High-conductivity fine-grain copper material, preparation method thereof and ceramic copper-clad plate

Abstract

The invention discloses a high-conductivity fine-grain copper material, which belongs to the technical field of high-performance copper materials for electronic communication and comprises the following raw materials in percentage by mass: 3 to 10 ppm of silver, 2 to 5 ppm of iron, 1 to 10 ppm of magnesium, 3 to 10 ppm of nickel, 10 to 15 ppm of titanium, 5 to 15 ppm of aluminum and the balance of Cu and inevitable impurities. The invention further discloses a preparation method of the high-conductivity fine-grain copper material and a ceramic copper-clad plate. By adding trace alloy elements, a compound phase capable of effectively inhibiting grain growth is obtained, a hot rolling process is controlled, a proper hot rolling structure is obtained, and the copper material prepared by combining an optimized cold rolling and annealing process can obtain fine and uniform grains at high temperature; and meanwhile, a trace amount of alloy elements are added, so that the influence on the conductivity of the copper can be avoided, the conductivity and high-temperature structure stability of the copper can be considered, and the high-conductivity fine-grain copper material is obtained. According to the high-conductivity fine-grain copper material, the conductivity is 100% IACS or above, and the average grain size is smaller than 150 micrometers after heat preservation is conducted for 10 min at the temperature of 1050 DEG C.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-performance copper materials for electronic communications, and in particular relates to a high-conductivity fine-crystalline copper material, a preparation method thereof, and a ceramic copper-clad plate comprising the high-conductivity fine-crystalline copper material. Background Art

[0002] Copper has high electrical and thermal conductivity. After being compounded with ceramic plates, it can be prepared into ceramic copper-clad laminates. As a carrier for carrying chips, it is widely used in parts of high-power electrical appliances. New energy vehicles and high-speed rail require that the grain size in the copper layer of ceramic copper-clad laminates is finer, and the average grain size is usually required to be within 150 microns, and the conductivity of copper is required to be above 100% IACS. However, pure copper and ceramics need to be sintered at high temperatures to achieve good interface bonding. After high-temperature sintering, the grain size in the copper layer will usually grow to several hundred microns or even millimeters, which is difficult to meet the application requirements of new energy vehicles and high-speed rail.

[0003] Generally, adding alloying elements can inhibit the growth of grains at high temperatures, but the addition of alloying elements has a great influence on the electrical conductivity of pure copper. As the content of alloying elements increases, the electrical conductivity of copper will decrease. It is difficult to simultaneously obtain high conductivity and finer grains at high temperatures in copper materials.

[0004] Therefore, how to obtain highly conductive and high temperature resistant copper is an important research direction for high performance copper. There are few reports on the effect of trace elements on the grain growth of pure copper at high temperatures. How to control the type and content of trace elements and subsequent processing technology is the key to inhibiting the grain growth of pure copper at high temperatures. Summary of the invention

[0005] In view of one or more of the above defects or improvement needs of the prior art, the present invention provides a highly conductive fine-grained copper material, a preparation method thereof and a ceramic copper-clad laminate, which can take into account both the conductivity and high-temperature structural stability of copper.

[0006] To achieve the above object, according to a first aspect of the present invention, a high-conductivity fine-grained copper material is provided, which comprises the following raw materials by mass fraction: Silver: 3~10ppm, iron: 2~5ppm, magnesium: 1~10ppm, nickel: 3~10ppm, titanium: 10~15ppm, aluminum: 5~15ppm, the balance is copper and inevitable impurities.

[0007] As a further improvement of the present invention, the total content of the impurities is lower than 15 ppm.

[0008] As a further improvement of the present invention, the electrical conductivity of the copper material is above 100% IACS, and after being kept at 1050° C. for 10 minutes, the average grain size is less than 150 μm.

[0009] According to a second aspect of the present invention, a method for preparing a high-conductivity fine-grained copper material is provided, which is used to prepare the high-conductivity fine-grained copper material, comprising the following steps: (1) Preparation of ingots: Weighing the raw materials and adding them into a furnace for smelting to obtain an ingot; (2) hot rolling: hot rolling the ingot to obtain a hot-rolled plate; The hot rolling process is as follows: after heating the furnace to 900°C-950°C, hot rolling is performed in three passes, the deformation of each pass is 45%-50%, the final rolling temperature is 500°C-550°C, and then the temperature is kept at 500°C-550°C for 30 minutes; (3) Cold rolling and annealing: The hot-rolled plate is firstly cold-rolled with a deformation amount of 60% to 70%, and then intermediate annealing is performed; then cold-rolled with a deformation amount of 90% to 95%, and finally two-step annealing is performed to obtain the high-conductivity fine-grained copper material.

