Bimorphic and fully-compact tungsten-copper alloy electronic packaging heat sink material and preparation method thereof

Abstract

The invention discloses a bimorphic and fully-compact tungsten-copper alloy electronic packaging heat sink material and a preparation method thereof, relates to the technical field of alloy material preparation, and aims to solve the problem that the performance of a material prepared in the prior art is difficult to meet application requirements. The preparation method comprises the following steps that polyhedral tungsten powder and spherical tungsten powder are subjected to ball milling and mixing treatment, and bimorphic tungsten powder is obtained; the mass ratio of the polyhedral tungsten powder to the spherical tungsten powder is (80-95): (20-5); the bimorphic tungsten powder and copper powder are mixed in the nitrogen or argon protective atmosphere, and bimorphic tungsten-copper mixed powder is obtained; the mass ratio of the bimorphic tungsten powder to the copper powder is (7: 3)-(9: 1); the tungsten-copper mixed powder is subjected to hot isostatic pressing treatment after being subjected to sheathing treatment and degassing treatment, and the tungsten-copper alloy is obtained; and carrying out sheath removal treatment and machining treatment on the tungsten-copper alloy to obtain the tungsten-copper alloy electronic packaging heat sink material.

Description

Technical Field

[0001] The present application relates to the technical field of alloy material preparation, and in particular to a dual-morphology, fully dense tungsten-copper alloy electronic packaging heat sink material and a preparation method thereof. Background Art

[0002] Tungsten copper alloy has both the low expansion characteristics of tungsten and the high thermal conductivity of copper. Its thermal expansion coefficient and thermal and electrical conductivity can be changed by adjusting the composition of tungsten copper. It is widely used in electronic packaging and heat sink materials.

[0003] With the development of the Internet of Things, 5G base stations, data centers, and telecommunications transmission, higher and higher requirements are being placed on optical modules in the optical communication industry. Optical modules are very important active devices in 5G communication equipment. They are composed of optical devices, functional circuits, and optical interfaces. Their main function is to complete the photoelectric and electro-optical conversion of optical signals. There are three core components in optical modules: optical chips, lasers, and optical prisms. These three components have stringent requirements on the heat dissipation coefficient and thermal expansion coefficient of the carrier material. At present, the electronic packaging heat dissipation base materials for optical modules below 100G are stainless steel, copper, and Kovar alloy, but these three materials have low thermal conductivity and high thermal expansion coefficient, which cannot meet the high-speed development. However, due to the high thermal conductivity and low thermal expansion coefficient of copper-tungsten alloy, optical modules can use tungsten-copper alloy electronic packaging materials to ensure heat dissipation.

[0004] At present, the methods for preparing tungsten-copper alloys include melt infiltration, high-temperature liquid phase sintering, activated liquid phase sintering and chemical co-precipitation, but the performance of the materials prepared by the above methods is difficult to meet application requirements. Summary of the invention

[0005] The main purpose of the present application is to provide a dual-morphology, fully dense tungsten-copper alloy electronic packaging heat sink material and a preparation method thereof, aiming to solve the problem that the performance of materials produced by the prior art is difficult to meet application requirements.

[0006] To achieve the above objectives, the technical solutions adopted in the embodiments of the present application are as follows: In a first aspect, an embodiment of the present application provides a method for preparing a dual-morphology, fully dense tungsten-copper alloy electronic packaging heat sink material, comprising the following steps: The polyhedral tungsten powder and the spherical tungsten powder are subjected to ball milling and mixing treatment to obtain dual-morphology tungsten powder; the mass ratio of the polyhedral tungsten powder to the spherical tungsten powder is 80-95:20-5; The dual-morphology tungsten powder and the copper powder are mixed in a nitrogen or argon protective atmosphere to obtain a dual-morphology tungsten-copper mixed powder; the mass ratio of the dual-morphology tungsten powder to the copper powder is 7:3-9:1; The dual-morphology tungsten-copper mixed powder is subjected to sheathing and degassing treatments, and then subjected to hot isostatic pressing to obtain a tungsten-copper alloy; the tungsten-copper alloy is subjected to sheathing removal and mechanical processing to obtain a tungsten-copper alloy electronic packaging heat sink material.

