p is formed on one side of the first intersecting direction Da relative to the slit 2, for example, on one side in the X direction, and extends in the second intersecting direction Db. Plate-like portion 1q is formed between the slit 2 and the slit 3 and extends in the second intersecting direction Db. One end of plate-like portion 1q in the second intersecting direction Db is connected to plate-like portion 1p, and the other end is connected to plate-like portion 1r. Plate-like portion 1r is formed on the other side of the first intersecting direction Da relative to the slit 3 and extends in the second intersecting direction Db. Plate-like portion 1r is connected to the other end of plate-like portion 1q in the second intersecting direction Db.

[0053] Slits 2 and 3 absorb the effects of thermal expansion and contraction of the heating element 1 due to temperature changes. Therefore, by providing slits 2 and 3, it is possible to make the heating element 1 more resistant to thermal stress. Consequently, it becomes possible to form the heating element 1 with a thinner plate thickness, and as a result the heat capacity of the heating element 1 is reduced, enabling rapid heating and cooling. In addition, by making the heating element 1 roughly S-shaped with slits 2 and 3, the current flows through a roughly S-shaped path, improving the uniformity of heating of the heating element 1.

[0054] As shown in Figures 2 and 4, the heating element 1 is preferably provided with through holes 4 and 5 for mounting electrodes 20 used to energize the heating element 1, a through hole 6 for forming a gas passage for adsorbing the chip, which is the object to be heated, through holes 7 and 8 and grooves 9 and 10 for forming a gas passage for adsorbing the heat transfer plate 30, and through holes 13 and 14 for inserting countersunk screws 15 and 15 for fixing the heating element 1 to the heater base 21. The shape, number, position and size of these may be arbitrarily selected as needed.

[0055] The through holes 4 and 5 for electrode mounting are located at two diagonally opposite corners, i.e., at the respective ends of the plate-shaped portions 1p and 1r of the heating element 1 (i.e., the starting and ending points of the S-shaped heating element 1). The through hole 6 is located approximately in the center of the heating element 1. In other words, the through hole 6 is located approximately midway along the straight line connecting the through holes 4 and 5. The grooves 9 and 10 are located at two other diagonally opposite corners, recessed from the surface 1a of the heating element 1 on the other side in the thickness direction Dt, for example, the upper side, and are formed in an approximately L-shape along the outer edge of the heating element 1 when viewed in the thickness direction Dt. The through holes 7 and 8 are provided inside the grooves 9 and 10, respectively, and the grooves 9 and 10 communicate with the through holes 7 and 8, respectively. The through holes 13 and 14 for fixing the heating element 1 to the heater base 21 are arranged with the through hole 6 in between, and are equally far from the through hole 6.

[0056] As shown in Figure 2, a pair of electrodes 20 are connected to the heating element 1. In the heating element 1, the electrodes 20 are connected to through holes 4 and 5 located at both ends (also called the starting and ending points) of the substantially S-shaped structure. The pair of electrodes 20, 20 are energized through the heating element 1. Each electrode 20 has a lead wire 24 and a bolt 16 for fixing the lead wire 24 to the heating element 1. The bolt 16 is inserted through the through holes 4 and 5 located at the respective ends of the substantially S-shaped structure of the heating element 1 to fix the lead wire 24 to the heating element 1. Note that the electrodes 20 fixed to the heating element 1 are not limited to this example, and it is preferable that they be arranged so that the current flows more uniformly over the entire surface of the heating element 1, depending on the shape of the heating element 1.

[0057] The heating element 1 is preferably one with a small heat capacity in order to rapidly raise and lower its temperature. Therefore, in order to reduce the heat capacity while maintaining the mechanical strength of the heating element 1, the thickness of the heating element 1 is preferably about 0.5 to 1.5 mm, more preferably 0.7 to 1.3 mm, and even more preferably 0.8 to 1.2 mm. The length of one side of the heating element 1 as viewed from the thickness direction can be arbitrarily selected, but examples include 10 to 20 mm, 20 to 30 mm, or 30 to 40 mm. The length of the side may also be 15 to 25 mm or 25 to 35 mm.

