Metal powder preparation device and preparation method

Abstract

The invention relates to the technical field of electronic welding material preparation, in particular to a metal powder preparation device and method. The metal powder preparation device comprises a pretreatment module and a preparation module. The pretreatment module comprises stirring and heating equipment and a grinding device communicated with an outlet of the stirring and heating equipment; the preparation module comprises a first container communicated with an outlet of the grinding device and an ultrasonic transducer arranged in the first container; an outlet of the grinding device points to the ultrasonic transducer; the ultrasonic transducer is disposed proximate an inner bottom of the first container. According to the metal powder preparation device and method, preparation of the superfine metal powder can be achieved, preparation of the powder with the specific specification and the superfine granularity can be achieved through the control technology, the granularity is controllable, meanwhile, the prepared metal powder has the beneficial effects of being low in oxygen content and high in yield, metal powder preparation is convenient and fast, equipment is small and convenient, and the production cost is low. And the method can be used for producing laboratory-grade superfine powder.

Description

Technical Field

[0001] The present application relates to the technical field of electronic welding material preparation, and in particular to a metal powder preparation device and preparation method. Background Art

[0002] Solder powder is a welding material used for interconnection of microelectronic packaging. Electronic terminal products are developing towards miniaturization, lightness, multi-function and integration, and the size of the corresponding chips is getting smaller and smaller, which puts higher requirements on chip design and manufacturing, and the internal solder joints are becoming more and more refined. Therefore, the electronic welding material solder powder is also required to be ultra-fine.

[0003] The particle size distribution of different types of solder powders are: Type 3 (25μm-45μm), Type 4 (20μm-38μm), Type 5 (15μm-25μm), Type 6 (5μm-15μm), Type 7 (2μm-11μm), Type 8 (2μm-8μm), Type 9 (1μm-5μm), etc. At present, the main preparation methods of solder powder are centrifugal atomization, ultrasonic atomization and gas atomization. The particle size of the raw powder prepared by these methods is normal. The distribution of powder particles is large, and the commonly used Type 3, Type 4, and Type 5 solder powders can be obtained through sorting. However, for Type 6, Type 7, Type 8, and Type 9 solder powders with finer particle sizes, the powder yield is low, and they are easy to agglomerate, and sorting is also relatively difficult. Therefore, it is difficult to prepare ultrafine solder powder materials of this type with existing mature preparation technologies. At the same time, the market demand for ultrafine solder powder continues to rise. Under this technical background, a breakthrough in the preparation technology of ultrafine solder powder is imminent. Summary of the invention

[0004] In view of the problems existing in the background technology, the present application provides a metal powder preparation device and a preparation method, which can realize the preparation of ultrafine metal powder.

[0005] According to one aspect of the present invention, there is provided a metal powder preparation device, comprising a pretreatment module and a preparation module; the pretreatment module comprises a stirring and heating device and a grinding device connected to the outlet of the stirring and heating device; the preparation module comprises a first container connected to the outlet of the grinding device and an ultrasonic transducer arranged in the first container; the outlet of the grinding device points to the ultrasonic transducer; the ultrasonic transducer is arranged close to the inner bottom of the first container.

[0006] By using the metal powder preparation device in the technical solution, first, according to the liquidus line T of the metal, a stirring and heating device is used to stir metal raw materials such as solder alloy and heat-resistant oil under high temperature conditions to obtain a uniform mixed metal solution, and then the mixed metal solution is fully ground and crushed using a grinding device. Thereafter, a high-frequency vibrating ultrasonic transducer is used to ultrasonicate the emulsion obtained by grinding, thereby obtaining a mixed solution of metal powder and heat-resistant oil. After the mixed solution is separated, metal powders such as ultrafine solder powder can be obtained, thereby realizing the preparation of ultrafine metal powder.

[0007] In some embodiments of the present invention, a second container is provided between the grinding device and the first container, the outlet of the grinding device is connected to the inlet of the second container, and the outlet of the second container points to the ultrasonic transducer.

[0008] In some embodiments of the present invention, the stirring and heating device includes: a third container; a stirring paddle, which is arranged in the third container; a first driver, which is connected to the stirring paddle; and a heating device, which is arranged on the third container.

[0009] Preferably, the bottom of the third container forms an outlet, and the outlet of the third container is provided with a valve.

[0010] In some embodiments of the present invention, the grinding device includes: a fourth container, the inner bottom of the fourth container forming a first grinding surface; a grinding disk, the grinding disk is arranged in the fourth container, and the side of the grinding disk facing the first grinding surface is formed with a second grinding surface arranged at an interval with the first grinding surface; a second drive, the second drive is connected to the grinding disk; the bottom wall of the fourth container is formed with a plurality of through holes, and the through holes connect the first grinding surface and the outside of the fourth container.

[0011] Preferably, the first grinding surface is a concave conical surface, and the second grinding surface is a convex conical surface matched with the first grinding surface.

[0012] Preferably, the concave conical surface has a cone angle of 0.5°-8°.

[0013] Preferably, a plurality of linear guide channels are formed on the first grinding surface and / or the second grinding surface, and the guide channels extend from the center of the first grinding surface and / or the second grinding surface to the outer circle.

[0014] Preferably, a plurality of scrapers are connected to the outer periphery of the grinding disc, and the scrapers are spaced apart from the inner bottom of the fourth container.

[0015] Preferably, the scraper protrudes 0.1 mm-1 mm toward the inner bottom of the fourth container compared to the second grinding surface toward the first grinding surface.

[0016] Preferably, evenly distributed grinding protrusions are respectively formed on the first grinding surface and the second grinding surface.

[0017] Preferably, the diameter of the through hole is 0.8 mm-3 mm.

[0018] Preferably, the thickness of the bottom wall of the fourth container is 15 mm-60 mm.

[0019] Preferably, the fourth container is provided with a heating device.

[0020] In some embodiments of the present invention, the second container forms two or more outlets.

[0021] Preferably, the two or more outlets of the second container are spaced apart and arranged around the ultrasonic transducer.

[0022] Preferably, the outlet of the second container is provided with an on-off switch.

[0023] Preferably, the second container is provided with a heating device.

[0024] In some embodiments of the present invention, the distance between the ultrasonic transducer and the inner bottom surface of the first container is 2 mm-20 mm.

