W-cu micro-laminated composite material based on electroless copper plating and preparation method thereof

Abstract

This invention discloses a method for preparing W-Cu micro-layered composite materials based on chemical copper plating, comprising the following steps: Step 1, ball milling W powder to form flakes, obtaining flake-shaped W powder; Step 2, preparing a copper plating solution; Step 3, adding the flake-shaped W powder to the copper plating solution for reaction, followed by repeated filtration and washing with deionized water, and then freeze-drying to obtain a W-Cu composite powder with Cu-coated flake-shaped W powder; Step 4, sintering the Cu-coated flake-shaped W powder under vacuum hot pressing to obtain the W-Cu micro-layered composite material. The W-Cu micro-layered composite material obtained by this invention improves thermal conductivity while reducing the coefficient of thermal expansion.

Description

Technical Field

[0001] This invention belongs to the field of composite material preparation technology, specifically relating to a method for preparing W-Cu micro-layer composite materials based on chemical copper plating, and also relating to W-Cu micro-layer composite materials based on chemical copper plating. Background Technology

[0002] With the rapid development of modern electronic information technology and high-power electronic devices, the integration and power density of devices are constantly increasing, placing more stringent requirements on the comprehensive performance of thermal management materials. Heat sink materials for electronic packaging not only need to possess excellent thermal conductivity to achieve rapid heat conduction and efficient heat dissipation during device operation, but also need to have a low coefficient of thermal expansion to ensure good dimensional stability and high-temperature adaptability of the devices.

[0003] W-Cu composites, possessing both the low coefficient of thermal expansion of W and the high thermal conductivity of Cu, along with certain mechanical strength and good thermal shock resistance, have become one of the most widely used materials in the field of electronic packaging. However, traditional homogeneous W-Cu composites exhibit a mutually restrictive relationship between thermal conductivity and thermal expansion properties, making it difficult to achieve further synergistic optimization of their performance. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing W-Cu micro-layer composite materials based on chemical copper plating, thereby solving the problem that it is difficult to achieve synergistic optimization of the thermal conductivity and thermal expansion properties of existing W-Cu composite materials.

[0005] Another object of the present invention is to provide a W-Cu micro-layer composite material based on chemical copper plating.

[0006] The technical solution adopted in this invention is a method for preparing W-Cu micro-layer composite materials based on chemical copper plating, the steps of which are as follows: Step 1: The W powder is subjected to a lamellarization process by ball milling to obtain flake-shaped W powder; Step 2: Prepare the copper plating solution; Step 3: Add the flake W powder obtained in Step 1 to the copper plating solution obtained in Step 2 for reaction. After the reaction, filter and wash repeatedly with deionized water, and then freeze dry to obtain W-Cu composite powder with Cu-coated flake W powder. Step 4: The W-Cu composite powder with Cu-coated flake W powder obtained in Step 3 is sintered by vacuum hot pressing to obtain W-Cu micro-layer composite material.

[0007] The invention is further characterized by: In step 1, the ball milling is carried out using high-energy ball milling or plasma ball milling, with a ball-to-material ratio of 10~50:1, a ball milling speed of 300r / min~1200r / min, and a ball milling time of 3h~12h.

[0008] In step 1, the average particle size of the flake W powder is 10μm~50μm.

[0009] Step 2 is as follows: Mix anhydrous copper sulfate, potassium sodium tartrate and deionized water, then add 2,2'-bipyridine to obtain a mixed solution. Heat the mixed solution to a set temperature, add NaOH solution to adjust the pH value of the mixed solution to 10~13, and then add glyoxylic acid solution to obtain a copper plating solution.

[0010] In step 2, the molar ratio of anhydrous copper sulfate, potassium sodium tartrate, and glyoxylic acid per liter of deionized water is 1:1~2:0.5~1.5; The mass ratio of 2,2'-bipyridine to deionized water is 1:50000.

[0011] In step 2, the temperature is set to 40℃~60℃.

[0012] In step 3, the reaction time is 1 min to 10 min.

[0013] In step 4, the process parameters for vacuum hot pressing sintering are: vacuum degree below 10. -3 Pa, temperature is 850℃~1050℃, holding time is 20min~50min, pressing pressure is 20MPa~100MPa.