[0058] On the back surface 1b of the heating element 1 (the surface facing the heater base 21), protrusions 17 projecting in the thickness direction Dt and recesses 18 recessed in the thickness direction Dt are provided at arbitrarily selected positions. In the example shown in the figure, when viewed from the thickness direction Dt, protrusions 17 projecting from the back surface 1b in the thickness direction Dt are provided in the portion that overlaps with the flow paths 212r1 and 212r3 of the heater base 21 (see Figure 6), which will be described later. Also, on the back surface 1b of the heating element 1, when viewed from the thickness direction Dt, multiple recesses 18 recessed in the thickness direction Dt are provided in the portion that overlaps with the flow paths 212r2 and 212r4 of the heater base 21 (see Figure 6), which will be described later. The protrusions 17 are arranged on the plate-like portion 1q of the heating element 1, and the recesses 18 are arranged on the plate-like portions 1p and 1r. The number, shape, and position of the protrusions 17 and recesses 18 can be arbitrarily selected as needed. In this embodiment, the protrusion 17 is rib-shaped and extends in the intersecting second direction Db, for example, the Y direction. That is, in a plan view, the protrusion 17 extends in a direction intersecting the flow path 212r1, described later, which proceeds from the inlet 213A to the outlet 214A, and the flow path 212r3, described later, which proceeds from the inlet 213B to the outlet 214B (see Figure 6). The width and height of the protrusion may be constant, but are not limited to that. The protrusion may or may not have a surface that contacts the bottom surface of the flow path of the base body 210. On the other hand, in this embodiment, the recess 18 is groove-shaped and extends in the intersecting first direction Da, for example, the X direction. That is, in a plan view, the recess 18 extends in a direction intersecting the flow path 212r2, described later, which proceeds from the inlet 213A to the outlet 214B, and the flow path 212r4, described later, which proceeds from the inlet 213B to the outlet 214A (see Figure 6). The width and depth of the recess may be constant, but are not limited to that. The protrusion 17 may have a pin-shaped or other protrusion that projects from the back surface 1b in the thickness direction Dt. Similarly, the recess 18 may be a round hole recessed in the thickness direction Dt relative to the back surface 1b. The protrusion 17 and recess 18 are provided to ensure a large surface area of ​​the heating element 1 exposed in the flow path 212r connecting the inlet 213A and outlet 214A, which will be described later.

[0059] [Heat Transfer Plate] As shown in Figure 1, a plate-shaped heat transfer plate 30 is provided on the surface 1a of the heating element 1. In this embodiment, the heat transfer plate 30 is attracted and installed by the negative pressure generated in grooves 9 and 10 provided in the heating element 1. The outer shape of the plate-shaped heat transfer plate 30 in plan view may be the same as or approximately the same as the outer shape of the heating element 1. The heat transfer plate 30 is used to uniformly transfer the heat from the heating element 1 to the object. Therefore, the heat transfer plate 30 must have excellent heat conductivity, heat resistance, and thermal shock resistance. The material forming the heat transfer plate 30 can be arbitrarily selected, but it is preferable to use a ceramic such as aluminum nitride (AlN). The thickness of the heat transfer plate 30 may be arbitrarily selected as needed, or the thickness of the heat transfer plate 30 may be constant.

[0060] [Heater Base] The heater base 21 holds the heating element 1 from the other side in the thickness direction Dt, for example, from above. The heater base 21 is located between the connecting plate 22 (described later) and the heating element 1. The heater base 21 and the heating element 1 can be fixed by a method selected as needed, but as described above, they can be fixed using screws. The heater base 21 preferably has a base body 210 for holding the heating element 1 and legs 230 used for fixing to the connecting plate 22.

[0061] The heater base 21 is made of an insulating ceramic with high thermal insulation properties and excellent thermal shock resistance. While any ceramic can be selected for the heater base 21, silicon nitride (Si) is preferred. ３ N ４ ), calcium silicate (CaO・SiO ２ Examples include ), and Sialon.

[0062] The heater base 21 holds the heating element 1 from the other side in the thickness direction Dt, for example, from above. Therefore, the heater base 21 can suppress heat loss to the other side in the thickness direction Dt when the heating element 1 is heated up. In other words, the heater base 21 holds the heating element 1 while insulating the heat from the heating element 1. This makes it possible to rapidly heat up the heating element 1 with a small input power. In addition, since heat loss to the connecting plate 22 to which the heater base 21 is attached is reduced, displacement of the heater due to thermal expansion of the connecting plate 22 can be suppressed. Furthermore, since the heater base 21 mechanically reinforces the heating element 1 from one direction, damage to the heating element 1 due to the load during bonding can be suppressed.

[0063] Figure 5 is a perspective view of the heater base 21 of the ceramic heater 100 of this embodiment, viewed from one side in the thickness direction, for example, from below. Figure 6 is a view of the heater base 21 of this embodiment, viewed from one side in the thickness direction. Figure 7 is a perspective view of the heater base of the ceramic heater of this embodiment, viewed from the other side in the thickness direction, for example, from above. As shown in Figures 5 to 7, the heater base 21 integrally comprises a base body 210 that holds the heating element 1 and a pair of legs 230.

[0064] As shown in Figures 5 and 6, the base body 210 has the same external shape and size as the heating element 1 when viewed from the thickness direction Dt. That is, the base body 210 is formed in a rectangular shape when viewed from the thickness direction Dt. The base body 210 has a predetermined thickness that can be arbitrarily selected in the thickness direction Dt.

[0065] The base body 210 has a heating element holding surface 211 and a flow path forming portion (flow path) 212. As shown in Figure 1, the heating element holding surface 211 faces one side in the thickness direction Dt and contacts the back surface 1b of the heating element 1.

[0066] As shown in Figures 5 and 6, the channel forming portion 212 is recessed from the heating element holding surface 211 on the other side in the thickness direction Dt, for example, upward. The channel forming portion 212 is formed away from the heating element holding surface 211 on the other side in the thickness direction Dt and has a bottom surface 212b facing one side in the thickness direction Dt. The channel forming portion 212 forms a channel 212r through which a cooling medium supplied from the outside can flow.

