Brazing filler metal, jointed body, method for manufacturing brazing filler metal, and method for manufacturing jointed body

Abstract

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 filler metal, a joined body, a method for manufacturing a brazing filler metal, and a method for manufacturing a joined body. [Background technology]

[0002] A joined body formed by joining a metal member such as copper to a ceramic material is sometimes used as a constituent material of a power control device mounted on an electric vehicle or a hybrid vehicle. A known technique for joining a metal member to a ceramic material is to use an active metal brazing material containing silver (Ag). Recently, to solve problems such as Ag migration and high costs, a joining technique using a material containing an active metal that does not have Ag as the main phase has been proposed (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-140929 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a technique for increasing the joint strength of a joint using an active brazing metal material that does not contain Ag as a main phase. [Means for solving the problem]

[0005] According to one aspect of the present disclosure 、 M g and at least one first element selected from the group consisting of Sn, Sb, and Bi; Ti, Zr, V, Nb, Cr, Mo, Y, Ca, and Ce and at least one second element selected from the group consisting of fruit, the balance being Cu, the content of Mg is 2.0 at% or more and 15.0 at% or less, and when the content of Mg is X at% and the total content of the first element is Y at%, 2.2≦Y≦19.7 and X−6≦Y≦X+6 are satisfied; When only Ti is contained as the second element, the content of Ti is 2.6 at% or more and 9.2 at% or less, when the second element includes any one selected from the group consisting of Zr, V, Nb, Cr, and Mo, and does not include Y, Ca, and Ce, the content of Ti is 0 at% or more and 3.9 at% or less, and the content of any one selected from the group consisting of Zr, V, Nb, Cr, and Mo is 0.4 at% or more and 0.7 at% or less, when the second element includes Ti and any one selected from the group consisting of Y, Ca, and Ce, and does not include Zr, V, Nb, Cr, and Mo, the content of Ti is 2.6 at% or more and 3.9 at% or less, and the content of any one selected from the group consisting of Y, Ca, and Ce is 1.5 at% or more and 1.7 at% or less, When only Y is contained as the second element, the content of Y is 3.5 at%. A brazing material is provided.

[0006] According to another aspect of the present disclosure, a first member made of metal; a second member joined to the first member and made of the same or different metal or ceramic as the first member; a bonding layer formed on a bonding surface between the first member and the second member, The bonding layer 、 M g and at least one first element selected from the group consisting of Sn, Sb, and Bi; Ti, Zr, V, Nb, Cr, Mo, Y, Ca, and Ce and at least one second element selected from the group consisting of fruit, the balance being Cu, the content of Mg is 2.0 at% or more and 15.0 at% or less, and when the content of Mg is X at% and the total content of the first element is Y at%, 2.2≦Y≦19.7 and X−6≦Y≦X+6 are satisfied; When only Ti is contained as the second element, the content of Ti is 2.6 at% or more and 9.2 at% or less, when the second element includes any one selected from the group consisting of Zr, V, Nb, Cr, and Mo, and does not include Y, Ca, and Ce, the content of Ti is 0 at% or more and 3.9 at% or less, and the content of any one selected from the group consisting of Zr, V, Nb, Cr, and Mo is 0.4 at% or more and 0.7 at% or less, when the second element includes Ti and any one selected from the group consisting of Y, Ca, and Ce, and does not include Zr, V, Nb, Cr, and Mo, the content of Ti is 2.6 at% or more and 3.9 at% or less, and the content of any one selected from the group consisting of Y, Ca, and Ce is 1.5 at% or more and 1.7 at% or less, When the second element contains only Y, the Y content is 3.5 at%. A conjugate is provided.

[0007] According to yet another aspect of the present disclosure, A method for manufacturing a brazing material used to join a metal member and a ceramic member. 、 M g, and at least one first element selected from the group consisting of Sn, Sb, and Bi; Ti, Zr, V, Nb, Cr, Mo, Y, Ca, and Ce and at least one second element selected from the group consisting of The remainder was composed of Cu. The powder is mixed with a solvent to obtain a paste-like brazing material. The method comprises the steps of: In the brazing filler metal, the content of the Mg is 2.0 at% or more and 15.0 at% or less, and when the content of the Mg is X at% and the total content of the first element is Y at%, 2.2≦Y≦19.7 and X−6≦Y≦X+6 are satisfied; When only Ti is contained as the second element, the content of Ti is 2.6 at% or more and 9.2 at% or less, when the second element includes any one selected from the group consisting of Zr, V, Nb, Cr, and Mo, and does not include Y, Ca, and Ce, the content of Ti is 0 at% or more and 3.9 at% or less, and the content of any one selected from the group consisting of Zr, V, Nb, Cr, and Mo is 0.4 at% or more and 0.7 at% or less, when the second element includes Ti and any one selected from the group consisting of Y, Ca, and Ce, and does not include Zr, V, Nb, Cr, and Mo, the content of Ti is 2.6 at% or more and 3.9 at% or less, and the content of any one selected from the group consisting of Y, Ca, and Ce is 1.5 at% or more and 1.7 at% or less, When only Y is contained as the second element, the content of Y is 3.5 at%. A method for manufacturing a brazing filler metal is provided.

[0008] According to yet another aspect of the present disclosure, an arrangement step of arranging a first member made of metal and a second member made of the same or different metal as the first member or a ceramic so as to be laminated via a brazing material; a heating step of heating and holding the laminate of the first member and the second member while applying pressure in the lamination direction, As the brazing material 、M g, and at least one first element selected from the group consisting of Sn, Sb, and Bi; Ti, Zr, V, Nb, Cr, Mo, Y, Ca, and Ce and at least one second element selected from the group consisting of The remainder is Cu Using materials stomach, In the brazing filler metal, the content of the Mg is 2.0 at% or more and 15.0 at% or less, and when the content of the Mg is X at% and the total content of the first element is Y at%, 2.2≦Y≦19.7 and X−6≦Y≦X+6 are satisfied; When only Ti is contained as the second element, the content of Ti is 2.6 at% or more and 9.2 at% or less, when the second element includes any one selected from the group consisting of Zr, V, Nb, Cr, and Mo, and does not include Y, Ca, and Ce, the content of Ti is 0 at% or more and 3.9 at% or less, and the content of any one selected from the group consisting of Zr, V, Nb, Cr, and Mo is 0.4 at% or more and 0.7 at% or less, when the second element includes Ti and any one selected from the group consisting of Y, Ca, and Ce, and does not include Zr, V, Nb, Cr, and Mo, the content of Ti is 2.6 at% or more and 3.9 at% or less, and the content of any one selected from the group consisting of Y, Ca, and Ce is 1.5 at% or more and 1.7 at% or less, When only Y is contained as the second element, the content of Y is 3.5 at%. A method for manufacturing the conjugate is provided. [Effects of the Invention]

