Method for producing active metal ceramic substrate

Abstract

To provide a method for producing an active metal ceramic substrate.SOLUTION: A method for producing an active metal ceramic substrate includes: coating a ceramic substrate with a first solder paste prepared by mixing a first metal solder material and a first organic medium, and drying the first solder paste to form a first sub-solder layer; coating the first sub-solder layer with a second solder paste prepared by mixing a second metal solder material and a second organic medium, and drying the second solder paste to form a second sub-solder layer; and disposing a conductive metal layer on the second sub-solder layer so as to form the active metal ceramic substrate. The first metal solder material includes a first active metal. The second metal solder material includes metal tin and metal copper, and selectively includes a second active metal. The first metal solder material and the second metal solder material do not contain any metal silver.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] Cross-reference to related patent applications This application claims the benefit of priority to Taiwan Patent Application No. 113104571, filed February 6, 2024. The entire contents of the above-identified application are incorporated herein by reference.

[0002]

[0010] Several references, which may include patents, patent applications, and various publications, may be cited and discussed in the description of this disclosure. Citation and / or discussion of such references is provided solely for clarity of explanation of the present disclosure and is not an admission that any such reference is "prior art" to the disclosure described herein. All references cited and discussed herein are incorporated herein by reference in their entirety to the same extent as if each reference were individually incorporated by reference.

[0003] Field of the Disclosure FIELD OF THE DISCLOSURE The present disclosure relates to methods for manufacturing metal-ceramic substrates, and more particularly to methods for manufacturing active metal-ceramic substrates. [Background technology]

[0004] With the promotion of energy conservation and carbon reduction policies in various countries, the global market for electric vehicles (EVs) is currently booming. In recent years, as major automakers have successively launched 800-volt high-voltage vehicle products, the demand for silicon carbide (SiC) ceramic substrate materials has rapidly increased.

[0005] However, the voltage, frequency, and operating temperature requirements for power devices based on silicon carbide (SiC) ceramic substrate materials are constantly increasing, which is driving demands for improved heat dissipation and reliability.

[0006] In the related art, conventional direct-bonding-copper (DBC) ceramic substrates are fabricated by eutectic bonding, and no bonding material exists between the copper layer and the ceramic substrate. However, during high-temperature operation, large thermal stress often occurs due to the difference in thermal expansion coefficients between the copper layer and the ceramic substrate (e.g., Al2O3 or AlN). This thermal stress often causes the copper layer to peel off from the surface of the ceramic substrate. Therefore, conventional direct-bonding-copper (DBC) ceramic substrates cannot meet the packaging requirements of high temperature, high power, high heat dissipation, and high reliability.

[0007] Currently, traditional direct copper bonded (DBC) ceramic substrates are gradually being replaced by active metal brazing (AMB) substrate materials. The active metal elements (e.g., Ti, Zr, Ta, Nb, V, or Hf) in the active metal brazing substrate materials can wet the side surfaces of ceramic substrates, allowing ultra-thick copper foils to be brazed to the ceramic substrates at high temperatures. The brazing layer formed between the ultra-thick copper foil and the ceramic substrate by the active metal brazing process has high bonding strength.

[0008] Conventional active metal bonding paste materials typically use silver-copper-titanium (Ag-Cu-Ti) metal composites, in which the silver content is typically greater than 50 wt % (weight percent concentration), and may even exceed 70 wt %.

[0009] The brazing temperature of conventional active metal joining paste materials employing silver-copper-titanium (Ag-Cu-Ti) metal composites is typically above 900°C (e.g., 915°C). Because the brazing layer formed from conventional active metal joining paste materials contains a high amount of silver (i.e., a precious metal), the material and manufacturing costs of active metal joining ceramic substrates remain high. Furthermore, the problem of electromigration due to silver (Ag) residue after the etching process has long been a challenge to be solved. Summary of the Invention [Problem to be solved by the invention]

[0010] In response to the above-mentioned technical shortcomings, the present disclosure provides a method for manufacturing an active metal ceramic substrate. [Means for solving the problem]

