CN112927915B

CN112927915B - Inductance element and manufacturing method thereof

Info

Publication number: CN112927915B
Application number: CN202110098432.0A
Authority: CN
Inventors: 柯昕
Original assignee: Zhejiang Santi Technology Co ltd
Current assignee: Zhejiang Santi Technology Co ltd
Priority date: 2021-01-25
Filing date: 2021-01-25
Publication date: 2023-07-21
Anticipated expiration: 2041-01-25
Also published as: CN112927915A

Abstract

The invention provides an inductance element and a manufacturing method thereof, comprising a lead and a magnet, wherein both ends of the lead are exposed outside the magnet, an inductance is immersed in resin, the resin is sucked into the magnet under the capillary action and fills up the pores in the magnet, the resin in the pores is cured through high-temperature baking, and the cured resin bonds magnetic powder for pressing together, so that the mechanical strength of the inductance can be greatly improved, and the inductance quantity is not reduced or the inductance power consumption is not increased.

Description

Inductance element and manufacturing method thereof

Technical Field

The present invention relates to the field of manufacturing electrical components, and in particular, to a method for manufacturing an inductance component.

Background

With the development of the market and the advancement of electronic technology, the inductive element is continuously developed to the targets of high current, high frequency, small size and low power consumption. The frequency and the magnitude of ripple current flowing through the inductor are also continuously increased, so that the heating value of the inductor is increased, higher requirements are put on the magnet loss and the conductor loss of the inductor, and heat energy generated by the coil and the magnetic core in the inductor is also required to be rapidly and effectively dissipated, because the heating value is more, the temperature of the operation of the inductor is increased and the efficiency of the inductor is reduced due to the continuous accumulation, and even the whole element is possibly burnt out. Particularly, the development of the 5G communication and automotive electronics fields has made more stringent specifications and requirements for the size and characteristics of the inductive elements.

Some inductance elements can be installed on the automobile, and in the driving process of the automobile, the automobile body can always vibrate with different frequencies and amplitudes, and particularly when the automobile body passes through a hollow uneven road section, the automobile body can shake violently. In the conventional patch inductor, the inductor magnet and the pins are fixed only by using adhesive, and when the inductor is shaken or vibrated, the adhesive for fixing the inductor magnet and the pins may be loosened, so that the inductor magnet or the pins are peeled off, and the inductor element is disabled.

The existing large-current inductor with equivalent turns less than or equal to 1 is mainly assembled by an assembly process, matching tolerance is needed for assembly between a magnet and a conductor, glue adhered between magnetic cores has certain thickness, the gaps are not improved on DCR and saturation current of the inductor, waste of inductance space is caused, an inductor with smaller volume of the same performance or an inductor with better volume performance cannot be manufactured, and reliability risk of loosening of the adhesive is also caused.

Patent CN107749340a discloses a high-reliability high-current molded inductor and a manufacturing method, so that the middle part of a wire is arranged in a magnet to be integrated with the magnet, and the gap between the magnet and the conductor is reduced, but the method does not carry out resin impregnation treatment on the inductor, a binder and a release agent added in the magnetic powder insulation step contain oxyhydrogen groups of carbon, and can be decomposed into gas to leave the inside of the inductor in the high-temperature annealing process, and a large number of tiny pores are left in the inside of the magnet due to the decomposition of the binder and the release agent, so that the mechanical strength of the inductor is poor.

Disclosure of Invention

An aspect of the present invention relates to a method of manufacturing an inductance element, including the steps of:

s1c, mixing the iron-based magnetic powder with a binder and a lubricant according to a certain proportion to obtain magnetic powder for pressing;

s2c, placing a wire in the die;

s3c, filling the magnetic powder for pressing into a die, exposing two ends of the wire to the magnetic powder for pressing, pressing to integrate the wire and the magnetic powder for pressing, and then demolding to obtain an integrated inductance pressed compact;

s4c, performing high-temperature heat treatment on the inductance compact to manufacture an inductance element;

s5c, immersing the inductance element after the high-temperature heat treatment into resin for 0.2-3 h, preferably 0.5-1 h, taking out the inductance element, cleaning the resin remained on the surface by using an organic solvent, and putting the inductance element into an oven for baking and curing for 1-3 h under the atmosphere of protective gas, wherein the step is preferably carried out under the condition of vacuumizing < 1 Pa.

The binder and the release agent in the magnetic powder for pressing contain carbon-hydroxyl groups, and are decomposed into gas to leave the inside of the inductor in the high-temperature annealing process, and a large number of tiny pores are left in the magnet after the binder and the release agent are decomposed. The inductor is immersed in the resin, and the resin is sucked into the magnet under the action of capillary action to fill the pores inside the magnet. The resin in the pores is cured through high-temperature baking, the cured resin bonds the iron-based magnetic powder together, so that the mechanical strength of the inductor can be greatly improved, the inductance value is not reduced or the inductance power consumption is increased, different types of resin can obtain different bending strength and tensile strength combinations, and the types of resin can be selected according to the use scene of the inductor.

Further, the method also comprises the following steps:

s1a, carrying out surface film forming reaction on the S1c iron-based magnetic powder, and generating a composite insulating layer of ferrite and silicon dioxide on the surface.

When the iron-based magnetic powder is extruded by large pressing pressure, plastic deformation can occur to generate dislocation and slip of grain boundaries, so that the internal stress of the magnet is increased to influence the rotation of magnetic domains, the magnetic performance is deteriorated, and the pressing stress is removed by high-temperature annealing heat treatment to obtain better magnetic performance.

Compared with the traditional method of coating the iron-based magnetic powder by using an organic adhesive such as silicone, the method can bear higher temperature, so that the magnet can select higher annealing temperature, the inductance, the power consumption, the high temperature resistance and the direct current voltage resistance of the inductance element are improved, the annealing temperature can be selected according to different performance requirements of the inductance, and the inductance element can be stably served in a higher temperature working state.

Further, the surface film forming reaction in the step S1a is to add the iron-based magnetic powder into an aqueous solution of at least one of phosphoric acid, phosphate, chromic acid, chromate, silicate, sulfate and borate and a silane coupling agent to perform the surface film forming reaction.

The ferrite and silicon dioxide composite insulating layer is generated by surface reaction, and can bear high temperature of 960 ℃ at most.

Further, the method also comprises the following steps:

s2a, carrying out surface insulation treatment on the wire in the step S2c by using nano oxides, and forming a nano composite insulating layer on the surface of the wire, wherein the nano oxides are uniformly distributed on the nano composite insulating layer.

Conventional wires are insulated by wrapping the surfaces of copper wires with resin paint, the resin paint can only be used under the low-temperature condition below 200 ℃, carbonization can occur after high-temperature annealing to lose insulation efficacy, volatile matters during carbonization can infiltrate among magnetic powder particles for compression, the insulativity among the powder is reduced, and the inductance power consumption is increased and the inductance is reduced. According to the invention, the nano composite insulating layer is formed on the surface of the lead through surface insulating treatment by using the nano oxide, the nano oxide can bear higher annealing temperature without characteristic change, and when the thickness of the nano composite insulating layer is thin, the direct-current voltage resistance of the inductor can be obviously improved under the condition of slightly reducing the inductance.

Further, the wire in the step S2a is a copper wire, and the surface insulation treatment is to immerse the copper wire in a weight ratio of silane coupling agent to diluent of 1: 2-10, preferably 1:4-6, taking out the residual liquid on the drained surface, and then putting the residual liquid into an aqueous suspension of nano silicon dioxide, nano aluminum oxide and sodium silicate, preferably nano silicon dioxide in a weight ratio of: nano aluminum oxide: sodium silicate=2 to 5:2 to 5: soaking in 90-96 aqueous suspension for 1-3min, taking out, putting into an oven at 60-100 ℃, preferably 70-80 ℃ for baking, and forming a nano composite insulating layer on the surface of the wire, wherein nano oxides are uniformly distributed on the nano composite insulating layer.

The nano silicon dioxide is adsorbed on the surface of the copper wire, nano aluminum oxide is added to enable the nano silicon dioxide to be fully dispersed in the suspension, so that the nano silicon dioxide is more uniformly adsorbed on the surface of the copper wire, a nano composite insulating layer is formed on the surface of the lead, the formed nano oxide can bear the annealing temperature of 700 ℃ without changing the characteristics, and when the thickness of the nano composite insulating layer is thin, the direct-current voltage resistance of the inductor can be obviously improved under the condition of slightly reducing the inductance.

