A high-performance copper alloy for electronics and its preparation method

Abstract

The present invention discloses a high-performance copper alloy for electronics and its preparation method, which relates to the technical field of electronic materials. In the present invention, copper alloy is modified by nano silver and nano tin. Under high-temperature conditions, the molten metals penetrate each other, fill the gaps between particles to make their connection tighter, thereby improving the electrical conductivity and mechanical properties of the matrix. Then, under the condition of high oxygen pressure, alloy powders mainly composed of aluminum, chromium, and tungsten carbide are melted and solidified through laser energy radiation to carry out metallurgical bonding with the matrix. First, a chromium trioxide oxide film is formed on the surface of the matrix, which reduces the oxygen activity at the oxide film interface, promotes the formation of a dense, complete and continuous aluminum oxide protective film by aluminum. Then, tungsten carbide therein forms a nucleation core, which refines the surrounding structure, improves the mechanical properties of the coating, and enhances the high-temperature oxidation resistance of the matrix.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic materials, and particularly to a high-performance copper alloy for electronics and a preparation method thereof. Background Art

[0002] With the continuous progress of human understanding and transformation ability of nature, we have entered a modern society with highly developed electrification and electronic information. Integrated circuits widely used in electronic devices, high-speed railway transportation, power transmission, advanced industrial equipment and many other aspects closely related to social development and people's livelihood construction all require the extensive participation of copper. Pure copper generally has good electrical conductivity, thermal conductivity, corrosion resistance and easy processing performance. However, its strength often cannot meet the relevant usage requirements, so it needs to be strengthened; while copper alloys are widely used in various industrial fields due to their excellent thermal conductivity, electrical conductivity and corrosion resistance, etc. But traditional copper alloys often partially sacrifice other properties such as electrical conductivity, thermal conductivity and corrosion resistance when being strengthened, and cannot form good comprehensive usage performance. And under extreme conditions of long-term work, copper alloys are prone to various wear and corrosion failure phenomena, and the failure of copper alloys will cause huge economic losses to the production and manufacturing of engineering; therefore, it is particularly necessary to invent a high-performance copper alloy for electronics. Summary of the Invention

[0003] The purpose of the present invention is to provide a high-performance copper alloy for electronics and a preparation method thereof to solve the problems existing in the prior art.

[0004] To solve the above technical problems, the present invention provides the following technical solution: A high-performance copper alloy for electronics, which is obtained by coating and modifying a copper alloy with a coating formed by laser cladding of alloy powder.

[0005] Further, the modified copper alloy is obtained by modifying the copper alloy with nano silver and nano tin under high-temperature conditions.

[0006] Further, a preparation method of a high-performance copper alloy for electronics includes the following preparation steps:

[0007] (1) Mix nano silver, nano tin and copper alloy, conduct vacuum melting, and then pour it into a mold and cool it to room temperature to obtain a modified copper alloy;

[0008] (2) Under high oxygen pressure conditions, coat and modify the copper alloy with alloy powder by laser cladding to obtain a high-performance copper alloy for electronics.

[0009] Further, the mass percentage of the components of the copper alloy in step (1) is: zinc 29%, manganese 3%, iron 2%, copper 66%.

[0010] Further, the vacuum degree in step (1) is 0.1 Pa.

[0011] Further, the melting temperature in step (1) is 950 - 1100 °C and the time is 3 - 6 h.

[0012] Further, the mass ratio of the nano - silver, nano - tin, and copper alloy in step (1) is 1:1 - 3:50.

[0013] Further, the air pressure of the high oxygen pressure in step (2) is 260 - 350 kPa.

[0014] Further, the mass percentage of the alloy powder components in step (2) is: aluminum 30%, chromium 30%, tungsten carbide 15%, nickel 20%, cobalt 5%.

[0015] Further, the laser cladding process parameters in step (2) are: laser power is 1500 W and the scanning speed is 2 mm / s.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0017] In the present invention, the conductivity of the copper alloy is enhanced by adding nano - silver. Subsequently, tin particles are added. Under high - temperature conditions, the molten metals penetrate each other, filling the voids between the particles to make their connection tighter, thereby improving the conductivity. Among them, the silver oxide on the surface of the silver particles is decomposed into silver and oxygen, and both react with tin. Part of them form intermetallic compounds, which can limit the migration movement of silver ions and improve the stability of the matrix. The other part forms tin oxide, thereby enhancing the mechanical properties of the copper alloy and achieving the effect of high - temperature oxidation resistance. Then, under the condition of high oxygen pressure, the alloy powder mainly composed of aluminum, chromium, and tungsten carbide is melted and solidified through laser energy radiation to metallurgically bond with the matrix. In the initial stage of oxidation, a chromium sesquioxide oxide film is first formed on the surface of the matrix, reducing the oxygen activity at the oxide film interface and promoting the formation of a dense, complete, and continuous aluminum oxide protective film by aluminum. Then, the tungsten carbide therein forms nucleation cores, making the surrounding tissue refined, improving the mechanical properties of the coating, and enhancing the high - temperature oxidation resistance of the matrix. Specific Embodiments

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0019] In order to more clearly illustrate the method provided by the present invention, the following examples are used for detailed description. The test methods for each index of the high - performance copper alloy for electronics manufactured in the following examples are as follows:

[0020] Conductivity: For the same-sized examples and comparative examples, first find the resistance through the four-terminal network method, and then calculate the conductivity based on the sample size.