[0009] According to the present disclosure, the bonding strength of the bonded body can be increased. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a partial cross-sectional view of a metal / ceramic bonded body 100 according to one embodiment of the present disclosure. [Figure 2] FIG. 2 is a partial enlarged view of the dashed line area A in FIG. [Figure 3] FIG. 3( a ) is a diagram schematically showing shear stress applied to the bonding layer 30 , and FIG. 3( b ) is a diagram schematically showing tensile stress applied to the bonding layer 30 . [Figure 4] FIG. 4(a) shows a state in which the metal member 10 and the ceramic member 20 are arranged with the brazing filler metal 50 interposed therebetween, FIG. 4(b) shows a state in which the laminate of the metal member 10 and the ceramic member 20 is heated while being pressurized, and FIG. 4(c) shows the produced metal / ceramic bonded body 100. [Figure 5] FIG. 5 is a diagram showing a schematic view of the shear strength test. [Figure 6] FIG. 6 is an enlarged photograph of a partial cross section of the bonding layer of Sample 1. [Figure 7] FIG. 7 is an enlarged photograph of a partial cross section of the bonding layer of Sample 8. [Figure 8] FIG. 8 is an enlarged photograph of a partial cross section of the bonding layer of Sample 15. DETAILED DESCRIPTION OF THE INVENTION

[0011] Brazing filler metals are required to not significantly change the structure of the materials to be joined when heated, and to produce a strong bonded layer. The inventors focused on a Cu-Mg eutectic composition, which can significantly lower the melting point of Cu, as a composition for an active metal brazing filler metal that satisfies these requirements.

[0012] However, in the Cu-Mg binary eutectic composition, magnesium vapor pressure is high, and evaporation occurs rapidly above 600°C when magnesium is added alone, and above 780°C when added as MgCu2. Although the temperature at which brazing filler metals can be used is 720°C, the Cu-Mg eutectic point at which the liquid phase begins to form, higher temperatures are required, which tends to accelerate magnesium evaporation. As a result, voids can form due to magnesium evaporation before a strong bond structure is formed, and bonding layers containing such voids tend to have low bond strength. Furthermore, adding excess magnesium allows bonding before the magnesium evaporates, but this leads to the formation of large amounts of brittle intermetallic compounds such as MgCu2 and CuMg2, which tend to reduce bond strength. Thus, although the Cu-Mg binary eutectic composition can significantly lower the melting temperature, there are many factors that reduce bond strength, making it difficult to achieve high-strength bonds.

[0013] The present inventors have investigated methods for suppressing the evaporation of Mg from Cu-Mg eutectic compositions. They have devised the addition of an element that combines with Mg to form a compound with a higher melting point than Mg, while forming a eutectic with each of Cu and Mg, or a ternary eutectic with Cu and Mg. They have focused on elements that undergo such eutectic reactions, such as silicon (Si), germanium (Ge), tin (Sn), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi).

[0014] Therefore, the present inventors added the above elements to a Cu-Mg-based active metal brazing filler metal and investigated the resulting bonding layer. As a result, it was confirmed that, among the above elements, Sn, Sb, and Bi could improve the bonding strength, but Si, Ge, P, and As could not sufficiently improve the bonding strength. Further investigation into this point revealed that Si and other elements tend to be more reactive with the active metal elements described below than with Mg, and therefore the intended effect of reacting with Mg and suppressing its evaporation could not be achieved.

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

[0016] The present invention was made based on the above findings.

[0017] <One aspect of the present disclosure> Hereinafter, one embodiment of the present disclosure will be described with reference to the above-mentioned drawings. Note that all drawings used in the following description are schematic. The dimensions and proportions of each element shown in the drawings do not necessarily correspond to those in reality. Furthermore, the dimensions and proportions of each element do not necessarily correspond between drawings. Furthermore, in this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits.

[0018] (1) Brazing material The brazing filler metal of this embodiment is a Cu-Mg-based (mainly Cu with Mg as an essential component) active metal brazing filler metal containing Cu as the main component (e.g., 50 at% or more Cu). Specifically, the brazing filler metal 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 suppressing 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"). The brazing filler metal preferably contains Mg, the Mg evaporation suppressing element, the active metal element, and unavoidable impurities, with the balance being Cu. In addition, by not including Ag, the migration resistance of the brazing filler metal can be further improved. The brazing filler metal can be used to join metal members to ceramic members or to join metal members to each other. The inevitable impurities are elements other than those intentionally added when preparing the brazing material, such as elements derived from the raw materials.

[0019] Cu is an element that forms a solid solution that mainly constitutes the bonding layer when the brazing filler metal is heated and bonded, and Cu also contributes to the ductility and malleability of the bonding layer.

[0020] Mg acts to lower the melting point of Cu, thereby lowering the joining temperature of the brazing filler metal, and also acts to increase the wettability of the brazing filler metal with metal and ceramic members.

[0021] The Mg evaporation inhibitor is an element that readily reacts with Mg when the brazing filler metal is heated, and acts to form a compound with Mg through the reaction with Mg. This compound has a higher melting point than Mg and is formed as a eutectic, which melts at the joining temperature but prevents the molten components, such as Mg, from evaporating. Therefore, the Mg evaporation inhibitor reacts with Mg during joining to suppress Mg evaporation. Furthermore, the Mg evaporation inhibitor forms a ternary intermetallic compound with Cu or Mg when the brazing filler metal is heated, and acts to improve the strength of the intermetallic compound. As the Mg evaporation inhibitor, at least one element selected from the group consisting of Sn, Sb, and Bi can be used. More preferably, the Mg evaporation inhibitor always contains at least one of Sn and Sb (except when Bi is used alone). Even more preferably, the first element contains at least one of Sn and Sb (without containing Bi).

[0022] The active metal element reacts with the ceramic member to form a compound when the brazing filler metal is heated, thereby enhancing the bonding strength between the ceramic member and the bonding layer. The active metal element can be 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). When the ceramic member is Si3N4 or AlN, it is preferable to use at least one selected from the group consisting of Ti, V, Nb, Cr, Mo, and Ca, 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 inhibitor 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 Cu may be contained in the form of other elements in a range of 1 at% or less. Furthermore, when the Mg content is X at% and the Mg evaporation inhibitor content is Y at%, it is preferable that X-6≦Y≦X+6 and more preferably X-5≦Y≦X+5. Containing each element in such a content is preferable in terms of 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 it can be, for example, a paste, foil, or wire. Among these, a paste is preferable from the viewpoint of obtaining a uniform phase structure in the bonding layer, which will be described later. The paste brazing material is composed of powder containing the elements described above. In the case of a foil, either roll quenching or rolling can be selected as the manufacturing method. In the case of a wire, a general wire drawing method can be used as the manufacturing method.

[0025] In the paste-like brazing filler metal, the addition form of each element is not particularly limited, and each element may be contained as a single powder or as a compound powder containing each element. The addition form of each element will be described below.

[0026] Mg may be added in the form of a powder containing at least one of the following: simple Mg, a Mg solid solution containing other elements, a compound with Cu (MgCu), a compound with an active metal element, or a compound with a Mg evaporation-inhibiting element. Among these, it is preferable to add at least a portion of Mg in the form of a powder containing an intermetallic compound with a Mg evaporation-inhibiting element. For example, Mg may be added as an alloy powder formed from Mg and an intermetallic compound containing a Mg evaporation-inhibiting element, or as an alloy powder formed from an intermetallic compound containing Mg and a Mg evaporation-inhibiting element and the Mg evaporation-inhibiting element. Alternatively, the alloy powder may be mixed with at least one of Mg powder and an Mg-Cu intermetallic compound powder. By preliminarily forming at least a portion of Mg into an intermetallic compound with a Mg evaporation-inhibiting element, evaporation of Mg during melting of the brazing filler metal can be more reliably suppressed. Note that an alloy powder is not a mixture of a powder containing one element and a powder containing another element, but refers to a powder in which each element is contained in the form of an alloy in a single particle. Also, a solid solution containing another element refers to a solid solution in which part of the element that constitutes the solid solution in the crystal is replaced with another element, or a solid solution in which another element has penetrated into the gaps in the crystal lattice.

