JP7037477B2 - Multilayer board and its manufacturing method - Google Patents

Description

The present disclosure relates to a multilayer substrate and a method for manufacturing the same. The multilayer board referred to here is a board-like member having two or more conductors arranged hierarchically. Therefore, the multilayer board is not limited to the circuit board. For example, a multilayer board includes a board-like member on which a wafer is placed in a semiconductor manufacturing apparatus. Examples of such a member include a heater that heats the wafer, a chuck that adsorbs and holds the wafer, an electrode member for applying plasma to the wafer, and a combination of two or more of these.

The multilayer board as described above can be regarded as being configured by laminating a plurality of conductors and a plurality of insulating layers. The plurality of conductors are electrically connected to each other by, for example, via conductors penetrating the insulating layer (see, for example, Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 8-88451 Japanese Unexamined Patent Publication No. 5-267855

A multi-layer board capable of suitably connecting conductors arranged in a hierarchy and a method for manufacturing the same are awaited.

The multilayer substrate according to one aspect of the present disclosure includes an insulating substrate having a first surface and a second surface on the back surface thereof, and a first conductor along the first surface in the substrate. The second conductor along the first surface in the substrate and on the second surface side with respect to the first conductor is connected, and the first conductor and the second conductor are connected in the substrate. It has a connecting member and a connecting member. Further, the connecting member has an insulating base material and a portion located in the base material, and also has a portion connected to the first conductor and the second conductor. Has a connecting conductor and.

The multilayer substrate according to one aspect of the present disclosure includes an insulating substrate having a first surface and a second surface on the back surface thereof, and a first conductor along the first surface in the substrate. The second conductor along the first surface in the substrate and on the second surface side with respect to the first conductor is connected, and the first conductor and the second conductor are connected in the substrate. Has a connecting conductor and. Further, in the plan view of the first surface, the outer edge of the connecting conductor has a first arc and a second arc having a curvature smaller than that of the first arc and connected to the first conductor. have.

The multilayer substrate according to one aspect of the present disclosure includes an insulating substrate having a first surface and a second surface on the back surface thereof, and a first conductor along the first surface in the substrate. The second conductor along the first surface in the substrate and on the second surface side with respect to the first conductor is connected, and the first conductor and the second conductor are connected in the substrate. Has a connecting conductor and. Further, the first conductor has a long portion extending along the first surface, and in a plan view of the first surface, the plurality of connecting conductors are equal to or less than the width of the long portion. It is located on the same circumference of the same diameter and is connected to the long portion.

The heater system according to one aspect of the present disclosure includes the multilayer board and a power supply unit electrically connected to the first conductor and the second conductor. Further, at least one of the first conductor and the second conductor is a resistance heating element.

The method for manufacturing the multilayer substrate according to one aspect of the present disclosure is composed of a step of manufacturing the connecting member and ceramics before firing in which the connecting member is arranged inside after the step of manufacturing. It has a step of firing the substrate. Further, the step of manufacturing the connecting member includes a step of forming a molded body as the base material by using a ceramic raw material. Further, it has a step of inserting a metal bulk material to be at least a part of the connecting conductor into the molded body. It also has a step of firing the molded body into which the connecting conductor is inserted.

According to the above configuration or procedure, the conductors arranged hierarchically can be electrically and stably connected to each other. Therefore, it can be used for a long period of time.

The exploded perspective view which shows the structure of the heater which concerns on embodiment. FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 3 (a) is an enlarged sectional view showing the region IIIa of FIG. 2, and FIG. 3 (b) is an enlarged view of the region III b of FIG. 3 (a). FIG. 3A is a perspective view of the connecting member. 5 (a) is a plan view of the connecting member of FIG. 4 and its surroundings, and FIG. 5 (b) is an enlarged view of the region Vb of FIG. 5 (a). The flowchart which shows an example of the procedure of the manufacturing method of the heater of FIG. 7 (a), 7 (b), 7 (c) and 7 (d) are cross-sectional views showing connecting members in the process of being manufactured. 8 (a), 8 (b), 8 (c) and 8 (d) are cross-sectional views showing a part of a heater in the process of being manufactured. 9 (a) and 9 (b) are cross-sectional views showing first and second modified examples. 10 (a) and 10 (b) are cross-sectional views showing third and fourth modified examples.

Hereinafter, embodiments of the present disclosure will be described by taking a heater including a heater plate as a multilayer substrate as an example. The drawings referred to below are schematic for convenience of explanation. Therefore, details may be omitted, and the dimensional ratios do not always match the actual ones. Further, the heater may further include well-known components not shown in each figure.

In the following description, when the material of each member is referred to as a main component, the main component is, for example, a component that occupies 50% by mass or more or 80% by mass or more of the material. Further, when the shape of each member is expressed as a circle or a polygon, it is not necessary to be strictly a circle or a polygon unless otherwise specified. For example, the corners of the polygon may be chamfered, or relatively small protrusions or recesses may be formed on the outer edge.

[Embodiment]
(Heater system)
FIG. 1 is a schematic exploded perspective view showing the configuration of the heater 1 according to the embodiment. FIG. 2 is a schematic diagram showing the configuration of the heater system 101 including the heater 1 of FIG. In FIG. 2, for the heater 1, a sectional view taken along line II-II of FIG. 1 is shown. FIG. 1 shows the heater 1 disassembled for convenience in order to show the structure of the heater 1, and the heater 1 after the actual completion does not need to be disassembled as in the disassembled perspective view of FIG. ..

For convenience, these figures have a fixed Cartesian coordinate system XYZ attached to the heater 1. The + Z direction is, for example, vertically above. However, the heater 1 does not necessarily have to be used with the + Z direction facing upward. In the following, for convenience, terms such as upper surface and lower surface may be used assuming that the + Z direction is the actual upper side. Further, unless otherwise specified, the term "planar view" refers to viewing in the Z direction.

The heater system 101 includes a heater 1, a power supply unit 3 (FIG. 2) that supplies electric power to the heater 1, and a control unit 5 (FIG. 2) that controls the power supply unit 3. The heater 1 and the power supply unit 3 are connected by a wiring member 7 (FIG. 2). The wiring member 7 may be regarded as a part of the heater 1. Further, in addition to the configuration described above, the heater system 101 may have, for example, a fluid supply unit that supplies gas and / or liquid to the heater 1.

(heater)
The heater 1 has, for example, a roughly plate-shaped (disk-shaped in the illustrated example) heater plate 9 (reference numeral is FIG. 2, an example of a multilayer board), and a pipe 11 extending downward from the heater plate 9. There is.

The wafer Wf (FIG. 2) as an example of the object to be heated is placed (stacked) on the upper surface 13a of the heater plate 9 and directly contributes to the heating of the wafer. The pipe 11 contributes to, for example, supporting the heater plate 9 and protecting the wiring member 7. It should be noted that only the heater plate 9 may be regarded as a heater.

(Heater plate)
The upper surface 13a and the lower surface 13b of the heater plate 9 are, for example, generally flat. The planar shape and various dimensions of the heater plate 9 may be appropriately set in consideration of the shape and dimensions of the object to be heated. For example, the planar shape is circular (illustrated example) or polygonal (eg rectangular). As an example of the dimensions, the diameter is 20 cm or more and 35 cm or less, and the thickness is 4 mm or more and 30 mm or less.

The heater plate 9 is, for example, an insulating base 13 (reference numeral is FIG. 2) and two first resistance heating elements 15A and a second resistance heating element 15B (first conductor and second conductor) embedded in the base 13. (Example)) and a terminal 17 for supplying electric power to these conductor layers. In the following, the first resistance heating element 15A and the second resistance heating element 15B are simply referred to as "resistance heating elements 15", and they may not be distinguished from each other. When a current flows through the resistance heating element 15, heat is generated according to Joule's law, and the wafer Wf placed on the upper surface 13a of the substrate 13 is heated.

(Hypokeimenon)
The outer shape of the substrate 13 constitutes the outer shape of the heater plate 9. Therefore, the above description relating to the shape and dimensions of the heater plate 9 may be regarded as the description of the outer shape and dimensions of the substrate 13 as it is. The material of the substrate 13 is, for example, ceramic. The ceramic is, for example, a sintered body containing aluminum nitride (AlN), aluminum oxide (Al ₂ O ₃ , alumina), silicon carbide (SiC), silicon nitride (Si ₃ N ₄ ) and the like as main components.