[0011] To solve the above problems, one technical aspect of the present disclosure provides a method for manufacturing an active metal ceramic substrate. This method includes the steps of: applying a first solder paste prepared by mixing a first metal solder material and a first organic medium to a side (surface) of a ceramic substrate and drying the first solder paste to form a first sub-solder layer; applying a second solder paste prepared by mixing a second metal solder material and a second organic medium to a side of the first sub-solder layer remote from the ceramic substrate and drying the second solder paste to form a second sub-solder layer; and disposing a conductive metal layer on the side of the second sub-solder layer remote from the first sub-solder layer to form the active metal ceramic substrate. The first metal solder material contains a first active metal and does not contain metallic silver (Ag). The thickness of the first sub-solder layer is 1 micrometer to 10 micrometers. The second metal solder material includes metallic tin (Sn) and metallic copper (Cu), and optionally includes a second active metal, and the second metal solder material does not include metallic silver (Ag). The thickness of the second partial solder layer is 6 micrometers to 24 micrometers.

[0012] Therefore, the method for manufacturing an active metal ceramic substrate provided by the present disclosure includes the steps of "applying a first solder paste to the side of a ceramic substrate and drying the first solder paste to form a first partial solder layer, the first solder paste being prepared by mixing a first metal solder material and a first organic medium, the first metal solder material containing a first active metal but not containing metallic silver (Ag), and the thickness of the first partial solder layer being 1 micrometer to 10 micrometers," and "applying a second solder paste to the ceramic portion of the first partial solder layer." and applying the second solder paste to the side of the active metal ceramic substrate away from the substrate, and drying the second solder paste to form a second partial solder layer, the second solder paste being prepared by mixing a second metal solder material and a second organic medium, the second metal solder material including metal tin (Sn) and metal copper (Cu), and optionally including a second active metal, the second metal solder material not including metal silver (Ag), and the thickness of the second partial solder layer being 6 micrometers to 24 micrometers, thereby eliminating the need for the use of metal silver (Ag) in the metal solder layer of the active metal ceramic substrate.

[0013] The metal solder layer, which includes the first and second solder layers, can improve the bonding strength between the ceramic substrate and the conductive metal layer. It is worth noting that the metal solder layer does not contain silver (Ag), which effectively avoids the electromigration problem caused by silver residues in related art and reduces manufacturing costs.

[0014] Finally, the active metal ceramic substrate of the present disclosure can be applied to high-power modules for energy conversion, electric vehicles and charging systems through etching circuit patterns on the ceramic substrate by exposure and development.

[0015] These and other aspects of the present disclosure will become apparent from the following description of the embodiments taken in conjunction with the following drawings and illustrations thereof, variations and modifications of which may be made without departing from the spirit and scope of the novel concepts of the present disclosure. [Brief explanation of the drawings]

[0016] The described embodiments may be better understood with reference to the following description and accompanying drawings.

[0017] [Figure 1] 1 is a flow chart of a method for manufacturing an active metal ceramic substrate according to one embodiment of the present disclosure. [Figure 2A] 1A-1C are schematic diagrams illustrating a method for manufacturing an active metal ceramic substrate according to an embodiment of the present disclosure. [Figure 2B] 1A-1C are schematic diagrams illustrating a method for manufacturing an active metal ceramic substrate according to an embodiment of the present disclosure. [Figure 2C] 1A-1C are schematic diagrams illustrating a method for manufacturing an active metal ceramic substrate according to an embodiment of the present disclosure. [Figure 2D] 1A-1C are schematic diagrams illustrating a method for manufacturing an active metal ceramic substrate according to an embodiment of the present disclosure. [Figure 2E] 1A-1C are schematic diagrams illustrating a method for manufacturing an active metal ceramic substrate according to an embodiment of the present disclosure. [Figure 3] FIG. 2 is a schematic diagram illustrating two metal solder layers formed on opposite sides of an active metal ceramic substrate according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present disclosure will be described in more detail in the following examples, which are intended to be merely illustrative, as numerous modifications and variations to the examples will be apparent to those skilled in the art. Like numbers in the drawings refer to like components throughout the drawings. As used throughout this description and the appended claims, the meanings of "a," "an," and "the" include plural references, unless clearly contradicted by context, and the meaning of "in" includes "in" and "on." Headings or sub-headings may be used herein for the convenience of the reader, but shall have no effect on the scope of the disclosure.