[0021] High-temperature oxidation resistance: Take the same-sized examples and comparative examples, bake them at 300 °C for 5 h under oxygen conditions, take them out, cool them to room temperature, and record whether they change color.

[0022] Mechanical properties: Take the same-sized examples and comparative examples, and refer to JISZ2201 and JISZ2241 to test the tensile strength of the samples.

[0023] Example 1

[0024] (1) Mix nano silver, nano tin, and copper alloy, melt them at 950 °C and a vacuum of 0.1 Pa for 3 h, then pour them into a mold and cool to room temperature to obtain a modified copper alloy; the mass ratio of nano silver, nano tin, and copper alloy is 1:1:50; the mass percentage of the copper alloy components is: zinc 29%, manganese 3%, iron 2%, copper 66%.

[0025] (2) Under oxygen conditions with a pressure of 260 kPa, laser cladding the alloy powder on the modified copper alloy, with the process parameters: laser power of 1500 W, scanning speed of 2 mm / s, to obtain a high-performance copper alloy for electronics; the mass percentage of the alloy powder components is: aluminum 30%, chromium 30%, tungsten carbide 15%, nickel 20%, cobalt 5%.

[0026] Example 2

[0027] (1) Mix nano silver, nano tin, and copper alloy, melt them at 1025 °C and a vacuum of 0.1 Pa for 4 h, then pour them into a mold and cool to room temperature to obtain a modified copper alloy; the mass ratio of nano silver, nano tin, and copper alloy is 1:2:50; the mass percentage of the copper alloy components is: zinc 29%, manganese 3%, iron 2%, copper 66%.

[0028] (2) Under oxygen conditions with a pressure of 310 kPa, laser cladding the alloy powder on the modified copper alloy, with the process parameters: laser power of 1500 W, scanning speed of 2 mm / s, to obtain a high-performance copper alloy for electronics; the mass percentage of the alloy powder components is: aluminum 30%, chromium 30%, tungsten carbide 15%, nickel 20%, cobalt 5%.

[0029] Example 3

[0030] (1) Mix nano-silver, nano-tin, and copper alloy, melt at 1100 °C under a vacuum of 0.1 Pa for 6 h, then pour into a mold and cool to room temperature to obtain a modified copper alloy; the mass ratio of nano-silver, nano-tin, and copper alloy is 1:3:50; the mass percentage of the copper alloy components is: zinc 29%, manganese 3%, iron 2%, copper 66%;

[0031] (2) Under the condition of oxygen with a pressure of 350 kPa, clad the alloy powder on the modified copper alloy by laser cladding, and its process parameters: laser power is 1500 W, scanning speed is 2 mm / s, to obtain a high-performance copper alloy for electronics; the mass percentage of the alloy powder components is: aluminum 30%, chromium 30%, tungsten carbide 15%, nickel 20%, cobalt 5%.

[0032] Comparative Example 1

[0033] The difference between Comparative Example 1 and Example 2 lies in step (1). Modify step (1) as follows: Mix nano-tin and copper alloy, melt at 1025 °C under a vacuum of 0.1 Pa for 4 h, then pour into a mold and cool to room temperature to obtain a modified copper alloy; the mass ratio of nano-tin and copper alloy is 2:50; the mass percentage of the copper alloy components is: zinc 29%, manganese 3%, iron 2%, copper 66%; the remaining steps are the same as those in Example 2.

[0034] Comparative Example 2

[0035] The difference between Comparative Example 2 and Example 2 lies in step (1). Modify step (1) as follows: Mix nano-silver and copper alloy, melt at 1025 °C under a vacuum of 0.1 Pa for 4 h, then pour into a mold and cool to room temperature to obtain a modified copper alloy; the mass ratio of nano-silver and copper alloy is 1:50; the mass percentage of the copper alloy components is: zinc 29%, manganese 3%, iron 2%, copper 66%; the remaining steps are the same as those in Example 2.

[0036] Comparative Example 3

[0037] The difference between Comparative Example 3 and Example 2 is that there is no step (1); the remaining steps are the same as those in Example 2.

[0038] Comparative Example 4

[0039] The difference between Comparative Example 4 and Example 2 lies in step (2). Modify step (2) as follows: Under the condition of oxygen with a pressure of 310 kPa, clad the alloy powder on the modified copper alloy by laser cladding, and its process parameters: laser power is 1500 W, scanning speed is 2 mm / s, to obtain a high-performance copper alloy for electronics; the mass percentage of the alloy powder components is: chromium 45%, tungsten carbide 30%, nickel 20%, cobalt 5%; the remaining steps are the same as those in Example 2.

