Joining brazing material and joint

Abstract

To provide a brazing filler metal for joining that can join ceramic and metal with high strength, and a joined body.SOLUTION: A brazing filler metal for joining, which joins ceramic and metal, contains antimony (Sb) of 31 wt% or more and less than 60 wt%, and titanium (Ti) of 1 wt% or more and 5 wt% or less, and a remainder comprising Cu and inevitable impurities.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a brazing filler metal for joining and a joined body.

Background Art

[0002] Conventionally, as a circuit board used in a semiconductor device or the like, a joined body in which a ceramic having heat resistance and insulation and a conductive metal are joined is known (see, for example, Patent Documents 1 and 2). In Patent Documents 1 and 2, a brazing filler metal is used for joining a ceramic and a metal. At this time, as the brazing filler metal, a Cu-Mg-Ti alloy in which titanium (Ti) or a Ti-Cu alloy is added to a copper (Cu)-magnesium (Mg) alloy, or a material containing Cu and a eutectic element that eutectically reacts with this Cu is used. Here, in Patent Document 2, when antimony (Sb) is used as the eutectic element, it is described that the mass% of Sb in the brazing filler metal is 56% or more and 90% or less.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, Mg has a high vapor pressure, and in Reference Document 1, when Mg evaporation occurs in a joining process exceeding 500°C, there is a risk of joining failure. Further, Sb is known to be a brittle material, and in Patent Document 2, the addition amount of Sb to Cu is large, and brittle fracture is likely to occur at the joining interface.

[0005] The present invention has been made in view of the above, and aims to provide a bonding brazing material and a bonded body that can bond ceramics and metals with high strength. [Means for solving the problem]

[0006] To solve the above-mentioned problems and achieve the objective, the brazing material for joining ceramics and metals according to the present invention is a brazing material for joining ceramics and metals, and is characterized by containing 31% to less than 60% by weight of antimony (Sb), 1% to 5% by weight of titanium (Ti), and the remainder consisting of Cu and unavoidable impurities.

[0007] Furthermore, the brazing material for joining according to the present invention is characterized in that, in the above invention, it contains at least one selected from tin (Sn) and indium (In) in a total amount of 1% by weight or more and less than 30% by weight.

[0008] Furthermore, the joint according to the present invention is characterized by comprising: ceramics; a metal; and a joining brazing material for joining the ceramics and the metal, the joining brazing material comprising 31% to less than 60% by weight of antimony (Sb), 1% to 5% by weight of titanium (Ti), and the remainder being Cu and unavoidable impurities. [Effects of the Invention]

[0009] According to the present invention, ceramics and metals can be joined with high strength. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 shows the configuration of a joint according to one embodiment of the present invention. [Figure 2] Figure 2 shows ultrasonic flaw detection images of the joint interface of the joint obtained in the example. [Figure 3] Figure 3 is an image obtained by applying a binarization process to the ultrasonic flaw detection image shown in Figure 2. [Figure 4]Figure 4 is a diagram illustrating the test specimen used in the tensile test. [Figure 5] Figure 5 shows the bonding rates in Examples 1 to 7. [Figure 6] Figure 6 shows the bonding rates in Comparative Examples 1 to 6. [Figure 7] Figure 7 shows the tensile shear loads in Examples 1, 4-7. [Modes for carrying out the invention]

[0011] Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as "embodiments") will be described with reference to the attached drawings. Note that the drawings are schematic, and the relationship between the thickness and width of each part, the ratio of the thickness of each part, etc., may differ from reality, and there may be parts where the dimensional relationships and ratios differ between drawings.

[0012] (Embodiment) Figure 1 shows the configuration of a bonded body according to one embodiment of the present invention. The bonded body 1 is used, for example, as a circuit board in a semiconductor device. The bonded body 1 comprises a ceramic layer 11 formed using ceramics, a conductive layer 12 formed using a conductive material, and a bonding layer 13 provided between the ceramic layer 11 and the conductive layer 12 to bond the two together.