In FIG. 1, the substrate 13 is composed of a first insulating layer 19A to a fifth insulating layer 19E (hereinafter, simply referred to as an insulating layer 19 and may not distinguish between them). The substrate 13 may be manufactured by laminating a material (for example, a ceramic green sheet) to be an insulating layer 19, or is manufactured by a method different from such a method, and the presence of a resistance heating element 15 or the like after completion. It may only be conceptually considered to be composed of a plurality of insulating layers 19.

(Resistance heating element)
The resistance heating element 15 extends along (eg, in parallel) the upper surface 13a and the lower surface 13b of the substrate 13. Further, the resistance heating element 15 extends over substantially the entire surface of the substrate 13, for example, in a plan view. In FIG. 1, the first resistance heating element 15A is located between the second insulating layer 19B and the third insulating layer 19C. The second resistance heating element 15B is located between the third insulating layer 19C and the fourth insulating layer 19D. In other words, the two resistance heating elements 15 are arranged in a stacked manner with respect to each other, and the second resistance heating element 15B is located on the lower surface 13b side with respect to the first resistance heating element 15A.

The specific pattern (path) of each resistance heating element 15 in a plan view may be appropriate. For example, each resistance heating element 15 extends from one end to the other end without crossing itself. Further, in the illustrated example, the resistance heating element 15 extends (in a miander shape) so as to reciprocate in the circumferential direction in each region of the heater plate 9 divided into two. In addition, for example, the resistance heating element 15 may extend in a spiral shape or may extend in a linear reciprocating manner in one radial direction.

The relative relationship between the two resistance heating elements 15 may be appropriate with respect to the pattern and position in plan view. For example, both may have the same pattern or different patterns from each other. Further, both may or may not overlap each other. In the illustrated example, one resistance heating element 15 is located in all or most (for example, 60% or more or 80% or more) of the gap of the other resistance heating element 15 (for example, all or most of the gap is closed). It is said to be a pattern. Specifically, the two have almost the same pattern, but their positions are slightly different from each other.

The shape of the resistance heating element 15 when viewed locally may also be appropriate. For example, the resistance heating element 15 may be a layered conductor parallel to the upper surface 13a and the lower surface 13b, may be a coil shape (spring shape) wound around the above path as an axis, or may be a mesh shape. It may be formed. Dimensions in various shapes may also be set as appropriate. Further, the shape when viewed locally may be the same for the two resistance heating elements 15 or may be different from each other. In the description of the present embodiment, as shown in FIG. 2, a case where each resistance heating element 15 is a layered conductor parallel to the upper surface 13a is taken as an example.

The materials of the two resistance heating elements 15 may be the same or different from each other. In the description of this embodiment, the case where both are the same as each other is taken as an example. The material of the resistance heating element 15 is a conductor (for example, metal) that generates heat by flowing an electric current. Further, the material of the resistance heating element 15 may be obtained by firing a conductive paste. In other words, the material of the resistance heating element 15 may include an inorganic insulator such as glass powder and / or ceramic powder in addition to the metal.

The type of conductor (metal) that is the main component of the resistance heating element 15 may be appropriately selected, for example, tungsten (W), molybdenum (Mo), platinum (Pt) or indium (In), or a main component thereof. It is an alloy to be. To give an example of the composition of the material of the resistance heating element 15 when the resistance heating element 15 is manufactured by firing a conductive paste, the materials are 91% by mass or more and 94% by mass or less of W and 1% by mass or less. Includes Y ₂ O ₃ and Al N of 1% by mass or more and 3% by mass or less, and Al ₂ O ₃ of 4% by mass or more and 7% by mass or less.

(Terminal)
The terminals 17 are connected to both ends of each resistance heating element 15 in the length direction, for example. Further, in the illustrated example, a pair of terminals 17 are commonly connected to two resistance heating elements 15. From another point of view, the two resistance heating elements 15 are connected in parallel. However, the above is only an example of the connection between the terminal 17 and the resistance heating element 15. For example, three or more terminals 17 that supply electric power to one resistance heating element 15 may be provided. Further, the terminals 17 may be provided separately for the two resistance heating elements 15, such as one or more terminals 17 being provided for each resistance heating element 15. As will be described later, since the resistance heating elements 15 are connected to each other by a connecting conductor, the terminal 17 may be connected to only one of the two resistance heating elements 15. Further, the two resistance heating elements 15 may be partially or wholly connected in series.

The terminal 17 penetrates, for example, the thickness of the substrate 13 from the first resistance heating element 15A to the lower surface 13b (third insulating layer 19C to fifth insulating layer 19E). The terminal 17 is connected to the two resistance heating elements 15 and is exposed to the outside of the substrate 13. This makes it possible to supply electric power to the resistance heating element 15 from the outside of the heater plate 9. The terminals 17 (both ends of the resistance heating element 15) are located, for example, on the center side of the heater plate 9. As can be understood from the various aspects described above regarding the connection between the terminal 17 and the resistance heating element 15, the terminal 17 penetrates only the thickness of the substrate 13 from the second resistance heating element 15B to the lower surface 13b. It may be various modes other than those shown in the figure.

(pipe)
The pipe 11 is hollow with openings at the top and bottom (both sides in the axial direction). From another point of view, the pipe 11 has a space 11s that penetrates vertically. The shapes of the cross section (cross section orthogonal to the axial direction) and the vertical cross section (cross section parallel to the axial direction; the cross section shown in FIG. 2) of the pipe 11 may be appropriately set. In the illustrated example, the pipe 11 has a cylindrical shape having a constant diameter with respect to a position in the axial direction. Of course, the pipe 11 may have a different diameter depending on the position in the height direction. Further, specific values of the dimensions of the pipe 11 may be appropriately set. Although not particularly shown, the pipe 11 may be formed with a flow path through which a gas or a liquid flows.

The pipe 11 may be made of an insulating material such as ceramic, or may be made of a metal (conductive material). As a specific material for the ceramic, for example, those mentioned in the description of the substrate 13 (AlN or the like) may be used. Further, the material of the pipe 11 may be the same as or different from the material of the substrate 13.

The substrate 13 and the pipe 11 may be fixed by an appropriate method. For example, both may be fixed by an adhesive (not shown) interposed between the two, may be fixed by solid phase bonding without an adhesive intervening between the two, and bolts and It may be mechanically fixed using nuts (neither shown).

(Wiring member)
The wiring member 7 is inserted into the space 11s of the pipe 11. In planar fluoroscopy, a plurality of terminals 17 are exposed from the substrate 13 in the region of the heater plate 9 exposed in the space 11s. One end of the wiring member 7 is connected to a plurality of terminals 17.

The plurality of wiring members 7 may be flexible electric wires, rod-shaped ones having no flexibility, or a combination thereof. Further, the plurality of flexible electric wires may or may not be bundled together to form a single cable.

The connection between the wiring member 7 and the terminal 17 may also be appropriate. For example, the two may be joined by a conductive joining material. Further, for example, both may be screwed together by forming a male screw on one side and a female screw on the other side.

(Connection between conductor layers)
FIG. 3A is an enlarged cross-sectional view showing the region IIIa of FIG.

In the present embodiment, the two resistance heating elements 15 are electrically connected to each other by a connecting member 21 (not shown in FIG. 2) located in the substrate 13. This connection may be made at different locations and / or for different purposes. For example, as illustrated in FIGS. 1 and 2, in the embodiment in which the two resistance heating elements 15 are connected in parallel, the intermediate positions of the patterns (paths) of the two resistance heating elements 15 may be connected to each other. In this case, for example, the potential of the resistance heating element 15 can be stabilized, or the continuity can be maintained even if a part of the resistance heating element 15 is disconnected. Further, for example, a pair of terminals 17 are connected only to both ends of the second resistance heating element 15B, and at a position slightly deviated from the pair of terminals 17, the vicinity of both ends of the second resistance heating element 15B and the first resistance heating element are generated. The vicinity of both ends of the body 15A may be connected. In this case, for example, the pair of terminals 17 does not have to penetrate the substrate 13 to the position of the first resistance heating element 15A, which improves the degree of freedom in design.

The connecting member 21 penetrates, for example, at least one resistance heating element 15 (both in the illustrated example). In other words, the connecting member 21 extends from the lower surface 13b side of the first resistance heating element 15A to the upper surface 13a side of the first resistance heating element 15A, focusing on the portion connected to the first resistance heating element 15A. ing. Similarly, focusing on the portion of the connecting member 21 connected to the second resistance heating element 15B, the connecting member 21 extends from the upper surface 13a side of the second resistance heating element 15B to the lower surface 13b side of the second resistance heating element 15B. There is. The connecting member 21 is connected (bonded and / or abutted) to two resistance heating elements 15 on its side surface.

