Soft magnetic composite powder material for integrally-formed inductor and preparation method and device of soft magnetic composite powder material

Abstract

The invention provides a soft magnetic composite powder material for an integrally-formed inductor and a preparation method and device of the soft magnetic composite powder material, and relates to the technical field of soft magnetic composites.The preparation method comprises the steps that first aerial fog powder, second aerial fog powder and water fog powder are mixed in an airflow mixer, and mixed powder is obtained; preparing a phosphoric acid-acetone solution, and spraying the phosphoric acid-acetone solution to the surface of the mixed powder through a high-pressure atomizing nozzle for phosphating; after phosphating treatment is completed, baking and cooling are conducted; epoxy resin, acetone and a silane coupling agent are mixed, a coupling solution is prepared, and the coupling solution is sprayed to the surface of the baked mixed powder through a high-pressure atomizing nozzle for coating treatment; after coating treatment is completed, granulation, baking and sieving are conducted, and the soft magnetic composite powder for the integrally-formed inductor is obtained.The technical problem that in the prior art, due to the fact that powder is settled and layered due to the density difference, performance fluctuation is large can be solved.

Description

Technical Field

[0001] This invention relates to the field of soft magnetic composite materials technology, specifically to a one-piece molded soft magnetic composite powder for inductors and its preparation method and apparatus. Background Technology

[0002] With the rapid development of emerging technologies such as 5G and the Internet of Things, the market demand for high-performance inductors will continue to grow, becoming an important growth point in the field of electronic components. Molded inductors, with their superior electrical performance, reliable mechanical characteristics, and compact structural design, are redefining electronic power management standards. As a key component in electronic design, they not only meet the current demands for miniaturization and efficiency in devices but also provide a solid foundation for future electronic technology innovation.

[0003] Compared with traditional wire-wound inductors, integrally molded inductors use a soft magnetic composite powder metallurgy process to integrate the soft magnetic composite powder with the coil, achieving a perfect balance between performance and volume. However, the existing soft magnetic composite powder preparation process produces powders that settle and stratify due to density differences, resulting in large performance fluctuations and thus reduced product yield. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a one-piece molded soft magnetic composite powder for inductors and its preparation method and apparatus, which aims to solve the technical problem of large performance fluctuations caused by the sedimentation and stratification of powder due to density differences in the prior art.

[0005] This invention provides a method for preparing a one-piece molded soft magnetic composite powder for inductors, the method comprising: The first aerosol powder, the second aerosol powder, and the water mist powder are mixed in an airflow mixer to obtain a mixed powder, wherein the particle size of the first aerosol powder is larger than the particle size of the water mist powder, which is larger than the particle size of the second aerosol powder. Prepare a phosphoric acid-acetone solution, and spray the phosphoric acid-acetone solution onto the surface of the mixed powder through a high-pressure atomizing nozzle for phosphating treatment; After the phosphating process is completed, bake at the first preset temperature and then cool. Epoxy resin, acetone, and silane coupling agent are mixed to prepare a coupling solution. The coupling solution is then sprayed onto the surface of the baked mixed powder through a high-pressure atomizing nozzle for coating treatment. After the coating process is completed, the material is granulated, baked at the second preset temperature, and sieved to obtain a one-piece molded soft magnetic composite powder for inductors.

[0006] Compared with the prior art, the beneficial effects of the present invention are as follows: Through the preparation method of the integrally molded soft magnetic composite powder for inductors provided by the present invention, the first aerosol powder, the second aerosol powder, and the water mist powder are mixed to achieve the mutual matching of the three powders with multiple particle sizes, which improves the density of the product after molding, thereby improving the magnetic permeability and saturation magnetic induction intensity of the product and reducing losses. By spraying high-speed airflow through a high-pressure atomizing nozzle, the sedimentation and stratification of the mixed powder caused by density differences are destroyed. The high-speed airflow sprayed through the high-pressure atomizing nozzle causes the mixed powder to diffuse and mix through particle collisions. The mixed powder is fluidized and suspended in the cavity to form a circulating vortex, which improves the uniformity and consistency of the mixed powder distribution and reduces the performance fluctuation of the product. Thus, the technical problem of large performance fluctuation caused by the sedimentation and stratification of powder due to density differences in the prior art is solved.

[0007] According to one aspect of the above technical solution, the first aerosol powder, the second aerosol powder, and the water mist powder all include one or more of Fe-Ni-Mo alloy powder, Fe-Ni alloy powder, Fe-Co alloy powder, Fe-Si alloy powder, Fe-Si-Al alloy powder, Fe-Si-Cr alloy powder, Fe-based amorphous alloy powder, Ni-based amorphous alloy powder, Co-based amorphous alloy powder, and Fe-based nanocrystalline powder.