[0027] The alloy powder 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 as the alloy powder. When the Mg evaporation inhibiting element is Sb, for example, Mg3Sb2 or CuMgSb can be used. When the Mg evaporation inhibiting element is Bi, for example, Mg3Bi2 or CuMgBi can be used.

[0028] The alloy powder may be prepared by mixing and dissolving Mg, a Mg evaporation suppressing element, and optionally Cu, and then atomizing the mixture to form spherical powders containing each element. The atomization method can be selected from gas atomization, disk atomization, water atomization, and plasma atomization.

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

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

[0033] The amount of powder containing each element added is not particularly limited, and it is preferable that the brazing filler metal contains each powder so that, for example, the Cu content is 50 at% to 80 at%, the Mg content is 1 at% to 15 at%, the Mg evaporation inhibitor 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, it is possible to more reliably achieve the effects of lowering the joining temperature by Mg and suppressing Mg evaporation by the Mg evaporation inhibitor.

[0034] In brazing filler metals, the particle sizes of the powders containing Cu, Mg, Mg evaporation inhibitors, and active metal elements can be adjusted depending on 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 hermetically sealed structures, the particle sizes may be large, preferably with an average particle size D50 of 45 μm to 150 μm. Furthermore, for example, when the goal is to reduce the thermal resistance of a joining structure such as a circuit board, it is desirable to form a thin joining layer with lower thermal conductivity than pure metals, and an average particle size D50 of 45 μm or less is preferred. On the other hand, while there is no particular lower limit for the average particle size, an average particle size D50 of 5 μm or more is preferred to suppress the effects of powder surface oxidation. The average particle size D50 can be calculated, for example, using a laser diffraction particle size analyzer.

[0035] The brazing material can be used as a paste of metal powder as needed, and may contain binders, solvents, surfactants, plasticizers, dispersants, etc. in addition to the metal powder. Examples of binders that can be used include polyvinyl alcohol, ethyl cellulose, polymethacrylic acid, and polyacrylic. Examples of solvents that can be used include alcohols such as terpineol and butanediol, and toluenes. Examples of surfactants that can be used include cationic, anionic, and nonionic activators.

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

[0037] (2) Zygote Next, the bonded body will be described with reference to Fig. 1. In this embodiment, a bonded body (hereinafter also referred to as a metal / ceramic bonded body) in which a metal member (first member) and a ceramic member (second member) are bonded together will be described as an example. Fig. 1 is a partial cross-sectional view of a metal / ceramic bonded body according to one embodiment of the present disclosure.

[0038] As shown in FIG. 1, a metal / ceramic bonded body 100 includes a metal member 10, a ceramic member 20 bonded to the metal member 10, and a bonding layer 30 formed on the bonding surface between the metal member 10 and the ceramic member 20.

[0039] (Metal parts) The metal member 10 may be made of pure copper, copper alloy, pure nickel, nickel alloy, titanium alloy, stainless steel (SUS), chromium-based alloy, iron-based alloy, cobalt-based alloy, molybdenum-based alloy, or the like. Examples of pure copper include oxygen-free copper, tough pitch copper, and phosphorus-deoxidized copper. Examples of copper alloys include alloys containing copper (Cu) as the main element and containing 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). Examples of iron-based alloys include Invar®, Kovar®, high-speed steel, and die steel.

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

[0041] (ceramic components) The ceramic member 20 is configured to include at least one of, for example, nitrides, carbides, and oxides. 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 bonded body 100 is used as a constituent material of an insulating circuit board, it can be, for example, a flat plate having a thickness in the range of 0.2 mm to 4.0 mm.

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

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

[0045] The first layer 31 has a solid solution phase in which at least one of Mg and a Mg evaporation inhibiting element is solid-solved in Cu, 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, the first layer 31 will be specifically described with reference to Fig. 2. Fig. 2 is a partial enlarged view of the dashed line area A in Fig. 1.

[0047] As shown in FIG. 2, the first layer 31 is configured by dispersing a compound phase 31B in a solid solution phase 31A.

[0048] The solid solution phase 31A is mainly composed of a solid solution of Cu, at least Mg, and at least one of the Mg evaporation inhibitors. When the Mg evaporation inhibitor is Sn, the solid solution phase 31A may contain Mg and Sn. When the Mg evaporation inhibitor is Sb, the solid solution phase 31A may contain at least Sb, but not Mg. When the Mg evaporation inhibitor is Bi, the solid solution phase 31A may contain at least Mg, but not Bi. The solid solution phase 31A may also contain active metal elements contained in the brazing filler metal, Si, Al, and the like contained in the ceramic member 20. When each element is dissolved in the solid solution phase 31A, the strength of the solid solution phase 31A can be improved by solution strengthening.

[0049] The compound phase 31B contains a ternary intermetallic compound containing Cu, Mg, and a Mg evaporation inhibitor. The compound phase 31B is formed, for example, by the precipitation of intermetallic compounds. The compound phase 31B contains an intermetallic compound according to the type of Mg evaporation inhibitor. Specifically, when the Mg evaporation inhibitor is Sn, the ternary intermetallic compound is Cu4MgSn. When the Mg evaporation inhibitor is Sb, the ternary intermetallic compound is CuMgSb. When the Mg evaporation inhibitor is Bi, the ternary intermetallic compound is CuMgBi. When two or more types of Mg evaporation inhibitors are present, the ternary intermetallic compound is CuMg(Sn, Sb, Bi) in which Sn, Sb, and Bi are partially substituted. Note that the compound phase 31B contains at least a ternary intermetallic compound, but Cu, Mg, and the Mg evaporation inhibitor may also be contained as intermetallic compounds in other forms. For example, binary intermetallic compounds composed of two of Cu, Mg and Mg evaporation inhibiting elements, simple metals of each element, or intermetallic compounds further containing an active metal element may be mentioned.

[0050] In the first layer 31, the solid solution phase 31A, which has excellent malleability and ductility, is preferably configured as a continuous phase. More preferably, the first layer 31 has a structure in which the compound phase 31B is phase-separated into a sea-island structure within the solid solution phase 31A, as shown in FIG. 2. The compound phase 31B containing an intermetallic compound is more brittle than the solid solution phase 31A containing a solid solution, which can reduce the bonding strength of the bonding layer 30. If this compound phase 31B is continuous in a layered structure throughout the bonding layer 30 and formed at locations corresponding to stress concentration points, crack propagation cannot be stopped when stress is applied to the compound phase 31B, which may significantly reduce the bonding strength. In this regard, by having the sea-island structure shown in FIG. 2, the bonding layer 30 can maintain even higher bonding strength.

