Solderless molded inductor

Abstract

The application discloses a no-welding-point molded inductor, which comprises a molded magnet and a flat coil embedded in the molded magnet, the flat coil is formed by the middle section of a continuous wire being wound into superimposed circles along the thickness direction of the flat coil, the two end sections of the continuous wire form wire arms which extend out of the molded magnet and are attached to the surface of the molded magnet, and the wire arms at least comprise a terminal pin section. In the no-welding-point molded inductor provided by the application, the coil embedded in the molded magnet is a flat coil, the interlayer distribution of the flat coil is more uniform, and the working efficiency of the inductor is improved; and the welding points are eliminated by using the original wire as a terminal, thereby avoiding the resistance, parasitic capacitance and inductance of the welding points, the current transmission efficiency is high, meanwhile, the welding point related problems are avoided, the internal structure is more stable, can better withstand vibration and impact, the accuracy of circuit work is ensured, and the no-welding-point molded inductor has the characteristics of excellent electrical performance, high reliability, good heat dissipation performance and high-frequency application adaptability.

Description

Technical Field

[0001] This utility model relates to the field of inductor technology, and in particular to a molded inductor without solder joints. Background Technology

[0002] In the field of inductor manufacturing technology, the traditional forming method mainly involves winding round wire around a magnetic core and then connecting the wire to the terminals using welding methods such as resistance welding, laser welding, or ultrasonic welding. Because of the large gaps between the wires during the winding process, the space utilization rate is low. This low volume utilization directly results in the current density not being evenly distributed across the wires when current passes through the inductor, leading to a significant increase in resistance and heat generation.

[0003] In high-current, high-power circuit applications, these problems become even more pronounced. On the one hand, welding processes based on resistance, laser, or ultrasonic principles are complex, increasing both the complexity of the production process and manufacturing costs. On the other hand, the presence of welded joints further increases local resistance, causing the inductor to generate excessive heat during operation. Excessive heat accelerates the aging of internal inductor materials, shortens its lifespan, reduces its efficiency, and can even lead to electrical faults, severely impacting the stability and reliability of the entire circuit system.

[0004] Therefore, it is urgent to improve the structure of traditional inductors to solve the above-mentioned technical problems. Utility Model Content

[0005] The purpose of this invention is to provide a solderless molded inductor, which solves the problems of low volume utilization and high resistance and heat generation of existing molded inductors.

[0006] The above-mentioned objectives of this utility model can be achieved by the following technical solutions:

[0007] This utility model provides a solderless molded inductor, including a molded magnet and a flat coil embedded inside the molded magnet. The flat coil is formed by winding the middle section of a continuous conductor into stacked circles along its thickness direction. The two ends of the continuous conductor form wire arms that extend out of the molded magnet and are attached to the surface of the molded magnet. The wire arms include at least terminal pin segments.

[0008] Preferably, the wire arm further includes a mechanical pin segment, and the two wire arms extend from the same surface of the molded magnet and extend in the same direction parallel across the same surface attached to the molded magnet.

[0009] In one specific embodiment, the wire arm is L-shaped, and the solderless molded inductor further includes a support pin, which is isolated from the flat coil and connected to the molded magnet.

[0010] Preferably, the support pin is disposed away from the wire arm, the support pin is U-shaped, and the opening of the support pin is disposed towards the flat coil.

[0011] Preferably, the support pin has a middle portion that is attached to the surface of the molded magnet and is disposed opposite to the wire arm.

[0012] Preferably, there are two support pins, which are arranged opposite to the two wire arms about the flat coil, or the two support pins are arranged on opposite sides of the flat coil.

[0013] Preferably, there is one support pin, which is arranged opposite to the two wire arms about the flat coil, and the width of the support pin is not less than the sum of the distance between the two wire arms and the width of the two wire arms.

[0014] In one specific embodiment, the wire arm is U-shaped, and an insulating clip covering the outside of the wire arm is connected to the surface of the molded magnet to which the end of the wire arm is attached.

[0015] In one specific embodiment, the wire arm is G-shaped, and the end of the wire arm is fixed to the surface of the molded magnet by an adhesive.

[0016] Preferably, the two wire arms extend from the same end face or different end faces of the flat coil to the molded magnet.

[0017] Preferably, the continuous conductor is a flat conductor, or the continuous conductor is formed by pressing a round conductor into a flat shape.

[0018] Preferably, the molded magnet is formed by molding magnetic powder together with the flat coil.