[0014] Another technical solution adopted in this invention is a W-Cu micro-layer composite material based on chemical copper plating, which is prepared by the above-mentioned preparation method.

[0015] The beneficial effects of this invention are: (1) The present invention provides a method for preparing W-Cu micro-layer composite material based on chemical copper plating. By combining refractory metal tungsten (W) with copper (Cu) which has excellent thermal conductivity and good ductility, the high melting point, high strength, high hardness and thermal stability of W and the high thermal conductivity and plasticity of Cu are taken into account. Under the premise of ensuring the structural strength and dimensional stability of the material, the synergistic optimization of thermal and mechanical properties is achieved, thereby meeting the comprehensive requirements of heat sink materials for heat dissipation efficiency and structural reliability in electronic packaging. (2) The preparation method of W-Cu micro-layer composite material based on chemical copper plating method of the present invention deposits a copper layer on the surface of tungsten powder and constructs a micro-scale layered structure in the subsequent forming and sintering process, so that the copper phase forms a continuous or semi-continuous heat conduction channel in the inner direction of the layer, thereby significantly improving the heat conduction performance in this direction; at the same time, the tungsten phase, as a rigid skeleton, effectively constrains the thermal expansion behavior of the copper phase and reduces the overall thermal expansion coefficient of the material. (3) The preparation method of W-Cu micro-layer composite material based on chemical copper plating method of the present invention draws on the biomimetic structural characteristics of the alternating "soft-hard" structure of natural seashell nacre layer to construct a W-Cu micro-layer structure with multiple interfaces. The multi-interface structure helps to suppress crack propagation, alleviate thermal stress concentration and promote energy dissipation, thereby improving the service stability and thermal fatigue resistance of the material under thermal cycling conditions. (4) The present invention provides a method for preparing W-Cu micro-layer composite material based on chemical copper plating. The method uses chemical copper plating to prepare W-Cu composite powder with Cu-coated flake W powder, thereby obtaining W-Cu micro-layer composite material with good structural uniformity. This process alleviates the structural construction problem caused by the difference in physical properties between W and Cu to a certain extent, and provides a feasible technical approach for controlling the heat transfer path in the micro-layer structure. Attached Figure Description

[0016] Figure 1 This is a microstructure diagram of the W-Cu microlayered composite material obtained in Example 4 of the present invention. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0018] The present invention discloses a method for preparing W-Cu micro-layer composite materials based on chemical copper plating, comprising the following steps: Step 1: The W powder is subjected to lamellar treatment by high-energy ball milling or plasma ball milling to obtain flaky W powder with an average particle size of 10μm~50μm. The ball-to-material ratio is 10~50:1, the ball mill speed is 300r / min~1200r / min, and the ball milling time is 3h~12h. Step 2: Prepare the copper plating solution; The specific process is as follows: Anhydrous copper sulfate, potassium sodium tartrate, and deionized water are mixed, and then 2,2'-bipyridine is added to obtain a mixed solution. The mixed solution is heated to 40℃~60℃, and then NaOH solution is added to adjust the pH value of the mixed solution to 10~13. Finally, glyoxylic acid solution is added to obtain a copper plating solution. The molar ratio of anhydrous copper sulfate, potassium sodium tartrate, and glyoxylic acid in each liter of deionized water is 1:1~2:0.5~1.5. The mass ratio of 2,2'-bipyridine to deionized water is 1:50000; Step 3: Add the flake W powder obtained in Step 1 to the copper plating solution obtained in Step 2 and react for 1 min to 10 min. After the reaction, filter and wash repeatedly with deionized water, and then freeze dry to obtain W-Cu composite powder with Cu-coated flake W powder. Step 4: The W-Cu composite powder with Cu-coated flake W powder obtained in Step 3 is sintered by vacuum hot pressing to obtain W-Cu micro-layer composite material. The process parameters for vacuum hot pressing sintering are as follows: vacuum degree below 10. -3 Pa, temperature is 850℃~1050℃, holding time is 20min~50min, pressing pressure is 20MPa~100MPa.