[0007] As some optional embodiments of the present application, the average particle size of the polyhedral tungsten powder is 4 μm-8 μm.

[0008] As some optional embodiments of the present application, the average particle size of the spherical tungsten powder is 5 μm-50 μm.

[0009] As some optional implementations of the present application, the copper powder is electrolytic copper powder with a particle size D90<10μm.

[0010] As some optional embodiments of the present application, the rotation speed of the ball milling mixing process is 50r / min-200r / min, and the processing time is 1h-6h.

[0011] As some optional embodiments of the present application, the dual-morphology tungsten powder and the copper powder are mixed in a nitrogen or argon protective atmosphere for 4 hours to 10 hours.

[0012] As some optional embodiments of the present application, the temperature of the degassing treatment is 400°C-500°C, and the time of the degassing treatment is 15h-30h.

[0013] As some optional embodiments of the present application, the vacuum degree of the encapsulation treatment is 10 -2 Pa-10 -4 Pa.

[0014] As some optional embodiments of the present application, the medium of the hot isostatic pressing treatment is argon, the temperature is 900°C-1200°C, the pressure is 100MPa-180MPa, and the time is 1h-6h.

[0015] In the second aspect, an embodiment of the present application provides a dual-morphology, fully dense tungsten-copper alloy electronic packaging heat sink material, which is prepared by the preparation method as described above. The thermal conductivity of the tungsten-copper alloy electronic packaging heat sink material is 240W / (m·K) and the density is ≥99.9%.

[0016] Compared with the prior art, the beneficial effects of the present application are as follows: unlike the traditional method of using a single-form tungsten powder, the present application combines polyhedral tungsten powder and spherical tungsten powder. Polyhedral tungsten powder has complex surface features, which helps to improve the interlocking performance and bonding between particles, while spherical tungsten powder can effectively improve mixing uniformity and filling density due to its fluidity and uniform particle size distribution; the combination of the two enhances the mechanical properties of the material while ensuring thermal conductivity. And by precisely controlling the ratio of polyhedral and spherical tungsten powder (80-95:20-5), as well as the mass ratio of dual-form tungsten powder and copper powder (7:3-9:1), the optimization of thermal conductivity is achieved; at the same time, this ratio design also ensures the maximization of the material density, reaching 99.9% or higher. And the present application uses inert gas protection during the mixing stage, which can effectively prevent the oxidation of the material, thereby improving the thermal conductivity and mechanical stability of the material; compared with the traditional method of mixing in air, this treatment method can reduce the impact of impurities on the material. In addition, this application also eliminates micropores and defects in the material through a high temperature and high pressure environment to ensure the density and uniformity inside the material. Traditional sintering methods may not be able to achieve such an effect, but hot isostatic pressing can significantly improve the microstructure of the alloy and improve the comprehensive performance of the material. It can be seen that while traditional tungsten-copper alloy materials improve thermal conductivity, they may suffer from reduced strength and stability due to insufficient density. The technical solution of this application achieves a high thermal conductivity of 240W / (m·K) through fine powder selection, proportioning and processing technology, while maintaining a high density of ≥99.9%. This ensures excellent heat dissipation performance and structural stability in electronic packaging applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of a process for preparing a dual-morphology, fully dense tungsten-copper alloy electronic packaging heat sink material involved in an embodiment of the present application; Figure 2 This is a metallographic diagram of a tungsten-copper alloy electronic packaging heat sink material at a magnification of 500 involved in an embodiment of the present application; Figure 3 This is a metallographic diagram of a tungsten-copper alloy electronic packaging heat sink material at a magnification of 200 involved in an embodiment of the present application; Figure 4 This is a metallographic diagram of the tungsten-copper alloy electronic packaging heat sink material at a magnification of 100 involved in the embodiment of the present application. DETAILED DESCRIPTION

[0018] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0019] As mentioned above, tungsten copper alloy combines the low expansion of tungsten and the high thermal conductivity of copper. Its performance can be optimized by adjusting the composition and is widely used in electronic packaging and heat sink materials. With the development of the Internet of Things and 5G technology, the demand for optical modules has increased, and its core components have strict requirements on heat dissipation and thermal expansion coefficient. Existing materials such as stainless steel, copper, and Kovar alloy have low thermal conductivity and high expansion coefficient, which are not suitable for high-speed development. Tungsten copper alloy has become an ideal material for electronic packaging of optical modules due to its high thermal conductivity and low expansion coefficient.