[0008] According to one aspect of the above technical solution, the mass ratio of the first aerosol powder, the second aerosol powder, and the water mist powder is 1:(0.5~2):(0.5~2), the D50 of the first aerosol powder is 20μm~23μm, the D50 of the water mist powder is 10μm~12μm, and the D50 of the second aerosol powder is 6μm~8μm.

[0009] According to one aspect of the above technical solution, the step of mixing the first aerosol powder, the second aerosol powder, and the water mist powder in an airflow mixer to obtain a mixed powder specifically includes: The gas pressure is set to 0.4MPa~0.8MPa, so that the high-pressure atomizing nozzle periodically sprays to generate a high-speed airflow with a flow rate of 100m / s~200m / s and a period of 10s~15s. First aerosol powder, second aerosol powder, and water mist powder are added into the feeding port of the cavity. A pulse valve is installed at the bottom of the cavity with a gas pressure of 0.2MPa~0.6MPa. Mix for 10min~40min.

[0010] According to one aspect of the above technical solution, the step of preparing a phosphoric acid-acetone solution and spraying the phosphoric acid-acetone solution onto the surface of the mixed powder through a high-pressure atomizing nozzle for phosphating treatment specifically includes: Prepare a phosphoric acid-acetone solution with a phosphoric acid to acetone mass ratio of 1:(70~80) and phosphoric acid accounting for 0.01%~0.5% of the mass of the mixed powder. The gas pressure is controlled at 0.3MPa~0.6MPa. The phosphoric acid-acetone solution, along with the gas, is periodically injected through a high-pressure atomizing nozzle to generate a high-speed airflow with a flow rate of 80m / s~160m / s and a period of 10s~15s. A pulse valve is installed at the bottom of the chamber to set the gas pressure to 0.2MPa~0.6MPa. Mix for 10 minutes and let stand for 1h~1.5h.

[0011] According to one aspect of the above technical solution, the step of mixing epoxy resin, acetone, and silane coupling agent to prepare a coupling solution, and spraying the coupling solution onto the surface of the baked mixed powder through a high-pressure atomizing nozzle for coating treatment, specifically includes: Epoxy resin, acetone, and silane coupling agent are mixed to prepare a coupling solution. The mass ratio of epoxy resin, acetone, and silane coupling agent is (40~50):(210~220):1, and the epoxy resin accounts for 2%~5% of the mass of the mixed powder. The gas pressure in the airflow mixer is controlled at 0.4MPa~0.8MPa, so that the high-pressure atomizing nozzle periodically sprays to generate a high-speed airflow with a flow rate of 100m / s~200m / s and a cycle of 10s~15s. A pulse valve is installed at the bottom of the chamber with a gas pressure of 0.2MPa~0.6MPa, and premixing is performed for 10 minutes. The gas pressure in the airflow mixer is controlled at 0.3MPa~0.5MPa. The coupling solution and accompanying gas are periodically injected through a high-pressure atomizing nozzle to generate a high-speed airflow with a velocity of 70m / s~120m / s and a period of 10s~15s. A pulse valve is installed at the bottom of the chamber with a gas pressure of 0.2MPa~0.6MPa. Premixing takes 20min~40min.

[0012] According to one aspect of the above technical solution, the first preset temperature is 100℃~150℃, and the baking time is 1h~3h; the second preset temperature is 40℃~80℃, and the baking time is 1h~3h.

[0013] A second aspect of the present invention is to provide a soft magnetic composite powder for integrally molded inductors, wherein the soft magnetic composite powder for integrally molded inductors is prepared by the above-described method for preparing soft magnetic composite powder for integrally molded inductors.

[0014] A third aspect of the present invention provides an apparatus for preparing a molded soft magnetic composite powder for an inductor, the apparatus being used to perform the above-described method for preparing the molded soft magnetic composite powder for an inductor, the apparatus comprising: Airflow mixer, oven, granulator, vibrating screen; The airflow mixer is used to mix the powders and sequentially spray phosphoric acid-acetone solution and coupling solution for phosphating and coating treatment. The oven is used to bake the mixed powder after phosphating and granulation. The granulator is used to granulate the coated mixed powder; The vibrating screen is used to sieve the mixed powder after granulation and baking.