[0025] Preferably, the bottom of the first container forms an outlet, and the outlet of the first container is provided with a bottom plug.

[0026] Preferably, a heating device is provided on the first container.

[0027] In some embodiments of the present invention, the metal powder preparation device further includes: a collecting container, wherein the collecting container is connected to the outlet of the first container.

[0028] According to another aspect of the present invention, a method for preparing metal powder is provided, and metal powder is prepared by using the above-mentioned metal powder preparation device, comprising the following steps: adding metal and heat-resistant oil to a stirring and heating device, heating to a specified temperature and keeping the temperature for a period of time, and stirring evenly to obtain a mixed metal solution; starting a grinding device, and conveying the mixed metal solution to the grinding device for grinding and crushing, and the mixed metal solution forms an emulsion after grinding; after a certain amount of the emulsion is conveyed to a first container, the emulsion is ultrasonically subjected to an ultrasonic transducer in the first container for a period of time, or the emulsion is directly dropped on the ultrasonic transducer when conveyed to the first container, and then naturally falls after being ultrasonicated, to obtain a mixed solution of metal powder and heat-resistant oil; separating the mixed solution to obtain metal powder.

[0029] In some embodiments of the present invention, the temperature-resistant oil is selected from one or more of peanut oil, castor oil, olive oil, silicone oil, and rosin.

[0030] In some embodiments of the present invention, the metal is a tin alloy.

[0031] Preferably, the tin alloy includes Sn and one or more selected from Pb, Sb, Bi, Cu, Ag, and In. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0033] Figure 1 It is a schematic diagram of the overall structure of the metal powder preparation device of the present invention;

[0034] Figure 2 is a schematic structural diagram of a fourth container of the present invention;

[0035] Figure 3 It is a schematic structural diagram of the grinding disc of the present invention;

[0036] Figure 4 is a scanning electron microscope image of the SnBi58-Type6 sample prepared in Example 1;

[0037] Figure 5 is a scanning electron microscope image of the SnAg3Cu0.5-Type6 sample prepared in Example 2;

[0038] Figure 6 is a scanning electron microscope image of the SnAg3Cu0.5-Type7 sample prepared in Example 3;

[0039] Figure 7 is a scanning electron microscope image of the SnAg3Cu0.5-Type8 sample prepared in Example 4;

[0040] Figure 8 is a scanning electron microscope image of the SnBi43Sb1.5Ag0.5-Type8 sample prepared in Example 5;

[0041] Fig. 9 This is a scanning electron microscope image of the SnBi58-Type9 sample prepared in Example 6.

[0042] The reference numerals in the accompanying drawings represent the following:

[0043] 1. Preprocessing module;

[0044] 11. stirring and heating device; 111. first driver; 112. third container; 113. stirring paddle; 114. valve; 115. fourth container cover;

[0045] 12. second driver; 13. fourth container; 131. through hole; 14. grinding disc; 141. scraper; 143. guide channel;

[0046] 2. Preparation module; 21. Second container; 22. Ultrasonic transducer; 23. First container; 24. Bottom plug;

[0047] 3. Collection container. DETAILED DESCRIPTION

[0048] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0049] When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are only examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0050] In the description of the present application, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances. In addition, in the description of the present application, unless otherwise specified, "multiple" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0051] As the requirements for chip design and manufacturing of electronic terminal products increase, higher requirements are also put forward for metal powders used as welding materials for microelectronic packaging interconnection, such as solder powder, especially for the particle size and particle size distribution of solder powder. At present, solder powder with particle size and particle size distribution of Type 3 (25μm-45μm), Type 4 (20μm-38μm), and Type 5 (15μm-25μm) is often prepared by centrifugal atomization, ultrasonic atomization, and gas atomization. However, for solder powders with finer particle sizes of Type 6 (5μm-15μm), Type 7 (2μm-11μm), Type 8 (2μm-8μm), and Type 9 (1μm-5μm), the powder yield is low, and it is easy to agglomerate, and it is also difficult to sort.

[0052] In addition, although ultrafine powders are currently obtained through high-power ultrasonic dispersion and emulsification, as well as filtration separation and other processes, high-power ultrasonic waves directly act on the metal mixture, and it is impossible to ensure that all the metal liquids are evenly acted on by the ultrasonic waves, which will affect the powder output ratio of ultrafine powders, and the action time is relatively long. The high-power ultrasonic device works for a long time in a high-temperature environment, which affects its lifespan, and therefore cannot operate continuously, resulting in low production efficiency.

[0053] Based on this, the present invention proposes a metal powder preparation device and a preparation method, which can not only realize the preparation of ultrafine metal powder, but also realize the preparation of ultrafine particle size powder of specific specifications through the control process. The particle size is controllable. At the same time, the metal powder has low oxygen content and high yield. The metal powder preparation is convenient and fast, the equipment is small and convenient, and can be used for laboratory-level ultrafine powder production.

[0054] The present application discloses a metal powder preparation device. Figure 1 As shown, the metal powder preparation device includes a pretreatment module 1 and a preparation module 2.

[0055] The pretreatment module 1 includes a stirring and heating device 11 and a grinding device connected to the outlet of the stirring and heating device 11, wherein the stirring and heating device 11 is used to heat and melt the metal raw materials for preparing metal powder and stir and mix the molten metal melt with heat-resistant oil evenly, and the grinding device is used to grind and crush the mixed metal solution of the metal melt and the heat-resistant oil.

[0056] The preparation module 2 comprises a first container 23 connected to the outlet of the grinding device and an ultrasonic transducer 22 disposed in the first container 23, wherein the ultrasonic transducer 22 in the first container 23 is used to perform ultrasonic treatment on the emulsion.

[0057] By using the metal powder preparation device in the present technical solution, first, according to the liquidus line T of the metal, a stirring and heating device 11 is used to stir metal raw materials such as solder alloy and heat-resistant oil under high temperature conditions to obtain a uniform mixed metal solution, and then the mixed metal solution is fully ground and crushed using a grinding device, and then the emulsion obtained by grinding is ultrasonically treated with a high-frequency vibrating ultrasonic transducer 22 to obtain a mixed solution of metal powder and heat-resistant oil. After the mixed solution is separated, metal powders such as ultrafine solder powder can be obtained, thereby realizing the preparation of ultrafine metal powder.