Although the upper end of the connecting member 21 (the end on the upper surface 13a side) is located on the upper surface 13a side of the first resistance heating element 15A as described above, it does not reach the upper surface 13a and is inside the substrate 13. positioned. This upper end is not connected to any other conductor. The other conductor referred to here is a wiring or an electrode intended to carry a current, for example, a resistance heating element 15, and does not mean a mere conductor for bonding. That is, the upper end of the connecting member 21 is an open end from the viewpoint of the electric circuit. Although the upper end of the connecting member 21 has been described, the same applies to the lower end of the connecting member 21 in the present embodiment. That is, the lower end of the connecting member 21 is located in the substrate 13 and electrically (circuitically) constitutes an open end.

The shape and various dimensions of the connecting member 21 may be appropriately set. For example, the connecting member 21 has an axis whose length in the Z direction (opposite direction of the two resistance heating elements 15) is longer than the length (diameter) in the direction parallel to the XY plane (direction parallel to the upper surface 13a). It is shaped (columnar). However, the connecting member 21 may have a shape whose diameter is longer than the length. The shape and size of the cross section of the connecting member 21 parallel to the XY plane may or may not be constant in the Z direction (illustrated example). Further, the shape of the cross section may be an appropriate shape such as a circle or a polygon.

Further, for example, the amount of protrusion of the connecting member 21 upward from the first resistance heating element 15A may be smaller, equal to, or larger than, for example, the thickness of the first resistance heating element 15A. good. The same applies to the amount of downward protrusion. The width of the connecting member 21 in the width direction of the resistance heating element 15 (diameter in the columnar connecting member 21) may be smaller, equal to, or larger than the width of the resistance heating element 15. For example, the diameter of the connecting member 21 is smaller than the width of the resistance heating element 15, and the connecting member 21 is in contact with the resistance heating element 15 over the entire circumference thereof in a plan view. However, only a part of the side surface of the connecting member 21 may be in contact with the resistance heating element 15 in a plan view.

(Specific configuration of connecting conductor)
FIG. 3 (b) is an enlarged view of the region IIIb of FIG. 3 (a). FIG. 4 is a perspective view of the connecting member 21. FIG. 5A is a plan view of the connecting member 21 and its surroundings.

The connecting member 21 has an insulating base material 23 and one or more (four in the illustrated example) connecting conductors 25 held by the base material 23. The connecting conductor 25 has a portion located inside the base material 23 and a portion exposed to the outside of the base material 23 without being covered with the base material 23. Then, by connecting the exposed portion and the resistance heating element 15, the two resistance heating elements 15 are electrically connected to each other. With such a configuration, for example, the difference in thermal expansion between the connecting member 21 and the substrate 13 can be reduced as compared with the case where the entire connecting member 21 is composed of a conductor. The configuration of each member is as follows, for example.

(Base material)
The shape and dimensions of the base material 23 are basically the same as the shape and dimensions of the connecting member 21 except for the recess 23r (FIGS. 4 and 5) in which the connecting conductor 25 is housed. Therefore, the above description of the outer shape of the connecting member 21 may be applied to the shape and dimensions of the base material 23. The base material 23 is, for example, a columnar shape whose axial direction is the Z direction. In other words, the base material 23 has a columnar portion whose axial direction is the direction from the upper surface 13a to the lower surface 13b (not necessarily parallel to the Z direction). In this embodiment, since the entire base material 23 is a columnar portion, the reference numeral of the columnar portion is omitted. The shape and dimensions of the recess 23r are substantially the same as the shape and dimensions of the connecting conductor 25, and for the shape and dimensions of the recess 23r, refer to the description of the shape and dimensions of the connecting conductor 25 described later.

In the illustrated example, the base material 23 is columnar if the recess 23r is ignored. However, the shape of the base material 23 in a plan view may be a non-circular shape such as a polygon. In the present disclosure, the term "center" in the plan view means the geometric center (centroid) of the figure formed by the outer edge of the member in the plan view, unless otherwise specified. To be confident, the geometric center is the point where the primary moment around it becomes zero. Thus, for example, other than circular or rotationally symmetric shapes, the center can be defined. Further, the center may be rationally specified by ignoring a specific portion at the outer edge of the member. As for the base material 23 in the illustrated example, the center of the circle may be regarded as the center of the base material 23 assuming that there is no recess 23r.

The ratio of the volume of the base material 23 to the volume of the connecting member 21 may be appropriately set. For example, the volume of the base material 23 may occupy 50% or more of the volume of the connecting member 21 (example in the figure), or less than 50%. In the former case, for example, 60%. It may be more than or equal to 80% or more.

The material of the base material 23 is, for example, ceramic. As a specific material for the ceramic, for example, those mentioned in the description of the substrate 13 (AlN or the like) may be used. Further, the material of the base material 23 may be the same as or different from the material of the base material 13 in which the base material 23 is actually embedded. When the material of the base material 23 is different from the material of the base material 13, the main components of both may be the same or different.

(Connecting conductor)
Each connecting conductor 25 is made of, for example, a metal extending linearly in parallel in the Z direction in the base material 23. In other words, the connecting conductor 25 has a columnar portion whose axial direction is the direction from the upper surface 13a to the lower surface 13b (not necessarily parallel to the Z direction). In this embodiment, since the entire connecting conductor 25 is a columnar portion, the reference numeral of the columnar portion is omitted. Unlike the illustrated example, the connecting conductor 25 may be bent in the middle, have a portion extending in the horizontal direction in the middle, or may be inclined and extended in the vertical direction.

A part of the side surface of the connecting conductor 25 is exposed from the side surface of the base material 23. As a result, the connecting conductor 25 can be connected to the resistance heating element 15 on its side surface. More specifically, for example, in the connecting conductor 25, a region of a predetermined angle range around the axis of the connecting conductor 25 on the side surface (outer peripheral surface) is exposed from the base material 23 over the entire axial direction.

In the illustrated example, the upper end surface and the lower end surface of the connecting conductor 25 are also exposed from the upper end surface and the lower end surface of the base material 23. The upper end surface and the lower end surface of the connecting conductor 25 are substantially flush with, for example, the upper end surface and the lower end surface of the base material 23. Although not particularly shown, the upper end surface and / or the lower end surface of the connecting conductor 25 may be located deeper than the surface (upper end surface and / or lower end surface) of the base material 23, or conversely, the base material 23. It may be located outside the surface. Further, the upper end surface and / or the lower end surface of the connecting conductor 25 may be covered with the base material 23.

The number of connecting conductors 25 may be one, or may be an appropriate number of two or more. For example, four or more connecting conductors 25 (four in the illustrated example) are provided. The four or more connecting conductors 25 are arranged along the outer edge of the base material 23 in a plan view. In the present embodiment, since the base material 23 is circular in a plan view, from another viewpoint, the plurality of connecting conductors 25 are arranged on the same circumference in a plan view. Further, the two or more connecting conductors 25 arranged along the outer edge of the base material 23 and / or the three or more or four or more connecting conductors 25 arranged on the same circumference have, for example, at uniform pitches. It is arranged. From another point of view, the plurality of connecting conductors 25 are arranged point-symmetrically (180 ° rotationally symmetric) with respect to a predetermined symmetry point (for example, the center of the base material 23). From yet another point of view, the n connecting conductors 25 are arranged symmetrically n times. Although not particularly shown, the plurality of connecting conductors 25 may be arranged at non-uniform pitches.

As described above, in a plan view, the entire circumference (composed of the base material 23 and the connecting conductor 25) of the connecting member 21 may be in contact with the resistance heating element 15. In this case, the diameter of the circumference on which the plurality of connecting conductors 25 are arranged is equal to or less than the width of the resistance heating element 15. The relative relationship between the arrangement of the plurality of connecting conductors 25 and the extending direction of the resistance heating element 15 may be appropriately set. In FIG. 5A, the four connecting conductors 25 are located in the extending direction or the width direction of the resistance heating element 15 with respect to the center of the base material 23, but are located in the directions inclined in these directions. You may be doing it.

Although not particularly shown, in the connecting member 21, for example, in a plan view, all of the plurality of connecting conductors 25 are connected to the resistance heating element 15, and a part of the side surface of the base material 23 is wider than the width of the resistance heating element 15. It may be configured so as to be located on the outside and not in contact with the resistance heating element 15. Further, all the connecting conductors 25 may be connected to the resistance heating element 15 while making the diameter of the circumference on which the plurality of connecting conductors 25 are arranged larger than the width of the resistance heating element 15.