[0019] The features and advantages of this utility model are as follows: The molded inductor without solder joints provided by this utility model has a flat coil embedded inside the molded magnet, which has a more uniform interlayer distribution, increases the volume utilization rate of the molded inductor, and makes the current density distribution more uniform. This effectively reduces resistance and heat generation, improves the working efficiency of the inductor, and provides a new approach for the improvement of high-power and high-efficiency inductors. Furthermore, the flat coil is made from the middle section of a continuous conductor, and the two ends of the continuous conductor form wire arms that extend out and attach to the surface of the molded magnet, including at least the terminal pin segments. In this way, by using the original conductor as the terminal, the solder joint is eliminated, thereby avoiding the resistance, parasitic capacitance, and inductance of the solder joint. The current transmission efficiency is high, and the problems related to solder joints, such as the impact of solder quality on electrical performance and reliability, and the impact of solder and flux on heat dissipation performance, are avoided. Its internal structure is more stable and can better withstand vibration and impact. Its inductance value is less affected by external factors and can remain stable under different working conditions, ensuring the accuracy of circuit operation. The solderless molded inductor provided by this utility model has the characteristics of excellent electrical performance, high reliability, good heat dissipation performance, and suitability for high-frequency applications. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of a U-shaped, weld-free molded inductor with a U-shaped lead arm provided in an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of a G-shaped molded inductor without solder joints provided in an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of a solderless molded inductor provided in this embodiment of the present invention, wherein the wire arm is L-shaped and leads out from the same end face of the flat coil, and two support pins are provided on opposite sides of the flat coil.

[0024] Figure 4 The schematic diagram shows a molded inductor with L-shaped wire arms that are led out from the same end face of the flat coil and have two support pins and two wire arms that are arranged opposite to the flat coil.

[0025] Figure 5This is a schematic diagram of a molded inductor with L-shaped wire arms that are led out from different end faces of a flat coil and have two support pins and two wire arms that are arranged opposite to the flat coil.

[0026] Figure 6 The schematic diagram shows an L-shaped molded inductor provided in this embodiment of the present invention, in which the wire arms are led out from the same end face of the flat coil and have a support pin and the two wire arms are arranged opposite to each other with respect to the flat coil.

[0027] Explanation of icon numbers:

[0028] 1. Molded magnets;

[0029] 2. Flat coil;

[0030] 3. Line arm;

[0031] 4. Support pins;

[0032] 5. Insulating clamp. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0034] like Figures 1 to 6 As shown, this utility model provides a solderless molded inductor, including a molded magnet 1 and a flat coil 2 embedded inside the molded magnet 1. The flat coil 2 is formed by winding the middle section of a continuous conductor into stacked circles along its thickness direction. The two ends of the continuous conductor form wire arms 3 that extend out of the molded magnet 1 and are attached to the surface of the molded magnet 1. The wire arms 3 include at least terminal pin segments for soldering to the pad patterns on the PCB. The molded magnet 1 is rectangular. The wire arms 3 can be directly bent and attached to the surface of the molded magnet 1, or they can be bent and coated with epoxy resin, hot melt adhesive, or other adhesives to ensure the rigidity of the wire arms 3. The specific choice can be adapted according to the size of the wire arms 3 and the requirements for attachment reliability.

[0035] The solderless molded inductor provided by this invention features a flat coil 2 embedded inside the molded magnet 1. This flat coil has a more uniform interlayer distribution, increasing the volume utilization of the molded inductor and enabling a more uniform current density distribution. This effectively reduces resistance and heat generation, improving the inductor's efficiency and providing a new approach for improving high-power and high-efficiency inductors. Furthermore, the flat coil 2 is made from the middle section of a continuous conductor, with both ends forming wire arms 3 extending from and attached to the surface of the molded magnet 1, including at least terminal pin segments. By using the original conductor as terminals, solder joints are eliminated, thus avoiding the resistance, parasitic capacitance, and inductance associated with solder joints. This results in high current transmission efficiency and avoids problems related to solder joints, such as the impact of solder quality on electrical performance and reliability, and the influence of solder and flux on heat dissipation. The internal structure is more robust, better able to withstand vibration and impact, and its inductance value is less affected by external factors, remaining stable under different operating conditions and ensuring the accuracy of circuit operation. The solderless molded inductor provided by this invention features excellent electrical performance, high reliability, good heat dissipation, and suitability for high-frequency applications.

[0036] According to one embodiment of the present invention, such as Figure 4 and Figure 5 As shown, two wire arms 3 lead out molded magnets 1 from the same end face or different end faces of the flat coil 2 to adapt to different circuit wiring requirements.