[0067] The base body 210 of the ceramic heater 100 has a first wall-like portion 216, a second wall-like portion 217, a third wall-like portion 218, and a heating element fixing portion 219 formed thereon. The first wall-like portion 216, the second wall-like portion 217, and the third wall-like portion 218 are continuous and connected in this order. The outer surfaces (outer surfaces) of the first wall-like portion and the second wall-like portion are exposed to the outside of the base body, and their inner surfaces (inner surfaces) form part of the flow path. Both sides of the third wall-like portion 218 form part of the flow path. Preferably, the distance (depth) from the bottom surface 212b of the first wall-like portion 216, the second wall-like portion 217, the third wall-like portion 218, and the heating element fixing portion 219 is the same. The corners and edges of the ceramic heater 100, such as the first wall-like portion 216, the second wall-like portion 217, the third wall-like portion 218, and the heating element fixing portion 219, may be chamfered or have curved surfaces as needed.

[0068] The first wall-like portion 216 is provided along each of the two sides 210p and 210r that face each other in the second intersecting direction Db, out of the four sides 210p, 210q, 210r, and 210s that form the outer periphery of the base body 210 in a plan view. In other words, in this embodiment, two first wall-like portions 216 extend in the first intersecting direction Da along each of the sides 210p and 210r of the base body 210. The first wall-like portion 216 extends along the entire length of each of the sides 210p and 210r. The first wall-like portion 216 rises from the bottom surface 212b to one side in the thickness direction Dt, and its tip surface forms at least a part of the heating element holding surface 211. Sides 210p and 210r each form a part (one side) of the heating element holding surface of the first wall-like portion 216, and sides 210p and 210r, and sides 210q and 210s are parallel to each other. As shown in Figure 2, the first wall-like portion 216 is in contact with the back surface 1b of the heating element 1 at its outer peripheral edge along sides 1c and 1e of the heating element 1. Note that the outer peripheral edge of the base body may refer to the four sides of the base body having the four sides that are exposed to the outside, or the tip surfaces (part of the heating element holding surface) of the first wall-like portion 216 or the second wall-like portion 217.

[0069] In this specification, the tip surface of the first wall-like portion 216 refers to the surface of the first wall-like portion 216 that faces in the thickness direction. The same applies to the tip surfaces of the second wall-like portion 217 and the third wall-like portion 218, which will be described later.

[0070] As shown in Figures 5 and 6, the second wall-like portion 217 is provided along two opposing sides 210q and 210s of the four sides 210p, 210q, 210r, and 210s that form the outer periphery of the base body 210, in the intersecting first direction Da. In this embodiment, the second wall-like portion 217 extends from the end of the first wall-like portion 216 closest to the inlets 213A and 213B described later, along the sides 210q and 210s of the base body 210, in the intersecting second direction Db. Sides 210q and 210s each form a part of the two second wall-like portions 217. The length of the second wall-like portion 217 can be arbitrarily selected, but in this example, it extends over a length of about 2 / 3 to 3 / 4 of the total length of sides 210q and 210s. The length of the second wall-like portion 217 may be 6 / 10 to 9 / 10 or 7 / 10 to 8 / 10 of the total length of the sides 210q and 210s. The second wall-like portion 217 rises from the bottom surface 212b on one side in the thickness direction Dt, and its tip surface forms at least a part of the heating element holding surface 211. As shown in Figure 2, the second wall-like portion 217 is in contact with the back surface 1b of the heating element 1 at the outer peripheral edge along the sides 1d and 1f of the heating element 1.

[0071] As shown in Figures 5 and 6, the third wall-like portion 218 extends inward from the end of the second wall-like portion 217 on the side closer to the outlets 214A and 214B (described later), along the intersecting first direction Da, into the base body 210. The third wall-like portion 218 rises from the bottom surface 212b on one side in the thickness direction Dt, and its tip surface forms at least a part of the heating element holding surface 211. As shown in Figure 2, the third wall-like portion 218 contacts the back surface 1b of the heating element 1 at the plate-like portions 1p and 1r of the heating element 1. In other words, the third wall-like portion 218 holds the plate-like portions 1p and 1r of the heating element 1 from one side in the thickness direction Dt. The length of the third wall-like portion 218 can be arbitrarily selected, for example, it may be 1 / 10 to 4 / 10 or 2 / 10 to 3 / 10 of the total length of the sides 210p and 210r. The length of the second wall-like portion 217 in the second intersecting direction is preferably shorter than the length of the first wall-like portion 216 in the first intersecting direction, and preferably longer than the length of the third wall-like portion 218 in the first intersecting direction. The direction in which the third wall-like portion 218 extends may be perpendicular to the direction in which the slits 2 and 3 of the heating element 1 extend.