[0051] In the first layer 31, the compound phase 31B is preferably uniformly dispersed throughout the entire thickness and width of the first layer 31, rather than existing as a layered continuous phase at stress concentration locations. Specifically, when any region in 10 μm thickness units is extracted from the first layer 31 and the area ratio of the compound phase 31B in the region is measured, it is preferable that all area ratios are 40% or less. The presence of the compound phase 31B in the region at a predetermined area ratio allows the compound phase 31B to be dispersed in the solid-solution phase 31A, thereby preventing localized appearance of the compound phase 31B and the resulting decrease in bonding strength. 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, the solid solution phase 31A is preferably configured as a continuous phase connecting the second layer 32 and the metal member 10. That is, the first layer 31 preferably has a path formed by the solid solution phase 31A connecting the second layer 32 and the metal member 10. The solid solution phase 31A is mainly formed of a solid solution containing Cu and has excellent malleability and ductility. By configuring such a solid solution phase 31A to continuously connect the second layer 32 and the metal member 10 without being separated by the compound phase 31B, it is 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 the compound phase 31B so that it is finely dispersed.

[0053] Furthermore, the bonding layer 30 is formed using the above-mentioned brazing filler metal, thereby suppressing the generation of voids. When the metal member 10 and the ceramic member 20 are bonded using a brazing filler metal containing Mg, there is a concern that voids or pinholes (hereinafter, collectively referred to as voids) may be generated in the first layer 31 due to evaporation of Mg contained in the brazing filler metal. The presence of such voids can reduce the bonding strength between the metal member 10 and the ceramic member 20. In this regard, in this embodiment, the brazing filler metal contains an element that suppresses Mg evaporation, thereby suppressing the evaporation of Mg and reducing the generation of voids in the bonding layer 30.

[0054] Specifically, in the bonding layer 30, when the first layer 31 is observed in a cross section perpendicular to the bonding surfaces 10s and 20s, the thickness of the first layer 31 is approximately 10,000 μm. 2 It is preferable that no voids having a circular equivalent diameter of 8 μm or more are observed within any field of view. More preferably, no voids having a circular equivalent diameter of 4 μm or more are observed, and even more preferably, no voids having a circular equivalent diameter of 1 μm or more are observed. In other words, the number of voids having a circular equivalent diameter of 8 μm or more is 10,000 μm. 2 More preferably, the number of voids having a size of 4 μm or more is less than 1, and even more preferably, the number of voids having a size of 1 μm or more is less than 1.

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

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

[0057] In addition, at the interface of the first layer 31 on the metal member 10 side, an interfacial reaction layer containing elements derived from the metal member 10 and elements derived from the bonding layer 30 may be formed due to 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 constituting the interface with the ceramic member 20 contains a compound of an active metal element. The compound of the active metal element may contain an element derived from the ceramic member 20. For example, when the active metal element is Ti and the ceramic member 20 contains a nitride such as silicon nitride, the second layer 32 is composed mainly of titanium nitride (TiN) as a compound containing the active metal element. Furthermore, when the active metal element is Ti and the ceramic member 20 contains a carbide such as silicon carbide, the second layer 32 is composed mainly of titanium carbide (TiC) as a compound containing the active metal element. Furthermore, the compound of the active metal element constituting the second layer 32 may also contain a Mg evaporation inhibiting element.

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

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

[0061] The shear strength of the bonding layer 30 herein refers to the magnitude of the shear load per unit area required to fracture (shear fracture) the bonding layer 30 when stress (shear stress) is applied to the bonding layer 30 so as to displace the metal member 10 and the ceramic member 20 in opposite directions parallel to the bonding surfaces 10s and 20s, as shown in Fig. 3(a). The tensile strength of the bonding layer 30 refers to the magnitude of the tensile load per unit area required to fracture the bonding layer 30 when stress (tensile stress) is applied to the bonding layer 30 so as to pull the metal member 10 and the ceramic member 20 apart in a direction perpendicular to the bonding surfaces 10s and 20s, as shown in Fig. 3(b).

[0062] (3) Manufacturing method of metal / ceramic bonded body Next, a method for producing the above-mentioned metal / ceramic bonded body 100 will be described with reference to FIGS. 4(a) to 4(c).

[0063] First, as shown in FIG. 4(a), the metal member 10 and the ceramic member 20 are arranged so as to be stacked with the brazing material 50 interposed therebetween.

[0064] The brazing filler metal 50 can be any of the brazing filler metals described above, including, for example, a material containing 50-80 at% Cu, 1-15 at% Mg, 1-20 at% Mg evaporation inhibitor, and 0.1-10 at% active metal element. In the brazing filler metal 50, Cu, Mg, the Mg evaporation inhibitor, and the active metal element may be contained in the form of powders of the aforementioned compounds. 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 inhibitor. For example, a powder containing Cu, an alloy powder formed from an intermetallic compound containing at least Mg and the Mg evaporation inhibitor, and a powder containing the active metal element may be appropriately mixed so that the respective elements have predetermined contents.

[0065] The brazing filler metal 50 can be applied to the intended joining surfaces 10s' and 20s' of the metal member 10 and the ceramic member 20 by known methods such as screen printing, transfer printing, dispensing, inkjet printing, spray coating, sputtering, and vapor deposition, with screen printing being preferred. In the case of powder application methods such as screen printing and dispensing, the powder is preferably used in the form of a paste as described above. The brazing filler metal 50 may be formed into a preform shape before use. The brazing filler metal 50 may also be integrated with the metal member 10 or the ceramic member 20 before lamination and bonded to them. The integration method may be cladding by rolling or metallizing by heat treatment.

[0066] 4(b), the laminate 100′ of the metal member 10 and the ceramic member 20 arranged with the brazing filler metal 50 interposed therebetween is heated and held in a predetermined atmosphere while being pressurized in the lamination direction. The predetermined atmosphere may be any one of a vacuum atmosphere (reduced pressure atmosphere), an inert gas atmosphere, and a reducing atmosphere.

[0067] The heating temperature during bonding may be, for example, equal to or higher than the melting point of the brazing filler metal 50 and equal to or lower than the melting point of the metal members 10. The temperature is preferably equal to or lower than 115% of the melting point (°C) of the brazing filler metal 50, and more preferably equal to or higher than 101% and equal to or lower than 110% of the melting point (°C) of the brazing filler metal 50. This improves the diffusibility of the active metal element, facilitating the formation of the second layer 32. When using the brazing filler metal 50 of this embodiment, the heating temperature is preferably equal to or higher than 720°C and equal to or lower than 1000°C, and more preferably equal to or lower than 850°C. The heat treatment furnace used for bonding may be a known furnace, such as a stationary batch furnace, a multi-chamber furnace, a belt conveyor furnace, or a roller hearth kiln.