[0037] According to one embodiment of this utility model, the continuous conductor is a flat wire, or the continuous conductor is formed by pressing a round wire into a flat shape. Thus, as... Figures 1 to 6 As shown, the flat coil 2 and the wire arm 3 are an integrated flat structure with a large conductive area, which significantly improves the current carrying capacity of the inductor and makes it suitable for high current scenarios. At the same time, the flat structure of the coil is not easily deformed during the molding process, and the flat structure of the wire arm 3 is easier to bend and attach to the surface of the molded magnet 1. It also helps to ensure the coplanarity of the terminal pin segments, making it easier to solder to the PCB pad pattern.

[0038] According to one embodiment of the present invention, the molded magnet 1 is formed by molding magnetic powder together with a flat coil 2. Preferably, the magnetic powder used for molding is a mixed magnetic powder made of high-permeability powder and low-permeability powder in a preset ratio to obtain better inductance performance.

[0039] According to one embodiment of this utility model, the wire arm 3 further includes a mechanical pin segment, which is formed by extending the wire arm 3 to attach to the surface of the molded magnet 1, thereby enhancing the structural stability of the inductor. Figures 1 to 6As shown, two wire arms 3 extend from the same surface of the molded magnet 1 and extend in the same direction across the same surface of the molded magnet 1. In this way, the two wire arms 3 extending out of the molded magnet 1 in the extended state can be bent synchronously to form the final state of the wire arms 3, thereby simplifying the processing technology and ensuring the flatness of the two wire arms 3.

[0040] According to a preferred embodiment of the present invention, such as Figure 1 As shown, the two wire arms 3 are U-shaped, meaning they extend parallel to the protruding surfaces of the molded magnet 1 in a clockwise or counterclockwise direction, spanning and attaching to the three common surfaces of the molded magnet 1. This provides a longer mechanical lead segment, ensuring better structural stability of the inductor. An insulating clip 5, covering the outside of the wire arm 3, is attached to the surface of the molded magnet 1 at the end of the wire arm 3 to fix it and strengthen its structural strength. Preferably, the insulating clip 5 is a plastic clip to achieve inductor weight reduction.

[0041] According to a preferred embodiment of the present invention, such as Figure 2 As shown, the two wire arms 3 are G-shaped, meaning they extend parallel to each other from the protruding surface of the molded magnet 1 in a clockwise or counterclockwise direction, spanning and attaching to the four common surfaces of the molded magnet 1. This further extends the mechanical lead section, allowing the inductor to achieve both better structural stability and mechanical performance. The ends of the wire arms 3 are fixed to the surface of the molded magnet 1 with adhesive to secure the wire arms 3 and strengthen their connection. Whether or not adhesive fixation is required at the ends of the wire arms 3 can be selected adaptively based on the inductor's operating conditions.

[0042] According to a preferred embodiment of the present invention, such as Figures 3 to 6 As shown, the two wire arms 3 are L-shaped, meaning they extend parallel to each other from the protruding surface of the molded magnet 1 in a clockwise or counterclockwise direction, crossing and attaching to the two common surfaces of the molded magnet 1. The molded inductor without solder joints also includes support pins 4, which are isolated from the flat coil 2 and connected to the molded magnet 1. In this embodiment, because the wire arms 3 are L-shaped, their mechanical pin segments are too short, limiting their ability to enhance the structural stability of the inductor. By providing separate support pins 4, the structural stability of the inductor is further enhanced.

[0043] It should be noted that, among the three embodiments described above, the inductor with L-shaped wire arm 3 has the simplest processing technology. The wire arm 3, which is in an extended state, can be automatically bent in the same direction along the surface of the molded magnet 1 during the molding process due to the mold limit, forming the final state of the wire arm 3. The wire arm 3 can be fixedly attached to the molded magnet 1 by spraying glue.

[0044] According to one embodiment of the present invention, such as Figures 3 to 6As shown, the support pin 4 is positioned away from the wire arm 3 to achieve physical isolation. The support pin 4 is U-shaped, with its opening facing the flat coil 2, ensuring sufficient contact area between the support pin 4 and the molded magnet 1 for better support reinforcement. Preferably, the flatness between the flange of the support pin 4, which is coplanar with the wire arm 3, and the wire arm 3 is no greater than 0.1 mm, to facilitate inductor mounting and inductor miniaturization. Furthermore, the flange end of the support pin 4, which is coplanar with the segment of the wire arm 3 extending from the flat coil 2, has an arc-shaped structure, so that the support pin 4, while isolated from the flat coil 2, obtains a larger contact area with the molded magnet 1, further enhancing the support reinforcement effect.