[0072] As shown in Figures 5 and 6, the heating element fixing portion 219 is formed in the center of the base body 210 when viewed from the thickness direction Dt. The heating element fixing portion 219 protrudes from the bottom surface 212b of the flow path forming portion 212 to one side in the thickness direction Dt. The tip surface of the heating element fixing portion 219 forms at least a part of the heating element holding surface 211. The shape of the heating element fixing portion 219 is preferably symmetrical in plan view. For example, the heating element fixing portion 219 may have a central wall portion of an arbitrarily selected shape, and the central wall portion may be oval or a rounded rectangle, and the central wall portion may extend parallel to the second wall-like portion 217. The length of the central wall portion can be arbitrarily selected, for example, it may be 2 / 10 to 9 / 10 or 4 / 10 to 7 / 10 of the length of the second wall-like portion 217. The central wall portion may have two wall-like sections extending parallel to each other and in opposite directions, and the two wall-like sections may be parallel to the third wall-like section 218. The lengths of the two wall-like sections can be arbitrarily selected, but for example, they may be 1 / 20 to 4 / 10 or 1 / 10 to 3 / 10 of the length of the first wall-like section 216.

[0073] The heating element fixing portion 219 has a through hole 231 that communicates with the through hole 6 of the heating element 1 which forms a gas passage and penetrates the base body 210 in the thickness direction Dt, and female screw holes 233 and 234 that communicate with the through holes 13 and 14 of the heating element 1. As shown in Figure 2, the heating element 1 is fixed to the heater base 21 by fastening countersunk screws 15, 15 through the through holes 13 and 14 of the heating element 1 to the female screw holes 233 and 234 of the heating element fixing portion 219 of the base body 210.

[0074] Furthermore, the heating element fixing portion 219 has thermocouple holding recesses 236 and 237 for holding thermocouples (not shown) that are in contact with the heater (heating element) to measure temperature, and through holes 236h and 237h for inserting the wiring of the thermocouples. As shown in Figure 7, grooves 236m and 237m are formed on the back surface of the bottom surface 212b of the base body 210, communicating with the through holes 236h and 237h. The wiring of the thermocouples is housed in the grooves 236m and 237m.

[0075] As shown in Figures 2, 5, and 6, the flow path forming section 212, between its bottom surface 212b and the back surface 1b of the heating element 1, forms a flow path 212r through which a cooling medium for cooling the heating element 1 flows, using a first wall-like section 216, a second wall-like section 217, and a third wall-like section 218.

[0076] The flow path forming section 212 has inlets 213A and 213B through which the cooling medium flows into the flow path from the outside, and outlets 214A and 214B through which the cooling medium flows out of the flow path 212r to the outside. The inlets and outlets are formed at adjacent corners of the base body, respectively. The number of inlets and outlets can be arbitrarily selected from one or more numbers, and in this embodiment there are two of each.

[0077] As shown in Figures 5 to 7, in this embodiment, the inlets 213A and 213B are formed on the bottom surfaces of two diagonally positioned corners 210a and 210c of the four corners 210a, 210b, 210c, and 210d of the base body 210. The shape of the inlets can be arbitrarily selected, but in this example, they are circular or substantially circular in plan view. The inlets 213A and 213B penetrate the base body 210 in the thickness direction Dt and open to one side in the thickness direction Dt on the bottom surface 212b.

[0078] As shown in Figures 2, 5, and 6, the outlets 214A and 214B are formed at the two other corners 210b and 210d of the base body 210, which are adjacent to the two corners 210a and 210c where the inlets 213A and 213B are formed. The outlets 214A and 214B are each formed surrounded by the bottom surface 212b of the flow path forming section 212, the back surface 1b of the heating element 1, the first wall-like section 216, and the third wall-like section 218. The outlets open between these in the intersecting first direction Da, for example in the X direction, and communicate the inside of the flow path 212r with the outside of the base body 210. The outlets 214A and 214B can allow the cooling refrigerant to flow out in the intersecting first direction Da. The shape of the outlets 214A and 214B is, for example, a rectangle when viewed from the intersecting first direction Da. The cooling medium discharged from the outlets 214A and 214B may be recovered, or it may simply flow out to the outside. The width of the outlets 214A and 214B, for example the width in the intersecting second direction Db, can be arbitrarily selected and may be 1 / 2, 1 / 3, 1 / 4, 1 / 5, or 1 / 6 of the external dimensions L1 of the heating element 1 (length of one side of the heating element 1).

[0079] Furthermore, the base body 210 has through holes 221 and 222 formed on the bottom surfaces of two corners 210b and 210d where outlets 214A and 214B are formed, which communicate with the through holes 4 and 5 of the heating element 1. As shown in Figure 7, on the back surface of the base body 210, which faces the other side in the thickness direction Dt, for example, upward, recesses 226 and 227 are formed in the portion corresponding to the through holes 221 and 222 of the base body 210, which are recessed from the back surface of the bottom surface 212b to one side in the thickness direction Dt, for example, downward. The through holes 221 and 222 and the recesses 226 and 227 communicate with each other. The through holes 221 and 222 penetrate the base body 210 in the thickness direction Dt in the portion where the recesses 226 and 227 are formed.

[0080] As shown in Figure 1, in this embodiment, the through holes 221 and 222 have an inner diameter larger than the outer diameter of the nuts 225 that are fastened to bolts 16 inserted through the through holes 4 and 5 for fixing the lead wires 24 (see Figure 2) connected to the electrodes 20 for generating heat in the heating element 1 to the heating element 1. The nuts 225 are fastened to the bolts 16 of the electrodes 20 inside the through holes 221 and 222, fixing the lead wires 24 (see Figure 2) to the heating element 1.