In a plan view, determination of whether or not the connecting conductor 25 is arranged on the same circumference and specification of the diameter of the circumference are rationalized based on an appropriate position of the connecting conductor 25. good. For example, with reference to the center of the connecting conductor 25 or the connection position of the connecting conductor 25 with the resistance heating element 15, it may be determined whether or not they are located on the same circumference and the diameter of the circumference may be specified. At this time, the deviation corresponding to the tolerance in the process of manufacturing the connecting member 21 may be ignored.

The specific shape and various dimensions of the connecting conductor 25 may be appropriately set. For example, the shape and size of the cross section (XY cross section) of the connecting conductor 25 may be constant in the length direction (Z direction), and may be an appropriate shape such as a circle or a polygon. The connecting conductor 25 is solid as shown. Unlike the illustrated example, it is not impossible to form a space (vacuum state or gas is present) inside the connecting conductor 25, or to arrange an insulator inside.

In the cross section (XY cross section) of the connecting member 21, the shape of the connecting conductor 25 is roughly a line extending from a predetermined shape (here, a circle) to the outer edge (peripheral portion of the recess 23r) of the base material 23 (FIG. 5 (FIG. 5). The shape is such that a part of the base material 23 opposite to the center is removed with the second arc 25b) of a) as a boundary. In other words, the portion of the outer edge of the connecting conductor 25 exposed from the base material 23 has a shape as if it constitutes a part of the outer edge of the base material 23.

In the present embodiment, the predetermined shape of the connecting conductor 25 is a circle (referred to as a first circle in this paragraph). Further, in the present embodiment, in a plan view, the shape of the base material 23 is a circle having a diameter larger than the diameter of the first circular diameter. Therefore, more specifically, in a plan view, the connecting conductor 25 has a smaller curvature than the circumference of the first circular circle, and the first arc is defined by the center side of the base material 23 as the center of curvature. It has a shape in which a part of the base material 23 opposite to the center is removed from the circular shape of the base material 23. In other words, the connecting conductor 25 has a smaller curvature than the first arc 25a (FIG. 5A) and the first arc 25a in a plan view, and is connected to the resistance heating element 15. It has an arc 25b (FIG. 5A).

The removed portion is a portion opposite to the center of the base material 23 with respect to the center of the predetermined shape (here, a circle). Therefore, in the predetermined shape, the portion having the maximum length in the direction orthogonal to the direction (radiation direction) from the center of the base material 23 to the outer edge of the base material 23 remains without being removed. From another point of view, in a plan view, the connecting conductor 25 maintains a shape that engages outward with the base material 23. However, such a shape may not be maintained.

5 (b) is an enlarged view of the region Vb of FIG. 5 (a).

As shown in this figure, for example, the connecting conductor 25 microscopically protrudes from the surface (here, the side surface) of the base material 23. The magnitude of this protrusion may be appropriately set. For example, this protrusion amount is relatively small with respect to the diameter of the base material 23 and / or the connecting conductor 25. For example, in a plan view, when the outer edge of the base material 23 is extended toward the connecting conductor 25, a portion (second arc) exposed from the base material 23 on the side surface of the connecting conductor 25 from this extended line. The length (protrusion amount) up to 25b) is 1/5 or less or 1/10 or less of the diameter (for example, the maximum diameter) of the connecting conductor 25. However, unlike the illustrated example, the portion of the side surface of the connecting conductor 25 exposed from the base material 23 may be located at a position recessed from the side surface of the base material 23, or may be continuous with the side surface of the base material 23. May be.

The material of the connecting conductor 25 may be appropriately set. For example, as the material of the connecting conductor 25, W, Mo, Pt or Ni can be mentioned. The material of the connecting conductor 25 may be the same as or different from the material of the resistance heating element 15. In different cases, the main components of both may be the same or different.

Further, the connecting conductor 25 is made of a metal bulk material (metal block), for example, from the viewpoint of the manufacturing method described later. In other words, the connecting conductor 25 is not made by co-fired the conductive paste with the raw ceramic (base material 23). Thus, for example, the connecting conductor 25 does not contain ceramic powder and / or glass powder (inorganic insulator), unlike a conductor made of a conductive paste. The method for producing the metal bulk material may be appropriate. For example, bulk metal materials may be made by powder metallurgy or casting.

However, the connecting conductor 25 may be manufactured by simultaneously firing the conductive paste with the raw ceramic (base material 23). Further, the connecting conductor 25 may be manufactured by arranging a conductive paste around the metal bulk material and firing it simultaneously with the raw ceramic (base material 23). In other words, the connecting conductor 25 may include an inorganic insulator or the like in all or part of the connecting conductor 25.

(Shape of resistance heating element near the connecting conductor)
As shown in FIG. 3B, the portion of the resistance heating element 15 connected to the connecting member 21 may be inclined with respect to the upper surface 13a of the substrate 13. From another point of view, the resistance heating element 15 is located substantially in the same plane and is inclined with respect to the main portion 15a which occupies most (for example, 80% or more) of the resistance heating element 15 and the main portion 15a. It may have an inclined portion 15b connected to the connecting member 21.

The inclined portion 15b may be inclined to either the upper surface 13a side or the lower surface 13b side with respect to the main portion 15a. Further, when the resistance heating element 15 is displaced to one side in the Z direction from the center of the thickness of the substrate 13, the inclined portion 15b of the resistance heating element 15 may be inclined to the one side. It may be tilted to the other side. Further, the directions in which the inclined portions 15b of the two resistance heating elements 15 are inclined may be the same or opposite to each other. In the illustrated example, the inclined portion 15b of the first resistance heating element 15A is inclined toward the upper surface 13a, and the inclined portion 15b of the second resistance heating element 15B is inclined toward the lower surface 13b side.

The inclined portion 15b may have a curved surface shape (illustrated example) or a flat surface shape. In the former case, for example, the inclined portion 15b is curved so that the inclination angle becomes larger as it approaches the connecting member 21. The inclination angle and length of the inclined portion 15b (for example, the length in the direction parallel to the upper surface 13a) may be appropriately large. For example, the inclination angle of the inclined portion 15b is a size that can be visually confirmed in a cross-sectional photograph as shown in FIG. 3 (b). Further, for example, the inclination angle of the inclined portion 15b with respect to the upper surface 13a (main portion 15a) has a maximum value or an average value of 5 ° or more and 30 ° or less.

(Manufacturing method of heater plate)
FIG. 6 is a flowchart showing an example of the procedure of the method for manufacturing the heater plate 9. 7 (a) to 7 (d) are cross-sectional views corresponding to FIG. 3 (b) showing the connecting member 21 in the middle of manufacturing. 8 (a) to 8 (d) are cross-sectional views corresponding to FIG. 3 (b) showing a part of the heater plate 9 in the middle of manufacturing. The material and shape of each member change as the manufacturing process progresses. However, for convenience of explanation, the same reference numerals may be used before and after changes in materials, shapes, and the like.

In steps ST1 to ST4, the connecting member 21 is manufactured, and in steps ST5 to ST10, the heater plate 9 including the connecting member 21 is manufactured.

In step ST1, as shown in FIG. 7A, the base material 23 (molded body) before firing is produced. The shape of the molded product at this time is, for example, a shape in which a portion on the outer surface side to be removed by grinding described later is added to the shape of the base material 23 after completion. The outer shape of the molded body is, for example, the same shape (shape with a certain thickness added) as the outer shape of the base material 23 after completion (excluding the concave portion 23r). However, the outer shape of the molded body may be different from the outer shape of the base material 23 after completion.

The base material 23 (molded body) before firing has a through hole 23h that becomes a recess 23r after completion. The through hole 23h penetrates the molded body in the Z direction. However, instead of the through hole 23h, a hole that opens only on one side in the Z direction may be formed.

The method for producing the molded product to be the base material 23 may be the same as various known methods. For example, the molded product may be produced by arranging the ceramic raw material powder in a mold and applying pressure, or may be produced by laminating a plurality of ceramic green sheets. The through hole 23h may be formed by, for example, a core located in the mold during molding by the mold, or may be formed by cutting after molding by the mold or after laminating a plurality of ceramic green sheets. It may be formed by cutting, punching or laser processing before laminating a plurality of ceramic green sheets.

In step ST2, as shown in FIG. 7B, the connecting conductor 25 (metal bulk material) is inserted into the through hole 23h of the base material 23 (molded body) before firing. The diameter of the metal bulk material at this time is, for example, smaller than the diameter of the through hole 23h, and a gap is formed between the two. The gap may be filled with the conductive paste. In the illustrated example, the length of the metal bulk material is longer than the length of the through hole 23h. However, the length of the metal bulk material may be equal to or shorter than the length of the through hole 23h.

