CN105914003A - Inductor and manufacturing method thereof - Google Patents

Abstract

The invention relates to an inductor and a manufacturing method thereof. The magnetic body comprises a first magnetic powder and a second magnetic powder, wherein the Vickers hardness of the first magnetic powder is greater than that of the second magnetic powder, the average particle size of the first magnetic powder is greater than that of the second magnetic powder, and the first magnetic powder and the second magnetic powder are mixed.

Description

Inductor and method of making the same

The present invention is a divisional application of a Chinese patent application with an application date of May 27, 2009, an application number of 200910143076.9, and an invention title of "Inductor and Its Manufacturing Method".

technical field

The invention relates to a magnetic element and a manufacturing method thereof, in particular to an inductor and a manufacturing method thereof.

Background technique

The function of the inductor is to stabilize the current in the circuit and achieve the effect of filtering out noise. The function is similar to that of a capacitor. It also stores and releases the electric energy in the circuit to adjust the stability of the current. Compared with the capacitor, the electric field ( Charge) to store electrical energy, while inductors store electrical energy in the form of a magnetic field. In the application of the inductor, there will be energy loss of the wire and the energy loss of the magnetic core (generally called core loss).

The lead wire of a kind of inductor in the prior art is embedded in the magnetic body, and the method for forming this kind of inductor is to put the lead wire in the mold first, and put the iron with the same particle size as the adhesive The powder is filled in the mold to cover the wire, and then the iron powder is compressed into a magnetic body by pressure molding, and then the adhesive is heated to make it solidify. The magnetic permeability of an inductor using iron powder as a magnetic body will drop sharply at high frequencies above 10KHz. Therefore, conventional inductors cannot be used for high-frequency applications.

It can be seen that the above-mentioned existing inductor and its manufacturing method obviously still have inconveniences and defects in terms of product structure, manufacturing method and use, and need to be further improved urgently. In order to solve the above-mentioned problems, the relevant manufacturers have tried their best to find a solution, but no suitable design has been developed for a long time, and there is no suitable structure and method for general products and methods to solve the above-mentioned problems. This is obviously a problem that relevant industry players are eager to solve. Therefore, how to create a new inductor and its manufacturing method is one of the current important research and development topics, and it has also become a goal that the industry needs to improve.

Contents of the invention

The purpose of the present invention is to overcome the defects of existing inductors and provide a new inductor. The technical problem to be solved is to make its magnetic body contain a variety of magnetic powders with different hardness and different average particle sizes, so as to Improve the magnetic permeability of the inductor, which is very suitable for practical use.

Another object of the present invention is to overcome the defects of the existing inductor manufacturing method and provide a new inductor manufacturing method. The technical problem to be solved is to make it use different hardness and different average particle diameters. A variety of magnetic powders are used to form a magnetic body to increase the magnetic permeability of the inductor, which is more suitable for practical use.

The purpose of the present invention and the solution to its technical problems are achieved by adopting the following technical solutions. An inductor proposed according to the present invention includes a magnetic body and a wire. The magnetic body includes a first magnetic powder and a second magnetic powder, wherein the Vickers Hardness of the first magnetic powder is greater than that of the second magnetic powder, and the average particle size of the first magnetic powder is greater than that of the second magnetic powder. The average particle diameter of the magnetic powder, the first magnetic powder is mixed with the second magnetic powder.

The purpose of the present invention and the solution to its technical problems can also be further realized by adopting the following technical measures.

In an embodiment of the present invention, the Vickers hardness of the first magnetic powder is greater than or equal to 150, and the Vickers hardness of the second magnetic powder is less than or equal to 100.

In an embodiment of the present invention, the Vickers hardness of the first magnetic powder is greater than or equal to 250, and the Vickers hardness of the second magnetic powder is less than or equal to 80.

In an embodiment of the present invention, the average particle diameter of the first magnetic powder is substantially 10 microns to 40 microns.

In an embodiment of the present invention, the average particle size of the second magnetic powder is less than or equal to 10 microns.

In an embodiment of the present invention, the average particle size of the second magnetic powder is substantially less than or equal to 4 microns.

In an embodiment of the present invention, the ratio of the average particle size of the first magnetic powder to the average particle size of the second magnetic powder is greater than 2.

In an embodiment of the present invention, the ratio of the average particle size of the first magnetic powder to the average particle size of the second magnetic powder is 2.5-10.

In an embodiment of the invention, the material of the first magnetic powder includes metal alloy.

In an embodiment of the present invention, the material of the first magnetic powder includes Fe-Cr-Si alloy, Fe-Ni alloy, amorphous alloy, Fe-Si alloy or Fe-Al-Si alloy.

In an embodiment of the invention, the material of the second magnetic powder includes iron or iron alloy.

In an embodiment of the invention, the material of the first magnetic powder includes amorphous alloy, and the material of the second magnetic powder includes iron.

In an embodiment of the invention, the ratio of the weight of the first magnetic powder to the weight of the second magnetic powder is 0.25-4.

