Joined body, power supply terminal, and airtight terminal

Abstract

A joined body according to the present disclosure includes: an insulating member having a first surface and a second surface facing the first surface, the insulating member having a through-hole penetrating from the first surface to the second surface in a first direction; a first conductive member extending in the first direction and having a first end and a second end positioned opposite the first end; and a brazing material. The through-hole has a first penetration part having a first inner surface connected to the first surface and a second inner surface connected to the first inner surface, and a second penetration part having a smaller cross-sectional area in a second direction perpendicular to the first direction than the first penetration part and connected to the second inner surface. A part of the first conductive member is positioned in the second penetration part, and the first end and the second end are positioned outside the second penetration part. The brazing material connects to a part of the surface of the first conductive member, a part of the first inner surface, and the second inner surface. A thinnest part of the brazing material having the smallest thickness in the first direction is positioned between the first conductive member and the first inner surface. The brazing material has a first filet part that is positioned between the thinnest part and the first conductive member and connects a part of the surface of the first conductive member and the second inner surface. The angle formed by an imaginary plane passing the surface of the thinnest part and parallel to the second inner surface, and the surface of the first filet part is 45° or less.

Description

Joint, power supply terminal and airtight terminal

[0001] The present invention relates to a joint, a power supply terminal, and an airtight terminal.

[0002] Conventionally, devices such as semiconductor manufacturing devices that are used while isolating the internal atmosphere from the external atmosphere have been provided with airtight terminals for conducting electrical signals between the internal atmosphere and the external atmosphere. Such airtight terminals are described, for example, in Patent Document 1.

[0003] Japanese Patent Application Laid-Open No. 2003-229368

[0004] The bonded structure according to the present disclosure includes an insulating member having a first surface and a second surface opposite the first surface and a through hole penetrating in a first direction from the first surface to the second surface, a first conductive member extending in the first direction and having a first end and a second end located opposite the first end, and a brazing filler metal. The through hole has a first through portion having a first inner surface connected to the first surface and a second inner surface connected to the first inner surface, and a second through portion having a cross-sectional area in a second direction perpendicular to the first direction that is smaller than that of the first through portion and connected to the second inner surface. A portion of the first conductive member is located within the second through portion, and the first end and the second end are located outside the second through portion. The brazing filler metal connects to a portion of the surface of the first conductive member, a portion of the first inner surface, and the second inner surface. The thinnest portion of the brazing filler metal in the first direction is located between the first conductive member and the first inner surface. The brazing filler metal has a first fillet portion located between the thinnest portion and the first conductive member and connecting a part of the surface of the first conductive member to the second inner surface, and an angle formed between the surface of the first fillet portion and an imaginary plane passing through the surface of the thinnest portion and parallel to the second inner surface is 45° or less.

[0005] A power supply terminal according to the present disclosure includes the above-described joint. A hermetic terminal according to the present disclosure includes the above-described joint and a tubular sleeve. The tubular sleeve is connected to the first surface or the second surface or surrounds the insulating member.

[0006] FIG. 1B is a plan view of a bonded body according to an embodiment of the present disclosure. FIG. 1C is an explanatory diagram for illustrating a cross section taken along line A-A shown in FIG. 1A. FIG. 1B is an enlarged explanatory diagram showing one embodiment of region X shown in FIG. 1B. FIG. 1C is an enlarged explanatory diagram showing another embodiment of region X shown in FIG. 1B. FIG. 1D is an explanatory diagram for illustrating various dimensions in a bonded body according to an embodiment of the present disclosure. FIG. 1D is an enlarged explanatory diagram showing yet another embodiment of region X shown in FIG. 1B. FIG. 1D is an enlarged explanatory diagram showing yet another embodiment of region X shown in FIG. 1B. FIG. 1D is an enlarged explanatory diagram showing yet another embodiment of region X shown in FIG. 1B. FIG. 1D is an enlarged explanatory diagram showing yet another embodiment of region X shown in FIG. 1B. FIG. 1D is an enlarged explanatory diagram showing yet another embodiment of region X shown in FIG. 1B. FIG. 1D is an enlarged explanatory diagram showing yet another embodiment of region X shown in FIG. 1B. FIG. 1D is an explanatory diagram showing an example of a case where a protruding portion is considered not to be embedded in a first fillet portion even if the protruding portion is covered with a brazing material. 10A is an explanatory diagram showing an example of a case where a protruding portion is considered not to be embedded in a first fillet portion even if the protruding portion is covered with a brazing material. FIG. 11A is an explanatory diagram showing an example of a case where a protruding portion is considered not to be embedded in a first fillet portion even if the protruding portion is covered with a brazing material. FIG. 12A is a plan view of a hermetic terminal according to an embodiment of the present disclosure. FIG. 13A is an explanatory diagram for explaining an embodiment of a cross section taken along line B-B shown in FIG. 10A. FIG. 14A is an explanatory diagram for explaining another embodiment of a cross section taken along line B-B shown in FIG. 11A. FIG. 15A is a plan view of a hermetic terminal according to another embodiment of the present disclosure. FIG. 16A is an explanatory diagram for explaining an embodiment of a cross section taken along line C-C shown in FIG.

[0007] In a joint used in a power supply terminal and an airtight terminal, a counterbore is provided in a through hole located in an insulating member to ensure a creepage distance from the viewpoint of voltage resistance. A conductive member is inserted into the through hole, and a brazing filler metal is located in the counterbore to ensure airtightness. Depending on the shape of the brazing filler metal located in the counterbore, cracks may easily occur in the insulating member, and the airtightness may be reduced. Therefore, there is a demand for a joint that reduces cracks occurring in the insulating member and has excellent airtightness.