[0015] Furthermore, the airflow mixer includes a cavity, a waste gas cooling and recovery mechanism connected to the cavity, and a powder collection box; The sidewall of the cavity is provided with several high-pressure atomizing nozzles, the bottom of the cavity is provided with several pulse valves, and the top of the cavity is provided with a feeding port; The top of the cavity is connected to the waste gas cooling and recovery mechanism through a dust filter and a waste gas sealing collection hood; The cavity is connected to the powder collection box via a valve, and the powder collection box has a powder outlet at the bottom; The exhaust gas cooling and recovery mechanism is connected to the powder collection box via another dust filter and an exhaust gas sealing collection hood. Attached Figure Description

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the airflow mixer of the present invention; In the diagram: 1. High-pressure atomizing nozzle; 2. Feed port; 3. Dust filter; 4. Exhaust gas sealing collection hood; 5. Exhaust gas cooling and recovery mechanism; 6. Pulse valve; 7. Valve; 8. Discharge port; 9. Powder collection box; 10. Powder outlet; 11. Cavity; 12. Exhaust gas discharge pipe. Detailed Implementation

[0017] To make the objectives, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present invention will be more thorough and complete.

[0018] The present invention provides a method for preparing a soft magnetic composite powder for integrally molded inductors, the preparation method comprising steps S10 to S14.

[0019] Step S10: Mix the first aerosol powder, the second aerosol powder, and the water mist powder in an airflow mixer to obtain a mixed powder. The particle size of the first aerosol powder is larger than the particle size of the water mist powder, which is larger than the particle size of the second aerosol powder. The first aerosol powder, the second aerosol powder, and the water mist powder all include one or more of the following: Fe-Ni-Mo alloy powder, Fe-Ni alloy powder, Fe-Co alloy powder, Fe-Si alloy powder, Fe-Si-Al alloy powder, Fe-Si-Cr alloy powder, Fe-based amorphous alloy powder, Ni-based amorphous alloy powder, Co-based amorphous alloy powder, and Fe-based nanocrystalline powder.

[0020] Further, the mass ratio of the first aerosol powder, the second aerosol powder, and the water mist powder is 1:(0.5~2):(0.5~2), the D50 of the first aerosol powder is 20μm~23μm, the D50 of the water mist powder is 10μm~12μm, and the D50 of the second aerosol powder is 6μm~8μm.

[0021] It should be noted that, since the water atomized powder has an elliptical or rod-shaped morphology and the gas atomized powder has a near-spherical morphology, the three types of powders have different particle sizes, which improves the density of the product after molding, thereby increasing the magnetic permeability and saturation magnetic induction intensity of the product and reducing losses.

[0022] Furthermore, the mixing process of the airflow mixer specifically includes: setting the gas pressure to 0.4MPa~0.8MPa, so that the high-pressure atomizing nozzle periodically sprays to generate a high-speed airflow with a flow velocity of 100m / s~200m / s and a cycle of 10s~15s; First aerosol powder, second aerosol powder, and water mist powder are added into the feeding port of the cavity. A pulse valve is installed at the bottom of the cavity with a gas pressure of 0.2MPa~0.6MPa. Mix for 10min~40min.

[0023] It should be noted that by spraying high-speed airflow through high-pressure atomizing nozzles, the sedimentation and stratification of the mixed powder caused by density differences are disrupted. The high-speed airflow through high-pressure atomizing nozzles causes the mixed powder to diffuse and mix through particle collisions. The mixed powder is fluidized and suspended in the cavity to form a circulating vortex, which improves the uniformity and consistency of the mixed powder distribution, reduces product performance fluctuations, controls product performance fluctuations within ±5%, improves product yield by 5%~10%, and thus reduces product production costs.

[0024] In addition, before the mixed powder is added to the airflow mixer, the exhaust gas cooling and recovery mechanism is activated.

[0025] Step S11: Prepare a phosphoric acid-acetone solution and spray the phosphoric acid-acetone solution onto the surface of the mixed powder through a high-pressure atomizing nozzle for phosphating treatment; Specifically, a phosphoric acid-acetone solution is prepared, with a mass ratio of phosphoric acid to acetone of 1:(70~80), and phosphoric acid accounting for 0.01%~0.5% of the mass of the mixed powder. The gas pressure is controlled at 0.3MPa~0.6MPa. The phosphoric acid-acetone solution, along with the gas, is periodically injected through a high-pressure atomizing nozzle to generate a high-speed airflow with a flow rate of 80m / s~160m / s and a period of 10s~15s. A pulse valve is installed at the bottom of the chamber to set the gas pressure to 0.2MPa~0.6MPa. Mix for 10 minutes and let stand for 1h~1.5h.

[0026] It should be noted that by using high-pressure atomization and periodic spraying, combined with the mixing-static process of the pulse valve at the bottom of the cavity, the phosphoric acid-acetone solution is applied evenly and fully to the surface of the mixed powder to form a uniform and controllable phosphating layer.

[0027] Step S12: After the phosphating treatment is completed, bake at the first preset temperature and then cool. The first preset temperature is 100℃~150℃, and the baking time is 1h~3h.

