CN-122000160-A - High-reliability metal soft magnetic composite material, preparation method thereof and inductor

CN122000160ACN 122000160 ACN122000160 ACN 122000160ACN-122000160-A

Abstract

The invention relates to a high-reliability metal soft magnetic composite material, a preparation method thereof and an inductor, which comprise a metal soft magnetic alloy powder core, a phosphate passivation layer, an inorganic insulation coating layer and an organic bonding coating layer, wherein the phosphate passivation layer, the inorganic insulation coating layer and the organic bonding coating layer are sequentially coated on the surface of the metal soft magnetic alloy powder core from inside to outside, the phosphate passivation layer is a compact phosphate passivation film generated by in-situ reaction between weak acid and the surface of the metal soft magnetic alloy powder core, the thickness is 50nm to 200nm, the inorganic insulation coating layer is a silicon dioxide insulation film bridged by using a silane coupling agent and generated on the surface of the phosphate passivation layer in situ, the thickness is 100nm to 300nm, the organic bonding coating layer is an organic coating film formed by curing a high-molecular adhesive and is coated on the outer surface of the inorganic insulation coating layer, and the thickness is 200nm to 500nm. The invention has the beneficial effects of avoiding the problems of uneven coating and poor batch stability of the conventional stirring process and solving the industry pain points of mould pressing cracking and swelling.

Inventors

YANG PEIPEI
TIAN LIN
XIAO CHI
CHEN YUANLIN
LI JIANGYAN

Assignees

深圳市艺感科技股份有限公司

Dates

Publication Date: 20260508
Application Date: 20260317

Claims (10)

