Brazing material, joint, method for manufacturing brazing material, and method for manufacturing joint

Abstract

To increase the joint strength in the jointed structure. [Solution] A brazing material comprising Cu, Mg, at least one first element selected from the group consisting of Sn, Sb, and Bi, and at least one second element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Ca, Ce, La, Sm, Yb, Nd, Gd, and Er.

Description

Technical Field

[0001] The present disclosure relates to a brazing material, a bonded body, a method for manufacturing a brazing material, and a method for manufacturing a bonded body.

Background Art

[0002] As a constituent material of a power control device mounted on an electric vehicle or a hybrid vehicle, a bonded body formed by joining a metal member such as copper and a ceramic material may be used. For joining a metal member and a ceramic material, a technique using an active metal brazing material containing silver (Ag) is known. In recent years, in order to solve problems such as Ag migration and high cost, a technique of joining using a material containing an active metal that does not have Ag as a main phase has been proposed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0006] According to other aspects of this disclosure, A first component made of metal, A second member is joined to the first member and is made of the same or different metal or ceramic material as the first member, A bonding layer formed on the bonding surface between the first member and the second member, The aforementioned bonding layer is Cu and Mg and, At least one first element selected from the group consisting of Sn, Sb, and Bi, A second element comprising at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Ca, Ce, La, Sm, Yb, Nd, Gd, and Er, A joint is provided.

[0007] According to yet another aspect of this disclosure, A method for manufacturing brazing material used for joining metal members and ceramic members, It contains Cu, Mg, at least one first element selected from the group consisting of Sn, Sb, and Bi, and at least one second element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Ca, Ce, La, Sm, Yb, Nd, Gd, and Er. A method for manufacturing brazing material is provided.

[0008] According to yet another aspect of this disclosure, Arrangement step: Arrange a first member made of metal and a second member made of the same or different metal as the first member, or of ceramics, so as to be laminated with a brazing material in between. The process includes a heating step of heating and holding a laminate of the first member and the second member while applying pressure in the stacking direction, As the brazing material, a material containing Cu, Mg, and at least one first element selected from the group consisting of Sn, Sb, and Bi, and at least one second element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Ca, Ce, La, Sm, Yb, Nd, Gd, and Er is used. A method for manufacturing a joined body is provided.

Advantages of the Invention

[0009] According to the present disclosure, the joining strength in the joined body can be increased.

Brief Description of the Drawings

[0010] [Figure 1] FIG. 1 is a partial cross-sectional view of a metal / ceramics joined body 100 in one aspect of the present disclosure. [Figure 2] FIG. 2 is a partially enlarged view of the broken line region A in FIG. 1. [Figure 3] FIG. 3(a) is a diagram schematically showing the shear stress applied to the joining layer 30, and (b) is a diagram schematically showing the tensile stress applied to the joining layer 30. [Figure 4] FIG. 4(a) shows a state where the metal member 10 and the ceramics member are arranged via the brazing material 50, (b) shows a state where the laminate of the metal member 10 and the ceramics member is heated while being pressurized, and (c) shows the manufactured metal / ceramics joined body 100. [Figure 5] FIG. 5 is a diagram schematically showing a state when a shear strength test is performed. [Figure 6] FIG. 6 is a partially enlarged cross-sectional photograph of the joining layer of Sample 1. [Figure 7] FIG. 7 is a partially enlarged cross-sectional photograph of the joining layer of Sample 8. [[ID=~]] [Figure 8] FIG. 8 is a partially enlarged cross-sectional photograph of the joining layer of Sample 15.

Embodiments for Carrying Out the Invention

[0011] In addition to not significantly altering the structure of the materials to be joined during heating, the resulting joint layer must be tough. The inventors focused on a Cu-Mg eutectic composition, which can significantly lower the melting point of Cu, as an active metal brazing material composition that satisfies these requirements.

[0012] However, in the Cu-Mg binary eutectic composition, the vapor pressure of Mg is high, and it is known that evaporation proceeds rapidly above 600°C when Mg is added as a single element, and above 780°C when added as MgCu2. The temperature at which bonding is possible as a brazing material is 720°C, the Cu-Mg eutectic point at which the liquid phase begins to form. However, considering the wettability of the liquid phase, it is necessary to heat to a higher temperature, which tends to accelerate the evaporation of Mg. As a result, voids due to Mg evaporation may form before a strong bonding structure is formed, and bonding layers containing such voids tend to have low bonding strength. Furthermore, while it is possible to bond before Mg evaporates by adding an excess of Mg, a large amount of intermetallic compounds known to be brittle, such as MgCu2 and CuMg2, are formed, and it tends not to be possible to maintain high bonding strength. Thus, although it is possible to significantly lower the melting temperature in the Cu-Mg binary eutectic composition, there are many factors that reduce bonding strength, making it difficult to achieve high-strength bonding.

[0013] The inventors investigated methods to suppress the evaporation of Mg from the Cu-Mg eutectic composition. They devised a method of adding elements that, by bonding with Mg, form a compound with a higher melting point than Mg, while also forming eutectices with Cu and Mg, or forming a eutectic in a ternary system including Cu and Mg. As elements that can cause such eutectic reactions, they focused on silicon (Si), germanium (Ge), tin (Sn), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi).

[0014] Therefore, the inventors added the above-mentioned elements to a Cu-Mg-based activated metal brazing material and investigated the resulting bonded layer. As a result, it was confirmed that while Sn, Sb, and Bi among the above-mentioned elements could improve the bonded strength, Si, Ge, P, and As could not sufficiently improve the bonded strength. Further investigation revealed that Si and other elements tend to have a higher reactivity with the activated metal elements described later than with Mg, and therefore the intended effect of reacting with Mg and suppressing its evaporation could not be obtained.

[0015] Based on these findings, the inventors have discovered that in Cu-Mg-based activated metal brazing materials, in order to suppress the decrease in bonding strength due to the evaporation of Mg, it is beneficial to add Sn, Sb, and Bi, which react with Mg to form compounds with higher melting points than Mg, as Mg evaporation suppressing elements.

[0016] This invention is based on the findings described above.

[0017] <One aspect of this disclosure> Hereinafter, an aspect of this disclosure will be described with reference to the aforementioned drawings. Note that the drawings used in the following description are all schematic. The dimensions and proportions of the elements shown in the drawings do not necessarily correspond to reality. Furthermore, the dimensions and proportions of the elements do not necessarily correspond between drawings. Also, in this specification, numerical ranges represented by "~" mean a range that includes the numbers written before and after "~" as the lower and upper limits, respectively.

[0018] (1) Brazing material The brazing material of this embodiment is a Cu-Mg system (mainly Cu with essential Mg) active metal brazing material with Cu as the main component (for example, 50 at% or more Cu). Specifically, the brazing material contains Cu, Mg, at least one first element selected from the group consisting of Sn, Sb, and Bi (hereinafter also referred to as the "Mg evaporation suppression element"), and at least one second element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Ca, Ce, La, Sm, Yb, Nd, Gd, and Er (hereinafter also referred to as the "active metal element"). Preferably, the brazing material contains Mg, the Mg evaporation suppression element, the active metal element, and unavoidable impurities, with the remainder being Cu. In addition, by omitting Ag, the migration resistance of the brazing material can be further improved. The brazing material can be used for joining metal members and ceramic members, or for joining metal members to metal members. In addition, unavoidable impurities refer to elements other than those intentionally added during the preparation of the wax material, such as elements derived from the raw materials.

[0019] Cu is an element that forms the solid solution that mainly constitutes the bonded layer when brazing materials are heated and joined. Cu also contributes to the ductility and malleability of the bonded layer.

[0020] Mg acts to lower the melting point of Cu, thereby reducing the bonding temperature of the brazing material. Additionally, Mg increases the wettability of the brazing material with metal and ceramic components.