[0008] The bonded body according to the present disclosure has the above-described configuration, which reduces cracks that occur in the insulating member and provides excellent airtightness. Furthermore, the power supply terminal and the airtight terminal according to the present disclosure include the above-described bonded body, which reduces cracks that occur in the insulating member and provides excellent airtightness.

[0009] A bonded assembly according to an embodiment of the present disclosure will be described with reference to FIGS. 1A and 1B. Hereinafter, the drawings referred to will show simplified embodiments of the present disclosure for ease of explanation. Therefore, any components not shown in the drawings may be included. Furthermore, the dimensions of the components in the drawings do not accurately represent the actual dimensions of the components, the dimensional ratios of the components, etc.

[0010] Fig. 1A is a plan view of a bonded structure 1 according to an embodiment of the present disclosure, and Fig. 1B is an explanatory view illustrating a cross section taken along line A-A shown in Fig. 1A. As shown in Fig. 1A and Fig. 1B, the bonded structure 1 according to an embodiment includes an insulating member 2 and a conductive member 3.

[0011] The insulating member 2 is a member for fixing the conductive member 3. The insulating member 2 includes, for example, ceramics. Examples of ceramics include ceramics containing aluminum oxide, aluminum nitride, or silicon nitride as a main component. In addition to the main component, the ceramic may include, for example, at least one element selected from the group consisting of silicon, calcium, and magnesium in the form of an oxide.

[0012] In this specification, the term "major component in ceramics" refers to a component that accounts for 85% by mass or more of the total 100% by mass of the components that make up the ceramics. Each component contained in the ceramics can be identified using an X-ray diffractometer using CuKα radiation, and the content of each component can be determined using, for example, an ICP (Inductively Coupled Plasma) emission spectrometer or an X-ray fluorescence analyzer.

[0013] The thickness of the insulating member 2 is not limited as long as it is thick enough to fix the conductive member 3. The insulating member 2 may have a thickness of, for example, 1 mm or more and 100 mm or less.

[0014] As shown in FIG. 1B , the insulating member 2 has a first surface 21 and a second surface 22, and a through hole 23 penetrating in a first direction D1 from the first surface 21 to the second surface 22. A conductive member 3 is inserted into the through hole 23. The through hole 23 includes a first through portion 231 and a second through portion 232. As shown in FIG. 2A , the first through portion 231 has a first inner surface 23a connected to the first surface 21 and a second inner surface 23b connected to the first inner surface 23a. The second through portion 232 has a smaller cross-sectional area in a second direction D2 perpendicular to the first direction D1 shown in FIG. 1B than the first through portion 231, and is connected to the second inner surface 23b as shown in FIG. 2A . FIG. 2A is an enlarged explanatory view showing one embodiment of region X shown in FIG. 1B .

[0015] The first through portion 231 corresponds to a so-called counterbore portion and is provided to ensure a creepage distance from the viewpoint of withstand voltage. In Fig. 1B, the first through portion 231 is provided on both the first surface 21 side and the second surface 22 side. However, it is sufficient that the first through portion 231 is provided on at least one of the first surface 21 side and the second surface 22 side.

[0016] The through hole 23 including the first through portion 231 and the second through portion 232 is not limited to any particular shape as long as it allows the conductive member 3 to be inserted therein. The through hole 23 may have a columnar shape, such as a cylindrical shape, an elliptical cylindrical shape, or a prismatic shape (such as a triangular prism, a square prism, a pentagonal prism, a hexagonal prism, or an octagonal prism). The first through portion 231 and the second through portion 232 may have the same columnar shape or different columnar shapes. Specifically, both the first through portion 231 and the second through portion 232 may be columnar, or the first through portion 231 may be columnar and the second through portion 232 may be columnar.

[0017] The through hole 23 including the first through portion 231 and the second through portion 232 may be formed using a cutting tool such as a drill or an end mill, or may be formed using a grinding tool such as a grinding wheel. For example, if the material of the insulating member 2 is press-formed or cold isostatically pressed and sintered, and then subjected to a grinding process using a grinding tool such as a grinding wheel, the first through portion 231 and the second through portion 232 with high dimensional accuracy are formed.

[0018] The conductive members 3 correspond to conductive pins and have a columnar shape with the first direction D1 as the longitudinal direction. Regarding the conductive members 3, FIG. 1A illustrates a first conductive member 31 and a second conductive member 32. The first conductive member 31 and the second conductive member 32 are defined by defining any one conductive member 3 as the "first conductive member 31" and the adjacent conductive member 3 as the "second conductive member 32." In other words, the first conductive member 31 and the second conductive member 32 are defined to conveniently distinguish between the conductive members 3. In FIGS. 1A and 1B, multiple conductive members 3 are present, and therefore, for convenience, they are distinguished as the "first conductive member 31" and the "second conductive member 32." However, multiple conductive members 3 are not necessarily present; only one first conductive member 31 may be present. Hereinafter, the first conductive member 31 and the second conductive member 32 may be simply referred to as the "conductive member 3."

[0019] The conductive member 3 includes a metal such as an Fe—Ni—Co alloy, an Fe—Ni alloy, Fe, Ti, a Ti alloy, Cu, a Cu alloy, Ni, a Ni alloy, a Cu—Ni alloy, or Mo. The conductive member 3 has a first end 311 and a second end 312 located opposite the first end 311. The conductive member 3 is not limited to any particular shape as long as it has a columnar shape, and may have, for example, a circular cylinder, an elliptical cylinder, or a prismatic shape (such as a triangular prism, a square prism, a pentagonal prism, a hexagonal prism, or an octagonal prism).

[0020] The first conductive member 31 and the second conductive member 32 may contain the same metal or different metals and may have the same columnar shape or different columnar shapes. Furthermore, the conductive member 3 may have the same columnar shape as the first through portion 231 and the second through portion 232, or may have a different columnar shape as long as it can be inserted into the first through portion 231 and the second through portion 232. Typically, the conductive member 3, the first through portion 231, and the second through portion 232 have the same columnar shape, for example, a cylindrical shape.

