A method for soldering ceramic and metal using an activated metal solder paste composition.

Abstract

The active metal solder paste composition includes an adhesive and a metal powder, the metal powder includes an active metal solder powder and a soldering auxiliary metal powder, the soldering auxiliary metal powder includes copper powder and / or a copper-silver alloy powder, and the active metal solder powder is an alloy powder of copper, silver and an active metal, and based on the total weight of the metal powder, the active metal content is 1.5 wt% or more, the silver content is 40 to 90 wt%, and the oxygen content is 0.5 wt% or less. The composition can stabilize the soldering quality and reduce the cost of materials. The present invention also relates to a solder paste and a method for soldering ceramics and metals.

Description

Technical Field

[0001] (Priority Information) This disclosure claims the priority of Chinese Patent Publication No. 202111155220.8, titled "Active Metal Solder Paste Composition, Solder Paste, and Method for Soldering Ceramic and Metal", filed with the China National Intellectual Property Administration on September 29, 2021, and all of its contents are incorporated herein by reference.

[0002] This application relates to the technical field of soldering, specifically to an active metal solder paste composition, a solder paste, and a method for soldering ceramic and metal.

Background Art

[0003] Currently, active metal brazing is a common method for soldering ceramics to ceramics, metals to ceramics, especially non-oxide ceramics such as silicon nitride and aluminum nitride. For active metal brazing, solders containing active metals such as Ti and Zr are used. These active metals can react with ceramics at high temperatures, improve the wettability of the solder, and form chemical bonds with ceramics. Adding an adhesive to the powdered solder and screen-printing it on the soldering interface is a common soldering method. The adhesive is composed of different types of organic substances. Before reaching the soldering temperature, most of the adhesive evaporates and separates from the soldering interface, but a small amount of organic substances decompose, causing carbon to remain on the soldering interface, which affects the soldering quality and subsequent processes. In existing ternary alloy active metal solders, the content of the active metal is small, and it is difficult to accurately control the content of the active metal in the ternary alloy product during manufacturing, resulting in large fluctuations in the content of the active metal. Since the content of the active metal has a great impact on soldering, such fluctuations cause instability in the subsequent soldering quality. Also, due to the high silver content in existing active metal solders, the cost of the solder is high.

Summary of the Invention

[0004] The purpose of this disclosure is to address the challenges of carbon remaining at the soldering interface, affecting soldering quality and subsequent processes, and the difficulty and cost associated with precisely controlling the active metal content in the solder. [Means for solving the problem]

[0005] To achieve the above objective, the activated metal solder paste composition according to the first aspect of this disclosure comprises an adhesive and a metal powder, wherein the metal powder comprises activated metal solder powder and a soldering auxiliary metal powder, the soldering auxiliary metal powder comprises copper powder and / or copper-silver alloy powder, the activated metal solder powder is an alloy powder containing copper, silver and an activated metal, and the activated metal content is 1.5% by weight or more, the silver content is 40-90% by weight, and the oxygen content is 0.5% by weight or less, based on the total weight of the metal powder.

[0006] In some embodiments of the present disclosure, the oxygen content of the soldering auxiliary metal powder is 2% by weight or less, the carbon content of the soldering auxiliary metal powder is 0.75% by weight or less, and the molar ratio of oxygen to carbon in the soldering auxiliary metal powder is 2 or more, based on the total weight of the soldering auxiliary metal powder.

[0007] In some embodiments of the present disclosure, the soldering auxiliary metal powder has an oxygen content of 0.3 to 0.5% by weight and a carbon content of 0.1% by weight or less, based on the total weight of the soldering auxiliary metal powder.

[0008] In some embodiments of this disclosure, the content of the soldering auxiliary metal powder is 10 to 50% by weight and the content of the activated metal solder powder is 50 to 90% by weight, based on the total weight of the metal powder.

[0009] In some embodiments of this disclosure, the active metal content is 1.8 to 4.5% by weight, the silver content is 42 to 85% by weight, and the oxygen content is 0.001 to 0.3% by weight, based on the total weight of the metal powder.

[0010] In some embodiments of this disclosure, the active metal content is 2-4% by weight, the silver content is 45-80% by weight, and the oxygen content is 0.06-0.2% by weight, based on the total weight of the metal powder.