[0013] The ceramic layer 11 is, for example, in the form of a plate. The ceramic layer 11 is formed using, for example, Si3N4.

[0014] The conductive layer 12 is formed using a conductive metal such as copper (Cu).

[0015] The bonding layer 13 contains antimony (Sb) as a first additive in an amount of 31% by weight or more and less than 60% by weight, titanium (Ti) as a second additive in an amount of 1% by weight or more and 5% by weight or less, and the balance consists of Cu and inevitable impurities. Further, the bonding layer 13 may contain at least one selected from tin (Sn) and indium (In) as a third additive in a total amount of 1% by weight or more and less than 30% by weight.

[0016] Specifically, the bonding layer 13 has an active metal layer and an alloy layer. In the bonding layer 13, the active metal layer and the alloy layer are provided from the side of the ceramics layer 11. The active metal layer contains titanium (Ti) which is the second additive. The alloy layer contains at least Cu and Sb which is the first additive. The alloy layer may contain the third additive in addition to the first additive.

[0017] In the embodiment of the present invention described above, the bonding layer 13 for bonding the ceramics layer 11 and the conductive layer 12 contains antimony (Sb) as a first additive in an amount of 31% by weight or more and less than 60% by weight, titanium (Ti) as a second additive in an amount of 1% by weight or more and 5% by weight or less, and the balance consists of Cu and inevitable impurities. Here, by the bonding layer 13 containing Ti and Sb within the above ranges, Ti improves the reactivity with the ceramics, and Sb eutectifies with Cu. Thereby, the ceramics and the metal can be bonded with high strength.

[0018] Further, in the embodiment of the present invention, by the bonding layer 13 containing tin (Sn) and / or indium (In), the mechanical properties of the bonded body can be improved.

Example

[0019] Hereinafter, examples of the bonded body according to the present invention will be described. Note that the present invention is not limited to these examples.

[0020] (Example 1) Joints were fabricated by joining ceramics and metal using brazing materials of the compositions shown in Table 1. Each brazing material contained 31% by weight of Sb, 2% by weight of Ti, with the remainder being Cu and unavoidable impurities. A Si3N4 ceramic layer measuring 25 mm in length, 25 mm in width, and 0.32 mm in thickness, and a C1020 copper alloy conductive layer measuring 25 mm in length, 25 mm in width, and 0.5 mm in thickness, were joined using a brazing material with the composition of Example 1. Specifically, a paste-like brazing material was applied to the central region (15 mm x 15 mm) of the copper alloy, and the material was fabricated in a vacuum heat treatment furnace under a vacuum atmosphere with a load of 2.5 kgf and a surface pressure of 0.04 MPa. The temperature conditions were as follows: heating at 10°C / min, 600°C (first soaking temperature) for 30 minutes, 720°C (second soaking temperature) for 1 hour, then cooling to 100°C at 3°C / min, followed by cooling by nitrogen sealing.

[0021] <Feasibility of connection evaluation> The feasibility of joining the components was evaluated visually by assessing whether brazing was possible, as follows: ○: Joined △: Joined, but the joint layer has damage such as cracks. ×: Not properly joined

[0022] <Evaluation of bonding ratio> For joints with a joint feasibility evaluation of ○ and △, the joint state of the joint interface was imaged using ultrasonic testing (SAT), and the joint ratio was calculated by binarizing the captured images. In this process, the area where the brazing material was applied (15 × 15 mm: area R in Figures 2 and 3) was set to 100%, and the joint ratio was defined as the percentage of the area where the brazing material spread. Figure 2 is an ultrasonic testing image of the joint interface of the joint obtained in the example. Figure 3 is an image obtained by applying a binarization process to the ultrasonic testing image shown in Figure 2. After obtaining a SAT image like the one in Figure 2, this SAT image is binarized to obtain the binarized image shown in Figure 3. In Figure 3, lighter colored areas indicate that the joint is joined (joining OK), and darker colored areas indicate that the joint is not joined (joining NG). The joining rate is calculated by determining the area of ​​the lighter colored area, which is 225 mm². 2 The ratio to the total was defined as the bonding rate.

