Active metal brazing material and method for manufacturing joined body using the same

Abstract

To provide an active metal brazing material which can suppress variation in joining.SOLUTION: An active metal brazing material contains one or two kinds of Ti component particles, CuSn alloy particles and CuIn alloy particles, wherein the Ti component particles are composed of one or more kinds of Ti particles and Ti hydride particles, the CuSn alloy particles are composed of Cu and Sn, when the total of Cu and Sn is 100 pts.mass, Cu is 30 pts.mass or more and 80 pts.mass or less, and Sn is 20 pts.mass or more and 70 pts.mass or less, the CuIn alloy particles are composed of Cu and In, and when the total of Cu and In is 100 pts.mass, Cu is 30 pts.mass or more and 80 pts.mass or less, and In is 20 pts.mass or more and 70 pts.mass or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The embodiments described below are generally directed to a method for manufacturing an active metal brazing material and a bonded body using the same. Regarding. [Background technology]

[0002] A bonded body in which a ceramic substrate and a copper plate are bonded together is used in a ceramic circuit board. For example, in Japanese Patent No. 6789955 (Patent Document 1), an active metal brazing material is used to form ceramic The active metal brazing material in Patent Document 1 is Ag-Cu-Sn In Patent Document 1, a method for controlling the size and hardness of the protruding portion of the bonding layer is used. By doing so, we are able to provide ceramic circuit boards with excellent TCT. In Patent Publication No. 345054 (Patent Document 2), Ag-C-In-Ti alloy powder and Ti powder are mixed. The ceramic circuit board of Patent Document 2 has been developed to improve the bonding strength. The top and bottom swells have been reduced. On the other hand, active metal brazing materials using Ag are expensive, so active metal brazing materials that do not use Ag are For example, International Publication No. WO2022 / 075409 (Patent Document) In Patent Document 3, a Cu-Sn-Ti brazing material that does not contain Ag is used. By forming multiple CuSn alloys in the bonding layer, the bonding strength is improved and warpage is reduced. This has been achieved. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6789955 [Patent Document 2] Patent No. 4345054 [Patent Document 3] International Publication No. 2022 / 075409 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 2, the heat bonding process is carried out in a vacuum furnace. This is done in a batch process, so vacuum furnaces are sometimes called batch furnaces. In Patent Document 3, a continuous furnace is used for the heat bonding process. Although the continuous furnace is designed to achieve the highest possible results, there is variation between lots. The area is divided into a bonding zone and a cooling zone. In these heating bonding methods, there was a variation in the amount of heat applied to the bonded objects. In the case of the present invention, since a sealed space is created, the heat applied to the bonded body is less likely to vary. This is to address these issues, and even if the joining process is carried out using a continuous furnace, The present invention aims to provide an active metal brazing material that can reduce variations in bonding strength. [Means for solving the problem]

[0005] The active metal brazing material according to the embodiment is composed of Ti component particles and CuSn alloy particles or CuIn An active metal brazing material containing one or two of the alloy particles, wherein the Ti component particles are , Ti particles or Ti hydride particles, and CuSn alloy particles are composed of Cu and S. When the total of Cu and Sn is 100 parts by mass, Cu is 30 parts by mass or more and 80 parts by mass or less. parts by mass or less, Sn is in the range of 20 parts by mass or more and 70 parts by mass or less, and the CuIn alloy particles are The total of Cu and In is 100 parts by mass, and Cu is 30 parts by mass or more. 0 parts by mass or less, and In in the range of 20 parts by mass or more and 70 parts by mass or less. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 2 is a diagram showing an example of a laminate according to an embodiment. [Figure 2] 5A to 5C are diagrams showing an example of a bonding method for a bonded body according to an embodiment. [Figure 3] FIG. 2 is a view showing an example of a bonded body according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] The active metal brazing material according to the embodiment is composed of Ti component particles and CuSn alloy particles or CuIn An active metal brazing filler metal containing one or two types of alloy particles, The Ti component particles are at least one of Ti particles and Ti hydride particles, The CuSn alloy particles are composed of Cu and Sn, and when the total of Cu and Sn is 100 parts by mass, Cu in the range of 30 parts by mass to 80 parts by mass, Sn in the range of 20 parts by mass to 70 parts by mass can be, The CuIn alloy particles are composed of Cu and In, and when the total of Cu and In is 100 parts by mass, Cu in the range of 30 parts by mass to 80 parts by mass, In in the range of 20 parts by mass to 70 parts by mass It is characterized by the fact that