[0020] At present, the methods for preparing tungsten-copper alloys include melt infiltration, high-temperature liquid phase sintering, activated liquid phase sintering and chemical co-precipitation, but the performance of materials prepared by these methods cannot fully meet application requirements.

[0021] For example, the infiltration method involves pressing tungsten powder into a billet and pre-sintering it at a specific temperature to form a porous tungsten matrix skeleton with a specific density and strength. Subsequently, a tungsten-copper alloy is prepared by melting the metallic copper with a lower melting point and infiltrating it into the tungsten skeleton. However, since the pore connectivity and size consistency of the tungsten skeleton are difficult to accurately control, the infiltration of the copper phase only depends on the action of capillary force, resulting in poor uniformity of the prepared material. In addition, the residual void problem inherent in the infiltration method makes it impossible to achieve a fully dense state. Machining is required after infiltration to remove excess metallic copper, which not only increases the subsequent machining cost, but also reduces the yield rate. At the same time, this method is not conducive to the production of parts with complex shapes.

[0022] For example, the high-temperature liquid phase sintering method is a process of preparing tungsten-copper composite materials by mixing tungsten powder and copper powder in a certain proportion, pressing them, and then sintering them in liquid phase. The traditional process usually performs sintering at a high temperature of 300°C above the melting point of copper to achieve the densification of the material. The advantage of this method is that the production process is simple, but its disadvantages include high sintering temperature, long sintering time, large amount of copper volatilization, poor sintering performance and low sintering density (only 90% to 95% of the theoretical density), which cannot meet specific use requirements. Therefore, in order to increase the density of the material, it is usually necessary to add post-processing steps such as re-pressing, hot pressing, and hot calcining after liquid phase sintering, which undoubtedly increases the complexity of the process and limits its scope of application.

[0023] For example, the activated liquid phase sintering method promotes the dissolution of the tungsten phase insoluble in copper in the copper phase by adding a trace amount of a third metal element such as Pd, Ni, Co, and Fe to the tungsten copper material, and forms a phase containing these metal elements during the liquid phase sintering process. This method effectively reduces the sintering temperature, shortens the sintering time, and significantly improves the sintering density. However, the addition of the activator will affect the electrical and thermal conductivity of the high-conductivity phase copper, thereby causing the thermal and electrical conductivity of the material to decrease, which is unfavorable for microelectronic materials with high electrical and thermal conductivity requirements. Therefore, the materials prepared by this method are more suitable for applications where electrical and thermal conductivity requirements are not high.

[0024] For example, the chemical coprecipitation method involves adding concentrated nitric acid to a copper nitrate solution under stirring conditions, then adding the mixed solution to a (NH4)2WO4 solution, and performing a chemical coprecipitation reaction under electromagnetic stirring to generate a mixed precipitate. After calcination in a muffle furnace and reduction in a hydrogen furnace, a tungsten-copper composite powder is obtained, and finally a tungsten-copper composite material is obtained by compression molding and sintering in a hydrogen furnace. The tungsten-copper composite material prepared by the chemical coprecipitation method has better thermal and electrical conductivity. However, the method is complicated and difficult to control, and has high requirements for equipment and environment, which limits its promotion and application.

[0025] Based on this, the present application aims to propose a dual-phase structured, fully dense tungsten-copper alloy electronic packaging heat sink material and its corresponding preparation method. The method successfully prepares a fully dense and highly thermally conductive electronic packaging tungsten-copper alloy material by ball milling tungsten powder, mixing tungsten powder with electrolytic copper powder, and hot isostatic pressing to meet the performance requirements of the heat dissipation base of the optical module.

[0026] Specifically, the preparation method of the dual-morphology, fully dense tungsten-copper alloy electronic packaging heat sink material described in the embodiment of the present application is as follows: Figure 1 As shown, the following steps are included: Step S10, ball-milling and mixing the polyhedral tungsten powder and the spherical tungsten powder to obtain dual-morphology tungsten powder; the mass ratio of the polyhedral tungsten powder to the spherical tungsten powder is 80-95:20-5; the average particle size of the polyhedral tungsten powder is 4μm-8μm, the average particle size of the spherical tungsten powder is 5μm-50μm, the rotation speed of the ball milling mixing treatment is 50r / min-200r / min, and the treatment time is 1h-6h.