Further, the high-temperature heat treatment in the step S4c comprises two stages of preheating and annealing, wherein the preheating temperature is 100-300 ℃, the holding time is more than or equal to 30min, the annealing temperature is 500-960 ℃, preferably 650-800 ℃, more preferably 700-750 ℃, the holding time is 10-40 min, preferably 20-30 min, and at least one of nitrogen, hydrogen and argon is used as a protective atmosphere, or the vacuumizing is less than 0.1Pa, preferably less than 0.02Pa.

The iron-based magnetic powder is subjected to large pressing pressure extrusion, plastic deformation can occur to generate dislocation and slip of grain boundaries, so that the internal stress of the magnet is increased to influence the rotation of magnetic domains, the magnetic performance is deteriorated, the pressing stress can be eliminated through annealing heat treatment, the higher the annealing temperature is, the better the stress eliminating effect is, when the annealing temperature exceeds the Curie temperature of the magnetic powder, the pressing stress can be almost completely eliminated, and the best magnetic performance can be obtained. When the iron-based magnetic powder is coated by using an organic adhesive such as silicone resin, the silicone resin can be converted into a glass state under the condition of low-temperature baking to realize insulating coating of the magnetic powder, but the decomposition temperature point of the hydrocarbon groups of the silicone resin is far lower than the Curie temperature of most of the iron-based magnetic powder. Optimal properties of the magnetic powder cannot be achieved using annealing conditions well below the curie temperature, and the magnetic powder is decomposed into gas which escapes out of the magnet when annealed at a high temperature exceeding 500 ℃, and the glassy coating is destroyed, resulting in deterioration of magnetic properties.

The invention carries out surface film forming reaction on the iron-based magnetic powder, generates a composite insulating layer of ferrite and silicon dioxide on the surface, can bear the high temperature of 960 ℃ at most and can already cover most of Curie temperature of the iron-based magnetic powder, therefore, the invention selects annealing temperature of 500-960 ℃, preferably 650-800 ℃ and more preferably 700-750 ℃ so as to improve the performance of the inductance element.

Further, the method also comprises the following steps:

s2b, pressing the magnetic powder for pressing in the step S1c into a prefabricated bottom blank, wherein the prefabricated bottom blank is provided with a limiting wire groove, and the copper wire processed in the step S2a is placed in the limiting wire groove according to the designed direction;

and in the step S2c, placing the assembled prefabricated base blank and copper wires at the bottom of the die.

The spacing metallic channel supports and positions the wire, prevents to lead to the skew of wire because the atress is uneven in the suppression in-process.

Further, the method also comprises the following steps:

and S6c, covering and protecting the lead wire of the exposed magnet part by using a high-temperature adhesive tape, or protecting the exposed lead wire by using a release agent.

S7c, preheating the inductor to 130-160 ℃, spraying at least one of 0.02-0.1mm thick alkyd paint, epoxy paint, novolac and epoxy polyester phenolic paint on the surface of the inductor, and baking and curing at 130-160 ℃ after spraying.

The iron-based magnetic powder has large specific surface area and high surface activity, and the metal interface is easy to generate chemical or electrochemical multiphase reaction, so that the metal is converted into an oxidation state to generate rust reaction, and the appearance of the product is influenced. According to the invention, a layer of paint film is attached to the surface of the metal to seal the contact between the metal substrate and air and harmful substances, so that the aim of rust prevention is fulfilled. Meanwhile, the paint layer can improve the insulation resistance between the copper wire and the magnetic powder, so that the anti-rust purpose is achieved, and meanwhile, the direct-current voltage resistance can be improved.

Further, the method also comprises the following steps:

and S8c, bending two ends of the copper wire exposed outside the magnet to enable the two ends of the copper wire to be attached to the surface of the magnet to form electrode pins, mechanically polishing or etching the surfaces of the electrode pins by laser, and carrying out tin dipping or tin plating treatment on the pins after removing the nano composite insulating layer on the surfaces of the copper wire.

Further, the method also comprises the following steps:

s8d, punching and bending the tinned copper sheet, prefabricating electrode pins, assembling the two ends of the copper wire exposed outside the magnet with the electrode pins, and welding the two ends of the copper wire with the electrode pins.

When the lead is thicker, the electrode pin is prefabricated because the magnet is easy to damage in the turnover process, the electrode pin and the lead of the magnet part exposed out of the inductor are assembled, the positioning is carried out through the fit clearance between the electrode pin and the lead and the fixture, and the mechanical and electrical connection is carried out through welding technologies such as brazing or laser welding.

Further, a plurality of limiting wire grooves are formed in the prefabricated substrate in the step S2b, and copper wires with the corresponding number processed in the step S2a are placed in the limiting wire grooves according to the designed direction.

Multiple wires can be provided to prepare the multiphase inductive element according to the regulatory requirements of a two-phase or three-phase power supply applied to the power inductor.

Another aspect of the invention relates to an inductance element, comprising a wire and a magnet, wherein both ends of the wire are exposed outside the magnet, and the inductance element is coated with a layer of resin.

The resin bonds the iron-based magnetic powder together, so that the mechanical strength of the inductor can be greatly improved, the inductance value is not reduced or the inductance power consumption is increased, different types of resin can obtain different bending strength and tensile strength combinations, and the types of resin can be selected according to the use scene of the inductor.

Further, the magnet comprises iron-based magnetic powder particles coated with a composite insulating layer of ferrite and silicon dioxide, and the inductance element can maintain the efficiency at 500-960 ℃, preferably 700-900 ℃.

The composite insulating layer of ferrous salt and silicon dioxide can bear the highest high temperature of 960 ℃, so that the inductance element can be stably in service under the working state of higher temperature.

Further, the surface of the wire is coated with a nano composite insulating layer, and nano oxides are uniformly distributed on the nano composite insulating layer.

The nano oxide can bear 700 ℃ high temperature without changing the characteristics, so that the inductance element can be stably in service under a higher temperature working state, and when the thickness of the nano composite insulating layer is thin, the direct-current voltage resistance of the inductance can be obviously improved under the condition of not influencing the inductance.

Further, a wire slot extending from one end of the magnet to the other end of the magnet is arranged in the magnet, the wire is inserted in the wire slot, and two ends of the wire are exposed out of the wire slot; the two ends of the lead are connected with electrode pins, the edges of the top surfaces of the two ends of the magnet are provided with accommodating grooves for accommodating the electrode pins, and the width of the accommodating grooves is equal to that of the magnet; the electrode pins are formed by bending two ends of a wire, which are exposed out of the magnet, of the wire, the two ends of the wire are symmetrically attached to the surface of the magnet, and the width of the two end parts of the wire is larger than that of the middle part of the wire.

The width of the accommodating groove is set to be equal to the width of the magnet, and the accommodating groove can be directly grooved from one side surface to the other side surface of the magnet during processing, so that on one hand, the groove is less difficult to process; on the other hand, the problem that the conventional slotting mode is easy to cause microcracks on the magnet is solved. The integrated blanking-formed I-shaped lead can increase the welding area of the welding pad, reduce the contact resistance and increase the welding strength. Because no post-processing procedures such as edging and welding exist, the method has high reliability and is suitable for severe scenes such as vehicle-mounted scenes.

Further, a wire slot extending from one end of the magnet to the other end of the magnet is arranged in the magnet, the wire is inserted in the wire slot, and two ends of the wire are exposed out of the wire slot; the two ends of the lead are connected with electrode pins, the edges of the top surfaces of the two ends of the magnet are provided with accommodating grooves for accommodating the electrode pins, and the width of the accommodating grooves is equal to that of the magnet; the electrode pins are formed by bending the middle part of the tinned wire, and the electrode pins are bent to form a first folding pin and a second folding pin; the first folding leg of the electrode pin is provided with a pin fixing groove, two ends of a wire can be inserted into the pin fixing groove on the first folding leg of the electrode pin and welded in the pin fixing groove through brazing or laser, and the second folding leg of the electrode pin can be tightly attached in the accommodating groove of the magnet; the width of the second folding leg is larger than that of the lead, and the width of the second folding leg is smaller than or equal to that of the magnet.