[0081] As shown in Figures 2, 5 to 7, the base body 210 has through holes 223 and 224 formed in the walls of two corner portions 210a and 210c, which communicate with through holes 7 and 8 of the heating element 1 that form gas passages for heat transfer plate adsorption. The through holes 223 and 224 penetrate the base body 210 in the thickness direction Dt.

[0082] The pair of legs 230 protrude from the other end of the base body 210 in the thickness direction Dt, in a direction intersecting the thickness direction Dt. In this embodiment, the pair of legs 230 protrude from the base body 210 on both sides in the intersecting first direction Da. The pair of legs 230 have through holes 238 and 239 that penetrate each of the legs 230 in the thickness direction Dt. The position and number of legs 230 can be arbitrarily selected as needed, as long as they are connected to the base body 210. The legs 230 may be omitted if attachment to a connecting plate is possible.

[0083] [Connecting Plate] As shown in Figures 1 and 2, the connecting plate 22 is provided on the other side of the heater base 21 in the thickness direction Dt, for example, on the upper side. The connecting plate 22 is formed in a plate shape that is larger than the heater base 21 when viewed in the thickness direction Dt. The connecting plate 22 has female screw holes 241, 241 that communicate with through holes 238, 239 formed in each of the pair of legs 230 of the heater base 21. The connecting plate 22 is fixed to the heater base 21 by fastening a pair of bolts 23, 23 through the through holes 238, 239 to the female screw holes 241.

[0084] The connecting plate 22 has a through-hole 245 that communicates with the through-hole 6 of the heating element 1 and the through-hole 231 of the base body 210. A negative pressure generator (not shown) is connected to the through-hole 245, and the negative pressure generated by the negative pressure generator attracts the chip through the through-hole 6 of the heating element 1.

[0085] The connecting plate 22 has through holes 246 and 247 that communicate with through holes 223 and 224 of the base body 210. A negative pressure generating device (not shown) is connected to the through holes 246 and 247, and the negative pressure generated by the negative pressure generating device attracts the heat transfer plate 30 through grooves 9 and 10, passing through through holes 246 and 247, through holes 223 and 224, and through holes 7 and 8 of the heating element 1.

[0086] The connecting plate 22 has through holes 248 and 249 that communicate with the inlets 213A and 213B of the base body 210. A cooling medium supply source (not shown) for supplying a cooling medium such as compressed air is connected to the through holes 248 and 249. The cooling medium can be selected arbitrarily, but examples include inert gases such as nitrogen, helium, and argon.

[0087] Through holes 250 are formed at each of the four corners of the connecting plate 22. The connecting plate 22 is attached to the heater mounting section of a bonding device such as a flip-chip bonder via bolts (not shown). A flip-chip bonder is a device that mounts semiconductor chips, etc., onto a substrate or package while they are inverted 180 degrees.

[0088] As shown in Figure 1, in such a ceramic heater 100, the cooling medium, such as compressed air supplied from a cooling medium supply source, flows through through holes 248 and 249 into the inlets 213A and 213B of the base body 210, into the flow path 212r formed between the flow path forming section 212 and the back surface 1b of the heating element 1. The incoming cooling medium then separates and flows into outlets 214A and 214B within the flow path 212r.

[0089] As shown in Figure 6, a portion of the cooling medium that flows into the flow path 212r from the inlet 213A flows along the first intersecting direction Da and flows out to the outside of the base body 210 through the outlet 214A. The remaining cooling medium that flows into the flow path 212r from the inlet 213A flows along the second intersecting direction Db, bypasses the third wall-like portion 218, and then flows out to the outside of the base body 210 through the outlet 214B.

[0090] Furthermore, a portion of the cooling medium that flows into the flow path 212r from the inlet 213B flows along the intersecting first direction Da and flows out to the outside of the base body 210 through the outlet 214B. The remaining cooling medium that flows into the flow path 212r from the inlet 213B flows along the intersecting second direction Db, bypasses the third wall-like portion 218, and then flows out to the outside of the base body 210 through the outlet 214A.

[0091] As shown in Figure 6, the flow path 212r1 from the inlet 213A to the outlet 214A, and the flow path 212r3 from the inlet 213B to the outlet 214B, both have a length in the intersecting first direction Da that is at least half of the external dimensions L1 of the heating element 1 in the intersecting first direction Da. The length may also be at least 6 / 10 or 8 / 10 of the external dimensions L1. The external dimensions of the heating element 1 may refer to, for example, the length of each side of the heating element 1 in a plan view, for example, the length of each side if the heating element 1 is rectangular, or the diameter of the circumscribed circle of the heating element 1 if the heating element 1 is not rectangular. The length of the flow path 212r1 and the flow path 212r3 in the intersecting first direction Da may refer to the shortest distance from the inlet to the outlet, since these flow paths do not need to bypass the third wall-like portion 218. Furthermore, the flow path 212r2 from the inlet 213A to the outlet 214B, and the flow path 212r4 from the inlet 213B to the outlet 214A, both have a length in the intersecting second direction Db that is at least half of the external dimensions L2 of the heating element 1 in the intersecting second direction Db. The length may also be at least 6 / 10 or 8 / 10 of the external dimensions L2. Note that the length of the flow path 212r2 and the flow path 212r4 in the intersecting second direction Db may mean the length of the flow path if the curved flow path is straightened out, since these flow paths must bypass the third wall-like portion 218 and do not proceed in a straight line.