[0019] Terms used herein generally have their ordinary meaning in the art. In case of conflict, the present specification, including any definitions provided herein, will control. The same may be expressed in multiple ways. Alternative phrases and synonyms may be used for any term discussed herein, and no special significance is attached to whether a term is recited or discussed herein. A description with one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification, including examples of any term, is merely illustrative and in no way limits the scope and meaning of the present disclosure or the scope and meaning of any exemplified term. Similarly, the present disclosure is not limited to the various embodiments provided herein. While ordinal numbers such as "first," "second," or "third" may be used to describe various components, signals, etc., such terms are merely intended to distinguish one component / signal from another and are not intended to, and should not be construed to, impose any substantial limitations on the components, signals, etc.

[0020] [Method of manufacturing active metal ceramic substrate] As shown in FIGS. 1 and 2A to 2E, one embodiment of the present disclosure provides a method for manufacturing an active metal ceramic substrate, including steps S110, S120, S130, S140, and S150.

[0021] 1 and 2A, step S110 includes providing a ceramic substrate 1. The ceramic substrate 1 can be at least one of a silicon nitride (SiN) ceramic substrate, a silicon carbide (SiC) ceramic substrate, an aluminum nitride (AlN) ceramic substrate, and an aluminum oxide (Al2O3) ceramic substrate.

[0022] In this embodiment, the ceramic substrate 1 is preferably a silicon nitride (SiN) ceramic substrate. Furthermore, the thickness T1 of the ceramic substrate 1 is 100 micrometers to 1000 micrometers.

[0023] As shown in FIGS. 1 and 2B, step S120 includes applying a first solder paste to the side surface of the ceramic substrate 1 and drying the first solder paste at an elevated temperature to remove a substantial amount of organic solvent in the first solder paste, so that the first solder paste is formed into a first partial solder layer 2a.

[0024] The first solder paste is prepared by mixing a first metallic solder material and a first organic medium. The first metallic solder material includes a first active metal, and preferably is formed solely of the first active metal. Additionally, the first solder paste does not contain metallic silver (Ag).

[0025] In some embodiments, the first active metal can be selected from the group consisting of titanium (Ti), zirconium (Zr), tantalum (Ta), niobium (Nb), vanadium (V), hafnium (Hf), and a metal hydride of any one of the above metals. For example, the metal hydride can be selected from the group consisting of titanium hydride (TiH), zirconium hydride (ZrH), tantalum hydride (TaH), niobium hydride (NbH), vanadium hydride (VH), and hafnium hydride (HHf). Preferably, the first active metal is at least one of titanium (Ti) and titanium hydride (TiH).

[0026] In this embodiment, a first active metal is dispersed in the form of a metal powder in a first organic medium to prepare a first solder paste.

[0027] Furthermore, the first organic medium includes a paste-forming agent, a thixotropic agent, and an organic solvent.

[0028] In the first organic medium, the weight ratio of the paste-forming agent, the thixotropic agent, and the organic solvent is 20-30:1-5:50-70.

[0029] The paste-forming agent may be selected from the group consisting of silicone oil, white oil, polyvinyl alcohol, acrylic resin, nitrocellulose, ethylcellulose, dimethyl phthalate, and carboxymethylcellulose. Preferably, the paste-forming agent is ethylcellulose.

[0030] The thixotropic agent may be selected from the group consisting of polyamide wax, hardened castor oil (hydrogenated castor oil), and polyurea. Preferably, the thixotropic agent is polyamide wax.

[0031] The organic solvent may be selected from the group consisting of ethylene glycol butyl ether acetate, diethylene glycol, triethanolamine, butyl cellosolve, tert-butanol, N,N-dimethylformamide, terpineol, and nonylphenol polyethylene glycol ether. Preferably, the organic solvent is terpineol or ethylene glycol butyl ether acetate.

[0032] Specifically, in the first solder paste, the weight ratio of the first metal solder material to the first organic medium is 70:30 to 95:5, and preferably 80:20 to 90:10.