In step ST3, as shown in FIG. 7C, the molded body to be the base material 23 is fired. By firing, the base material 23 shrinks. By this shrinkage, the base material 23 may tighten the connecting conductor 25. As a result, the fixing strength between the base material 23 and the connecting conductor 25 is improved. Due to such tightening, the diameter of the through hole 23h is equal to or larger than the diameter of the connecting conductor 25 and becomes smaller than the diameter of the connecting conductor 25 due to shrinkage after firing (assuming that there is no connecting conductor 25). It may be the size.

Instead of steps ST1 and ST2, the metal bulk material to be the connecting conductor 25 and the ceramic raw material powder to be the base material 23 are placed in the mold and pressed to press the metal bulk material, whereby the connecting conductor 25 is inserted. You may try to form a body. Alternatively, instead of steps ST1 to ST3, the metal bulk material to be the connecting conductor 25 and the ceramic raw material powder to be the base material 23 may be arranged in the mold and hot pressed to obtain the connecting member 21. .. In such an embodiment, the shape of the connecting conductor 25 is not limited to a shape that can be inserted into the hole (for example, a shape that extends linearly from at least one end to the middle).

In step ST4, as shown in FIG. 7D, the side surface of the connecting member 21 after firing is ground. In addition, grinding shall be a concept including polishing. By grinding the side surface of the base material 23, a part of the side surface of the connecting conductor 25 is exposed from the side surface of the base material 23. Further grinding is performed, and the side surface of the connecting conductor 25 is also ground together with the side surface of the base material 23. Therefore, in a plan view, the shape of the connecting conductor 25 is changed from the original shape (circular in this embodiment) to that of the base material 23. The shape is partially removed with a line extending the outer edge (here, an arc having a smaller curvature than the circle) as a boundary. In general, ceramics are easier to grind than metal. Therefore, microscopically, as shown in FIG. 5B, the connecting conductor 25 has a shape slightly protruding from the side surface of the base material 23. Further, in step ST4, the upper surface and / or the lower surface of the connecting member 21 may also be ground.

In step ST5, the first insulating layer 19A to the fifth insulating layer 19E (ceramic green sheet) before firing are prepared (see FIG. 8A).

In addition, in order to facilitate understanding, it is described here that all ceramic green sheets are prepared after step ST4 and before step ST6. In practice, the ceramic green sheet may be prepared before step ST4, or some ceramic green sheets may be made after step ST6. Similarly for the other steps, in practice, all or part of each step may be performed before or after the order described with reference to FIG.

In step ST6, the second insulating layer 19B to the fourth insulating layer 19D before firing, and the first resistance heating element 15A and the second resistance heating element 15B (first conductive paste layer and second conductive paste layer) before firing. A laminated body (first laminated body) is obtained (see FIG. 8A). Specifically, for example, a first conductive paste layer to be the first resistance heating element 15A is arranged on the lower surface of the second insulating layer 19B or the upper surface of the third insulating layer 19C, and the lower surface of the third insulating layer 19C or the lower surface of the third insulating layer 19C. A second conductive paste layer to be a second resistance heating element 15B is arranged on the upper surface of the fourth insulating layer 19D, and the second insulating layer 19B to the fourth insulating layer 19D are laminated.

In step ST7, a hole 13h in which the connecting member 21 is arranged is formed in the first laminated body (second insulating layer 19B to fourth insulating layer 19D) before firing obtained in step ST6 (see FIG. 8A). ). The hole 13h is, for example, a through hole. The holes 13h may be formed for each ceramic green sheet before laminating.

In step ST8, as shown in FIG. 8B, the connecting member 21 is arranged in the hole 13h. The diameter of the hole 13h is slightly larger than the diameter of the connecting member 21, for example, and a gap is formed between the connecting member 21 and the inner surface of the hole 13h. Although not particularly shown, a conductive paste may be arranged in this gap. The main component of the conductive paste may be the same as or different from the main component of the resistance heating element 15 and / or the main component of the connecting conductor 25.

As illustrated in FIG. 8B, prior to step ST8, one of the openings at both ends of the hole 13h is the first insulating layer 19A or the fifth insulating layer 19E before firing (the latter in the illustrated example). ) May be blocked. Then, the connecting member 21 (and the conductive paste) may be arranged in the hole 13h from the other opening.

In step ST9, as shown in FIG. 8C, the unclosed openings at both ends of the hole 13h are closed by the remaining insulating layer before firing (first insulating layer 19A in the illustrated example). .. As a result, a second laminated body composed of the first insulating layer 19A to the fifth insulating layer 19E before firing is obtained. At this time, as shown by the arrow, pressure may be appropriately applied in the stacking direction.

In step ST10, as shown in FIG. 8D, the above-mentioned second laminated body (raw substrate 13) is fired. By firing, the substrate 13 shrinks. By this shrinkage, the substrate 13 may tighten the connecting member 21. Further, with this tightening, the resistance heating element 15 may be pressed against the portion of the side surface of the connecting conductor 25 that is exposed from the base material 23. As a result, the fixing strength between the substrate 13 and the connecting member 21 is improved, and the reliability of the connection between the connecting conductor 25 and the resistance heating element 15 is improved. Due to such tightening, the diameter of the hole 13h before firing is larger than the diameter of the connecting member 21 and larger than the diameter of the connecting member 21 due to shrinkage after firing (assuming that there is no connecting member 21). It may be made smaller.

Further, the base material 23 and the base material 13 are joined by firing. That is, a bonded body of the base material 23 and the base material 13 can be obtained. On the joint surface, both ceramic particles are in close contact with each other. When both materials are the same or the main components are the same, the boundary becomes ambiguous or disappears.

With firing, the substrate 13 and the conductive paste (resistance heating element 15 and the like) shrink in the thickness direction and the plane direction. On the other hand, since the connecting conductor 25 is a metal bulk material, such shrinkage does not occur. As a result, the amount of shrinkage of the substrate 13 (and the conductive paste) is reduced around the connecting conductor 25 (connecting member 21). More specifically, for example, the amount of shrinkage of the third insulating layer 19C in the thickness direction is reduced around the connecting member 21. As a result, the distance between the two resistance heating elements 15 facing each other with the third insulating layer 19C interposed therebetween becomes longer as they approach the connecting member 21. As a result, the inclined portion 15b is formed.

Although not particularly shown, it is also possible to arrange the base material 23 before firing on which the connecting conductor 25 is arranged in the hole 13h of the base material 13 before firing, and to fire both the base material 23 and the base material 13. .. Alternatively, the firing of the substrate 23 before the placement on the substrate 13 may be a temporary firing that does not sufficiently proceed with sintering.

As described above, in the present embodiment, the multilayer substrate (heater plate 9) includes the insulating substrate 13, the first conductor (first resistance heating element 15A), and the second conductor (second resistance heating element 15B). , With a connecting member 21. The substrate 13 has a first surface (upper surface 13a) and a second surface (lower surface 13b) on the back surface thereof. The first resistance heating element 15A is along the upper surface 13a in the substrate 13. The second resistance heating element 15B is along the upper surface 13a in the substrate 13 and on the lower surface 13b side with respect to the first resistance heating element 15A. The connecting member 21 connects the first resistance heating element 15A and the second resistance heating element 15B in the substrate 13. Further, the connecting member 21 has an insulating base material 23 and a connecting conductor 25. The connecting conductor 25 has a portion located in the base material 23 (substantially the whole in the present embodiment) and is connected to the first resistance heating element 15A and the second resistance heating element 15B (a portion connected to the first resistance heating element 15A and the second resistance heating element 15B). In this embodiment, it has a side surface).

Therefore, for example, the difference in thermal expansion between the connecting member 21 and the substrate 13 can be reduced as compared with the case where the entire connecting member 21 is made into a conductor. As a result, for example, the positional deviation between the connecting member 21 and the resistance heating element 15 can be reduced, and the reliability of the electrical connection can be improved. Further, for example, the thermal expansion amount of the connecting member 21 can be reduced and the thermal stress applied to the substrate 13 can be reduced as compared with the case where the entire connecting member 21 is made into a conductor. As a result, for example, the probability that the substrate 13 will be cracked can be reduced. On the other hand, the workability related to the production of the heater plate 9 is improved as compared with the case where only the connecting conductor 25 is arranged on the substrate 13 without the substrate 23. Further, for example, when an unintended stress is applied to the connecting member 21 due to shrinkage when the substrate 13 is fired, the connecting conductor 25 is protected by the substrate 23, so that the substrate 23 is not present. In comparison, the probability of disconnection is reduced.