In one embodiment of the present invention, when the material of the first magnetic powder includes amorphous alloy and the material of the second magnetic powder includes iron, the ratio of the weight of the first magnetic powder to the weight of the second magnetic powder is 0.67 to 1.5.

In an embodiment of the present invention, when the material of the first magnetic powder includes FeCrSi alloy and the material of the second magnetic powder includes iron, the ratio of the weight of the first magnetic powder to the weight of the second magnetic powder is 1.5 to 4.

In one embodiment of the present invention, the inductor further includes a binder, which joins the first magnetic powder and the second magnetic powder, and the content of the binder is 2% by weight (wt%)-3wt% of the total weight of the magnetic body. .

In an embodiment of the invention, the material of the adhesive is thermosetting resin.

In an embodiment of the present invention, the wire has an embedded portion embedded in the magnetic body or has a winding portion wound on the magnetic body.

In an embodiment of the present invention, the magnetic body is formed by a forming process (ie, manufacturing process, referred to herein as a process), and the forming pressure of the forming process is 6 tons per square centimeter to 11 tons per square centimeter.

In an embodiment of the present invention, the magnetic body is subjected to a heating process, and the temperature of the heating process is below 300°C.

The purpose of the present invention and the solution to its technical problem also adopt the following technical solutions to achieve. A manufacturing method of an inductor according to the present invention is as follows. First, a wire is provided. Next, a mixture is provided, the mixture includes a first magnetic powder, a second magnetic powder and a binder, wherein the Vickers hardness of the first magnetic powder is greater than the Vickers hardness of the second magnetic powder, and the average of the first magnetic powder The particle diameter is larger than the average particle diameter of the second magnetic powder. The binder is mixed with the first magnetic powder and the second magnetic powder. Then, a molding process is performed on the mixture to form a magnetic body. Afterwards, the adhesive is cured.

The purpose of the present invention and the solution to its technical problems can also be further realized by adopting the following technical measures.

In an embodiment of the present invention, the adhesive is cured by heating, and the heating temperature is below 300°C.

In an embodiment of the present invention, during the molding process, a molding pressure is applied to the mixture, and the molding pressure is 6 tons per square centimeter to 11 tons per square centimeter.

In an embodiment of the present invention, during the molding process of the mixture, the magnetic body covers an embedded portion of the wire.

In an embodiment of the present invention, after the adhesive is cured, a winding portion of the wire is wound on the magnetic body.

By means of the above-mentioned technical solution, the inductor and its manufacturing method of the present invention have at least the following advantages and beneficial effects: the present invention uses magnetic powders with different average particle diameters to form magnetic bodies, therefore, in the molding process, the magnetic powder with a small average particle diameter The magnetic powder will fill in the gaps between the magnetic powders with a large average particle size, so that the compression density increases, thereby increasing the magnetic permeability of the inductor. In addition, the present invention uses magnetic powders with different hardnesses to form the magnetic body, so the strain generated by the magnetic powders during the molding process is greatly reduced, thereby reducing the magnetic loss of the inductor of the present invention. In addition, the present invention can avoid the problem of conducting high-temperature heat treatment on the inductor to eliminate the strain of the magnetic powder and prevent the wire from being oxidized due to the inability to withstand high temperature.

To sum up, the inductor and its manufacturing method of the present invention include a magnetic body and a wire. The magnetic body includes a first magnetic powder and a second magnetic powder, wherein the Vickers hardness of the first magnetic powder is greater than the Vickers hardness of the second magnetic powder, and the average particle size of the first magnetic powder is greater than that of the second magnetic powder. particle size, the first magnetic powder is mixed with the second magnetic powder. The present invention has significant progress in technology, and has obvious positive effects, and is a novel, progressive and practical new design.

The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the description, and in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable , the following preferred embodiments are cited in detail, and in conjunction with the accompanying drawings, the detailed description is as follows.

Description of drawings

FIG. 1 is a cross-sectional view of an inductor according to an embodiment of the present invention.

2A to 2D are process cross-sectional views of the inductor of FIG. 1 according to the present invention.

FIG. 3 is a schematic diagram of an inductor according to another embodiment of the present invention.

FIG. 4 is a cross-sectional view of an inductor according to another embodiment of the present invention.

5A to 5C are process sectional views of the inductor shown in FIG. 4 of the present invention.

FIG. 6 is a schematic diagram of an inductor according to yet another embodiment of the present invention.

FIG. 7 is a schematic diagram showing the variation of the inductance value of the inductor at two frequencies when the ratio of the first magnetic powder and the second magnetic powder in the magnetic body is changed.

FIG. 8 is a schematic diagram showing the variation of the inductance value of the inductor at two frequencies when the ratio of the first magnetic powder and the second magnetic powder in the magnetic body is changed.

FIG. 9 is a graph showing inductance variation curves of inductors using wires with different wire diameters.

FIG. 10A is a schematic diagram showing the variation of the inductance value of the inductor and the density of the magnetic body when the ratio of the first magnetic powder and the second magnetic powder in the magnetic body is changed.

FIG. 10B is a schematic diagram showing changes in the density and permeability of the magnetic body of the inductor when the ratio of the first magnetic powder and the second magnetic powder in the magnetic body is changed.

