Inductor forming method and inductor

Abstract

The invention belongs to the technical field of electronic components, and discloses an inductor forming method and an inductor. The forming method of the inductor comprises the following steps: S10, preparation: providing magnetic glue and a coil; s20, forming: putting the coil into a forming mold, filling the magnetic glue to coat the coil, and heating to form a magnet; s30, baking: heating and baking the formed magnet; and S40, bending: bending and forming the two terminals of the coil, so that the two terminals are attached to the magnet to form electrodes. According to the forming method of the inductor, the magnet of the inductor is formed in a nearly non-pressure state, a paint film of a coil cannot be damaged, the short circuit risk of the inductor is avoided, the safety and reliability of the inductor are improved, and the application range is wider.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic components, and particularly to a forming method of an inductor and an inductor. Background Art

[0002] An inductor, also known as an inductance coil, can convert electrical energy into magnetic energy and store it, and is one of the basic components of an electronic circuit. The existing integrated molded inductor includes a magnet, a coil winding, and terminals. The magnet is formed by die-casting a winding body into the interior of metal magnetic powder, and the terminal pins are led out from the winding body and directly formed on the surface of the base body. Due to its fully enclosed structure, it has good magnetic shielding effect, can effectively reduce electromagnetic interference and avoid noise generation.

[0003] Currently, in the forming process of the integrated molded inductor, round wire or flat wire is used to wind into a certain inner diameter and number of turns according to product requirements, then powder is filled and compression molded, and then baked and cured. After curing and forming, the terminals on both sides of the inductor are bent to obtain a formed inductor that can be surface-mounted at the bottom. Since the coil will expand outward during compression molding, that is, the coil expansion size needs to be reserved, the space utilization rate of the inductor is reduced; and since the pressure of this compression molding is generally between 400 Mpa and 700 Mpa, when the coil and the powder are compression molded under the above pressure during the manufacturing process, the powder under high pressure will pierce the paint film of the coil, increasing the short-circuit risk between the internal circuits of the coil. Especially for high-frequency inductors, this problem is more serious and the short-circuit risk is higher.

[0004] Therefore, it is urgent to design a forming method of an inductor and an inductor to solve the above technical problems. Summary of the Invention

[0005] An object of the present invention is to provide a forming method of an inductor and an inductor, which can make the magnet of the inductor be formed under a nearly pressure-free state, will not damage the paint film of the coil, avoid the short-circuit risk of the inductor, improve the safety and reliability of the inductor, and have a wider application range.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] A forming method of an inductor includes the following steps:

[0008] S10. Preparation: Provide magnetic glue and a coil;

[0009] S20. Forming: Place the above coil into a forming mold, fill in the above magnetic glue to coat the above coil, and heat and form it into a magnet;

[0010] S30. Baking: Heat and bake the formed above magnet;

[0011] S40. Bending: Bend the two terminals of the above-mentioned coil to form a shape so that they fit onto the above-mentioned magnet to form electrodes.

[0012] Optionally, the above step S20 includes the following steps:

[0013] S21. Place the above-mentioned coil into the cavity of the above-mentioned molding die, cover the upper die of the above-mentioned molding die on the lower die of the above-mentioned molding die, and fix the two above-mentioned terminals;

[0014] S22. Provide the above-mentioned magnetic glue to the feeding position of the above-mentioned molding die, and heat the above-mentioned magnetic glue at the feeding position to soften the above-mentioned magnetic glue into a magnetic glue fluid;

[0015] S23. Inject the above-mentioned magnetic glue fluid into the above-mentioned cavity through the injection channel of the above-mentioned molding die, so that the above-mentioned magnetic glue fluid coats the above-mentioned coil and fills the above-mentioned cavity;

[0016] S24. Heat the above-mentioned magnetic glue fluid in the above-mentioned cavity to cure and form the above-mentioned magnet.

[0017] Optionally, when heating the above-mentioned magnetic glue at the above-mentioned feeding position in the above step S22, the temperature is T1 and the time is t1, 80°C ≤ T1 ≤ 120°C, 1 min ≤ t1 ≤ 3 min.