Further, in the present embodiment, the base material 23 has a first columnar portion (in the embodiment, the entire base material 23) whose axial direction is from the upper surface 13a to the lower surface 13b. The connecting conductor 25 has a second columnar portion (in the embodiment, the entire connecting conductor 25) having the direction from the upper surface 13a to the lower surface 13b as the axial direction in the first columnar portion. A part of the side surface of the second columnar portion is connected to the first resistance heating element 15A and the second resistance heating element 15B.

In this case, for example, the reliability of the connection between the connecting conductor 25 and the resistance heating element 15 is improved. Specifically, for example, it is as follows. Unlike this embodiment, when connecting the end face of the connecting conductor and the end face of the resistance heating element 15, there is a manufacturing error in the vertical length of the connecting member 21, a manufacturing error in the distance between the two resistance heating elements 15, and the like. Must be small. However, in this embodiment, such a need is reduced. Further, for example, when the temperature of the heater plate 9 changes and a thermal expansion difference occurs between the connecting member 21 and the substrate 13, the connecting member 21 generally has a shape long in the thickness direction of the substrate 13. , The difference in thermal expansion tends to increase in the thickness direction of the substrate 13. As a result, the relative positions of the connecting member 21 and the resistance heating element 15 tend to shift in the thickness direction of the substrate 13. However, since the side surface of the connecting member 21 is connected to the resistance heating element 15, the connection between the two is maintained even if the above-mentioned positional deviation occurs.

Further, in the present embodiment, in the plan view of the upper surface 13a, the connecting conductor 25 has a shape in which a part on the opposite side to the center of the base material 23 is removed from the circular shape.

In this case, for example, in plan view, the outer edge of the connecting conductor 25 will have a relatively long straight line or curve facing the opposite side of the center of the substrate 23. Therefore, for example, it is easy to secure a contact area with the resistance heating element 15. Further, for example, by grinding the base material 23, it is possible to realize a connecting conductor 25 having a shape in which a part is removed from the circle. That is, as described above, it is easy to form a straight line or a curve that is advantageous for securing the contact area.

Further, in the present embodiment, in the plan view of the upper surface 13a, the connecting conductor 25 having a shape in which a part of the circle (referred to as the first circle) as described above is removed is the circumference of the first circle (referred to as the first circle). The curvature is smaller than that of the first arc 25a), and the arc (second arc 25b) with the center side of the base material 23 as the center of curvature is the boundary, and the first circle is opposite to the center of the base material 23. It has a shape with a part of the side removed.

In this case, for example, in a plan view, the outer edge of the connecting conductor 25 has a curve (second arc 25b) having a small curvature facing the side opposite to the center of the base material 23. Therefore, for example, in comparison with an embodiment in which the outer edge of the connecting conductor 25 is a circle having the same curvature as the first arc 25a on the center side of the base material 23 (such an embodiment may also be included in the technique according to the present disclosure). Therefore, it is easy to secure a contact area with the resistance heating element 15.

Further, in the present embodiment, the connecting member 21 has a plurality of connecting conductors 25.

In this case, for example, it is easy to secure a contact area between the connecting conductor 25 and the resistance heating element 15. Further, even if some of the connecting conductors 25 are disconnected due to unintended stress, the other connecting conductors 25 ensure continuity. Therefore, the electrical reliability of the two resistance heating elements 15 is improved.

Further, in the present embodiment, the connecting member 21 has four or more connecting conductors 25 on the same circumference in a plan view of the upper surface 13a.

In this case, since a relatively large number of connecting conductors 25 are provided, the above effect is improved. The fact that the connecting conductors 25 are located on the same circumference means that the connecting conductors 25 are arranged along the outer edge of the circular base material 23 in a plan view. In this case, for example, it is easy to expose a plurality of connecting conductors 25 or make them have the same shape by grinding the side surface of the columnar base material 23.

Further, in the present embodiment, four or more connecting conductors 25 are arranged on the same circumference at equal pitches.

In this case, for example, the influence of the residual stress and / or the thermal stress generated between the connecting conductor 25 and the base material 23 can be easily equalized in a plan view. As a result, for example, it is possible to reduce the probability that the local stress will increase. Further, even if an unintended deformation occurs in a specific direction in the XY plane and the connecting conductor 25 and the resistance heating element 15 connected to each other in the above specific direction are disconnected, other parts in the XY plane are obtained. It is expected that a connection will be maintained between the connecting conductor 25 and the resistance heating element 15 which are connected to each other in the direction.

Further, in the present embodiment, the material of the substrate 13 is ceramic, and the material of the substrate 23 is a ceramic having the same main component as the material of the substrate 13.

In this case, for example, since the substrate 13 and the substrate 23 are bonded to each other, the bonding strength between the substrate 13 and the connecting member 21 is improved. Further, since the main components are common, the bonding strength is further improved and the difference in thermal expansion between the two is reduced.

Further, in the present embodiment, the first resistance heating element 15A is a layered conductor and has a main portion 15a and an inclined portion 15b. The main portion 15a is along the upper surface 13a. The inclined portion 15b is inclined with respect to the main portion 15a so that the side close to the connecting conductor 25 is located on the upper surface 13a side or the lower surface 13b side (in the present embodiment, the upper surface 13a side) and is connected to the connecting conductor 25. There is.

In this case, for example, when the first resistance heating element 15A is deformed due to the difference in thermal expansion between the connecting conductor 25 and the base 13, the first resistance heating element 15A is tilted from before the deformation, so that it is caused by the deformation. Changes in heat distribution are mitigated. The fact that the inclined portion 15b is formed can be one of the evidences that the connecting conductor 25 is manufactured by including the metal bulk material.

Further, in the present embodiment, in the first resistance heating element 15A, the inclined portion 15b is inclined with respect to the main portion 15a so that the side close to the connecting conductor 25 is located on the upper surface 13a side. In the second resistance heating element 15B, the inclined portion 15b is inclined with respect to the main portion 15a so that the side closer to the connecting conductor 25 is located on the lower surface 13b side.

In this case, for example, even if the two resistance heating elements 15 are deformed in a direction in which the two resistance heating elements 15 are separated from each other due to the thermal expansion of the connecting conductor 25 in the thickness direction of the substrate 13, the resistance heating elements 15 are inclined from before the deformation. , The change in heat distribution caused by deformation is mitigated. Since the two resistance heating elements 15 are highly likely to be deformed in the direction of being separated from each other in the vicinity of the connecting conductor 25, the probability that the change in heat distribution can be alleviated is also high.

Further, in the present embodiment, the connecting conductor 25 extends from the lower surface 13b side of the first resistance heating element 15A to the upper surface 13a side of the first resistance heating element 15A, so that the connecting conductor 25 is located on the side surface of the connecting conductor 25. It is connected to a 1-resistance heating element 15A. The end portion of the connecting conductor 25 on the upper surface 13a side is located in the substrate 13 and is not connected to another conductor through which a current flows.

In this case, the connecting conductor 25 extends toward the upper surface 13a from the first resistance heating element 15A in order to connect its side surface to the first resistance heating element 15A, and is connected to another conductor. It does not extend toward the upper surface 13a from the first resistance heating element 15A. The effect of connecting on the side is as already mentioned. Further, for example, the upper end of the connecting conductor 25 is located above the first resistance heating element 15A, so that the upper end is separated from the first resistance heating element 15A. On the other hand, the stress in the Z direction caused by the vertical expansion of the connecting conductor 25 is easily transmitted from the upper end of the connecting conductor 25 to the substrate 13. Therefore, the position where the stress in the Z direction is applied to the substrate 13 is separated from the resistance heating element 15, and the possibility that the substrate 13 or the like is unintentionally deformed in the vicinity of the resistance heating element 15 is reduced.

From another point of view, in the present embodiment, the multilayer substrate (heater plate 9) includes an insulating substrate 13, a first conductor (first resistance heating element 15A), and a second conductor (second resistance heating element). It has 15B) and a connecting conductor 25. The substrate 13 has a first surface (upper surface 13a) and a second surface (lower surface 13b) on the back surface thereof. The first resistance heating element 15A is along the upper surface 13a in the substrate 13. The second resistance heating element 15B is along the upper surface 13a in the substrate 13 and on the lower surface 13b side with respect to the first resistance heating element 15A. The connecting conductor 25 connects the first resistance heating element 15A and the second resistance heating element 15B in the substrate 13. In a plan view of the upper surface 13a, the outer edge of the connecting conductor 25 has a first arc 25a and a second arc 25b. The second arc 25b has a smaller curvature than the first arc 25a and is connected to the first resistance heating element 15A.