[0008] The active metal brazing material according to the embodiment is composed of Ti component particles and CuSn alloy particles or CuIn It contains one or two of the alloy particles. "Ti component particles + CuIn alloy particles" or "Ti component particles + CuS This indicates that the alloy has a combination of "n alloy particles + CuIn alloy particles." The Ti component particles are at least one of Ti particles and Ti hydride particles. Ti particles refer to metallic Ti (titanium) particles, and Ti hydride particles refer to TiH2 particles. The Ti particles or Ti hydride particles may contain unavoidable impurities. The CuSn alloy particles are an alloy made of Cu (copper) and Sn (tin). The gold particles contain 30 to 80 parts by mass of Cu when the total of Cu and Sn is 100 parts by mass. In the following, the Sn content is within the range of 20 to 70 parts by mass. Note that CuSn alloys are not permitted. It may contain impurities.

[0009] The CuIn alloy particles are an alloy made of Cu (copper) and In (indium). The CuIn alloy contains 30 to 80 parts by mass of Cu when the total of Cu and In is 100 parts by mass. The CuIn alloy is in the range of 20 to 70 parts by mass. It may contain unavoidable impurities. The CuSn alloy particles or CuIn alloy particles having a predetermined composition are pre-alloyed. Therefore, the melting reaction is uniform. Even if there is some unevenness, a uniform bonding layer can be formed. Even if this occurs, the variation in bonding strength can be suppressed. In addition, CuSn alloys or CuIn alloys are mixed with a specified composition, solid solutions, and Various compounds such as intermetallic compounds can be used.

[0010] CuSn alloys form intermetallic compounds such as Cu6Sn, Cu3Sn, and Cu6Sn5. These intermetallic compounds contain 30 parts by mass or more and 80 parts by mass or less of Cu and 20 parts by mass or less of Sn. By satisfying this composition, the melting point of Variation can be suppressed. CuIn alloys include Cu7In3, Cu7In4, Cu9In4, Cu 1.1 In 0.9 , Cu 0.8 In 0.2 These intermetallic compounds form intermetallic compounds such as Cu and In is in the range of 20 parts by mass or more and 70 parts by mass or less. By satisfying this composition, it is possible to suppress variations in melting point. By adding CuSn alloy or CuIn alloy in advance, This allows the active metal brazing material to melt uniformly. For this reason, the joining process is carried out in a continuous furnace. Even if the bonding is uneven, it is possible to suppress the bonding variation. The Cu-In-Ti quaternary alloy has a complex composition, so it is important to make the melting uniform. In addition, as in Patent Document 1 and Patent Document 3, when Cu powder and Sn powder are added individually, When mixing the ingredients together, the dissolution tends to vary depending on how they are mixed. However, this is not necessarily suitable for joining processes where the temperature inside a continuous furnace is prone to fluctuating. Not yet.