FIG. 11A shows the variation of the inductance of the inductor when the ratio of the first magnetic powder and the second magnetic powder in the magnetic body is changed, and a schematic diagram of the variation of the inductance of the inductor under two applied frequencies.

FIG. 11B shows the variation of the inductance value of the inductor when the ratio of the first magnetic powder and the second magnetic powder in the magnetic body is changed, and a schematic diagram showing the variation of the inductance value of the inductor formed by two molding pressures .

FIG. 12 is a schematic diagram showing the variation of the inductance value of the inductor at two frequencies when the ratio of the first magnetic powder and the second magnetic powder in the magnetic body is changed.

100, 200, 300: Inductors 110, 210, 310, 410: Magnetic bodies

112: first magnetic powder 114: second magnetic powder

116: Adhesive 120, 320, 420, 320: Wire

122, 222: embedded part 222a: bending structure

124, 322, 422, 322: Winding part 312: Center column

314: first plate-shaped body 316: second plate-shaped body

312a, 312b: end 330: magnetic material

412: first surface 414: second surface

416: through hole 418: third surface

310: Formed body C: Winding space

D1, D2: Average particle size E1, E2: End

G: Slit M: Mixture

S1, S2: Side walls S3: One side

detailed description

In order to further explain the technical means and effects of the present invention to achieve the intended purpose of the invention, below in conjunction with the accompanying drawings and preferred embodiments, the specific implementation, structure, method, Steps, features and effects thereof are described in detail below.

The aforementioned and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of preferred embodiments with reference to the drawings. Through the description of specific embodiments, a more in-depth and specific understanding of the technical means and effects adopted by the present invention to achieve the intended purpose can be obtained. However, the accompanying drawings are only for reference and description, and are not used to explain the present invention. be restricted.

FIG. 1 is a cross-sectional view of an inductor according to an embodiment of the present invention. Please refer to FIG. 1 , the inductor 100 of this embodiment includes a magnetic body 110 and a wire 120 . The magnetic body 110 includes a first magnetic powder 112 and a second magnetic powder 114 , and the first magnetic powder 112 and the second magnetic powder 114 are mixed. Wherein, the magnetic body 110 is formed by a molding process. The Vickers Hardness of the first magnetic powder 112 is greater than the Vickers Hardness of the second magnetic powder 114 . The Vickers hardness of the first magnetic powder 112 is, for example, greater than or equal to 150. Preferably, the Vickers hardness of the first magnetic powder 112 is greater than or equal to 250. The Vickers hardness of the second magnetic powder 114 is, for example, less than or equal to 100. Preferably, the Vickers hardness of the second magnetic powder 114 is less than or equal to 80.

The mean particle diameter D1 of the first magnetic powder 112 is greater than the mean particle diameter D2 of the second magnetic powder 114 , and the mean particle diameter D2 of the second magnetic powder 114 is less than or equal to 10 microns.

The average particle diameter D1 of the first magnetic powder 112 may be substantially 10 microns to 40 microns, and the average particle diameter D2 of the second magnetic powder 114 may be substantially less than or equal to 4 microns. The ratio of the average particle diameter D1 of the first magnetic powder 112 to the average particle diameter D2 of the second magnetic powder 114 is, for example, greater than 2. Preferably, the ratio of the average particle diameter D1 to the average particle diameter D2 is 2.5-10.

The material of the first magnetic powder 112 is, for example, metal alloy, and the metal alloy is, for example, iron-chromium-silicon alloy, iron-nickel alloy , amorphous alloy, iron-silicon alloy or iron-aluminum-silicon alloy. The material of the second magnetic powder 114 is, for example, iron or iron alloy. Preferably, the material of the first magnetic powder 112 is, for example, amorphous alloy, and the material of the second magnetic powder 114 is, for example , iron. The magnetic body 110 further includes a binder (not shown), and the binder is mixed with the first magnetic powder 112 and the second magnetic powder 114 . The first magnetic powder 112 and the second magnetic powder 114 can be bonded to each other by an adhesive. The material of the adhesive can be thermosetting resin, such as epoxy resin. The content of the binder is 2 wt % to 3 wt % of the total weight of the magnetic body 110 , and the content of the first magnetic powder 112 and the second magnetic powder 114 is 98 wt % to 97 wt % of the total weight of the magnetic body 110 . And the weight proportion of the first magnetic powder is 20wt%～80wt% and the proportion of the second magnetic powder is 80wt%～20wt%, that is, the ratio of the weight of the first magnetic powder 112 to the weight of the second magnetic powder 114 can be 0.25 to 4 .

The wire 120 has an embedded part 122 embedded in the magnetic body 110 and two ends E1 and E2 extending out of the magnetic core 110 from the two ends of the embedded part 122 respectively. The ends E1 and E2 are suitable for connecting with other electronic components. The elements (not shown) are electrically connected. In detail, the magnetic body 110 is a rectangular body, and the ends E1 and E2 can respectively extend along two opposite side walls S1 and S2 of the magnetic body 110 to one side S3 of the magnetic body 110, so that the inductor 100 can be surface It is electrically connected to other electronic components by means of adhesion. The wire 120 is, for example, a copper wire, and the embedded portion 122 is, for example, a wound coil.