[0058] In some embodiments of the present invention, the outlet of the grinding device is directed toward the ultrasonic transducer 22 .

[0059] By directing the outlet of the grinding device toward the ultrasonic transducer 22, the outlet of the first container 23 and the ultrasonic transducer 22 can be closed before or before the grinding device is used to start grinding the mixed metal solution, so that the emulsion is continuously transported to the first container 23 until the emulsion fills at least a portion of the space in the first container 23, and then the ultrasonic transducer 22 is turned on for ultrasonication to complete the first ultrasonic preparation process; or, the ultrasonic transducer 22 can be turned on before or before the grinding device is used to start grinding the mixed metal solution, so that when the emulsion is transported to the first container 23, the emulsion can directly fall on the high-frequency vibrating ultrasonic transducer 22 to complete the second ultrasonic preparation process.

[0060] Therefore, the present invention can either choose to turn on the ultrasonic transducer 22 for ultrasonication after the emulsion fills part of the space of the first container 23, or choose to turn on the ultrasonic transducer 22 in advance, and the ultrasonic transducer 22 completes ultrasonication while the emulsion continues to enter the first container 23, and the emulsion is continuously output from the first container 23 after ultrasonication, thereby realizing the preparation of ultrafine metal powder under two different processes, and the preparation of ultrafine particle size powder of specific specifications can be realized by controlling the process.

[0061] In some embodiments of the present invention, Figure 1 As shown, a second container 21 is provided between the grinding device and the first container 23 , the second container 21 connects the grinding device and the first container 23 , and an outlet of the second container 21 points to the ultrasonic transducer 22 .

[0062] By transferring the emulsion through the second container 21, the production rhythm can be better regulated, and by directing the outlet of the second container 21 to the ultrasonic transducer 22 instead of directly directing the outlet of the grinding device to the ultrasonic transducer 22, the flexibility of the structural design and relative arrangement of the grinding device and the first container 23 can be improved.

[0063] In some embodiments of the present invention, Figure 1As shown, the second container 21 has more than two outlets.

[0064] By increasing the number of outlets of the second container 21 , the emulsion can be made to fall onto the surface of the ultrasonic transducer 22 more evenly, thereby improving the ultrasonic effect of the ultrasonic transducer 22 on the emulsion.

[0065] In some embodiments of the present invention, Figure 1 As shown, the two or more outlets of the second container 21 are arranged at intervals around the ultrasonic transducer 22 , which can further improve the uniformity of the emulsion falling on the surface of the ultrasonic transducer 22 .

[0066] Preferably, the two or more outlets of the second container 21 are evenly arranged around the ultrasonic transducer 22 .

[0067] It should be noted that, in other embodiments of the present invention, when the outlet of the grinding device directly points to the ultrasonic transducer 22, the outlet of the grinding device can be set to a plurality of small holes, and the small holes are grouped. Each group of small holes is indirectly pointed to the ultrasonic transducer 22 through a pipe, and the outlets of the multiple pipes are spaced and evenly arranged around the ultrasonic transducer 22 to achieve uniform ultrasound of the emulsion.

[0068] In some embodiments of the present invention, an on-off switch (not shown) is provided at the outlet of the second container 21, and the on-off switch can be used to control the timing and speed of conveying the emulsion from the second container 21 to the first container 23. For example, when performing the above-mentioned first ultrasonic preparation process, the on-off switch can be turned off first, and after the emulsion received in the second container 21 reaches a certain amount, the on-off switch can be turned on to centrally convey the emulsion to the first container 23. Alternatively, when performing the above-mentioned second ultrasonic preparation process, the on-off switch can be kept on and the flow rate can be adjusted so that the second container 21 continuously receives the emulsion and the emulsion continuously falls on the ultrasonic transducer 22 at a certain flow rate.

[0069] Furthermore, when the second container 21 has multiple outlets, an on-off switch can be selectively set at each outlet of the second container 21, or multiple outlets of the second container 21 are gathered together near one side of the second container 21, and an on-off switch is centrally set at the gathering point.

[0070] It should be noted that, in other embodiments of the present invention, when the small hole of the grinding device is directed toward the ultrasonic transducer 22 through the outlet of the above-mentioned pipeline, the on-off switch can also be set at the outlet of the pipeline. In addition, it is only necessary to set an emulsion temporary storage space on the side where the on-off switch of the pipeline is located on the grinding device, so that the emulsion can be centrally transported to the first container 23.

[0071] In some embodiments of the present invention, a heating device (not shown) is provided on the second container 21. The heating device on the second container 21 can heat and keep the emulsion warm to prevent the temperature of the emulsion from dropping after leaving the grinding device, thereby affecting the subsequent ultrasonic effect on the emulsion.

[0072] In some embodiments of the present invention, Figure 1 As shown, the stirring and heating device 11 includes a third container 112, a stirring paddle 113, a first driver 111 and a heating device.

[0073] The stirring paddle 113 is disposed in the third container 112 , and the first driver 111 is connected to the stirring paddle 113 . By turning on the first driver 111 , the stirring paddle 113 can be driven to stir in the third container 112 directly or indirectly.

[0074] The heating device is disposed on the third container 112 , and the heating device on the third container 112 can melt the metal added into the third container 112 into a melt, and the melt and the temperature-resistant oil are stirred and evenly mixed by the stirring paddle 113 to obtain a mixed metal solution.

[0075] Furthermore, the first driver 111 includes but is not limited to power machinery such as an electric motor, and the output shaft of the first driver 111 can be coaxially connected to the stirring paddle 113 or indirectly connected through a transmission mechanism.

[0076] In some embodiments of the present invention, Figure 1 As shown, an outlet is formed at the bottom of the third container 112, and a valve 114 is provided at the outlet of the third container 112. By arranging the outlet and the valve 114 at the bottom of the third container 112, the metal can be fully melted in the third container 112 and the molten metal and the heat-resistant oil can be evenly stirred to obtain a mixed metal solution. Then, the valve 114 is opened to conveniently and efficiently transport the mixed metal solution to the grinding device for subsequent grinding and crushing processes.

[0077] In this embodiment, the valve 114 may specifically adopt a butterfly valve structure.

