Combined inductor and manufacturing method and application thereof

Abstract

The invention belongs to the technical field of inductors, and particularly relates to a combined inductor and a manufacturing method and application thereof. The combined inductor comprises the first inductor and the second inductor which are arranged in parallel, two pins are led out of a winding conductor of each inductor from the interior of a magnet, and the led-out pins can serve as electrodes, so that a traditional metal lead frame is not needed, welding spots are reduced, the open circuit risk caused by the metal lead frame is avoided, and the service life of the inductor is prolonged. Therefore, the combined inductor has high reliability. Meanwhile, the two inductors provide four pins, and any three pins can be mutually balanced in mechanics, so that the combined inductor has good mechanical structure stability.

Description

Technical Field

[0001] This invention belongs to the field of inductor technology, and particularly relates to a combined inductor, its manufacturing method, and its application. Background Technology

[0002] Common molded inductors typically feature metal sheet electrodes (i.e., leadframes). The leadframes are interconnected with the enameled wires leading from the winding conductors within the molded inductor via a soldering process, and the molded inductor is soldered to the PCB board or other equipment through these leadframes. Due to the numerous solder joints, the risk of open circuits caused by poor soldering is unavoidable during the soldering process; simultaneously, insufficient solder joint strength can lead to solder joint detachment during use, resulting in open circuit defects. Therefore, this structure, which incorporates leadframes into molded inductors, cannot completely eliminate the risk of open circuits. Furthermore, introducing leadframes increases raw material costs and complicates the manufacturing process, leading to increased manufacturing costs.

[0003] In addition to serving as electrodes, lead frames also provide mechanical support for molded inductors, enabling them to be stably mounted on PCBs or other equipment. Without lead frames, the mechanical stability of the molded inductor deteriorates, making it susceptible to loosening, detachment, or damage due to external forces. This can lead to circuit interruptions and disrupt the normal operation of the equipment. Summary of the Invention

[0004] The purpose of this invention is to solve the problem that using a lead frame structure in a molded inductor will cause an open circuit risk, while the lack of a lead frame structure will lead to a decrease in the stability of the mechanical structure. This invention provides a combined inductor, its manufacturing method and application. The combined inductor of this invention can meet the requirements of no open circuit risk and high reliability, and also has a stable mechanical structure.

[0005] To achieve the above objectives, the present invention adopts the following technical solution.

[0006] In a first aspect, the present invention provides a combined inductor, comprising a first inductor and a second inductor arranged in parallel;

[0007] The first inductor includes a first magnet and a first winding conductor disposed inside the first magnet; the first magnet has an adjacent first surface and a second surface; the first winding conductor leads out two first pins from inside the first magnet, and the two first pins are both located on the first surface of the first magnet;

[0008] The second inductor includes a second magnet and a second winding conductor disposed inside the second magnet; the second magnet has an adjacent first surface and a second surface; the second winding conductor extends two second pins from inside the second magnet, both of which are located on the first surface of the second magnet;

[0009] The first surface of the first magnet and the first surface of the second magnet are located on the same plane; the second surface of the first magnet and the second surface of the second magnet are bonded together; any three of the two first pins and the two second pins are not collinear.

[0010] The combined inductor of the present invention has the following beneficial effects:

[0011] This invention combines two inductors, with each inductor's winding conductor having two leads extending from inside the magnet. These leads can serve as electrodes, eliminating the need for traditional metal lead frames, reducing solder joints, and avoiding the open-circuit risk caused by metal lead frames. This results in highly reliable combined inductors.

[0012] Meanwhile, the two inductors provide four pins, and any three pins can be mechanically balanced with each other, giving the combined inductor excellent mechanical structural stability. This eliminates the need to use adhesive to fix the inductor electrodes. Furthermore, after the combined inductor is soldered to the PCB board or other equipment through these four electrodes, four solder joints are formed, and any three of these solder joints can be mechanically balanced with each other. They are not easily loosened, detached, or damaged when subjected to external forces, further enhancing the stability and reliability of the combined inductor.

[0013] Furthermore, by bonding the two inductors together through their respective second surfaces, electromagnetic interference between them can be avoided, maintaining their respective good electromagnetic performance. Since traditional metal lead frames are not required, costs can be reduced.

[0014] In some embodiments, any one of the first pins has a single-line structure or a broken-line structure. The broken-line structure can be a double-broken-line structure or a triple-broken-line structure. That is, two first pins can be bent so that any one of the first pins changes from a single line to a double line or a triple line.

[0015] Similarly, any second pin can have a single-line structure or a broken-line structure. This broken-line structure can be a double-broken-line structure or a triple-broken-line structure. That is, two second pins can be bent so that any one of the second pins changes from a single line to a double or triple line.

[0016] The pins can be either single-wire or zigzag-wire. By designing the pins as zigzag-wire, the current-carrying capacity of the combined inductor can be guaranteed, while the electrode surface area can be increased, thereby improving the soldering strength between the electrodes of the combined inductor and the pads of the PCB board or other devices.