[0019] This invention relates to a method for preparing W-Cu micro-layered composite materials using electroless copper plating. By controlling the spatial distribution of the copper and tungsten phases, it achieves synergistic optimization of thermal conductivity and thermal expansion properties. Specifically, the copper phase forms continuous or semi-continuous thermal conduction paths within the layered structure, which helps reduce interfacial thermal resistance and improve overall thermal conductivity. The tungsten phase, with its low thermal expansion characteristics, constrains the copper phase, suppressing its expansion during temperature changes and thus reducing the overall coefficient of thermal expansion of the material. Simultaneously, the layered structure allows the material to exhibit differentiated thermal conductivity and thermal expansion responses in different directions, effectively leveraging the respective advantages of copper and tungsten to achieve synergistic optimization of thermal conductivity and thermal expansion properties. Furthermore, the micro-layered structure can disperse stress and inhibit crack propagation during stress, improving the overall mechanical properties and structural stability of the material.

[0020] Example 1 Step 1: The W powder is subjected to lamellarization treatment by planetary high-energy ball milling to obtain lamellar W powder with an average particle size of 21 μm. The ball-to-material ratio was 10:1, the ball mill speed was 300 r / min, the ball milling time was 12 h, and 3 wt.% anhydrous ethanol was added to the grinding balls and W powder before ball milling and stirred. Step 2: Prepare the copper plating solution; The specific process is as follows: Anhydrous copper sulfate, potassium sodium tartrate, and deionized water are mixed, and then 2,2'-bipyridine is added to obtain a mixed solution. The mixed solution is heated to 40°C, and then NaOH solution is added to adjust the pH value of the mixed solution to 10. Finally, glyoxylic acid solution is added to obtain a copper plating solution. The molar ratio of anhydrous copper sulfate, potassium sodium tartrate, and glyoxylic acid in each liter of deionized water is 1:1:0.5. The mass ratio of 2,2'-bipyridine to deionized water is 1:50000; Step 3: Add the flake W powder obtained in Step 1 to the copper plating solution obtained in Step 2 and react for 1 minute. After the reaction, filter and wash repeatedly with deionized water, and then freeze dry to obtain W-Cu composite powder with Cu-coated flake W powder. Step 4: Pour the W-Cu composite powder with Cu-coated flake W powder obtained in Step 3 into the mold in batches. After each addition of the W-Cu composite powder with Cu-coated flake W powder, tap the outside of the mold twice to ensure that the W-Cu composite powder with Cu-coated flake W powder is horizontally oriented. Then, perform self-assembly by vacuum hot pressing sintering. After the heat preservation is completed, stop the pressurization and then cool with the furnace to obtain W-Cu micro-layer composite material. The process parameters for vacuum hot pressing sintering are as follows: vacuum degree below 10. -3 The temperature was 850℃, the holding time was 20min, and the pressing pressure was 20MPa to ensure the density of the sintered sample.

[0021] Example 2 Step 1: The W powder is subjected to lamellarization treatment by planetary high-energy ball milling to obtain lamellar W powder with an average particle size of 21 μm. The ball-to-material ratio was 30:1, the ball mill speed was 600 r / min, the ball milling time was 6 h, and 3 wt.% anhydrous ethanol was added to the grinding balls and W powder before ball milling and stirred. Step 2: Prepare the copper plating solution; The specific process is as follows: Anhydrous copper sulfate, potassium sodium tartrate, and deionized water are mixed, and then 2,2'-bipyridine is added to obtain a mixed solution. The mixed solution is heated to 50°C, and then NaOH solution is added to adjust the pH value of the mixed solution to 1. Finally, glyoxylic acid solution is added to obtain a copper plating solution. The molar ratio of anhydrous copper sulfate, potassium sodium tartrate, and glyoxylic acid in each liter of deionized water is 1:1.5:1. The mass ratio of 2,2'-bipyridine to deionized water is 1:50000; Step 3: Add the flake W powder obtained in Step 1 to the copper plating solution obtained in Step 2 and react for 5 minutes. After the reaction, filter and wash repeatedly with deionized water, and then freeze dry to obtain W-Cu composite powder with Cu-coated flake W powder. Step 4: Pour the W-Cu composite powder with Cu-coated flake W powder obtained in Step 3 into the mold in batches. After each addition of the W-Cu composite powder with Cu-coated flake W powder, tap the outside of the mold twice to ensure that the W-Cu composite powder with Cu-coated flake W powder is horizontally oriented. Then, perform self-assembly by vacuum hot pressing sintering. After the heat preservation is completed, stop the pressurization and then cool with the furnace to obtain W-Cu micro-layer composite material. The process parameters for vacuum hot pressing sintering are as follows: vacuum degree below 10. -3 The temperature was 950℃, the holding time was 30min, and the pressing pressure was 60MPa to ensure the density of the sintered sample.