The width of the accommodating groove is set to be equal to the width of the magnet, so that the problem that the right angle position of the traditional inner right angle wire groove is subjected to processing stress during pressing and microcracks are easy to generate is solved. When the lead is thicker, the electrode pin is prefabricated because the magnet is easy to damage in the turnover process, the electrode pin and the lead of the magnet part exposed out of the inductor are assembled, the positioning is carried out through the fit clearance between the electrode pin and the lead and the fixture, and the mechanical and electrical connection is carried out through welding technologies such as brazing or laser welding. The second folding leg with larger width can increase the welding area of the welding pad, reduce the contact resistance and increase the welding strength. The length of the accommodating groove can be reduced by increasing the width of the accommodating groove, so that the magnetic path sectional area of the inductor is increased, the inductance and saturation current of the inductor can be improved to a limited extent, and the power consumption of the inductor is reduced.

Further, the magnet consists of a prefabricated bottom blank and a top blank; the lead is placed on the prefabricated base blank, and two ends of the lead are exposed out of the prefabricated base blank; the top surface of the prefabricated bottom blank is provided with a limiting wire groove parallel to the length direction of the prefabricated bottom blank, the middle part of the wire is arranged in the limiting wire groove, and two sides of the wire are propped against two side walls of the limiting wire groove; the preform bottom can be mated with the top to compress the wire.

Drawings

FIG. 1 is an explanatory view of example 13 of the present invention.

FIG. 2 is an explanatory view of example 14 of the present invention.

FIG. 3 is an explanatory view of example 15 of the present invention.

FIG. 4 is an exploded view of example 15 of the present invention.

Fig. 5 is an explanatory view of the magnet of the present invention.

In the figure: magnet 1, accommodating groove 11, prefabricated bottom blank 12, limit wire groove 121 and top blank 13; a wire 2, a wire end 21; electrode pin 3, first pin 31, pin fixing groove 311, second pin 32.

Detailed Description

Various aspects of the invention will be described in detail below, but the invention is not limited to these specific embodiments. Modifications and adaptations of the invention will occur to those skilled in the art and are intended to be within the scope of the invention based upon the following disclosure.

The inventor has developed a manufacturing method of an inductance element through extensive and intensive research, and the inductance element manufactured by the method has the advantages of high inductance, low power consumption, high temperature resistance, high direct current voltage resistance, high bending strength, high tensile strength and rust prevention.

Surface film forming reaction of magnetic powder

The iron-based magnetic powder in the prior art comprises iron-nickel powder, iron-silicon powder, carbonyl iron powder, iron-silicon aluminum powder, iron-silicon-chromium powder, amorphous powder and nanocrystalline powder, wherein the inventor selects common FeNi50 powder manufactured by gas atomization, takes FeNi50 powder which does not perform surface film forming reaction as a comparison group, takes FeNi50 powder which performs surface film forming reaction as an implementation group, and respectively manufactures inductance elements at annealing temperature 300 ℃, 400 ℃, 500 ℃, 600 ℃, 700 ℃, 800 ℃, 900 ℃, 960 ℃ and 1000 ℃ under the condition that other preparation processes are the same, and respectively measures inductance, power consumption and direct current voltage resistance of the inductance elements.

Comparison group

1. Preparation of magnetic powder for pressing

The raw powder is prepared by mixing FeNi50 powder produced by gas atomization according to the weight ratio of +200 mesh 5%, -200 to +325 mesh 25%, -325 to +800 mesh 45% and the balance of-800 mesh powder. Mixing silicon resin and alcohol according to the weight ratio of 1:15 to prepare silicon resin solution, and mixing the raw powder and the silicon resin solution according to the weight ratio of 1: mixing 0.015, coating the raw powder with silicone resin to obtain secondary powder, screening granulated powder with the granularity of 80-200 meshes in the secondary powder, and adding a mixture of calcium stearate and zinc stearate with the weight ratio of 0.2% as a lubricant to obtain magnetic powder for compression;

2. Compression molding

Filling the pressing magnetic powder prepared in the first step into a 4x10x2mm die, and placing a copper wire with the thickness of 0.5x2.0x18mm in the die, wherein two ends of the copper wire are clamped in the die and exposed out of the pressing magnetic powder. Pressing with 1600MPa, maintaining the pressure for 0.5s, and finally demolding to obtain an inductance compact formed by integrating copper wires and magnetic powder for pressing;

3. high temperature heat treatment

The induction pressed compact is put into an atmosphere furnace for heat treatment, the heat treatment temperature is mainly divided into two main stages of preheating and annealing, the preheating temperature is 150 ℃ and the holding time is 80min, the main purpose is to avoid the cracking of a magnet caused by the rapid volatilization of a lubricant, the annealing temperature is 300 ℃, 400 ℃, 500 ℃, 600 ℃, 700 ℃, 800 ℃, 900 ℃, 960 ℃, 1000 ℃ and the holding time is 20min, the processing stress generated during pressing is eliminated, the magnetic permeability is improved, the magnetic loss is reduced, and pure nitrogen is used as a protective atmosphere.

Implementation group

1. Preparation of magnetic powder for pressing

The raw powder is prepared by mixing FeNi50 powder produced by gas atomization according to the weight ratio of +200 mesh 5%, -200 to +325 mesh 25%, -325 to +800 mesh 45% and the balance of-800 mesh powder. Adding the raw powder into phosphoric acid in a weight ratio of: silane coupling agent: water = 0.5:0.5:99 and the silane coupling agent, the reaction temperature is 100 ℃ and the reaction time is 0.5h. Mixing silicon resin and alcohol according to the weight ratio of 1:15 to prepare silicon resin solution, and mixing the raw powder and the silicon resin solution according to the weight ratio of 1:0.015, coating the raw powder with silicone resin to obtain secondary powder; screening granulated powder with the granularity of 80-200 meshes in secondary powder, and adding a mixture of calcium stearate and zinc stearate with the weight ratio of 0.2% as a lubricant to obtain magnetic powder for pressing;

2. Compression molding

3. high temperature heat treatment

Inductance of 100kHz/1V of the inductance element prepared in the comparison group and the implementation group was tested by using a 3255B LCR analyzer, power consumption of 500kHz/50mT was tested by using a SY8219 BH analyzer, direct current voltage resistance of the inductance was tested by using a 3153HIPOT tester (DC measuring range 50-200V), and the measurement results are shown in Table 1.

TABLE 1

The iron-based magnetic powder is subjected to large pressing pressure extrusion, plastic deformation can occur to generate dislocation and slip of grain boundaries, so that the internal stress of the magnet is increased to influence the rotation of magnetic domains, the magnetic performance is deteriorated, the pressing stress can be eliminated through annealing heat treatment, the higher the annealing temperature is, the better the stress eliminating effect is, when the annealing temperature exceeds the Curie temperature of the magnetic powder, the pressing stress can be almost completely eliminated, and the best magnetic performance can be obtained. When the metal powder is coated by the silicone resin, the silicone resin can be converted into a glass state under the low-temperature baking condition to realize insulating coating of the magnetic powder, but the decomposition temperature point of the hydrocarbon groups of the silicone resin is far lower than the Curie temperature of most iron-based magnetic powder. Optimal properties of the magnetic powder cannot be achieved using annealing conditions well below the curie temperature, and the magnetic powder is decomposed into gas which escapes out of the magnet when annealed at a high temperature exceeding 500 ℃, and the glassy coating is destroyed, resulting in deterioration of magnetic properties.

According to the invention, phosphoric acid and a silicon-based insulating agent are used for insulating the iron-based magnetic powder, the ferrous phosphate and silicon dioxide composite insulating layer generated by reaction can bear the high temperature of 960 ℃, when the annealing temperature reaches 1000 ℃, the insulating layer is destroyed, the loss of a magnet is severely increased, and the inductance performance is deteriorated. The curie temperature of most iron-based magnetic powders can already be covered at 960 c, so that optimal electromagnetic properties are obtained using the magnetic powder insulation method of the invention, and the preferred annealing temperature can be chosen according to the different performance requirements of the inductance.