[0092] [Method for bonding semiconductor chips] Figure 8 is a perspective view showing an example of a manufacturing state using a flip-chip bonder (mounting device) with the ceramic heater of this embodiment. Based on Figure 8, the method for bonding semiconductor chips using the ceramic heater 100 of this embodiment will be explained. Note that the arrangement and orientation of the device may be arbitrarily selected as needed.

[0093] As shown in Figure 8, the ceramic heater 100 is preferably used for manufacturing semiconductor mounting boards by being attached to the lower end of the movable base 310 of the flip-chip bonder 300. For example, the ceramic heater 100 is mounted to the apparatus such that the side with the heat transfer plate 30 faces a predetermined surface of the semiconductor chip 400.

[0094] First, the movable base 310 on which the ceramic heater 100 is installed is moved to the position of the autoloader 330 on which the tray 320 containing multiple semiconductor chips 400 is placed. Next, air is sucked in through the through-hole 6 of the ceramic heater 100 to pick up one semiconductor chip 400 from the tray 320.

[0095] Next, the movable stand 310 is moved to the position where the substrate 50 is prepared, and the semiconductor chip 400 is placed on top of the conductive bonding material (not shown) that has been placed on the substrate 50 in advance. Furthermore, while applying downward pressure with the movable stand 310, the ceramic heater 100 is energized to heat the heating element 1, and the semiconductor chip 400, conductive bonding material, and substrate 50 are heated almost uniformly via the heat transfer plate 30. As a result, the conductive bonding material melts in a few seconds, and the substrate 50 and the semiconductor chip 400 are bonded together by the molten conductive bonding material.

[0096] Here, the conductive bonding material can be arbitrarily selected, but examples include solder bumps and gold bumps. Such bonding materials have the property of melting when heated and solidifying when cooled.

[0097] After the bonding between the substrate 50 and the semiconductor chip 400 is complete, compressed air, which serves as a cooling medium, is supplied into the flow path 212r from the inlets 213A and 213B of the base body 210 through the through holes 248, 248 of the connecting plate 22. The compressed air flows through the flow path 212r from the inlets 213A and 213B to the outlets 214A and 214B, cooling the heating element 1 from the back surface 1b side. The compressed air flows out of the ceramic heater 100 from the outlets 214A and 214B. The supply of compressed air may be stopped after cooling.

[0098] As a result, the heating element 1 is rapidly cooled by compressed air. After the conductive bonding material has cooled and solidified, the suction of the semiconductor chip 400 is released, and the movable stage 310 is moved upward. By using a high-pressure compressed gas such as compressed air as a cooling medium, the heating element 1 can be rapidly cooled in a few seconds. Therefore, the semiconductor chip 400 and the substrate 50 are protected from overheating, and the bonding process time for one cycle can be shortened.

[0099] Subsequently, by repeating the series of operations described above, multiple semiconductor chips 400 can be sequentially bonded to the substrate 50 by flip-chip bonding.

[0100] In this embodiment, the ceramic heater 100 has a length in the first intersecting direction Da and the second intersecting direction Db of the flow paths 212r1 to 212r4 extending from the inlets 213A and 213B of the base body 210 to the outlets 214A and 214B that is at least half the external dimensions L1 and L2 of the heating element 1. With this configuration, the cooling medium flowing through the flow paths 212r1 to 212r4 from the inlets 213A and 213B to the outlets 214A and 214B is in contact with the back surface 1b of the heating element 1 for a longer period of time. Therefore, cooling can be performed quickly.

[0101] In the ceramic heater 100 of this embodiment, the flow path forming portion 212 has a first wall-like portion 216 that extends in a first intersecting direction Da along the outer peripheral edge (outer edge) of the base body 210. With this configuration, the first wall-like portion 216 can prevent the cooling medium flowing through the flow path 212r from leaking to the outside of the base body 210 between the inlets 213A, 213B and the outlets 214A, 214B. Therefore, cooling can be performed more efficiently. In addition, the tip surface of the first wall-like portion 216 forms at least a part of the heating element holding surface 211. With this configuration, the need to form the heating element holding surface 211 separately from the first wall-like portion 216 is reduced. As a result, the heater base 21 can be formed with a simple configuration.

[0102] The ceramic heater 100 of this embodiment has a second wall-like portion 217 extending in a second intersecting direction Db from the end of the first wall-like portion 216. With this configuration, leakage of the cooling medium to the outside of the base body 210 from the inlet 213A, 213B side of the flow path 212r is suppressed. Therefore, in this respect as well, cooling can be performed efficiently. In addition, the tip surface of the second wall-like portion 217 forms at least a part of the heating element holding surface 211. With this configuration, the need to form the heating element holding surface 211 separately from the second wall-like portion 217 is suppressed. As a result, the heater base 21 can be formed with a simple configuration. The width of the first wall-like portion 216 (width in the second intersecting direction) may be smaller or larger than the width of the second wall-like portion 217 (width in the first intersecting direction), or it may be the same.