[0040] Comparative Example 5

[0041] The difference between Comparative Example 5 and Example 2 lies in the different step (2). Step (2) is changed to: Under the condition of oxygen with a pressure of 310 kPa, the alloy powder is used to coat and modify the copper alloy by laser cladding. The process parameters are: laser power of 1500 W, scanning speed of 2 mm / s, and a high-performance copper alloy for electron acquisition is obtained; the mass percentages of the components of the alloy powder are: 45% aluminum, 30% tungsten carbide, 20% nickel, and 5% cobalt; the remaining steps are the same as those in Example 2.

[0042] Comparative Example 6

[0043] The difference between Comparative Example 6 and Example 2 lies in the different step (2). Step (2) is changed to: Under the condition of oxygen with a pressure of 310 kPa, the alloy powder is used to coat and modify the copper alloy by laser cladding. The process parameters are: laser power of 1500 W, scanning speed of 2 mm / s, and a high-performance copper alloy for electron acquisition is obtained; the mass percentages of the components of the alloy powder are: 40% aluminum, 35% chromium, 20% nickel, and 5% cobalt; the remaining steps are the same as those in Example 2.

[0044] Comparative Example 7

[0045] The difference between Comparative Example 7 and Example 2 lies in the different step (2). Step (2) is changed to: The alloy powder is used to coat and modify the copper alloy by laser cladding. The process parameters are: laser power of 1500 W, scanning speed of 2 mm / s, and a high-performance copper alloy for electron acquisition is obtained; the mass percentages of the components of the alloy powder are: 30% aluminum, 30% chromium, 15% tungsten carbide, 20% nickel, and 5% cobalt; the remaining steps are the same as those in Example 2.

[0046] Comparative Example 8

[0047] The difference between Comparative Example 8 and Example 2 is that step (2) is absent; the remaining steps are the same as those in Example 2.

[0048] Effect Example

[0049] The following Table 1 gives the performance analysis results of the high-performance copper alloys for electron use in Examples 1 to 3 and Comparative Examples 1 to 7 of the present invention.

[0050] Table 1

[0051]

[0052]

[0053] From the comparison of the experimental results of the examples and comparative examples in Table 1, it can be found that in the present invention, the copper alloy is modified by nano-silver and nano-tin. Under high-temperature conditions, the molten metals penetrate each other, filling the voids between the particles to make their connection tighter, thereby improving the electrical conductivity. Among them, the silver oxide on the surface of the silver particles is decomposed into silver and oxygen, and both react with tin. Part of them form intermetallic compounds, which can limit the migration movement of silver ions and improve the stability of the matrix. The other part forms tin oxide, thereby enhancing the mechanical properties of the copper alloy and achieving the effect of high-temperature oxidation resistance. Then, under the condition of high oxygen pressure, the alloy powder mainly composed of aluminum, chromium, and tungsten carbide is melted and solidified through laser energy radiation to metallurgically bond with the matrix. First, a chromium trioxide oxide film is formed, which reduces the oxygen activity at the oxide film interface, promotes the formation of a dense, complete and continuous aluminum oxide protective film by aluminum. Then, the tungsten carbide therein forms nucleation cores, making the surrounding structure refined, improving the mechanical properties of the coating, and enhancing the high-temperature oxidation resistance of the matrix.

[0054] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be construed as limiting the claimed claim.

Claims

1. A high-performance copper alloy for electronics, characterized in that: The method comprises the following preparation steps: (1) Mixing nano silver, nano tin and copper alloy, performing vacuum melting, then pouring into a mold, and cooling to room temperature to obtain a modified copper alloy; the mass percentages of the copper alloy components are: 29% zinc, 3% manganese, 2% iron, and 66% copper; (2) Under high oxygen pressure conditions, alloy powder is coated with a modified copper alloy by laser cladding to obtain a high-performance copper alloy for electronic use; the mass percentages of the alloy powder components are: 30% aluminum, 30% chromium, 15% tungsten carbide, 20% nickel, and 5% cobalt.

2. The high-performance copper alloy for electronics according to claim 1, characterized in that: The vacuum degree in step (1) is 0.1 Pa.

3. The high-performance copper alloy for electronics according to claim 1, characterized in that: The smelting temperature in step (1) is 950-1100° C. and the smelting time is 3-6 hours.

4. The high-performance copper alloy for electronics according to claim 1, characterized in that: The mass ratio of the nano-silver, nano-tin and copper alloy in step (1) is 1:1-3:

50.

5. The high performance copper alloy for electronics according to claim 1, characterized in that: The high oxygen pressure in step (2) is 260-350 kPa.

6. The high-performance copper alloy for electronics according to claim 1, characterized in that: The laser cladding process parameters in step (2) are as follows: laser power is 1500 W and scanning speed is 2 mm / s.

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