[0017] In some embodiments, both first pins are bent and attached to the first surface of the first magnet. The two first pins can be bent in any direction, for example, in the same or opposite directions.

[0018] Similarly, both second pins are bent and attached to the first surface of the second magnet. The two second pins can be bent in any direction, for example, in the same or opposite directions. Furthermore, the bending directions of the two first pins and the two second pins can be the same or opposite.

[0019] By bending the leads, they can be made to adhere to the first surface of the magnet, reducing lead wobble and further improving the mechanical stability of the combined inductor. Simultaneously, the bending structure allows the leads to form a larger surface area, increasing the electrode surface area and improving the soldering strength between the electrodes of the combined inductor and the pads on the PCB board or other devices.

[0020] In some embodiments, the first magnet and the second magnet are each independently a soft magnet. For example, at least one of the following: iron-silicon-chromium (FeSiCr) magnet, carbonyl magnet, amorphous magnet, iron-silicon-aluminum magnet, iron-silicon magnet, and iron-nickel-molybdenum magnet. The first magnet and the second magnet may be the same or different from each other.

[0021] In some embodiments, the second surface of the first magnet and the second surface of the second magnet are bonded together with adhesive. The adhesive may be an epoxy resin adhesive. After bonding, a gap of 0.2–0.5 mm, for example 0.3 mm, exists between the second surfaces of the first magnet and the second magnet.

[0022] This invention utilizes adhesive to bond two inductors. The adhesive provides sufficient bonding strength while avoiding electromagnetic interference between the two inductors. Epoxy resin adhesive, in particular, possesses excellent adhesion, temperature resistance, and durability, making it suitable for bonding inductors.

[0023] Secondly, the present invention provides a method for manufacturing the above-mentioned combined inductor, comprising:

[0024] S1, Provide a first inductor and a second inductor;

[0025] The manufacturing method of the first inductor includes:

[0026] (1-1) Place the first winding conductor into the molding groove and make the two first pins of the first winding conductor extend out of the molding groove;

[0027] (1-2) First magnetic powder is added to the molding groove for die casting. After die casting, the first magnetic powder forms a first magnet. The first magnet has an adjacent first surface and a second surface, and the two first pins are located on the first surface of the first magnet.

[0028] The methods for manufacturing the second inductor include:

[0029] (2-1) Place the second winding conductor into the molding groove and make the two second pins of the second winding conductor extend out of the molding groove;

[0030] (2-2) Add the second magnetic powder to the molding groove for die casting. The second magnetic powder forms a second magnet after die casting. The second magnet has an adjacent first surface and a second surface. Both second pins are located on the first surface of the second magnet.

[0031] S2. Bond the second surface of the first magnet to the second surface of the second magnet together, and make the first surface of the first magnet and the first surface of the second magnet lie on the same plane, and any three of the two first pins and the two second pins are not collinear.

[0032] In some embodiments, before step (1-1) or after step (1-2), the method further includes: bending the two first pins of the first winding conductor to form a zigzag structure (e.g., a double-zigzag structure or a triple-zigzag structure). The bending method includes: bending each of the two first pins once by 180° to form a double-zigzag structure. Alternatively, bending each of the two first pins twice by 180° to form a triple-zigzag structure.

[0033] Similarly, before step (2-1) or after step (2-2), the method further includes: bending the two second pins of the second winding conductor to form a zigzag structure (e.g., a double-zigzag structure or a triple-zigzag structure). The bending method includes: bending each of the two second pins once by 180°; or bending each of the two second pins twice by 180°.

[0034] In some embodiments, after steps (1-2), the method further includes bending the two first pins toward the first surface of the first magnet.

[0035] Similarly, step (2-2) also includes bending the two second pins toward the first surface of the second magnet.

[0036] In some embodiments, the first magnetic powder and the second magnetic powder each independently comprise soft magnetic powder, such as at least one of iron-silicon-chromium (FeSiCr) alloy powder, carbonyl powder, amorphous powder, iron-silicon-aluminum magnetic powder, iron-silicon magnetic powder, and iron-nickel-molybdenum magnetic powder.

[0037] In some embodiments, the method for manufacturing the first winding conductor includes: winding enameled copper wire to form the first winding conductor, stripping the insulating varnish film at the two first pin positions of the first winding conductor by laser or mechanical means, and then tinning the two first pins by a tinning process.

[0038] Similarly, the method for manufacturing the second winding conductor includes: winding enameled copper wire to form the second winding conductor, stripping the insulating varnish film at the two second pin positions of the second winding conductor by laser or mechanical means, and then tinning the two second pins by tinning process.

[0039] The tinning method employs an immersion tinning process. This process involves immersing the two first leads of the first winding conductor (or the two second leads of the second winding conductor) into molten tin for 1-3 seconds. The temperature of the molten tin is typically around 300°C. This immersion tinning process forms a uniform tin layer on the lead surface, which enhances the soldering strength between the combined inductor and the PCB board or other equipment.