[0103] The ceramic heater 100 of this embodiment has a third wall-like portion 218. The third wall-like portion 218 extends between the inlets 213A, 213B and the outlets 214B, 214A in a direction intersecting the direction in which the flow path 212r extends. With this configuration, the cooling medium flowing from the inlets 213A, 213B to the outlets 214B, 214A within the flow path 212r bypasses the third wall-like portion 218. This makes the flow paths 212r2, 212r4 of the cooling medium from the inlets 213A, 213B to the outlets 214B, 214A substantially longer, and allows for more efficient cooling of the heating element 1 by the cooling medium. The third wall-like portion 218 preferably extends from the second wall-like portion 217 in the intersecting first direction Da. The length of the third wall-like portion 218 may be, for example, 1 / 2 or less, 2 / 5 or less, 3 / 10 or less, 2 / 10 or less, 1 / 10 or less, or 1 / 20 or less of the external dimensions L1 of the heating element 1. The width of the third wall-like portion 218 (width in the intersecting second direction) may be smaller than or the same as the width of the second wall-like portion 217 (width in the intersecting first direction), but it is more preferable that it be larger.

[0104] Furthermore, the tip surface of the third wall-like portion 218 forms at least a part of the heating element holding surface 211. This configuration reduces the need to form the heating element holding surface 211 separately from the third wall-like portion 218. As a result, the heater base 21 can be formed with a simple configuration. In a plan view, the surface area of ​​the heating element holding surface 211 relative to the area of ​​the base body 210 (e.g., L1 × L2) is, for example, 10 to 50%, preferably 15 to 45%, more preferably 20 to 40%, and even more preferably 25 to 35%.

[0105] In this embodiment, the ceramic heater 100 has inlets 213A and 213B formed at two diagonally opposite corners 210a and 210c of the rectangular base body 210. Outlets 214A and 214B are formed at the other corners 210b and 210d. With this configuration, the flow paths 212r1, 212r2, 212r3, and 212r4 leading from each of the two inlets 213A and 213B to the adjacent outlets 214A and 214B can be formed to be long in the rectangular base body 210. Therefore, the heating element 1 can be cooled more efficiently.

[0106] In the ceramic heater 100 of this embodiment, the base body 210 has a heating element fixing part 219 in the center of the base body 210 when viewed from the thickness direction Dt. The heating element fixing part 219 is located between the flow paths 212r1, 212r2, 212r3, and 212r4 that lead from each of the two inlets 213A and 213B to adjacent outlets 214A and 214B. As a result, interference between the cooling media flowing from each of the two inlets 213A and 213B to adjacent outlets 214A and 214B is suppressed. That is, the cooling refrigerant that exits from one outlet is divided into two by the heating element fixing part 219 and can be discharged separately from the two outlets. Furthermore, since the heating element 1 is fixed to the heating element fixing part 219, the heating element fixing part 219 has two functions: suppressing interference with the flow of the cooling medium and fixing the heating element 1, which allows the base body 210 to be constructed efficiently.

[0107] In the ceramic heater 100 of this embodiment, at least one of a convex portion 17 or a concave portion 18 is provided on the back surface 1b of the heating element 1, in the portion that overlaps with the flow path 212r when viewed from the thickness direction Dt. With this configuration, the contact area between the cooling medium flowing through the flow path 212r and the heating element 1 is increased, and the heating element 1 can be cooled more efficiently.

[0108] In the ceramic heater 100 of this embodiment, the protrusion 17 or recess 18 extends in a direction intersecting the direction in which the flow path 212r extends, that is, in a direction that crosses the aforementioned direction. With this configuration, the cooling medium flowing through the flow path 212r comes into contact with the protrusion 17 or recess 18 more efficiently. As a result, the heating element 1 can be cooled more efficiently.

[0109] Although embodiments of the present invention have been described above, the configurations and combinations thereof in the embodiments are merely examples, and additions, omissions, substitutions, and other modifications to the configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited by the embodiments.