[0023] <Tensile Test> First, a test specimen for tensile testing was prepared. Figure 4 is a diagram illustrating the test specimen used for tensile testing. The test specimen consists of two copper plates (copper plates 101 and 102) made of C1020, measuring 25 mm in length, 80 mm in width, and 0.5 mm in thickness, to which a ceramic plate 103 made of Si3N4, measuring 25 mm in length, 25 mm in width, and 0.32 mm in thickness, is joined via brazing material. Here, brazing materials 104 and 105 are applied to two regions of the ceramic plate, measuring 25 mm in length and 10 mm in width, respectively, and copper plates 101 and 102 are bonded to these regions. After that, a tungsten weight is placed on top to set the surface pressure to 0.04 MPa and solidify the bonded surface. The copper plates 101 and 102 of the prepared test specimen were each grasped and moved in a direction that moved them apart from each other. The test specimen was then pulled, and the load it could withstand until it broke was measured as the tensile shear load.

[0024] Table 1 shows the composition of the brazing material and the test results in Example 1. [Table 1]

[0025] (Example 2) Example 2 is the same as Example 1 except that the Sb content in the brazing material composition was 40% by weight. The composition of the brazing material and the test results in Example 2 are shown in Table 1.

[0026] (Example 3) Example 3 is the same as Example 1 except that the Sb content in the brazing material composition was 50% by weight. The composition of the brazing material and the test results in Example 3 are shown in Table 1.

[0027] (Example 4) Example 4 is the same as Example 1 except that 5% by weight of Sn was added to the composition of the brazing material. The composition of the brazing material and the test results in Example 4 are shown in Table 1.

[0028] (Example 5) Example 5 is the same as Example 1 except that 20% by weight of Sn is added to the composition of the brazing material and the second soaking temperature is set to 3 hours. The composition of the brazing material and the test results in Example 5 are shown in Table 1.

[0029] (Example 6) Example 6 is the same as Example 1 except that 5% by weight of In was added to the composition of the brazing material. The composition of the brazing material and the test results in Example 6 are shown in Table 1.

[0030] (Example 7) Example 7 is the same as Example 1 except that 20% by weight of In is added to the composition of the brazing material and the second soaking temperature is set to 4 hours. The composition of the brazing material and the test results in Example 7 are shown in Table 1.

[0031] (Comparative Example 1) Comparative Example 1 is the same as Example 1 except that the composition of the brazing material had a Sb content of 20% by weight and the second soaking temperature was 950°C. The composition of the brazing material and the test results for Comparative Example 1 are shown in Table 1.

[0032] (Comparative Example 2) Comparative Example 2 is the same as Example 1 except that the Sb content in the brazing material composition was 60% by weight. The composition of the brazing material and the test results for Comparative Example 2 are shown in Table 1.

[0033] (Comparative Example 3) Comparative Example 3 is the same as Example 1 except that the Sb content in the brazing material composition was 90% by weight. The composition of the brazing material and the test results for Comparative Example 3 are shown in Table 1.

[0034] (Comparative Example 4) Comparative Example 4 is the same as Example 1 except that 1% by weight of Mg is added to the composition of the brazing material and the heating environment at the second soaking temperature is a nitrogen atmosphere. The composition of the brazing material and the test results for Comparative Example 4 are shown in Table 1.

[0035] (Comparative Example 5) Comparative Example 5 is the same as Example 1 except that 3% by weight of Mg is added to the composition of the brazing material and the heating environment at the second soaking temperature is a nitrogen atmosphere. The composition of the brazing material and the test results for Comparative Example 5 are shown in Table 1.

[0036] (Comparative Example 6) Comparative Example 6 is the same as Example 1 except that 5% by weight of Mg is added to the composition of the brazing material and the heating environment at the second soaking temperature is a nitrogen atmosphere. The composition of the brazing material and the test results for Comparative Example 6 are shown in Table 1.