Surface insulation treatment of wire

Based on the implementation of the group technology, the inventor selects an annealing temperature of 700 ℃ by integrating the optimal balance value of inductance and magnet loss and withstand voltage, and immerses pure copper wires into a silane coupling agent and alcohol in a weight ratio of 1:4, taking out the mixed solution of 4, draining the residual liquid on the surface, and immersing the mixed solution into nano silicon dioxide respectively: nano aluminum oxide: sodium silicate = 2:2: 96. 5:2: 93. 2:5: 93. 5:5:90 is soaked in the aqueous suspension for 1min, taken out and put into an oven at 80 ℃ to be baked to obtain insulated copper wires with different insulation degrees, so as to perform surface insulation treatment on the copper wires and form a nano composite insulation layer on the surfaces of the wires. The inductance which is not insulated by the copper wire is used as a comparison group 1, the copper wire insulated by the common resin paint is used as a comparison group 2, and the power consumption and the direct current voltage resistance of the inductance elements are respectively measured. The specific implementation steps are as follows:

1. preparation of magnetic powder for pressing

2. Copper wire surface insulation treatment

Immersing pure copper wires with the weight ratio of 0.5x2.0x18mm into a silane coupling agent to alcohol of 1:4, taking out the mixed solution of 4, draining the residual liquid on the surface, and immersing the mixed solution into nano silicon dioxide respectively: nano aluminum oxide: sodium silicate = 2:2: 96. 5:2: 93. 2:5: 93. 5:5:90 is soaked in the aqueous suspension for 1min, taken out and put into an oven at 80 ℃ to be baked to obtain an insulated copper wire;

3. compression molding

Filling the pressing magnetic powder prepared in the first step into a 4x10x2mm die, and placing the insulated copper wire obtained in the second step into the die, wherein two ends of the copper wire are clamped in the die and exposed out of the pressing magnetic powder. Pressing with 1600MPa, maintaining the pressure for 0.5s, and finally demolding to obtain an inductance compact formed by integrating copper wires and magnetic powder for pressing;

4. high temperature heat treatment

The induction pressed compact is placed into an atmosphere furnace for heat treatment, the heat treatment temperature is mainly divided into two main stages of preheating and annealing, the preheating temperature is 150 ℃, the holding time is 80min, the main purpose is to avoid cracking of a magnet caused by rapid volatilization of a lubricant, the annealing temperature is 700 ℃, the holding time is 20min, the processing stress generated during pressing is eliminated, the magnetic conductivity is improved, the magnetic loss is reduced, and pure nitrogen is used as a protective atmosphere.

5. Folding pin

Bending two ends of a wire exposed outside the magnet to enable two ends of the wire to be symmetrically attached to the surface of the magnet to form electrode pins, mechanically polishing or etching the surface of the electrode pins by laser, removing an insulating layer on the surface of the wire, and then carrying out tin dipping or tin plating on the pins to form the inductor.

Inductance of 100kHz/1V of the inductance element prepared in the comparison group and the implementation group was tested by using a 3255B LCR analyzer, power consumption of 500kHz/50mT was tested by using a SY8219 BH analyzer, direct current voltage resistance of the inductance was tested by using a 3153HIPOT tester (DC measuring range 50-200V), and the measurement results are shown in Table 2.

TABLE 2

Insulation formula ratio	inductance/nH	Power consumption/W	Withstand voltage/V
				Comparative group 1	100.5	0.22	62.1
Comparative group 2	84.2	0.31	63.9
				2∶2∶96	98.3	0.20	73.0
5∶2∶93	98.7	0.22	86.3
				2∶5∶93	93.9	0.23	76.8
5∶5∶90	90.1	0.25	87.2

Conventional copper wires are coated on the surfaces of the copper wires by using resin paint for insulation, the resin paint can only be used under the low-temperature condition of below 200 ℃, carbonization can occur after annealing at 700 ℃ to lose insulation efficacy, volatile matters during carbonization can permeate among magnetic powder particles, the insulativity among the powder is reduced, and the power consumption of the inductor is increased and the inductance is reduced. According to the invention, the nano silicon dioxide is adsorbed on the surface of the copper wire, and the nano aluminum oxide is added to enable the nano silicon dioxide to be fully dispersed in the suspension, so that the nano silicon dioxide is more uniformly adsorbed on the surface of the copper wire, a nano composite insulating layer is formed on the surface of the lead, the nano oxide can bear 700 ℃ annealing without characteristic change, and when the thickness of the nano composite insulating layer is thin, the direct-current voltage resistance of the inductor can be obviously improved under the condition of slightly reducing the inductance.

Impregnating resin

On the basis of the implementation process, the inventor selects nano silicon dioxide, nano aluminum oxide, sodium silicate=5:2:93 aqueous suspension to perform surface insulation treatment on copper wires, respectively immerses the heat-treated inductors in epoxy resin, phenolic resin, furan resin, alkyd resin and silicone resin for 1h, takes out the inductors, washes out resin remained on the surface by using an organic solvent, puts the inductors into an oven for baking and curing at 180 ℃ for 3h, prepares the inductance elements by using nitrogen as protective atmosphere, and respectively measures the inductance, power consumption, direct current voltage resistance, bending strength and tensile strength of the inductance elements. The specific implementation steps are as follows:

1. preparation of magnetic powder for pressing

The raw powder is prepared by mixing FeNi50 powder produced by gas atomization according to the weight ratio of +200 mesh 5%, -200 to +325 mesh 25%, -325 to +800 mesh 45% and the balance of-800 mesh powder. Adding the raw powder into an aqueous solution of phosphoric acid and a silane coupling agent in a weight ratio of phosphoric acid to the silane coupling agent to water=0.5:0.5:99 for surface film forming reaction, wherein the reaction temperature is 100 ℃, and the reaction time is 0.5h. Mixing silicon resin and alcohol according to the weight ratio of 1:15 to prepare silicon resin solution, and mixing the raw powder and the silicon resin solution according to the weight ratio of 1:0.015, coating the raw powder with silicone resin to obtain secondary powder; screening granulated powder with the granularity of 80-200 meshes in secondary powder, and adding a mixture of calcium stearate and zinc stearate with the weight ratio of 0.2% as a lubricant to obtain magnetic powder for pressing;

2. Copper wire surface insulation treatment

Immersing pure copper wires with the weight ratio of 0.5x2.0x18mm into a silane coupling agent to alcohol of 1:4, taking out the mixed solution of 4, draining the residual liquid on the surface, and immersing into nano silicon dioxide: nano aluminum oxide: sodium silicate = 5:2:93, soaking the copper wire in the aqueous suspension for 1min, taking out the copper wire, and putting the copper wire into an oven at 80 ℃ to be baked to obtain insulated copper wires with different insulation degrees;

3. compression molding

4. high temperature heat treatment

5. Impregnating resin

Immersing the heat-treated inductor in epoxy resin, phenolic resin, furan resin, alkyd resin and silicone resin for 1h respectively, taking out the inductor, cleaning the resin remained on the surface by using an organic solvent, and putting the inductor into an oven for baking and curing for 3h at 180 ℃ under the protection of nitrogen.

6. Folding pin

The inductance of the inductance element 100kHz/1V prepared by the comparison group and the implementation group is tested by using a 3255B LCR analyzer, the power consumption of 500kHz/50mT is tested by using a SY8219 BH analyzer, the direct current voltage resistance of the inductance is tested by using a 3153HIPOT tester (DC measuring range is 50-200V), the flexural strength and tensile strength of samples prepared by different types of resins are tested by using an SD2000 universal material tester, and the measurement results are shown in Table 3.

TABLE 3 Table 3

The binder and the release agent in the magnetic powder for pressing contain carbon-hydroxyl groups, and are decomposed into gas to leave the inside of the inductor in the annealing process at 700 ℃, and a large number of tiny pores are left in the magnet due to the decomposition of the binder and the release agent. The inductor is immersed in the resin, and the resin is sucked into the magnet under the action of capillary action to fill the pores inside the magnet. The resin in the pores is cured through high-temperature baking, the cured resin bonds the magnetic powder for pressing together, so that the mechanical strength of the inductor can be greatly improved, the inductance value is not reduced or the inductance power consumption is increased, different types of resin can obtain different bending strength and tensile strength combinations, and the types of resin can be selected according to the use scene of the inductor.

