Disclosure of Invention
Aiming at the defects of the prior art, the application provides the high-strength heat-conducting semiconductor packaging solder alloy and the preparation method thereof, and the high-strength heat-conducting semiconductor packaging solder alloy has high oxidation resistance, low slag yield, mechanical property and heat conducting property, and the addition of the copper-nickel-graphene intermediate alloy not only improves the overall hardness and wear resistance of the material, but also obviously enhances the heat conducting property, is particularly suitable for being applied to packaging links of high-density integrated circuits in high-performance electronic equipment, and solves the problems of low stability and heat dissipation efficiency of the traditional solder material at high temperature. The trace amount of phosphorus and germanium are added, so that no obvious influence is caused on the melting temperature of the solder alloy, but the slag yield is reduced, and the oxidation resistance of the solder alloy is improved. In addition, the preparation method is simple, high in production efficiency and low in cost.
The application provides a high-strength heat-conducting semiconductor packaging tin alloy, which adopts the following technical scheme that the high-strength heat-conducting semiconductor packaging tin alloy comprises, by mass, 97-98 parts of tin, 0.4-0.6 part of copper, 0.6-0.8 part of silver, 0.008-0.011 part of germanium, 0.01-0.018 part of phosphorus and 0.8-1.2 parts of copper-nickel-graphene intermediate alloy.
By adopting the technical scheme, the high-strength heat-conducting soldering tin alloy for semiconductor packaging contains a plurality of elements, and each element plays a unique role in the alloy, namely, tin is used as a main component, and provides good electric conductivity and lower melting point, so that the tin is easy to melt and forms firm connection after cooling. The small amount of copper increases the hardness and wear resistance of the alloy, and simultaneously improves the heat conducting property. The addition of silver further enhances the electrical and thermal conductivity of the alloy while improving the corrosion resistance. Germanium, although the germanium content is very small, it helps to lower the melting temperature of the solder alloy while improving its oxidation resistance. Phosphorus, a trace amount of phosphorus also contributes to the improvement of oxidation resistance and the reduction of slag production in the welding process. The composite intermediate alloy obviously improves the overall hardness, wear resistance and heat conduction performance of the soldering tin alloy, is particularly suitable for packaging high-density integrated circuits, and solves the problems of insufficient stability and heat dissipation efficiency of the traditional soldering tin material at high temperature. The addition of germanium and phosphorus effectively improves the oxidation resistance of the alloy. The slag yield is low, and trace germanium and phosphorus reduce the slag yield in the welding process. The mechanical property and the heat conduction property of the copper, silver and copper-nickel-graphene intermediate alloy jointly improve the hardness, the wear resistance and the heat conduction property of the alloy. The preparation process of the copper-nickel-graphene intermediate alloy ensures the uniform dispersion of graphene, further optimizes the microstructure of the alloy and improves the overall performance of the alloy. In a word, the solder alloy realizes excellent mechanical property, heat conduction property and oxidation resistance through carefully designed component proportion and preparation process, and is very suitable for high-density integrated circuit packaging in high-performance electronic equipment.
Preferably, the mass ratio of the germanium to the phosphorus is 1:1.5.
By adopting the technical scheme, the mass part ratio of germanium to phosphorus is 1:1.5, and the design of the proportion is to reduce the production cost while ensuring that the soldering tin alloy has high oxidation resistance, low slag yield, excellent mechanical property and heat conduction property. Germanium is a semiconductor element, and the addition of germanium can improve the thermal stability and oxidation resistance of the solder alloy. Meanwhile, germanium can also improve the electrical conductivity and thermal conductivity of the soldering tin alloy, so that the application performance of the soldering tin alloy in high-density integrated circuit packaging is improved. Phosphorus is a nonmetallic element, and the addition of phosphorus can reduce the melting point of the soldering tin alloy, improve the fluidity and spreadability of the soldering tin alloy, and further reduce the slag yield. In addition, phosphorus can also improve the corrosion resistance and oxidation resistance of the solder alloy. By setting the mass part ratio of germanium to phosphorus to 1:1.5, the production cost can be reduced while the excellent performance of the soldering tin alloy is ensured. Meanwhile, the design of the proportion can also lead germanium and phosphorus to form stable compounds in the solder alloy, thereby further improving the performance of the solder alloy.