Therefore, for example, the volume of the connecting conductor 25 can be reduced while increasing the contact area between the connecting conductor 25 and the resistance heating element 15. By reducing the volume of the connecting conductor 25, for example, the thermal stress applied to the substrate 13 due to the thermal expansion of the connecting conductor 25 can be reduced, and the probability that the substrate 13 will be cracked can be reduced. It should be noted that the fact that the connecting conductor 25 has the first arc 25a and the second arc 25b is the present embodiment when the base material 23 and the base material 13 are finally integrated and indistinguishable. It can be one of the proofs that the manufacturing method of.

From yet another point of view, in the present embodiment, the multilayer substrate (heater plate 9) includes an insulating substrate 13, a first conductor (first resistance heating element 15A), and a second conductor (second resistance heating element 15B). ) And the connecting conductor 25. The substrate 13 has a first surface (upper surface 13a) and a second surface (lower surface 13b) on the back surface thereof. The first resistance heating element 15A is along the upper surface 13a in the substrate 13. The second resistance heating element 15B is along the upper surface 13a in the substrate 13 and on the lower surface 13b side with respect to the first resistance heating element 15A. The connecting conductor 25 connects the first resistance heating element 15A and the second resistance heating element 15B in the substrate 13. The first resistance heating element 15A has a long portion extending along the upper surface 13a (the reference numeral is omitted because it is the entire first resistance heating element 15A in this embodiment). In a plan view of the upper surface 13a, a plurality of connecting conductors 25 are located on the same circumference having a diameter equal to or less than the width of the long portion of the first resistance heating element 15A and are connected to the long portion.

Therefore, by providing the plurality of connecting conductors 25, it is easy to increase the contact area between the connecting conductors 25 and the resistance heating element 15 with respect to the volume. As a result, for example, the stress applied to the substrate 13 due to the thermal expansion of the connecting conductor 25 can be reduced while ensuring the reliability of conduction. It is also expected that the thermal stress applied to the substrate 13 will be dispersed by dispersing the plurality of connecting conductors 25. It should be noted that the fact that the plurality of connecting conductors 25 are located on the same circumference within the width of the resistance heating element 15 means that the base material 23 and the base material 13 are finally integrated and indistinguishable. It can be one of the evidences that the manufacturing method of this embodiment has been carried out.

In this embodiment, the multilayer board (heater plate 9) as described above is applied to the heater system 101. The heater system 101 includes a heater plate 9 and a power supply unit 3 electrically connected to a first resistance heating element 15A and a second resistance heating element 15B.

In this case, for example, since the calorific value is defined by the electric power supplied to the resistance heating element 15, the reliability of the connection of the connecting member 21 is improved, and the route from the power supply unit 3 to the resistance heating element 15 is improved. By stabilizing the resistance value, the heating element is stabilized.

Further, in the present embodiment, the method for manufacturing the heater plate 9 includes a step of manufacturing the connecting member 21 (ST1 to ST4) and a step of firing the substrate 13 made of ceramics before firing (ST10). ,have. In the firing step (ST10), the connecting member 21 is arranged inside the substrate 13 before firing. The step of producing the connecting member 21 includes a molding step (ST1), an insertion step (ST2), and a firing step (ST3). In the molding step, the ceramic raw material is used to form a molded body to be the base material 23. In the insertion step, the connecting conductor 25 is inserted through the molded body (23). In the firing step, the molded body (23) through which the connecting conductor 25 is inserted is fired.

Therefore, for example, the connecting conductor 25 can be held by shrinking the base material 23 during sintering. Further, for example, the base material 23 made of ceramic and the base material 13 made of ceramic can be directly bonded, and the bonding strength between the two can be improved. Further, the difference in thermal expansion between the connecting member 21 and the substrate 13 can be easily reduced.

[Modification example]
A modified example of the configuration of the connecting member 21 and its surroundings will be described below. In the following description, basically, only the differences from the embodiments will be described. Therefore, the matters not particularly mentioned may be the same as those in the embodiment. Further, with respect to the configuration corresponding to the configuration of the embodiment, even if there is a difference from the configuration of the embodiment, the same reference numerals as those assigned to the configurations of the embodiment may be added for convenience.

(First modification)
FIG. 9 (a) is a diagram corresponding to FIG. 3 (b) showing the configuration according to the first modification.

In this modification, a gap 31 is formed between the connecting member 21 and the substrate 13. The void 31 is sealed, for example. The void 31 is in a vacuum state or a gas is present. The vacuum state is actually a state of pressure lower than atmospheric pressure. The gas is, for example, air or an inert gas (eg, nitrogen).

Specifically, the gap 31 is located on at least one of the upper surface 13a side and the lower surface 13b side (both in the illustrated example) with respect to the connecting member 21. The shape and size of the gap 31 may be appropriately set. Such a gap 31 can be formed, for example, by shortening the length of the metal bulk material (connecting conductor 25) with respect to the length of the hole 13h in the Z direction.

When the void 31 is formed in this way, for example, the probability that a large stress is applied to the substrate 13 due to the thermal expansion of the connecting member 21 (connecting conductor 25) is reduced, and the probability that a crack is generated in the substrate 13 is reduced. Will be done. In particular, when the gap 31 is located on at least one of the upper surface 13a side and the lower surface 13b side of the connecting member 21, the connecting member 21 tends to have a large amount of thermal expansion in the Z direction as described above. The effect of is improved.

(Second modification)
FIG. 9B is a side view showing a part of the upper end side of the connecting member 21 according to the second modification.

As mentioned in the description of the embodiment, the end portion (upper end or lower end) of the connecting conductor 25 may protrude from the end surface (upper surface or lower surface) of the base material 23. It should be noted that this protruding portion may be caused by the fact that when the end faces of the base material 23 and the connecting conductor 25 are ground (step ST4), the base material 23 is easier to grind than the connecting conductor 25. do not have.

When such a protruding portion is formed, the resistance heating element 15 may be connected to a portion of the side surface of the connecting conductor 25 that is exposed from the side surface of the base material 23, as in the embodiment. However, unlike the embodiment, it may be connected to the above-mentioned protruding portion. In the latter case, the resistance heating element 15 may be connected to the end surface of the protruding portion of the connecting conductor 25, or may be connected to the side surface. Although not particularly shown, when the protruding portion of the connecting conductor 25 and the resistance heating element 15 are connected, the connecting conductor 25 may not be exposed from the side surface of the base material 23. It is also possible to connect the end face of the connecting conductor 25 and the resistance heating element 15 when the end face of the connecting conductor 25 and the end face of the base material 23 are flush with each other.

(Third modification example)
FIG. 10 (a) is a diagram corresponding to FIG. 3 (b) showing the configuration according to the third modification.

However, in this figure, the distinction between the base material 23 and the connecting conductor 25 in the connecting member 221 is not shown. The base material 23 may be regarded as having a shape similar to the shape of the connecting member 221 shown in the figure. The connecting conductor 25 may be, for example, a columnar shape exposed from the side surface of the base material 23, as in the embodiment. The same applies to the fourth modification (FIG. 10 (b)) described later.

In this modification, the connecting member 221 is formed in a trapezoidal shape in a cross-sectional view. That is, the side surface of the connecting member 221 constitutes a trapezoidal leg, and the upper surface and the lower surface of the connecting member 221 form the upper bottom and the lower bottom of the trapezoid. In the illustrated example, the upper bottom (relatively short bottom) is located on the upper surface 13a side, and the lower bottom is located on the lower surface 13b side. good. Then, the connecting member 221 (or the connecting conductor 25) is connected to the resistance heating element 15 in the trapezoidal leg. Although not particularly shown, the connecting conductor 25 may be formed in a trapezoidal columnar shape in a cross-sectional view, or a conductor having the same shape as that of the embodiment is inclined along the trapezoidal leg of the connecting member 221. It may be arranged in a row.

From another aspect, the connecting member 221 (hole 13h) has an inclined surface inclined with respect to the thickness direction of the substrate 13. The connecting member 221 is connected to the resistance heating element 15 on the inclined surface. The inclination angle of the inclined surface may be appropriately set. In the illustrated example, both of the two resistance heating elements 15 are connected to the connecting member 221 (connecting conductor 25) on an inclined surface. Unlike the illustrated example, only one resistance heating element 15 may be connected to the connecting member 221 on an inclined surface.

The hole 13h has the shape shown in the figure, for example, when the inner surface thereof is in close contact with the outer surface of the connecting member 221 during shrinkage due to sintering. However, the hole 13h may have a shape shown in the figure or a shape similar thereto before the conductor to be the connecting member 221 is arranged.