[0028] After phosphating, acetone (solvent) remains in the system. Higher temperatures can quickly evaporate the solvent, preventing residue from affecting subsequent processes. Furthermore, high temperatures can promote the depth of the phosphating reaction, making the phosphating layer on the surface of the mixed powder denser and more stable, enhancing the bonding force between the phosphating layer and the mixed powder, and providing a better surface activity and bonding basis for subsequent epoxy resin coating.

[0029] Step S13: Mix epoxy resin, acetone and silane coupling agent to prepare coupling solution, and spray the coupling solution onto the surface of the baked mixed powder through a high-pressure atomizing nozzle for coating treatment. Specifically, epoxy resin, acetone, and silane coupling agent are mixed to prepare a coupling solution. The mass ratio of epoxy resin, acetone, and silane coupling agent is (40~50):(210~220):1, and the epoxy resin accounts for 2%~5% of the mass of the mixed powder. The gas pressure in the airflow mixer is controlled at 0.4MPa~0.8MPa, so that the high-pressure atomizing nozzle periodically sprays to generate a high-speed airflow with a flow rate of 100m / s~200m / s and a cycle of 10s~15s. A pulse valve is installed at the bottom of the chamber with a gas pressure of 0.2MPa~0.6MPa, and premixing is performed for 10 minutes. The gas pressure in the airflow mixer is controlled at 0.3MPa~0.5MPa. The coupling solution and accompanying gas are periodically injected through a high-pressure atomizing nozzle to generate a high-speed airflow with a velocity of 70m / s~120m / s and a period of 10s~15s. A pulse valve is installed at the bottom of the chamber with a gas pressure of 0.2MPa~0.6MPa. Premixing takes 20min~40min.

[0030] It should be noted that the premixing stage utilizes the impact force of strong airflow to break up powder agglomerates, allowing the mixed powder to be fully dispersed within the cavity, creating a uniformly dispersed powder substrate for subsequent coating. Then, the coupling solution is uniformly atomized by the high-speed airflow and slowly and fully adheres to the surface of the pre-dispersed mixed powder. At the same time, the pulse valve at the bottom of the cavity continuously maintains the mixed powder in a suspended state, further ensuring the uniformity of contact between the mixed powder and the coupling solution, ultimately forming a continuous and uniform organic coating layer on the surface of the mixed powder.

[0031] Step S14: After the coating process is completed, granulation is performed, followed by baking at the second preset temperature and sieving to obtain an integrally molded soft magnetic composite powder for inductors.

[0032] Specifically, a 120-mesh sieve is installed on the granulator to granulate the mixed powder.

[0033] Furthermore, the second preset temperature is 40℃~80℃, and the baking time is 1h~3h. The coating layer is based on epoxy resin. The curing of epoxy resin is a stepwise polymerization process. Low temperature can achieve slow and uniform curing, avoiding excessive cross-linking, excessive internal stress, or even decomposition of epoxy resin caused by high temperature. At the same time, the interface modification effect of silane coupling agent can also be fully exerted at a mild temperature, further optimizing the interfacial compatibility and bonding strength of the inorganic powder-organic coating layer, ultimately making the coating layer more uniform and tougher, and ensuring the stability of the product's insulation, magnetic properties, and other indicators.

[0034] Preferably, the sieving process removes particles smaller than 80 mesh and larger than 200 mesh, and the resulting mixed powder is 80 to 200 mesh.

[0035] Accordingly, the present invention provides a soft magnetic composite powder for integrally molded inductors, wherein the soft magnetic composite powder for integrally molded inductors is prepared by the above-mentioned preparation method of the soft magnetic composite powder for integrally molded inductors.

[0036] In addition, such as Figure 1 As shown, this invention provides an apparatus for preparing a one-piece molded soft magnetic composite powder for inductors. The apparatus is used to perform the above-described method for preparing the one-piece molded soft magnetic composite powder for inductors. The apparatus includes: Airflow mixer, oven, granulator, vibrating screen; The airflow mixer is used to mix the powders and sequentially spray phosphoric acid-acetone solution and coupling solution for phosphating and coating treatment. The oven is used to bake the mixed powder after phosphating and granulation. The granulator is used to granulate the coated mixed powder; The vibrating screen is used to sieve the mixed powder after granulation and baking.

[0037] Furthermore, the airflow mixer includes a cavity 11, a waste gas cooling and recovery mechanism 5, and a powder collection box 9, all connected to the cavity 11. The side wall of the cavity 11 is provided with several high-pressure atomizing nozzles 1, the bottom of the cavity 11 is provided with several pulse valves 6, and the top of the cavity 11 is provided with a feeding port 2. Among them, the feeding port 2 is used to add the first aerosol powder, the second aerosol powder, and the water mist powder, and the high-pressure atomizing nozzle 1 is used to add the phosphoric acid-acetone solution, the coupling solution, and the high-pressure gas.