[0011] In some embodiments of this disclosure, the active metal is one or more selected from Ti, Zr, and Hf.

[0012] In some embodiments of this disclosure, the active metal is Ti.

[0013] In some embodiments of this disclosure, the active metal content is 1.5 to 10% by weight, based on the total weight of the active metal solder powder.

[0014] In some embodiments of this disclosure, the active metal content is 2 to 6% by weight, based on the total weight of the active metal solder powder.

[0015] In some embodiments of this disclosure, the weight ratio of Ag to Cu in the activated metal solder powder is 3:7 to 9:1.

[0016] In some embodiments of this disclosure, the weight ratio of Ag to Cu in the activated metal solder powder is 6:4 to 8:2.

[0017] In some embodiments of this disclosure, the oxygen content of the activated metal solder powder is 0.5% by weight or less.

[0018] In some embodiments of this disclosure, the particle size of the active metal solder powder is 50 μm or less, and the particle size of the soldering auxiliary metal powder is 50 μm or less.

[0019] In some embodiments of the present disclosure, based on the total weight of the composition, the content of the metal powder is 80 to 95% by weight, and the content of the adhesive is 5 to 20% by weight.

[0020] In some embodiments of the present disclosure, based on the total weight of the composition, the content of the metal powder is 85 to 90% by weight, and the content of the adhesive is 10 to 15% by weight.

[0021] The solder paste according to the second aspect of the present disclosure is manufactured using the active metal solder paste composition described in the first aspect of the present disclosure.

[0022] A method for soldering a ceramic and a metal using the active metal solder paste composition according to the first aspect of the present disclosure or the solder paste according to the second aspect of the present disclosure according to the third aspect of the present disclosure is to connect the solder target ceramic and the solder target metal with the composition or the solder paste to form a connection member of the solder target, and send the connection member of the solder target into a vacuum brazing furnace for heating and soldering. The ratio of the organic matter content of the connection member to be soldered to the effective volume of the vacuum brazing furnace is 0.4 g / m , ,

[0024] is as follows.

[0023] In some embodiments of the present disclosure, the method further includes printing the composition or the solder paste on the surface of the solder target ceramic and baking at 60 to 100 °C for 20 to 60 minutes, fixedly connecting the solder target metal and the baked solder paste to obtain the connection member to be soldered, and sending the connection member to be soldered into a vacuum brazing furnace for heating and soldering. The ratio of the organic matter content of the connection member to be soldered to the effective volume of the vacuum brazing furnace is 0.3 g / m 3 is as follows.

Advantages of the Invention

[0024] According to the above technical means, the active metal solder paste composition of the present disclosure contains copper powder and / or copper-silver alloy powder, and has an oxide layer on the surface of the copper powder and / or copper-silver alloy powder. Therefore, copper is likely to oxidize and decompose at the soldering temperature to generate oxygen gas, and by consuming the carbon remaining after the decomposition of the organic matter in the adhesive, the solder activity can be improved. The active metal solder paste composition of the present disclosure further contains copper powder or copper-silver alloy powder in addition to the active metal solder powder, avoiding the defect that it is difficult to directly control the content of the active metal in the alloy powder. By adjusting the amount of copper powder or copper-silver alloy powder in the composition, the content of the active metal in the solder paste can be controlled. Furthermore, the soldering quality can be stabilized and the influence on subsequent processes can be reduced. Also, the copper powder and copper-silver alloy powder have a low cost, and adding them to the solder paste composition can reduce the material cost.

[0025] Regarding the advantages of the embodiments of the present disclosure, some are described in the following specification, some will become clear based on the specification or will be understood by implementing the embodiments of the present disclosure.

Brief Description of the Drawings

[0026] The drawings provide a further understanding of the present disclosure and form part of the specification, and together with the following specific embodiments, explain the present disclosure, but do not limit the present disclosure.

[0027] [Figure 1] It is an ultrasonic test diagram of the soldering location of the soldering member in Example 1. [Figure 2] It is an ultrasonic test diagram of the soldering location of the soldering member in Comparative Example 1. [Figure 3] It is an ultrasonic test diagram of the soldering location of the soldering member in Comparative Example 2. [Figure 4] It is an ultrasonic test diagram of the soldering location of the soldering member in Comparative Example 4.