[0021] The length of the conductive member 3 is not limited. A portion of the conductive member 3 may be located inside the second through portion 232, and the first end 311 and the second end 312 may be located outside the second through portion 232. Being located outside the second through portion 232 also includes the case where at least one of the first end 311 and the second end 312 is located flush with the second inner surface 23b. The first conductive member 31 and the second conductive member 32 may have the same length or different lengths.

[0022] The width of the conductive member 3 is not limited. For example, when the conductive member 3 has a cylindrical shape and the first penetrating portion 231 also has a cylindrical shape, as shown in Fig. 3 , when the diameter of the conductive member 3 (first conductive member 31) is Dp and the diameter of the first penetrating portion 231 is Dz, Dp may be 90% or less of Dz. Fig. 3 is an explanatory diagram for explaining various dimensions in the bonded structure 1 according to an embodiment of the present disclosure.

[0023] When Dp is 90% or less of Dz, a relatively wide gap is ensured between the conductive member 3 and the first inner surface 23a of the first penetrating portion 231. As a result, the thinnest portion 4a of the brazing filler metal 4 (described later) tends to have a relatively wide shape, reducing stress generated near the intersection of the first inner surface 23a and the second inner surface 23b. As a result, cracks generated in the insulating member 2 are reduced, and airtightness is further improved. The lower limit is not particularly limited, and Dp may be, for example, 1% or more of Dz, or 10% or more.

[0024] The joined body 1 according to one embodiment includes a brazing filler metal 4. As shown in FIG. 2A , the brazing filler metal 4 is connected to a portion of the surface of the conductive member 3, a portion of the first inner surface 23a of the first through portion 231, and the second inner surface 23b of the first through portion 231. That is, the brazing filler metal 4 is positioned from a portion of the surface of the conductive member 3 to a portion of the first inner surface 23a so as not to expose the second inner surface 23b. Furthermore, if the gap between the conductive member 3 and the second through portion 232 is relatively wide, the brazing filler metal 4 may also flow into a portion of this gap. The brazing filler metal 4 is used to braze the conductive member 3 inserted into the through hole 23 of the insulating member 2 and ensure airtightness.

[0025] The brazing filler metal 4 is not limited as long as it can ensure airtightness. Examples of brazing filler metal 4 include brazing filler metals primarily composed of silver, such as BAg-8, BAg-8A, BAg-8B, and BAg-9. In this specification, the term "major component of brazing filler metal 4" refers to a component that accounts for 60% by mass or more of the total 100% by mass of the components constituting brazing filler metal 4. The content of each component contained in brazing filler metal 4 can be determined, for example, using an ICP emission spectrometer or an X-ray fluorescence analyzer. Furthermore, an active metal brazing filler metal, in which titanium is added to a brazing filler metal primarily composed of silver, may be used as brazing filler metal 4. The use of such an active metal brazing filler metal improves the wettability between the insulating member 2 and the brazing filler metal 4. As a result, the insulating member 2 and the conductive member 3 can be directly joined via the brazing filler metal 4 even without the metallized layer 5 described below.

[0026] The brazing filler metal 4 includes a thinnest portion 4a, which has the smallest thickness in the first direction D1, and a first fillet portion 41. The thinnest portion 4a is located between the conductive member 3 and the first inner surface 23a. That is, in the joined body 1 according to one embodiment, the brazing filler metal 4 is not located so as to expose a portion of the second inner surface 23b or the intersection of the first inner surface 23a and the second inner surface 23b. The first fillet portion 41 is located between the thinnest portion 4a and the conductive member 3, and connects a portion of the surface of the conductive member 3 to the second inner surface 23b.

[0027] Furthermore, the brazing filler metal 4 is positioned such that the angle θ1 formed between an imaginary plane F that passes through the surface of the thinnest portion 4a and is parallel to the second inner surface 23b and the surface of the first fillet portion 41 is 45° or less. When the shortest distance from the contact point between the first fillet portion 41 and the thinnest portion 4a to the conductive member 3 is defined as d1, the "angle θ1 formed between the imaginary plane F and the surface of the first fillet portion 41" refers to the angle formed between the imaginary plane F and a tangent L1 that passes through the surface S1 of the first fillet portion 41, which is located 30% of the distance d1 from this contact point.

[0028] The brazing filler metal 4 having such a configuration reduces stress generated near the intersection of the first inner surface 23 a and the second inner surface 23 b. As a result, cracks generated in the insulating member 2 are reduced, and excellent airtightness is achieved. If the angle θ1 exceeds 45°, large stress is likely to be generated near the intersection of the first inner surface 23 a and the second inner surface 23 b.

[0029] The thinnest portion 4a may be a point-like portion as shown in Fig. 2A, or may have a relatively wide shape as shown in Fig. 2B, where the brazing filler metal 4 spreads. When the thinnest portion 4a has a relatively wide shape as shown in Fig. 2B, stress generated near the intersection of the first inner surface 23a and the second inner surface 23b is reduced. As a result, cracks generated in the insulating member 2 are reduced, and airtightness is further improved.

[0030] As shown in FIGS. 4A and 4B , the brazing fillet material 4 may further include a second fillet portion 42. FIGS. 4A and 4B are enlarged explanatory views illustrating another embodiment of the region X shown in FIG. 1B . The second fillet portion 42 is located between the thinnest portion 4a and the first inner surface 23a and connects a portion of the first inner surface 23a to the second inner surface 23b. When the brazing fillet material 42 is included, the angle θ2 between the imaginary plane F and the surface of the second fillet portion 42 may be 45° or less. The "angle θ2 between the imaginary plane F and the surface of the second fillet portion 42" refers to the angle between the imaginary plane F and a tangent L2 passing through the surface S2 of the second fillet portion 42, which is located 30% of the shortest distance d2 from the tangent point between the second fillet portion 42 and the thinnest portion 4a to the first inner surface 23a, where d2 is the shortest distance from the tangent point to the thinnest portion 4a. The drawing at the end of the arrow in FIG. 4A is an enlarged view of the enclosed portion at the base of the arrow.