[0033] The first solder paste is preferably formulated to have a viscosity of 50 mPa·s to 300 mPa·s (at room temperature of 25°C) so that the first solder paste can be easily applied to the ceramic substrate 1 and can be easily formed into a shape.

[0034] In one embodiment of the present disclosure, the first solder paste can be applied to the side surface of the ceramic substrate 1 by screen printing and dried at a high temperature of 90°C to 110°C for 5 to 15 minutes, resulting in the evaporation of most of the organic solvent in the first solder paste and the formation of the first partial solder layer 2a. The thickness T21 of the first partial solder layer 2a is 1 micrometer to 10 micrometers, and preferably 1 micrometer to 6 micrometers.

[0035] As shown in FIGS. 1 and 2C, step S130 includes applying a second solder paste to the side of the first solder layer 2a facing away from the ceramic substrate 1, and drying the second solder paste at an elevated temperature to remove a substantial amount of the organic solvent in the second solder paste, so that the second solder paste is formed into a second solder layer 2b.

[0036] The second solder paste is prepared by mixing a second metallic solder material and a second organic medium, the second metallic solder material including metallic tin (Sn), metallic copper (Cu), and optionally including a second active metal.

[0037] Preferably, the second metal solder material is composed of metallic tin (Sn), metallic copper (Cu), and a second active metal, and the second solder paste does not contain metallic silver (Ag).

[0038] In the second metal solder material, the weight ratio of metallic tin (Sn), metallic copper (Cu), and the second active metal is 20-50:40-70:0.5-10, and preferably 32.5-42.5:52.5-62.5:2-8. For example, the weight ratio of metallic tin (Sn), metallic copper (Cu), and the second active metal is 37.5:57.5:5, although the present disclosure is not limited thereto.

[0039] In some embodiments, the second active metal can be selected from the group consisting of titanium (Ti), zirconium (Zr), tantalum (Ta), niobium (Nb), vanadium (V), hafnium (Hf), and a metal hydride of any one of the above metals. For example, the metal hydride can be selected from the group consisting of titanium hydride (TiH), zirconium hydride (ZrH), tantalum hydride (TaH), niobium hydride (NbH), vanadium hydride (VH), and hafnium hydride (HHf). Preferably, the second active metal is at least one of titanium (Ti) and titanium hydride (TiH).

[0040] In this embodiment, metallic tin (Sn), metallic copper (Cu) and a second active metal are dispersed in the form of metal powders in a second organic medium to prepare a second solder paste.

[0041] Specifically, the second organic medium includes a paste-forming agent, a thixotropic agent, and an organic solvent. In the second organic medium, the weight ratio of the paste-forming agent, the thixotropic agent, and the organic solvent is 20-30:1-5:50-70. The material types of the paste-forming agent, the thixotropic agent, and the organic solvent are the same as those of the first organic medium in the first solder paste, and will not be repeated here.

[0042] More specifically, in the second solder paste, the weight ratio of the second metal solder material to the second organic medium is 70:30 to 95:5, and preferably 80:20 to 90:10.

[0043] The second solder paste is preferably formulated to have a viscosity of 50 mPa·s to 300 mPa·s (at room temperature of 25°C) so that the second solder paste can be easily applied to the first partial solder layer 2a and shape formation can be easily achieved.

[0044] In one embodiment of the present disclosure, the second solder paste can be applied to the side of the first solder layer 2a by screen printing and dried at a high temperature of 90°C to 110°C for 5 to 15 minutes, resulting in the evaporation of most of the organic solvent in the second solder paste and the formation of the second solder layer 2b.

[0045] The thickness T22 of the second partial solder layer 2b is 6 micrometers to 24 micrometers, and preferably 18 micrometers to 24 micrometers.

[0046] Preferably, the thickness T22 of the second solder layer 2b is greater than the thickness T21 of the first solder layer 2a. The thickness ratio of the thickness T22 of the second solder layer 2b to the thickness T21 of the first solder layer 2a (i.e., T22 / T21) is in the range of 1.5 to 5, preferably in the range of 2 to 4, and more preferably in the range of 2.5 to 3.5.