Modes for Carrying Out the Invention

[0028] The following describes specific embodiments of this disclosure in detail. It should be understood that the specific embodiments described herein are for illustrative purposes only and do not limit this disclosure.

[0029] An activated metal solder paste composition according to a first aspect of this disclosure comprises an adhesive and a metal powder, wherein the metal powder comprises activated metal solder powder and a soldering auxiliary metal powder, the soldering auxiliary metal powder comprises copper powder and / or copper-silver alloy powder, the activated metal solder powder is an alloy powder of Cu, Ag and an activated metal, and the activated metal content is 1.5% by weight or more, the silver content is 40-90% by weight, and the oxygen content is 0.5% by weight or less, based on the total weight of the metal powder.

[0030] According to the above technical means, the copper contained in the activated metal solder paste composition of this disclosure can decompose at the soldering temperature to generate oxygen gas, which helps to consume the carbon remaining after the decomposition of the adhesive and avoids the carbon remaining at the soldering interface affecting the soldering quality. Furthermore, existing ternary alloy activated metal solder materials have a low active metal content, and it is difficult to accurately control the active metal content in the ternary alloy product using general manufacturing methods. The solder paste composition of this disclosure reduces the control requirements for the active metal content in the ternary alloy and lowers the difficulty of manufacturing the ternary alloy by adjusting and controlling the active metal solder content in the total amount of the composition by introducing copper powder or silver-copper alloy powder. Using the activated metal solder paste composition of this disclosure, soldering quality can be stabilized and the impact on subsequent soldering processes can be reduced. In addition, copper powder and silver-copper alloy powder are low-cost, and adding them to the solder paste can reduce the cost of materials.

[0031] In one embodiment of the present disclosure, the oxygen content of the metal powder is 0.48% by weight or less, or 0.46% by weight or less, or 0.01 to 0.5% by weight, and in another embodiment of the present disclosure, the oxygen content of the metal powder is 0.01 to 0.48% by weight, or 0.01 to 0.46% by weight, or 0.1 to 0.5% by weight, or 0.1 to 0.48% by weight, or 0.1 to 0.46% by weight.

[0032] In one embodiment, in order to promote the reactivity of copper during the soldering process and improve soldering quality, the oxygen content of the soldering auxiliary metal powder is 2% by weight or less, for example, 0.3 to 0.5% by weight, based on the total weight of the soldering auxiliary metal powder. Furthermore, in order to avoid introducing excessive oxygen into the solder paste and affecting the soldering performance of the active metal, the carbon content of the soldering auxiliary metal powder is 0.75% by weight or less, for example, 0.6% by weight or less or 0.5% by weight or less; in another embodiment of the present disclosure, the carbon content of the soldering auxiliary metal powder is 0.01 to 0.75% by weight, or 0.02 to 0.6% by weight, or 0.05 to 0.5% by weight; in yet another embodiment of the present disclosure, the carbon content of the soldering auxiliary metal powder is 0.3% by weight or less, or 0.25% by weight or less, or 0.1% by weight or less, or 0.01 to 0.3% by weight, or 0.01 to 0.25% by weight, or 0.01 to 0.1% by weight; and the molar ratio of oxygen to carbon in the soldering auxiliary metal powder is 2 or more, for example, 2 to 8, or 2 to 6, or 2.2 to 5.6.

[0033] In this embodiment, the oxygen and carbon content of the soldering auxiliary metal powder are appropriate and can be used to further improve soldering quality by avoiding any impact on the soldering performance of the solder paste.

[0034] In one embodiment, in order to further improve the soldering performance of the solder paste composition, the active metal content is 1.8 to 4.5% by weight, the silver content is 42 to 85% by weight, and the oxygen content is 0.001 to 0.3% by weight, based on the total weight of the metal powder. In another embodiment of the present disclosure, the active metal content is 2 to 4% by weight, the silver content is 45 to 80% by weight, and the oxygen content is 0.06 to 0.2% by weight, based on the total weight of the metal powder.