[0021] The Mg evaporation-inhibiting element is an element that readily reacts with Mg when the brazing material is heated, and acts to form a compound with Mg through this reaction. This compound has a higher melting point than Mg and melts at the joining temperature, but is composed of a eutectic in which the molten Mg and other components do not easily evaporate. Therefore, the Mg evaporation-inhibiting element can suppress the evaporation of Mg by reacting with Mg during joining. In addition, when the brazing material is heated, the Mg evaporation-inhibiting element forms a ternary intermetallic compound with Cu and Mg, and acts to improve the strength of the intermetallic compound. As the Mg evaporation-inhibiting element, at least one selected from the group consisting of Sn, Sb, and Bi can be used. More preferably, the Mg evaporation-inhibiting element must include at least one of Sn and Sb (except in the case of Bi alone). Even more preferably, the first element consists of at least one of Sn and Sb (excluding Bi).

[0022] The active metal element reacts with the ceramic member when the brazing material is heated to form a compound, thereby increasing the bonding strength between the ceramic member and the bonding layer. As the active metal element, at least one selected from the group consisting of titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), yttrium (Y), calcium (Ca), cerium (Ce), lanthanum (La), samarium (Sm), ytterbium (Yb), neodymium (Nd), gadolinium (Gd), and erbium (Er) can be used. In the case of the ceramic member being Si3N4 or AlN, it is particularly preferable to use at least one selected from the group consisting of Ti, V, Nb, Cr, Mo, and Ca as the active metal element, with Ti being particularly preferred.

[0023] The content of each element is not particularly limited. For example, the Cu content is preferably 50 at% to 95 at%, and more preferably 55 at% to 80 at%. The Mg content is preferably 1 at% to 15 at%, and more preferably 3 at% to 12 at%. The Mg evaporation-inhibiting element content is preferably 1 at% to 20 at%, and more preferably 3 at% to 15 at%. The active metal element content is preferably 0.1 at% to 10 at%, and more preferably 1 at% to 10 at%. A portion of the Cu can also be replaced by other elements in a range of 1 at% or less. Furthermore, when the Mg content is X at%, and the Mg evaporation-inhibiting element content is Ya at%, it is preferable that X-6 ≤ Y ≤ X+6, and more preferably X-5 ≤ Y ≤ X+5. Including each element in such amounts is preferable for achieving a predetermined bonding strength in the bonding layer while lowering the bonding temperature of the brazing material.

[0024] The form of the brazing material is not particularly limited and can be, for example, a paste, foil, or wire. Among these, a paste form is preferred from the viewpoint of obtaining a homogeneous phase structure in the bonding layer, as described later. The paste-type brazing material is composed of a powder containing the elements mentioned above. In the case of foil, either roll quenching or rolling can be selected as the manufacturing method. In the case of wire, a general wire drawing method can be used as the manufacturing method.

[0025] In a paste-like wax material, the form in which each element is added is not particularly limited; each element may be included as a single powder, or as a compound powder containing each element. The following describes the forms in which each element is added.

[0026] Mg may be added in the form of a powder containing at least one of the following: elemental Mg, Mg solid solution containing other elements, compound with Cu (MgCu2), compound with an active metal element, or compound with an Mg evaporation-inhibiting element. Of these, it is preferable that at least a portion of the Mg is added in the form of a powder containing an intermetallic compound with an Mg evaporation-inhibiting element. For example, the Mg may be added as an alloy powder formed from Mg and an intermetallic compound containing an Mg evaporation-inhibiting element, or as an alloy powder formed from Mg and an intermetallic compound containing an Mg evaporation-inhibiting element. Alternatively, the above alloy powder may be mixed with at least one of the following: Mg powder or Mg-Cu intermetallic compound powder. By pre-forming at least a portion of the Mg as an intermetallic compound with an Mg evaporation-inhibiting element, the evaporation of Mg during the melting of the brazing material can be suppressed more reliably. Furthermore, an alloy powder refers to a material in which each element is present in an alloy form within a single particle, rather than a mixture of powders containing one element and powders containing another element. Additionally, a solid solution containing other elements refers to a material in which some of the elements constituting the solid solution in a crystal are replaced by other elements, or in which other elements have penetrated the gaps in the crystal lattice.

[0027] The alloy powder only needs to contain at least Mg and a Mg evaporation-inhibiting element, and may further contain Cu. When the Mg evaporation-inhibiting element is Sn, for example, Mg2Sn or Cu4MgSn can be used. When the Mg evaporation-inhibiting element is Sb, Mg3Sb2 or CuMgSb can be used. When the Mg evaporation-inhibiting element is Bi, Mg3Bi2 or CuMgBi can be used.

[0028] The alloy powder may be prepared by mixing, for example, Mg, a Mg evaporation-inhibiting element, and Cu as needed, dissolving the mixture, and then atomizing it to produce spherical powders containing each element. The atomization method can be selected from gas atomization, disc atomization, water atomization, or plasma atomization.

[0029] The amount of alloy powder containing Mg and Mg evaporation-inhibiting elements added is not particularly limited, but it is preferable to add an amount such that the Mg content derived from the alloy powder is 40% or more of the total Mg content in the brazing material. For example, when using alloy powder containing Mg and Mg evaporation-inhibiting elements in combination with at least one of the following: elemental Mg powder, Mg-active metal alloy powder, Mg-Cu intermetallic compound powder, etc., it is preferable to adjust the amount of alloy powder containing Mg and Mg evaporation-inhibiting elements added so that the Mg content derived from the alloy powder is 40% or more of the total Mg content in the brazing material. The amount of alloy powder added may be such that it equals 100% of the total Mg content in the brazing material, that is, only alloy powder may be added. By using such an amount, the evaporation of Mg can be suppressed more stably.

[0030] Cu may be added in the form of a powder containing at least one of the following: elemental Cu, a Cu solid solution containing other elements, an intermetallic compound with Mg (e.g., MgCu2), an intermetallic compound with an Mg evaporation-inhibiting element (e.g., Cu3Sn, Cu3Sb), an intermetallic compound with an active metal element (e.g., a Cu-Ti compound (Cu4Ti or Cu3Ti2)), or an alloy formed by elemental Cu, a solid solution, and an intermetallic compound formed with Cu.

[0031] The Mg evaporation-inhibiting element may be added in the form of a powder containing at least one of the following: the element itself, a solid solution containing other elements, a compound formed with Mg, Cu, and at least one of an active metal element, or an alloy formed by the element itself, a solid solution, and an intermetallic compound formed with Cu.

[0032] The active metal element may be added in the form of a powder containing at least one of the following: the element itself, a solid solution containing other elements, a hydride, or an intermetallic compound formed with at least one of the elements Mg, Cu, or Mg evaporation-inhibiting elements.

[0033] The amount of powder containing each element added is not particularly limited. In the brazing material, for example, it is preferable to include each powder so that the Cu content is 50 at% to 80 at%, the Mg content is 1 at% to 15 at%, the Mg evaporation-inhibiting element content is 1 at% to 20 at%, and the active metal element content is 0.1 at% to 10 at%. By setting the content of each element within the above ranges, effects such as a reduction in bonding temperature due to Mg and suppression of Mg evaporation by the Mg evaporation inhibitor can be more reliably achieved.

[0034] In brazing materials, the particle sizes of each powder containing Cu, Mg, Mg evaporation-inhibiting elements, and active metal elements can be appropriately changed according to the size of the materials to be joined and the thickness of the joining layer. For example, in the case of macrostructures such as heat exchangers and hermetic seals, the particle size may be large, and it is preferable that the average particle size D50 is between 45 μm and 150 μm. Also, for example, when the purpose is to reduce the thermal resistance of the joined body, such as in a circuit board, it is desirable to form a thin joining layer with lower thermal conductivity compared to pure metal, and it is preferable that the average particle size D50 is 45 μm or less. On the other hand, there is no particular lower limit to the average particle size, but it is preferable that the average particle size D50 is 5 μm or more from the viewpoint of suppressing the effect of surface oxidation of the powder. The average particle size D50 can be calculated, for example, using a laser diffraction particle size distribution analyzer.