[0010] The copper material described in the embodiment of the present invention includes but is not limited to copper strips, copper foils, etc.

[0011] As a further improvement of the present invention, in step (3), The intermediate annealing process is: 650°C-750°C for 5 minutes, with pure hydrogen as the protective atmosphere; The two-step annealing process is: heating to 300°C-400°C at a heating rate of 0.5°C / min, keeping the temperature for 30 minutes, and then heating to 500°C-550°C at a heating rate of 0.5°C / min, keeping the temperature for 30 minutes, and the protective atmosphere is pure hydrogen.

[0012] As a further improvement of the present invention, in step (3), During the cold rolling process with deformation of 60%~70% and deformation of 90%~95%, the working rolls are sandblasted with a sand particle diameter of 0.15~0.3mm.

[0013] It should be noted that, in the preparation method of the present invention, unless otherwise specified, the technical means used are conventional means well known to those skilled in the art. For example, in step (1), the smelting process for preparing the ingot is a conventional prior art; in step (3), how to achieve cold rolling with a deformation of 60% to 70% and cold rolling with a deformation of 90% to 95% are conventional means well known to those skilled in the art, as long as the deformation can be controlled within this range.

[0014] According to a third aspect of the present invention, there is provided a ceramic copper-clad laminate, which is obtained by high-temperature sintering of a copper material and a ceramic plate, wherein the copper material is the highly conductive fine-grained copper material, or the copper material is prepared by the method for preparing the highly conductive fine-grained copper material.

[0015] As a further improvement of the present invention, in the ceramic copper-clad laminate, the average grain size of copper is within 150 microns, and the electrical conductivity of copper is above 100% IACS.

[0016] In the preparation method of the present invention, the first stage of cold rolling, intermediate annealing and the introduction of hydrogen during the combined annealing process provide a certain number of "seeds" for the final recrystallization to form a strong texture. At the same time, trace amounts of alloying elements such as Ni, Al, Ti, Mg and Fe produce complex compounds during the intermediate annealing process. Combined with subsequent large deformation cold rolling and the final two-step low-temperature annealing, the formation of a strong texture can be achieved, thereby effectively inhibiting the growth of grains at high temperatures.

[0017] In general, the above technical solution conceived by the present invention has the following beneficial effects compared with the prior art: (1) The present invention obtains a compound phase that effectively inhibits grain growth by adding trace alloying elements, and controls the hot rolling process to obtain a suitable hot-rolled structure. The copper material prepared by combining the optimized cold rolling and annealing processes can obtain fine and uniform grains at high temperatures. At the same time, the trace addition of alloying elements can avoid affecting the electrical conductivity of copper. Therefore, the present invention can take into account both the electrical conductivity and high-temperature structure stability of copper and obtain a highly conductive fine-grained copper material.

[0018] (2) The trace alloying elements added in the present invention include Ni, Al, Ti, Mg, Fe, and Ag, which avoids the addition of rare earth or precious metal elements, has low cost and is easy to control the content.

[0019] (3) In the cold rolling process of the present invention, the roughness of the final cold-rolled surface of the copper material can be controlled by sandblasting the working rolls, thereby making surface micro-grooves to pin grain boundary migration, which can further inhibit the growth of grains at high temperatures.

[0020] (4) The preparation process of the highly conductive fine-grained copper material of the present invention is easy to control and suitable for industrial production.

[0021] (5) The high-conductivity fine-grained copper material of the present invention has a conductivity of more than 100% IACS; after being kept at 1050° C. for 10 minutes, the average grain size is less than 150 μm. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a microstructure photograph of the copper material in Example 1 of the present invention after annealing at high temperature.

[0023] Figure 2 This is a microstructure photograph of the copper material in Example 2 of the present invention after annealing at high temperature.

[0024] Figure 3This is a microstructure photograph of the copper material in Example 3 of the present invention after annealing at high temperature. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0026] In the specific embodiments of the present invention, unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art, and the materials, reagents, etc. used are all commercially available.

[0027] Example 1 The high-conductivity fine-grained copper material of this embodiment includes the following raw materials by mass fraction: silver: 3ppm, iron: 5ppm, magnesium: 10ppm, nickel: 10ppm, titanium: 10ppm, aluminum: 5ppm, and the remainder is copper and inevitable impurities. The total content of inevitable impurities is less than 15ppm.