[0035] In the solder paste composition of this disclosure, the weight ratio of soldering auxiliary metal powder to activated metal solder powder is not particularly limited, and it is sufficient that the content of activated metal, silver, and oxygen in the solder paste composition satisfies the above content ranges. For example, based on the total weight of the metal powder, the content of the soldering auxiliary metal powder may be 10 to 50% by weight, and the content of activated metal solder powder may be 50 to 90% by weight. In another embodiment of this disclosure, based on the total weight of the metal powder, the content of the soldering auxiliary metal powder may be 15 to 40% by weight, and the content of activated metal solder powder may be 60 to 85% by weight.

[0036] In the above embodiment, the content of activated metal titanium in the solder paste composition is maintained within a suitable range, and the stability of the soldering quality of the activated metal solder paste composition can be further improved.

[0037] In one embodiment, the active metal is one or more selected from Ti, Zr, and Hf. In some embodiments of this disclosure, the active metal is Ti, i.e., the active metal solder powder is copper-silver-titanium solder powder, and the active metal content is 1.5 to 10% by weight based on the total weight of the active metal solder powder. In another embodiment of this disclosure, the active metal content is 2 to 6% by weight based on the total weight of the active metal solder powder. The weight ratio of Ag to Cu in the active metal solder powder is 3:7 to 9:1, and in another embodiment of this disclosure, the weight ratio of Ag to Cu in the active metal solder powder is 6:4 to 8:2. In these embodiments, the soldering performance of the active metal solder powder can be further improved, and the soldering quality can be further enhanced.

[0038] In one embodiment, the oxygen content of the activated metal solder powder is 0.5% by weight or less, for example, 0.01 to 0.5% by weight, or 0.01 to 0.45% by weight, or 0.02 to 0.4% by weight.

[0039] In one embodiment, the particle size of the activated metal solder powder is 50 μm or less, and the particle size of the soldering auxiliary metal powder is 50 μm or less. In this embodiment, the particle size of the activated metal powder has a high degree of compatibility with the mesh count of the selected printing screen, which can further improve soldering quality.

[0040] In one embodiment, the content of the metal powder is 80-95% by weight and the content of the adhesive is 5-20% by weight, based on the total weight of the solder paste composition. In another embodiment of the present disclosure, the content of the metal powder is 85-90% by weight and the content of the adhesive is 10-15% by weight, based on the total weight of the solder paste composition. The adhesive may be any solder paste adhesive common in the art and is not particularly limited in this disclosure.

[0041] The solder paste according to a second aspect of this disclosure is manufactured using the activated metal solder paste composition described in a first aspect of this disclosure.

[0042] A third aspect of this disclosure, a method for soldering a ceramic and a metal using the activated metal solder paste composition described in the first aspect of this disclosure or the solder paste described in the second aspect of this disclosure, includes the steps of connecting the ceramic and the metal to be soldered with the composition or the solder paste to form a connecting member to be soldered, and feeding the connecting member to be soldered into a vacuum brazing furnace and heating it to solder, wherein the ratio of the organic content of the connecting member to be soldered to the effective volume of the vacuum brazing furnace is 0.4 g / m². 3 The following applies:

[0043] In one embodiment, the method further includes the steps of printing the above composition or solder paste onto the surface of a ceramic to be soldered and baking it at 60-100°C for 20-60 minutes, and in another embodiment, baking it at 70-80°C for 30 minutes; fixing the metal to be soldered and the baked solder paste together to obtain a connecting member to be soldered; and feeding the connecting member to be soldered into a vacuum brazing furnace and heating it to solder it. In order to rapidly discharge organic matter and further improve the soldering performance of the solder paste, the ratio of the organic matter content of the connecting member to be soldered to the effective volume of the vacuum brazing furnace is 0.3 g / m². 3 In another embodiment, the ratio of the organic content of the connecting member to be soldered to the effective volume of the vacuum brazing furnace is 0.2 g / m 3 The following applies:

[0044] In one embodiment, before the soldering process, the copper powder in the soldering auxiliary metal powder is subjected to a thermal oxidation treatment to prevent the passivation layer of the copper powder from affecting the soldering quality. The method of the thermal oxidation treatment involves heating the copper powder in air or oxygen gas to oxidize it.

[0045] In one embodiment, the soldering process is divided into five stages according to different temperature points, the temperature points being based on the melting point of the active metal powder in the solder paste. The five stages include the following 1 to 5.