[0011] The average particle size of the Ti component particles and the CuSn alloy particles is 20 μm or more. It is preferable that the average particle size of the Ti component particles is greater than the average particle size of the CuSn alloy. The average particle size of the particles is preferably in the range of 2 μm to 20 μm. Median diameter D 50 shall be used. The fact that the average particle size of CuSn alloy particles is greater than the average particle size of Ti component particles means that the CuSn alloy This shows that the gold particles are larger than the Ti particles. In comparison, the CuSn alloy has a lower melting point. The CuSn alloy with larger particles melts first. This allows the reaction to be homogenized. After the CuSn alloy is melted, the Ti component is transferred to the ceramic. By reacting with the Cu substrate, the reaction within the bonding layer can be made uniform. The average particle size of the Sn alloy particles is preferably 20 μm or less. If the diameter exceeds 20 μm, the mixing with the Ti component may become uneven. The average particle size of the uSn alloy particles is 2 μm or more and 20 μm or less, and further 4 μm or more and 10 μm or less. The following ranges are preferred: The average particle size of the Ti component particles and the CuIn alloy particles is 20 μm or more. It is preferable that the average particle size of the CuIn alloy particles is greater than the average particle size of the Ti component particles. The average particle size of the particles is preferably in the range of 2 μm to 20 μm. By controlling the particle size, the same effect as that of the CuSn alloy can be obtained.

[0012] The active metal brazing material contains 100 mass% of Ti component particles and CuSn alloy particles. When the Ti component particles are 1 mass % or more and 15 mass % or less, the CuSn alloy particles are 85 mass % or less. The active metal brazing material is preferably in the range of 0.1% to 99% by mass. It reacts with the ceramic substrate. In the case of nitride ceramic substrate, titanium nitride (TiN) In the case of an oxide ceramic substrate, a titanium oxide (TiO2) layer is formed. This improves the bonding strength. The active metal brazing material preferably contains Ti particles in an amount of 6 mass % or more. By setting the particle content within the range of 6% by mass to 15% by mass, the variation in bonding temperature can be reduced. Even if there is adhesion, good bonding can be achieved. Ti particles are less than 1 mass% If the amount of active metal is small, the bonding strength may decrease. If the Ti content exceeds 15 mass %, the bonding strength may decrease. When the total of the particles and CuSn alloy particles is 100 mass%, the Ti component particles are 1 mass%. It is more preferable that the content is in the range of 6% by mass or more and 15% by mass or less, and more preferably in the range of 6% by mass or more and 14% by mass or less. stomach. In addition, the active metal brazing material contains 100 mass % of Ti component particles and CuIn alloy particles in total. When the Ti component particles are mixed, the Ti component particles are mixed in an amount of 1 mass % to 15 mass % and the CuIn alloy particles are mixed in an amount of 85 mass %. The CuIn alloy particles are also preferably in the range of CuS or more and 99% by mass or less. As with n-alloy particles, it is effective to control the amount of mixture.

[0013] The active metal brazing material preferably contains carbon particles in an amount of 0.1 mass % to 2 mass %. By including carbon particles, the active metal brazing material (including active metal brazing material paste) This allows for easy application onto ceramic substrates. In addition, when carbon particles are included, the ratio of Ti component particles + CuSn alloy particles + carbon particles = 1 In the case of CuIn alloy particles, the content is calculated as 00 mass%. The content is calculated assuming that CuIn alloy particles + carbon particles = 100 mass %. In addition to the above components, active metal brazing materials also contain silver (Ag), tungsten (W), molybdenum (Mo), etc. One or more elements selected from the group consisting of ammonium (Al), magnesium (Mg), and tungsten (Te) may be added. Let's say.

[0014] The active metal brazing material as described above can be used in a method for manufacturing a bonded body. The method for manufacturing the bonded body is to convert the active metal brazing material according to the embodiment into an active metal brazing material paste. The process involves applying an active metal brazing paste onto a ceramic substrate to form an active metal brazing layer. a step of forming a brazing material layer on the substrate, a step of placing a metal plate on the brazing material layer, and a step of bonding the brazing material by heating. The present invention is characterized by the following features. An example of a laminated body according to the embodiment is shown in Fig. 1. Also, a bonded body according to the embodiment is shown in Fig. 2. An example of a bonding method is shown in FIG. 3. In the figure, the reference numerals 1 is a laminate, 2 is a ceramic substrate, 3 is an active metal brazing material layer, and 4 is a metal plate. Symbol 5 is the belt conveyor, symbol 6 is the temperature rising zone, symbol 7 is the heat bonding zone, symbol 8 is the temperature dropping zone The reference numeral 9 denotes an active metal bonding layer, and the reference numeral 10 denotes a bonded body. The laminate 1 is a laminate of a ceramic substrate 2, an active metal brazing material layer 3, and a metal plate 4. The laminate 1 is heated and bonded to form a bonded body 10. Therefore, before bonding, the laminate 1 is The bonded body 10 shows the product after bonding.

