Ceramic structure

Abstract

A ceramic structure according to the present disclosure comprises: a substrate made of ceramics; and a wiring layer located inside the substrate. The substrate includes: a first opening located on the surface; a first cavity connected to the first opening and the wiring layer; and a rod-shaped terminal at least a section of which is located in the first cavity and which has lateral surfaces and end surfaces. The wiring layer includes: a first surface; a second surface located opposite the first surface; and a third surface connecting the first surface and the second surface. In the first cavity, the terminal faces the third surface of the wiring layer. In the first cavity, the length direction of the terminal is substantially parallel to the first surface. The terminal and the wiring layer are electrically connected.

Description

Ceramic Structure

[0001] The present disclosure relates to ceramic structures.

[0002] Conventionally, various ceramic structures have been used, each having as its constituent elements a ceramic substrate and a wiring layer disposed inside the substrate. For example, Patent Document 1 discloses a rod-shaped ceramic heater having a heating resistor therein. These ceramic heaters have connection terminals provided on the side surfaces of the rod-shaped ceramic substrate.

[0003] JP 2017-228368 A

[0004] The ceramic structure of the present disclosure includes a ceramic substrate and a wiring layer located inside the substrate. The substrate has a first opening located on its surface, a first cavity connecting the first opening and the wiring layer, and a rod-shaped terminal having a side surface and an end surface, at least a portion of which is located within the first cavity. The wiring layer has a first surface, a second surface opposite the first surface, and a third surface connecting the first surface and the second surface. The terminal faces the third surface of the wiring layer within the first cavity, and the longitudinal direction of the terminal is approximately parallel to the first surface within the first cavity. The terminal and the wiring layer are electrically connected.

[0005] FIG. 1 is a perspective view of a substrate in a ceramic structure according to a first embodiment. FIG. 2 is a cross-sectional view of a substrate in a ceramic structure according to a first embodiment. FIG. 3 is a cross-sectional view of a ceramic structure according to a first embodiment. FIG. 4 is an enlarged cross-sectional view of a main portion of a ceramic structure according to a first embodiment. FIG. 5 is an enlarged cross-sectional view of a main portion of a ceramic structure according to a first embodiment. FIG. 6 is a cross-sectional view of a ceramic structure according to a first embodiment. FIG. 7 is a cross-sectional view of a ceramic structure according to a second embodiment. FIG. 8 is a cross-sectional view of a ceramic structure according to a third embodiment. FIG. 9 is a cross-sectional view of a ceramic structure according to a fourth embodiment. FIG. 10 is a cross-sectional view of a ceramic structure according to a fifth embodiment.

[0006] Hereinafter, modes for carrying out the ceramic structure according to the present disclosure (hereinafter referred to as "embodiments") will be described in detail with reference to the drawings. Note that the present disclosure is not limited to these embodiments. Furthermore, the respective embodiments can be appropriately combined within a range that does not cause contradictions in the processing content. Furthermore, the same components in the following embodiments will be given the same reference numerals, and redundant explanations will be omitted.

[0007] Furthermore, in the following embodiments, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not necessarily mean "constant," "orthogonal," "perpendicular," or "parallel" in the strict sense. In other words, the above expressions allow for deviations due to, for example, manufacturing precision, installation precision, etc.

[0008] The present disclosure relates to ceramic structures with improved electrical connection terminal placement.

[0009] First Embodiment A ceramic structure 100 according to a first embodiment may have a rod-shaped substrate 1, for example, as shown in FIGS. 1 to 3. Cross sections taken along the dashed line connecting L1 and L2 shown in FIG. 1 are shown in FIGS. 2 and 3. Cross sections taken along the circular dashed line indicated by L3 in FIG. 1 are shown in FIGS. 4 and 5. The substrate 1 may be plate-shaped or cylindrical. The substrate 1 may have a total length of about 10 to 100 mm and a width of about 5 to 50 mm, for example.