[0046] 1. A heating step from room temperature of 25°C to a temperature 10 to 100°C lower than the melting point of the activated metal powder, for example, a heating step from room temperature of 25°C to a temperature 35 to 65°C lower than the melting point of the activated metal powder.

[0047] 2. Holding the temperature at the melting point of the activated metal powder.

[0048] 3. A heating step from the melting point of the activated metal powder to the soldering temperature, wherein the soldering temperature is not 50°C lower than the equivalent melting point and is not 20°C higher than the melting point of the component to be soldered.

[0049] 4. Holding the temperature at the soldering temperature.

[0050] 5. The subsequent cooling phase.

[0051] In one embodiment, the soldering process described above is as follows:

[0052] After placing the material in the furnace, a vacuum is created, and when the vacuum level drops below 0.1 Pa, heating begins, entering the first stage. In the first stage, the heating rate should be less than 10°C / min before exceeding 200°C. After exceeding 200°C, the heating may be increased at a constant rate, at different rates, or maintained at a certain temperature, ensuring that the average heating rate is less than 5°C / min and the fastest rate is less than 10°C / min. The method of adjusting the heating rate, heating, and maintenance ensures that the maximum pressure is 0.1 Pa or less and that the temperature at the maximum pressure is less than or equal to the maximum temperature of the first stage. The maintenance time in the second stage is 10 to 40 minutes. In the third stage, the average heating rate is less than 5°C / min, and the heating time does not exceed 90 minutes. The maintenance time in the fourth stage is 30 to 120 minutes. In the fifth stage, the cooling rate down to 600°C is less than 5°C / min, and once 600°C is reached, natural cooling is allowed without temperature control.

[0053] The present disclosure will be further described below with reference to examples. All raw materials used in the examples are commercially available. [Examples]

[0054] The weight composition of the activated metal solder powder is 70% by weight of Ag, 4% by weight of Ti, with a particle size of 50 μm or less, an oxygen content of 0.08% by weight, and the remainder being copper.

[0055] The soldering aid metal powder is copper powder with a particle size of 50 μm or less, an oxygen content of 0.2% by weight, and a carbon content of 0.05% by weight. The copper powder is then subjected to thermal oxidation treatment to increase the oxygen content to 0.45% by weight.

[0056] The metal powder consists of 80% by weight of activated metal solder powder and 20% by weight of soldering aid metal powder, and an adhesive is added to prepare a solder paste. Based on the total weight of the solder paste composition, the adhesive content is 15% by weight. When the adhesive evaporates on its own, the residue when heated to 400°C is 2.3% by weight. The components of the adhesive used are 71.5% by weight of terpineol, 8% by weight of stearic acid, 8% by weight of polyethylene glycol 600, 4% by weight of polyethylene glycol 2000, 2.5% by weight of EC-90-110, 5% by weight of oxalic acid, and 1% by weight of polyurethane wax 6650.

[0057] Solder paste is printed onto silicon nitride ceramic and dried at 90°C for 30 minutes, with the remaining organic matter accounting for 0.9% by weight of the remaining solder paste mass. A copper sheet is placed on the solder paste, assembled, and then heated and soldered in a vacuum brazing furnace. The ratio of the remaining organic matter content in the soldering components placed in the furnace to the effective volume of the brazing furnace is 0.1 g / m². 3 That is the case.

[0058] The soldering process is as follows: After placing the component in the furnace, a vacuum is created, and when the vacuum level drops below 0.1 Pa, heating begins, entering the first stage. In the first stage, the heating rate is set to 5°C / min before exceeding 200°C. After exceeding 200°C, the temperature is raised to 740°C at a constant rate of 3°C / min. The maximum pressure is 0.06 Pa, and the temperature at the maximum pressure is 465°C. In the second stage, the component is held at 740°C for 25 minutes. In the third stage, the temperature is raised to 890°C at a rate of 3°C / min. In the fourth stage, the component is held at 890°C for 45 minutes. In the fifth stage, the temperature is lowered to 600°C at a rate of 2°C / min, and once it reaches 600°C, natural cooling is allowed without temperature control. Figure 1 shows the ultrasonic test results of the soldering area of ​​the component. [Examples]