[0018] Optionally, when heating the above-mentioned magnetic glue in the above-mentioned cavity in the above step S24, the temperature is T2 and the time is t2, 160°C ≤ T2 ≤ 180°C, 1 min ≤ t2 ≤ 3 min.

[0019] Optionally, the above-mentioned magnetic glue includes magnetic powder and colloid, and the above-mentioned colloid coats the above-mentioned magnetic powder.

[0020] Optionally, the particle size of the above-mentioned magnetic powder is A, and the initial magnetic permeability of the above-mentioned magnetic powder is UI, 60 mesh ≤ A ≤ 300 mesh; 20 ≤ UI ≤ 40.

[0021] Optionally, the above-mentioned magnetic powder is at least one of alloy iron powder, carbonyl iron powder, amorphous powder, and nanocrystalline powder.

[0022] Optionally, the above-mentioned colloid includes thermosetting glue, thermoplastic glue, and lubricant.

[0023] Optionally, when heating and baking the above-mentioned formed magnet in the above step S30, the temperature is T3 and the time is t3, 160°C ≤ T3 ≤ 180°C, 60 min ≤ t2 ≤ 400 min.

[0024] Another object of the present invention is to provide an inductor, which is formed by using the inductor forming method described in any of the above solutions. The inductor includes a magnet, a coil, and two terminals. The coil is disposed within the magnet, and the two terminals are connected to the leads at both ends of the coil. The terminals penetrate through the magnet and are disposed in contact with the magnet. This inductor can increase the occupied area of the coil within the inductor, improve space utilization, and at the same time improve the safety and reliability of the inductor, with a wider range of applications.

[0025] Advantages of the present invention:

[0026] The present invention provides an inductor forming method and an inductor. The magnetic glue is directly cured by heating to form a magnet, without the need for pressure molding of magnetic powder, realizing near-pressureless molding of the inductor, and not causing the problem of piercing the paint film of the coil. Furthermore, the problem of coil short circuit of the inductor is avoided, improving the safety and reliability of the inductor formed by the inductor forming method of the present invention, enabling the inductor to also be used as a high-frequency inductor, with a wider range of uses. At the same time, when designing this inductor, there is no need to reserve additional space for the outward expansion of the coil after pressing, increasing the size of the coil, and thus increasing the size of the coil per unit volume of this inductor. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of the inductor forming method provided by the specific embodiment of the present invention Figure 1 ;

[0028] Figure 2 is a schematic diagram of the inductor forming method provided by the specific embodiment of the present invention Figure 2 ;

[0029] Figure 3 is a cross-sectional view of the forming die used in the inductor forming method provided by the specific embodiment of the present invention;

[0030] Figure 4 is a performance comparison table of the inductor provided by the specific embodiment of the present invention.

[0031] In the figure:

[0032] 100, magnetic glue; 10, cavity; 20, upper die; 30, lower die. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only for explaining the present invention, rather than limiting the present invention. Additionally, it should be noted that for the sake of description, only parts related to the present invention are shown in the drawings, rather than all structures.

[0034] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "under", and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0036] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0037] This embodiment provides a method for forming an inductor, which can form the magnet of the inductor in a nearly pressureless state, will not damage the paint film of the coil, avoid the risk of short circuit of the inductor, improve the safety and reliability of the inductor, and has a wider application range.

[0038] Please refer to Figures 1 to 3 , specifically, the method for forming the inductor includes the following steps:

[0039] S10. Preparation: Provide the magnetic glue 100 and the coil; that is, through this step, the magnetic glue 100 and the coil are formed to prepare the prerequisite for the subsequent formation of the inductor.

[0040] Specifically, the preparation of the above magnetic glue 100 includes step S11. Provide the colloid and the magnetic powder, and coat the colloid on the magnetic powder of a certain mesh number to form the magnetic glue 100.

[0041] Optionally, the above-mentioned magnetic glue 100 includes magnetic powder and colloid. The colloid coats the magnetic powder, that is, the magnetic powder is made into magnetic powder of a certain mesh number through the colloid, which also makes the magnetic glue 100 have certain adhesiveness and fluidity.