[0010] The base 1 is made of ceramics. For example, the base 1 may be made of an alumina sintered body, a zirconia sintered body, a silicon nitride sintered body, or an aluminum nitride sintered body. As shown in Fig. 2, the base 1 may have a wiring layer 3 therein. The material of the wiring layer 3 may be, for example, copper, silver, tungsten, molybdenum, platinum, or any other metal that has been conventionally used for wiring layers 3.

[0011] The wiring layer 3 may have a linear shape, for example, in which the width is greater than the thickness. A linear shape may be a shape that extends in a certain direction with a length equal to or greater than the width. As shown in Figure 2, the wiring layer 3 may have, for example, a first surface 3a and a second surface 3b located opposite the first surface 3a. In Figure 2, the surface connecting the first surface 3a and the second surface 3b is illustrated as a third surface 3c.

[0012] The base 1 has a first opening 9 located on the surface and a first cavity 11 connected to the first opening 9. As shown in FIG. 2 , the base 1 may have a first end face 13a and a second end face 13b located opposite the first end face 13a. In the first embodiment, the first opening 9 may be located at the first end face 13a. The wiring layer 3 is exposed on the inner wall surface 11a of the first cavity 11. As shown in FIG. 3 , at least a portion of a terminal 15 is located in the first cavity 11. The terminal 15 may be a rod-shaped member having a side surface and an end face. Specifically, the terminal 15 may have a third end face 15a located inside the first cavity 11, a fourth end face 15b located opposite the third end face 15a, and a side face 15c connecting the third end face 15a and the fourth end face 15b. The terminal 15 may be a metal wire or a so-called terminal for attaching a metal wire.

[0013] The base 1 may have a second opening 5a located on the surface and a second cavity 7 connected to the second opening 5a. In the first embodiment, the second opening 5a may be located on the first end surface 13a. In the examples of FIGS. 1 to 3, the second cavity 7 is a through-hole. Specifically, the base 1 may have a third opening 5b located opposite the second opening 5a. The third opening 5b may be located on the second end surface 13b. The second cavity 7 may be connected to the second opening 5a and the third opening 5b. In this way, the base 1 may have the third opening 5b connected to the second cavity 7. However, the second cavity 7 may have a bottom surface.

[0014] The terminal 15 and the third surface 3c of the wiring layer 3 face each other inside the first cavity 11. Specifically, the side surface 15c of the terminal 15 and the third surface 3c of the wiring layer 3 may face each other inside the first cavity 11. The terminal 15 and the wiring layer 3 may be electrically connected, for example, via a brazing material (not shown). The terminal 15 and the wiring layer 3 may also be electrically connected, for example, via a conductive adhesive (not shown).

[0015] The wiring layer 3 may have an end portion that is exposed on the surface of the ceramic structure 100 and is not electrically connected to the terminal 15. If the wiring layer 3 has such an end portion, the ceramic structure 100 can be used as a wiring member for supplying power.

[0016] The base 1 may have a plurality of first openings 9 on the first end surface 13 a. The base 1 may also have a first opening 9 on the second end surface 13 b. For example, when the base 1 has two first openings 9, the wiring layer 3 exposed in two first cavities 11 connected to the two first openings 9 may be electrically connected.

[0017] 2 and 3 show an example in which, in a cross section, a plurality of wiring layers 3 are aligned in the longitudinal direction connecting the first end face 13a and the second end face 13b of the base 1. These wiring layers 3 may be electrically independent. Alternatively, all of the wiring layers 3 may be electrically connected. For example, in the example shown in FIGS. 2 and 3, the wiring layers 3 may be arranged in a spiral shape inside the base 1. In this way, the wiring layers 3 may surround the second cavity 7.