[0028] The high-conductivity fine-grained copper material of this embodiment is prepared as follows: (1) Weighing raw materials and adding them into a melting furnace for smelting to obtain an ingot; the smelted copper ingot is used as the initial ingot, the main element is copper, and other elements are added in trace amounts; (2) Hot rolling: hot rolling the ingot to obtain hot-rolled plate; The specific hot rolling process is as follows: after the furnace temperature is raised to 900°C, three hot rolling passes are performed, the deformation of each pass is 50%, the final rolling temperature is 550°C, and then the temperature is kept at 550°C for 30 minutes.

[0029] (3) Cold rolling and annealing: The hot-rolled plate is cold-rolled with a deformation of 60%, and then annealed. The specific process is 650℃ for 5 minutes, and the protective atmosphere is pure hydrogen; then cold-rolled with a deformation of 90%, and finally two-step annealing is performed to obtain high-conductivity fine-grained copper materials; the annealing process is to heat up to 300℃ at a heating rate of 0.5℃ / min and keep it for 30 minutes, and then heat up to 550℃ at a heating rate of 0.5℃ / min and keep it for 30 minutes, and the protective atmosphere is pure hydrogen. Among them, the working rolls are sandblasted during the cold rolling process, and the sand particle diameter is 0.15~0.3mm.

[0030] The copper material prepared in this embodiment has a conductivity of 100% IACS. In addition, the metallographic photograph of the copper material prepared in this embodiment after being kept at 1050°C for 10 minutes is as follows: Figure 1As shown, it can be seen that the grain size is relatively fine, and the average grain size is about 100 microns. The results show that the copper material of this embodiment can take into account both the electrical conductivity and high temperature structural stability of copper.

[0031] Example 2 The high-conductivity fine-grained copper material of this embodiment includes the following raw materials by mass fraction: silver: 10 ppm, iron: 2 ppm, magnesium: 1 ppm, nickel: 3 ppm, titanium: 15 ppm, aluminum: 15 ppm, and the remainder is copper and inevitable impurities. The total content of inevitable impurities is less than 15 ppm.

[0032] The high-conductivity fine-grained copper material of this embodiment is prepared as follows: (1) Weighing raw materials and adding them into a melting furnace for smelting to obtain an ingot; the smelted copper ingot is used as the initial ingot, the main element is copper, and other elements are added in trace amounts; (2) Hot rolling: hot rolling the ingot to obtain hot-rolled plate; The specific hot rolling process is as follows: after the furnace temperature is raised to 950°C, three hot rolling passes are performed, the deformation of each pass is 45%, the final rolling temperature is 500°C, and then the steel is kept at 500°C for 30 minutes.

[0033] (3) Cold rolling and annealing: First, the hot-rolled plate is cold-rolled with a deformation of 70%, and then annealed. The specific process is 750℃ for 5 minutes, and the protective atmosphere is pure hydrogen; then cold-rolled with a deformation of 95%, and finally two-step annealing is performed to obtain high-conductivity fine-grained copper materials; the annealing process is to heat up to 400℃ at a heating rate of 0.5℃ / min and keep it for 30 minutes, and then heat up to 500℃ at a heating rate of 0.5℃ / min and keep it for 30 minutes, and the protective atmosphere is pure hydrogen. Among them, the working rolls are sandblasted during the cold rolling process, and the sand particle diameter is 0.15~0.3mm.

[0034] The copper material prepared in this embodiment has a conductivity of 100% IACS. In addition, the metallographic photograph of the copper material prepared in this embodiment after being kept at 1050°C for 10 minutes is as follows: Figure 2 As shown, it can be seen that the grain size is relatively fine, and the average grain size is about 100 microns. The results show that the copper material of this embodiment can take into account both the electrical conductivity and high temperature structural stability of copper.

[0035] Example 3 The high-conductivity fine-grained copper material of this embodiment includes the following raw materials by mass fraction: silver: 5ppm, iron: 3ppm, magnesium: 3ppm, nickel: 6ppm, titanium: 12ppm, aluminum: 10ppm, and the remainder is copper and inevitable impurities. The total content of inevitable impurities is less than 15ppm.