[0035] The brazing material can be used as a paste if necessary, and may contain a binder, solvent, surfactant, plasticizer, dispersant, etc., in addition to the metal powder. Examples of binders include polyvinyl alcohol, ethyl cellulose, polymethacrylic acid, and polyacrylic. Examples of solvents include alcohols such as terpineol and butanediol, and toluenes. Examples of surfactants include cationic, anionic, and nonionic surfactants.

[0036] Furthermore, the method for preparing the brazing material is not particularly limited, and any conventionally known method may be used.

[0037] (2) Zygote Next, the joint will be described using Figure 1. In this embodiment, a joint formed by joining a metal member (first member) and a ceramic member (second member) (hereinafter also referred to as a metal / ceramic joint) will be described as an example. Figure 1 is a partial cross-sectional view of a metal / ceramic joint in one embodiment of this disclosure.

[0038] As shown in Figure 1, the metal / ceramics joint 100 comprises a metal member 10, a ceramic member 20 joined to the metal member 10, and a bonding layer 30 formed on the joint surface between the metal member 10 and the ceramic member 20.

[0039] (Metal components) The metal component 10 is composed of pure copper, copper alloys, pure nickel, nickel alloys, titanium alloys, stainless steel (SUS), chromium alloys, iron alloys, cobalt alloys, molybdenum alloys, etc. As pure copper, for example, oxygen-free copper, tough pitch copper, and phosphorus-deoxidized copper can be used. As copper alloys, alloys can be used in which copper (Cu) is the main element and at least one element selected from the group consisting of zinc (Zn), tin (Sn), phosphorus (P), aluminum (Al), beryllium (Be), cobalt (Co), nickel (Ni), iron (Fe), and manganese (Mn) is added. As iron alloys, Invar (registered trademark), Kovar (registered trademark), high-speed steel, and die steel can be used.

[0040] There are no particular limitations on the shape or dimensions of the metal member 10, but when the metal / ceramic bond 100 is used as a component material for an insulating circuit board, it can be, for example, a flat plate with a thickness in the range of 0.1 mm to 6.0 mm.

[0041] (Ceramic component) The ceramic component 20 is composed of, for example, at least one of a nitride, a carbide, and an oxide. Examples of nitrides include silicon nitride (Si3N4) and aluminum nitride (AlN). Examples of carbides include silicon carbide (SiC) and diamond. Examples of oxides include aluminum oxide (Al2O3).

[0042] There are no particular limitations on the shape or dimensions of the ceramic member 20, but when the metal / ceramic joint 100 is used as a component material for an insulating circuit board, it can be, for example, a flat plate with a thickness in the range of 0.2 mm to 4.0 mm.

[0043] (Joining layer) A bonding layer 30 is formed between the metal member 10 and the ceramic member 20, along their bonding surfaces 10s and 20s. The bonding layer 30 is formed from the brazing material described above and contains Cu, Mg, an Mg evaporation inhibiting element, and an active metal element.

[0044] As shown in Figure 1, the bonding layer 30 has a laminated structure consisting of a first layer 31 that forms the interface with the metal member 10 and a second layer 32 that forms the interface with the ceramic member 20 and is in contact with the first layer 31. The thickness of the first layer 31 is exemplified as 1 μm to 2000 μm, and the thickness of the second layer 32 is exemplified as 2 nm to 5000 nm.

[0045] The first layer 31 has a solid solution phase in which Cu is dissolved in Mg and at least one Mg evaporation-inhibiting element, and a compound phase containing an intermetallic compound containing Cu, Mg, and the Mg evaporation-inhibiting element. The solid solution of Mg and the Mg evaporation-inhibiting element may vary depending on the type of Mg evaporation-inhibiting element. The compound phase contains a ternary intermetallic compound containing Cu, Mg, and the Mg evaporation-inhibiting element.

[0046] (1st layer) Here, we will explain the first layer 31 in detail using Figure 2. Figure 2 is a magnified view of the dashed area A in Figure 1.

[0047] As shown in Figure 2, the first layer 31 is composed of a compound phase 31B dispersed in a solid solution phase 31A.

[0048] The solid solution phase 31A mainly consists of a solid solution in which Cu contains at least Mg and at least one Mg evaporation-inhibiting element. When the Mg evaporation-inhibiting element is Sn, Mg and Sn may be dissolved in the solid solution phase 31A. When the Mg evaporation-inhibiting element is Sb, at least Sb may be dissolved in the solid solution phase 31A, but Mg may not be dissolved. When the Mg evaporation-inhibiting element is Bi, at least Mg may be dissolved in the solid solution phase 31A, but Bi may not be dissolved. In addition, the solid solution phase 31A may also contain activated metal elements contained in the brazing material, or Si and Al contained in the ceramic member 20. In the solid solution phase 31A, the strength of the solid solution phase 31A can be improved by solid solution strengthening through the solid solution of each element.

[0049] Compound phase 31B contains a ternary intermetallic compound containing Cu, Mg, and a Mg evaporation-inhibiting element. Compound phase 31B is formed, for example, by the precipitation of intermetallic compounds. Compound phase 31B contains intermetallic compounds depending on the type of Mg evaporation-inhibiting element. Specifically, if the Mg evaporation-inhibiting element is Sn, the ternary intermetallic compound becomes Cu4MgSn. If the Mg evaporation-inhibiting element is Sb, the ternary intermetallic compound becomes CuMgSb. If the Mg evaporation-inhibiting element is Bi, the ternary intermetallic compound becomes CuMgBi. If there are two or more Mg evaporation-inhibiting elements, the ternary intermetallic compound becomes CuMg(Sn,Sb,Bi) in which some of Sn, Sb, and Bi are substituted. Although compound phase 31B contains at least a ternary intermetallic compound, Cu, Mg, and the Mg evaporation-inhibiting element may also be included as other forms of intermetallic compounds. Examples include binary intermetallic compounds composed of two elements from Cu, Mg, and Mg evaporation-inhibiting elements, elemental metals of each element, or intermetallic compounds that further include active metal elements.

[0050] In the first layer 31, it is preferable that the solid solution phase 31A, which has excellent malleability and ductility, is configured as a continuous phase, and it is more preferable that the first layer 31 has a structure in which the compound phase 31B is phase-separated in a sea-island manner within the solid solution phase 31A, as shown in Figure 2. The compound phase 31B, which contains intermetallic compounds, is more brittle than the solid solution phase 31A, which contains solid solutions, and can be a factor in reducing the bonding strength of the bonding layer 30. If this compound phase 31B is continuous in a layered structure throughout the entire bonding layer 30 and is formed at locations corresponding to stress concentration points, it may not be possible to stop crack propagation when stress load is applied to the compound phase 31B, which may significantly reduce the bonding strength. In this respect, the bonding strength can be maintained at an even higher level if the bonding layer 30 has a sea-island structure as shown in Figure 2.

[0051] In the first layer 31, it is preferable that the compound phase 31B exists uniformly dispersed throughout substantially the entire thickness and width of the first layer 31, without existing as a continuous layered phase at stress concentration points. Specifically, it is preferable that when an arbitrary region of 10 μm thickness is extracted from the first layer 31 and the area ratio of the compound phase 31B in the arbitrary region is measured, all area ratios are 40% or less. By having the compound phase 31B in an arbitrary region at a predetermined area ratio, the compound phase 31B is dispersed in the solid solution phase 31A, and the localized appearance of the compound phase 31B and the resulting decrease in bonding strength can be suppressed. The area ratio of the compound phase 31B is calculated by dividing the total area of ​​the compound phase 31B dispersed in the extracted region by the area of ​​the extracted region.