[0038] The top of the cavity 11 is connected to the waste gas cooling and recovery mechanism 5 through a dust filter 3 and a waste gas sealing collection cover 4, that is, it is connected through the waste gas discharge pipe 12. Among them, the waste gas cooling and recovery unit 5 is used to recover acetone, which reduces production costs, reduces environmental pollution, and strengthens the protection of the health of operators.

[0039] The cavity 11 is connected to the powder collection box 9 through the valve 7, that is, through the discharge port 8. The powder collection box 9 is provided with a powder discharge port 10 at the bottom. The exhaust gas cooling and recovery mechanism 5 is connected to the powder collection box 9 via another dust filter 3 and an exhaust gas sealing collection cover 4.

[0040] It should be noted that after the coating process is completed, the pulse valve 6 is closed, the valve 7 is opened, the coated mixed powder is blown into the powder collection box 9, the airflow mixer is closed, the powder outlet 10 is opened, and the coated mixed powder is poured into the granulator for granulation.

[0041] The following is a description using specific embodiments.

[0042] Example 1 The first embodiment of the present invention provides a method for preparing a soft magnetic composite powder for integrally molded inductors, the preparation method comprising: steps S10 to S14.

[0043] Step S10: Mix the first aerosol powder, the second aerosol powder, and the water mist powder in an airflow mixer to obtain a mixed powder. The particle size of the first aerosol powder is larger than the particle size of the water mist powder, which is larger than the particle size of the second aerosol powder. The first aerosol powder, the second aerosol powder, and the water mist powder are all Fe-Si-Cr alloy powders.

[0044] Furthermore, the mass ratio of the first aerosol powder, the second aerosol powder, and the water mist powder is 1:1:1, the D50 of the first aerosol powder is 20μm~23μm, the D50 of the water mist powder is 10μm~12μm, and the D50 of the second aerosol powder is 6μm~8μm.

[0045] Furthermore, the mixing process of the airflow mixer specifically includes: setting the gas pressure to 0.6 MPa, so that the high-pressure atomizing nozzle periodically sprays to generate a high-speed airflow with a flow rate of 150 m / s and a cycle of 13 s; First aerosol powder, second aerosol powder, and water mist powder are added into the feeding port of the cavity. A pulse valve is installed at the bottom of the cavity with a gas pressure of 0.4 MPa. Mix for 30 minutes.

[0046] In addition, before the mixed powder is added to the airflow mixer, the exhaust gas cooling and recovery mechanism is activated.

[0047] Step S11: Prepare a phosphoric acid-acetone solution and spray the phosphoric acid-acetone solution onto the surface of the mixed powder through a high-pressure atomizing nozzle for phosphating treatment; Specifically, a phosphoric acid-acetone solution is prepared, with a mass ratio of phosphoric acid to acetone of 1:75, and phosphoric acid accounting for 0.2% of the mass of the mixed powder. The gas pressure is controlled at 0.45 MPa. The phosphoric acid-acetone solution, along with the gas, is periodically injected through a high-pressure atomizing nozzle to generate a high-speed airflow with a flow rate of 110 m / s and a period of 13 s. A pulse valve is installed at the bottom of the chamber, with a gas pressure of 0.4 MPa. Mix for 10 minutes and let stand for 1.3 hours.

[0048] Step S12: After the phosphating treatment is completed, bake at the first preset temperature and then cool. The first preset temperature is 120℃, and the baking time is 2 hours.

[0049] Step S13: Mix epoxy resin, acetone and silane coupling agent to prepare coupling solution, and spray the coupling solution onto the surface of the baked mixed powder through a high-pressure atomizing nozzle for coating treatment. Specifically, epoxy resin, acetone, and silane coupling agent are mixed to prepare a coupling solution. The mass ratio of epoxy resin, acetone, and silane coupling agent is 45.7:214.3:1, and the epoxy resin accounts for 3.2% of the mass of the mixed powder. The gas pressure in the airflow mixer is controlled at 0.6 MPa, so that the high-pressure atomizing nozzle periodically sprays to generate a high-speed airflow with a flow rate of 150 m / s and a cycle of 13 s. A pulse valve is installed at the bottom of the chamber with a gas pressure of 0.4 MPa, and premixing is performed for 10 min. The gas pressure in the airflow mixer is controlled at 0.4 MPa. The coupling solution and accompanying gas are periodically injected through a high-pressure atomizing nozzle to generate a high-speed airflow with a flow rate of 90 m / s and a cycle of 13 s. A pulse valve is installed at the bottom of the chamber with a gas pressure of 0.4 MPa. Premixing takes 30 minutes.

[0050] Step S14: After the coating process is completed, granulation is performed, followed by baking at the second preset temperature and sieving to obtain an integrally molded soft magnetic composite powder for inductors.