[0078] In other embodiments of the present invention, according to actual process requirements, an outlet may be provided on the side wall or top of the third container 112 to transport the raw materials to the grinding device by tilting or pouring the third container 112, which is not limited here.

[0079] In some embodiments of the present invention, Figure 1 As shown, the grinding device includes a fourth container 13 , a grinding disc 14 and a second drive 12 .

[0080] The inner bottom surface of the fourth container 13 forms a first grinding surface; the grinding disc 14 is arranged in the fourth container 13, and a second grinding surface spaced apart from the first grinding surface is formed on the side of the grinding disc 14 facing the first grinding surface; the second driver 12 is connected to the grinding disc 14.

[0081] A plurality of through holes 131 are formed on the bottom wall of the fourth container 13 , and the through holes 131 communicate with the first grinding surface and the outside of the fourth container 13 .

[0082] After the mixed metal solution enters the fourth container 13, the mixed metal solution will continue to flow into the gap between the first grinding surface and the second grinding surface. The second driver 12 can drive the grinding disc 14 to rotate, so that the second grinding surface rotates relative to the first grinding surface, and the mixed metal solution can be continuously ground and crushed. The emulsion formed by the grinding and crushing can be directly transported to the first container 23 through the through hole 131 without setting the second container 21, or can be transported to the second container 21 first and then transferred to the first container 23 when the second container 21 is set.

[0083] Furthermore, the diameter of the through hole 131 is 0.8 mm to 3 mm, and can be reasonably designed according to the type (particle size and particle size distribution) of the metal powder.

[0084] Furthermore, the second driver 12 includes but is not limited to power machinery such as an electric motor, and the output shaft of the second driver 12 can be coaxially connected to the grinding disc 14 or indirectly connected through a transmission mechanism.

[0085] In some embodiments of the present invention, Figure 2 and Figure 3 As shown, the first grinding surface is a concave conical surface, and the second grinding surface is a convex conical surface matched with the first grinding surface.

[0086] By setting a concave conical surface as the first grinding surface and a convex conical surface as the second grinding surface, the grinding area can be increased, the grinding and crushing efficiency and grinding and crushing effect can be improved, and the mixed metal solution can naturally converge to the middle of the first grinding surface and the second grinding surface, which is beneficial to further improve the grinding and crushing effect and facilitate the natural discharge of the fully ground emulsion through the through hole 131.

[0087] Furthermore, the cone angle of the concave conical surface is 0.5°-8°. It should be noted that the cone angle of the concave conical surface is not particularly limited. Those skilled in the art can make reasonable choices based on actual needs. As some specific examples, the cone angle of the concave conical surface can be 0.5°, 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, etc.

[0088] In some embodiments of the present invention, Figure 3As shown, a plurality of linear guide channels 143 are formed on the first grinding surface and / or the second grinding surface, and the guide channels 143 extend from the center of the first grinding surface and / or the second grinding surface to the outer circle.

[0089] The mixed metal solution can flow from the periphery to the center through the guide channel 143 , thereby improving the uniform distribution of the mixed metal solution in the gap between the first grinding surface and the second grinding surface.

[0090] It should be noted that the guide channel 143 can be linear or arc-shaped. When the guide channel 143 is arc-shaped, the arc-shaped opening can be set in the same direction as the rotation direction of the grinding disc 14 .

[0091] Preferably, the guide channel 143 is opened on the second grinding surface, that is, the guide channel 143 is arranged on the grinding disk 14 .

[0092] Preferably, the plurality of guide channels 143 are evenly distributed around the axis of the grinding disc 14 .

[0093] In some embodiments of the present invention, Figure 3 As shown, a plurality of scrapers 141 are connected to the outer periphery of the grinding disc 14 , and a gap is arranged between the scrapers 141 and the inner bottom of the fourth container 13 .

[0094] The scraper 141 can extend the mixed metal solution dispersed on the edge of the bottom surface of the fourth container 13, so that the mixed metal solution is evenly distributed on the bottom of the fourth container 13 and flows toward the center along the slope.

[0095] It should be noted that the side of the scraper 141 close to the first grinding surface may have the same inclination angle as the first grinding surface (second grinding surface).

[0096] Furthermore, the number of the scrapers 141 may be one, two, three, four, five or six, etc.

[0097] Furthermore, the scraper 141 protrudes toward the inner bottom of the fourth container 13 by 0.1 mm to 1 mm compared to the second grinding surface toward the first grinding surface.

[0098] In some embodiments of the present invention, evenly distributed grinding protrusions (not shown) are formed on the first grinding surface and the second grinding surface respectively, and the mixed metal solution can be better ground and crushed by the grinding protrusions.

[0099] It should be noted that the grinding protrusions can be an integrally formed structure made of the same material as the grinding disc 14 (fourth container 13), that is, the surface of the grinding disc 14 (fourth container 13) has a certain roughness to form grinding protrusions for grinding and crushing.

[0100] In the present invention, the surface roughness of the grinding disc 14 and the size of the gap between the second grinding surface of the grinding disc 14 and the first grinding surface of the fourth container 13 can be reasonably designed according to the model of the prepared metal powder.

[0101] In some embodiments of the present invention, the thickness of the bottom wall of the fourth container 13 is 15 mm-60 mm. It should be understood that the length of the through hole 131 is 15 mm-60 mm.

[0102] In some embodiments of the present invention, a heating device (not shown) is provided on the fourth container 13. The heating device on the fourth container 13 can be used to heat and keep the mixed metal solution warm, thereby preventing the mixed metal solution from dropping in temperature after leaving the third container 112 (stirring and heating device 11) and affecting the grinding and crushing effect of the mixed metal solution.

[0103] In some embodiments of the present invention, Figure 1 As shown, the ultrasonic transducer 22 is close to the inner bottom surface of the first container 23.

[0104] Preferably, the outlet of the grinding device or the outlet of the second container 21 is directed toward the upper middle portion of the ultrasonic transducer 22 .

[0105] It should be noted that in the above-mentioned first ultrasonic preparation process, when the emulsion that needs ultrasound enters the first container, the ultrasonic transducer is turned on, and the emulsion entering the first container should not be too much or too little, so as to facilitate complete ultrasound of the emulsion (too much ultrasound may not be sufficient and the energy is insufficient, and too little ultrasound may not cover the ultrasonic head of the ultrasonic transducer, and the ultrasonic energy evaporates in the atmosphere without contacting the emulsion).