Surface spray coating

When the requirements on the antirust performance of the inductor are high in the use environment or the working voltage of the inductor is high, the risk that the requirement cannot be met exists in the integrated bare inductor made of the iron-based magnetic powder is possibly caused, the inventor selects epoxy resin as impregnating resin on the basis of the implementation process, the withstand voltage level and the antirust level of the inductor are improved through spraying a coating on the surface of the inductor, the inductor is preheated to 150 ℃, at least one of a layer of 0.02-0.1mm thick alkyd paint, epoxy paint, novolac paint and epoxy polyester novolac paint is sprayed on the surface of the inductor, baking and curing are carried out at 150 ℃ after spraying, an inductor element is manufactured, and the direct current voltage resistance of the inductor element is measured and a neutral salt spray test is carried out. The specific implementation steps are as follows:

1. preparation of magnetic powder for pressing

2. Copper wire surface insulation treatment

3. compression molding

4. high temperature heat treatment

5. Impregnating resin

Immersing the heat-treated inductor in epoxy resin for 1h, taking out the inductor, cleaning the resin remained on the surface by using an organic solvent, putting the inductor into an oven, baking and curing for 3h at 180 ℃, wherein the protective atmosphere is nitrogen.

6. Protective wire

The exposed conductor of the magnet part is covered and protected by a high-temperature adhesive tape, or the exposed conductor is soaked in a parting agent for protection.

7. Spray coating

Preheating the inductor to 150 ℃, spraying at least one of a layer of alkyd paint, epoxy paint, novolac and epoxy polyester phenolic paint with the thickness of 0.02-0.1mm on the surface of the inductor, and baking and curing at 150 ℃ after spraying.

8. Cleaning wire

And D, removing the protective wire in the step seven by using a high-temperature adhesive tape or a release agent, and thoroughly cleaning attachments on the surface of the wire.

9. Folding pin

The inductor was tested for DC voltage resistance using a 3153HIPOT tester (DC range 50-200V), placed in a salt spray apparatus containing 5.+ -. 0.5% sodium chloride and pH 6.5-7.2 at 35.+ -. 3 ℃ for neutral salt spray test, and observed for surface corrosion area over 8 hours, and the measurement results are shown in Table 4.

TABLE 4 Table 4

Example 1:

1. preparation of magnetic powder for pressing

2. Copper wire surface insulation treatment

Immersing pure copper wires with the weight ratio of 0.5x2.0x18mm into a silane coupling agent to alcohol of 1:4, taking out the mixed solution of 4, draining the residual liquid on the surface, and immersing into nano silicon dioxide: nano aluminum oxide: weight ratio of sodium silicate = 5:2:93, soaking the copper wire in the aqueous suspension for 1min, taking out the copper wire, and putting the copper wire into an oven at 80 ℃ to be baked to obtain insulated copper wires with different insulation degrees;

3. compression molding

4. high temperature heat treatment

5. Impregnating resin

6. Folding pin

Example 2:

1. preparation of magnetic powder for pressing

The raw powder is prepared by mixing FeNi50 powder produced by gas atomization according to the weight ratio of +200 mesh 5%, -200 to +325 mesh 25%, -325 to +800 mesh 45% and the balance of-800 mesh powder. Adding chromic acid, silane coupling agent, water=0.5: 1.5: and (3) carrying out surface film forming reaction on the chromic acid of 98 and the aqueous solution of the silane coupling agent, wherein the reaction temperature is 130 ℃, and the reaction time is 0.3h. Mixing silicon resin and alcohol according to the weight ratio of 1:15 to prepare silicon resin solution, and mixing the raw powder and the silicon resin solution according to the weight ratio of 1:0.015, coating the raw powder with silicone resin to obtain secondary powder; screening granulated powder with the granularity of 80-200 meshes in secondary powder, and adding a mixture of calcium stearate and zinc stearate with the weight ratio of 0.2% as a lubricant to obtain magnetic powder for pressing;

2. Copper wire surface insulation treatment

3. compression molding

4. high temperature heat treatment

5. Impregnating resin

6. Folding pin

Example 3:

1. preparation of magnetic powder for pressing

The raw powder is prepared by mixing FeNi50 powder produced by gas atomization according to the weight ratio of +200 mesh 5%, -200 to +325 mesh 25%, -325 to +800 mesh 45% and the balance of-800 mesh powder. Adding the raw powder into potassium silicate in a weight ratio: silane coupling agent: water = 1:1: and carrying out surface film forming reaction on the 98 potassium silicate and the aqueous solution of the silane coupling agent, wherein the reaction temperature is 110 ℃, and the reaction time is 1h. Mixing silicon resin and alcohol according to the weight ratio of 1:15 to prepare silicon resin solution, and mixing the raw powder and the silicon resin solution according to the weight ratio of 1:0.015, coating the raw powder with silicone resin to obtain secondary powder; screening granulated powder with the granularity of 80-200 meshes in secondary powder, and adding a mixture of calcium stearate and zinc stearate with the weight ratio of 0.2% as a lubricant to obtain magnetic powder for pressing;

2. Copper wire surface insulation treatment

3. compression molding

4. high temperature heat treatment

5. Impregnating resin

6. Folding pin

Example 4:

1. preparation of magnetic powder for pressing

The raw powder is prepared by mixing FeNi50 powder produced by gas atomization according to the weight ratio of +200 mesh 5%, -200 to +325 mesh 25%, -325 to +800 mesh 45% and the balance of-800 mesh powder. Adding zinc borate, a silane coupling agent, water=1: 2:97 zinc borate and a silane coupling agent, wherein the reaction temperature is 80 ℃ and the reaction time is 0.5h. Mixing silicon resin and alcohol according to the weight ratio of 1:15 to prepare silicon resin solution, and mixing the raw powder and the silicon resin solution according to the weight ratio of 1:0.015, coating the raw powder with silicone resin to obtain secondary powder; screening granulated powder with the granularity of 80-200 meshes in secondary powder, and adding a mixture of calcium stearate and zinc stearate with the weight ratio of 0.2% as a lubricant to obtain magnetic powder for pressing;

2. Copper wire surface insulation treatment

3. compression molding

4. high temperature heat treatment

5. Impregnating resin

6. Folding pin

Comparative example 1

1. Preparation of magnetic powder for pressing

2. Compression molding

3. high temperature heat treatment

The induction pressed compact is placed into an atmosphere furnace for heat treatment, the heat treatment temperature is mainly divided into two main stages of preheating and annealing, the preheating temperature is 150 ℃, the holding time is 80min, the main purpose is to avoid the cracking of a magnet caused by the rapid volatilization of a lubricant, the annealing temperature is 500 ℃ respectively, the holding time is 20min, the processing stress generated during pressing is eliminated, the magnetic conductivity is improved, and the magnetic loss is reduced.

Example 5:

1. preparation of magnetic powder for pressing

The FeSi9.6Al5.7 powder produced by gas atomization is mixed with the powder of +200 meshes 5%, -200 to +325 meshes 40%, -325 to +800 meshes 45% and the balance of-800 meshes according to the weight proportion to obtain the raw powder. Adding the raw powder into phosphoric acid in a weight ratio: silane coupling agent: water = 0.5:0.5:99 and the silane coupling agent, the reaction temperature is 100 ℃ and the reaction time is 0.5h. Mixing silicon resin and alcohol according to the weight ratio of 1:15 to prepare silicon resin solution, and mixing the raw powder and the silicon resin solution according to the weight ratio of 1:0.015, coating the raw powder with silicone resin to obtain secondary powder; screening granulated powder with the granularity of 80-200 meshes in secondary powder, and adding a mixture of calcium stearate and zinc stearate with the weight ratio of 0.2% as a lubricant to obtain magnetic powder for pressing;

2. Copper wire surface insulation treatment

3. compression molding

4. high temperature heat treatment

5. Impregnating resin

6. Folding pin

Example 6:

1. preparation of magnetic powder for pressing

The FeSi9.6Al5.7 powder produced by gas atomization is mixed with the powder of +200 meshes 5%, -200 to +325 meshes 40%, -325 to +800 meshes 45% and the balance of-800 meshes according to the weight proportion to obtain the raw powder. Adding raw powder into chromic acid in a weight ratio: silane coupling agent: water = 0.5:1.5: and (3) carrying out surface film forming reaction on the chromic acid of 98 and the aqueous solution of the silane coupling agent, wherein the reaction temperature is 130 ℃, and the reaction time is 0.3h. Mixing silicon resin and alcohol according to the weight ratio of 1:15 to prepare silicon resin solution, and mixing the raw powder and the silicon resin solution according to the weight ratio of 1:0.015, coating the raw powder with silicone resin to obtain secondary powder; screening granulated powder with the granularity of 80-200 meshes in secondary powder, and adding a mixture of calcium stearate and zinc stearate with the weight ratio of 0.2% as a lubricant to obtain magnetic powder for pressing;