Preferably, the copper-nickel-graphene intermediate alloy comprises, by mass, 15 parts of graphene oxide, 850 parts of ethanol, 15.3 parts of nickel acetate, 60.2 parts of pure copper powder, 4 parts of dopamine and 150 parts of tris (hydroxymethyl) aminomethane hydrochloride solution with the pH of 7.0.
Preferably, the preparation method of the copper-nickel-graphene intermediate alloy comprises the following steps:
s41, mixing graphene oxide, dopamine and ethanol according to parts by weight to prepare a graphene oxide dispersion;
s42, respectively adding nickel acetate, pure copper powder and a tris hydrochloride solution with the pH value of 7.0 into graphene oxide dispersion, stirring uniformly, heating to 50-55 ℃ for reacting for 5-8 hours, concentrating to dryness, and collecting a solid phase, and S43, calcining the solid phase in a reducing atmosphere at 1170-1190 ℃ for 3-4 hours, and cooling to room temperature to obtain the copper-nickel-graphene intermediate alloy.
According to the technical scheme, in the preparation process of the copper-nickel-graphene intermediate alloy, rich oxygen-containing functional groups are arranged on the surface of graphene oxide, and the dopamine is used for carrying out nitrogen modification on the graphene oxide, so that nickel elements and pure copper powder are fully dispersed through the nitrogen-containing groups and the oxygen-containing functional groups, and the intermediate alloy with smaller granularity and more uniform distribution is prepared, so that the dispersibility of the components in the finally prepared solder alloy is further improved, the uniform dispersion, more stable structure and finer grains of the graphene are realized, and the prepared solder alloy shows excellent mechanical property and heat dissipation performance. By adding the copper-nickel-graphene intermediate alloy, the overall hardness and wear resistance of the solder alloy can be remarkably improved. This is particularly important in the packaging of high density integrated circuits in high performance electronic devices, where materials with higher mechanical strength and wear resistance are required. Graphene is used as a material with high thermal conductivity, and the addition of the graphene can obviously enhance the thermal conductivity of the solder alloy. The solder material has important significance in solving the problem of low heat dissipation efficiency of the traditional solder material at high temperature, and is beneficial to improving the stability and reliability of electronic equipment. Through the oxygen-containing functional groups rich in the surface of graphene oxide and the nitrogen modification of dopamine, the nickel element and the pure copper powder can be fully dispersed, so that the intermediate alloy with smaller granularity and more uniform distribution can be prepared. The method is favorable for further improving the dispersibility of the graphene in the finally prepared solder alloy and avoiding the occurrence of agglomeration. The solder alloy obtained by the uniform dispersion and the more stable structure preparation of the graphene has excellent mechanical property and heat dissipation performance. This is of great importance for improving the application properties of the solder alloy.
Preferably, in step S43, the reducing gas is composed of argon and hydrogen, wherein the volume percentage of the argon in the reducing gas is 75-80%, and the balance is hydrogen, and the flow rate of the reducing gas is 4.5L/min.
Preferably, the graphene oxide has a sheet diameter of 0.5-2 μm and a thickness of 0.8-1.5 nm, and the pure copper powder has a purity of 99.99% and a particle diameter of 1-2 μm.
In a second aspect, the application provides a method for preparing a solder alloy for high-strength heat-conducting semiconductor packaging, which adopts the following technical scheme:
the application also provides a preparation method of the solder alloy for high-strength heat-conducting semiconductor packaging, which comprises the following steps of:
S71, uniformly mixing tin, copper, silver and germanium raw materials in proportion according to parts by weight, preheating to 150-200 ℃, and removing a surface oxide layer to obtain a mixture;
S72, sending the mixture into an induction furnace under the argon atmosphere, heating to fully melt the mixture into a liquid state to obtain alloy melt A, and sequentially adding phosphorus and copper-nickel-graphene intermediate alloy into the alloy melt A, heating, stirring and fully melting the intermediate alloy into a liquid state to obtain alloy melt B;
and S74, casting the alloy melt B into a die preheated to 100 ℃ for cooling and molding, then carrying out first vacuum annealing heat treatment and second vacuum annealing heat treatment, and finally rapidly cooling to room temperature to obtain the high-strength heat-conducting solder alloy for semiconductor packaging.