[0022] Example 3 Step 1: The W powder is subjected to lamellarization treatment by planetary high-energy ball milling to obtain lamellar W powder with an average particle size of 21 μm. The ball-to-material ratio was 50:1, the ball mill speed was 1200 r / min, the ball milling time was 3 h, and 3 wt.% anhydrous ethanol was added to the grinding balls and W powder before ball milling and stirred. Step 2: Prepare the copper plating solution; The specific process is as follows: Anhydrous copper sulfate, potassium sodium tartrate, and deionized water are mixed, and then 2,2'-bipyridine is added to obtain a mixed solution. The mixed solution is heated to 60°C, and then NaOH solution is added to adjust the pH value of the mixed solution to 13. Finally, glyoxylic acid solution is added to obtain a copper plating solution. The molar ratio of anhydrous copper sulfate, potassium sodium tartrate, and glyoxylic acid in each liter of deionized water is 1:2:1.5. The mass ratio of 2,2'-bipyridine to deionized water is 1:50000; Step 3: Add the flake W powder obtained in Step 1 to the copper plating solution obtained in Step 2 and react for 10 min. After the reaction, filter and wash repeatedly with deionized water, and then freeze dry to obtain W-Cu composite powder with Cu-coated flake W powder. Step 4: Pour the W-Cu composite powder with Cu-coated flake W powder obtained in Step 3 into the mold in batches. After each addition of the W-Cu composite powder with Cu-coated flake W powder, tap the outside of the mold twice to ensure that the W-Cu composite powder with Cu-coated flake W powder is horizontally oriented. Then, perform self-assembly by vacuum hot pressing sintering. After the heat preservation is completed, stop the pressurization and then cool with the furnace to obtain W-Cu micro-layer composite material. The process parameters for vacuum hot pressing sintering are as follows: vacuum degree below 10. -3 The temperature was 1050℃, the holding time was 50min, and the pressing pressure was 100MPa to ensure the density of the sintered sample.

[0023] Example 4 Step 1: The W powder is subjected to lamellarization treatment by planetary high-energy ball milling to obtain lamellar W powder with an average particle size of 21 μm. The ball-to-material ratio was 20:1, the ball mill speed was 400 r / min, the ball milling time was 8 h, and 3 wt.% anhydrous ethanol was added to the grinding balls and W powder before ball milling and stirred. Step 2: Prepare the copper plating solution; The specific process is as follows: Anhydrous copper sulfate, potassium sodium tartrate, and deionized water are mixed, and then 2,2'-bipyridine is added to obtain a mixed solution. The mixed solution is heated to 60°C, and then NaOH solution is added to adjust the pH value of the mixed solution to 12. Finally, glyoxylic acid solution is added to obtain a copper plating solution. The molar ratio of anhydrous copper sulfate, potassium sodium tartrate, and glyoxylic acid in each liter of deionized water is 1:1.4:1. The mass ratio of 2,2'-bipyridine to deionized water is 1:50000; Step 3: Add the flake W powder obtained in Step 1 to the copper plating solution obtained in Step 2 and react for 8 minutes. After the reaction, filter and wash repeatedly with deionized water, and then freeze dry to obtain W-Cu composite powder with Cu-coated flake W powder. Step 4: Pour the W-Cu composite powder with Cu-coated flake W powder obtained in Step 3 into the mold in batches. After each addition of the W-Cu composite powder with Cu-coated flake W powder, tap the outside of the mold twice to ensure that the W-Cu composite powder with Cu-coated flake W powder is horizontally oriented. Then, perform self-assembly by vacuum hot pressing sintering. After the heat preservation is completed, stop the pressurization and then cool with the furnace to obtain W-Cu micro-layer composite material. The process parameters for vacuum hot pressing sintering are as follows: vacuum degree below 10. -3 The temperature was 1000℃, the holding time was 40min, and the pressing pressure was 40MPa to ensure the density of the sintered sample.