[0027] Step S20, mixing the dual-morphology tungsten powder and the copper powder in a nitrogen or argon protective atmosphere to obtain a dual-morphology tungsten-copper mixed powder; the mass ratio of the dual-morphology tungsten powder to the copper powder is 7:3-9:1; the copper powder is electrolytic copper powder with a particle size D90 <10μm, and the dual-morphology tungsten powder and the copper powder are mixed in a nitrogen or argon protective atmosphere for 4h-10h.

[0028] Step S30, after the dual-morph tungsten-copper mixed powder is subjected to sheathing and degassing treatment, hot isostatic pressing treatment is performed to obtain a tungsten-copper alloy; after the tungsten-copper alloy is subjected to sheathing removal treatment and mechanical processing treatment, a tungsten-copper alloy electronic packaging heat sink material is obtained, the temperature of the degassing treatment is 400°C-500°C, the time of the degassing treatment is 15h-30h, and the vacuum degree of the sheathing treatment is 10 -2 Pa-10 -4Pa; the medium of the hot isostatic pressing treatment is argon, the temperature is 900°C-1200°C, the pressure is 100MPa-180MPa, and the time is 1h-6h.

[0029] The thermal conductivity of the tungsten-copper alloy electronic packaging heat sink material prepared by the above method is 240W / (m·K), and the density is ≥99.9%; the metallographic image of the tungsten-copper alloy electronic packaging heat sink material is as follows Figure 2-Figure 4 As shown, the metallographic image of the tungsten copper alloy electronic packaging heat sink material at 500 times is as follows Figure 2 As shown, the metallographic image of the tungsten copper alloy electronic packaging heat sink material at 200 times is as follows Figure 3 As shown, the metallographic image of the tungsten copper alloy electronic packaging heat sink material at 100 times is as follows Figure 4 shown.

[0030] The technical solution described in this application will be described in detail below with reference to specific embodiments: Example 1 The polyhedral tungsten powder and the spherical tungsten powder are ball-milled and mixed to obtain dual-morphology tungsten powder; the mass ratio of the polyhedral tungsten powder to the spherical tungsten powder is 85:15; the average particle size of the polyhedral tungsten powder is 7.5 μm, the average particle size of the spherical tungsten powder is 25 μm, the rotation speed of the ball-milling mixing treatment is 50 r / min-200 r / min, and the treatment time is 1 h-6 h.

[0031] The dual-morphology tungsten powder and the copper powder are mixed in a nitrogen or argon protective atmosphere to obtain a dual-morphology tungsten-copper mixed powder; the mass ratio of the dual-morphology tungsten powder to the copper powder is 9:1; the copper powder is electrolytic copper powder with a particle size of D90=9.5μm, and the dual-morphology tungsten powder and the copper powder are mixed in a nitrogen or argon protective atmosphere for 8h.

[0032] The dual-morphology tungsten-copper mixed powder is subjected to a sheathing treatment and a degassing treatment, and then subjected to a hot isostatic pressing treatment to obtain a tungsten-copper alloy; the tungsten-copper alloy is subjected to a sheathing removal treatment and a mechanical processing treatment to obtain a tungsten-copper alloy electronic packaging heat sink material, wherein the degassing treatment temperature is 400°C-500°C, the degassing treatment time is 15h-30h, and the sheathing treatment vacuum degree is 10 -3 Pa; the medium of the hot isostatic pressing treatment is argon, the temperature is 1150°C, the pressure is 160MPa, and the time is 3h.

[0033] The thermal conductivity of the tungsten-copper alloy electronic packaging heat sink material prepared by the above method is 240W / (m·K) and the density is 99.90%.

[0034] Example 2 The polyhedral tungsten powder and the spherical tungsten powder are ball-milled and mixed to obtain dual-morphology tungsten powder; the mass ratio of the polyhedral tungsten powder to the spherical tungsten powder is 90:10; the average particle size of the polyhedral tungsten powder is 6.5 μm, the average particle size of the spherical tungsten powder is 20 μm, the rotation speed of the ball-milling mixing treatment is 50 r / min-200 r / min, and the treatment time is 1 h-6 h.