[0015] First, a step of converting the active metal brazing material according to the embodiment into an active metal brazing material paste is carried out. The metal brazing material is mixed with binder, plasticizer, solvent, etc. It is preferable to use a kneader. The kneader may be a two-roll type, a three-roll type, a kneader type, or the like. Examples include:

[0016] Next, an active metal brazing paste is applied to the ceramic substrate to form an active metal brazing layer. The process of forming the active metal brazing material layer may be performed by screen printing or the like. The active metal brazing material layer is provided at the location where the metal plate is to be placed. The thickness of the filler layer is preferably in the range of 10 μm to 60 μm. When metal plates 4 are to be bonded to both sides of the substrate 2, active brazing metal layers 2 are provided on both sides.

[0017] Ceramic substrates include nitride ceramic substrates and oxide ceramic substrates. Examples of nitride ceramic substrates include silicon nitride substrates and aluminum nitride substrates. In addition, oxide ceramic substrates include aluminum oxide substrates, zirconium oxide substrates, and Examples include silicon substrates. Among ceramic substrates, silicon nitride substrates are preferred. There are also nitrided alloys with thermal conductivity of 40W / m·K or more, and even 80W / m·K or more. Silicon substrates have three-point bending strengths of 600 MPa or more, and even 700 MPa or more. In addition, aluminum nitride substrates have a thermal conductivity of 160 W / m·K or more, and even 200 W / The aluminum nitride substrate has a three-point bending strength of 300 to 450 It is about MPa. In addition, the three-point bending strength of the aluminum oxide substrate is about 300 to 450 MPa. In addition, the thermal conductivity of the aluminum oxide substrate is approximately 20 to 30 W / m·K. In addition, the zirconium oxide substrate has a high three-point bending strength of about 550 MPa, but its thermal conductivity is 30 The value is about 50W / m·K. A mixture of aluminum oxide and zirconium oxide is also For example, if the aluminum oxide content is high, Included in the aluminum oxide substrate. The thickness of the ceramic substrate 1 is preferably within the range of 0.2 mm to 3 mm. If the thickness is less than 0.2 mm, the insulation may be insufficient. Although it has good insulation properties, it has poor heat dissipation properties. In addition, because silicon nitride substrates are strong, the substrate thickness can be set to 0.2 mm or more and 0.8 mm or less. The thickness can be set within the range of 0.2 mm to 0.4 mm. Next, a step of placing a metal plate on the active brazing metal layer is performed. The metal plate is a copper plate (including a copper alloy plate). The copper plate is preferably oxygen-free copper. It is preferable that the thickness is 0.3 mm or more, and more preferably 0.8 mm or more. Although one metal plate is disposed, a plurality of metal plates may be disposed.

[0018] Next, a heat bonding process is carried out. The bonding temperature should be between 650°C and 950°C. In addition, the heat bonding step is preferably carried out using a continuous furnace, a vacuum furnace, a hot press, or the like. can be done. A continuous furnace is a method in which the laminate (objects to be joined) is heated while being transported using a belt conveyor or the like. It is excellent for mass production because it can be heated and bonded while being transported. The layer is placed and heated. The vacuum level is 10 -2 Pa or less is preferable. Since it uses a sealed space, it is not affected by the atmosphere. On the other hand, vacuum furnaces use an enclosed space, making them suitable for mass production. Hot pressing is a method of bonding laminates by heating them while applying pressure. Since pressure is used, warping of the resulting bonded body can be suppressed. Since the processing is done under pressure, there is a limit to how much can be processed at once. It cannot be said that productivity is good.