[0024] like Figure 1As shown, W-Cu composite powder, prepared by chemical plating, with Cu coating flake W powder, is combined with W by hot pressing and sintering to obtain a W-Cu composite material with typical micro-layered structure characteristics (i.e., the W-Cu micro-layered composite material obtained in this embodiment). The compressive and flexural strength of the obtained W-Cu micro-layered composite material were tested. The results showed that the compressive and flexural strengths perpendicular to the flake direction reached 1491 MPa and 640 MPa, respectively, while the compressive and flexural strengths parallel to the flake direction reached 939 MPa and 752 MPa, respectively. Under the combined action of the micro-layered structure, thermal load, and mechanical constraint, the interlayer interface within the material can effectively induce the dispersion and release of thermal stress, and promote multiple deflections and passivation of microcracks within the interlayers, resulting in a more tortuous and complex crack propagation path along the interlayer interface. This interface regulation mechanism significantly increases the crack propagation path length and energy dissipation process, thereby effectively alleviating thermal stress concentration and inhibiting the rapid penetration and propagation of cracks within the material. As a result, the material can withstand more complex thermal cycling and power impact conditions during the service of electronic packaging heat sinks, and its thermal fatigue resistance and long-term service reliability are significantly improved.

[0025] Example 5 Step 1: The W powder is subjected to lamellarization treatment by planetary high-energy ball milling to obtain lamellar W powder with an average particle size of 10 μm. The ball-to-material ratio was 40:1, the ball mill speed was 400 r / min, the ball milling time was 8 h, and 3 wt.% anhydrous ethanol was added to the grinding balls and W powder before ball milling and stirred. Step 2: Prepare the copper plating solution; The specific process is as follows: Anhydrous copper sulfate, potassium sodium tartrate, and deionized water are mixed, and then 2,2'-bipyridine is added to obtain a mixed solution. The mixed solution is heated to 60°C, and then NaOH solution is added to adjust the pH value of the mixed solution to 12. Finally, glyoxylic acid solution is added to obtain a copper plating solution. The molar ratio of anhydrous copper sulfate, potassium sodium tartrate, and glyoxylic acid in each liter of deionized water is 1:1.5:1.5. The mass ratio of 2,2'-bipyridine to deionized water is 1:50000; Step 3: Add the flake W powder obtained in Step 1 to the copper plating solution obtained in Step 2 and react for 8 minutes. After the reaction, filter and wash repeatedly with deionized water, and then freeze dry to obtain W-Cu composite powder with Cu-coated flake W powder. Step 4: Pour the W-Cu composite powder with Cu-coated flake W powder obtained in Step 3 into the mold in batches. After each addition of the W-Cu composite powder with Cu-coated flake W powder, tap the outside of the mold twice to ensure that the W-Cu composite powder with Cu-coated flake W powder is horizontally oriented. Then, perform self-assembly by vacuum hot pressing sintering. After the heat preservation is completed, stop the pressurization and then cool with the furnace to obtain W-Cu micro-layer composite material. The process parameters for vacuum hot pressing sintering are as follows: vacuum degree below 10. -3 The temperature was 1000℃, the holding time was 40min, and the pressing pressure was 40MPa to ensure the density of the sintered sample.