It should be noted that the average particle size and hardness of the first magnetic powder 112 used in this embodiment are larger than the average particle size and hardness of the second magnetic powder 114, therefore, in the molding process, the second magnetic powder 114 will easily fill In the gap between the first magnetic powder 112, the strain generated by the mutual extrusion of the second magnetic powder 114 and the first magnetic powder 112 can also be reduced , so that the compression density is increased and the magnetic permeability of the formed inductor can be improved. , and can avoid the use of larger molding pressure and high temperature heat treatment to improve the compression density and magnetic permeability.

Furthermore, since the magnetic body 110 contains the first magnetic powder 112 with lower magnetic loss than iron powder, compared with the conventional inductors that use iron powder as the magnetic body, this embodiment can provide a magnetic loss lower Low inductor, so that the efficiency of the inductor is improved . Furthermore, the material cost of the magnetic body 110 comprising the first magnetic powder 112 and the second magnetic powder 114 can be lower than the material cost of the magnetic body entirely made of metal alloy.

2A to 2D are process cross-sectional views of the inductor of FIG. 1 according to the present invention. For the detailed manufacturing process of the inductor 100 of FIG. 1 , please refer to FIGS. 2A-2D . First, please refer to FIG. 2A , a wire 120 is provided. Next, please refer to FIG. 2B , a mixture M is provided, and the mixture M includes the first magnetic powder 112 , the second magnetic powder 114 and a binder (not shown). Afterwards, referring to FIG. 2C , an embedded portion 122 of the wire 120 is disposed in the mold cavity (not shown), and the two ends E1 and E2 of the wire 120 extend out of the mold cavity, and then the mixture M is filled in the mold cavity. hole. Afterwards, a molding process is performed on the mixture M to form a magnetic body 110 covering the embedded portion 122. The molding process is, for example, applying a molding pressure to the mixture M to compress the first magnetic powder 112 and the second magnetic powder 114. with adhesive. In this embodiment, the molding process performed on the mixture M is a pressure molding process, and the pressure applied to the mixture M is, for example, 6 tons per square centimeter to 11 tons per square centimeter. In other embodiments, the forming process can also be suitable forming process such as casting forming process or injection forming process. Afterwards, for example, the adhesive is cured by heating, and the heating temperature is equal to or slightly higher than the curing temperature of the adhesive, for example, below 300°C. It should be noted that the heating temperature used in this embodiment is only suitable for curing Adhesive. Finally, referring to FIG. 2D , the ends E1 and E2 are bent so that the ends E1 and E2 respectively extend to one side S3 of the magnetic body 110 along two opposite side walls S1 and S2 of the magnetic body 110 .

FIG. 3 is a schematic diagram illustrating an inductor according to another embodiment of the present invention. Please refer to FIG. 3 , in this embodiment, the material of the magnetic body 210 is the same as that of the magnetic core 110 in FIG. 1 , which will not be repeated here. The difference between the inductor 200 of this embodiment and the inductor 100 in FIG. 1 is that the embedded portion 222 may have a plurality of bent structures 222a, and these bent structures 222a are substantially located on the same plane.

FIG. 4 is a cross-sectional view of an inductor according to another embodiment of the present invention. Please refer to FIG. 4 , in this embodiment, the material of the magnetic body 310 is the same as that of the magnetic core 110 in FIG. 1 , which will not be repeated here. The difference between the inductor 300 of this embodiment and the inductor 100 of FIG. 1 is that the magnetic body 310 of this embodiment is a drum-shaped structure, and the wire 320 is located outside the magnetic body 310 . The magnetic body 310 of this embodiment includes a central column 312, a first plate-shaped body 314, and a second plate-shaped body 316, wherein the two ends 312a, 312b of the central column 312 are respectively connected to the first plate-shaped body 314 and the second plate-shaped body 314. The plate-shaped body 316 , and the wire 320 is wound on the central post 312 . Specifically, a winding space C is formed between the first plate-shaped body 314, the second plate-shaped body 316 and the central column 312, and the wire 320 has two ends E1, E2 and a wire between the two ends E1, E2. Winding part 322 . The winding part 322 is located in the winding space C and is wound on the center column 312, and the two ends E1, E2 extend from the inside of the winding space C to the outside of the winding space C to communicate with other electronic components (not shown). electrical connection. In addition, a magnetic material 330 or a resin material (not shown) can be selectively filled in the winding space C to fill the winding space C and cover the winding portion 322 of the wire 320 .