[0047] The first partial solder layer 2a and the second partial solder layer 2b are joined together to form the metal solder layer 2.

[0048] In the metal solder layer 2, the total weight of the first metal solder material and the second metal solder material is 100% by weight (i.e., the total weight of the metal tin, metal copper, first active metal, and second active metal is 100% by weight), the metal tin content is in the range of 35% by weight to 70% by weight, the metal copper content is in the range of 20% by weight to 65% by weight, and the total content of the first active metal and the second active metal is in the range of 1% by weight to 20% by weight.

[0049] It is worth mentioning that in the embodiments of the present disclosure, the metal solder layer 2 does not contain metallic silver (Ag).

[0050] As shown in FIG. 2D, step S140 includes placing the conductive metal layer 3 on the side of the second solder layer 2b away from the first solder layer 2a so that the conductive metal layer 3 can be connected to the ceramic substrate 1 via the metal solder layer 2 formed by the first solder layer 2a and the second solder layer 2b, thereby forming an active metal ceramic substrate E.

[0051] The conductive metal layer 3 can be a metal copper foil, a metal aluminum foil, or a copper-aluminum alloy foil. In this embodiment, the conductive metal layer 3 is preferably a metal copper foil. In addition, the thickness T3 of the conductive metal layer 3 can be, for example, 50 micrometers to 1200 micrometers, but the present disclosure is not limited thereto.

[0052] Step S150 includes performing a high-temperature vacuum sintering process to firmly braze the conductive metal layer 3 to the ceramic substrate 1 via the metal solder layer 2 formed by the first solder layer 2a and the second solder layer 2b.

[0053] The operating temperature of the high temperature vacuum sintering process is 600°C to 900°C, preferably 700°C to 900°C.

[0054] It is worth mentioning that in the above-mentioned high-temperature vacuum sintering process, the active metal (e.g., Ti) in the first solder layer 2a can wet the surface of the ceramic substrate 1, and the active metal can react with the ceramic material (e.g., SiN) to form compounds such as titanium nitride (TiN), titanium silicon oxide (TiSi), or titanium disilicate (TiSi2), thereby improving the bonding strength between the conductive metal layer 3 and the ceramic substrate 1.

[0055] In addition, during the high-temperature vacuum sintering process, the metallic tin (Sn) and metallic copper (Cu) in the second solder layer 2b melt into a fluid state and react, resulting in good bonding strength between the conductive metal layer 3 and the ceramic substrate 1.

[0056] For example, when the operating temperature of the high-temperature vacuum sintering process is higher than 600°C, metallic tin can first react with metallic copper to form a Cu3Sn alloy. Furthermore, the Cu3Sn alloy can react with more metallic tin to form a Cu6Sn5 alloy. This allows for a stronger connection between the second solder layer 2b and the conductive metal layer 3, improving the bonding strength between the conductive metal layer 3 and the ceramic substrate 1.

[0057] According to the above configuration, the metal solder layer 2 can improve the bonding strength between the ceramic substrate 1 and the conductive metal layer 3.

[0058] Furthermore, since the metal solder layer 2 does not contain metallic silver (Ag), the problem of electromigration caused by silver residue in related art can be effectively avoided, and manufacturing costs can be reduced.

[0059] Additionally, in this embodiment, the first solder layer 2a, the second solder layer 2b, and the conductive metal layer 3 are sequentially disposed on only one side of the ceramic substrate 1. However, the present disclosure is not limited to this. For example, as shown in FIG. 3 , in another embodiment of the present disclosure, another first solder layer 2a', another second solder layer 2b', and another conductive metal layer 3' can also be sequentially disposed on the other side of the ceramic substrate 1. This allows for the formation of an active metal ceramic substrate E' in which a metal solder layer 2 is disposed on each of both side surfaces of the ceramic substrate 1. [Example]

[0060] [Experimental data and test results] Hereinafter, a detailed description will be given with reference to Example 1. However, the present disclosure is not limited thereto.