Preferably, in step S72, the temperature is raised to 360-400 ℃.
Preferably, in the step S73, the temperature is raised to 440-450 ℃ by heating, the stirring speed is 400-500 r/min, and the time is 15-20 minutes.
Preferably, in the step S74, the temperature of the first vacuum annealing heat treatment is 250-280 ℃, the time is 1h-2h, the vacuum degree is 1kPa, the temperature of the second vacuum annealing heat treatment is 220-240 ℃, the time is 1h-2h, and the vacuum degree is 1kPa.
By adopting the technical scheme, the first and second vacuum annealing heat treatments play a vital role in the preparation process of the solder alloy for the high-strength heat-conducting semiconductor packaging, and are specifically characterized in that 1, the recrystallization of crystal grains is promoted, namely, the temperature of the first vacuum annealing heat treatment is higher, which is helpful for eliminating residual stress generated in the casting process and rapid cooling of the alloy, and promoting the recrystallization of the crystal grains. Through grain recrystallization, the grain fine density and uniformity of the solder can be improved, so that the mechanical property and corrosion resistance of the solder alloy are improved. The temperature of the second vacuum annealing heat treatment is relatively low, which helps to further optimize the microstructure of the alloy, allowing for a more uniform distribution of the various elements. The uniform element distribution can improve the uniformity and consistency of the components of the solder alloy, thereby improving the welding performance, oxidation resistance and heat dissipation performance of the solder alloy. 3. The mechanical property and corrosion resistance are improved, namely the microstructure and component distribution of the soldering tin alloy can be gradually adjusted and optimized through two times of vacuum annealing heat treatment at different temperatures, so that the overall mechanical property and corrosion resistance of the soldering tin alloy are improved. This is particularly important in the packaging of high density integrated circuits in high performance electronic devices, where materials with higher mechanical strength and corrosion resistance are required. 4. The welding performance and the oxidation resistance are improved, namely, the control of temperature and time parameters in the vacuum annealing heat treatment process can lead various elements in the alloy to be more uniformly distributed, thereby improving the welding performance and the oxidation resistance of the soldering tin alloy. This is of great importance for improving the application properties of the solder alloy. 5. The production efficiency is improved, the cost is reduced, and the production efficiency is improved while the performance of the soldering tin alloy is ensured through a reasonable vacuum annealing treatment process. In summary, the first and second vacuum annealing heat treatments in step S74 play a critical role in the preparation process of the solder alloy for high-strength heat-conductive semiconductor packaging, and they cooperate to improve the mechanical properties, corrosion resistance, soldering properties and oxidation resistance of the solder alloy, so as to meet the requirements of high-density integrated circuit packaging in high-performance electronic equipment.
In summary, the beneficial technical effects of the application are as follows:
1. The oxidation resistance of the soldering tin alloy is obviously improved by adding trace phosphorus and germanium. Although the melting temperature of the trace elements is not obviously changed, the generation of oxides in the welding process is effectively reduced, so that the slag yield is reduced.
2. And the low slag yield is that due to the addition of phosphorus and germanium, the oxidation slag generated in the melting and welding process of the soldering tin alloy is obviously reduced, so that the welding quality and efficiency are improved, and the complexity of the subsequent cleaning work is reduced.
3. The excellent mechanical properties are that the overall hardness and the wear resistance of the solder alloy are obviously enhanced by adding the copper-nickel-graphene intermediate alloy. The intermediate alloy realizes the uniform dispersion of nickel element and pure copper powder through the nitrogen modified graphene oxide, thereby improving the mechanical property of the soldering tin alloy.
4. The introduction of the graphene obviously improves the heat conduction capability of the soldering tin alloy, so that the soldering tin alloy is particularly suitable for packaging high-density integrated circuits in high-performance electronic equipment, and the problem that the heat dissipation efficiency of the traditional soldering tin material is low in a high-temperature environment is solved.
5. The preparation method is simple and efficient, and comprises the steps of preheating, removing an oxide layer, smelting, adding trace elements, casting, performing vacuum annealing heat treatment twice and the like. The whole process is easy to operate, the production efficiency is high, and the cost is low.