2. Copper wire surface insulation treatment

3. compression molding

4. high temperature heat treatment

5. Impregnating resin

6. Folding pin

Example 7:

1. preparation of magnetic powder for pressing

The FeSi9.6Al5.7 powder produced by gas atomization is mixed with the powder of +200 meshes 5%, -200 to +325 meshes 40%, -325 to +800 meshes 45% and the balance of-800 meshes according to the weight proportion to obtain the raw powder. Adding the raw powder into potassium silicate in a weight ratio; a silane coupling agent; water = 1:1: and carrying out surface film forming reaction on the 98 potassium silicate and the aqueous solution of the silane coupling agent, wherein the reaction temperature is 110 ℃, and the reaction time is 1h. Mixing silicon resin and alcohol according to the weight ratio of 1:15 to prepare silicon resin solution, and mixing the raw powder and the silicon resin solution according to the weight ratio of 1:0.015, coating the raw powder with silicone resin to obtain secondary powder; screening granulated powder with the granularity of 80-200 meshes in secondary powder, and adding a mixture of calcium stearate and zinc stearate with the weight ratio of 0.2% as a lubricant to obtain magnetic powder for pressing;

2. Copper wire surface insulation treatment

3. compression molding

4. high temperature heat treatment

5. Impregnating resin

6. Folding pin

Example 8:

1. preparation of magnetic powder for pressing

The FeSi9.6Al5.7 powder produced by gas atomization is mixed with the powder of +200 meshes 5%, -200 to +325 meshes 40%, -325 to +800 meshes 45% and the balance of-800 meshes according to the weight proportion to obtain the raw powder. Adding the raw powder into zinc borate in a weight ratio: silane coupling agent: water = 1:2:97 zinc borate and a silane coupling agent, wherein the reaction temperature is 80 ℃ and the reaction time is 0.5h. Mixing silicon resin and alcohol according to the weight ratio of 1:15 to prepare silicon resin solution, and mixing the raw powder and the silicon resin solution according to the weight ratio of 1:0.015, coating the raw powder with silicone resin to obtain secondary powder; screening granulated powder with the granularity of 80-200 meshes in secondary powder, and adding a mixture of calcium stearate and zinc stearate with the weight ratio of 0.2% as a lubricant to obtain magnetic powder for pressing;

2. Copper wire surface insulation treatment

3. compression molding

4. high temperature heat treatment

5. Impregnating resin

6. Folding pin

Comparative example 2

1. Preparation of magnetic powder for pressing

The FeSi9.6Al5.7 powder produced by gas atomization is mixed with the powder of +200 meshes 5%, -200 to +325 meshes 40%, -325 to +800 meshes 45% and the balance of-800 meshes according to the weight proportion to obtain the raw powder. Mixing silicon resin and alcohol according to the weight ratio of 1:15 to prepare silicon resin solution, and mixing the raw powder and the silicon resin solution according to the weight ratio of 1: mixing 0.015, coating the raw powder with silicone resin to obtain secondary powder, screening granulated powder with the granularity of 80-200 meshes in the secondary powder, and adding a mixture of calcium stearate and zinc stearate with the weight ratio of 0.2% as a lubricant to obtain magnetic powder for compression;

2. Compression molding

3. high temperature heat treatment

Example 9:

1. preparation of magnetic powder for pressing

The FeSi5.5Cr5 powder produced by water atomization is mixed according to the weight ratio of-200 to +325 meshes of 10 percent, -325 to +800 meshes of 45 percent and the balance of-800 meshes of powder to prepare the raw powder. Adding the raw powder into the mixture in a weight ratio of 0.5:0.5:99, a silane coupling agent and an aqueous solution, wherein the reaction temperature is 100 ℃ and the reaction time is 0.5h. Mixing silicon resin and alcohol according to the weight ratio of 1:15 to prepare silicon resin solution, and mixing the raw powder and the silicon resin solution according to the weight ratio of 1:0.015, coating the raw powder with silicone resin to obtain secondary powder; screening granulated powder with the granularity of 80-200 meshes in secondary powder, and adding a mixture of calcium stearate and zinc stearate with the weight ratio of 0.2% as a lubricant to obtain magnetic powder for pressing;

2. Copper wire surface insulation treatment

3. compression molding

4. high temperature heat treatment

5. Impregnating resin

6. Folding pin

Example 10:

1. preparation of magnetic powder for pressing

The FeSi5.5Cr5 powder produced by water atomization is mixed according to the weight ratio of-200 to +325 meshes of 10 percent, -325 to +800 meshes of 45 percent and the balance of-800 meshes of powder to prepare the raw powder. Adding raw powder into chromic acid in a weight ratio: silane coupling agent: water = 0.5:1.5: and (3) carrying out surface film forming reaction on the chromic acid of 98 and the aqueous solution of the silane coupling agent, wherein the reaction temperature is 130 ℃, and the reaction time is 0.3h. Mixing silicon resin and alcohol according to the weight ratio of 1:15 to prepare silicon resin solution, and mixing the raw powder and the silicon resin solution according to the weight ratio of 1:0.015, coating the raw powder with silicone resin to obtain secondary powder; screening granulated powder with the granularity of 80-200 meshes in secondary powder, and adding a mixture of calcium stearate and zinc stearate with the weight ratio of 0.2% as a lubricant to obtain magnetic powder for pressing;

2. Copper wire surface insulation treatment

3. compression molding

4. high temperature heat treatment

5. Impregnating resin

6. Folding pin

Example 11:

1. preparation of magnetic powder for pressing

The FeSi5.5Cr5 powder produced by water atomization is mixed according to the weight ratio of-200 to +325 meshes of 10 percent, -325 to +800 meshes of 45 percent and the balance of-800 meshes of powder to prepare the raw powder. Adding the raw powder into potassium silicate in a weight ratio: silane coupling agent: water = 1:1: and carrying out surface film forming reaction on the 98 potassium silicate and the aqueous solution of the silane coupling agent, wherein the reaction temperature is 110 ℃, and the reaction time is 1h. Mixing silicon resin and alcohol according to the weight ratio of 1:15 to prepare silicon resin solution, and mixing the raw powder and the silicon resin solution according to the weight ratio of 1:0.015, coating the raw powder with silicone resin to obtain secondary powder; screening granulated powder with the granularity of 80-200 meshes in secondary powder, and adding a mixture of calcium stearate and zinc stearate with the weight ratio of 0.2% as a lubricant to obtain magnetic powder for pressing;

2. Copper wire surface insulation treatment

3. compression molding

4. high temperature heat treatment

5. Impregnating resin

6. Folding pin

Example 12:

1. preparation of magnetic powder for pressing

The FeSi5.5Cr5 powder produced by water atomization is mixed according to the weight ratio of-200 to +325 meshes of 10 percent, -325 to +800 meshes of 45 percent and the balance of-800 meshes of powder to prepare the raw powder. Adding the raw powder into zinc borate: silane coupling agent: water = 1:2:97 zinc borate and a silane coupling agent, wherein the reaction temperature is 80 ℃ and the reaction time is 0.5h. Mixing silicon resin and alcohol according to the weight ratio of 1:15 to prepare silicon resin solution, and mixing the raw powder and the silicon resin solution according to the weight ratio of 1:0.015, coating the raw powder with silicone resin to obtain secondary powder; screening granulated powder with the granularity of 80-200 meshes in secondary powder, and adding a mixture of calcium stearate and zinc stearate with the weight ratio of 0.2% as a lubricant to obtain magnetic powder for pressing;

2. Copper wire surface insulation treatment

3. compression molding

4. high temperature heat treatment

5. Impregnating resin

6. Folding pin

Comparative example 3

1. Preparation of magnetic powder for pressing

The FeSi5.5Cr5 powder produced by water atomization is mixed according to the weight ratio of-200 to +325 meshes of 10 percent, -325 to +800 meshes of 45 percent and the balance of-800 meshes of powder to prepare the raw powder. Mixing silicon resin and alcohol according to the weight ratio of 1:15 to prepare silicon resin solution, and mixing the raw powder and the silicon resin solution according to the weight ratio of 1: mixing 0.015, coating the raw powder with silicone resin to obtain secondary powder, screening granulated powder with the granularity of 80-200 meshes in the secondary powder, and adding a mixture of calcium stearate and zinc stearate with the weight ratio of 0.2% as a lubricant to obtain magnetic powder for compression;

2. Compression molding

3. high temperature heat treatment

The inventors tested the inductance, 60A superimposed inductance, magnetic permeability, magnet loss, direct current voltage resistance, compressive strength, flexural strength of the magnet loss inductance elements prepared in examples 1 to 12 and comparative examples 1 to 3, respectively, and the measurement results are shown in table 5.