[0106] Furthermore, the distance between the ultrasonic transducer 22 and the inner bottom surface of the first container 23 is 2 mm-20 mm.

[0107] In some embodiments of the present invention, Figure 1 As shown, an outlet is formed at the bottom of the first container 23, and a bottom plug 24 is provided at the outlet of the first container 23. By arranging the outlet and the bottom plug 24 at the bottom of the first container 23, after the first ultrasonic preparation process is completed and the emulsion in the first container 23 is fully ultrasonicated, the bottom plug 24 can be opened to conveniently and efficiently transport the mixed solution of the metal powder and the heat-resistant oil out, or when the second ultrasonic preparation process is performed, the bottom plug 24 can be opened in advance so that the emulsion is directly discharged from the outlet of the first container 23 after being ultrasonicated by the ultrasonic transducer 22, so as to facilitate the subsequent separation of the metal powder.

[0108] Specifically, the bottom surface of the bottom plug 24 in the present invention is just flush with the first container 23 and serves as a part of the first container 23 during the reaction process.

[0109] In other embodiments of the present invention, according to actual process requirements, an outlet may be provided on the side wall or top of the first container 23 to release the mixed solution of metal powder and heat-resistant oil by tilting or pouring the first container 23.

[0110] In some embodiments of the present invention, the volume of the first container 23 is 2 to 10 times the volume of the second container 21, ensuring that the emulsion received by the second container 21 can submerge part of the length of the ultrasonic transducer 22 in the first container 23 without excessively filling the first container 23.

[0111] In some embodiments of the present invention, a heating device is provided on the first container 23. The heating device on the first container 23 can heat and keep the emulsion transported to the first container 23 warm, thereby preventing the temperature of the emulsion from dropping after leaving the grinding device or the second container 21, thereby affecting the ultrasonic effect on the emulsion.

[0112] In some embodiments of the present invention, Figure 1 As shown, the metal powder preparation device also includes a collecting container 3, which is connected to the outlet of the first container 23. The mixed solution of metal powder and heat-resistant oil can be collected through the collecting container 3 to facilitate the subsequent separation of the metal powder.

[0113] In some embodiments of the present invention, the third container 112, the fourth container 13, the second container 21, the first container 23 and the collection container 3 are arranged in sequence from top to bottom, and the transfer of materials in each process can be completed by using gravitational potential energy.

[0114] In some embodiments of the present invention, two or more groups of stirring and heating devices 11 (third container 112 ) may be provided above the grinding device (fourth container 13 ), and the two or more groups of third containers 112 are arranged at intervals around the axis of the fourth container 13 .

[0115] For example, the number of the stirring and heating devices 11 may be 2, 3, 4, 5, etc.

[0116] In some embodiments of the present invention, Figure 1 As shown, the top opening of the fourth container 13 is sealed by a fourth container cover 115, and the third container 112 is placed on the flange of the fourth container cover 115. The fourth container cover 115 is evenly distributed with flanges equal to the number of the stirring and heating equipment 11 for placing the third containers 112, and a motor hole for driving the grinding disc 14 is set in the center of the fourth container cover 115.

[0117] Preferably, the outlet of the third container 112 deviates from the middle area of ​​the fourth container 13, so that the mixed metal solution flowing from the third container 112 to the fourth container 13 can fall on the scraper 141, be better extended by the scraper 141 and flow toward the center along the bottom slope of the fourth container 13.

[0118] In other embodiments of the present invention, Figure 1 As shown, the third container 112 is an annular cylindrical barrel with flanges at both ends. The upper flange is connected to the flange seat of the motor (first driver 111), and the lower flange is connected to the butterfly valve. The butterfly valve controls the opening or closing of the bottom of the third container 112. When the butterfly valve is closed, the butterfly valve is equivalent to the bottom of the third container 112, and metal and heat-resistant oil can be contained at this time. When the butterfly valve is opened, the third container 112 is connected to the fourth container 13, and the uniform mixed metal solution formed in the third container 112 flows into the edges around the fourth container 13.

[0119] In some embodiments of the present invention, the first container 23, the second container 21, the third container 112 and the fourth container 13 are preferably high temperature resistant crucibles.

[0120] In addition, the collecting container 3 can also be a high-temperature resistant crucible.

[0121] Specifically, in the present invention, the second container 21 may be a three-way funnel, and the first container 23 may be a three-mouth ultrasonic crucible.

[0122] In some embodiments of the present invention, the heating devices on the first container 23, the second container 21, the third container 112 and the fourth container 13 include but are not limited to electric heating wires, heating sleeves or high-frequency electromagnetic heating.

[0123] The first container 23, the second container 21, the third container 112 and the fourth container 13 can be heated by a heating device according to the liquidus line T of the metal alloy, specifically, they can be heated to a temperature of T+20°C to T+80°C.

[0124] This embodiment also proposes a metal powder preparation method, which uses the above-mentioned metal powder preparation device to prepare metal powder. The metal powder preparation method includes the following steps:

[0125] 1) Add metal and heat-resistant oil into the stirring and heating device 11, heat to a specified temperature and keep the temperature for a period of time, then stir evenly to obtain a mixed metal solution.

[0126] 2) Turn on the grinding device, and convey the mixed metal solution to the grinding device for grinding and crushing. After the mixed metal solution is ground and crushed, an emulsion is formed.

[0127] 3) After a certain amount of the emulsion is transported to the first container 23, the emulsion is ultrasonically treated by the ultrasonic transducer 22 in the first container 23 for a period of time, or the emulsion falls directly on the ultrasonic transducer when transported to the first container and then falls naturally after being ultrasonicated, to obtain a mixed solution of metal powder and heat-resistant oil.

[0128] In this step, the ultrasonic transducer can ultrasonicate the emulsion in two different processes, and the preparation of ultrafine particle size powder of specific specifications can be achieved by controlling the process.

[0129] 4) Separating the mixed solution to obtain metal powder.

[0130] In some embodiments of the present invention, the heat-resistant oil is selected from one or more of peanut oil, castor oil, olive oil, silicone oil, and rosin.