6. And the uniform microstructure is that residual stress in the alloy is eliminated through strict vacuum annealing heat treatment, and crystal grains are refined and uniformly distributed, so that the mechanical property and corrosion resistance of the soldering tin alloy are further improved.
Detailed Description
Embodiments of the present application will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only for illustrating the present application and should not be construed as limiting the scope of the present application. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used were not manufacturer-identified and were all commercially available conventional products with 99.9% purity for all metals and 99.95% purity for phosphorus.
In the following examples and preparations, 1 part represents 100g.
Preparation example 1 preparation of copper-Nickel-graphene intermediate alloy
The copper-nickel-graphene intermediate alloy comprises, by mass, 15 parts of graphene oxide, 850 parts of ethanol, 15.3 parts of nickel acetate, 60.2 parts of pure copper powder, 4 parts of dopamine and 150 parts of tris (hydroxymethyl) aminomethane hydrochloride solution with the pH of 7.0, wherein the graphene oxide has the sheet diameter of 0.5-2 mu m and the thickness of 0.8-1.5 nm, the pure copper powder has the purity of 99.99% and the particle diameter of 1-2 mu m;
The preparation method of the copper-nickel-graphene intermediate alloy comprises the following steps:
s41, mixing graphene oxide, dopamine and ethanol according to parts by weight to prepare a graphene oxide dispersion;
s42, respectively adding nickel acetate, pure copper powder and a tris hydrochloride solution with the pH of 7.0 into the graphene oxide dispersion, uniformly stirring, heating to 50 ℃ for reacting for 8 hours, concentrating to dryness, and collecting a solid phase;
S43, calcining the solid phase in a reducing atmosphere for 4 hours at 1170 ℃, and cooling to room temperature to obtain the copper-nickel-graphene intermediate alloy, wherein the reducing gas consists of argon and hydrogen, the volume percentage of the argon in the reducing gas is 75%, the balance is hydrogen, and the flow rate of the reducing gas is 4.5L/min.
Preparation example 2 preparation of copper-nickel-graphene intermediate alloy
The copper-nickel-graphene intermediate alloy comprises, by mass, 15 parts of graphene oxide, 850 parts of ethanol, 15.3 parts of nickel acetate, 60.2 parts of pure copper powder, 4 parts of dopamine and 150 parts of tris (hydroxymethyl) aminomethane hydrochloride solution with the pH of 7.0, wherein the graphene oxide has the sheet diameter of 0.5-2 mu m and the thickness of 0.8-1.5 nm, the pure copper powder has the purity of 99.99% and the particle diameter of 1-2 mu m;
The preparation method of the copper-nickel-graphene intermediate alloy comprises the following steps:
s41, mixing graphene oxide, dopamine and ethanol according to parts by weight to prepare a graphene oxide dispersion;
S42, respectively adding nickel acetate, pure copper powder and a tris hydrochloride solution with the pH of 7.0 into the graphene oxide dispersion, uniformly stirring, heating to 55 ℃ for reacting for 5 hours, concentrating to dryness, and collecting a solid phase;
s43, calcining the solid phase in a reducing atmosphere at 1190 ℃ for 3 hours, and cooling to room temperature to obtain the copper-nickel-graphene intermediate alloy, wherein the reducing gas consists of argon and hydrogen, the volume percentage of the argon in the reducing gas is 80%, the balance is hydrogen, and the flow rate of the reducing gas is 4.5L/min.
Preparation example 3 preparation of copper-Nickel-graphene intermediate alloy
The copper-nickel-graphene intermediate alloy comprises, by mass, 15 parts of graphene oxide, 850 parts of ethanol, 15.3 parts of nickel acetate, 60.2 parts of pure copper powder, 4 parts of dopamine and 150 parts of tris (hydroxymethyl) aminomethane hydrochloride solution with the pH of 7.0, wherein the graphene oxide has the sheet diameter of 0.5-2 mu m and the thickness of 0.8-1.5 nm, the pure copper powder has the purity of 99.99% and the particle diameter of 1-2 mu m;
The preparation method of the copper-nickel-graphene intermediate alloy comprises the following steps:
s41, mixing graphene oxide, dopamine and ethanol according to parts by weight to prepare a graphene oxide dispersion;
S42, respectively adding nickel acetate, pure copper powder and a tris hydrochloride solution with the pH of 7.0 into the graphene oxide dispersion, uniformly stirring, heating to 53 ℃ for reaction for 7 hours, concentrating to dryness, and collecting a solid phase;
S43, calcining the solid phase in a reducing atmosphere at 1180 ℃ for 3.4 hours, and cooling to room temperature to obtain the copper-nickel-graphene intermediate alloy, wherein the reducing gas consists of argon and hydrogen, the volume percentage of the argon in the reducing gas is 78%, the balance is hydrogen, and the flow rate of the reducing gas is 4.5L/min.