[0110] 1 Heating element 1A Silicon carbide sintered body 1a Surface 1B Insulating coating 1b Back surface 1c, 1d, 1e, 1f Edges forming the outer periphery 1p, 1q, 1r Plate-like parts 2, 3 Slits 4, 5 Through holes for electrode mounting 6 Through holes forming gas passages for chip adsorption 7, 8 Through holes forming gas passages for heat transfer plate adsorption 9, 10 Grooves 13, 14 Through holes for inserting countersunk screws 15 Countersunk screws 16 Bolts 17 Protrusions 18 Recesses 20 Electrodes 21 Heater base 22 Connection plate 23 Bolts 24 Lead wires 30 Heat transfer plate 50 Substrate 100 Ceramic heater 210 Base body 210a, 210b, 210c, 210d Corners of the base body 210p, 210q, 210r, 210s Edges forming the outer periphery of the base body 211 Heating element holding surface 212 Flow path forming part 212b Bottom surface of the base body 212r, 212r1 to 212r4 Flow path 213A, 213B Inlet 214A, 214B Outlet 216 First wall-like part 217 Second wall-like part 218 Third wall-like part 219 Heating element fixing part 221, 222 Through holes formed in the corners of the base body for electrode attachment 223, 224 Through holes formed in the corners of the base body for adsorbing the heat transfer plate 225 Nut 226, 227 Recess 230 Leg part of heater base 231 Through hole penetrating the base body 233, 234 Female screw hole 236, 237 Thermocouple holding recess 236h, 237h Through holes for inserting thermocouple wiring 236m, 237m Grooves for housing thermocouple wiring 238, 239 Through holes formed in the legs 241 Female screw holes in the connecting plate 245, 246, 247, 248, 249, 250 Through holes in the connecting plate 300 Flip-chip bonder 310 Movable stand 320 Tray 330 Auto loader 400 Semiconductor chip Da Intersecting first direction Db Intersecting second direction Dt Thickness direction L1, L2 External dimensions of the heating element

Claims

1. A ceramic heater comprising: a plate-shaped heating element having a surface facing one side in the thickness direction and a back surface facing the other side in the thickness direction; and a heater base having a base body that holds the heating element from the other side in the thickness direction, wherein the base body has a heating element holding surface facing one side in the thickness direction and in contact with the back surface of the heating element; and a flow path forming portion recessed from the heating element holding surface to the other side in the thickness direction, forming a flow path between it and the back surface of the heating element through which a cooling medium supplied from the outside can flow, wherein the flow path forming portion has an inlet through which the cooling medium flows from the outside of the base body into the flow path, and an outlet formed away from the inlet in a first intersecting direction intersecting the thickness direction, and communicating the flow path with the outside of the base body, wherein the length of the flow path in the first intersecting direction extending from the inlet to the outlet is 1 / 2 or more of the external dimensions of the heating element in the first intersecting direction.

2. The flow path forming portion has a first wall-like portion that extends along the outer peripheral edge of the base body and in the intersecting first direction, and the tip surface of the first wall-like portion forms at least a part of the heating element holding surface, according to claim 1.

3. The flow path forming portion has a second wall-like portion extending from the end of the first wall-like portion near the inlet, along the outer peripheral edge of the base body, and in a second intersecting direction that intersects both the thickness direction and the first intersecting direction, wherein the tip surface of the second wall-like portion forms at least a part of the heating element holding surface, the ceramic heater according to claim 2.

4. The ceramic heater according to claim 1, wherein the base body is rectangular when viewed in the thickness direction, has two inlets and two outlets, the inlets are formed at two diagonally opposite corners of the four corners of the base body, and the outlets are formed at two other corners of the base body adjacent to the two corners where the inlets are formed.

5. The flow path forming portion has a third wall-like portion extending in a direction intersecting the direction in which the flow path extends, between the inlet and the outlet, and the tip surface of the third wall-like portion forms at least a part of the heating element holding surface, according to claim 1.

6. The ceramic heater according to claim 1, wherein the back surface of the heating element, in a portion that overlaps with the flow path when viewed from the thickness direction, is provided with at least one of a convex portion that protrudes in the thickness direction and a concave portion that is recessed in the thickness direction.

7. The ceramic heater according to claim 6, wherein the convex portion and the concave portion extend in a direction intersecting the direction in which the flow path extends.

8. The ceramic heater according to any one of claims 1 to 7, wherein the heating element is formed using silicon carbide.

9. The ceramic heater according to claim 1, wherein the base body has a heating element fixing portion that rises from the bottom surface of the flow path forming portion in the center, and the tip surface of the heating element fixing portion forms at least a part of the heating element holding surface.

10. The ceramic heater according to claim 1, wherein the heating element is made of a silicon carbide sintered body having an insulating coating on its surface, and the base body is made of insulating ceramics.

11. The ceramic heater according to claim 3, wherein the heating element and the base body are rectangular and have the same shape when viewed from the thickness direction, the external dimensions of the heating element are the length of one side of the heating element when viewed from one side in the thickness direction, and the outer peripheral edge of the base body consists of four sides exposed to the outside of the base body.

12. The ceramic heater according to claim 11, wherein the inlet and outlet are formed at adjacent corners of the base body, the outer surfaces of the first and second wall-like portions of the flow path forming portion are exposed to the outside of the base body, and the inner surfaces form part of the flow path, and further comprises a third wall-like portion extending in the intersecting first direction from the end of the second wall-like portion furthest from the inlet, the length of the second wall-like portion in the intersecting second direction is shorter than the length of the first wall-like portion in the intersecting first direction, and the length of the third wall-like portion in the intersecting first direction.

13. The ceramic heater according to claim 12, wherein the inlet is formed on the bottom surface of the flow path forming portion, and the outlet is formed surrounded by the bottom surface of the flow path forming portion, the back surface of the heating element, the first wall-like portion, and the third wall-like portion.

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