1. The high-reliability metal soft magnetic composite material is characterized by comprising a metal soft magnetic alloy powder core, a phosphate passivation layer, an inorganic insulating coating layer and an organic bonding coating layer, wherein the phosphate passivation layer, the inorganic insulating coating layer and the organic bonding coating layer are sequentially coated on the surface of the metal soft magnetic alloy powder core from inside to outside; the phosphate passivation layer is a compact phosphate passivation film generated by in-situ reaction of weak acid and the surface of the metal soft magnetic alloy powder core, and the thickness is 50nm to 200nm; The inorganic insulating coating layer is a silicon dioxide insulating film which takes a silane coupling agent as a bridge connection and is generated on the surface of the phosphate passivation layer in situ, and the thickness is 100nm to 300nm; The organic bonding coating layer is an organic coating film formed by curing the high polymer adhesive and is coated on the outer surface of the inorganic insulating coating layer, and the thickness is 200nm to 500nm.
2. The high-reliability metal soft magnetic composite material according to claim 1, wherein the metal soft magnetic alloy powder core is iron-based soft magnetic alloy powder, and is a composite powder of one or more selected from iron-nickel soft magnetic powder, iron-nickel-molybdenum soft magnetic powder, iron-silicon-aluminum soft magnetic powder, iron-silicon-soft magnetic powder and iron-silicon-chromium soft magnetic powder, and the particle size of the metal soft magnetic alloy powder core is 2 μm to 50 μm, and the metal soft magnetic alloy powder core is sieved by a 300-500 mesh sieve.
3. The high-reliability metal soft magnetic composite material according to claim 1, wherein the raw material of the phosphate passivation layer is passivation solution, the passivation solution comprises weak acid and solvent, the weak acid is selected from one or more of phosphoric acid, monoammonium phosphate, sodium ammonium hydrogen phosphate, oxalic acid and nitrate, the solvent is selected from one or more of distilled water, ethyl acetate, acetone, ethanol, isopropanol and paraxylene, and the dosage of the weak acid is 0.1wt% to 1.0wt% of the mass of the metal soft magnetic alloy powder core.
4. The high-reliability metal soft magnetic composite material according to claim 1, wherein the raw materials of the inorganic insulating coating layer comprise a silane coupling agent and tetraethoxysilane, the silane coupling agent is one or more of gamma-aminopropyl triethoxysilane, gamma-glycidol ether oxypropyl trimethoxysilane and vinyl triethoxysilane, the dosage is 0.2-12 wt% of the mass of the metal soft magnetic alloy powder core, and the dosage of the tetraethoxysilane is 0.1-1.0 wt% of the mass of the metal soft magnetic alloy powder core.
5. The high-reliability metal soft magnetic composite material according to claim 1, wherein the raw materials of the organic bonding coating layer comprise an adhesive and an organic solvent, the adhesive is one or more selected from epoxy resin, organic silicone resin, polyamide resin, polypropylene silicone resin, ethyl orthosilicate, polyvinyl alcohol and biphenyl type phenol epoxy resin, the amount is 1.0 to 4.0 weight percent of the mass of the powder after inorganic coating, and the amount is one or more selected from ethyl acetate, acetone, ethanol, isopropanol and p-xylene, and the amount is 8 to 15 weight percent of the mass of the powder after inorganic coating.
6. A method for preparing a high-reliability metal soft magnetic composite material, which is suitable for the high-reliability metal soft magnetic composite material according to any one of claims 1 to 5, and is characterized by comprising the following steps: S1, screening metal soft magnetic alloy powder with preset particle size, and weighing and standby according to preset mass after screening; s2, preparing passivation solution, adding the passivation solution and metal soft magnetic alloy powder into an ultrasonic stirring tank, completing passivation reaction under the condition of low-temperature ultrasonic, and cleaning, drying and sieving after the reaction is finished to obtain passivation powder; S3, preparing a silane coupling agent solution, adding the silane coupling agent solution, tetraethoxysilane and passivation powder into an ultrasonic stirring tank, completing an in-situ coating reaction under the room-temperature ultrasonic condition, and drying and sieving after the reaction is finished to obtain inorganic coating powder; and S4, uniformly mixing the organic solvent and the adhesive, adding the inorganic coating powder into the mixed solution, stirring and mixing, and then sieving and drying to obtain the granulating powder.
7. The method for preparing a highly reliable metal soft magnetic composite material according to claim 6, wherein in S2, the solvent of the passivation solution is freshly distilled water at 5 ℃ to 10 ℃, the passivation reaction temperature is 5 ℃ to 18 ℃, the cyclic vibration time of the ultrasonic dispersion system is 8min to 12min, the drying temperature after passivation is 60 ℃ to 90 ℃, the drying time is 20min to 40min, and the powder after drying is sieved by a 300-500 mesh sieve.
8. The method for preparing a high-reliability metal soft magnetic composite material according to claim 6, wherein in S3, the in-situ coating reaction temperature is 20 ℃ to 25 ℃, the cyclic vibration time of the ultrasonic dispersion system is 8min to 12min, the post-reaction drying temperature is 60 ℃ to 90 ℃, the drying time is 10min to 30min, and the dried powder is sieved by a 300-500-mesh sieve.
9. The method for preparing a high-reliability metal soft magnetic composite material according to claim 6, wherein in S4, the drying temperature is 50-80 ℃ after organic coating, the drying time is 30-60 min, and the granulated powder is obtained by sieving with a 40-200 mesh sieve.
10. An inductor suitable for the preparation method of the high-reliability metal soft magnetic composite material of claim 6, which is characterized by comprising a magnetic core body and a metal coil embedded in the magnetic core body, and the magnetic core body and the metal coil are subjected to compression molding and heat treatment in sequence; In the compression molding step, adding a lubricant into the granulated powder, wherein the lubricant is one or more of graphite, hexagonal boron nitride, zinc stearate and microcrystalline wax, the dosage is 0.1-0.9 wt% of the mass of the granulated powder, and the compression molding pressure is 11-13T; The heat treatment step is carried out in an N 2 atmosphere of minus 0.09MPa, specifically, 40min is raised to 150 ℃ from normal temperature, 40min is raised to 300 ℃ and is kept at 40min, 40min is raised to 450 ℃ and is kept at 40min, 40min is raised to 600 ℃, 40min is kept at 40min, 700 ℃ to 720 ℃ and is kept at 60min, wherein the temperature raising rate is 1.5 ℃ to 6 ℃ per min.