Example 1
The solder alloy for the high-strength heat-conducting semiconductor packaging comprises, by mass, 97 parts of tin, 0.4 part of copper, 0.6 part of silver, 0.008 part of germanium, 0.01 part of phosphorus and 0.8 part of copper-nickel-graphene intermediate alloy, wherein the copper-nickel-graphene intermediate alloy is prepared from preparation example 1;
The preparation method of the solder alloy for high-strength heat-conducting semiconductor packaging comprises the following steps:
s71, uniformly mixing tin, copper, silver and germanium raw materials in proportion according to parts by weight, preheating to 150 ℃, and removing a surface oxide layer to obtain a mixture;
s72, sending the mixture into an induction furnace under the argon atmosphere, and heating to 360 ℃ to enable the mixture to be fully melted into a liquid state to obtain alloy melt A;
S73, sequentially adding phosphorus and copper-nickel-graphene intermediate alloy into the alloy melt A, heating to 440 ℃, and stirring for 20 minutes at the stirring speed of 400 rpm to fully melt the intermediate alloy into a liquid state to obtain alloy melt B;
And S74, casting the alloy melt B into a mould preheated to 100 ℃ for cooling and molding, and then carrying out first vacuum annealing heat treatment and second vacuum annealing heat treatment, and finally cooling to room temperature quickly to obtain the solder alloy for the high-strength heat-conducting semiconductor packaging, wherein the temperature of the first vacuum annealing heat treatment is 250 ℃, the time is 2h, the vacuum degree is 1kPa, and the temperature of the second vacuum annealing heat treatment is 220 ℃, the time is 2h, and the vacuum degree is 1kPa.
Example 2
The solder alloy for high-strength heat-conducting semiconductor packaging comprises, by mass, 98 parts of tin, 0.6 part of copper, 0.8 part of silver, 0.011 part of germanium, 0.018 part of phosphorus and 1.2 parts of copper-nickel-graphene intermediate alloy, wherein the copper-nickel-graphene intermediate alloy is prepared from preparation example 2;
The preparation method of the solder alloy for high-strength heat-conducting semiconductor packaging comprises the following steps:
S71, uniformly mixing tin, copper, silver and germanium raw materials in proportion according to parts by weight, preheating to 200 ℃, and removing a surface oxide layer to obtain a mixture;
S72, sending the mixture into an induction furnace under the argon atmosphere, and heating to 400 ℃ to enable the mixture to be fully melted into a liquid state to obtain alloy melt A;
s73, sequentially adding phosphorus and copper-nickel-graphene intermediate alloy into the alloy melt A, heating to 450 ℃, and stirring for 15 minutes at the stirring speed of 500 revolutions per minute to fully melt the intermediate alloy into a liquid state to obtain alloy melt B;
And S74, casting the alloy melt B into a mould preheated to 100 ℃ for cooling and molding, then carrying out first vacuum annealing heat treatment and second vacuum annealing heat treatment, and finally rapidly cooling to room temperature to obtain the solder alloy for high-strength heat-conducting semiconductor packaging, wherein the temperature of the first vacuum annealing heat treatment is 280 ℃, the time is 1h, the vacuum degree is 1kPa, and the temperature of the second vacuum annealing heat treatment is 240 ℃, the time is 1h, and the vacuum degree is 1kPa.