[0018] As shown in FIGS. 4 and 5 , the wiring layer 3 may be arranged so as to intersect with the longitudinal direction of the base 1. In the example shown in FIG. 4 , the wiring layer 3 is exposed on the inner wall surface of the first cavity 11. In the example shown in FIG. 4 , the wiring layer 3 is not exposed on the bottom surface of the first cavity 11. In contrast, in the example shown in FIG. 5 , the wiring layer 3 is exposed on both the side and bottom surfaces of the first cavity 11. When the wiring layer 3 is exposed on both the side and bottom surfaces of the first cavity 11, as in the example shown in FIG. 5 , the exposed area of ​​the wiring layer 3 is larger, thereby improving the connection reliability between the wiring layer 3 and the terminal 15. Specifically, in this case, the third surface 3c of the wiring layer 3 faces the third end surface 15a and the side surface 15c of the terminal 15, thereby increasing the contact area between the wiring layer 3 and the terminal 15 and improving the connection reliability between them. In addition, the resistance value in the connection between the wiring layer 3 and the terminal 15 is reduced.

[0019] The wiring layer 3 may be a heating resistor. In other words, the ceramic structure 100 of the present disclosure may be a heater. In such a case, it is possible to heat a fluid located inside the second cavity 7 located inside the base 1. It is also possible to heat the outside of the base 1. Furthermore, the wiring layer 3 may have, for example, wiring layers 3 made of two different metals, and the wiring layers 3 made of the different metals may be connected inside the base 1 to function as a so-called thermocouple. In this configuration, it is possible to measure the temperature of a substance located inside the second cavity 7 located inside the base 1.

[0020] The ceramic structure 100 of the present disclosure may be a sensor holder. For example, as shown in FIG. 6 , the ceramic structure 100 may have a sensor 16 mounted on the surface of the base 1. Specifically, the sensor 16 may be located, for example, on the second end surface 13 b of the base 1. The sensor 16 may be, for example, a temperature sensor. In the example of FIG. 6 , an end of the wiring layer 3 may be exposed at the second end surface 13 b of the base 1. In such a case, the end of the wiring layer 3 and the electrode portion of the sensor 16 can be electrically connected. This allows the wiring layer 3 to serve as a power supply portion for the sensor 16.

[0021] In the ceramic structure 100 of the present disclosure, the wiring layer 3 can be protected by the ceramic substrate 1. Therefore, short circuits are less likely to occur in the wiring layer 3. Furthermore, by protecting the wiring layer 3 from liquids and atmospheric gases, deterioration of the wiring layer 3 can be reduced.

[0022] (Manufacturing Method) The ceramic structure of the present disclosure can be manufactured, for example, by the method described below.

[0023] First, a cylindrical ceramic compact is prepared. The ceramic compact may contain, for example, alumina powder and a binder. Such a ceramic compact can be produced by a conventional extrusion molding method.

[0024] Next, a ceramic sheet is prepared. This ceramic sheet may also contain alumina powder and a binder. One surface of the ceramic sheet is then printed with, for example, a commercially available metal conductor paste to form a wiring pattern that will become a wiring layer after firing.

[0025] Then, the sheet-like ceramic molded body on which the wiring pattern is formed is wrapped around the surface of the cylindrical ceramic molded body, preferably so that the wiring pattern is in contact with the surface of the cylindrical ceramic molded body.

[0026] Next, a hole is formed in the end surface of the cylindrical ceramic compact to expose the wiring pattern. After degreasing and firing, a brazing material and a rod-shaped terminal are inserted into the first cavity formed in the end surface of the obtained substrate, and the substrate is heated to a temperature at which the brazing material melts, thereby producing the ceramic structure of the present disclosure.

[0027] Second Embodiment Next, the configuration of a ceramic structure 100 according to a second embodiment will be described with reference to FIG. 7 . FIG. 7 is a cross-sectional view of the ceramic structure 100 according to the second embodiment. In the first embodiment, an example was described in which the first opening 9 was located on the first end face 13 a of the base 1. On the other hand, in the second embodiment, as shown in FIG. 7 , the first opening 9 may be located on the side face 13 c of the base 1. The side face 13 c here refers to a face that connects the first end face 13 a and the second end face 13 b of the base 1. The position of the first opening 9 on the side face 13 c is not particularly limited. However, for example, if the first opening 9 is located on the side face 13 c on the first end face 13 a side of the base 1, it is easy to attach a terminal 15 to the ceramic structure 100.