[0042] Optionally, the particle size of the above-mentioned magnetic powder is A, and the initial magnetic permeability of the magnetic powder is UI, 60 mesh ≤ A ≤ 300 mesh; 20 ≤ UI ≤ 40. By selecting the magnetic powder with the above particle size and initial magnetic permeability, and wrapping it with colloid outside, the magnetic glue 100 required for inductor forming can be formed.

[0043] Exemplarily, A can be 60 mesh, 70 mesh, 80 mesh, 90 mesh, 100 mesh, 120 mesh, 150 mesh, 180 mesh, 200 mesh, 220 mesh, 250 mesh, 280 mesh. Exemplarily, the UI value can be 20, 25, 30, 35, 40.

[0044] Optionally, the magnetic powder is at least one of alloy iron powder, carbonyl iron powder, amorphous powder, and nanocrystalline powder. The magnetic powder can be selected from one or a combination of the above powder materials, and can be adaptively selected according to actual needs, and no specific limitation is made here.

[0045] Further optionally, the above-mentioned colloid includes thermosetting glue, thermoplastic glue and lubricant, which are mixed by the above-mentioned various materials. The thermosetting glue is suitable for the fixation of the magnetic glue 100. The addition of the thermoplastic glue and the lubricant makes the colloid become a fluid when heated to a certain temperature range, which facilitates the flow of the magnetic glue 100.

[0046] Further, the preparation of the above-mentioned coil includes the following steps:

[0047] S12. Provide copper wire and wind the copper wire into a hollow coil through the middle column. That is, wind the copper wire along the middle column into a shape similar to a spring. Leads extend from both ends of the coil, and the diameter of the middle column is the diameter of the hollow in the middle of the coil.

[0048] Optionally, the above-mentioned copper wire can be selected as round copper wire or flat copper wire, and no specific limitation is made here.

[0049] Further optionally, the cross-sectional shape of the above-mentioned middle column can be circular, elliptical or kidney-shaped, and no specific limitation is made here.

[0050] S13. Spot welding: Provide terminals, and a plurality of coils are arranged side by side along the same winding direction. Spot weld the leads at both ends of the coils to the two terminals respectively. That is, fix the leads at both ends of a plurality of coils to the two terminals respectively, and the positive terminal and the negative terminal of the coil assembly can be determined, forming a positive electrode and a negative electrode.

[0051] S20. Molding: Place the coil into the molding die, fill in the magnetic glue 100 to wrap the coil, and heat it to form a magnet. By utilizing the fluid and adhesive properties of the magnetic glue 100 to fill the outside of the coil with the magnetic glue 100 and cure it to form a magnet, the basic molding of the inductor can be achieved.

[0052] Specifically, the above step S20 includes the following steps:

[0053] S21. Place the coil in the cavity 10 of the molding die, cover the upper die 20 of the molding die on the lower die 30 of the molding die, and fix the two terminals; thus, the positioning placement of the coil can be achieved, and it is ensured that the terminals are not completely wrapped in the cavity 10, thereby ensuring the electrical connection between the terminals and the outside.

[0054] S22. Provide the magnetic glue 100 to the feeding position of the molding die, and heat the magnetic glue 100 at the feeding position to soften the magnetic glue 100 into a magnetic glue fluid; that is, heat the magnetic glue 100 to a certain temperature so that the magnetic glue 100 becomes flowable, facilitating the flow of the magnetic glue 100 into the cavity 10 for molding.

[0055] Optionally, the temperature for heating the magnetic glue 100 at the feeding position in step S22 is T1, and the time is t1, 80°C ≤ T1 ≤ 120°C, 1 min ≤ t1 ≤ 3 min. By heating at the temperature T1 for the time t1, the softening of the magnetic glue 100 can be achieved.

[0056] Exemplarily, the T1 can be selected from 80°C, 90°C, 100°C, 110°C, 120°C. Exemplarily, the t1 can be selected from 1 min, 2 min, 3 min.