[0059] The soldering process is the same as in Example 1, except that the weight composition of the activated metal solder powder is 70% by weight Ag, 3% by weight Ti, 0.08% by weight oxygen content, and the remainder Cu. [Examples]

[0060] The soldering process is the same as in Example 1, except that the soldering auxiliary metal powder is a silver-copper alloy powder with a particle size of 50 μm or less, a silver content of 50 wt%, an oxygen content of 0.2 wt%, a carbon content of 0.05 wt%, and the remainder being Cu, and the silver-copper powder is subjected to thermal oxidation treatment to increase the oxygen content to 0.45 wt%. [Examples]

[0061] The soldering process is the same as in Example 1, except that the weight composition of the activated metal solder powder is 70% by weight Ag, 4% by weight Ti, 0.4% by weight oxygen content, and the remainder Cu. [Examples]

[0062] The soldering process is the same as in Example 1, except that the weight composition of the activated metal solder powder is 70% by weight Ag, 4% by weight Zr, particle size of 50 μm or less, oxygen content of 0.08% by weight, and the remainder being Cu. (Comparative Example 1)

[0063] The soldering process is the same as in Example 1, except that the metal powder consists only of active metal solder powder and does not contain soldering auxiliary metal powder, and an adhesive is added to prepare the solder paste. Figure 2 shows the ultrasonic test results of the soldered area of ​​the soldered component. (Comparative Example 2)

[0064] The soldering process involves an active metal solder powder with a weight composition of 70% by weight Ag, 4% by weight Ti, a particle size of 50 μm or less, an oxygen content of 0.8% by weight, and the remainder being Cu. The soldering aid metal powder is the same as in Example 1, except that it is copper powder with a particle size of 50 μm or less, an oxygen content of 3% by weight, and a carbon content of 1% by weight. Figure 3 shows the ultrasonic test diagram of the soldered area of ​​the soldered member. (Comparative Example 3)

[0065] The soldering process involves an active metal solder powder with a weight composition of 70% by weight Ag, 2% by weight Ti, a particle size of 50 μm or less, an oxygen content of 0.8% by weight, and the remainder being Cu. This is the same as Example 1, except that the metal powder consists of 30% by weight of activated metal solder powder and 70% by weight of soldering aid metal powder. (Comparative Example 4)

[0066] The soldering process is the same as in Example 1, except that the metal powder consists of 30% by weight of activated metal solder powder and 70% by weight of soldering auxiliary metal powder, and an adhesive is added to prepare the solder paste. Figure 4 shows the ultrasonic test results of the soldered area of ​​the soldered member. (Comparative Example 5)

[0067] The soldering process is performed when the ratio of the remaining organic matter content in the soldering material placed in the furnace to the effective volume of the brazing furnace is 0.8 g / m³. 3 Except for the fact that it is the same as Example 1, this is the same as Example 1. [Example Test]

[0068] The peel strength testing device is a universal testing machine, the testing software is QCTech-A3, the peel speed is 50 mm / min, and the peel stroke is greater than 25 mm. [Table 1]

[0069] Based on the data analysis in Table 1, a comparison of the data from Examples 1-5 and Comparative Examples 1-5 shows that the solder paste manufactured in this disclosure can reduce the amount of ternary alloy solder powder used and thus reduce the material cost of the solder paste by adding copper powder to its metal powder. Furthermore, the solder paste of this disclosure can exhibit soldering quality and peel strength equivalent to or better than existing solder pastes containing only ternary alloy solder powder. A comparison of the data from Example 1 and Example 4 shows that when the oxygen content in the metal powder of this disclosure is 0.06-0.2% by weight, the solder paste can exhibit better soldering performance. A comparison of the data from Example 1 and Comparative Example 5 shows that when the ratio of the organic matter content of the connecting member to be soldered to the effective volume of the vacuum brazing furnace is 0.4 g / m² 3 The following conditions indicate that the soldering performance of solder paste can be further improved.

[0070] The above embodiments are merely examples of some embodiments of the present disclosure, and although their descriptions are specific and detailed, they should not be understood as limiting the scope of the patent of this disclosure. Furthermore, those skilled in the art can make several modifications and improvements without departing from the concept of this disclosure, and all of these fall within the scope of protection of this disclosure. Therefore, the scope of protection of the patent of this disclosure should be based on the attached claims.