[0061] The preparation method of Example 1 includes applying a first solder paste containing a first metal solder material and a first organic medium to the side of a ceramic substrate according to the conditions shown in Table 1 and drying the first solder paste at a high temperature to form a first partial solder layer. The first metal solder material is titanium (Ti) powder (i.e., active metal), and the thickness of the first partial solder layer is 6 micrometers. In addition, the ceramic substrate is a silicon nitride ceramic substrate. Next, a second solder paste containing a second metal solder material and a second organic medium is applied to the first partial solder layer and dried at a high temperature to form a second partial solder layer. The second metal solder material contains tin (Sn) powder, copper (Cu) powder, and titanium (Ti) powder in a weight ratio of 37.5:57.5:5, and the thickness of the second partial solder layer is 18 micrometers. In each of the first and second solder pastes, the weight ratio of the metal solder material to the organic medium is 80:20. In the organic medium, the paste-forming agent is ethyl cellulose, the organic solvent is ethylene glycol butyl ether acetate, and the thixotropic agent is polyamide wax. The weight ratio of the paste-forming agent, the organic solvent, and the thixotropic agent is 25:60:15. The first solder paste and the second solder paste do not contain metallic silver. Then, a metallic copper foil is further placed on the second partial solder layer to form an active metal ceramic substrate. In Example 1, the active metal ceramic substrate is further subjected to high-temperature vacuum sintering at a brazing temperature of 855°C. Next, the temperature of the active metal ceramic substrate is lowered to room temperature, and a tensile strength test of the active metal ceramic substrate is performed.

[0062] A tensile strength tester is used to measure the tensile strength between the metal copper foil and the ceramic substrate in accordance with the JIS-C-6481 standard. The measurement temperature is 25°C. If the tensile strength exceeds 100 N / cm, the bond strength is evaluated as good. If the tensile strength is in the range of 50 N / cm to 100 N / cm, the bond strength is evaluated as fair. If the tensile strength is less than 50 N / cm, the bond strength is evaluated as poor.

[0063] [Table 1]

[0064] From the test results shown in Table 1, the activated metal ceramic substrate of Example 1 has a tensile strength of 106 N / cm, and has good tensile strength performance.

[0065] It is worth mentioning that the active metal ceramic substrate of Example 1 above can have good tensile strength performance even though the metal solder layer does not contain metallic silver, which is a breakthrough from the limitations of using metallic silver in the active metal layer in the related art.

[0066] [Beneficial Effects of the Embodiments] In conclusion, the manufacturing method of an active metal ceramic substrate provided by the present disclosure includes the steps of "applying a first solder paste to the side of a ceramic substrate and drying the first solder paste to form a first partial solder layer, the first solder paste being prepared by mixing a first metal solder material and a first organic medium, the first metal solder material containing a first active metal but not containing metallic silver (Ag), and the thickness of the first partial solder layer being 1 micrometer to 10 micrometers," and "applying a second solder paste to the ceramic portion of the first partial solder layer." and applying the second solder paste to the side of the active metal ceramic substrate away from the substrate, and drying the second solder paste to form a second partial solder layer, the second solder paste being prepared by mixing a second metal solder material and a second organic medium, the second metal solder material including metal tin (Sn) and metal copper (Cu), and optionally including a second active metal, the second metal solder material not including metal silver (Ag), and the thickness of the second partial solder layer being 6 micrometers to 24 micrometers, thereby eliminating the need for the use of metal silver (Ag) in the metal solder layer of the active metal ceramic substrate.

[0067] The metal solder layer, which includes the first and second solder layers, can improve the bonding strength between the ceramic substrate and the conductive metal layer. It is worth noting that the metal solder layer does not contain silver (Ag), which effectively avoids the electromigration problem caused by silver residues in related art and reduces manufacturing costs.

[0068] Finally, the active metal ceramic substrate of the present disclosure can be applied to high-power modules for energy conversion, electric vehicles and charging systems through etching circuit patterns on the ceramic substrate by exposure and development.

[0069] The foregoing description of exemplary embodiments of the present disclosure has been presented for purposes of illustration and description only, and is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. Many modifications and variations are possible in light of the above teaching.