Example 3
The solder alloy for high-strength heat-conducting semiconductor packaging comprises, by mass, 97.5 parts of tin, 0.5 part of copper, 0.7 part of silver, 0.009 part of germanium, 0.012 part of phosphorus and 1 part of copper-nickel-graphene intermediate alloy, wherein the copper-nickel-graphene intermediate alloy is prepared from preparation example 3;
The preparation method of the solder alloy for high-strength heat-conducting semiconductor packaging comprises the following steps:
S71, uniformly mixing tin, copper, silver and germanium raw materials in proportion according to parts by weight, preheating to 180 ℃, and removing a surface oxide layer to obtain a mixture;
S72, sending the mixture into an induction furnace under the argon atmosphere, and heating to 390 ℃ to enable the mixture to be fully melted into a liquid state to obtain alloy melt A;
s73, sequentially adding phosphorus and copper-nickel-graphene intermediate alloy into the alloy melt A, heating to 445 ℃, and stirring for 17 minutes at the stirring speed of 450 r/min to fully melt the intermediate alloy into a liquid state to obtain alloy melt B;
And S74, casting the alloy melt B into a mould preheated to 100 ℃ for cooling and molding, then carrying out first vacuum annealing heat treatment and second vacuum annealing heat treatment, and finally rapidly cooling to room temperature to obtain the solder alloy for high-strength heat-conducting semiconductor packaging, wherein the temperature of the first vacuum annealing heat treatment is 270 ℃, the time is 1.4h, the vacuum degree is 1kPa, and the temperature of the second vacuum annealing heat treatment is 230 ℃, the time is 1.4h, and the vacuum degree is 1kPa.
Example 4
The same as in example 3, except that germanium was 0.010 parts and phosphorus was 0.015 parts.
Comparative example 1
The same as in example 4, except that germanium was 0 part and phosphorus was 0 part.
Comparative example 2
The same as in example 4, except that the same amount of the mixture (graphene oxide, pure nickel powder having a particle size of 2 μm and pure copper powder having a particle size of 1 to 2 μm were mixed at a mass ratio of 15:3.7:60.2) was used instead of the copper-nickel-graphene intermediate alloy.
Comparative example 3
The same as in example 4, except that in step S74, only the first vacuum annealing heat treatment is performed, and no second vacuum annealing heat treatment is performed.
Comparative example 4
The same as in example 4, except that in step S74, there is no first vacuum annealing heat treatment and only a second vacuum annealing heat treatment.
Performance testing
The high-strength heat-conductive semiconductor packages prepared in example 1-example 4 and comparative example 1-comparative example 4 were sampled with a solder alloy and fabricated as a solder bar for performance testing;
melting point, namely measuring the melting temperature of the solder alloy by adopting a Diamondosc type differential scanning calorimeter, wherein the mass of a sample is about 10mg, the test temperature is 50-450 ℃, and the heating rate is 10 ℃ per minute;
Wetting angle is measured by IPC-TM-6502.4.45 test method;
The thermal conductivity is measured by DynaCool type thermal conductivity meter, the measuring temperature is 37-97 deg.C, the sample size is 2mm x 8mm;
The elongation test is carried out according to GB/11364-89 solder spreadability and joint adding property test method, and the higher the elongation is, the better the weldability of the solder alloy for high-strength heat-conducting semiconductor packaging is shown;
the oxidation resistance is tested by a static oxidation method, the temperature of a melting furnace is 270 ℃, the mass is 500g, slag is scraped every 60s, slag is taken every 5min, each group of tests is carried out 3 times, and the average value of 3 times is taken;
Corrosion resistance was determined using the IPC-TM-6502.6.15 test method.
Table 1 performance test
Analysis of the data in table 1, it can be seen that:
1) The solder alloy for high-strength heat-conducting semiconductor packaging prepared in the embodiment 1-4 has high oxidation resistance, low slag yield, mechanical property and heat-conducting property.
2) The comparative analysis of the performances of the high-strength heat-conducting semiconductor packaging solder alloy prepared in combination with the embodiment 4 and the embodiment 3 and the comparative embodiment 1 shows that the mass part ratio of germanium to phosphorus is 1:1.5, and the design of the ratio is to reduce the production cost while ensuring that the solder alloy has high oxidation resistance, low slag yield, excellent mechanical property and heat-conducting property. By setting the mass part ratio of germanium to phosphorus to 1:1.5, the production cost can be reduced while the excellent performance of the soldering tin alloy is ensured. Meanwhile, the design of the proportion can also lead germanium and phosphorus to form stable compounds in the solder alloy, thereby further improving the performance of the solder alloy.