[0068] Other conditions for bonding include the following: Oxygen concentration: 0.01 volppm or more and 1000 volppm or less, or 0.1 volppm or more and 100 volppm or less Pressure: 0.5kPa or more Holding time: There is no particular limit, but for example, between 3 and 120 minutes

[0069] During heating, a liquid phase must be formed in a portion of the brazing filler metal 50, and the active metal element must be molten within the liquid phase. For example, when a Cu-Mg-Sb alloy is used, in which Ti is the active metal and Sb is the Mg evaporation inhibitor, this state can be achieved by heating the alloy at 720°C or higher. However, if the heating temperature is too high, the Mg evaporation may exceed the effect of the Mg evaporation inhibitor, making it difficult to form a liquid phase or causing voids in the resulting bonding layer 30. Setting the heating temperature to 1000°C or lower can avoid these issues. Applying a pressure of 0.5 kPa or higher can maintain the tight contact between the metal member 10 and the ceramic member 20 via the brazing filler metal 50, thereby increasing the bonding strength between the metal member 10 and the ceramic member 20. There is no particular upper limit to the pressure, but it can be set to, for example, approximately 20 kPa.

[0070] Thereafter, the heated laminate 100' is cooled, resulting in the metal / ceramic bonded body 100 shown in FIG.

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

[0072] (a) The brazing filler metal of this embodiment contains Cu, Mg, at least one Mg evaporation inhibitor selected from Sn, Sb, and Bi, and an active metal element. Therefore, when the brazing filler metal is heated and joined, at least Cu, Mg, and the Mg evaporation inhibitor combine to form an intermetallic compound. This intermetallic compound melts easily at the joining temperature due to a eutectic reaction with Cu, and, due to its bond with the Mg evaporation inhibitor, prevents Mg from evaporating from the eutectic melt during melting. In other words, Mg is bound to the Mg evaporation inhibitor and other elements during the time between melting and solidifying, thereby suppressing its evaporation. As a result, the formation of voids associated with Mg evaporation is reduced in the joining layer 30 obtained by heating the brazing filler metal, allowing for the formation of a dense phase structure and achieving high joining strength.

[0073] (b) Furthermore, the brazing filler metal contains Mg, which can lower the melting point of Cu, and therefore can achieve high bonding strength at a low heating temperature, for example, in the range of 720° C. to 1000° C. Furthermore, the inclusion of Mg can improve wettability to the metal member 10 and the ceramic member 20.

[0074] (c) The brazing filler metal contains 1 at% to 15 at% Mg, 1 at% to 20 at% Mg evaporation inhibitor, and 0.1 at% to 10 at% active metal element, where X at% is the Mg content and Y at% is the Mg evaporation inhibitor content, so that X-6≦Y≦X+6 is satisfied. By including each element in such a content, the effect (a) can be more stably obtained.

[0075] (d) The brazing filler metal preferably contains Cu powder containing Cu and an alloy powder formed from an intermetallic compound containing at least Mg and a Mg evaporation inhibiting element, and is configured in a paste form. By previously converting Mg into an intermetallic compound with the Mg evaporation inhibiting element, evaporation of Mg can be more reliably inhibited when the brazing filler metal is heated. As a result, the joining strength can be more reliably increased.

[0076] (e) The brazing filler metal preferably contains alloy powder such that the content of Mg derived from the alloy powder is 40% or more of the total content of Mg contained in the brazing filler metal, thereby more reliably achieving the effect of (d) above.

[0077] (f) When the brazing filler metal according to this embodiment is used to bond a metal member 10 and a ceramic member 20, the bonding layer 30 is formed by stacking 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. The first layer 31 includes a solid-solution phase in which Cu is solid-solved with at least one of Mg and a Mg evaporation inhibitor, and a compound phase that includes an intermetallic compound containing Cu, Mg, and the Mg evaporation inhibitor, thereby suppressing the generation of voids in the first layer 31. Furthermore, the compound phase 31B further contains the Mg evaporation inhibitor, thereby exhibiting higher strength than a phase that does not contain the Mg evaporation inhibitor. 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 bonding layer 30. The bonding layer 30 having such a phase structure can firmly bond the metal member 10 and the ceramic member 20, achieving high bonding strength.

[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, the voids are 10,000 μm 2 It is preferable that no voids having a circular equivalent diameter of 8 μm or more are observed within any field of view.

[0079] (h) The first layer 31 of the bonding layer 30 preferably has a phase structure in which the solid solution phase 31A forms a continuous phase as a sea phase, which is the parent phase, and the compound phase 31B is dispersed as an island phase. If the compound phase 31B is locally present, the area is prone to breakage when a load is applied to that area. However, by dispersing the compound phase 31B, breakage due to a load can be suppressed, and the bonding strength can be more reliably increased.

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

[0081] (j) In the first layer 31 of the bonding layer 30, the solid solution phase 31A is preferably configured as a continuous phase connecting the second layer 32 and the metal member 10. This allows the first layer 31 to have paths made of the solid solution phase 31A, thereby more reliably increasing the bonding strength.

[0082] (k) When the bonding layer 30 has any one of the phase structures (f) to (j) above, the shear strength of the bonding layer 30 can be increased to 20 MPa or more. Also, the tensile strength of the bonding layer 30 can be increased to 40 MPa or more.

[0083] (l) By forming the bonding layer 30 using a brazing material having Cu as the main phase, it is possible to suppress migration caused by Ag as the main phase. In other words, it is possible to achieve high migration resistance in the bonding layer 30.

[0084] <Other Aspects of the Present Disclosure> Although the embodiments of the present disclosure have been specifically described above, the present disclosure is not limited to the above embodiments and can be modified in various ways without departing from the spirit and scope of the present disclosure.

[0085] In the above-described embodiment, the case where the metal member 10 and the ceramic member 20 are joined has been described, but the present invention 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 different types of metal.

[0086] The metal / ceramic bonded body 100 of this embodiment can be used, for example, as an insulated circuit board. In this case, for example, to form a circuit pattern on the metal member 10, etching may be performed after applying an etching resist to the metal member 10. The type of etching resist is not particularly limited, and known resists such as thermosetting and ultraviolet-curing resists can be used. The method for applying the etching resist is also not particularly limited, and methods such as applying a film-like resist, screen printing, and inkjet coating can be used. Furthermore, after removing unnecessary portions of the metal member 10 from the metal / ceramic bonded body 100 by etching, unnecessary portions of the bonding layer 30 may be further removed. Furthermore, the metal / ceramic bonded body 100 is not limited to use as an insulated circuit board and can be widely used for various applications, such as heat sinks and components of internal combustion engines and power generating machines. In these cases, the same effects as those of the above-described embodiment can be obtained. [Example]

[0087] In this example, the prepared brazing filler metal was used to join a metal member and a ceramic member, or to join two metal members together, and the joining strength of the resulting joined bodies was evaluated.

[0088] (1) Preparation The metal members were a 2.0 mm thick copper material made of oxygen-free copper, a 6.0 mm thick iron alloy material (42ALLOY), and a 6.0 mm thick steel material (SUS304).The ceramic members were a 0.3 mm thick silicon nitride (Si3N4) plate, a 0.3 mm thick silicon carbide (SiC) plate, a 0.3 mm thick AlN plate, a 0.3 mm thick Al2O3 plate, and a 0.3 mm thick diamond plate.