[0052] Furthermore, in the first layer 31, it is preferable that the solid solution phase 31A is configured as a continuous phase connecting the second layer 32 and the metal member 10. In other words, it is preferable that the first layer 31 has a path consisting of the solid solution phase 31A connecting the second layer 32 and the metal member 10. The solid solution phase 31A is mainly formed from a solid solution containing Cu and has excellent malleability and ductility. By configuring such a solid solution phase 31A not to be interrupted by the compound phase 31B and to continuously connect the second layer 32 and the metal member 10, it becomes possible to firmly bond the metal member 10 and the ceramic member 20, thereby improving the bonding strength. To form the continuous phase, it is preferable to form it so that the compound phase 31B is finely dispersed.

[0053] Furthermore, the bonding layer 30 is formed using the brazing material described above, thereby suppressing the generation of voids. When bonding a metal member 10 and a ceramic member 20 using a brazing material containing Mg, there is a concern that the Mg contained in the brazing material will evaporate, causing voids and pinholes (hereinafter collectively referred to as voids) to occur in the first layer 31. The presence of such voids is a factor that reduces the bonding strength between the metal member 10 and the ceramic member 20. In this embodiment, by including an element that suppresses Mg evaporation in the brazing material, the evaporation of Mg can be suppressed, and the generation of voids in the bonding layer 30 can be reduced.

[0054] Specifically, in the bonding layer 30, when the first layer 31 was observed in a cross-section perpendicular to the bonding surfaces 10s and 20s, it was approximately 10,000 μm. 2 It is preferable that no voids with an equivalent diameter of 8 μm or larger are observed within any given field of view. More preferably, no voids with an equivalent diameter of 4 μm or larger are observed, and even more preferably, no voids with an equivalent diameter of 1 μm or larger are observed. In other words, the number of voids with an equivalent diameter of 8 μm or larger is 10,000 μm. 2 Preferably, there is less than one void per unit. More preferably, the number of voids with a size of 4 μm or larger is less than one, and even more preferably, the number of voids with a size of 1 μm or larger is less than one.

[0055] In solid solution phase 31A, at least one of Mg and one of the Mg evaporation-inhibiting elements is solid-dissolved in the Cu crystal, and the amount of each element that is solid-dissolved is not particularly limited. For example, the amount of Mg that is solid-dissolved is preferably 5 at% or less. Also, for example, the amount of Sn among the Mg evaporation-inhibiting elements that is solid-dissolved is preferably 5 at% or less. Also, for example, the amount of Sb that is solid-dissolved is preferably 4 at% or less. Also, for example, the amount of Bi that is solid-dissolved is preferably 1 at% or less. The amount of solid-dissolved elements can be measured, for example, by energy-dispersive X-ray analysis (EDX) of solid solution phase 31A.

[0056] In the solid solution phase 31A, if the element that inhibits Mg evaporation is Sn, it is more preferable that the ratio A / B is between 0.5 and 2.0, where A is the amount of Mg dissolved in the solid solution phase 31A and B is the amount of the element that inhibits Mg evaporation. By dissolving Mg and Sn in such a ratio, the bonding strength of the bonding layer 30 can be increased.

[0057] Furthermore, at the interface of the first layer 31 on the metal member 10 side, an interfacial reaction layer may be formed, containing elements originating from the metal member 10 and elements originating from the bonding layer 30, due to the diffusion of metal from the metal member 10 to the first layer 31.

[0058] (2nd layer) Of the bonding layer 30, the second layer 32 that constitutes the interface with the ceramic member 20 contains a compound of an active metal element. The compound of the active metal element may contain elements derived from the ceramic member 20. For example, if the active metal element is Ti and the ceramic member 20 contains nitrides such as silicon nitride, the second layer 32 is composed mainly of titanium nitride (TiN) as the compound containing the active metal element. Also, for example, if the active metal element is Ti and the ceramic member 20 contains carbides such as silicon carbide, the second layer 32 is composed mainly of titanium carbide (TiC) as the compound containing the active metal element. Furthermore, the compound of the active metal element constituting the second layer 32 may also contain an element that suppresses Mg evaporation.

[0059] In this embodiment, the second layer 32 may further contain a silicide or aluminide of an active metal element. If the ceramic member 20 is made of Si3N4, the second layer 32 may contain a silicide of an active metal element such as Ti5Si3, and if the ceramic member 20 is made of AlN, the second layer 32 may contain an aluminide of an active metal element such as TiAl.

[0060] (Joining strength) In this embodiment, the bonding strength between the metal member 10 and the ceramic member 20 is high because the bonding layer 30 is formed with the brazing material described above. Specifically, the shear strength of the bonding layer 30 in this embodiment is 20 MPa or more. Furthermore, a shear strength of 50 MPa or more can be obtained. Moreover, a shear strength of 80 MPa or more can be obtained. In this embodiment, the tensile strength of the bonding layer 30 is 40 MPa or greater. Furthermore, a tensile strength of 90 MPa or greater can be obtained. Moreover, a tensile strength of 140 MPa or greater can be obtained.

[0061] The shear strength of the bonding layer 30, as used herein, refers to the magnitude of the shear load per unit area required to cause the bonding layer 30 to fracture (shear failure) when stress (shear stress) is applied to the bonding layer 30 in such a way that the metal member 10 and the ceramic member 20 are displaced in opposite directions along directions parallel to the bonding surfaces 10s and 20s, as shown in Figure 3(a). The tensile strength of the bonding layer 30, as shown in Figure 3(b), refers to the magnitude of the tensile load per unit area required to cause the bonding layer 30 to fracture when stress (tensile stress) is applied to the bonding layer 30 in such a way that the metal member 10 and the ceramic member 20 are pulled apart along directions perpendicular to the bonding surfaces 10s and 20s.

[0062] (3) Method for manufacturing metal / ceramic joints Next, the manufacturing method for the metal / ceramic joint 100 described above will be explained using Figures 4(a) to 4(c).

[0063] First, as shown in Figure 4(a), the metal member 10 and the ceramic member 20 described above are arranged to be laminated together via the brazing material 50.

[0064] As the brazing material 50, the brazing material described above can be used. For example, a material containing 50-80 at% Cu, 1-15 at% Mg, 1-20 at% Mg evaporation-inhibiting element, and 0.1-10 at% active metal element can be used. In the brazing material 50, Cu, Mg, Mg evaporation-inhibiting element, active metal element, etc., are preferably included as powders in the form of the compounds described above. In this case, it is preferable that at least a portion of the Mg is added in the form of an alloy powder formed from an intermetallic compound containing at least Mg and the Mg evaporation-inhibiting element. For example, a powder containing Cu, an alloy powder formed from an intermetallic compound containing at least Mg and the Mg evaporation-inhibiting element, and a powder containing an active metal element may be mixed appropriately so that each element is present in a predetermined amount.

[0065] As a method for placing the brazing material 50 on the planned joining surfaces 10s' and 20s' between the metal member 10 and the ceramic member 20, known methods such as screen printing, transfer, dispensing, inkjet, spray coating, sputtering, and vapor deposition can be used, and screen printing is more preferable. In the case of placement methods using powder, such as screen printing or dispensing, it is preferable to use the powder in the form of the paste described above. The brazing material 50 may also be used by molding powder brazing material into a preform shape. In addition, the brazing material 50 may be integrated with the metal member 10 or the ceramic member 20 before lamination and joining, and as a method of integration, cladding by rolling or metallization by heat treatment may be used.