5A to 5C are process sectional views of the inductor shown in FIG. 4 of the present invention. For the detailed manufacturing process of the inductor 300 in FIG. 4 , please refer to FIGS. 5A-5C . First, please refer to FIG. 5A , a mixture M is provided, and the material of the mixture M is the same as that of the mixture M in FIG. 2B . Next, referring to FIG. 5B , a molding process is performed on the mixture M to form a magnetic body 310 . In this embodiment, the molding process includes a pressure molding process, a casting molding process or an injection molding process, and in the pressure molding process, the pressure applied to the mixture M is, for example, 6 tons per square centimeter to 11 tons per square centimeter. After that, for example, the adhesive (not shown) is cured by heating, and the heating temperature is equal to or slightly higher than the curing temperature of the adhesive, for example, below 300°C. It is worth noting that the heating method used in this embodiment The temperature is only suitable for curing the adhesive. Finally, referring to FIG. 5C , the wire winding portion 322 of the wire 320 is wound on the magnetic body 310 .

FIG. 6 is a schematic diagram of an inductor according to yet another embodiment of the present invention. Please refer to FIG. 6 , in this embodiment, the material of the magnetic body 410 is the same as that of the magnetic body 110 in FIG. 1 , and details will not be repeated here. In this embodiment, the magnetic body 410 has a first surface 412 , a second surface 414 opposite to the first surface 412 , and a through hole 416 passing through the first surface 412 and the second surface 414 . The wire 420 is, for example, a conductive strip. The wire 420 has two ends E1 , E2 and a winding portion 422 located between the two ends E1 , E2 . The winding portion 422 passes through the through hole 416 , and the end portions E1 , E2 respectively extend along the first surface 412 and the second surface 414 to a third surface 418 of the magnetic body 410 . The third surface 418 is connected between the first surface 412 and the second surface 414 . The magnetic body 410 optionally has a slit G passing through the third surface 418 and communicating with the through hole 416 .

The following will introduce the results of electrical tests on the inductors 100 , 300 with different ratios of the first magnetic powder and the second magnetic powder.

【Experiment 1】

The structure of the inductor in Experiment 1 is the same as that of the inductor 100 in Fig. 1, and the wire diameter A of the wire 120 is 0.32 millimeters, the diameter B of the coil is 2.4 millimeters, the number of turns of the coil is 11.5 turns, and the magnetic body 110 The molding pressure was 11 tons per square centimeter. The main components, average particle size and hardness of the first magnetic powder and the second magnetic powder used in Experiment 1 are listed in Table 1 in detail.

Table 1

It can be seen from Table 1 that the ratio of D1 to D2 is 2.5 . FIG. 7 shows the change of the inductance value of the inductor at two frequencies (25KHz and 100KHz) when the ratio of the first magnetic powder and the second magnetic powder in the magnetic body is changed. Referring to FIG. 7 , the inductance value of the inductor when the proportion of the first magnetic powder is 20wt%-80wt% is greater than that of the inductor when the proportion of the first magnetic powder or the second magnetic powder is 100wt%. Preferably, the proportion of the first magnetic powder is 60wt% and the proportion of the second magnetic powder is 40wt% , that is, the ratio of the weight of the first magnetic powder to the weight of the second magnetic powder is 1.5, or the first magnetic powder The ratio of the second magnetic powder is 60wt%-80wt% and the second magnetic powder is 40wt%-20wt%, that is, the ratio of the weight of the first magnetic powder to the weight of the second magnetic powder is 1.5-4 .

【Experiment 2】

The structure of the inductor of Experiment 2 is the same as that of the inductor 100 of Fig. 1, and the wire diameter A of the wire 120 is 0.32 millimeters, the diameter B of the coil is 2.4 millimeters, the number of turns of the coil is 11.5 turns, and the magnetic body 110 The molding pressure was 11 tons per square centimeter. The main components, average particle size and hardness of the first magnetic powder and the second magnetic powder used in Experiment 2 are listed in Table 2 in detail.

Table 2

FIG. 8 shows the variation of the inductance value of the inductor at two frequencies when the ratio of the first magnetic powder and the second magnetic powder in the magnetic body is changed. Please refer to Fig. 8, when the composition of the second magnetic powder is iron and the ratio of D1 to D2 is 10, the inductance value of the inductor when the proportion of the first magnetic powder is 20wt% to 80wt% is greater than that of the first magnetic powder or The inductance value of the inductor when the proportion of the second magnetic powder is 100wt%. Preferably, the proportion of the first magnetic powder is 40wt% and the proportion of the second magnetic powder is 60wt%, that is, the ratio of the weight of the first magnetic powder to the weight of the second magnetic powder is 0.67, or the first magnetic powder The proportion of the magnetic powder is 40wt%-60wt% and the proportion of the second magnetic powder is 60wt%-40wt%, that is, the ratio of the weight of the first magnetic powder to the weight of the second magnetic powder is 0.67-1.5.

And when the composition of the second magnetic powder is FeCrSi alloy and the ratio of D1 and D2 is 4, the inductance value of the inductor when the ratio of the first magnetic powder is 20wt%～80wt% is greater than the ratio of the first magnetic powder is The inductance value of the inductor at 100wt%, and the inductance value of the inductor when the proportion of the first magnetic powder is 20wt% to 40wt% is slightly higher than the inductance value of the inductor when the proportion of the second magnetic powder is 100wt%, Therefore, it is preferable that the proportion of the first magnetic powder is 20wt%-40wt% and the proportion of the second magnetic powder is 80wt%-60wt%, that is, the ratio of the weight of the first magnetic powder to the weight of the second magnetic powder is 0.25 to 0.67.