[0131] In some embodiments of the present invention, the metal includes but is not limited to an alloy or a pure metal, for example, the alloy is a tin alloy.

[0132] Furthermore, the components of the tin alloy include Sn and one or more selected from Pb, Sb, Bi, Cu, Ag, and In.

[0133] In some embodiments of the present invention, the metal powder preparation process is carried out in an atmosphere of protective gas. Preferably, when each process is carried out in the third container, the fourth container, the second container and the first container, nitrogen or a rare gas such as argon and other protective gases are continuously introduced into each container to more effectively control the oxygen content of the metal powder.

[0134] Specifically, in the present invention, according to the different particle sizes of the produced ultrafine metal powder, the preparation methods of the metal powder using the metal powder preparation device of the present invention include the following two methods.

[0135] The first preparation method

[0136] First, valve 114 needs to be closed, and then metal and heat-resistant oil are added to the third container 112, and the heating function of the third container 112 is turned on, heated to a certain temperature (T+20℃-T+80℃), and the power of the first driver 111 is turned on, and the speed of the first driver 111 is adjusted to 500rpm to 8000rpm, and the stirring time is 2-4 minutes, so that the metal and the heat-resistant oil form a uniform mixed metal solution.

[0137] After the stirring stops, the second driver 12 is started, and the second driver 12 drives the grinding disc 14 to rotate at a speed of 300rpm-6000rpm. The on-off switch of the three-way funnel is turned off, the heating functions of the fourth container 13 and the three-way funnel are turned on, and the valve 114 switch above the fourth container cover 115 is turned on at the same time, and the uniformly mixed metal solution flows from the third container 112 into the fourth container 13. Under the action of the scraper 141, the uniformly mixed metal solution is uniformly dispersed on the bottom surface of the fourth container 13. At the same time, since the bottom surface of the grinding disc 14 has a certain slope, the uniformly mixed metal solution slowly converges to the center through the guide channel 143 on the bottom surface of the grinding disc 14 and the gap between the fourth container 13 and the grinding disc 14. In this process, the grinding disc 14 and the fourth container 13 grind and crush the uniformly mixed metal solution, and the emulsion obtained by grinding naturally flows into the three-way funnel through the through hole 131 at the bottom of the fourth container 13.

[0138] When the emulsion in the three-way funnel reaches a certain amount, the heating and heat preservation functions of the three-way funnel and the three-mouth ultrasonic crucible are turned on, and their temperatures are set and monitored. The three-way funnel and the three-mouth ultrasonic crucible are set to corresponding temperatures (T+20°C to T+80°C) according to the liquidus line T of the metal. The specific temperature needs to be determined according to the properties of the metal. The bottom plug 24 is tightly closed, the three-way funnel switch is turned on, and then the emulsion enters the three-mouth ultrasonic crucible through the three-way funnel. After all the emulsion in the three-way funnel enters the three-mouth ultrasonic crucible, the three-way funnel switch is turned off.

[0139] When the temperature of the emulsion inside the three-mouth ultrasonic crucible reaches the indicator line (not shown), turn on the ultrasonic transducer 22, set the frequency to 10-50kHz, and the ultrasonic time to 3-15 minutes. After the time is reached, stop the ultrasound, open the bottom plug 24, collect the solution in the three-mouth ultrasonic crucible and cool it naturally to obtain a mixed solution of ultrafine metal powder and heat-resistant oil. Then separate the metal powder and the heat-resistant oil. Separation methods include static precipitation, centrifugal separation, filtration, etc. After separation, the prepared ultrafine powder needs to be cleaned, and the cleaning agent includes anhydrous ethanol, acetone, and trichloroethylene.

[0140] The second preparation method

[0141] First, valve 114 needs to be closed, and then metal and heat-resistant oil are added to the third container 112, and the heating function of the third container 112 is turned on, heated to a certain temperature (T+20℃-T+80℃), and the power of the first driver 111 is turned on, and the speed of the first driver 111 is adjusted to 500rpm to 8000rpm, and the stirring time is 2-4 minutes, so that the metal and the heat-resistant oil form a uniform mixed metal solution.

[0142] After the stirring stops, the second driver 12 is started, and the second driver 12 drives the rotating grinding disc to rotate at a speed of 300rpm-6000rpm. The heating functions of the fourth container 13 and the three-way funnel are turned on, the bottom plug 24 is opened, and the ultrasonic transducer 22 is started, and the frequency is set to 40-100kHz. The three-way funnel is connected to the fourth container 13 on the top and the three ultrasonic crucibles on the bottom. The on-off switch on the top of the three-way funnel is turned on and connected to the three ultrasonic crucibles. The valve 114 above the fourth container cover 115 is opened, and the uniformly mixed metal solution obtained after stirring flows from the third container 112 into the fourth container 13. The uniformly mixed metal solution is uniformly dispersed on the bottom surface of the fourth container 13 under the action of the scraper 141. At the same time, since the bottom surface of the grinding disc 14 has a certain slope, the uniformly mixed metal solution slowly converges to the center through the guide channel 143 on the bottom surface of the grinding disc 14 and the gap between the fourth container 13 and the grinding disc 14. In this process, the grinding disc 14 and the fourth container 13 grind and crush the uniformly mixed metal solution, and the emulsion obtained by grinding naturally flows into the three-way funnel through the through hole 131 at the bottom of the fourth container 13, and the flow rate is stable and uniform.

[0143] The emulsion flows out stably through the outlets on both sides of the lower end of the three-way funnel. The outflowing emulsion falls on the ultrasonic head of the ultrasonic transducer 22 under the action of gravitational potential energy. After passing through the ultrasonic head, a mixed solution of ultrafine powder and heat-resistant oil is obtained, which flows out through the outlet at the bottom of the three-mouth ultrasonic crucible. This process can be carried out stably and continuously. The collection container 3 collects the solution in the three-mouth ultrasonic crucible and cools it naturally to obtain a mixed solution of ultrafine metal powder and heat-resistant oil. The metal powder and the heat-resistant oil are then separated. Separation methods include static sedimentation, centrifugal separation, filtration, etc. After separation, the prepared ultrafine powder also needs to be cleaned, and the cleaning agent includes anhydrous ethanol, acetone, and trichloroethylene.