TABLE 5

Example 13

As shown in fig. 1, an inductance element comprises a magnet 1 and a wire 2, wherein the magnet 1 comprises iron-based magnetic powder particles with different particle sizes, the iron-based magnetic powder particles are coated with a composite insulating layer of ferrous salt and silicon dioxide, the surface of the wire 2 is coated with an insulating protective layer, the surface of the wire 2 is coated with a nano composite insulating layer, nano oxides are uniformly distributed on the nano composite insulating layer, and a layer of resin is coated outside the inductance element. The magnet 1 is substantially rectangular parallelepiped, and the area of the long and high plane is smaller than the area of the wide plane of Yu Chang. A wire slot extending from one end of the magnet 1 to the other end of the magnet 1 is arranged in the magnet 1, and the wire slot is parallel to the length direction of the magnet 1. The wires 2 are inserted into the wire slots, the middle parts of the wires 2 are arranged in the wire slots, and two ends of the wires 2 are exposed out of two notches of the wire slots. The two ends of the lead wire 2 exposed outside the magnet 1 are bent, so that the two ends of the lead wire 2 are symmetrically attached to the top surface of the magnet 1, and electrode pins are formed. And (3) mechanically polishing or etching the surface of the electrode pin by laser, removing the insulating protective layer on the surface of the lead 2, and then carrying out tin dipping or tinning on the electrode pin. The top surface of the magnet 1 is provided with a receiving groove 11 for mounting the electrode pin, and both ends of the lead wire 2 are closely attached to the receiving groove 11 of the magnet 1.

Example 14

As shown in fig. 2, an inductance element comprises a magnet 1 and a wire 2, wherein the magnet 1 comprises iron-based magnetic powder particles with different particle sizes, the iron-based magnetic powder particles are coated with a composite insulating layer of ferrous salt and silicon dioxide, the surface of the wire 2 is coated with an insulating protective layer, the surface of the wire 2 is coated with a nano composite insulating layer, nano oxides are uniformly distributed on the nano composite insulating layer, and a layer of resin is coated outside the inductance element. The magnet 1 is substantially rectangular parallelepiped, and the area of the long and high plane is smaller than the area of the wide plane of Yu Chang. A wire slot extending from one end of the magnet 1 to the other end of the magnet 1 is arranged in the magnet 1, and the wire slot is parallel to the length direction of the magnet 1. The wires 2 are inserted into the wire slots, the middle parts of the wires 2 are arranged in the wire slots, and two ends of the wires 2 are exposed out of two notches of the wire slots. The two ends of the wire 2 exposed out of the notch of the wire inserting slot can be folded upwards to extend to the outer sides of the two ends of the magnet 1. The two ends of the lead 2 exposed outside the magnet 1 are bent, so that the two ends of the lead 2 are symmetrically attached to the top surface of the magnet 1 to form electrode pins, the surfaces of the electrode pins are mechanically polished or etched by laser, and after the insulating protective layer on the surfaces of the lead 2 is removed, the electrode pins are subjected to tin dipping or tin plating.

In the present embodiment, the width of the accommodation groove 11 of the top surface of the magnet 1 is equal to the width of the magnet 1. This embodiment is easier to machine than the prior art embodiments. While the magnet 1 is pressed, the accommodating groove 11 is also pressed and formed, and in the prior art, a processing stress exists in a right-angle position of a traditional inner right-angle wire groove during pressing, so that microcracks are easily generated in the magnet 1. Since the electrode pins are closely attached to the receiving grooves 11 of the magnet 1, in order to have a larger welding area when the inductor is welded to the circuit board, the width of the electrode pins at both end portions 21 of the wire 2 is larger than the width of the middle portion of the wire 2, and even the width of the electrode pins at both end portions 21 of the wire 2 may be equal to the width of the receiving grooves 11. The length of the accommodating groove 11 can be reduced by increasing the width of the accommodating groove 11, so that the magnetic path sectional area of the inductor is increased, the inductance and saturation current of the inductor can be improved to a limited extent, and the power consumption of the inductor is reduced.

Example 15

As shown in fig. 3, fig. 4 and fig. 5, an inductance element comprises a magnet 1 and a wire 2, wherein the magnet 1 comprises iron-based magnetic powder particles with different granularities, the iron-based magnetic powder particles are coated with a composite insulating layer of ferrite and silicon dioxide, the surface of the wire 2 is coated with a nano composite insulating layer, nano oxides are uniformly distributed on the nano composite insulating layer, and a layer of resin is coated outside the inductance element. The magnet 1 is substantially rectangular parallelepiped, and the area of the long and high plane is smaller than the area of the wide plane of Yu Chang. A wire slot extending from one end of the magnet 1 to the other end of the magnet 1 is arranged in the magnet 1, and the wire slot is parallel to the length direction of the magnet 1. The wires 2 are inserted into the wire slots, the middle parts of the wires 2 are arranged in the wire slots, and two ends of the wires 2 are exposed out of two notches of the wire slots.

As shown in fig. 5, the magnet 1 is composed of a preform 12 and a top preform 13, the preform 12 is provided with a limiting wire slot 121, that is, the wire slot described above, and the middle part of the wire 2 can be placed in the limiting wire slot 121, and both ends of the wire are exposed outside the preform 12. The limit wire groove 121 can clamp the wire 2. In order to eliminate this machining error, the upper end of the preform 12 and the lower end of the top preform 13 are placed on the same side for pressing when the preform 12 and the bottom preform are pressed. The top blank 13 may be formed by filling insulating magnetic powder in a pressing groove in which the preform base 12 and the wire 2 are placed and pressing the insulating magnetic powder at a high temperature. The top blank 13 formed by compression molding can be matched with the prefabricated bottom blank 12 to form the magnet 1; the top blank 13 may be pressed from insulating magnetic powder alone, then placed in a pressing tank, and pressed together with the preform 12 at high temperature to form the magnet 1.

In the embodiment of the present embodiment regarding the height of the two side walls of the limit wire groove 121, when the height of the two side walls of the limit wire groove 121 is smaller than the height of the wire 2, the bottom surface of the top blank 13 is provided with a limit supplement groove corresponding to the limit wire groove 121, so that the pre-bottom blank 12 and the top blank 13 can compress the wire 2; when the height of the two side walls of the limit wire groove 121 is equal to the height of the wire 2, the bottom surface of the top blank 13 is a plane; when the height of the two side walls of the limit wire groove 121 is larger than the height of the wire 2, the bottom surface of the top blank 13 is provided with limit groove filling blocks corresponding to the limit wire groove 121 on the prefabricated bottom blank 12, so that the prefabricated bottom blank 12 and the top blank 13 can press the wire 2.

As shown in fig. 5, the magnet 1 is formed by pressing a preform 12 and a top preform 13. When the thickness of the lead 2 is relatively thin, two ends of the lead 2 are integrally connected with the electrode pins, and the lead slots are exposed out of the two ends of the lead 2 and are turned over to the top surface of the magnet 1, so that the two ends of the lead 2 are symmetrically attached to the top surface of the magnet 1 to form the electrode pins; however, when the lead wire 2 is thicker, as shown in fig. 3, the electrode pin is prefabricated and assembled with the lead wire 2 of which the inductance is exposed out of the magnet 1 because the lead wire 2 is thicker in the folding process and the lamination structure of the magnet 1 is easily damaged.

In this embodiment, the tinned wire 2 is punched and bent to form an electrode pin to be connected, the wire 2 with the part of the inductor exposed out of the magnet 1 is assembled with the electrode pin, the positioning is performed through a fit gap between the wire 2 and the electrode pin, and the mechanical and electrical connection is performed through welding technologies such as brazing or laser welding. The top surface of the magnet 1 is provided with an accommodating groove 11 for installing electrode pins, and the middle part of the electrode pins is bent to form a first folding pin 31 and a second folding pin 32; the first folding leg 31 of the electrode pin is provided with a pin fixing groove 311, two ends of the lead 2 can be inserted into the pin fixing groove 311 on the first folding leg 31 of the electrode pin and soldered or laser welded in the pin fixing groove 311, and the second folding leg 32 of the electrode pin can be tightly attached in the accommodating groove 11 of the magnet 1. The width of the second folding leg 32 is larger than the width of the wire 2, and the width of the second folding leg 32 is smaller than or equal to the width of the magnet 1. The width of the second folding leg 32 is set to be larger, so that the inductance is welded on the circuit board to have larger welding area, and meanwhile, in order to ensure the close fit between the second folding leg 32 and the accommodating groove 11, the width of the second folding leg 32 should be smaller than or equal to the width of the magnet 1.