[0035] The dual-morphology tungsten powder and the copper powder are mixed in a nitrogen or argon protective atmosphere to obtain a dual-morphology tungsten-copper mixed powder; the mass ratio of the dual-morphology tungsten powder to the copper powder is 8:2; the copper powder is electrolytic copper powder with a particle size of D90=8μm; the dual-morphology tungsten powder and the copper powder are mixed in a nitrogen or argon protective atmosphere for 6 hours.

[0036] The dual-morphology tungsten-copper mixed powder is subjected to a sheathing treatment and a degassing treatment, and then subjected to a hot isostatic pressing treatment to obtain a tungsten-copper alloy; the tungsten-copper alloy is subjected to a sheathing removal treatment and a mechanical processing treatment to obtain a tungsten-copper alloy electronic packaging heat sink material, wherein the degassing treatment temperature is 400°C-500°C, the degassing treatment time is 15h-30h, and the sheathing treatment vacuum degree is 10 -4 Pa; the medium of the hot isostatic pressing treatment is argon, the temperature is 1080°C, the pressure is 140MPa, and the time is 2.5h.

[0037] The thermal conductivity of the tungsten-copper alloy electronic packaging heat sink material prepared by the above method is 245W / (m·K) and the density is 99.95%.

[0038] Example 3 The polyhedral tungsten powder and the spherical tungsten powder are ball-milled and mixed to obtain dual-morphology tungsten powder; the mass ratio of the polyhedral tungsten powder to the spherical tungsten powder is 95:5; the average particle size of the polyhedral tungsten powder is 5 μm, the average particle size of the spherical tungsten powder is 10 μm, the rotation speed of the ball-milling mixing treatment is 50 r / min-200 r / min, and the treatment time is 1 h-6 h.

[0039] The dual-morphology tungsten powder and the copper powder are mixed in a nitrogen or argon protective atmosphere to obtain a dual-morphology tungsten-copper mixed powder; the mass ratio of the dual-morphology tungsten powder to the copper powder is 7:3; the copper powder is electrolytic copper powder with a particle size of D90=8μm, and the dual-morphology tungsten powder and the copper powder are mixed in a nitrogen or argon protective atmosphere for 5 hours.

[0040] The dual-morphology tungsten-copper mixed powder is subjected to a sheathing treatment and a degassing treatment, and then subjected to a hot isostatic pressing treatment to obtain a tungsten-copper alloy; the tungsten-copper alloy is subjected to a sheathing removal treatment and a mechanical processing treatment to obtain a tungsten-copper alloy electronic packaging heat sink material, wherein the degassing treatment temperature is 400°C-500°C, the degassing treatment time is 15h-30h, and the sheathing treatment vacuum degree is 10 -4 Pa; the medium of the hot isostatic pressing treatment is argon, the temperature is 1070°C, the pressure is 120MPa, and the time is 4h.

[0041] The thermal conductivity of the tungsten-copper alloy electronic packaging heat sink material prepared by the above method is 255W / (m·K) and the density is 99.96%.

[0042] Comparative Example 1 The CuW80 alloy was prepared by forming tungsten powder with an average particle size of 6μm and infiltrating at 1350℃ for 4h. The thermal conductivity was 190W / (m·K) and the density was 97%.

[0043] Comparative Example 2 After mixing tungsten powder with an average particle size of 2μm and copper powder with an average particle size of 10μm, the mixture was sintered at 1350℃ for 2h. The CuW80 alloy prepared by this liquid phase sintering process had a thermal conductivity of 160W / (m·K) and a density of 90%-95%.

[0044] Comparative Example 3 The tungsten-copper oxide composite powder was obtained by mixing ammonium metatungstate solution with copper nitrate solution, spray drying and calcining, and the submicron tungsten-copper composite powder was obtained by hydrogen reduction. The CuW80 composite powder prepared by this method was sintered at 1200℃ for 1h, and the obtained CuW80 alloy had a thermal conductivity of 190 W / (m·K) and a density of 97%.