[0031] When the insulating member 2 has the second fillet portion 42 and the angle θ2 is 45° or less, stress generated near the intersection of the first inner surface 23a and the second inner surface 23b is further reduced, thereby further reducing cracks generated in the insulating member 2. In Fig. 4A, the thinnest portion 4a is point-like, whereas in Fig. 4B, the thinnest portion 4a has a relatively wide shape.

[0032] As shown in Figures 5A and 5B, the thinnest portion 4a of the brazing filler metal 4 may be located away from the second inner surface 23b rather than near the second inner surface 23b. That is, the brazing filler metal 4 may have a relatively large thickness in the first direction D1 even at the thinnest portion 4a. Figures 5A and 5B are enlarged explanatory views showing yet another embodiment of the region X shown in Figure 1B. Furthermore, the thinnest portion 4a may be located closer to the first inner surface 23a as shown in Figure 5A, or closer to the conductive member 3 as shown in Figure 5B.

[0033] As long as the brazing filler metal 4 does not flow out to the first surface 21 of the insulating member 2, the length in the first direction D1 of the brazing filler metal 4 in contact with the first inner surface 23a is not limited. As shown in Fig. 3, when the length in the first direction D1 of the brazing filler metal 4 in contact with the first inner surface 23a is Lb and the length in the first direction D1 of the first inner surface 23a is Lz, Lb may be 5% or more and 50% or less of Dz of the first penetration portion 231. When Lb is 5% or more and 50% or less of Lz, the necessary creepage distance is ensured and airtightness can be further improved.

[0034] In the bonded body 1 according to one embodiment, when the pitch, which is the distance between the axial centers of the first conductive member 31 and the second conductive member 32, is defined as P, Ls1 shown in the following formula (I) may be equal to or greater than the minimum creepage distance. Lz, Lb, and Dz are as described above, and detailed description thereof will be omitted. Ls1=2(Lz-Lb)+P-Dz (I)

[0035] When Ls1 in formula (I) is equal to or greater than the minimum creepage distance, it is possible to reduce the phenomenon of discharge (creepage discharge) occurring between the first conductive member 31 and the second conductive member 32 along the surface of the insulating member 2. The minimum creepage distance is the extreme distance between the surfaces of the insulating material between two conductors, and is the distance at which the two conductors are not disturbed by surface currents, i.e., the distance at which creepage discharge does not occur. Specific values ​​for the minimum creepage distance are described in the Guidelines for Explosion-Proof Electrical Equipment in Factory (International Harmonized Technical Guidelines) (JNIOSH-TR-46:2020), which conforms to the IEC 60079 series, an international standard. The pitch (P), which is the distance between the axial centers of the first conductive member 31 and the second conductive member 32, i.e., the distance between the axial centers (P) of adjacent conductive members 3, may be the same or, as shown in FIG. 1A, may differ at least in part. Furthermore, Dz may be 75% or less of P. When Dz is 75% or less of P, a sufficient thickness is ensured for the walls between the through holes 23 in the insulating member 2. Therefore, the strength of the walls is ensured and discharge penetrating inside the walls is reduced.

[0036] In the bonded structure 1 according to one embodiment, the connection surface between the first inner surface 23a and the second inner surface 23b may be an R-surface or a C-surface, as shown in FIG. 6 . Both the R-surface and the C-surface refer to a state in which the corners are chamfered. Specifically, the R-surface refers to a corner that is rounded in a curved shape. If the corner is curved, the corner may be a circular arc (an arc with a constant radius of curvature), an elliptical arc (an arc with a non-constant radius of curvature), or a concave arc (an arc with a varying radius of curvature along a concave curve) other than a circular arc or an elliptical arc. The C-surface refers to a corner that has been removed at an angle.

[0037] 6 is an enlarged explanatory view showing another embodiment of region X shown in FIG. 1B. When the connecting surface between the first inner surface 23a and the second inner surface 23b is an R-surface or a C-surface, stress generated near the intersection between the first inner surface 23a and the second inner surface 23b is further reduced. As a result, cracks generated in the insulating member 2 are further reduced.

[0038] In the bonded body 1 according to one embodiment, a portion of the first inner surface 23a may have a metallized layer 5 in contact with the second inner surface 23b, as shown in Fig. 7. Fig. 7 is an enlarged explanatory view showing yet another embodiment of the region X shown in Fig. 1B. The presence of the metallized layer 5 improves the wettability of the brazing filler metal 4, thereby improving the adhesiveness of the brazing filler metal 4. The metallized layer 5 may be located on the second inner surface 23b, as shown in Fig. 7.

[0039] There are no limitations on the metal contained in the metallized layer 5, and examples thereof include a Mo—Mn alloy and an Ag—Cu—Ti alloy. There are no limitations on the thickness of the metallized layer 5, and the thickness may be, for example, 5 μm or more and 55 μm or less. When the metallized layer 5 contains a Mo—Mn alloy, the metallized layer 5 may be formed by a molybdenum-manganese method (Mo—Mn method), and then a coating layer containing Ni, Cu, or a Cu—Ni alloy as a main component may be formed by a plating method.

[0040] 3, when the length in the first direction D1 of the metallized layer 5 in contact with the second inner surface 23b is Lm, Lm may be 5% or more of Dz and 50% or less of Lz. Dz and Lz are as described above, and detailed description thereof will be omitted. When Lm is 5% or more of Dz and 50% or less of Lz, the necessary creepage distance is ensured and airtightness can be further improved.