[0057] S23. Inject the magnetic glue fluid into the cavity 10 through the injection channel of the molding die, so that the magnetic glue fluid wraps the coil and fills the cavity 10; thus, the magnetic glue 100 is provided around the coil, and the molding of the flowable magnet can be achieved.

[0058] S24. Heat the magnetic glue fluid in the cavity 10 to cure the magnetic glue fluid into a magnet. Through further heating, the preliminary curing and molding of the magnet can be achieved, and thus the preliminary molding of the inductor can be achieved.

[0059] Optionally, the temperature for heating the magnetic glue fluid in the cavity 10 in step S24 is T2, and the time is t2, 160°C ≤ T2 ≤ 180°C, 1 min ≤ t2 ≤ 3 min. By heating at the temperature T2 for the time t2, the preliminary curing of the magnetic glue 100 fluid can be achieved.

[0060] Exemplarily, the T2 can be selected from 160°C, 170°C, 180°C. Exemplarily, the t2 can be selected from 1 min, 2 min, 3 min.

[0061] S30. Baking: Heat and bake the formed magnet; this can achieve the curing of the magnet, ensuring its formation. That is, at this temperature, the thermosetting glue in the colloid undergoes a chemical reaction, thereby causing the magnet to cure and preventing it from becoming fluid again upon heating, ensuring the stability of the inductor after formation.

[0062] Optionally, when heating and baking the formed magnet in step S30, the temperature is T3 and the time is t3, where 160°C ≤ T3 ≤ 180°C and 60 min ≤ t2 ≤ 400 min. By heating at temperature T3 for time t3, the curing of the magnetic glue 100 fluid can be achieved.

[0063] Exemplarily, T3 can be selected as 160°C, 170°C, 180°C. Exemplarily, t3 can be selected as 60 min, 120 min, 180 min, 240 min, 300 min, 360 min, 400 min.

[0064] Furthermore, the magnetic powder can be made of anti-rust magnetic material or non-anti-rust magnetic material; when the magnetic powder is made of anti-rust magnetic material, no insulation treatment is required; when the magnetic powder is made of non-anti-rust magnetic material, step S35 needs to be carried out after the baking in step S30: Insulate the formed magnet.

[0065] Optionally, the above insulation treatment is to coat a layer of insulating paint on the surface of the formed part; the specific implementation method is not specifically limited here. In this embodiment, the coating of the insulating paint is achieved by spraying.

[0066] S40. Bending: Bend the two terminals of the coil to form a shape that fits the magnet to form an electrode. This can achieve the fixation of the positive and negative terminals of the inductor.

[0067] In the forming method of the inductor of this embodiment, the magnetic glue 100 is directly cured by heating to form a magnet, without the need to press and form the magnetic powder, achieving the forming of the inductor in a nearly pressure-free state, not causing the problem of piercing the coil paint film, and thus avoiding the problem of coil short circuit of the inductor, improving the safety and reliability of the inductor formed by the forming method of this inductor, enabling the inductor to be used as a high-frequency inductor, with a wider range of use. At the same time, when designing this inductor, there is no need to reserve additional space for the outward expansion after coil pressing, increasing the size of the coil, and thus increasing the size of the coil per unit volume of the inductor.

[0068] This embodiment also provides an inductor. The inductor is manufactured by using the inductor forming method described in any of the above solutions, which can increase the occupied area of the coil in the inductor, improve the space utilization rate, and at the same time improve the safety and reliability of the inductor, with a wider scope of application.

[0069] Specifically, the inductor includes a magnet, a coil, and two terminals. The coil is disposed within the magnet, and the two terminals are connected to the leads at both ends of the coil. The terminals pass through the magnet and are disposed in contact with the magnet. By using the inductor forming method, the occupied area of the internal coil of the inductor is increased, the space utilization rate is improved, and at the same time, the safety and reliability of the inductor are improved, with a wider scope of application.