[0066] Next, as shown in Figure 4(b), the laminate 100' of the metal member 10 and the ceramic member 20, which are arranged via the brazing material 50, is heated and held in a predetermined atmosphere while being pressed in the lamination direction. The predetermined atmosphere can be any of the following: a vacuum atmosphere (reduced pressure atmosphere), an inert gas atmosphere, or a reducing atmosphere.

[0067] The heating temperature during joining should, for example, be above the melting point of the brazing material 50 and below the melting point of the metal member 10. Preferably, it should be 115% or less of the melting point (°C) of the brazing material 50, and more preferably 101% to 110% of the melting point (°C) of the brazing material 50. This improves the diffusivity of the active metal elements and facilitates the formation of the second layer 32. When using the brazing material 50 for this purpose, for example, the heating temperature should preferably be 720°C to 1000°C, and more preferably 850°C or less. Known furnaces such as stationary batch furnaces, multi-chamber furnaces, belt conveyor furnaces, and roller hearth kilns can be used as the heat treatment furnace for joining.

[0068] Other conditions during joining include the following: Oxygen concentration: 0.01 vol ppm to 1000 vol ppm, or 0.1 vol ppm to 100 vol ppm. Pressurization: 0.5kPa or higher Retention time: There are no specific restrictions, but for example, 3 minutes to 120 minutes.

[0069] During heating, it is necessary for a liquid phase to be formed in a portion of the brazing material 50, and in addition, the active metal element must be molten in that liquid phase. For example, when using a Cu-Mg-Sb alloy with Ti as the active metal and Sb as the Mg evaporation suppressing element, this state can be created by heating the material to a temperature of 720°C or higher. However, if the heating temperature is too high, Mg may evaporate beyond the effect of the Mg evaporation suppressing element, in which case it may become difficult to form the liquid phase or voids may be generated in the formed bonding layer 30. These problems can be avoided by heating the material to a temperature of 1000°C or lower. By applying pressure of 0.5 kPa or higher, the adhesion between the metal member 10 and the ceramic member 20 via the brazing material 50 can be maintained, and the bonding strength between the metal member 10 and the ceramic member 20 can be increased. There is no particular upper limit to the pressure, but it can be, for example, around 20 kPa.

[0070] Subsequently, the heated laminate 100' is cooled. As a result, the metal / ceramics bond 100 shown in Figure 4(c) is manufactured.

[0071] (4) Effects According to this embodiment, one or more of the following effects can be obtained.

[0072] (a) The brazing material of this embodiment contains Cu, Mg, at least one Mg evaporation-inhibiting element selected from Sn, Sb, and Bi, and an active metal element. Therefore, when the brazing material is heated to join the materials, at least Cu, Mg, and the Mg evaporation-inhibiting element can be bonded together to form an intermetallic compound. This intermetallic compound readily melts at the joining temperature by undergoing a eutectic reaction with Cu, and also has the characteristic of being less likely to cause Mg to evaporate from the eutectic melt during melting due to its bond with the Mg evaporation-inhibiting element. In other words, the components contained in the brazing material bond with the Mg evaporation-inhibiting element and the like during the period from melting to solidification, thereby suppressing its evaporation. As a result, in the joint layer 30 obtained by heating the brazing material, the formation of voids due to Mg evaporation can be reduced, a dense phase structure can be formed, and high joint strength can be achieved.

[0073] (b) Furthermore, the brazing material contains Mg, which lowers the melting point of Cu, so that high bonding strength can be achieved at a low heating temperature, for example, in the range of 720°C to 1000°C. In addition, the inclusion of Mg can improve the wettability to the metal member 10 and the ceramic member 20.

[0074] (c) The brazing material contains Mg at 1 at% to 15 at%, Mg evaporation inhibiting elements at 1 at% to 20 at%, active metal elements at 0.1 at% to 10 at%, Mg content at X at%, and Mg evaporation inhibiting element content at Ya at%, such that X-6 ≤ Y ≤ X+6. By including each element in these proportions, the above effect (a) can be obtained more stably.

[0075] (d) The brazing material preferably contains Cu powder containing Cu and an alloy powder formed from an intermetallic compound containing at least Mg and an Mg evaporation-inhibiting element, and is configured in a paste form. By pre-forming an intermetallic compound with an Mg evaporation-inhibiting element for Mg, the evaporation of Mg can be more reliably suppressed when the brazing material is heated. As a result, the bonding strength can be more reliably increased.

[0076] (e) The brazing material preferably contains alloy powder such that the amount of Mg derived from the alloy powder is 40% or more of the total amount of Mg contained in the brazing material. This makes it possible to obtain the effect of (d) above more reliably.

[0077] (f) When a metal member 10 and a ceramic member 20 are joined using the brazing material of this embodiment, the joining layer 30 is formed by laminating a first layer 31 that constitutes the interface with the metal member 10 and a second layer 32 that constitutes the interface with the ceramic member 20. The first layer 31 has a solid solution phase in which Cu is dissolved in Mg and at least one Mg evaporation-inhibiting element, and a compound phase containing an intermetallic compound containing Cu, Mg, and the Mg evaporation-inhibiting element, thereby suppressing the generation of voids in the first layer 31. Furthermore, the compound phase 31B further contains the Mg evaporation-inhibiting element, thereby having higher strength compared to the case where the Mg evaporation-inhibiting element is not included. The second layer 32 contains a compound of an active metal element and acts to enhance the bonding between the metal member 10 and the joining layer 30. With a joining layer 30 having such a phase structure, the metal member 10 and the ceramic member 20 can be firmly joined, and high bonding strength can be achieved.

[0078] (g) By suppressing the generation of voids in the first layer 31 of the bonding layer 30, when the first layer 31 is observed in a cross section perpendicular to the bonding surface, it is 10,000 μm 2 It is preferable that no voids with an equivalent circular diameter of 8 μm or larger are observed within any given field of view.

[0079] (h) Preferably, the first layer 31 of the bonding layer 30 has a phase structure in which the solid solution phase 31A constitutes a continuous phase as the matrix phase, and the compound phase 31B is dispersed as island phases. When the compound phase 31B is present locally, it is prone to breakage when a load is applied to that location, but by dispersing the compound phase 31B, breakage due to load can be suppressed, and the bonding strength can be more reliably increased.

[0080] (i) In the bonding layer 30, when an arbitrary region of 10 μm thickness is extracted from the first layer 31 and the area ratio of the compound phase 31B in the arbitrary region is measured, it is preferable that all area ratios are between 20% and 40%. When the area ratio of the compound phase 31B is within the predetermined range, the compound phase 31B is finely dispersed in the solid solution phase 31A, and the effect of (h) above can be obtained more reliably.

[0081] (j) Preferably, the first layer 31 of the bonding layer 30 is composed of a solid solution phase 31A that acts as a continuous phase connecting the second layer 32 and the metal member 10. This ensures that the first layer 31 has a path made of the solid solution phase 31A, thereby more reliably increasing the bonding strength.

[0082] (k) By having the bonding layer 30 have one of the phase structures described in (f) to (j) above, it is possible to make the shear strength of the bonding layer 30 20 MPa or more. Furthermore, it is possible to make the tensile strength of the bonding layer 30 40 MPa or more.

[0083] (l) In the bonding layer 30, by forming it using a brazing material with Cu as the main phase, migration caused by using Ag as the main phase can be suppressed. In other words, high migration resistance can be achieved in the bonding layer 30.

[0084] <Other aspects of this disclosure> The aspects of this disclosure have been described in detail above. However, this disclosure is not limited to the aspects described above and can be modified in various ways without departing from its essence.

[0085] The above-described embodiment explains the case in which a metal member 10 and a ceramic member 20 are joined, but it is not limited to this, and two metal members 10 may be joined together. In this case, the two metal members 10 may be made of the same type of metal or of different types of metal.