[0041] The brazing filler metal 4 is not limited as long as it is connected to the metallized layer 5 located on the first inner surface 23 a. That is, the brazing filler metal 4 may cover the entire metallized layer 5 located on the first inner surface 23 a, or may cover only a part of it.

[0042] As shown in FIGS. 8A and 8B , the conductive member 3 may have a protrusion 33 that protrudes from the conductive member 3 toward the first inner surface 23 a. FIGS. 8A and 8B are enlarged explanatory views showing yet another embodiment of the region X shown in FIG. 1B . The protrusion 33 is not limited to any particular form as long as it protrudes from the conductive member 3 toward the first inner surface 23 a. Examples of the protrusion 33 include a flange, a washer, and a ring. The protrusion 33 may be molded separately from the conductive member 3 and attached to the conductive member 3, or may be molded integrally with the conductive member 3.

[0043] When the conductive member 3 has the protruding portion 33, a part of the surface of the conductive member 3 at the first fillet portion 41 becomes the surface of the protruding portion 33. For example, as shown in Fig. 8B , the end face of the first fillet portion 41 on the conductive member 3 side may be positioned in the gap between the protruding portion 33 and the second inner surface 23b.

[0044] Even when the conductive member 3 has a protruding portion 33, the protruding portion 33 may be covered with the brazing filler metal 4 and embedded in the first fillet portion 41. In such a case, the embodiment is considered to be one in which the protruding portion 33 is not present. On the other hand, even if the protruding portion 33 is covered with the brazing filler metal 4, the protruding portion 33 is considered not embedded in the first fillet portion 41 in the following cases (i) to (iii), for example: (i) A surface of the protruding portion 33 facing the first inner surface 23a and the second inner surface 23b are connected by the first fillet portion 41, and at least a portion of the surface of the protruding portion 33 located opposite the second inner surface 23b is covered with the brazing filler metal 4; or (ii) A surface of the protruding portion 33 facing the first inner surface 23a and the second inner surface 23b are connected by the first fillet portion 41, and a portion of the surface of the protruding portion 33 located opposite the second inner surface 23b and the surface of the conductive member 3 are covered with the brazing filler metal 4. (iii) The surface of the protrusion 33 facing the first inner surface 23a and the second inner surface 23b are connected by a first fillet portion 41, and further, the surface of the protrusion 33 located opposite the second inner surface 23b and a portion of the surface of the conductive member 3 are coated with the solder material 4 and include a fillet.

[0045] 9A to 9C are explanatory diagrams showing an example of a case where the protrusion 33 is considered not to be embedded in the first fillet portion 41 even if the protrusion 33 is covered with the brazing filler material 4. FIG. 9A is an example showing the state (i) above. In FIG. 9A, the brazing filler material 4 covering at least a portion of the surface of the protrusion 33 located opposite the second inner surface 23b is indicated by a thick line. FIG. 9B is an example showing the state (ii) above. In FIG. 9B, the brazing filler material 4 covering the surface of the protrusion 33 located opposite the second inner surface 23b and a portion of the surface of the conductive member 3 is indicated by a thick line. FIG. 9C is an example showing the state (iii) above. In FIG. 9C, the brazing filler material 4 including the fillet covering the surface of the protrusion 33 located opposite the second inner surface 23b and a portion of the surface of the conductive member 3 is indicated by a thick line.

[0046] The shape of the protrusion 33 is not limited, and may be circular, elliptical, or polygonal (such as triangular, rectangular, pentagonal, hexagonal, or octagonal) in a plan view. For example, when the protrusion 33 has a circular shape in a plan view and the first penetrating portion 231 has a cylindrical shape, as shown in Fig. 3, the diameter Dt of the protrusion 33 may be 90% or less of Dz. Dz is as described above, and a detailed description thereof will be omitted.

[0047] When Dt is 90% or less of Dz, a relatively wide gap is ensured between the protrusion 33 and the first inner surface 23a of the first penetrating portion 231. As a result, the thinnest portion 4a of the brazing material 4 tends to have a relatively wide shape, and stress generated near the intersection of the first inner surface 23a and the second inner surface 23b is reduced. As a result, cracks generated in the insulating member 2 are reduced, and airtightness is further improved. The lower limit is not particularly limited, and Dt may be, for example, 1% or more of Dz, or 10% or more.

[0048] Even when the conductive member 3 has the protrusion 33, the length in the first direction D1 of the brazing filler metal 4 in contact with the first inner surface 23a is not limited. As shown in FIG. 3 , if the length in the first direction D1 of the brazing filler metal 4 in contact with the first inner surface 23a is Lb and the length in the first direction D1 of the first inner surface 23a is Lz, Lb may be 5% or more of Dz and 50% or less of Lz, but not less than the height in the first direction D1 from the second inner surface 23b of the protrusion 33. The "height in the first direction D1 from the second inner surface 23b of the protrusion 33" refers to the height from the second inner surface 23b to the surface of the protrusion 33 farther from the second inner surface 23b (height H shown in FIG. 3 ). When Lb is 5% or more of Dz and not less than the height in the first direction D1 from the second inner surface 23b of the protrusion 33, but not more than 50% of Lz, the necessary creepage distance can be ensured and airtightness can be further improved.

[0049] Even when the conductive member 3 has the protrusion 33, a part of the first inner surface 23a may have the metallized layer 5 in contact with the second inner surface 23b. Furthermore, the metallized layer 5 may be located on the second inner surface 23b. The metallized layer 5 is as described above, and a detailed description thereof will be omitted.