[0045] According to one embodiment of the present invention, the support pin 4 has a middle part, which is attached to the surface of the molded magnet 1 and disposed opposite to the wire arm 3, so that the inductor obtains better mechanical performance.

[0046] According to one embodiment of this utility model, the support pin 4 is two, such as... Figure 4 and Figure 5 As shown, the two support pins 4 and the two wire arms 3 are positioned opposite each other about the flat coil 2, or, as... Figure 3 As shown, the two support pins 4 are located on opposite sides of the flat coil 2, and the specific selection depends on the operating conditions of the inductor.

[0047] According to one embodiment of the present invention, such as Figure 6 As shown, there is one support pin 4, which is positioned opposite to the two wire arms 3 about the flat coil 2. The width of the support pin 4 is not less than the sum of the distance between the two wire arms 3 and the width of the two wire arms 3. This further increases the contact area between the support pin 4 and the molded magnet 1, improves the support reinforcement effect, and gives the inductor better vibration resistance.

[0048] The inductance of a solderless molded inductor is calculated using the following formula: L = μ0μ i N 2 A e / L e Where L represents the inductance, μ0 represents the free permeability of the coated magnet, and μ i The initial permeability of the coated magnet is represented by N, and the number of turns of the flat coil 2 is represented by A. e L represents the equivalent cross-sectional area of ​​flat coil 2. e The equivalent magnetic circuit length of flat coil 2 is represented; the formula for calculating the saturation current of the solderless molded inductor is as follows: I sat ≈K / ρDμ i N; where I sat The saturation current is represented by K, a constant, ρ is the density of the coated magnet, D is the particle size of the coated magnet powder, and μ is the density of the coated magnet.i The initial permeability of the coated magnet is represented by , and N represents the number of turns of the flat coil 2.

[0049] The above descriptions are merely a few embodiments of this utility model. Those skilled in the art can make various modifications or variations to the embodiments of this utility model based on the content disclosed in the application documents without departing from the spirit and scope of this utility model.

Claims

1. A solderless molded inductor, characterized in that, The device includes a molded magnet and a flat coil embedded inside the molded magnet. The flat coil is formed by winding the middle section of a continuous conductor into overlapping circles along its thickness direction. The two ends of the continuous conductor form wire arms that extend out of the molded magnet and are attached to the surface of the molded magnet. The wire arms include at least terminal pin segments.

2. The solderless molded inductor according to claim 1, characterized in that, The wire arm also includes a mechanical pin segment, and the two wire arms extend from the same surface of the molded magnet and extend in the same direction and parallel across the same surface attached to the molded magnet.

3. The solderless molded inductor according to claim 2, characterized in that, The wire arm is L-shaped, and the solderless molded inductor also includes a support pin, which is isolated from the flat coil and connected to the molded magnet.

4. The solderless molded inductor according to claim 3, characterized in that, The support pin is positioned away from the wire arm, the support pin is U-shaped, and the opening of the support pin faces the flat coil.

5. The solderless molded inductor according to claim 4, characterized in that, The support pin has a middle portion that is attached to the surface of the molded magnet and is disposed opposite to the wire arm.

6. The solderless molded inductor according to claim 5, characterized in that, There are two support pins, which are arranged opposite to the two wire arms about the flat coil, or the two support pins are arranged on opposite sides of the flat coil.

7. The solderless molded inductor according to claim 5, characterized in that, There is one support pin, which is arranged opposite to the two wire arms about the flat coil. The width of the support pin is not less than the sum of the distance between the two wire arms and the width of the two wire arms.

8. The solderless molded inductor according to claim 2, characterized in that, The wire arm is U-shaped, and an insulating clip covering the outside of the wire arm is connected to the surface of the molded magnet attached to the end of the wire arm.

9. The solderless molded inductor according to claim 2, characterized in that, The wire arm is G-shaped, and the end of the wire arm is fixed to the surface of the molded magnet by adhesive.

10. The solderless molded inductor according to claim 1, characterized in that, The two wire arms are drawn from the same end face or different end faces of the flat coil to form the molded magnet.

11. The solderless molded inductor according to claim 1, characterized in that, The continuous conductor is a flat wire, or the continuous conductor is formed by pressing a round wire into a flat shape.

12. The solderless molded inductor according to claim 1, characterized in that, The molded magnet is formed by molding magnetic powder together with the flat coil.

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