[0051] Specifically, a 120-mesh sieve is installed on the granulator to granulate the mixed powder.

[0052] Furthermore, the second preset temperature is 60°C, and the baking time is 2 hours.

[0053] Preferably, the mixed powder is sieved to obtain a mesh size of 80-200.

[0054] Comparative Example 1 The first comparative example of this invention provides a method for preparing a soft magnetic composite powder for integrally molded inductors. The difference between the preparation method of the soft magnetic composite powder for integrally molded inductors in this comparative example and the preparation method of the soft magnetic composite powder for integrally molded inductors in the first embodiment is as follows: Only aerosol powder is used, and the D50 of the aerosol powder is 10μm~12μm.

[0055] Comparative Example 2 The second comparative example of this invention provides a method for preparing a soft magnetic composite powder for integrally molded inductors. The difference between the preparation method of the soft magnetic composite powder for integrally molded inductors in this comparative example and the preparation method of the soft magnetic composite powder for integrally molded inductors in the first embodiment is as follows: Only the second aerosol powder is used.

[0056] Comparative Example 3 The third comparative example of this invention provides a method for preparing a soft magnetic composite powder for integrally molded inductors. The difference between the preparation method of the soft magnetic composite powder for integrally molded inductors in this comparative example and the preparation method of the soft magnetic composite powder for integrally molded inductors in the first embodiment is as follows: Only the first aerosol powder is used.

[0057] Comparative Example 4 The fourth comparative example of this invention provides a method for preparing a soft magnetic composite powder for integrally molded inductors. The difference between the preparation method of the soft magnetic composite powder for integrally molded inductors in this comparative example and the preparation method of the soft magnetic composite powder for integrally molded inductors in the first embodiment is as follows: Only water mist powder is used, and the D50 of the water mist powder is 20μm~23μm.

[0058] Comparative Example 5 The fifth comparative example of this invention provides a method for preparing a soft magnetic composite powder for integrally molded inductors. The difference between the preparation method of the soft magnetic composite powder for integrally molded inductors in this comparative example and the preparation method of the soft magnetic composite powder for integrally molded inductors in the first embodiment is as follows: Only water mist powder is used, with two types of water mist powder having a D50 of 20μm~23μm and 6μm~8μm, in a mass ratio of 1:1.

[0059] Comparative Example 6 The sixth comparative example of this invention provides a method for preparing a soft magnetic composite powder for integrally molded inductors. The difference between the preparation method of the soft magnetic composite powder for integrally molded inductors in this comparative example and the preparation method of the soft magnetic composite powder for integrally molded inductors in the first embodiment is as follows: Using only water mist powder and second aerosol powder, the D50 of the water mist powder is 20μm~23μm.

[0060] Comparative Example 7 The seventh comparative example of this invention provides a method for preparing a soft magnetic composite powder for integrally molded inductors. The difference between the preparation method of the soft magnetic composite powder for integrally molded inductors in this comparative example and the preparation method of the soft magnetic composite powder for integrally molded inductors in the first embodiment is as follows: Using only water mist powder and first aerosol powder, the D50 of the water mist powder is 6μm~8μm.

[0061] Comparative Example 8 The eighth comparative example of this invention provides a method for preparing a soft magnetic composite powder for integrally molded inductors. The difference between the preparation method of the soft magnetic composite powder for integrally molded inductors in this comparative example and the preparation method of the soft magnetic composite powder for integrally molded inductors in the first embodiment is as follows: The D50 of the first aerosol powder is 20μm~23μm, the D50 of the water mist powder is 6μm~8μm, and the D50 of the second aerosol powder is 10μm~12μm.

[0062] Comparative Example 9 The ninth comparative example of this invention provides a method for preparing a soft magnetic composite powder for integrally molded inductors. The difference between the preparation method of the soft magnetic composite powder for integrally molded inductors in this comparative example and the preparation method of the soft magnetic composite powder for integrally molded inductors in the first embodiment is as follows: The mass ratio of the first aerosol powder, the second aerosol powder, and the water mist powder is 2:3:5.

[0063] Comparative Example 10 The tenth comparative example of this invention provides a method for preparing a soft magnetic composite powder for integrally molded inductors. The difference between the preparation method of the soft magnetic composite powder for integrally molded inductors in this comparative example and the preparation method of the soft magnetic composite powder for integrally molded inductors in the first embodiment is as follows: The mass ratio of the first aerosol powder, the second aerosol powder, and the water mist powder is 1:3:6.