Description

High-reliability metal soft magnetic composite material, preparation method thereof and inductor Technical Field The invention relates to the technical field of soft magnetic composite materials, in particular to a high-reliability metal soft magnetic composite material, a preparation method thereof and an inductor. Background The integrated power inductor is widely applied to high-power circuits such as industrial control mainboards, display cards, notebook computers, vehicle-mounted equipment, communication equipment and medical equipment, and the core performance index of the integrated power inductor is directly determined by the magnetic parameters, insulating performance and structural stability of the soft magnetic composite material, so that the performance optimization of the soft magnetic composite material is a core key for improving the comprehensive performance of the integrated inductor. In the prior art, the proportion of the passivation solution and the reaction process are difficult to accurately control, so that uneven coating and exceeding roughness of the powder surface are caused, the magnetic performance and the insulating performance of the powder core are directly deteriorated, and meanwhile, the insulating performance and the formability cannot be considered in a single-layer coating structure. Disclosure of Invention Aiming at the defects of the prior art, the application provides the high-reliability metal soft magnetic composite material, the preparation method and the inductor thereof, the powder agglomeration is broken through by the cavitation effect and the dispersion effect of ultrasonic waves, the coating layer uniformly and compactly grows on the surface of single particles, the problems of uneven coating and poor batch stability of the conventional stirring process are avoided, the material resistivity and the pressure resistance are improved by the design of a three-layer core-shell composite structure, the temperature resistance is ensured by an inorganic layer, the formability is improved by an organic layer, and the industry pain points of mould pressing cracking and swelling are solved. The technical scheme of the invention is that the high-reliability metal soft magnetic composite material comprises a metal soft magnetic alloy powder core, and a phosphate passivation layer, an inorganic insulating coating layer and an organic bonding coating layer which are sequentially coated on the surface of the metal soft magnetic alloy powder core from inside to outside; the phosphate passivation layer is a compact phosphate passivation film generated by in-situ reaction of weak acid and the surface of the metal soft magnetic alloy powder core, and the thickness is 50nm to 200nm; The inorganic insulating coating layer is a silicon dioxide insulating film which takes a silane coupling agent as a bridge connection and is generated on the surface of the phosphate passivation layer in situ, and the thickness is 100nm to 300nm; The organic bonding coating layer is an organic coating film formed by curing the high polymer adhesive and is coated on the outer surface of the inorganic insulating coating layer, and the thickness is 200nm to 500nm. As a preferable scheme of the invention, the metal soft magnetic alloy powder core is iron-based soft magnetic alloy powder, and is selected from one or more of iron-nickel soft magnetic powder, iron-nickel-molybdenum soft magnetic powder, iron-silicon-aluminum soft magnetic powder, iron-silicon soft magnetic powder and iron-silicon-chromium soft magnetic powder, and the particle size of the metal soft magnetic alloy powder core is 2 mu m to 50 mu m, and the metal soft magnetic alloy powder core is sieved by a 300-500-mesh sieve. As a preferable scheme of the invention, the raw material of the phosphate passivation layer is passivation solution, the passivation solution comprises weak acid and solvent, the weak acid is selected from one or more of phosphoric acid, monoammonium phosphate, sodium hydrogen phosphate, oxalic acid and nitrate, the solvent is selected from one or more of distilled water, ethyl acetate, acetone, ethanol, isopropanol and paraxylene, and the dosage of the weak acid is 0.1wt% to 1.0wt% of the mass of the metal soft magnetic alloy powder core. As a preferable scheme of the invention, the raw materials of the inorganic insulating coating layer comprise a silane coupling agent and tetraethoxysilane, wherein the silane coupling agent is one or more of gamma-aminopropyl triethoxysilane, gamma-glycidol ether oxypropyl trimethoxysilane and vinyl triethoxysilane, the dosage is 0.2 to 12 weight percent of the mass of the metal soft magnetic alloy powder core, and the dosage of the tetraethoxysilane is 0.1 to 1.0 weight percent of the mass of the metal soft magnetic alloy powder core. As a preferable scheme of the invention, the raw materials of the organic bonding coating layer comprise an adhesive and an organic solvent, wherein