[0050] 3 , when the length in the first direction D1 of the metallized layer 5 in contact with the second inner surface 23b is Lm, Lm may be 10% or more of Dz and 50% or less of Lz at a height from the second inner surface 23b of the protrusion 33 to the height in the first direction D1. Dz and Lz are as described above, and detailed description thereof will be omitted. When Lm is 10% or more of Dz and 50% or less of Lz at a height from the second inner surface 23b of the protrusion 33 to the height in the first direction D1, the necessary creepage distance is ensured and airtightness can be further improved.

[0051] Even when the conductive member 3 has the protrusion 33, the brazing filler metal 4 is not limited as long as it is connected to the metallized layer 5 located on the first inner surface 23 a. That is, the brazing filler metal 4 may cover the entire metallized layer 5 located on the first inner surface 23 a, or may cover only a part of it.

[0052] When the bonded structure 1 according to one embodiment has a metallized layer 5, Ls2 shown in the following formula (II) may be equal to or greater than the minimum creepage distance. Lz, Lm, P, and Dz are as described above, and detailed description thereof will be omitted. Ls2=2(Lz-Lm)+P-Dz (II)

[0053] When Ls2 shown in formula (II) is equal to or greater than the minimum creepage distance, it is possible to reduce the phenomenon of discharge (creepage discharge) occurring between the first conductive member 31 and the second conductive member 32 along the surface of the insulating member 2. The minimum creepage distance is as described above, and a detailed description thereof will be omitted.

[0054] In the above-described embodiment, the first through-portions 231 are provided on both the first surface 21 side and the second surface 22 side, and as shown in FIG. 1B , the brazing filler metal 4 is located in the first through-portions 231 on both the first surface 21 side and the second surface 22 side. However, it is sufficient that the brazing filler metal 4 is located in at least one of the first through-portions 231. When the brazing filler metal 4 is located in one of the first through-portions 231, the brazing filler metal 4 may be located in the first through-portion 231 on the side exposed to high pressure when the joined body 1 is used. In other words, it is sufficient that at least the brazing filler metal 4 is located in the first through-portion 231 on the side exposed to high pressure when the joined body 1 is used.

[0055] The bonded body 1 according to one embodiment is manufactured, for example, by the following procedure. First, the insulating member 2 is prepared. In this example, the insulating member 2 is a ceramic material primarily composed of aluminum oxide. Powders of aluminum oxide, magnesium hydroxide, silicon oxide, calcium carbonate, and zirconium oxide are mixed with a dispersant for dispersing the powders, if necessary, and an organic binder. A ball mill, a bead mill, or a vibration mill is used to perform wet mixing, thereby obtaining a slurry. The wet mixing time may be, for example, 40 hours or more and 50 hours or less.

[0056] In a total of 100% by mass of the above powders, the content of magnesium hydroxide powder may be, for example, 0.87% by mass or more and 1.07% by mass or less. The content of silicon oxide powder may be, for example, 6.1% by mass or more and 7.5% by mass or less. The content of calcium carbonate powder may be, for example, 2.5% by mass or more and 3.1% by mass or less. The content of zirconium oxide may be, for example, 1.0% by mass or more and 1.3% by mass or less. The balance is aluminum oxide powder. The average particle size (D50) of the aluminum oxide powder may be, for example, 3 μm or less, or 1 μm or less.

[0057] Examples of organic binders include paraffin wax, wax emulsion (wax plus emulsifier), PVA (polyvinyl alcohol), PEG (polyethylene glycol), and PEO (polyethylene oxide).

[0058] The resulting slurry is then spray-granulated to obtain granules. The resulting granules are then molded by powder press molding or cold isostatic pressing to obtain a cylindrical compact. The resulting compact is then fired at 1550°C to 1750°C to obtain a ceramic. Next, a grinding tool such as a grindstone is used to form the first through-hole 231 and the second through-hole 232 in the resulting ceramic, thereby obtaining the insulating member 2.

[0059] If necessary, a metallized layer 5 may be formed on the first penetrating portion 231 of the obtained insulating member 2. The metallized layer 5 is formed by, for example, a Mo-Mn method. A coating layer containing Ni, Cu, or a Cu-Ni alloy as a main component may be formed on the surface of the metallized layer 5 by a plating method.

[0060] Next, the conductive member 3 is inserted into the first through portion 231 and the second through portion 232 of the insulating member 2. After the conductive member 3 is inserted, the conductive member 3 is fixed with the brazing material 4, thereby obtaining the bonded body 1 according to one embodiment.

[0061] As described above, the joined body 1 according to one embodiment has excellent airtightness and reduces cracks that occur in the insulating member 2. Therefore, the joined body 1 according to one embodiment is used as a power supply terminal, an airtight terminal, or the like that requires airtightness. A power supply terminal according to one embodiment of the present disclosure includes the joined body 1 according to one embodiment, and the joined body 1 shown in FIGS. 1A and 1B may be used as a power supply terminal.

[0062] Furthermore, as shown in Figures 10A and 10B, a hermetic terminal 10 according to an embodiment of the present disclosure includes a joined body 1 according to an embodiment and a tubular sleeve 6. Figure 10A is a plan view of the hermetic terminal 10 according to an embodiment of the present disclosure. Figure 10B is an explanatory view for explaining one embodiment of a cross section taken along line B-B shown in Figure 10A. Figure 10C is an explanatory view for explaining another embodiment of a cross section taken along line B-B shown in Figure 10A.

[0063] The cylindrical sleeve 6 is connected to the first surface 21 or the second surface 22 of the insulating member 2, or surrounds the insulating member 2. "Surrounding the insulating member 2" includes not only the case where the cylindrical sleeve 6 surrounds the entire insulating member 2 in the thickness direction, as shown in Fig. 10B, but also the case where the cylindrical sleeve 6 surrounds a portion of the insulating member 2 in the thickness direction, as shown in Fig. 10C. In other words, when the cylindrical sleeve 6 surrounds the insulating member 2, it is sufficient that the cylindrical sleeve 6 surrounds at least a portion of the insulating member 2 in the thickness direction.