[0019] It is preferable to use a continuous furnace for the heat bonding process. As shown in Figure 2, the continuous furnace is The stack 1 is placed on a conveyor 5 and conveyed. The continuous furnace has a temperature rising zone 6, a heat bonding zone 7, and a temperature dropping zone 8. The temperature rising zone 6 is an area where the temperature is raised from room temperature to the thermal bonding temperature. The bonding zone 7 is an area where the temperature is maintained at the bonding temperature. The heating zone 6, the heat bonding zone 7 and the cooling zone 8 are the areas where the temperature is lowered from the room temperature to the room temperature. The length of each zone can be set to any length required for joining. For example, the temperature rising zone 6 may be divided into two or more zones. Temperature control can also be performed.

[0020] The heat bonding process using a continuous furnace is preferably carried out in a nitrogen atmosphere. It is not an airtight space like a vacuum furnace, so a nitrogen atmosphere is used to prevent it from being affected by the atmosphere. It is preferable to place it in the air. In a continuous furnace, the objects to be bonded are transported through multiple zones while being bonded. Therefore, there may be a difference between the temperature set in the furnace and the temperature of the bonded object. Nitrogen flow may be used to control the temperature. In some furnaces, the temperature may vary by ±50°C from the set temperature. The active metal brazing material according to the embodiment contains CuSn alloy particles or CuIn alloy particles. This allows stable bonding even if temperature variations occur inside the furnace. Therefore, a method for manufacturing a bonded body that is excellent in mass productivity can be provided. By carrying out the heat bonding step, a bonded body can be obtained. 3 is the active metal bonding layer 9.

[0021] The resulting bonded body 10 is then subjected to etching or other processing to give the metal plate 4 a circuit shape. By giving a circuit shape to the metal plate 4, it becomes a ceramic circuit board.

[0022] (Example) (Examples 1 to 5, Comparative Example 1) The active metal brazing materials prepared were those shown in Table 1. In Examples 1 to 5, CuSn alloy particles or In Comparative Example 1, Cu powder and Sn powder were used separately. Each of these was used.

[0023] [Table 1]

[0024] Next, a binder, a plasticizer, a solvent, etc. were added to the active metal brazing material, and a mixing process was carried out. In the mixing step, a kneader was used to prepare an active metal brazing paste. An active metal brazing paste was applied to the ceramic substrate to form an active metal brazing layer. The thickness of the active metal brazing material layer was set to be in the range of 10 μm to 60 μm. A copper plate was placed on the layer. An active metal brazing material layer and a copper plate were placed on both sides of the ceramic substrate. The laminate combinations are shown in Table 2.

[0025] [Table 2]

[0026] Next, a bonding process was carried out using a continuous furnace. One lot consisted of 100 laminates. Five lots were bonded, and the yield and bonding strength of the resulting bonded bodies were measured. The values, minimum and maximum values ​​were investigated, and the results are shown in Table 3.

[0027] [Table 3]

[0028] First, the temperature of the laminated body fed into the heating and bonding zone of the continuous furnace varies by about ±50°C. The average yield and bonding strength of the bonded bodies of the Example and Comparative Example were the same. On the other hand, in the example, the minimum to maximum value of the bonding strength was ±3 kN / m , and even within the range of ±2 kN / m. On the other hand, in the comparative example, the bonding strength is stable. The comparative example was affected by temperature variations.