[0144] The metal powder preparation method of the present application will be further described below in conjunction with specific examples, and each example is carried out in a protective gas atmosphere of nitrogen.

[0145] Example 1

[0146] The first preparation method is to prepare SnBi58 ultrafine solder powder

[0147] SnBi58 and heat-resistant oil are added to the third container in a volume ratio of 1:12, the temperature is set to 190°C, the speed of the first driver is 1500rmp, and a uniform mixed solution is formed after stirring, and then enters the fourth container through a valve, the speed of the second driver is 1000rmp, and a 1.5 mm through hole is opened at the bottom of the fourth container. After grinding, an emulsion is formed and enters the three-mouth ultrasonic crucible through a three-way funnel. The ultrasonic transducer is set to a frequency of 15kHz and the ultrasonic time is 8 minutes. After completion, it enters the collection container from the bottom of the three-mouth crucible and is cooled to obtain a mixed solution of ultrafine powder and heat-resistant oil. Ultrafine powder is obtained by static precipitation, and then ultrafine solder powder is obtained by washing with acetone. After testing, the powder with a particle size of T6 (5-15μm) accounts for 93%, the oxygen content is 280ppm, the sphericity is good, and it meets the standard technical indicators of the electronics industry. The scanning electron microscope picture is as follows Figure 4 shown.

[0148] Example 2

[0149] The first preparation method is to prepare SnAg3Cu0.5 ultrafine solder powder

[0150] SnAg3Cu0.5 and heat-resistant oil are added to the third container in a volume ratio of 1:13, the temperature is set to 275°C, the speed of the first driver is 2000rmp, and a uniform mixed solution is formed after stirring, and then enters the fourth container through a valve, the speed of the second driver is 1000rmp, and a 1.3 mm through hole is opened at the bottom of the fourth container. After grinding, an emulsion is formed and enters the three-mouth ultrasonic crucible through a three-way funnel. The ultrasonic transducer is set to a frequency of 16kHz and an ultrasonic time of 8 minutes. After completion, it enters the collection container from the bottom of the three-mouth crucible and is cooled to obtain a mixed solution of ultrafine powder and heat-resistant oil. Ultrafine powder is obtained by static precipitation, and then ultrafine solder powder is obtained by washing with acetone. After testing, the powder with a particle size of T6 (5-15μm) accounts for 95%, the oxygen content is 260ppm, the sphericity is good, and it meets the standard technical indicators of the electronics industry. The scanning electron microscope image is as follows Figure 5 shown.

[0151] Example 3

[0152] The first preparation method is to prepare SnAg3Cu0.5 ultrafine solder powder

[0153] SnAg3Cu0.5 and heat-resistant oil are added to the third container in a volume ratio of 1:14, the temperature is set to 278°C, the speed of the first driver is 2200rmp, and a uniform mixed solution is formed after stirring, and then enters the fourth container through a valve, the speed of the second driver is 900rmp, and a 1.2 mm through hole is opened at the bottom of the fourth container. After grinding, an emulsion is formed and enters the three-mouth ultrasonic crucible through a three-way funnel. The ultrasonic transducer is set to a frequency of 16kHz and an ultrasonic time of 10 minutes. After completion, it enters the collection container from the bottom of the three-mouth crucible and is cooled to obtain a mixed solution of ultrafine powder and heat-resistant oil. Ultrafine powder is obtained by static precipitation, and then ultrafine solder powder is obtained by washing with acetone. After testing, the powder with a particle size of T7 (2-11μm) accounts for 94%, the oxygen content is 350ppm, the sphericity is good, and it meets the standard technical indicators of the electronics industry. The scanning electron microscope picture is as follows Figure 6 shown.

[0154] Example 4

[0155] The second preparation method is to prepare SnAg3Cu0.5 ultrafine solder powder

[0156] SnAg3Cu0.5 and heat-resistant oil are added to the third container in a volume ratio of 1:14, the temperature is set to 280°C, the speed of the first driver is 2500 rpm, and a uniform mixed solution is formed after stirring. Then it enters the fourth container through a valve, the speed of the second driver is 850 rpm, and a 1.2 mm through hole is opened at the bottom of the fourth container. After grinding, an emulsion is formed and naturally flows into the three-way funnel through the through hole at the bottom of the fourth container, and the flow is stable and uniform. The emulsion flows out steadily through the outlets on both sides of the lower end of the three-way funnel. The outflowing emulsion falls on the ultrasonic head of the ultrasonic transducer under the action of gravitational potential energy. The ultrasonic transducer is set to a frequency of 68kHz. After passing through the ultrasonic head, a mixed solution of ultrafine powder and heat-resistant oil is obtained, which flows out through the outlet at the bottom of the three-mouth ultrasonic crucible, enters the collection container and is cooled to obtain a mixed solution of ultrafine powder and heat-resistant oil. The ultrafine powder is obtained by filtration separation, and then the ultrafine solder powder is obtained by washing with acetone. The powder with a particle size of T8 (2-8μm) accounts for 93% after testing, and the oxygen content is 480ppm. The sphericity is good, which meets the standard technical indicators of the electronics industry. The scanning electron microscope picture is as follows Figure 7 shown.

[0157] Example 5

[0158] The second preparation method is to prepare SnBi43Sb1.5Ag0.5 ultrafine solder powder

[0159] SnBi43Sb1.5Ag0.5 and heat-resistant oil were added into the third container at a volume ratio of 1:14, the temperature was set at 200°C, the speed of the first driver was 2500 rpm, a uniform mixed solution was formed after stirring, and then entered into the fourth container through a valve, the speed of the second driver was 850 rpm, a 1.2 mm through hole was opened at the bottom of the fourth container, an emulsion was formed after grinding, and naturally flowed into the three-way funnel through the through hole at the bottom of the fourth container, and the flow rate was stable and uniform. The emulsion flows out steadily through the outlets on both sides of the lower end of the three-way funnel. The outflowing emulsion falls on the ultrasonic head of the ultrasonic transducer under the action of gravitational potential energy. The ultrasonic transducer is set at a frequency of 68kHz. After passing through the ultrasonic head, a mixed solution of ultrafine powder and heat-resistant oil is obtained, which flows out through the outlet at the bottom of the three-mouth ultrasonic crucible, enters the collection container and is cooled to obtain a mixed solution of ultrafine powder and heat-resistant oil. The ultrafine powder is obtained by filtration separation, and then it is washed with acetone to obtain ultrafine solder powder. After testing, the powder with a particle size of T8 (2-8μm) accounts for 92%, the oxygen content is 470ppm, the sphericity is good, and it meets the standard technical indicators of the electronics industry. The scanning electron microscope picture is as follows Figure 8 shown.