[0064] The phrase "the tubular sleeve 6 is connected to the first surface 21 or the second surface 22 of the insulating member 2" refers to, for example, the configurations shown in FIGS. 11A and 11B. FIG. 11A is a plan view of a hermetic terminal 100 according to another embodiment of the present disclosure. FIG. 11B is an explanatory diagram for describing one embodiment of a cross section taken along line CC shown in FIG. 11A. In FIG. 11B, the tubular sleeve 6 is connected to both the first surface 21 and the second surface 22 of the insulating member 2. However, the tubular sleeve 6 may be connected to either the first surface 21 of the insulating member 2 or the second surface 22 of the insulating member 2.

[0065] The shape of the cylindrical sleeve 6 is not limited as long as it is cylindrical, and may be appropriately set depending on, for example, the shape of the insulating member 2. The cylindrical sleeve 6 is not limited as long as it is made of a metal, and may be made of, for example, a Fernicio alloy, an Fe—Ni alloy, an Fe—Ni—Cr—Ti—Al alloy, an Fe—Cr—Al alloy, an Fe—Co—Cr alloy, Ti, a Ti alloy, Cu, Ni, or a Cu—Ni alloy.

[0066] When the insulating member 2 contains a ceramic containing aluminum oxide as its main component, the linear expansion coefficient of these alloys is small compared to that of aluminum oxide. Therefore, if the cylindrical sleeve 6 is made of these alloys, residual stress is less likely to accumulate in the insulating member 2 even when heated and cooled repeatedly. As a result, cracks occurring in the insulating member 2 are reduced.

[0067] The embodiments of the present disclosure have been described above. However, the invention according to the present disclosure is not limited to the above-described embodiments, and various modifications and improvements are possible within the scope of the present disclosure as shown in (1) to (16) below.

[0068] (1) A bonded structure according to the present disclosure includes an insulating member having a first surface and a second surface opposite the first surface and a through hole penetrating in a first direction from the first surface to the second surface, a first conductive member extending in the first direction and having a first end and a second end located opposite the first end, and a brazing filler metal. The through hole has a first through portion having a first inner surface connected to the first surface and a second inner surface connected to the first inner surface, and a second through portion having a smaller cross-sectional area in a second direction perpendicular to the first direction than the first through portion and connected to the second inner surface. A portion of the first conductive member is located within the second through portion, and the first end and the second end are located outside the second through portion. The brazing filler metal connects to a portion of the surface of the first conductive member, a portion of the first inner surface, and the second inner surface. The thinnest portion of the brazing filler metal in the first direction is located between the first conductive member and the first inner surface. The brazing filler metal has a first fillet portion located between the thinnest portion and the first conductive member and connecting a portion of the surface of the first conductive member to the second inner surface. An imaginary plane passing through the surface of the thinnest portion and parallel to the second inner surface forms an angle of 45° or less with the surface of the first fillet portion. (2) In the joined body described in (1) above, the brazing filler metal further has a second fillet portion located between the thinnest portion and the first inner surface and connecting a portion of the first inner surface to the second inner surface. An angle of 45° or less with the imaginary plane and the surface of the second fillet portion forms an angle of 45° or less with the surface of the second fillet portion. (3) In the joined body described in (1) or (2) above, the first conductive member has a cylindrical shape, and the first penetrating portion has a cylindrical shape. When the diameter of the first conductive member is Dp and the diameter of the first penetrating portion is Dz, Dp is 90% or less of Dz. (4) In the joined body described in (3) above, where Lb is the length in the first direction of the brazing filler metal in contact with the first inner surface and Lz is the length in the first direction of the first inner surface, Lb is 5% or more of Dz and 50% or less of Lz. (5) In the joined body described in (4) above, a second conductive member is further included, and where P is the pitch, which is the distance between the axes of the first conductive member and the second conductive member, Ls1, expressed by the following formula (I), is equal to or greater than the minimum creepage distance: Ls1 = 2(Lz - Lb) + P - Dz (I) (6) In the joined body described in (4) or (5) above, a portion of the first inner surface further includes a metallized layer in contact with the second inner surface. Where Lm is the length in the first direction of the metallized layer, Lm is 5% or more of Dz and 50% or less of Lz.The brazing filler metal is connected to the metallized layer. (7) In the joined body described in any one of (1) to (6) above, the first conductive member further has a protruding portion protruding from the first conductive member toward the first inner surface. A portion of the surface of the first conductive member at the first fillet portion is the surface of the protruding portion. (8) In the joined body described in (7) above, the protruding portion has a circular shape in a plan view, and the first penetrating portion has a cylindrical shape. If the diameter of the protruding portion is Dt and the diameter of the first penetrating portion is Dz, Dt is 90% or less of Dz. (9) In the joined body described in (7) or (8) above, if the length in the first direction of the brazing filler metal in contact with the first inner surface is Lb and the length in the first direction of the first inner surface is Lz, Lb is 5% or more of Dz and 50% or less of Lz from the height in the first direction from the second inner surface of the protruding portion. (10) The joined body according to any one of (7) to (9) above further includes a metallized layer in contact with a second inner surface on a portion of the first inner surface. When the length of the metallized layer in the first direction is Lm, Lm is 10% or more of Dz and is 50% or less of Lz at least from the height of the protrusion in the first direction from the second inner surface. The brazing filler metal is connected to the metallized layer. (11) The joined body according to (10) above further includes a second conductive member, and when the pitch, which is the distance between the axes of the first conductive member and the second conductive member, is P, the length of the first inner surface in the first direction is Lz, the diameter of the first penetrating portion is Dz, and the length of the metallized layer in the first direction is Lm, Ls2, as shown in the following formula (II), is equal to or greater than the minimum creepage distance: Ls2=2(Lz-Lm)+P-Dz (II) (12) In the joined body according to any one of (1) to (11) above, the connecting surface between the first surface and the second surface is an R-surface or a C-surface. (13) In the joined body according to (5), (6), or (12) above, Dz is 75% or less of P. (14) In the joined body according to (11) or (12) above, Dz is 75% or less of P. (15) A power supply terminal according to the present disclosure includes the joined body according to any one of (1) to (14) above. (16) A hermetic terminal according to the present disclosure includes the joined body according to any one of (1) to (14) above and a tubular sleeve. The tubular sleeve is connected to the first surface or the second surface or surrounds an insulating member.