[0070] Next, with reference to Figure 4 , a comparison is made between the prior art solution and the inductors manufactured by the inductor forming methods in two of the present embodiments. As can be seen from Figure 4 , Example 1 is an inductor manufactured by the prior art solution. The wire diameter of the coil of this inductor is 0.3 mm, the diameter of the middle column is 3 mm, and the number of turns of the coil winding is 35.5 turns. Example 2 is an inductor one manufactured by the inductor forming method in the present embodiment. The wire diameter of the wire coil of this inductor is 0.3 mm, the diameter of the middle column is 4.4 mm, and the number of turns of the coil winding is 35.5 turns. Example 3 is an inductor two manufactured by the inductor forming method in the present embodiment. The wire diameter of the coil of this inductor is 0.36 mm, the diameter of the middle column is 4 mm, and the number of turns of the coil winding is 30.5 turns.

[0071] Through Figure 4 it can be seen that the inductance value, saturation current, and DC resistance of the inductor manufactured by the inductor forming method of the present embodiment in Example 2 are all higher than those of the solution in Example 1, and the short - circuit possibility of the inductors in Example 2 and Example 3 is 0, that is, the various performances of the inductors manufactured by the inductor forming method of the present embodiment have also been improved, and at the same time, the safety and reliability of the inductors have been improved.

[0072] Obviously, the above - mentioned embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re - adjustments, and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. Forming method of an inductor, characterized in that, it includes the following steps: S10. Preparation: Provide magnetic glue (100) and a coil; S20. Forming: Place the coil into a forming mold, fill in the magnetic glue (100) to coat the coil, and heat it to form a magnet; S30. Baking: Heat and bake the formed magnet; S40. Bending: Bend the two terminals of the coil to form, and make them fit on the magnet to form electrodes.

2. The forming method of an inductor according to claim 1, characterized in that, the step S20 includes the following steps: S21. Place the coil in the cavity (10) of the forming mold, cover the upper mold (20) of the forming mold on the lower mold (30) of the forming mold, and fix the two terminals; S22. Provide the magnetic glue (100) to the feeding position of the forming mold, heat the magnetic glue (100) at the feeding position to soften the magnetic glue (100) into a magnetic glue fluid; S23. Inject the magnetic glue fluid into the cavity (10) through the injection channel of the forming mold, so that the magnetic glue fluid coats the coil and fills the cavity (10); S24. Heat the magnetic glue fluid in the cavity (10) to cure and form the magnet.

3. The forming method of an inductor according to claim 2, characterized in that, when heating the magnetic glue (100) at the feeding position in the step S22, the temperature is T1 and the time is t1, 80°C ≤ T1 ≤ 120°C, 1 min ≤ t1 ≤ 3 min.

4. The forming method of an inductor according to claim 2, characterized in that, when heating the magnetic glue fluid in the cavity (10) in the step S24, the temperature is T2 and the time is t2, 160°C ≤ T2 ≤ 180°C, 1 min ≤ t2 ≤ 3 min.

5. The forming method of an inductor according to any one of claims 1-4, characterized in that, the magnetic glue (100) includes magnetic powder and a colloid, and the colloid coats the magnetic powder.

6. The forming method of an inductor according to claim 5, characterized in that, the particle size of the magnetic powder is A, and the initial magnetic permeability of the magnetic powder is UI, 60 mesh ≤ A ≤ 300 mesh; 20 ≤ UI ≤ 40.

7. The forming method of an inductor according to claim 5, characterized in that, the magnetic powder is at least one of alloy iron powder, carbonyl iron powder, amorphous powder, and nanocrystalline powder.

8. The forming method of an inductor according to claim 5, characterized in that, the colloid includes thermosetting glue, thermoplastic glue, and lubricant.

9. The forming method of an inductor according to any one of claims 1-4, characterized in that, when heating and baking the formed magnet in the step S30, the temperature is T3 and the time is t3, 160°C ≤ T3 ≤ 180°C, 60 min ≤ t2 ≤ 400 min.

10. An inductor, characterized in that, Manufactured by using the inductor forming method according to any one of claims 1-9, the inductor includes a magnet, a coil, and two terminals. The coil is disposed within the magnet, and the two terminals are connected to the leads at both ends of the coil. The terminals pass through the magnet and are disposed in contact with the magnet.

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