Claims

1. A method of manufacturing an inductance component, comprising the steps of:

s1a, adding iron-based magnetic powder into an aqueous solution of at least one of phosphoric acid, phosphate, chromic acid, chromate, silicate, sulfate and borate and a silane coupling agent to perform surface film forming reaction, and generating a composite insulating layer of ferrous salt and silicon dioxide on the surface;

s2a, carrying out surface insulation treatment on a wire by using nano oxide, wherein the surface insulation treatment is to immerse the wire in a mixed solution of a silane coupling agent and a diluent, take out and drain residual liquid on the surface, put into an aqueous suspension of nano silicon dioxide, nano aluminum oxide and sodium silicate, take out and bake;

s2c, placing the wire processed in the step S2a in a die;

s4c, carrying out high-temperature heat treatment on the inductance compact to obtain an inductance element, wherein the high-temperature heat treatment temperature comprises two stages of preheating and annealing, and the annealing temperature is 500-960 ℃;

S5c, immersing the inductance element after the high-temperature heat treatment into resin for 0.2-3 h, taking out the inductance element, cleaning the resin remained on the surface by using an organic solvent, performing baking and curing for 1-3 h under the condition of protective gas atmosphere or vacuum pumping less than 1 Pa.

2. The method of manufacturing an inductance component according to claim 1, wherein the inductance component after the high-temperature heat treatment is immersed in the resin for 0.5 to 1h in step S5 c.

3. The method of manufacturing an inductance component according to claim 1, wherein the conductive wire in the step S2a is a copper wire, and the surface insulation treatment is to dip the copper wire into a silane coupling agent and a diluent in a weight ratio of 1: 2-10, mixing the liquid for 2-10 min, taking out the residual liquid on the surface, putting the water-based suspension of nano silicon dioxide, nano aluminum oxide and sodium silicate into the mixed liquid, taking out the mixed liquid, putting the mixed liquid into the water-based suspension at 60-100 ℃, and forming a nano composite insulating layer on the surface of the wire, wherein nano oxides are uniformly distributed on the nano composite insulating layer.

4. The method of manufacturing an inductance component according to claim 3, wherein the wire in the step S2a is a copper wire, the surface insulation treatment is to dip the copper wire into a mixed solution of a silane coupling agent and a diluent in a weight ratio of 1:4-6 for 2-5 min, take out the drained surface residual liquid, and put into nano silicon dioxide in a weight ratio of: nano aluminum oxide: sodium silicate=2 to 5:2 to 5: soaking in 90-96 aqueous suspension for 1-3 min, taking out, and baking in a 70-80 ℃ oven to form a nano composite insulating layer on the surface of the wire, wherein nano oxides are uniformly distributed on the nano composite insulating layer.

5. The method of manufacturing an inductor device according to any one of claims 1 to 4, wherein the step S4c of high temperature heat treatment comprises two stages of preheating and annealing, the preheating temperature is 100 to 300 ℃, the holding time is not less than 30 minutes, the annealing temperature is 500 to 960 ℃, the holding time is 20 to 30 minutes, and at least one of nitrogen, hydrogen and argon is used as a protective atmosphere, or vacuum pumping is less than 0.1Pa.

6. The method of manufacturing an inductor device according to any one of claims 1 to 4, wherein the step S4c of high temperature heat treatment comprises two stages of preheating and annealing, the preheating temperature is 100 to 300 ℃, the holding time is not less than 30 minutes, the annealing temperature is 650 to 800 ℃, the holding time is 20 to 30 minutes, and at least one of nitrogen, hydrogen and argon is used as a protective atmosphere, or vacuum pumping is less than 0.1Pa.

7. The method of manufacturing an inductor device according to any one of claims 1 to 4, wherein the step S4c of high temperature heat treatment comprises two stages of preheating and annealing, the preheating temperature is 100 to 300 ℃, the holding time is equal to or longer than 30 minutes, the annealing temperature is 700 to 750 ℃, the holding time is 20 to 30 minutes, and at least one of nitrogen, hydrogen and argon is used as a protective atmosphere, or vacuum pumping is less than 0.02Pa.

8. The method of manufacturing an inductance component according to claim 5, further comprising the steps of:

9. The method of manufacturing an inductance component according to claim 5, further comprising the steps of:

s6c, covering and protecting the exposed lead wire of the magnet part by using a high-temperature adhesive tape, or protecting the exposed lead wire by using a dipping parting agent;

s7c, preheating the inductor to 130-160 ℃, spraying at least one of 0.02-0.1 mm thick alkyd paint, epoxy paint, novolac and epoxy polyester phenolic paint on the surface of the inductor, and baking and curing at 130-160 ℃ after spraying.

10. The method of manufacturing an inductance component according to claim 5, further comprising the steps of:

11. The method of manufacturing an inductance component according to claim 5, further comprising the steps of:

12. The method of manufacturing an inductor according to claim 8, wherein a plurality of limiting grooves are formed in the prefabricated base in step S2b, and a corresponding number of copper wires processed in step S2a are placed in the limiting grooves in a designed direction.

13. An inductance component comprising a lead wire and a magnet manufactured by the method for manufacturing an inductance component according to any one of claims 1 to 12, both ends of the lead wire being exposed to the outside of the magnet, characterized in that the inductance component is coated with a layer of resin; the magnet comprises iron-based magnetic powder particles, wherein the iron-based magnetic powder particles are coated with a composite insulating layer of ferrous salt and silicon dioxide, and the inductance element can be subjected to high-temperature heat treatment at 500-960 ℃;

the surface of the lead is coated with a nano composite insulating layer, and the nano composite insulating layer is uniformly distributed with nano oxides of silicon dioxide and aluminum oxide adhered by a silane coupling agent.

14. The inductive component of claim 13, wherein a wire slot is provided in the magnet extending from one end of the magnet to the other end of the magnet, the wire is inserted in the wire slot, and both ends of the wire are exposed out of the wire slot; the two ends of the lead are connected with electrode pins, the edges of the top surfaces of the two ends of the magnet are provided with accommodating grooves for accommodating the electrode pins, and the width of the accommodating grooves is equal to that of the magnet; the electrode pins are formed by bending two ends of a wire, which are exposed out of the magnet, of the wire, the two ends of the wire are symmetrically attached to the surface of the magnet, and the width of the two end parts of the wire is larger than that of the middle part of the wire.

15. The inductive component of claim 14, wherein a wire slot is provided in the magnet extending from one end of the magnet to the other end of the magnet, the wire is inserted in the wire slot, and both ends of the wire are exposed out of the wire slot; the two ends of the lead are connected with electrode pins, the edges of the top surfaces of the two ends of the magnet are provided with accommodating grooves for accommodating the electrode pins, and the width of the accommodating grooves is equal to that of the magnet; the electrode pins are formed by bending the middle part of the tinned wire, and the electrode pins are bent to form a first folding pin and a second folding pin; the first folding leg of the electrode pin is provided with a pin fixing groove, two ends of a wire can be inserted into the pin fixing groove on the first folding leg of the electrode pin and welded in the pin fixing groove through brazing or laser, and the second folding leg of the electrode pin can be tightly attached in the accommodating groove of the magnet; the width of the second folding leg is larger than that of the lead, and the width of the second folding leg is smaller than or equal to that of the magnet.

16. An inductive element according to claim 14 or 15, wherein said magnet consists of a pre-formed bottom blank and top blank; the lead is placed on the prefabricated base blank, and two ends of the lead are exposed out of the prefabricated base blank; the top surface of the prefabricated bottom blank is provided with a limiting wire groove parallel to the length direction of the prefabricated bottom blank, the middle part of the wire is arranged in the limiting wire groove, and two sides of the wire are propped against two side walls of the limiting wire groove; the preform bottom can be mated with the top to compress the wire.