[0086] The metal / ceramic bond 100 in this embodiment can be used, for example, as an insulating circuit board. In this case, for example, to form a circuit pattern on the metal member 10, etching may be performed after placing an etching resist on the metal member 10. The type of etching resist is not particularly limited, and for example, known thermosetting or ultraviolet curing resists can be used. The method of placing the etching resist is also not particularly limited, and methods such as placing a film-like resist film, screen printing, or inkjet coating can be employed. Furthermore, after removing the unnecessary parts of the metal member 10 from the metal / ceramic bond 100 by etching, the bonding layer 30 of any unnecessary parts may be removed. Moreover, the metal / ceramic bond 100 is not limited to use as an insulating circuit board, but can be widely applied to various applications such as heat sinks and components of internal combustion engines and power generation machines, and in these cases as well, the same effects as in the embodiment described above can be obtained. [Examples]

[0087] In this example, the prepared brazing material was used to join a metal member to a ceramic member, or to two metal members, and the joint strength of the resulting joint was evaluated. Specifically, the details are as follows.

[0088] (1) Preparation For the metal components, we prepared copper material made of oxygen-free copper with a thickness of 2.0 mm, iron alloy material (42ALLOY) with a thickness of 6.0 mm, and steel material (SUS304) with a thickness of 6.0 mm. For the ceramic components, we prepared plates made of silicon nitride (Si3N4) with a thickness of 0.3 mm, silicon carbide (SiC) with a thickness of 0.3 mm, AlN with a thickness of 0.3 mm, Al2O3 with a thickness of 0.3 mm, and diamond with a thickness of 0.3 mm.

[0089] Furthermore, powders containing Cu, Mg, Mg evaporation-inhibiting elements, and active metal elements were prepared as powders for preparing brazing materials. Specifically, as a powder containing Cu, elemental Cu powder was prepared. As powders containing Mg and Mg evaporation-inhibiting elements, five types were prepared: alloy powder formed from Cu4MgSn and Cu, alloy powder formed from CuMgSb and Cu, alloy powder formed from CuMgBi and Cu, alloy powder formed from Cu2Mg and Cu, and alloy powder formed from Cu3Sn and Cu. As a powder containing Mg, elemental Mg metal powder was prepared. As powders containing active metal elements, TiH2 powder, alloy powder consisting of CuCaSn and Cu, alloy powder consisting of Cu4MgY, Cu2Mg and Cu, and alloy powder consisting of Cu6Ce and Cu2Mg and Cu were prepared. The average particle size (D50) of each powder was set to 45 μm or less. The alloy powder was prepared using the atomization method.

[0090] (2) Preparation of brazing material First, the aforementioned powders were mixed to produce the brazing materials for Samples 1-42 and 45-232, by mixing them into pastes so that the Cu, Mg, Mg evaporation-inhibiting elements, and active metal elements were in the amounts shown in Tables 1-6. Samples 214-232 contain one of the active metal elements Cr, Mo, V, Nb, or Zr, which will be discussed later. For paste formation, polyethylene glycol and diethylene glycol monobutyl ether with molecular weights of 400 or less were used as solvents, with a solvent ratio of 9 mass% in the paste. Sample 43 was prepared in the same manner as Samples 1-42, except that Cu and Mg evaporation-inhibiting elements were not added. Similarly, Sample 44 was prepared in the same manner as Samples 1-42, except that only elemental Mg metal powder was used. In Tables 1-5, Content X represents the Mg content [at%], and Content Y represents the total content of Mg evaporation-inhibiting elements [at%].

[0091] [Table 1]

[0092] [Table 2]

[0093] [Table 3]

[0094] [Table 4]

[0095] [Table 5]

[0096] [Table 6]

[0097] (3) Fabrication of the joint Next, in samples 1 to 213, the prepared paste-like brazing material was applied by screen printing to the intended joining surface of the first member shown in Tables 1 to 6. Subsequently, the second member was placed directly on the applied paste film and pressed with a force of 8 kPa along the lamination direction, resulting in a 1.0 × 10⁻⁶ bond. -2 Joints of samples 1 to 213 were fabricated by heat treatment at 800°C for 60 minutes under a vacuum atmosphere of Pa or less (820°C for samples 43 and 44 only). For samples 214 to 232, a predetermined molar amount of one of the active metal elements (Cr, Mo, V, Nb, or Zr) was sputtered onto the planned joining surface of the first member shown in Table 6, and then a prepared paste-like brazing material was applied on top of it by screen printing. Note that the column for brazing material element ratio in Table 6 shows the ratio including the sputtered active metal element. Subsequently, the second member was placed directly on the applied paste film and pressed with a force of 8 kPa along the lamination direction, resulting in 1.0 × 10⁻⁶ -2 Joints of samples 214-232 were fabricated by heat treatment at 800°C for 60 minutes under a vacuum atmosphere of Pa or less.

[0098] (4) Evaluation The phase structure of the bonded layer and the bond strength of the fabricated joint were evaluated using the following method.

[0099] The phase structure of the bonding layer of the joint was evaluated by observing its cross-section. Specifically, the first layer was observed in a cross-section perpendicular to the bonding surface, and it was determined that (1) the solid solution phase and compound phase have a sea-island structure, (2) a path (continuous phase) consisting of the solid solution phase connecting the second layer and the copper material is secured within the first layer, and (3) approximately 10,000 μm 2 Within the field of view, it was confirmed that no voids with an equivalent circular diameter of 8 μm or larger were observed in the first layer.

[0100] Furthermore, the elements dissolved in the first layer's solid solution phase were quantified. Specifically, the content of elements dissolved in the solid solution phase was measured using an energy-dispersive X-ray spectrometer (EDX).

[0101] The joint strength of the joint was evaluated by a shear strength test. Specifically, a test specimen was prepared by processing a copper material into a cylindrical shape with a diameter of 3 mm and a height of 2 mm, exposing the joint surface of the surrounding ceramic material. As shown in Figure 5, with the ceramic material of the test specimen fixed, the cylindrical copper material was pressed using a displacement jig in a direction parallel to the joint surface, and the magnitude of the stress at which the joint layer fractured (shear failure) was measured, and the shear strength of the joint layer was calculated based on this value. The shear test position (contact height H of the displacement jig) was set at a height of 200 μm from the exposed surface of the ceramic material, and the movement speed of the displacement axis was set to 100 μm / s.

[0102] Furthermore, the tensile strength of the joint layer was calculated based on the results of the shear strength test. The tensile strength of the joint layer can be converted from the shear strength using the von Mises equation, and its magnitude is approximately 1.73 times the shear strength.

[0103] These results are shown in Tables 1 to 6.

[0104] (5) Evaluation results (Samples 1-7) Cross-sectional observation of the bonding layer of Sample 1 revealed the phase structure shown in Figure 6. Figure 6 is a magnified partial cross-sectional photograph of the bonding layer of Sample 1. As shown in Figure 6, it was confirmed that a second layer 32 containing a compound of an active metal element is formed at the interface on the ceramic member 20 side of the bonding layer 30. It was also confirmed that a first layer 31 is formed on the second layer 32. It was confirmed that the first layer 31 has a sea-island structure, with the compound phase 31B dispersed as island phases in the solid solution phase 31A of the matrix phase, which is the sea phase. Furthermore, it was confirmed that a path (continuous phase) consisting of the solid solution phase 31A connecting the second layer 32 and the copper material is secured within the first layer 31. In addition, it was confirmed that there are no voids with an equivalent circular diameter of 1 μm or larger in the first layer 31.

[0105] Furthermore, EDX measurements confirmed that compound phase 31B is formed from an intermetallic compound of Cu, Mg, and Sn, specifically Cu4MgSn. On the other hand, it was confirmed that solid solution phase 31A is composed of Mg and Sn dissolved in the Cu phase. The amount of Mg dissolved was 1.0 at%, and the amount of Sn dissolved was 1.6 at%.