[0028] In the second embodiment, the base 1 may have a wiring layer 3 arranged along the longitudinal direction connecting the first end face 13 a and the second end face 13 b, and a wiring layer 3 arranged so as to intersect with the longitudinal direction of the base 1. In such a case, the wiring layer 3 arranged along the longitudinal direction of the base 1 may surround the second cavity 7. Furthermore, the wiring layer 3 arranged so as to intersect with the longitudinal direction of the base 1 may be exposed on the inner wall surface of the first cavity 11.

[0029] The base 1 according to the second embodiment may be manufactured using injection molding as follows. First, a substantially cylindrical ceramic molded body having, for example, a T-shape in side view is produced by injection molding. Next, a desired wiring pattern is injection molded onto the surface of the ceramic molded body. Next, a ceramic portion covering the wiring pattern is injection molded. The structure thus obtained is subjected to a degreasing process and a firing process, and holes are formed in the surface to expose the wiring pattern, thereby producing the base 1.

[0030] Third Embodiment Next, the configuration of a ceramic structure 100 according to a third embodiment will be described with reference to Fig. 8. Fig. 8 is a cross-sectional view of the ceramic structure 100 according to the third embodiment. As shown in Fig. 8, in the third embodiment, the substrate 1 may have a main body portion 17 and a flange portion 19 protruding from the main body portion 17.

[0031] The main body portion 17 may have a cylindrical shape extending from the first end face 13a toward the second end face 13b. In other words, the main body portion 17 may be a cylindrical portion of the base 1 extending from the first end face 13a toward the second end face 13b. The flange portion 19 may protrude radially outward from the outer periphery of the main body portion 17. The base 1 according to the third embodiment may be made from a single ceramic molded body. In other words, in the third embodiment, the ceramics constituting the main body portion 17 and the flange portion 19 may have the same composition. The base 1 having the flange portion 19 may be manufactured by injection molding, similar to the base 1 according to the second embodiment. Specifically, after injection molding a ceramic molded body having a flange portion, the ceramic body may be degreased and fired.

[0032] If the base 1 has the flange 19, the ceramic structure 100 can be easily attached to another member. Specifically, the ceramic structure 100 can be easily attached to another member by fitting the flange 19 into a recess or the like provided in the other member.

[0033] The flange 19 may protrude from the end of the main body 17. Specifically, the flange 19 may protrude, for example, from the end of the main body 17 on the first end face 13 a side. With this configuration, when another member is located on the first end face 13 a side of the base 1, the flange 19 can be easily fitted into a recess or the like of the other member. Therefore, the attachability of the ceramic structure 100 to the other member can be further improved.

[0034] In addition, when the base 1 has a flange 19, the first opening 9 may open on the surface of the flange 19. For example, the first opening 9 may open on the first end face 13 a of the flange 19. Alternatively, the first opening 9 may open on the end face of the flange 19 located opposite to the first end face 13 a. Alternatively, the first opening 9 may open on the side face 13 c of the flange 19.

[0035] Fourth Embodiment Next, the configuration of a ceramic structure 100 according to a fourth embodiment will be described with reference to Fig. 9. Fig. 9 is a cross-sectional view of the ceramic structure 100 according to the fourth embodiment. The ceramic structure 100 according to the fourth embodiment may have a low-resistance member 21 located on the surface of the base 1 and having a resistance value lower than that of the base 1. Specifically, the resistance value of the base 1 is, for example, 1 x 10 １２ The resistance value of the low resistance member 21 may be, for example, 1×10 ９ It may be Ω or less.

[0036] 9, the low resistance member 21 may be positioned so as to cover the side surface 13c of the base 1. Alternatively, the low resistance member 21 may be positioned so as to cover the first end surface 13a, the second end surface 13b, and the side surface 13c of the base 1.