[0089] Powders containing Cu, Mg, a Mg evaporation inhibitor, and an active metal element were prepared as powders for preparing brazing filler metals. Specifically, pure Cu powder was prepared as the Cu-containing powder. Five types of powders containing Mg and Mg evaporation inhibitors were prepared: alloy powders consisting of Cu4MgSn and Cu, alloy powders consisting of CuMgSb and Cu, alloy powders consisting of CuMgBi and Cu, alloy powders consisting of Cu2Mg and Cu, and alloy powders consisting of Cu3Sn and Cu. Pure Mg metal powder was prepared as the Mg-containing powder. Powders containing active metal elements were prepared: TiH2 powder, alloy powders consisting of CuCaSn and Cu, alloy powders consisting of Cu4MgY, Cu2Mg, and Cu, and alloy powders consisting of Cu6Ce, Cu2Mg, and Cu. The average particle size (D50) of each powder was 45 μm or less. The alloy powder was prepared by atomization.

[0090] (2) Preparation of brazing material First, the above powders were mixed so that the contents of Cu, Mg, Mg evaporation inhibitor, and active metal element were as shown in Tables 1 to 6, and then pastes were formed to prepare brazing filler metals (Samples 1 to 42 and 45 to 232). Samples 214 to 232 contain one of the active metal elements Cr, Mo, V, Nb, or Zr, which will be described later. For the paste formation, polyethylene glycol and diethylene glycol monobutyl ether with a molecular weight of 400 or less were used as solvents, and the solvent ratio in the paste was 9 mass%. Sample 43 was prepared in the same manner as Samples 1 to 42, except that the Cu and Mg evaporation inhibitor were not added. Sample 44 was prepared in the same manner as Samples 1 to 42, except that only Mg powder was used. In Tables 1 to 5, the content X represents the Mg content [at %], and the content Y represents the total content [at %] of the Mg evaporation inhibitor.

[0091] [Table 1]

[0092] [Table 2]

[0093] [Table 3]

[0094] [Table 4]

[0095] [Table 5]

[0096] [Table 6]

[0097] (3) Preparation of zygotes Next, for Samples 1 to 213, the prepared paste 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 top of the applied paste film, and a pressure of 8 kPa was applied in the stacking direction, and a pressure of 1.0 × 10 -2 The joined bodies of Samples 1 to 213 were fabricated by heat treatment at 800°C for 60 minutes in a vacuum atmosphere of 0.01 Pa or less (820°C for Samples 43 and 44 only). For Samples 214 to 232, a predetermined molar amount of an active metal element selected from Cr, Mo, V, Nb, and Zr was sputtered onto the intended joining surface of the first member shown in Table 6, and the prepared brazing filler metal paste was applied thereon by screen printing. The brazing filler metal element ratio column in Table 6 indicates the ratio including the sputtered active metal element. Next, the second member was placed directly on top of the applied paste film, and a pressure of 8 kPa was applied in the stacking direction, and a 1.0 x 10 -2 Bonded bodies of samples 214 to 232 were produced by carrying out a heat treatment at 800°C for 60 minutes in a vacuum atmosphere of 0.1 Pa or less.

[0098] (4) Evaluation The phase structure and bonding strength of the bonding layer of the produced bonded bodies were evaluated by the following methods.

[0099] The cross section of the bonding layer of the bonded body was observed to evaluate the phase structure of the bonding layer. Specifically, the first layer was observed in a cross section perpendicular to the bonding surface, and it was found that (1) the solid solution phase and the compound phase had a sea-island structure, (2) paths (continuous phases) consisting of the solid solution phase connecting the second layer and the copper material were secured in the first layer, and (3) the bonding layer had a length of approximately 10,000 μm. 2 It was confirmed that no voids having a circular equivalent diameter of 8 μm or more were observed in the first layer within the field of view.

[0100] The elements dissolved in the solution phase of the first layer were also quantified. Specifically, the content of the elements dissolved in the solution phase was measured using an energy dispersive X-ray analyzer (EDX).

[0101] The bond strength of the bonded structures was evaluated by shear strength tests. Specifically, for the bonded structures, copper materials were machined into cylindrical shapes with a diameter of 3 mm and a height of 2 mm, and the bonding surface of the surrounding ceramic material was exposed to prepare test specimens. Then, 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 bonding surface. The magnitude of the stress at which the bonding layer broke (shear fracture) was measured, and the shear strength of the bonding 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 displacement axis movement speed was 100 μm / s.

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

[0103] The 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 confirmed that it had a phase structure as shown in Figure 6. Figure 6 is an enlarged 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 was formed at the interface of the bonding layer 30 on the ceramic member 20 side. It was also confirmed that a first layer 31 was formed on the second layer 32. It was confirmed that the first layer 31 had a sea-island structure, with compound phase 31B dispersed as an island phase in a solid solution phase 31A of the matrix sea phase. Furthermore, it was confirmed that paths (continuous phases) consisting of the solid solution phase 31A connecting the second layer 32 and the copper material were secured in the first layer 31. It was also confirmed that there were no voids in the first layer 31 with a circle equivalent diameter of 1 μm or more.

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

[0106] Furthermore, as shown in Table 1, it was confirmed that Sample 1 had a shear strength of 186.4 MPa, which translated into a tensile strength of 322.9 MPa. In other words, it was confirmed that high bonding strength could be achieved.

[0107] In Samples 2 to 7, as shown in Table 1, the contents of Mg and Sn in the brazing filler metal were changed from Sample 1, but it was confirmed that a phase structure similar to that of Sample 1 could be achieved. Furthermore, in all samples, like Sample 1, it was confirmed that the solid solution phase 31A was composed of Mg and Sn solid-solubilized in a Cu phase, and the compound phase 31B was composed of Cu4MgSn. The amount of solid solution of Mg was 5.0 at% or less, and the amount of solid solution of Sn was 5.0 at% or less. Furthermore, it was confirmed that the shear strength of all samples was 20 MPa or more, and the converted tensile strength was 40 MPa or more.

[0108] (Samples 8-14) Cross-sectional observation of the bonding layer of Sample 8 confirmed that it had a phase structure as shown in FIG. 7. FIG. 7 is an enlarged partial cross-sectional photograph of the bonding layer of Sample 8. As shown in FIG. 7, it was confirmed that the bonding layer 30 of Sample 8 had a phase structure similar to that of the bonding layer 30 of Sample 1. In particular, it was confirmed that the first layer 31 had a sea-island structure in which the compound phase 31B was dispersed as an island phase in the solid solution phase 31A of the sea phase, which was the parent phase. Furthermore, it was confirmed that paths (continuous phases) consisting of the solid solution phase 31A connecting the second layer 32 and the copper material were secured in the first layer 31. It was also confirmed that there were no voids in the first layer 31 having a circle-equivalent diameter of 1 μm or more.

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

[0110] Furthermore, as shown in Table 1, it was confirmed that Sample 8 had a shear strength of 139.5 MPa, which translated into a tensile strength of 241.6 MPa. In other words, it was confirmed that high bonding strength could be achieved.

[0111] In Samples 9 to 14, as shown in Table 1, the contents of Mg and Sb in the brazing filler metal were changed from Sample 8, but it was confirmed that a phase structure similar to that of Sample 8 could be achieved. In all samples, like Sample 8, it was confirmed that the solid solution phase 31A was composed of Sb solid-solubilized in the Cu phase without Mg solid-solubilized, and the compound phase 31B was composed of CuMgSb. The amount of Sb solid-solubilized was 4.0 at% or less. Furthermore, it was confirmed that the shear strength of all samples was 20 MPa or more, and the converted tensile strength was 40 MPa or more.