[0106] Furthermore, as shown in Table 1, in Sample 1, the shear strength was 186.4 MPa, and based on this, the calculated tensile strength was confirmed to be 322.9 MPa. In other words, it was confirmed that high joint strength can be achieved.

[0107] In samples 2-7, as shown in Table 1, the Mg and Sn content in the brazing material was changed from that of sample 1, but it was confirmed that the same phase structure as sample 1 could be achieved. Furthermore, in all samples, similar to sample 1, it was confirmed that the solid solution phase 31A was composed of Mg and Sn solidly dissolved in the Cu phase, and the compound phase 31B was composed of Cu4MgSn. The solid solution amount of Mg was 5.0 at% or less, and the solid solution amount of Sn was 5.0 at% or less. In addition, the shear strength of all samples was 20 MPa or higher, and it was confirmed that the tensile strength calculated based on this was 40 MPa or higher.

[0108] (Samples 8-14) Cross-sectional observation of the bonding layer of sample 8 revealed that it has the phase structure shown in Figure 7. Figure 7 is a magnified partial cross-sectional photograph of the bonding layer of sample 8. As shown in Figure 7, it was confirmed that the bonding layer 30 of sample 8 has the same phase structure as the bonding layer 30 of sample 1. In particular, it was confirmed that the first layer 31 has a sea-island structure, with the compound phase 31B dispersed as island phases in the solid solution phase 31A of the matrix phase, the sea phase. Furthermore, it was confirmed that a path (continuous phase) consisting of the solid solution phase 31A connecting the second layer 32 and the copper material is secured within the first layer 31. In addition, it was confirmed that there are no voids with an equivalent circular diameter of 1 μm or larger in the first layer 31.

[0109] Furthermore, EDX measurements confirmed that compound phase 31B is formed from an intermetallic compound of Cu, Mg, and Sb, specifically CuMgSb. On the other hand, in solid solution phase 31A, it was confirmed that Sn was dissolved in the Cu phase, but Mg was not. The amount of dissolved Sb was 3.1 at%.

[0110] Furthermore, as shown in Table 1, in Sample 8, the shear strength was 139.5 MPa, and the tensile strength calculated based on this was confirmed to be 241.6 MPa. In other words, it was confirmed that high joint strength can be achieved.

[0111] In samples 9-14, as shown in Table 1, the Mg and Sb content in the brazing material was changed from that of sample 8, but it was confirmed that a phase structure similar to that of sample 8 could be achieved. In all samples, similar to sample 8, it was confirmed that the solid solution phase 31A was composed of Sb dissolved in the Cu phase without Mg, and the compound phase 31B was composed of CuMgSb. The amount of Sb dissolved was 4.0 at% or less. Furthermore, the shear strength of all samples was 20 MPa or higher, and it was confirmed that the tensile strength calculated based on this was 40 MPa or higher.

[0112] (Samples 15-18) Cross-sectional observation of the bonding layer 30 of sample 15 revealed that it has the phase structure shown in Figure 8. Figure 8 is a magnified partial cross-sectional photograph of the bonding layer 30 of sample 15. As shown in Figure 8, it was confirmed that the bonding layer 30 of sample 15 has the same phase structure as the bonding layer 30 of sample 1. In particular, it was confirmed that the first layer 31 has a sea-island structure, with the compound phase 31B dispersed as island phases in the solid solution phase 31A of the matrix phase, the sea phase. Furthermore, it was confirmed that a path (continuous phase) consisting of the solid solution phase 31A connecting the second layer 32 and the copper material is secured within the first layer 31. In addition, it was confirmed that there are no voids with an equivalent circular diameter of 1 μm or larger in the first layer 31.

[0113] Furthermore, EDX measurements confirmed that compound phase 31B is formed from an intermetallic compound of Cu, Mg, and Sb, specifically CuMgBi. On the other hand, in solid solution phase 31A, it was confirmed that Mg was dissolved in the Cu phase, but Bi was not. The amount of dissolved Mg was 0.4 at%.

[0114] Furthermore, as shown in Table 1, in Sample 15, the shear strength was 24.8 MPa, and the tensile strength calculated based on this was confirmed to be 43 MPa. In other words, it was confirmed that high joint strength can be achieved.

[0115] In samples 16-18, as shown in Table 1, the Mg and Bi content in the brazing material was changed from that of sample 15, but it was confirmed that a phase structure similar to that of sample 15 could be achieved. In all samples, similar to sample 15, it was confirmed that the solid solution phase 31A was composed of Mg dissolved in the Cu phase without Bi, and the compound phase 31B was composed of CuMgBi. In all samples, the solid solution amount of Mg was 5.0 at% or less. Furthermore, the shear strength of all samples was 20 MPa or higher, and it was confirmed that the tensile strength calculated based on this was 40 MPa or higher.

[0116] (Samples 19-25) In samples 19-25, the Mg, Sn, and Sb content was changed from that of samples 1 and 8, but it was confirmed that the same phase structure as samples 1 and 8 could be achieved. In all samples, it was confirmed that a sea-island structure between the solid solution phase 31A and the compound phase 31B was formed, that a path consisting of the solid solution phase 31A connecting the second layer 32 and the copper material was formed in the first layer 31, and that there were no voids with an equivalent circular diameter of 1 μm or larger.

[0117] (Samples 26-33) In samples 26-33, brazing materials were prepared to contain two elements, Sn and Sb, as Mg evaporation suppressing elements. In the bonding layer 30 of samples 26-33, a phase structure similar to that of sample 1 was confirmed. Furthermore, it was confirmed that there was a sea-island structure between the solid solution phase 31A and the compound phase 31B, that a path consisting of the solid solution phase 31A connecting the second layer 32 and the copper material was formed in the first layer 31, and that there were no voids with an equivalent circular diameter of 1 μm or larger.

[0118] Furthermore, EDX measurements confirmed that compound phase 31B was formed from an intermetallic compound of Cu, Mg, Sn, and Sb. This intermetallic compound consisted of Cu, Mg, Sn, and partially substituted Sb. On the other hand, it was confirmed that solid solution phase 31A contained Mg, Sn, and Sb in solid solution within the Cu phase.

[0119] Furthermore, as shown in Table 1, all samples had a shear strength of 20 MPa or higher, and it was confirmed that the tensile strength calculated based on this was 40 MPa or higher.

[0120] (Samples 34-39) In samples 34-39, as shown in Table 1, the brazing material was prepared and the jointed body was fabricated in the same manner as in sample 1, except that the type of ceramic component was changed from Si3N4 to SUS304, AlN, Al2O3, SiC, or diamond.

[0121] In the bonding layers 30 of samples 34-39, a phase structure similar to that of sample 1 was confirmed. Furthermore, it was confirmed that there was a sea-island structure between the solid solution phase 31A and the compound phase 31B, that a path consisting of the solid solution phase 31A connecting the second layer 32 and the copper material was formed in the first layer 31, and that there were no voids with an equivalent circular diameter of 1 μm or larger.

[0122] Furthermore, as shown in Table 1, all samples had a shear strength of 20 MPa or higher, and it was confirmed that the tensile strength calculated based on this was 40 MPa or higher.

[0123] (Samples 40-42) In samples 40-42, as shown in Table 1, an iron alloy material (42ALLOY) was used as the metal component and a Si3Ni4 substrate was used as the ceramic component. In all samples, a phase structure similar to that of sample 1 was obtained, and it was confirmed that the required bonding strength could be obtained.