Claims

1. A method for soldering ceramic and metal using an activated metal solder paste composition, The activated metal solder paste composition comprises an adhesive and metal powder. The metal powder comprises activated metal solder powder and soldering auxiliary metal powder, wherein the content of the soldering auxiliary metal powder is 10 to 50% by weight, and the content of the activated metal solder powder is 50 to 90% by weight, based on the total weight of the metal powder, the soldering auxiliary metal powder comprises copper powder and / or copper-silver alloy powder, and the activated metal solder powder is an alloy powder containing copper, silver, and activated metal. Based on the total weight of the metal powder, the active metal content is 1.8 to 4.5% by weight, the silver content is 42 to 85% by weight, the oxygen content is 0.001 to 0.3% by weight, and the remainder of the metal powder is copper, or copper and carbon. When the metal powder contains carbon, the carbon content of the soldering auxiliary metal powder is 0.75% by weight or less, based on the total weight of the soldering auxiliary metal powder. The soldering method is, The ceramic to be soldered and the metal to be soldered are connected by the activated metal solder paste composition to form a connecting member to be soldered. The process includes the step of feeding the connecting member to be soldered into a vacuum brazing furnace, heating it, and soldering it. The ratio of the organic content of the connecting member to be soldered to the effective volume of the vacuum brazing furnace is 0.4 g / m ３ The soldering method is as follows:

2. The soldering method according to claim 1, wherein, based on the total weight of the soldering auxiliary metal powder, the oxygen content of the soldering auxiliary metal powder is 2% by weight or less, and the molar ratio of oxygen to carbon in the soldering auxiliary metal powder is 2 or more.

3. The soldering method according to claim 1, wherein, based on the total weight of the soldering auxiliary metal powder, the oxygen content of the soldering auxiliary metal powder is 0.3 to 0.5% by weight and the carbon content is 0.1% by weight or less.

4. The soldering method according to claim 1, wherein, based on the total weight of the metal powder, the active metal content is 2 to 4% by weight, the silver content is 45 to 80% by weight, and the oxygen content is 0.06 to 0.2% by weight.

5. The soldering method according to claim 1, wherein the active metal is one or more selected from Ti, Zr, and Hf.

6. The soldering method according to claim 1, wherein the active metal is Ti.

7. The soldering method according to claim 1, wherein the content of the active metal is 1.5 to 10% by weight, based on the total weight of the active metal solder powder.

8. The soldering method according to claim 1, wherein the content of the active metal is 2 to 6% by weight, based on the total weight of the active metal solder powder.

9. The soldering method according to claim 1, wherein the weight ratio of Ag to Cu in the activated metal solder powder is 3:7 to 9:

1.

10. The soldering method according to claim 1, wherein the weight ratio of Ag to Cu in the activated metal solder powder is 6:4 to 8:

2.

11. The soldering method according to claim 1, wherein the oxygen content of the activated metal solder powder is 0.5% by weight or less.

12. The soldering method according to claim 1, wherein the particle size of the activated metal solder powder is 50 μm or less, and the particle size of the soldering auxiliary metal powder is 50 μm or less.

13. The soldering method according to claim 1, wherein, based on the total weight of the activated metal solder paste composition, the content of the metal powder is 80 to 95% by weight and the content of the adhesive is 5 to 20% by weight.

14. The soldering method according to claim 1, wherein, based on the total weight of the activated metal solder paste composition, the content of the metal powder is 85 to 90% by weight and the content of the adhesive is 10 to 15% by weight.

15. The steps include printing the activated metal solder paste composition onto the surface of the ceramic to be soldered and baking it at 60 to 100°C for 20 to 60 minutes, The steps include: fixing and connecting the metal to be soldered with the baked solder paste to obtain the connecting member to be soldered; The process further includes the step of feeding the connecting member to be soldered into a vacuum brazing furnace, heating it, and soldering it, The ratio of the organic matter content of the connecting member to be soldered to the effective volume of the vacuum brazing furnace is 0.3 g / m ３ The soldering method according to any one of claims 1 to 14, which is as follows:

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