[0029] Although several embodiments of the present invention have been illustrated above, these embodiments are presented as examples. These novel embodiments are not intended to limit the scope of the invention. It is possible to implement the invention in various other forms, and various modifications are possible without departing from the spirit of the invention. Various omissions, substitutions, and modifications may be made. The scope of the invention and its equivalents as defined in the claims are included in the scope and spirit of the invention. In addition, the above-described embodiments can be implemented in combination with each other. [Explanation of symbols]

[0030] 1...Laminate 2...Ceramic substrate 3...Active metal brazing material layer 4...Metal plate 5...Conveyor belt 6...Heating zone 7...Heated bonding zone 8...Temperature drop zone 9…Active metal bonding layer 10...Zygote

Claims

1. Ti component particles and one or two of CuSn alloy particles or CuIn alloy particles An active metal brazing material comprising: The Ti component particles are at least one of Ti particles and Ti hydride particles, The CuSn alloy particles are composed of Cu and Sn, and when the total of Cu and Sn is 100 parts by mass, Cu is in the range of 30 parts by mass or more and 80 parts by mass or less, and Sn is in the range of 20 parts by mass or more and 70 parts by mass or less can be, The CuIn alloy particles are composed of Cu and In, and when the total of Cu and In is 100 parts by mass, Cu is in the range of 30 parts by mass or more and 80 parts by mass or less, and In is in the range of 20 parts by mass or more and 70 parts by mass or less An active metal brazing material characterized by:

2. The average particle size of the Ti component particles and the CuSn alloy particles is 20 μm≧average particle size of CuSn alloy particles>average particle size of Ti component particles, 2. The active metal brazing material according to claim 1, wherein the following is satisfied:

3. The CuSn alloy particles have an average particle size in the range of 2 μm to 20 μm. The active metal brazing material according to claim 1 or 2,

4. When the total amount of Ti component particles and CuSn alloy particles is 100 mass %, the Ti component particles are 1% by mass or more and 15% by mass or less, and CuSn alloy particles in the range of 85% by mass or more and 99% by mass or less 3. The active metal brazing material according to claim 1, wherein the active metal brazing material is selected from the group consisting of fluorine, fluorine, iodine, hydroxyl, methyl methacrylate ...

5. When the total amount of Ti component particles and CuSn alloy particles is 100 mass %, the Ti component particles are 1% by mass or more and 15% by mass or less, and CuSn alloy particles in the range of 85% by mass or more and 99% by mass or less 4. The active metal brazing material according to claim 3, wherein the active metal brazing material is selected from the group consisting of fluorine, fluorine, iodine, hydroxyl, methyl methacrylate ...

6. 10. The method according to claim 1, wherein the carbon particles are contained in an amount of 0.1% by mass or more and 2% by mass or less. Item 3. The active metal brazing material according to item 2.

7. 5. The active material according to claim 4, wherein the active material contains carbon particles in an amount of 0.1% by mass or more and 2% by mass or less. High-resistance metal brazing filler metal.

8. 6. The active material according to claim 5, wherein the active material contains carbon particles in an amount of 0.1% by mass or more and 2% by mass or less. High-resistance metal brazing filler metal.

9. a step of preparing an active metal brazing material paste from the active metal brazing material according to claim 1 or 2; An active metal brazing material layer is formed by applying an active metal brazing material paste onto a ceramic substrate. a step of placing a metal plate on the active brazing material layer, and a step of heat-bonding the metal plate. A method for producing a bonded body, comprising:

10. A step of preparing an active metal brazing material paste from the active metal brazing material according to claim 5; A step of applying an active metal brazing paste onto a substrate to form an active metal brazing layer; The method is characterized by comprising the steps of placing a metal plate on the metal brazing material layer and heat-bonding the metal plate. A method for manufacturing a bonded body.

11. 9. The method for manufacturing a bonded body according to claim 8, wherein a continuous furnace is used in the heat bonding step. 。

12. 10. The method for manufacturing a bonded body according to claim 9, wherein a continuous furnace is used in the heat bonding step. 。

13. 11. The method according to claim 10, wherein the ceramic substrate is a silicon nitride substrate and the metal plate is a copper plate. A method for manufacturing a bonded body.

14. 12. The method according to claim 11, wherein the ceramic substrate is a silicon nitride substrate and the metal plate is a copper plate. A method for manufacturing a bonded body.

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