In this modification, for example, the force of the substrate 13 that contracts in the plane direction (XY plane) due to sintering can be directed toward the upper bottom side along the trapezoidal legs. As a result, the inclined portion 15b of the resistance heating element 15 tends to be inclined toward the upper bottom side. That is, it becomes easy to control the inclination direction of the inclined portion 15b. Further, for example, since the resistance heating element 15 moves toward the connecting member 21 side in the plane direction and moves toward the upper bottom side along the trapezoidal leg, the contact area with the trapezoidal leg increases as shown in the figure. This improves the reliability of the connection. Further, for example, when the connecting member 221 is thermally expanded in the Z direction, the force is easily released in the XY direction. This effect also occurs when the connecting member 221 is composed of only the conductive paste.

(Fourth modification)
FIG. 10B is a diagram similar to FIG. 10A showing the configuration according to the fourth modification.

As can be understood from the above description of the third modification, the effect described in the third modification is not only that the connecting member has a trapezoidal shape in cross-sectional view, but also that the connecting member is connected to the resistance heating element 15. It is played in various embodiments that have an inclined surface in position. In the fourth modification, the connecting member 321 has a hexagonal shape instead of a trapezoidal shape. The inclined portions of the two resistance heating elements 15 are inclined in opposite directions to each other, unlike the third modification.

In the above embodiments and modifications, the heater plate 9 is an example of a multilayer substrate. One of the upper surface 13a and the lower surface 13b is an example of the first surface, and the other is an example of the second surface. One of the first resistance heating element 15A and the second resistance heating element 15B is an example of the first conductor, and the other is an example of the second conductor. The entire base material 23 is an example of the columnar portion of the base material. The entire connecting conductor 25 is an example of a columnar portion of the connecting conductor. In one of the first resistance heating element 15A and the second resistance heating element 15B, the main portion 15a and the inclined portion 15b are examples of the first main portion and the first inclined portion. On the other side of the first resistance heating element 15A and the second resistance heating element 15B, the main portion 15a and the inclined portion 15b are examples of the second main portion and the second inclined portion. The entire first resistance heating element 15A or the entire second resistance heating element 15B is an example of a long portion of the first conductor. The base material 23 before firing is an example of a molded product.

The technique according to the present disclosure is not limited to the above embodiments and modifications, and may be implemented in various embodiments.

The above-described embodiments and various modifications may be combined as appropriate. For example, the void 31 shown in FIG. 9 (a) may be combined with the shapes of FIGS. 10 (a) and 10 (b).

In the embodiment, a heater plate having a heating function is taken as an example as a multilayer substrate. However, the multilayer board may have other functions. For example, the multilayer substrate may be an electrostatic chuck or an electrode member for plasma generation, or may function as a combination of two or more of these and a heater. Further, the multilayer board may be a circuit board.

From another point of view, the first conductor and the second conductor are resistance heating elements for heating in the embodiment, but may be conductors for other purposes, for example, an electrode for an electrostatic chuck or plasma generation. It may be an electrode for. The multilayer board may have one of these electrodes and a resistance heating element, or a combination of two or more. The first conductor and the second conductor may be, for example, conductors having a shape that can be said to extend (face upward) along the upper surface of the substrate (13) as a whole. Further, for example, when assuming the smallest circle or rectangle surrounding the entire first conductor or the entire second conductor in a plan view, the area surrounded by the circle or rectangle is 60% or more or 80% of the upper surface of the substrate. It may occupy the above.

Further, the first conductor and the second conductor may not be conductors that directly carry out the function of the multilayer board such as a resistance heating element or electrodes, and may be wiring, for example. Therefore, for example, the connecting conductor may connect the resistance heating element and the wiring composed of the layered conductor located on the lower surface side of the resistance heating element. In this case, the heater does not have two or more layers of resistance heating elements, but may have only one layer of resistance heating elements.

In the embodiment, the substrate 13 of the heater plate 9 is made by laminating a plurality of ceramic green sheets. However, the substrate 13 may be manufactured by hot pressing to pressurize and heat the ceramic raw material in the mold.

1 ... heater, 13 ... substrate, 13a ... top surface (first surface or second surface), 13b ... bottom surface (second surface or first surface), 15A ... first resistance heating element (first conductor or second conductor) , 15B ... second resistance heating element (second conductor or first conductor), 21 ... connecting member, 23 ... base material, 25 ... connecting conductor.

Claims (13)

An insulating substrate having a first surface and a second surface on the back surface thereof,
With the first conductor along the first surface in the substrate,
A second conductor in the substrate and along the first surface on the second surface side with respect to the first conductor.
A connecting member connecting the first conductor and the second conductor in the substrate,
Have and
The connecting member is
Insulating base material and
It has a portion located in the substrate and a connecting conductor having a portion connected to the first conductor and the second conductor .
The base material has a first columnar portion whose axial direction is from the first surface to the second surface.
The connecting conductor has a second columnar portion in the first columnar portion whose axial direction is from the first surface to the second surface.
A part of the side surface of the second columnar portion is connected to the first conductor and the second conductor.
In the plan view of the first surface, the connecting conductor has a shape in which a part on the opposite side to the center of the base material is removed from the circle.
Multi-layer board. In the plan view of the first surface, the connecting conductor has a smaller curvature than the circumference of the circle, and is opposite to the center from the circle with an arc having the center side of the base material as the center of curvature as a boundary. The multilayer substrate according to claim 1 , which has a shape in which a part of the side is removed. An insulating substrate having a first surface and a second surface on the back surface thereof,
With the first conductor along the first surface in the substrate,
A second conductor in the substrate and along the first surface on the second surface side with respect to the first conductor.
A connecting member connecting the first conductor and the second conductor in the substrate,
Have and
The connecting member is
Insulating base material and
It has a portion located in the substrate and a connecting conductor having a portion connected to the first conductor and the second conductor.
The substrate has voids on at least one of the first surface side and the second surface side of the connecting member.
Multi-layer board. An insulating substrate having a first surface and a second surface on the back surface thereof,
With the first conductor along the first surface in the substrate,
A second conductor in the substrate and along the first surface on the second surface side with respect to the first conductor.
A connecting member connecting the first conductor and the second conductor in the substrate,
Have and
The connecting member is
Insulating base material and
It has a portion located in the substrate and a connecting conductor having a portion connected to the first conductor and the second conductor.
The first conductor is
The first main part along the first surface and
A first inclined portion that is inclined with respect to the first main portion and is connected to the connecting conductor so that the side close to the connecting conductor is located on the first surface side or the second surface side. Have
Multi-layer board. The second conductor is
The second main part along the first surface and
It has a second inclined portion that is inclined with respect to the second main portion and is connected to the connecting conductor so that the side close to the connecting conductor is located on the first surface side or the second surface side. And
The first inclined portion is inclined with respect to the first main portion so that the side closer to the connecting conductor is located on the first surface side.
The multilayer substrate according to claim 4 , wherein the second inclined portion is inclined with respect to the second main portion so that the side close to the connecting conductor is located on the second surface side. The multilayer substrate according to any one of claims 1 to 5 , wherein the connecting member has a plurality of the connecting conductors. The multilayer substrate according to claim 6 , wherein the connecting member has four or more connecting conductors on the same circumference in a plan view of the first surface. The multilayer board according to claim 7 , wherein the four or more connecting conductors are arranged on the same circumference at equal pitches. The material of the substrate is ceramic,
The multilayer substrate according to any one of claims 1 to 8 , wherein the material of the base material is a ceramic having the same main component as the material of the base material. The connecting conductor is connected to the first conductor on the side surface of the connecting conductor by extending from the second surface side of the first conductor to the first surface side of the first conductor. The end of the connecting conductor on the first surface side is located in the substrate, and the end is not connected to another conductor through which a current flows. Any one of claims 1 to 9 . The multilayer board described in. An insulating substrate having a first surface and a second surface on the back surface thereof,
With the first conductor along the first surface in the substrate,
A second conductor in the substrate and along the first surface on the second surface side with respect to the first conductor.
A connecting conductor connecting the first conductor and the second conductor in the substrate,
Have and
In the plan view of the first surface, the outer edge of the connecting conductor is
The first arc and
A multilayer substrate having a second arc having a curvature smaller than that of the first arc and being connected to the first conductor. The first conductor has a long portion extending along the first surface.
In the plan view of the first surface, a plurality of the connecting conductors are located on the same circumference having a diameter equal to or less than the width of the long portion and are connected to the long portion.
The multilayer board according to claim 11 . The multilayer board according to any one of claims 1 to 12 and the multilayer board.
A power supply unit electrically connected to the first conductor and the second conductor,
Have and
A heater system in which at least one of the first conductor and the second conductor is a resistance heating element.

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