[0037] The low-resistance member 21 may be a metal plating film. The metal may be, for example, Ni (nickel), gold (Au), or the like. Such a plating film may be formed by electroless plating. When the ceramic structure 100 has the low-resistance member 21, if the base 1 becomes charged with static electricity, the static electricity can be discharged to the outside of the base 1.

[0038] A metal plating film may also be formed on the inner wall surfaces of the first cavity 11 and the second cavity 7. With this configuration, static electricity in the base 1 can be discharged from the inner wall surfaces of the first cavity 11 and the second cavity 7 as well, so that static electricity in the base 1 can be more suitably discharged to the outside of the base 1.

[0039] Although the fourth embodiment shows an example in which the base 1 has the flange portion 19, the present invention is not limited to such a configuration, and for example, a flange made of metal may be attached to the base 1 having a simple cylindrical shape. In other words, in the ceramic structure 100, the low resistance member 21 made of metal may form the flange portion. In such a case, the low resistance member 21 and the base 1 may be bonded with an adhesive.

[0040] Fifth Embodiment Next, the configuration of a ceramic structure 100 according to a fifth embodiment will be described with reference to FIG. 10 . FIG. 10 is a cross-sectional view of the ceramic structure 100 according to the fifth embodiment. In the third and fourth embodiments, an example was described in which the base 1 having the main body portion 17 and the flange portion 19 was fabricated from a single ceramic molded body. On the other hand, in the fifth embodiment, the main body portion 17 and the flange portion 19 of the base 1 may be fabricated from separate ceramic molded bodies. In other words, in the fifth embodiment, the ceramics constituting the main body portion 17 and the ceramics constituting the flange portion 19 may have different compositions.

[0041] In the fifth embodiment, the flange portion 19 may be made of ceramics having a resistance value smaller than that of the main body portion 17. Specifically, in the fifth embodiment, the resistance value of the main body portion 17 is, for example, 1×10 １２ The resistance value of the flange 19 may be, for example, 1×10 ９ Ω or less. The flange 19 may be made of, for example, ceramics containing iron oxide or titanium oxide as a conductive component. In such a case, the main body 17 may be made of ceramics that do not contain iron oxide or titanium oxide. In this way, if the flange 19 is made of, for example, ceramics containing iron oxide, static electricity in the base 1 can be discharged to the outside from the flange 19. Note that the main body 17 according to the fifth embodiment is an example of an insulating portion in the base 1. Also, the flange 19 according to the fifth embodiment is an example of a low-resistance portion in the base 1.

[0042] To produce the base 1 having the above configuration, first, a ceramic molded body is produced from a ceramic that does not contain iron oxide, which will become the main body 17 after firing. Next, a ceramic molded body made from a ceramic that contains iron oxide or titanium oxide, which will become the flange 19 after firing, is injection molded onto the surface of the ceramic molded body. The structure thus obtained is degreased and fired to obtain the base 1. Note that if the main body 17 and the flange 19 have the same main component, they can be easily integrated during firing. Here, the main component means a component that accounts for 50% by mass or more.

[0043] In the fifth embodiment, an example has been described in which the low resistance portion of the base 1 is the flange portion 19, but the configuration of the base 1 is not limited to this. For example, the low resistance portion may be provided on the surface layer of the base 1. In such a case, the surface layer of the base 1 may be made of ceramics containing iron oxide or titanium oxide. In this way, the location where the low resistance portion is formed on the base 1 is not particularly limited.