From the above, it can be known that the second magnetic powder with different average particle size is used together with the same first magnetic powder, the smaller the average particle size can be obtained, the better the effect of increasing the inductance value of the inductor is.

The following experiments were carried out with a magnetic body containing 40 wt% of 40 micron amorphous alloy and 60 wt% of 4 micron iron powder. Table 3 lists the variation of the magnetic loss, Table 4 lists the variation of the efficiency, and FIG. 9 shows the curves of the variation of the inductance of the inductor using wires with different wire diameters. The frequency of the experiment in Table 3 is 300KHz, and the magnetic induction is 30mT. The applied current for Table 4 is 2 amps.

table 3

Table 4

As can be seen from Table 3, the amorphous alloy of 40 microns is used as the first magnetic powder in the present embodiment, the iron powder of 4 microns is the second magnetic powder, and the ratio of the first magnetic powder is 40wt%, and the second magnetic powder The ratio of the iron powder is 60wt%, and the magnetic loss obtained can be lower than that of iron powder ratio of 100wt%, amorphous alloy ratio of 100wt%, and amorphous alloy ratio of 100wt% (high-temperature heat treatment after the forming process), and forming The greater the pressure, the lower the magnetic loss. Therefore, it can be confirmed that the first magnetic powder and the second magnetic powder magnetic body with different average particle diameters and hardnesses can be appropriately selected in this embodiment to obtain lower magnetic loss without high temperature heat treatment, so high temperature can be omitted. heat treatment steps , and simplify the process. Moreover, the material cost of the magnetic body 110 comprising the first magnetic powder 112 and the second magnetic powder 114 can be lower than that of the first magnetic powder with a proportion of 100 wt%.

It can be seen from Table 4 that when the frequency is 25KHz, the efficiency of the inductor of this embodiment can reach more than 76% , and when the frequency is 300KHz, the efficiency of the inductor of this embodiment can reach more than 90% . It can be seen that the inductor of this embodiment has Excellent efficiency performance. It is worth noting that the efficiency of molding pressure at 8.5 tons per square centimeter is better than that at 11 tons per square centimeter.

It can be seen from FIG. 9 that under the same coil diameter B and the number of turns, the smaller the wire diameter is, the higher the inductance value of the inductor is. Therefore, the inductance value of the inductor can be adjusted by changing the diameter of the wire.

【Experiment 3】

The structure of the inductor in Experiment 3 is the same as that of the inductor 100 in Fig. 1, and the wire diameter A of the wire 120 is 0.32 millimeters, the diameter B of the coil is 2.4 millimeters, the number of turns of the coil is 13.5 turns, and the magnetic body 110 The molding pressure was 11 tons per square centimeter. The main components, average particle size and hardness of the first magnetic powder and the second magnetic powder used in Experiment 3 are listed in Table 5 in detail.

table 5

It can be seen from Table 5 that the ratio of D1 to D2 is 5. FIG. 10A shows the variation of the inductance value of the inductor and the density of the magnetic body when the ratio of the first magnetic powder and the second magnetic powder in the magnetic body is changed. FIG. 10B shows the variation of the magnetic density and magnetic permeability of the inductor when the ratio of the first magnetic powder and the second magnetic powder in the magnetic body is changed.

Please refer to Figure 10A and Figure 10B, when the ratio of the first magnetic powder is 20wt% to 60wt%, the inductance value, magnetic body density and magnetic permeability of the inductor are all greater than the ratio of the first magnetic powder or the second magnetic powder is 100wt% The inductance value, magnetic body density and magnetic permeability of the inductor at that time. Preferably, the proportion of the first magnetic powder is 40wt% and the proportion of the second magnetic powder is 60wt%, that is, the ratio of the weight of the first magnetic powder to the weight of the second magnetic powder is 0.67, or the first magnetic powder The ratio of the second magnetic powder is 40wt%-60wt% and the second magnetic powder is 60wt%-40wt%, that is, the ratio of the weight of the first magnetic powder to the weight of the second magnetic powder is 0.67-1.5 .

Table 6 lists the efficiency performance of the inductor of this embodiment under the same current (2 amperes), the same molding pressure (11 tons per square centimeter) and two frequencies.

Table 6

It can be seen from Table 6 that when the proportion of amorphous alloy is 20wt% ~ 40wt% and the proportion of iron powder is 80wt% ~ 60wt%, when the frequency is 25KHz, the efficiency can reach more than 75% , and the frequency is 300KHz , the efficiency can reach more than 90% . It can be seen that the inductor of this embodiment has excellent efficiency performance.

【Experiment 4】

The structure of the inductor in Experiment 4 is the same as that of the inductor 300 in Fig. 4, and the wire diameter A of the wire 320 is 0.32 millimeters, the diameter B of the coil is 2.4 millimeters, the number of turns of the coil is 11.5 turns, and the magnetic body 310 The molding pressure is 8 or 11 tons per square centimeter. The main components, average particle size and hardness of the first magnetic powder and the second magnetic powder used in Experiment 4 are listed in Table 7 in detail.