[0064] Comparative Example 11 The eleventh comparative example of this invention provides a method for preparing a soft magnetic composite powder for integrally molded inductors. The difference between the preparation method of the soft magnetic composite powder for integrally molded inductors in this comparative example and the preparation method of the soft magnetic composite powder for integrally molded inductors in the first embodiment is as follows: Replace the airflow mixer with a planetary mixer.

[0065] Comparative Example 12 The twelfth comparative example of this invention provides a method for preparing a soft magnetic composite powder for integrally molded inductors. The difference between the preparation method of the soft magnetic composite powder for integrally molded inductors in this comparative example and the preparation method of the soft magnetic composite powder for integrally molded inductors in the first embodiment is as follows: Replace the airflow mixer with a plowshare mixer.

[0066] Comparative Example 13 The thirteenth comparative example of this invention provides a method for preparing a soft magnetic composite powder for integrally molded inductors. The difference between the preparation method of the soft magnetic composite powder for integrally molded inductors in this comparative example and the preparation method of the soft magnetic composite powder for integrally molded inductors in the first embodiment is as follows: The gas pressure in the gas mixer is set to 0.2 MPa when the coupling solution is added.

[0067] Please refer to the table below, which shows the performance test results of the integrally molded soft magnetic composite powder for inductors prepared under different embodiments and comparative examples.

[0068] The integrally molded inductor was pressed with a 127 magnetic ring using soft magnetic composite powder, and the performance of the finished powder was tested. The integrally molded inductor was also pressed with a 252010-1R0 integrally molded inductor using soft magnetic composite powder, and the inductor performance was tested. Saturation current Isat30: The current when the inductance drops to approximately 70% of its initial value (i.e., a 30% decrease), reflecting the component's anti-saturation capability under high current. The higher the value, the better the anti-saturation performance. Loss: Tested under two conditions (100kHz / 100mT, 1MHz / 20mT), reflecting the energy loss of the magnetic component during operation; the lower the value, the higher the energy efficiency.

[0069] Table 1:

[0070] As shown in Table 1, the three powder blends of the present invention improve the magnetic permeability and saturation magnetic induction intensity of the product and reduce losses.

[0071] Table 2:

[0072] Among them, Q value: quality factor, the core indicator for measuring the energy loss of inductor; inductance value at saturation current @ 4.3A: the inductance value when the saturation current @ 4.3A is reached; and inductance reduction rate Isat: the percentage by which the inductance value drops back to its initial value when the saturation current @ 4.3A is reached.

[0073] As shown in Table 2, the airflow mixer used in this invention mixes the powder. Compared with the powder produced by traditional mixing equipment, the powder produced by the airflow mixer in this invention has more stable performance, with performance fluctuation within ±5%. The airflow mixer used in this invention can effectively improve product yield and reduce product production costs.

[0074] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0076] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method for preparing a one-piece molded soft magnetic composite powder for inductors, characterized in that, The preparation method includes: The first aerosol powder, the second aerosol powder, and the water mist powder are mixed in an airflow mixer to obtain a mixed powder, wherein the particle size of the first aerosol powder is larger than the particle size of the water mist powder, which is larger than the particle size of the second aerosol powder. Prepare a phosphoric acid-acetone solution, and spray the phosphoric acid-acetone solution onto the surface of the mixed powder through a high-pressure atomizing nozzle for phosphating treatment; After the phosphating process is completed, bake at the first preset temperature and then cool. Epoxy resin, acetone, and silane coupling agent are mixed to prepare a coupling solution. The coupling solution is then sprayed onto the surface of the baked mixed powder through a high-pressure atomizing nozzle for coating treatment. After the coating process is completed, the material is granulated, baked at the second preset temperature, and sieved to obtain a one-piece molded soft magnetic composite powder for inductors.

2. The method for preparing the integrally molded soft magnetic composite powder for inductors according to claim 1, characterized in that, The first aerosol powder, the second aerosol powder, and the water mist powder all include one or more of the following: Fe-Ni-Mo alloy powder, Fe-Ni alloy powder, Fe-Co alloy powder, Fe-Si alloy powder, Fe-Si-Al alloy powder, Fe-Si-Cr alloy powder, Fe-based amorphous alloy powder, Ni-based amorphous alloy powder, Co-based amorphous alloy powder, and Fe-based nanocrystalline powder.

3. The method for preparing the integrally molded soft magnetic composite powder for inductors according to claim 2, characterized in that, The mass ratio of the first aerosol powder, the second aerosol powder, and the water mist powder is 1:(0.5~2):(0.5~2), the D50 of the first aerosol powder is 20μm~23μm, the D50 of the water mist powder is 10μm~12μm, and the D50 of the second aerosol powder is 6μm~8μm.