[0036] The high-conductivity fine-grained copper material of this embodiment is prepared as follows: (1) Weighing raw materials and adding them into a melting furnace for smelting to obtain an ingot; the smelted copper ingot is used as the initial ingot, the main element is copper, and other elements are added in trace amounts; (2) Hot rolling: hot rolling the ingot to obtain hot-rolled plate; The specific hot rolling process is as follows: after the furnace temperature is raised to 900°C, three hot rolling passes are performed, the deformation of each pass is 48%, the final rolling temperature is 520°C, and then the temperature is kept at 550°C for 30 minutes.

[0037] (3) Cold rolling and annealing: The hot-rolled plate is firstly subjected to cold rolling with a deformation of 65%, and then annealed, the specific process is to keep at 700°C for 5 minutes, and the protective atmosphere is pure hydrogen; then it is cold rolled with a deformation of 92%, and finally two-step annealing is performed to obtain a highly conductive fine-grained copper material; the annealing process is to heat up to 350°C at a heating rate of 0.5°C / min and keep for 30 minutes, and then heat up to 500°C at a heating rate of 0.5°C / min and keep for 30 minutes, and the protective atmosphere is pure hydrogen. In the cold rolling process, the working rolls are sandblasted, and the sand particle diameter is 0.15~0.3mm.

[0038] The copper material prepared in this embodiment has a conductivity of 100% IACS. In addition, the metallographic photograph of the copper material prepared in this embodiment after being kept at 1050°C for 10 minutes is as follows: Figure 3 As shown, it can be seen that the grain size is relatively fine, and the average grain size is about 100 microns. The results show that the copper material of this embodiment can take into account both the electrical conductivity and high temperature structural stability of copper.

[0039] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A highly conductive fine-grained copper material, It is characterized in that Calculated by mass fraction, including the following raw materials: Silver: 3~10ppm, iron: 2~5ppm, magnesium: 1~10ppm, nickel: 3~10ppm, titanium: 10~15ppm, aluminum: 5~15ppm, the balance is copper and inevitable impurities.

2. The highly conductive fine-grained copper material according to claim 1, It is characterized in that The total content of the impurities is less than 15 ppm.

3. The highly conductive fine-grained copper material according to claim 1 or 2, It is characterized in that The electrical conductivity of the copper material is above 100% IACS, and after being kept at 1050°C for 10 minutes, its average grain size is less than 150μm.

4. A method for preparing a highly conductive fine-grained copper material, for preparing the highly conductive fine-grained copper material according to any one of claims 1 to 3, It is characterized in that The steps include: (1) Preparation of ingots: Weighing the raw materials and adding them into a furnace for smelting to obtain an ingot; (2) hot rolling: hot rolling the ingot to obtain a hot-rolled plate; The hot rolling process is as follows: after heating the furnace to 900°C-950°C, hot rolling is performed in three passes, the deformation of each pass is 45%-50%, the final rolling temperature is 500°C-550°C, and then the temperature is kept at 500°C-550°C for 30 minutes; (3) Cold rolling and annealing: The hot-rolled plate is firstly cold-rolled with a deformation amount of 60% to 70%, and then intermediate annealing is performed; then cold-rolled with a deformation amount of 90% to 95%, and finally two-step annealing is performed to obtain the high-conductivity fine-grained copper material.

5. The method for preparing the highly conductive fine-grained copper material according to claim 4, It is characterized in that In step (3), The intermediate annealing process is: 650°C-750°C for 5 minutes, with pure hydrogen as the protective atmosphere; The two-step annealing process is: heating to 300°C-400°C at a heating rate of 0.5°C / min, keeping the temperature for 30 minutes, and then heating to 500°C-550°C at a heating rate of 0.5°C / min, keeping the temperature for 30 minutes, and the protective atmosphere is pure hydrogen.

6. The method for preparing the highly conductive fine-grained copper material according to claim 4 or 5, It is characterized in that In step (3), During the cold rolling process with deformation of 60%~70% and deformation of 90%~95%, the working rolls are sandblasted with a sand particle diameter of 0.15~0.3mm.

7. A ceramic copper-clad plate, obtained by high-temperature sintering of copper material and ceramic plate, It is characterized in that The copper material is the high-conductivity fine-grained copper material described in any one of claims 1-3, or the copper material is prepared by the preparation method of the high-conductivity fine-grained copper material described in any one of claims 4-6.

8. The ceramic copper clad laminate according to claim 7, It is characterized in that In the ceramic copper clad laminate, the average grain size of copper is within 150 microns, and the conductivity of copper is above 100% IACS.

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