Table 7

It can be seen from Table 7 that the ratio of D1 to D2 is 2.5. 11A shows the variation of the inductance of the inductor when the ratio of the first magnetic powder and the second magnetic powder in the magnetic body is changed, and shows the variation of the inductance of the inductor under two applied frequencies. 11B shows the variation of the inductance of the inductor when the ratio of the first magnetic powder and the second magnetic powder in the magnetic body is changed, and shows the variation of the inductance of the inductor formed by two molding pressures.

It can be seen from FIG. 11A that the inductance value of the inductor when the proportion of the first magnetic powder is 20wt%-80wt% is greater than that of the inductor when the proportion of the first magnetic powder or the second magnetic powder is 100wt%. Preferably, the proportion of the first magnetic powder is 60wt% and the proportion of the second magnetic powder is 40wt%, that is , the ratio of the weight of the first magnetic powder to the weight of the second magnetic powder is 1.5, or the first magnetic powder The ratio of the second magnetic powder is 60wt%-80wt% and the second magnetic powder is 40wt%-20wt%, that is, the ratio of the weight of the first magnetic powder to the weight of the second magnetic powder is 1.5-4 . In addition, it can be known from FIG. 11B that when the molding pressure is higher, the magnetic permeability of the inductor is larger. Therefore, the magnetic permeability of the inductor can be adjusted by changing the molding pressure.

【Experiment 5】

The structure of the inductor in Experiment 5 is the same as that of the inductor 300 in Fig. 4, and the wire diameter A of the wire 320 is 0.32 millimeters, the diameter B of the coil is 2.4 millimeters, the number of turns of the coil is 11.5 turns, and the magnetic body 310 The molding pressure was 11 tons per square centimeter. The main components, average particle size and hardness of the first magnetic powder and the second magnetic powder used in Experiment 5 are listed in Table 8 in detail.

Table 8

Please refer to Fig. 12, when the composition of the second magnetic powder is iron and the ratio of D1 to D2 is 10, the inductance value of the inductor when the proportion of the first magnetic powder is 20wt% to 80wt% is greater than that of the first magnetic powder or The inductance value of the inductor when the proportion of the second magnetic powder is 100wt%. Preferably, the proportion of the first magnetic powder is 40wt % and the proportion of the second magnetic powder is 60wt%, that is, the ratio of the weight of the first magnetic powder to the weight of the second magnetic powder is 0.67, or the first magnetic powder The proportion of the powder is 40wt%-60wt% and the proportion of the second magnetic powder is 60wt%-40wt%, that is, the ratio of the weight of the first magnetic powder to the weight of the second magnetic powder is 0.67-1.5.

And when the composition of the second magnetic powder is FeCrSi alloy and the ratio of D1 and D2 is 4, the inductance value of the inductor when the ratio of the first magnetic powder is 20wt%～80wt% is greater than the ratio of the first magnetic powder is The inductance value of the inductor when the proportion of the first magnetic powder is 20wt%～40wt% is slightly larger than the inductance value of the inductor when the proportion of the second magnetic powder is 100wt%, so , preferably the proportion of the first magnetic powder is 20wt% to 40wt% and the proportion of the second magnetic powder is 80wt% to 60wt% , that is, the ratio of the weight of the first magnetic powder to the weight of the second magnetic powder is 0.25 to 0.67.

From the above, it can be known that the second magnetic powder with different average particle size is used together with the same first magnetic powder, the smaller the average particle size can be obtained, the better the effect of increasing the inductance value of the inductor is.

In summary, the present invention has at least the following advantages:

1. The present invention uses magnetic powders with different average particle sizes to form a magnetic body. Therefore, in the molding process, magnetic powders with small average particle sizes will fill in the gaps between magnetic powders with large average particle sizes, resulting in compression The density increases, which in turn increases the magnetic permeability of the inductor.

2. The present invention uses magnetic powders with different hardness to form a magnetic body, and the magnetic powder with a small average particle size can accommodate It is easy to fill in the gaps between magnetic powders with large average particle diameters, so the forming pressure required for magnetic powders in the forming process is as high as And the generated strain is greatly reduced, thereby reducing the magnetic loss of the inductor of the present invention. And, the present invention can avoid the inductance The high-temperature heat treatment of the device can eliminate the strain of the magnetic powder and prevent the oxidation of the wire due to the inability to withstand high temperature.

3. The present invention uses the first magnetic powder and the second magnetic powder to make the magnetic body, so the magnetic permeability and corresponding inductance value of the inductor of the present invention are higher than those of the conventional ones at high frequencies (25KHz or 100KHz). Iron powder is used to make high magnetic body .

4. The present invention uses the first magnetic powder and the second magnetic powder of the metal alloy powder to make the magnetic body, and its material cost can be lower than the material cost of making the magnetic body entirely with the metal alloy powder.