[0045] It can be seen that the preparation method of the dual-morphology, fully dense tungsten-copper alloy electronic packaging heat sink material described in this application has the following improvements compared to the prior art: On the one hand, in the preparation of tungsten-copper alloy, the prior art usually uses a single form of tungsten powder (such as spherical tungsten powder or polyhedral tungsten powder). Spherical tungsten powder has good fluidity and high formability, while polyhedral tungsten powder has advantages in improving the density of the alloy. The prior art generally does not fully utilize the complementary properties of the two tungsten powder forms. However, the present application obtains "dual-form tungsten powder" by ball milling and mixing polyhedral tungsten powder with spherical tungsten powder, and clarifies the mass ratio of the two (80-95:20-5). That is, by combining these two forms of tungsten powder, better powder dispersion and uniformity can be achieved during the preparation process, thereby improving the density and mechanical properties of the final alloy. Especially during hot isostatic pressing, the combination of dual-form tungsten powder helps to achieve higher density and reduce porosity at lower pressure.

[0046] Secondly, the prior art often requires the preparation of tungsten-copper alloys in an inert gas (such as argon) or protective atmosphere to prevent the reaction of tungsten powder with oxygen. In the prior art, although the use of protective atmosphere is relatively common, there are few studies on atmosphere control during the mixing of different powder forms. The present application, on the other hand, mixes dual-form tungsten powder with copper powder in a nitrogen or argon protective atmosphere, that is, by explicitly using a nitrogen or argon protective atmosphere, effectively avoids the reaction of tungsten powder with oxygen in the air, ensures the purity of the powder mixture, reduces the formation of oxides, and improves the stability and performance of the alloy. Especially for the mixing of dual-form tungsten powder, this atmosphere control helps to improve the bonding quality of tungsten powder and copper powder, and avoids the impact of oxidation on the thermal conductivity and density of the heat sink material.

[0047] On the third aspect, sheathing and degassing are not common in the preparation of tungsten copper alloys. In the prior art, sheathing is often used to prevent oxidation of materials and the entry of impurities during high-temperature sintering, while degassing is used to remove gas components in the powder. The present application uses sheathing and degassing before hot isostatic pressing. That is, by sheathing the mixed powder, the tungsten copper powder can be effectively protected from reacting with external gases at high temperatures to ensure the purity of the alloy. Degassing helps to remove gases (such as moisture and oxygen) in the powder, reduce porosity and impurities in the alloy, and thus improve the density and thermal conductivity of the alloy. The combination of these two steps effectively improves the performance of the final tungsten copper alloy material, especially in the application of heat sink materials, which can significantly improve thermal conductivity and mechanical strength.

[0048] Fourthly, hot isostatic pressing is a common method to improve the density and mechanical properties of powder metallurgy materials, but the existing technology has not been fully optimized for the heat sink application of tungsten-copper alloy materials. This application uses hot isostatic pressing (HIP) treatment technology to further improve the density of tungsten-copper alloys; that is, the hot isostatic pressing treatment in the technical solution described in this application can fully eliminate the gaps between powders under high temperature and high pressure conditions, significantly improve the density of the material, and then improve the thermal conductivity. The density of tungsten-copper alloy reaches ≥99.9%. This high density makes the thermal conductivity of the material close to the theoretical maximum value, which improves the thermal management ability of the material in high-power electronic packaging.

[0049] Fifthly, the thermal conductivity of existing tungsten-copper alloy materials is usually in a relatively low range (e.g., 150-200 W / (m·K)), and the improvement of density is usually limited by the limitations of powder morphology and molding process. The tungsten-copper alloy electronic packaging heat sink material finally prepared in this application has a thermal conductivity of 240W / (m·K) and a density ≥99.9%. That is, through the application of dual-morphology tungsten powder, atmosphere control, sheathing treatment, degassing treatment, and optimization of hot isostatic pressing, the present invention successfully improves the thermal conductivity of tungsten-copper alloy to 240 W / (m·K), which is significantly better than the prior art. This enables the material to have better thermal management capabilities in electronic packaging and heat sink applications, can dissipate heat more effectively, and improve the reliability and stability of electronic equipment.