[0026] Example 6 Step 1: The W powder is subjected to lamellarization treatment by planetary high-energy ball milling to obtain lamellar W powder with an average particle size of 50 μm. The ball-to-material ratio was 20:1, the ball mill speed was 400 r / min, the ball milling time was 8 h, and 3 wt.% anhydrous ethanol was added to the grinding balls and W powder before ball milling and stirred. Step 2: Prepare the copper plating solution; The specific process is as follows: Anhydrous copper sulfate, potassium sodium tartrate, and deionized water are mixed, and then 2,2'-bipyridine is added to obtain a mixed solution. The mixed solution is heated to 60°C, and then NaOH solution is added to adjust the pH value of the mixed solution to 12. Finally, glyoxylic acid solution is added to obtain a copper plating solution. The molar ratio of anhydrous copper sulfate, potassium sodium tartrate, and glyoxylic acid in each liter of deionized water is 1:1:1.5. The mass ratio of 2,2'-bipyridine to deionized water is 1:50000; Step 3: Add the flake W powder obtained in Step 1 to the copper plating solution obtained in Step 2 and react for 8 minutes. After the reaction, filter and wash repeatedly with deionized water, and then freeze dry to obtain W-Cu composite powder with Cu-coated flake W powder. Step 4: Pour the W-Cu composite powder with Cu-coated flake W powder obtained in Step 3 into the mold in batches. After each addition of the W-Cu composite powder with Cu-coated flake W powder, tap the outside of the mold twice to ensure that the W-Cu composite powder with Cu-coated flake W powder is horizontally oriented. Then, perform self-assembly by vacuum hot pressing sintering. After the heat preservation is completed, stop the pressurization and then cool with the furnace to obtain W-Cu micro-layer composite material. The process parameters for vacuum hot pressing sintering are as follows: vacuum degree below 10. -3 The temperature was 1000℃, the holding time was 40min, and the pressing pressure was 40MPa to ensure the density of the sintered sample.

Claims

1. A method for preparing W-Cu micro-layered composite materials based on chemical copper plating, characterized in that, The steps are as follows: Step 1: The W powder is subjected to a lamellarization process by ball milling to obtain flake-shaped W powder; Step 2: Prepare the copper plating solution; Step 3: Add the flake W powder obtained in Step 1 to the copper plating solution obtained in Step 2 for reaction. After the reaction, repeatedly filter and wash with deionized water, and then freeze dry to obtain W-Cu composite powder with Cu-coated flake W powder. Step 4: The W-Cu composite powder with Cu-coated flake W powder obtained in Step 3 is sintered by vacuum hot pressing to obtain W-Cu micro-layer composite material.

2. The method for preparing W-Cu micro-layered composite material based on electroless copper plating according to claim 1, characterized in that, In step 1, the ball milling is carried out using high-energy ball milling or plasma ball milling, with a ball-to-material ratio of 10~50:1, a ball milling speed of 300r / min~1200r / min, and a ball milling time of 3h~12h.

3. The method for preparing W-Cu micro-layered composite material based on chemical copper plating according to claim 1, characterized in that, In step 1, the average particle size of the flake W powder is 10μm~50μm.

4. The method for preparing W-Cu micro-layered composite material based on electroless copper plating according to claim 1, characterized in that, Step 2 is as follows: Mix anhydrous copper sulfate, potassium sodium tartrate and deionized water, then add 2,2'-bipyridine to obtain a mixed solution. Heat the mixed solution to a set temperature, add NaOH solution to adjust the pH value of the mixed solution to 10~13, and then add glyoxylic acid solution to obtain a copper plating solution.

5. The method for preparing W-Cu micro-layered composite material based on chemical copper plating according to claim 4, characterized in that, In step 2, the molar ratio of anhydrous copper sulfate, potassium sodium tartrate, and glyoxylic acid per liter of deionized water is 1:1~2:0.5~1.5; The mass ratio of 2,2'-bipyridine to deionized water is 1:50000.

6. The method for preparing W-Cu micro-layered composite material based on chemical copper plating according to claim 4, characterized in that, In step 2, the temperature is set to 40℃~60℃.

7. The method for preparing W-Cu micro-layered composite material based on electroless copper plating according to claim 1, characterized in that, In step 3, the reaction time is 1 min to 10 min.

8. The method for preparing W-Cu micro-layered composite material based on electroless copper plating according to claim 1, characterized in that, In step 4, the process parameters for vacuum hot pressing sintering are: vacuum degree below 10. -3 Pa, temperature is 850℃~1050℃, holding time is 20min~50min, pressing pressure is 20MPa~100MPa.

9. A W-Cu micro-layer composite material based on electroless copper plating, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 8.

Images