[0124] (Samples 43, 44) As shown in Table 1, sample 43, which used brazing material containing Mg and Ti, and sample 44, which used brazing material containing only Mg, had a shear strength of less than 20 MPa and a tensile strength of less than 40 MPa, confirming that practical joint strength was not obtained (essentially, they were not joined). Furthermore, since these samples did not have sufficient joint strength to withstand processing for cross-sectional microstructure observation, it was not possible to observe the joined layer in a cross-section perpendicular to the joint surface.

[0125] (Samples 45-232) As shown in Tables 2 to 6, samples 45 to 232 all had shear strengths of 20 MPa or higher, and based on this, the calculated tensile strength was confirmed to be 40 MPa or higher.

[0126] <Preferred aspects of this disclosure> Preferred embodiments of this disclosure are described below. These embodiments can be combined with each other.

[0127] (Note 1) Cu and Mg and, At least one first element selected from the group consisting of Sn, Sb, and Bi, A second element comprising at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Ca, Ce, La, Sm, Yb, Nd, Gd, and Er, It is a brazing material.

[0128] (Note 2) In Appendix 1, preferably, The Mg content is 1 at% to 15 at%, the first element content is 1 at% to 20 at%, and the second element content is 0.1 at% to 10 at%, and when the Mg content is X at% and the first element content is Ya at%, X-6 ≤ Y ≤ X+6.

[0129] (Note 3) In Appendix 1 or Appendix 2, preferably, It contains Cu powder containing Cu and alloy powder having an intermetallic compound containing at least Mg and the first and second elements, and is configured in paste form.

[0130] (Note 4) A first component made of metal, A second member is joined to the first member and is made of the same or different metal or ceramic material as the first member, A bonding layer formed on the bonding surface between the first member and the second member, The aforementioned bonding layer is Cu and Mg and, At least one first element selected from the group consisting of Sn, Sb, and Bi, A second element comprising at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Ca, Ce, La, Sm, Yb, Nd, Gd, and Er, It is a composite body.

[0131] (Note 5) In Appendix 4, preferably, The aforementioned bonding layer is A first layer comprising a solid solution phase comprising a solid solution phase in which Cu, Mg, and at least one of the first element are solidly dissolved, and a compound phase comprising an intermetallic compound containing Cu, Mg, and the first element, which constitute the interface with the first member, The material comprises a second layer that forms an interface with the second member, contains a compound of the second element, and is in contact with the first layer.

[0132] (Note 6) In Appendix 5, preferably, When the first layer is observed in a cross-section perpendicular to the bonding surface, the number of voids with an equivalent circular diameter of 8 μm or larger is 10,000 μm. 2 There is less than one per person.

[0133] (Note 7) In Appendix 5, preferably, The first layer has a path made of the solid solution phase that connects the second layer and the first member.

[0134] (Note 8) In any one of the appendices 4 to 7, preferably, The shear strength of the aforementioned bonding layer is 20 MPa or more.

[0135] (Note 9) In any one of the appendices 4 to 8, preferably, The tensile strength of the aforementioned bonding layer is 40 MPa or more.

[0136] (Note 10) A method for manufacturing a brazing material used to join a first member made of metal to a second member made of the same or different type of metal, or ceramics, as the first member, A powder containing Cu, Mg, at least one first element selected from the group consisting of Sn, Sb, and Bi, and at least one second element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Ca, Ce, La, Sm, Yb, Nd, Gd, and Er is mixed with a solvent to obtain a paste-like wax material. A method for manufacturing brazing material.

[0137] (Note 11) Arrangement step: Arrange a first member made of metal and a second member made of the same or different metal as the first member, or of ceramics, so as to be laminated with a brazing material in between. The process includes a heating step of heating and holding a laminate of the first member and the second member while applying pressure in the stacking direction, The brazing material used comprises Cu, Mg, at least one first element selected from the group consisting of Sn, Sb, and Bi, and at least one second element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Ca, Ce, La, Sm, Yb, Nd, Gd, and Er. A method for manufacturing a composite body.

[0138] (Note 12) In Appendix 11, preferably, The brazing material contains Cu powder containing Cu and alloy powder formed from an intermetallic compound containing at least Mg and the first element, and is configured in a paste-like state.

[0139] (Note 13) In Appendix 11 or Appendix 12, preferably, In the heating step, the laminate is heated to a temperature of 720°C or higher and 1000°C or lower. [Explanation of symbols]

[0140] 100 Metal / Ceramic Joints 100' laminate 10 Metal component (first component) 10s joint surface 20. Ceramic component (second component) 20s joint surface 30 Bonding layer 31 1st layer 31A Solid solution phase 31B Compound phase 32 2nd layer 50 Brazing material

Claims

1. Cu and, Mg and, At least one first element selected from the group consisting of Sn, Sb, and Bi, A second element comprising at least one selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Ca, Ce, La, Sm, Yb, Nd, Gd, and Er, Brazing material.

2. The Mg content is 1 at% to 15 at%, the first element content is 1 at% to 20 at%, and the second element content is 0.1 at% to 10 at%, and when the Mg content is X at% and the first element content is Ya at%, X - 6 ≤ Y ≤ X + 6. The brazing material according to claim 1.

3. It contains Cu powder containing Cu and alloy powder having an intermetallic compound containing at least Mg, the first element and the second element, and is configured in paste form. The brazing material according to claim 1 or claim 2.

4. A first component made of metal, A second member is joined to the first member and is made of the same or different metal or ceramic as the first member, A bonding layer formed on the bonding surface between the first member and the second member, The aforementioned bonding layer is Cu and, Mg and, At least one first element selected from the group consisting of Sn, Sb, and Bi, A second element comprising at least one selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Ca, Ce, La, Sm, Yb, Nd, Gd, and Er, zygote.

5. The aforementioned bonding layer is A first layer comprising a solid solution phase in which Cu, Mg, and at least one of the first element are solidly dissolved, and a compound phase comprising an intermetallic compound containing Cu, Mg, and the first element, which constitutes the interface with the first member, A second layer comprising a compound of the second element and in contact with the first layer, which constitutes the interface with the second member, The joint according to claim 4.

6. When the first layer is observed in a cross-section perpendicular to the bonding surface, the number of voids with an equivalent circular diameter of 8 μm or larger is 10,000 μm. ２ There is less than one per person. The joint according to claim 5.

7. The first layer has a path made of the solid solution phase connecting the second layer and the first member. The joint according to claim 5.

8. The shear strength of the bonding layer is 20 MPa or more. The joint according to claim 4 or claim 5.

9. The tensile strength of the bonding layer is 40 MPa or more. The joint according to claim 4 or claim 5.

10. A method for manufacturing a brazing material used to join a first member made of metal to a second member made of the same or different type of metal, or ceramics, as the first member, A powder containing Cu, Mg, at least one first element selected from the group consisting of Sn, Sb, and Bi, and at least one second element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Ca, Ce, La, Sm, Yb, Nd, Gd, and Er is mixed with a solvent to obtain a paste-like wax material. A method for manufacturing brazing material.

11. Arrangement step: Arrange a first member made of metal and a second member made of the same or different metal as the first member, or of ceramics, so as to be laminated with a brazing material in between. The process includes a heating step of heating and holding a laminate of the first member and the second member while applying pressure in the stacking direction, The brazing material used comprises a material containing Cu, Mg, at least one first element selected from the group consisting of Sn, Sb, and Bi, and at least one second element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Ca, Ce, La, Sm, Yb, Nd, Gd, and Er. A method for manufacturing a composite body.

12. The brazing material contains Cu powder containing Cu and alloy powder formed from an intermetallic compound containing at least Mg and the first element, and is configured in paste form. A method for manufacturing a joint according to claim 11.

13. In the heating step, the laminate is heated to a temperature of 720°C or higher and 1000°C or lower. A method for manufacturing a jointed body according to claim 11 or claim 12.

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