[0050] That is to say, the application of existing tungsten-copper alloy materials in the field of heat sinks is usually limited by low thermal conductivity or low density, which limits its application in high-power electronic devices. The tungsten-copper alloy electronic packaging heat sink material prepared in this application has high thermal conductivity and high density, and has broad application prospects; specifically, the high-performance tungsten-copper alloy material of this application can effectively improve the thermal management capability of electronic packaging, and is particularly suitable for high-power, high-heat flux density electronic devices such as power semiconductors, lasers, LED lamps and other fields. The use of this material can extend the service life of electronic devices and improve their stability and efficiency.

[0051] That is, in the process of preparing tungsten-copper alloy materials, the technical solution described in this application significantly improves the density (≥99.9%) and thermal conductivity (240 W / (m·K)) of tungsten-copper alloy through innovative dual-morph tungsten powder use, mixing in nitrogen or argon protective atmosphere, jacketing, degassing and hot isostatic pressing. This new material has excellent thermal management performance in the field of electronic packaging heat sinks and has broad application prospects. It solves the problem of low density and thermal conductivity of tungsten-copper alloy in the prior art and is an innovative solution with significant progress in material design and processing technology.

[0052] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing a dual-morphology, fully dense tungsten-copper alloy electronic packaging heat sink material, characterized in that: The following steps are involved: The polyhedral tungsten powder and the spherical tungsten powder are subjected to ball milling and mixing treatment to obtain dual-morphology tungsten powder; the mass ratio of the polyhedral tungsten powder to the spherical tungsten powder is 80-95:20-5; The dual-morphology tungsten powder and the copper powder are mixed in a nitrogen or argon protective atmosphere to obtain a dual-morphology tungsten-copper mixed powder; the mass ratio of the dual-morphology tungsten powder to the copper powder is 7:3-9:1; The dual-morphology tungsten-copper mixed powder is subjected to sheathing and degassing treatments, and then subjected to hot isostatic pressing to obtain a tungsten-copper alloy; the tungsten-copper alloy is subjected to sheathing removal and mechanical processing to obtain a tungsten-copper alloy electronic packaging heat sink material.

2. The method for preparing the dual-morphology, fully dense tungsten-copper alloy electronic packaging heat sink material according to claim 1, characterized in that: The average particle size of the polyhedral tungsten powder is 4 μm-8 μm.

3. The method for preparing the dual-morphology, fully dense tungsten-copper alloy electronic packaging heat sink material according to claim 1, characterized in that: The average particle size of the spherical tungsten powder is 5 μm-50 μm.

4. The method for preparing the dual-morphology, fully dense tungsten-copper alloy electronic packaging heat sink material according to claim 1, characterized in that: The copper powder is electrolytic copper powder, and the particle size D90 is less than 10 μm.

5. The method for preparing the dual-morphology, fully dense tungsten-copper alloy electronic packaging heat sink material according to claim 1, characterized in that: The rotation speed of the ball milling mixing process is 50r / min-200r / min, and the processing time is 1h-6h.

6. The method for preparing the dual-morphology, fully dense tungsten-copper alloy electronic packaging heat sink material according to claim 1, characterized in that: The dual-morphology tungsten powder and the copper powder are mixed in a nitrogen or argon protective atmosphere for 4 hours to 10 hours.

7. The method for preparing the dual-morphology, fully dense tungsten-copper alloy electronic packaging heat sink material according to claim 1, characterized in that: The temperature of the degassing treatment is 400° C.-500° C., and the time of the degassing treatment is 15 h-30 h.

8. The method for preparing the dual-morphology, fully dense tungsten-copper alloy electronic packaging heat sink material according to claim 1, characterized in that: The vacuum degree of the encapsulation treatment is 10 -2 Pa-10 -4 Pa.

9. The method for preparing the dual-morphology, fully dense tungsten-copper alloy electronic packaging heat sink material according to claim 1, characterized in that: The medium of the hot isostatic pressing treatment is argon, the temperature is 900° C.-1200° C., the pressure is 100 MPa-180 MPa, and the time is 1 h-6 h.

10. A dual-morphology, fully dense tungsten-copper alloy electronic packaging heat sink material, characterized in that: The tungsten-copper alloy electronic packaging heat sink material is prepared by the preparation method according to any one of claims 1 to 9, and the thermal conductivity of the tungsten-copper alloy electronic packaging heat sink material is 240W / (m·K) and the density is ≥99.9%.

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