[0070] The foregoing embodiments have been chosen and described to explain the principles of the disclosure and their practical application, so as to enable others skilled in the art to utilize the disclosure and various embodiments, with various modifications as may be suitable for the particular use contemplated. Alternative embodiments will become apparent to those skilled in the art to which the disclosure pertains without departing from its spirit and scope. [Explanation of symbols]

[0071] E, E': Active metal ceramic substrate 1: Ceramic substrate 2: Metal solder layer 2a, 2a': First partial solder layer 2b, 2b': Second solder layer 3, 3': Conductive metal layer T1, T21, T22, T3: Thickness

Claims

1. 1. A method for manufacturing an active metal ceramic substrate, comprising: applying a first solder paste prepared by mixing a first metallic solder material and a first organic medium to a side surface of a ceramic substrate and drying the first solder paste to form a first partial solder layer, wherein the first metallic solder material includes a first active metal and does not contain metallic silver (Ag), and the thickness of the first partial solder layer is 1 micrometer to 10 micrometers; applying a second solder paste prepared by mixing a second metallic solder material and a second organic medium to a side of the first partial solder layer away from the ceramic substrate, and drying the second solder paste to form a second partial solder layer, wherein the second metallic solder material comprises metallic tin (Sn) and metallic copper (Cu), and optionally comprises a second active metal, and the second metallic solder material does not contain metallic silver (Ag), and the thickness of the second partial solder layer is 6 micrometers to 24 micrometers; depositing a conductive metal layer on a side of the second solder layer remote from the first solder layer to form the active metal ceramic substrate; A method comprising:

2. 2. The method of claim 1, further comprising the step of performing a high temperature vacuum sintering process to braze the conductive metal layer to the ceramic substrate via the first partial solder layer and the second partial solder layer.

3. The method according to claim 2, wherein the operating temperature of the high temperature vacuum sintering process is between 600°C and 900°C.

4. 2. The method of claim 1, wherein the thickness of the second solder layer is greater than the thickness of the first solder layer, and the thickness ratio of the second solder layer to the first solder layer is in the range of 1.5 to 5.

5. 2. The method of claim 1, wherein the first portion solder layer has a thickness of 1 micrometer to 6 micrometers, and the second portion solder layer has a thickness of 18 micrometers to 24 micrometers.

6. The first active metal is titanium (Ti), zirconium (Zr), tantalum (Ta), niobium (Nb), vanadium (V), hafnium (Hf), titanium hydride (TiH ２ ), zirconium hydride (ZrH ２ ), tantalum hydride (TaH ２ ), niobium hydride (NbH), vanadium hydride (VH ２ ), and hafnium hydride (H ２ Hf ２ ), and the second active metal is selected from the group consisting of titanium (Ti), zirconium (Zr), tantalum (Ta), niobium (Nb), vanadium (V), hafnium (Hf), titanium hydride (TiH ２ ), zirconium hydride (ZrH ２ ), tantalum hydride (TaH ２ ), niobium hydride (NbH), vanadium hydride (VH ２ ), and hafnium hydride (H ２ Hf ２ 2. The method of claim 1, wherein the compound is selected from the group consisting of:

7. 2. The method of claim 1, wherein the first solder paste has a viscosity of 50 mPa·s to 300 mPa·s, and the second solder paste has a viscosity of 50 mPa·s to 300 mPa·s.

8. 2. The method of claim 1, wherein in the first solder paste, the first metal solder material is formed only by the first active metal, the first organic medium includes a paste-forming agent, a thixotropic agent, and an organic solvent, and the weight ratio of the paste-forming agent to the thixotropic agent to the organic solvent is 20-30:1-5:50-70.

9. 2. The method of claim 1, wherein in the second solder paste, the second metal solder material is formed by the metallic tin (Sn), the metallic copper (Cu), and the second active metal, and the weight ratio of the metallic tin (Sn), the metallic copper (Cu), and the second active metal is 20-50:40-70:0.5-10; and the second organic medium includes a paste-forming agent, a thixotropic agent, and an organic solvent, and the weight ratio of the paste-forming agent, the thixotropic agent, and the organic solvent is 20-30:1-5:50-70.

10. 10. The method of claim 9, wherein in the second metal solder material, the weight ratio of the metallic tin (Sn), the metallic copper (Cu), and the second active metal is 32.5-42.5:52.5-62.5:2-8.

Images