[0044] Further advantages and alternative embodiments may readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0045] The present technology can be configured as follows: (1) A ceramic structure comprising: a base made of ceramic; and a wiring layer located inside the base, wherein the base has: a first opening located on a surface of the base, a first cavity connecting the first opening and the wiring layer; and a rod-shaped terminal having a side surface and an end surface, at least a portion of which is located within the first cavity, wherein the wiring layer has a first surface, a second surface located opposite to the first surface, and a third surface connecting the first surface and the second surface, wherein the terminal faces the third surface of the wiring layer within the first cavity, a length direction of the terminal is approximately parallel to the first surface within the first cavity, and the terminal and the wiring layer are electrically connected. (2) The ceramic structure according to (1), wherein the end surface of the terminal faces the third surface of the wiring layer within the first cavity. (3) The ceramic structure according to (1) or (2), wherein the base further has a second opening located on the surface of the base and a second cavity connected to the second opening. (4) The ceramic structure according to (3), wherein the wiring layer surrounds the second cavity. (5) The ceramic structure according to (3) or (4), wherein the base has a third opening connected to the second cavity. (6) The ceramic structure according to any one of (1) to (5), wherein the base has a main body and a flange protruding from the main body. (7) The ceramic structure according to (6), wherein the flange protrudes from an end of the main body. (8) The ceramic structure according to any one of (1) to (7), wherein the base has an insulating portion and a low-resistance portion having a resistance value lower than that of the insulating portion. (9) The ceramic structure according to any one of (1) to (7), further comprising a low-resistance member located on a surface of the base, the low-resistance member having a resistance value smaller than that of the base. (10) The ceramic structure according to any one of (1) to (9), further comprising a heater, the wiring layer being a heating resistor.(11) The ceramic structure according to any one of (1) to (9), wherein the ceramic structure is a sensor holder on which a sensor is mounted, and the wiring layer is electrically connected to the sensor.

[0046] DESCRIPTION OF SYMBOLS 1 Base 3 Wiring layer 5a Second opening 5b Third opening 7 Second cavity 9 First opening 11 First cavity 11a Inner wall surface of first cavity 13a First end face 13b Second end face 13c Side face 15 Terminal 15a Third end face 15b Fourth end face 15c Side face 16 Sensor 17 Main body 19 Flange 21 Low resistance member 100 Ceramic structure, heater

Claims

1. A ceramic structure comprising: a base body made of ceramic; and a wiring layer located inside the base body, wherein the base body has a first opening located on the surface of the base body, a first cavity portion connecting the first opening and the wiring layer, and a rod-shaped terminal having a side surface and an end surface at least a portion of which is located within the first cavity portion, wherein the wiring layer has a first surface, a second surface located opposite the first surface, and a third surface connecting the first surface and the second surface, wherein the terminal faces the third surface of the wiring layer within the first cavity portion, and the longitudinal direction of the terminal is approximately parallel to the first surface within the first cavity portion, and the terminal and the wiring layer are electrically connected.

2. The ceramic structure according to claim 1, wherein the end surface of the terminal faces the third surface of the wiring layer within the first cavity.

3. The ceramic structure according to claim 1 or 2, wherein the substrate further has a second opening located on the surface of the substrate and a second cavity portion communicating with the second opening.

4. The ceramic structure according to claim 3, wherein the wiring layer surrounds the second cavity.

5. The ceramic structure according to claim 3 or 4, wherein the substrate has a third opening communicating with the second cavity.

6. The ceramic structure according to any one of claims 1 to 5, wherein the substrate has a main body and a flange protruding from the main body.

7. The ceramic structure according to claim 6, wherein the flange portion projects from the end of the body portion.

8. The ceramic structure according to any one of claims 1 to 7, wherein the substrate has an insulating portion and a low resistance portion having a resistance value lower than that of the insulating portion.

9. The ceramic structure according to any one of claims 1 to 7, further comprising a low resistance member located on the surface of said substrate, said low resistance member having a resistance value lower than that of said substrate.

10. The ceramic structure according to any one of claims 1 to 9, wherein the ceramic structure is a heater, and the wiring layer is a heating resistor.

11. The ceramic structure according to any one of claims 1 to 9, wherein the ceramic structure is a sensor holder on which a sensor is mounted, and the wiring layer is electrically connected to the sensor.

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