4. The method for preparing the integrally molded soft magnetic composite powder for inductors according to claim 1, characterized in that, The step of mixing the first aerosol powder, the second aerosol powder, and the water mist powder in an airflow mixer to obtain a mixed powder specifically includes: The gas pressure is set to 0.4MPa~0.8MPa, so that the high-pressure atomizing nozzle periodically sprays to generate a high-speed airflow with a flow rate of 100m / s~200m / s and a period of 10s~15s. First aerosol powder, second aerosol powder, and water mist powder are added into the feeding port of the cavity. A pulse valve is installed at the bottom of the cavity with a gas pressure of 0.2MPa~0.6MPa. Mix for 10min~40min.

5. The method for preparing the integrally molded soft magnetic composite powder for inductors according to claim 1, characterized in that, The steps of preparing a phosphoric acid-acetone solution and spraying the phosphoric acid-acetone solution onto the surface of the mixed powder through a high-pressure atomizing nozzle for phosphating treatment specifically include: Prepare a phosphoric acid-acetone solution with a phosphoric acid to acetone mass ratio of 1:(70~80) and phosphoric acid accounting for 0.01%~0.5% of the mass of the mixed powder. The gas pressure is controlled at 0.3MPa~0.6MPa. The phosphoric acid-acetone solution, along with the gas, is periodically injected through a high-pressure atomizing nozzle to generate a high-speed airflow with a flow rate of 80m / s~160m / s and a period of 10s~15s. A pulse valve is installed at the bottom of the chamber to set the gas pressure to 0.2MPa~0.6MPa. Mix for 10 minutes and let stand for 1h~1.5h.

6. The method for preparing the integrally molded soft magnetic composite powder for inductors according to claim 1, characterized in that, The steps of mixing epoxy resin, acetone, and silane coupling agent to prepare a coupling solution, and spraying the coupling solution onto the surface of the baked mixed powder through a high-pressure atomizing nozzle for coating treatment, specifically include: Epoxy resin, acetone, and silane coupling agent are mixed to prepare a coupling solution. The mass ratio of epoxy resin, acetone, and silane coupling agent is (40~50):(210~220):1, and the epoxy resin accounts for 2%~5% of the mass of the mixed powder. The gas pressure in the airflow mixer is controlled at 0.4MPa~0.8MPa, so that the high-pressure atomizing nozzle periodically sprays to generate a high-speed airflow with a flow rate of 100m / s~200m / s and a cycle of 10s~15s. A pulse valve is installed at the bottom of the chamber with a gas pressure of 0.2MPa~0.6MPa, and premixing is performed for 10 minutes. The gas pressure in the airflow mixer is controlled at 0.3MPa~0.5MPa. The coupling solution and accompanying gas are periodically injected through a high-pressure atomizing nozzle to generate a high-speed airflow with a velocity of 70m / s~120m / s and a period of 10s~15s. A pulse valve is installed at the bottom of the chamber with a gas pressure of 0.2MPa~0.6MPa. Premixing takes 20min~40min.

7. The method for preparing the integrally molded soft magnetic composite powder for inductors according to claim 1, characterized in that, The first preset temperature is 100℃~150℃, and the baking time is 1h~3h. The second preset temperature is 40℃~80℃, and the baking time is 1h~3h.

8. A one-piece molded soft magnetic composite powder for inductors, characterized in that, The integrally molded soft magnetic composite powder for inductors is prepared by the preparation method of the integrally molded soft magnetic composite powder for inductors according to any one of claims 1 to 7.

9. An apparatus for preparing a one-piece molded soft magnetic composite powder for inductors, characterized in that, The apparatus for preparing the integrally molded soft magnetic composite powder for inductors is used to perform the preparation method of the integrally molded soft magnetic composite powder for inductors according to any one of claims 1 to 7, wherein the apparatus comprises: Airflow mixer, oven, granulator, vibrating screen; The airflow mixer is used to mix the powders and sequentially spray phosphoric acid-acetone solution and coupling solution for phosphating and coating treatment. The oven is used to bake the mixed powder after phosphating and granulation. The granulator is used to granulate the coated mixed powder; The vibrating screen is used to sieve the mixed powder after granulation and baking.

10. The apparatus for preparing integrally molded soft magnetic composite powder for inductors according to claim 9, characterized in that, The airflow mixer includes a cavity, a waste gas cooling and recovery mechanism, and a powder collection box, all connected to the cavity. The sidewall of the cavity is provided with several high-pressure atomizing nozzles, the bottom of the cavity is provided with several pulse valves, and the top of the cavity is provided with a feeding port; The top of the cavity is connected to the waste gas cooling and recovery mechanism through a dust filter and a waste gas sealing collection hood; The cavity is connected to the powder collection box via a valve, and the powder collection box has a powder outlet at the bottom; The exhaust gas cooling and recovery mechanism is connected to the powder collection box via another dust filter and an exhaust gas sealing collection hood.

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