3) According to the performance comparison analysis of the solder alloy for high-strength heat-conducting semiconductor packaging prepared by combining the embodiment 4 and the comparative embodiment 2, the surface of graphene oxide is utilized to have rich oxygen-containing functional groups in the preparation process of the copper-nickel-graphene intermediate alloy, and the dopamine is used for carrying out nitrogen modification on the graphene oxide, so that the nickel element and the pure copper powder are fully dispersed through the nitrogen-containing groups and the oxygen-containing functional groups, and the intermediate alloy with smaller granularity and more uniform distribution is prepared, so that the dispersibility of the components in the finally prepared solder alloy is further improved, the uniform dispersion, more stable structure and finer grains of the graphene are realized, and the prepared solder alloy shows excellent mechanical property and heat dissipation performance. By adding the copper-nickel-graphene intermediate alloy, the overall hardness and wear resistance of the solder alloy can be remarkably improved. This is particularly important in the packaging of high density integrated circuits in high performance electronic devices, where materials with higher mechanical strength and wear resistance are required. Graphene is used as a material with high thermal conductivity, and the addition of the graphene can obviously enhance the thermal conductivity of the solder alloy. The solder material has important significance in solving the problem of low heat dissipation efficiency of the traditional solder material at high temperature, and is beneficial to improving the stability and reliability of electronic equipment. Through the oxygen-containing functional groups rich in the surface of graphene oxide and the nitrogen modification of dopamine, the nickel element and the pure copper powder can be fully dispersed, so that the intermediate alloy with smaller granularity and more uniform distribution can be prepared. The method is favorable for further improving the dispersibility of the graphene in the finally prepared solder alloy and avoiding the occurrence of agglomeration. The solder alloy obtained by the uniform dispersion and the more stable structure preparation of the graphene has excellent mechanical property and heat dissipation performance. This is of great importance for improving the application properties of the solder alloy.
4) Performance comparative analysis of the solder alloy for high-strength, thermally conductive semiconductor packages prepared in combination with example 3 and comparative example 3-comparative example 4 shows that the first and second vacuum annealing heat treatments play a critical role in the preparation of the solder alloy for high-strength, thermally conductive semiconductor packages, in particular in 1. Promoting grain recrystallization, the temperature of the first vacuum annealing heat treatment is higher, which helps to eliminate residual stress generated by the alloy during casting and rapid cooling, promoting grain recrystallization. Through grain recrystallization, the grain fine density and uniformity of the solder can be improved, so that the mechanical property and corrosion resistance of the solder alloy are improved. The temperature of the second vacuum annealing heat treatment is relatively low, which helps to further optimize the microstructure of the alloy, allowing for a more uniform distribution of the various elements. The uniform element distribution can improve the uniformity and consistency of the components of the solder alloy, thereby improving the welding performance, oxidation resistance and heat dissipation performance of the solder alloy. 3. The mechanical property and corrosion resistance are improved, namely the microstructure and component distribution of the soldering tin alloy can be gradually adjusted and optimized through two times of vacuum annealing heat treatment at different temperatures, so that the overall mechanical property and corrosion resistance of the soldering tin alloy are improved. This is particularly important in the packaging of high density integrated circuits in high performance electronic devices, where materials with higher mechanical strength and corrosion resistance are required. 4. The welding performance and the oxidation resistance are improved, namely, the control of temperature and time parameters in the vacuum annealing heat treatment process can lead various elements in the alloy to be more uniformly distributed, thereby improving the welding performance and the oxidation resistance of the soldering tin alloy. This is of great importance for improving the application properties of the solder alloy. In summary, the first and second vacuum annealing heat treatments in step S74 play a critical role in the preparation process of the solder alloy for high-strength heat-conductive semiconductor packaging, and they cooperate to improve the mechanical properties, corrosion resistance, soldering properties and oxidation resistance of the solder alloy, so as to meet the requirements of high-density integrated circuit packaging in high-performance electronic equipment.
The above embodiments are only for illustrating the technical solution of the present application and not for limiting the same, and although the above embodiments specifically illustrate the present application, it should be understood by those skilled in the art that modifications and equivalents may be made to the specific embodiments of the present application without departing from the spirit and scope of the present application, and any modifications and equivalents are intended to be included in the scope of the present application.