[0112] (Samples 15-18) Cross-sectional observation of the bonding layer 30 of Sample 15 confirmed that it had a phase structure as shown in FIG. 8. FIG. 8 is an enlarged partial cross-sectional photograph of the bonding layer 30 of Sample 15. As shown in FIG. 8, it was confirmed that the bonding layer 30 of Sample 15 had a phase structure similar to that of the bonding layer 30 of Sample 1. In particular, it was confirmed that the first layer 31 had a sea-island structure in which the compound phase 31B was dispersed as an island phase in the solid solution phase 31A of the sea phase, which was the parent phase. Furthermore, it was confirmed that paths (continuous phases) consisting of the solid solution phase 31A connecting the second layer 32 and the copper material were secured in the first layer 31. It was also confirmed that there were no voids in the first layer 31 having a circle-equivalent diameter of 1 μm or more.

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

[0114] Furthermore, as shown in Table 1, it was confirmed that Sample 15 had a shear strength of 24.8 MPa, which translated into a tensile strength of 43 MPa. In other words, it was confirmed that high bonding strength could be achieved.

[0115] In Samples 16 to 18, the contents of Mg and Bi in the brazing filler metal were changed from Sample 15 as shown in Table 1, but it was confirmed that a phase structure similar to that of Sample 15 could be achieved. In all samples, like Sample 15, it was confirmed that the solid solution phase 31A was composed of Mg solid-solubilized in the Cu phase without Bi solid-solubilized, and the compound phase 31B was composed of CuMgBi. In all samples, the amount of Mg solid-solubilized was 5.0 at% or less. Furthermore, it was confirmed that the shear strength of all samples was 20 MPa or more, and the converted tensile strength was 40 MPa or more.

[0116] (Samples 19-25) In samples 19 to 25, the contents of Mg, Sn, and Sb were changed from those in samples 1 and 8, but it was confirmed that a phase structure similar to that of samples 1 and 8 could be achieved. In all samples, it was confirmed that a sea-island structure of solid solution phase 31A and compound phase 31B was formed, paths made of solid solution phase 31A connecting second layer 32 and the copper material were formed in first layer 31, and there was not a single void with a circle equivalent diameter of 1 μm or more.

[0117] (Samples 26-33) For Samples 26 to 33, the brazing filler metal was prepared to contain two elements, Sn and Sb, that inhibit Mg evaporation. The bonding layer 30 of Samples 26 to 33 had a phase structure similar to that of Sample 1. It was also confirmed that a sea-island structure of the solid solution phase 31A and the compound phase 31B was formed, and paths consisting of the solid solution phase 31A that connected the second layer 32 and the copper material were formed in the first layer 31, and that there were no voids with a circle equivalent diameter of 1 μm or more.

[0118] Furthermore, EDX measurements confirmed that the compound phase 31B was formed from an intermetallic compound of Cu, Mg, Sn, and Sb. This intermetallic compound was composed of Cu, Mg, Sn, and Sb partially substituted for Cu. On the other hand, the solid solution phase 31A was confirmed to be a Cu phase with Mg, Sn, and Sb dissolved therein.

[0119] Furthermore, as shown in Table 1, it was confirmed that the shear strength of all the samples was 20 MPa or more, and the converted tensile strength was 40 MPa or more.

[0120] (Samples 34-39) For Samples 34 to 39, as shown in Table 1, the brazing filler metal was prepared and joined bodies were fabricated in the same manner as for Sample 1, except that the type of ceramic member was changed from Si3N4 to SUS304, AlN, Al2O3, SiC or diamond.

[0121] The bonding layer 30 of samples 34 to 39 was confirmed to have a phase structure similar to that of sample 1. It was also confirmed that an island-sea structure of the solid solution phase 31A and the compound phase 31B was formed, paths made of the solid solution phase 31A connecting the second layer 32 and the copper material were formed in the first layer 31, and there was not a single void with a circle equivalent diameter of 1 μm or more.

[0122] Furthermore, as shown in Table 1, it was confirmed that the shear strength of all the samples was 20 MPa or more, and the converted tensile strength was 40 MPa or more.

[0123] (Samples 40-42) In Samples 40 to 42, an iron alloy material (42ALLOY) was used as the metal member and a Si3Ni4 substrate was used as the ceramic member, as shown in Table 1. It was confirmed that all samples had a phase structure similar to that of Sample 1 and the like, and that a predetermined bonding strength was obtained.

[0124] (Samples 43 and 44) Sample 43, which used a brazing filler metal containing Mg and Ti, and Sample 44, which used a brazing filler metal containing only Mg, had a shear strength of less than 20 MPa and a tensile strength of less than 40 MPa, as shown in Table 1, and it was confirmed that practical bonding strength was not achieved (they were essentially unbonded). Note that these samples did not have a bonding strength that could withstand processing for cross-sectional structural observation, so it was not possible to observe the bonding layer in a cross section perpendicular to the bonding surface.

[0125] (Samples 45-232) As shown in Tables 2 to 6, it was confirmed that Samples 45 to 232 all had a shear strength of 20 MPa or more, and the converted tensile strength was 40 MPa or more.

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

[0127] (Appendix 1) Cu and 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. It is a brazing material.

[0128] (Appendix 2) In Appendix 1, preferably, The content of the Mg is 1 at% or more and 15 at% or less, the content of the first element is 1 at% or more and 20 at% or less, and the content of the second element is 0.1 at% or more and 10 at% or less, and when the content of the Mg is X at% and the content of the first element is Y at%, X-6≦Y≦X+6.

[0129] (Appendix 3) In Supplementary Note 1 or Supplementary Note 2, preferably, The paste-like composition contains Cu powder containing Cu and alloy powder having an intermetallic compound containing at least Mg, the first element, and the second element.

[0130] (Appendix 4) a first member made of metal; a second member joined to the first member and made of the same or different metal or ceramic as the first member; a bonding layer formed on a bonding surface between the first member and the second member, The bonding layer is Cu and 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. It is a zygote.

[0131] (Appendix 5) In Appendix 4, preferably, The bonding layer is a first layer that forms an interface with the first member and includes a solid solution phase in which Mg and at least one of the first element are solid-solved in Cu, and a compound phase that includes an intermetallic compound containing Cu, Mg, and the first element; The second layer forms an interface with the second member, contains a compound of the second element, and is in contact with the first layer.

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

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

[0134] (Appendix 8) In any one of Supplementary Notes 4 to 7, preferably, The bonding layer has a shear strength of 20 MPa or more.

[0135] (Appendix 9) In any one of Supplementary Notes 4 to 8, preferably, The bonding layer has a tensile strength of 40 MPa or more.

[0136] (Appendix 10) A method for manufacturing a brazing filler metal used to join a first member made of metal to a second member made of the same or different metal as the first member, or made of ceramics, comprising: 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 brazing filler metal. Manufacturing method of brazing filler metal.

[0137] (Appendix 11) an arrangement step of arranging a first member made of metal and a second member made of the same or different metal as the first member or a ceramic so as to be laminated via a brazing material; a heating step of heating and holding the laminate of the first member and the second member while applying pressure in the lamination direction, The brazing material used is 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 bonded body.