[0037] (Comparative Example 7) Comparative Example 7 is the same as Example 1 except that 10% by weight of Mg is added to the composition of the brazing material and the heating environment at the second soaking temperature is a nitrogen atmosphere. The composition of the brazing material and the test results for Comparative Example 7 are shown in Table 1.

[0038] (Comparative Example 8) Comparative Example 8 is the same as Example 1 except that the composition of the brazing material contains 20% by weight of Mg instead of Sb, and 5% by weight of Ti, and the second soaking temperature is 830°C and the heating environment at the second soaking temperature is a nitrogen atmosphere. The composition of the brazing material and the test results for Comparative Example 8 are shown in Table 1.

[0039] (Comparative Example 9) Comparative Example 9 is the same as Example 1 except that the composition of the brazing material contains 30% by weight of Mg instead of Sb, and 5% by weight of Ti, and the second soaking temperature is 700°C and the heating environment at the second soaking temperature is a nitrogen atmosphere. The composition of the brazing material and the test results for Comparative Example 9 are shown in Table 1.

[0040] (Comparative Example 10) Comparative Example 10 is the same as Example 1 except that the composition of the brazing material contains 40% by weight of Mg instead of Sb, and 5% by weight of Ti, and the second soaking temperature is 620°C and the heating environment at the second soaking temperature is a nitrogen atmosphere. The composition of the brazing material and the test results for Comparative Example 10 are shown in Table 1.

[0041] (Comparative Example 11) Comparative Example 11 is the same as Example 1 except that the composition of the brazing material is the same as Example 1, except that Sb is replaced with 4 wt% Ni, 15 wt% Sn, and 5 wt% phosphorus (P), and the second soaking temperature is 670°C. The composition of the brazing material and the test results for Comparative Example 11 are shown in Table 1.

[0042] In Examples 1-7, it was confirmed that ceramics and metal (Cu) could be joined using brazing material. On the other hand, in Comparative Examples 1, 7-11, it was confirmed that joining could not be achieved with the respective brazing material compositions. In Comparative Examples 2 and 3, although joining was achieved, cracks occurred in the brazing material.

[0043] Figure 5 shows the bonding rates in Examples 1 to 7. Figure 6 shows the bonding rates in Comparative Examples 1 to 6. In Examples 1 to 7, the bonding was spread and achieved a coverage of 182% or more. On the other hand, Comparative Examples 4 to 6 showed a bonding rate of 100%, indicating no spreading. In Comparative Examples 2 and 3, although the bonding rate was high, cracks occurred in the brazing material.

[0044] Figure 7 shows the tensile shear load ratios in Examples 1, 4-7. As shown in Table 1 and Figure 7, tensile shear loads of 613 N or more were obtained in Examples 1, 4-7, and each showed a high bonding rate.

[0045] While embodiments for carrying out the present invention have been described so far, the present invention should not be limited to the embodiments described above.

[0046] Thus, the present invention may include various embodiments not described herein, and various design modifications can be made without departing from the technical idea specified by the claims.

[0047] As described above, the brazing material for joints and the joints according to the present invention are suitable for joining ceramics and metals with high strength. [Explanation of Symbols]

[0048] 1 zygote 11 Ceramic Layers 12. Conductive layer 13 Bonding layer

Claims

1. A bonding brazing material for joining ceramics and metals, It contains 31% to less than 60% by weight of antimony (Sb), 1% to 5% by weight of titanium (Ti), and the remainder consists of Cu and unavoidable impurities. A bonding brazing material characterized by the following features.

2. It contains at least one element selected from tin (Sn) and indium (In) in a total amount of 1% by weight or more and less than 30% by weight. The bonding brazing material according to feature 1.

3. Ceramics and, Metal and, A brazing material for joining the ceramics and the metal, comprising 31% to less than 60% by weight of antimony (Sb), 1% to 5% by weight of titanium (Ti), and the remainder consisting of Cu and unavoidable impurities, A joint characterized by having the following features.

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