[0160] Example 6

[0161] The second preparation method is to prepare SnBi58 ultrafine solder powder

[0162] SnBi58 and heat-resistant oil were added to the third container in a volume ratio of 1:14, the temperature was set at 195°C, the speed of the first driver was 3000 rpm, a uniform mixed solution was formed after stirring, and then entered the fourth container through a valve, the speed of the second driver was 800 rpm, a 1.1 mm hole was opened at the bottom of the fourth container, an emulsion was formed after grinding, and it naturally flowed into the three-way funnel through the small hole at the bottom of the grinding crucible, and the flow was stable and uniform. The emulsion flows out steadily through the outlets on both sides of the lower end of the three-way funnel. The outflowing emulsion falls on the ultrasonic head of the ultrasonic transducer under the action of gravitational potential energy. The ultrasonic transducer is set to a frequency of 69kHz. After passing through the ultrasonic head, a mixed solution of ultrafine powder and heat-resistant oil is obtained, which flows out through the outlet at the bottom of the three-mouth ultrasonic crucible, enters the collection container and is cooled to obtain a mixed solution of ultrafine powder and heat-resistant oil. The ultrafine powder is obtained by filtration separation, and then it is washed with acetone to obtain ultrafine solder powder. The powder with a particle size of T9 (1-5μm) accounts for 92% after testing, and the oxygen content is 650ppm. The sphericity is good, which meets the standard technical indicators of the electronics industry. The scanning electron microscope picture is as follows Fig. 9 shown.

[0163] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A metal powder preparation device, characterized in that: It includes a pretreatment module and a preparation module; The pretreatment module includes a stirring and heating device and a grinding device connected to the outlet of the stirring and heating device; The preparation module comprises a first container connected to the outlet of the grinding device and an ultrasonic transducer disposed in the first container; The outlet of the grinding device is directed toward the ultrasonic transducer; The ultrasonic transducer is arranged close to the inner bottom of the first container.

2. The metal powder preparation device according to claim 1, characterized in that: A second container is arranged between the grinding device and the first container, the outlet of the grinding device is communicated with the inlet of the second container, and the outlet of the second container points to the ultrasonic transducer.

3. The metal powder preparation device according to claim 1, characterized in that: The stirring and heating equipment comprises: The third container; a stirring paddle, the stirring paddle being arranged in the third container; a first driver connected to the stirring paddle; A heating device, wherein the heating device is disposed on the third container; Preferably, the bottom of the third container forms an outlet, and the outlet of the third container is provided with a valve.

4. The metal powder preparation device according to claim 1, characterized in that: The grinding device comprises: a fourth container, wherein the inner bottom of the fourth container forms a first grinding surface; A grinding disc, the grinding disc being arranged in the fourth container, and a second grinding surface spaced apart from the first grinding surface being formed on a side of the grinding disc facing the first grinding surface; a second driver connected to the grinding disc; The bottom wall of the fourth container is formed with a plurality of through holes, wherein the through holes communicate with the first grinding surface and the outside of the fourth container; Preferably, the first grinding surface is a concave conical surface, and the second grinding surface is a convex conical surface adapted to the first grinding surface; Preferably, the concave conical surface has a cone angle of 0.5°-8°; Preferably, a plurality of linear guide channels are formed on the first grinding surface and / or the second grinding surface, and the guide channels extend from the center of the first grinding surface and / or the second grinding surface to the outer circle; Preferably, a plurality of scrapers are connected to the outer periphery of the grinding disc, and the scrapers are spaced apart from the inner bottom of the fourth container; Preferably, the scraper protrudes 0.1 mm to 1 mm toward the inner bottom of the fourth container compared to the second grinding surface toward the first grinding surface; Preferably, the first grinding surface and the second grinding surface are respectively formed with evenly distributed grinding protrusions; Preferably, the diameter of the through hole is 0.8 mm-3 mm; Preferably, the thickness of the bottom wall of the fourth container is 15 mm-60 mm; Preferably, the fourth container is provided with a heating device.

5. The metal powder preparation device according to claim 2, characterized in that: The second container forms more than two outlets; Preferably, the two or more outlets of the second container are arranged around the ultrasonic transducer at intervals; Preferably, the outlet of the second container is provided with an on-off switch; Preferably, the second container is provided with a heating device.

6. The metal powder preparation device according to claim 1, characterized in that: The distance between the ultrasonic transducer and the inner bottom surface of the first container is 2 mm-20 mm; Preferably, the bottom of the first container forms an outlet, and the outlet of the first container is provided with a bottom plug; Preferably, a heating device is provided on the first container.

7. The metal powder preparation device according to claim 1, characterized in that: Also includes: A collecting container is communicated with the outlet of the first container.

8. A method for preparing metal powder, using the metal powder preparation device according to any one of claims 1 to 7 to prepare metal powder, characterized in that: The following steps are involved: Add metal and heat-resistant oil into a stirring and heating device, heat to a specified temperature and keep the temperature for a period of time, then stir evenly to obtain a mixed metal solution; The grinding device is turned on to convey the mixed metal solution to the grinding device for grinding and crushing, and the mixed metal solution is ground to form an emulsion; After a certain amount of the emulsion is transported to the first container, the emulsion is ultrasonically treated by the ultrasonic transducer in the first container for a period of time, or the emulsion falls directly on the ultrasonic transducer when transported to the first container and then falls naturally after being ultrasonicated, to obtain a mixed solution of metal powder and heat-resistant oil; The mixed solution is separated to obtain metal powder.

9. The method for preparing metal powder according to claim 8, characterized in that: The heat-resistant oil is selected from one or more of peanut oil, castor oil, olive oil, silicone oil and rosin.

10. The method for preparing metal powder according to claim 8, characterized in that: The metal is a tin alloy; Preferably, the tin alloy includes Sn and one or more selected from Pb, Sb, Bi, Cu, Ag, and In.

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