[0138] (Appendix 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 state.

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

[0140] 100 Metal / ceramic joints 100' laminate 10 Metal member (first member) 10s joint surface 20 Ceramic member (second member) 20s joint surface 30 Bonding layer 31 1st layer 31A Solid solution phase 31B Compound phase 32 2nd layer 50 Brazing filler metal

Claims

1. 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, V, Nb, Cr, Mo, Y, Ca, and Ce; the balance being Cu, the Mg content is 2.0 at% or more and 15.0 at% or less, and when the Mg content is X at% and the total content of the first element is Y at%, 2.2≦Y≦19.7 and X−6≦Y≦X+6 are satisfied; When only Ti is contained as the second element, the content of Ti is 2.6 at% or more and 9.2 at% or less, when the second element includes any one selected from the group consisting of Zr, V, Nb, Cr, and Mo and does not include Y, Ca, and Ce, the content of Ti is 0 at% or more and 3.9 at% or less, and the content of any one selected from the group consisting of Zr, V, Nb, Cr, and Mo is 0.4 at% or more and 0.7 at% or less, when the second element includes Ti and any one selected from the group consisting of Y, Ca, and Ce, and does not include Zr, V, Nb, Cr, and Mo, the content of Ti is 2.6 at% or more and 3.9 at% or less, and the content of any one selected from the group consisting of Y, Ca, and Ce is 1.5 at% or more and 1.7 at% or less, When only Y is contained as the second element, the content of Y is 3.5 at%. Brazing material.

2. The alloy powder contains Cu powder containing Cu and an intermetallic compound containing at least Mg, the first element, and the second element, and is formed into a paste. The brazing filler metal according to claim 1.

3. a first member made of metal; a second member joined to the first member and made of the same or different metal or ceramic as the first member; a bonding layer formed on a bonding surface between the first member and the second member, The bonding layer is 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, V, Nb, Cr, Mo, Y, Ca, and Ce; the balance being Cu, the Mg content is 2.0 at% or more and 15.0 at% or less, and when the Mg content is X at% and the total content of the first element is Y at%, 2.2≦Y≦19.7 and X−6≦Y≦X+6 are satisfied; When only Ti is contained as the second element, the content of Ti is 2.6 at% or more and 9.2 at% or less, when the second element includes any one selected from the group consisting of Zr, V, Nb, Cr, and Mo and does not include Y, Ca, and Ce, the content of Ti is 0 at% or more and 3.9 at% or less, and the content of any one selected from the group consisting of Zr, V, Nb, Cr, and Mo is 0.4 at% or more and 0.7 at% or less, when the second element includes Ti and any one selected from the group consisting of Y, Ca, and Ce, and does not include Zr, V, Nb, Cr, and Mo, the content of Ti is 2.6 at% or more and 3.9 at% or less, and the content of any one selected from the group consisting of Y, Ca, and Ce is 1.5 at% or more and 1.7 at% or less, When the second element contains only Y, the content of Y is 3.5 at%. zygote.

4. The bonding layer is a first layer that forms an interface with the first member and includes a solid solution phase in which at least one of Mg and the first element is solid-solved in Cu, and a compound phase that includes an intermetallic compound containing Cu, Mg, and the first element; a second layer that forms an interface with the second member, that contains a compound of the second element, and that is in contact with the first layer; The bonded body according to claim 3 .

5. When the first layer is observed in a cross section perpendicular to the bonding surface, the number of voids having a circular equivalent diameter of 8 μm or more is 10,000 μm or more. ２ less than one per The bonded body according to claim 4.

6. the first layer has a path made of the solid solution phase connecting the second layer and the first member; The bonded body according to claim 4.

7. The shear strength of the bonding layer is 20 MPa or more. The bonded body according to claim 3 or 4.

8. The tensile strength of the bonding layer is 40 MPa or more. The bonded body according to claim 3 or 4.

9. A method for manufacturing a brazing filler metal used to join a first member made of metal to a second member made of the same or different metal as the first member, or made of ceramics, comprising: The method includes a step of mixing a powder containing Mg, at least one first element selected from the group consisting of Sn, Sb, and Bi, at least one second element selected from the group consisting of Ti, Zr, V, Nb, Cr, Mo, Y, Ca, and Ce, with the balance being Cu, with a solvent to obtain a paste-like brazing filler metal; In the brazing filler metal, the content of the Mg is 2.0 at% or more and 15.0 at% or less, and when the content of the Mg is X at% and the total content of the first element is Y at%, 2.2≦Y≦19.7 and X−6≦Y≦X+6 are satisfied; When only Ti is contained as the second element, the content of Ti is 2.6 at% or more and 9.2 at% or less, when the second element includes any one selected from the group consisting of Zr, V, Nb, Cr, and Mo and does not include Y, Ca, and Ce, the content of Ti is 0 at% or more and 3.9 at% or less, and the content of any one selected from the group consisting of Zr, V, Nb, Cr, and Mo is 0.4 at% or more and 0.7 at% or less, when the second element includes Ti and any one selected from the group consisting of Y, Ca, and Ce, and does not include Zr, V, Nb, Cr, and Mo, the content of Ti is 2.6 at% or more and 3.9 at% or less, and the content of any one selected from the group consisting of Y, Ca, and Ce is 1.5 at% or more and 1.7 at% or less, When only Y is contained as the second element, the content of Y is 3.5 at%. Manufacturing method of brazing filler metal.

10. an arrangement step of arranging a first member made of metal and a second member made of the same or different metal as the first member or a ceramic so as to be laminated via a brazing material; a heating step of heating and holding the laminate of the first member and the second member while applying pressure in a stacking direction, The brazing material contains Mg, at least one first element selected from the group consisting of Sn, Sb, and Bi, at least one second element selected from the group consisting of Ti, Zr, V, Nb, Cr, Mo, Y, Ca, and Ce, and the balance is Cu, In the brazing filler metal, the content of the Mg is 2.0 at% or more and 15.0 at% or less, and when the content of the Mg is X at% and the total content of the first element is Y at%, 2.2≦Y≦19.7 and X−6≦Y≦X+6 are satisfied; When only Ti is contained as the second element, the content of Ti is 2.6 at% or more and 9.2 at% or less, when the second element includes any one selected from the group consisting of Zr, V, Nb, Cr, and Mo and does not include Y, Ca, and Ce, the content of Ti is 0 at% or more and 3.9 at% or less, and the content of any one selected from the group consisting of Zr, V, Nb, Cr, and Mo is 0.4 at% or more and 0.7 at% or less, when the second element includes Ti and any one selected from the group consisting of Y, Ca, and Ce, and does not include Zr, V, Nb, Cr, and Mo, the content of Ti is 2.6 at% or more and 3.9 at% or less, and the content of any one selected from the group consisting of Y, Ca, and Ce is 1.5 at% or more and 1.7 at% or less, When only Y is contained as the second element, the content of Y is 3.5 at%. A method for manufacturing a bonded body.

11. 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 state. The method for producing the bonded body according to claim 10 .

12. In the heating step, the laminate is heated at a temperature of 720°C or higher and 1000°C or lower. The method for producing the bonded body according to claim 10 or 11.

Images