The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this field Those skilled in the art, without departing from the scope of the technical solution of the present invention, may use the method and technical content disclosed above to make some changes or modify equivalent embodiments with equivalent changes, but if they do not depart from the content of the technical solution of the present invention, Any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims (13)

1. An inductor, characterized in that it comprises: a first magnetic powder; A second magnetic powder, the first magnetic powder is mixed with the second magnetic powder, wherein the ratio of the average particle diameter of the first magnetic powder to the average particle diameter of the second magnetic powder is greater than 2, wherein the mixed the first magnetic is not pre-oxidized to insulate its surface; and A wire with an insulating layer, wherein the first magnetic powder mixed with the second magnetic powder and the wire with an insulating layer embedded therein are integrally molded at a temperature below 300°C to form a magnetic body, wherein the first The two magnetic powders are filled in the gaps between the first magnetic powders to increase the density of the magnetic body, thereby increasing the magnetic permeability of the inductor. 2. The inductor according to claim 1, wherein the first magnetic powder has an average particle diameter of 10 microns to 40 microns. 3. The inductor according to claim 1, characterized in that, the average particle size of the second magnetic powder is less than or equal to 10 microns. 4 . The inductor according to claim 1 , wherein the material of the first magnetic powder comprises Fe-Cr-Si alloy, Fe-Ni alloy, amorphous alloy, Fe-Si alloy or Fe-Al-Si alloy. 5. The inductor according to claim 1, wherein the material of the second magnetic powder comprises iron or iron alloy. 6 . The inductor according to claim 1 , wherein the first magnetic powder is made of amorphous alloy, and the second magnetic powder is made of iron. 7 . The inductor according to claim 1 , wherein a weight ratio of the first magnetic powder to the second magnetic powder is between 0.25 and 4. 8 . 8. The inductor according to claim 1, wherein when the material of the first magnetic powder comprises an amorphous alloy and the material of the second magnetic powder comprises iron, the weight of the first magnetic powder and The weight ratio of the second magnetic powder is between 0.67 and 1.5. 9. The inductor according to claim 1, wherein when the material of the first magnetic powder comprises FeCrSi alloy and the material of the second magnetic powder comprises iron, the weight of the first magnetic powder is the same as The weight ratio of the second magnetic powder is between 1.5 and 4. 10. An inductor, characterized in that it comprises: a first magnetic powder; A second magnetic powder, the first magnetic powder is mixed with the second magnetic powder, wherein the ratio of the average particle diameter of the first magnetic powder to the average particle diameter of the second magnetic powder is greater than 2, wherein the mixed the first magnetic is not pre-oxidized to insulate its surface; and A coil, the coil is formed by a wire with an insulating layer, wherein the first magnetic powder mixed with the second magnetic powder and the coil embedded therein are integrally molded at a temperature below 300°C to form a magnetic body, Wherein the second magnetic powder fills the gaps between the first magnetic powders to increase the density of the magnetic body, thereby increasing the magnetic permeability of the inductor. 11. An inductor, characterized in that it comprises: a first magnetic powder; a second magnetic powder, the first magnetic powder is mixed with the second magnetic powder, wherein the ratio of the average particle diameter of the first magnetic powder to the average particle diameter of the second magnetic powder is between 2.5 and 10, wherein the mixed first magnetic is not pre-oxidized to insulate its surface; and A coil, the coil is formed by a wire with an insulating layer, wherein the first magnetic powder mixed with the second magnetic powder and the coil embedded therein are integrally molded at a temperature below 300°C to form a magnetic body, Wherein the second magnetic powder fills the gaps between the first magnetic powders to increase the density of the magnetic body, thereby increasing the magnetic permeability of the inductor. 12. An inductor, characterized in that it comprises: a first magnetic powder; A second magnetic powder, the first magnetic powder is mixed with the second magnetic powder, wherein the ratio of the average particle diameter of the first magnetic powder to the average particle diameter of the second magnetic powder is greater than 2, wherein the second The average particle size of the magnetic powder is less than or equal to 4 microns; and A wire with an insulating layer, wherein the first magnetic powder mixed with the second magnetic powder and the wire with an insulating layer embedded therein are integrally molded at a temperature below 300°C to form a magnetic body, wherein the first The two magnetic powders are filled in the gaps between the first magnetic powders to increase the density of the magnetic body, thereby increasing the magnetic permeability of the inductor. 13. A method for manufacturing an inductor, comprising the following steps: providing an insulated wire; A mixture is provided, the mixture comprising: a first magnetic powder; A second magnetic powder, the first magnetic powder is mixed with the second magnetic powder, wherein the ratio of the average particle diameter of the first magnetic powder to the average particle diameter of the second magnetic powder is greater than 2, wherein the mixed the first magnetic is not pre-oxidized to insulate its surface; and a binder mixed with the first magnetic powder and the second magnetic powder; performing a molding process on the wire and the mixture, wherein the mixed first magnetic powder and the second magnetic powder and the wire with an insulating layer embedded therein are integrally molded at a temperature below 300° C. to form a magnetic body, wherein the second magnetic powder is filled in the gaps between the first magnetic powders to increase the density of the magnetic body, thereby increasing the magnetic permeability of the inductor; and The adhesive is cured.