[0069] REFERENCE SIGNS LIST 1 Bonded body 2 Insulating member 21 First surface 22 Second surface 23 Through hole 231 First through portion 232 Second through portion 23a First inner surface 23b Second inner surface 3 Conductive member 31 First conductive member 311 First end 312 Second end 32 Second conductive member 33 Protruding portion 4 Brazing material 41 First fillet portion 42 Second fillet portion 4a Thinnest portion 5 Metallized layer 6 Sleeve 10, 100 Airtight terminal

Claims

1. An insulating member having a first surface and a second surface opposite to the first surface, the insulating member having a through hole penetrating in a first direction from the first surface to the second surface; a first conductive member extending in the first direction and having a first end and a second end located opposite the first end; and a brazing material, the through hole having a first penetration portion having a first inner surface connected to the first surface and a second inner surface connected to the first inner surface, and a second penetration portion having a cross-sectional area in a second direction perpendicular to the first direction smaller than that of the first penetration portion and connected to the second inner surface, a portion of the first conductive member being located within the second penetration portion, and the first end and the second end being located outside the second penetration portion, the brazing material being connected to a portion of the surface of the first conductive member, a portion of the first inner surface, and the second inner surface, and a thinnest portion of the brazing material in the first direction being located between the first conductive member and the first inner surface, The brazing material has a first fillet portion located between the thinnest portion and the first conductive member and connecting a part of a surface of the first conductive member to the second inner surface, and an angle between a virtual plane passing through the surface of the thinnest portion and parallel to the second inner surface and a surface of the first fillet portion is 45° or less.

2. The joint described in claim 1, wherein the brazing material further has a second fillet portion located between the thinnest portion and the first inner surface and connecting a part of the first inner surface to the second inner surface, and the angle between the imaginary plane and the surface of the second fillet portion is 45° or less.

3. The joint body according to claim 1 or 2, wherein the first conductive member has a cylindrical shape, the first penetrating portion has a cylindrical shape, and, when the diameter of the first conductive member is Dp and the diameter of the first penetrating portion is Dz, Dp is 90% or less of Dz.

4. The joint body described in claim 3, wherein, when the length in the first direction of the brazing material in contact with the first inner surface is Lb and the length in the first direction of the first inner surface is Lz, Lb is 5% or more of Dz and 50% or less of Lz.

5. The joined body according to claim 4, further comprising a second conductive member, wherein, when a pitch that is a distance between the axial centers of the first conductive member and the second conductive member is P, Ls1 represented by the following formula (I) is equal to or greater than the minimum creepage distance: Ls1 = 2 (Lz - Lb) + P - Dz ... (I) 6. A joint as described in claim 4 or 5, wherein a portion of the first inner surface further has a metallized layer in contact with the second inner surface, and when the length of the metallized layer in the first direction is Lm, Lm is 5% or more of Dz and 50% or less of Lz, and the brazing material is connected to the metallized layer.

7. A joint as described in any one of claims 1 to 6, wherein the first conductive member further has a protrusion protruding from the first conductive member toward the first inner surface, and a part of the surface of the first conductive member at the first fillet portion is the surface of the protrusion.

8. The joint body according to claim 7, wherein the protruding portion has a circular shape in a plan view, the first penetrating portion has a cylindrical shape, and, when a diameter of the protruding portion is Dt and a diameter of the first penetrating portion is Dz, Dt is 90% or less of Dz.

9. A joint as described in claim 7 or 8, wherein, when the length in the first direction of the brazing material in contact with the first inner surface is Lb and the length in the first direction of the first inner surface is Lz, Lb is 5% or more of Dz and is 50% or less of Lz at a height in the first direction from the second inner surface of the protrusion.

10. A joint as described in claim 8 or 9, wherein a portion of the first inner surface further has a metallized layer in contact with the second inner surface, and when the length of the metallized layer in the first direction is Lm, Lm is 5% or more of Dz and 50% or less of Lz at or above the height in the first direction from the second inner surface of the protrusion, and the brazing material is connected to the metallized layer.

11. The joined body according to claim 10, further comprising a second conductive member, wherein, when a pitch that is the distance between the axial centers of the first conductive member and the second conductive member is P, a length of the first inner surface in the first direction is Lz, a diameter of the first penetrating portion is Dz, and a length of the metallized layer in the first direction is Lm, Ls2 represented by the following formula (II) is equal to or greater than the minimum creepage distance: Ls2=2(Lz-Lm)+P-Dz (II) 12. A joint according to any one of claims 1 to 11, wherein a connecting surface between said first inner surface and said second inner surface includes at least either an R surface or a C surface.

13. The conjugate according to claim 5, 6 or 12, wherein Dz is 75% or less of P.

14. The conjugate according to claim 11 or 12, wherein Dz is 75% or less of P.

15. A power supply terminal comprising the joint body according to any one of claims 1 to 14.

16. A hermetic terminal comprising the joint according to any one of claims 1 to 14 and a tubular sleeve, said tubular sleeve being connected to said first surface or said second surface or surrounding said insulating member.

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