[0040] In some embodiments, step S2, the method of bonding the second surface of the first magnet to the second surface of the second magnet includes: applying adhesive to at least one of the second surfaces of the first magnet and the second surface of the second magnet; and performing high-temperature treatment after bonding the second surfaces of the first magnet and the second surface of the second magnet.

[0041] The process of combining the second surface of the first magnet with the second surface of the second magnet can be carried out in a mold tool, which facilitates positioning.

[0042] The temperature and time of the high-temperature treatment can be flexibly adjusted according to the type of adhesive used. For example, for epoxy resin adhesives, it can be treated at 100-200℃ (e.g., 150℃) for 30-120 minutes.

[0043] Thirdly, the present invention provides the application of the above-mentioned combined inductor in PCB circuit boards.

[0044] Applying the combined inductor of this invention to a PCB circuit board specifically involves soldering the two first pins and two second pins of the combined inductor together with the pads of the PCB circuit board. This reduces the number of solder joints compared to traditional metal leadframes, avoiding the open-circuit risk associated with metal leadframes and improving the reliability of the PCB circuit board. Furthermore, the combined inductor of this invention exhibits excellent mechanical structural stability, which is beneficial for improving the stability of the PCB circuit board. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the structure of the first winding conductor in Example 1;

[0046] Figure 2 This is a schematic diagram of the structure of the first inductor 100 in Embodiment 1;

[0047] Figure 3 This is a bottom view of the first inductor 100 in Embodiment 1;

[0048] Figure 4 This is a front view of the combined inductor in Example 1;

[0049] Figure 5 This is a bottom view of the combined inductor in Example 1;

[0050] Figure 6 This is a left view of the combined inductor in Example 1.

[0051] Figure label:

[0052] 100 - First inductor, 110 - First magnet, 120 - First winding conductor, 121 - First pin;

[0053] 200 - Second inductor, 210 - Second magnet, 221 - Second pin. Detailed Implementation

[0054] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0055] Unless otherwise specified, the reagents, methods, and equipment used in this invention are all conventional reagents, methods, and equipment in this technical field. Corresponding technical features between the various embodiments can be combined or substituted for each other.

[0056] Example 1

[0057] A type of combined inductor, please refer to Figures 1-6 It includes a first inductor 100 and a second inductor 200 that are bonded together in parallel and symmetrically.

[0058] The first inductor 100 includes a first magnet 110 and a first winding conductor 120 disposed inside the first magnet 110, the first winding conductor 120 being integrally formed with the first magnet 110. The first magnet 100 has an approximately cuboid shape, having a bottom surface (first surface, more specifically the surface containing the length and width) and a side surface (second surface) adjacent to the bottom surface. The first winding conductor 120 extends two first pins 121 from inside the first magnet 110, both of the first pins 121 being located on the bottom surface of the first magnet 110.

[0059] Moreover, the two first pins 121 have a double-folded structure and are bent and attached to the bottom surface of the first magnet 110.

[0060] The structure of the second inductor 200 is the same as that of the first inductor 100. Specifically, the second inductor 200 includes a second magnet 210 and a second winding conductor disposed inside the second magnet 210, the second winding conductor being integrally formed with the second magnet 210. The second magnet 210 has an approximately cuboid shape (the same size as the first magnet 110), and has a bottom surface (first surface) and a side surface (second surface) adjacent to the bottom surface. The second winding conductor leads out two second pins 221 from inside the second magnet 210; both second pins 221 are located on the bottom surface of the second magnet 210.

[0061] Moreover, the two second pins 221 have a double-folded structure and are bent and attached to the bottom surface of the second magnet 210.

[0062] The bottom surface of the first magnet 110 and the bottom surface of the second magnet 210 are located on the same plane, and one side of the first magnet 110 and one side of the second magnet 210 are bonded to each other; the two first pins 121 of the first inductor 100 and the two second pins 221 of the second inductor 200 are symmetrically arranged, wherein any three of them are not collinear.

[0063] The fabrication method for a combined inductor includes the following steps:

[0064] (1) Fabricate the first inductor 100

[0065] 1) Please see Figure 1 The enameled copper wire is wound to form the first winding conductor 120. The insulating varnish film at the two first pins 121 of the first winding conductor 120 is stripped off by laser or mechanical means. Then the two first pins 121 are immersed in molten tin for 3 seconds to complete the tinning of the two first pins 121.

[0066] 2) Please see Figure 2 The two tinned first pins 121 of the first winding conductor 120 are bent 180° respectively, so that the two first pins 121 of the solder are changed from single wires to double wires. Then the first winding conductor 120 is placed in the molding groove and the two first pins 121 of the first winding conductor 120 extend out of the molding groove. First magnetic powder is added to the molding groove for die casting. After die casting, the first magnetic powder forms the first magnet 110, and the two first pins 121 are perpendicular to the bottom surface (first surface) of the first magnet 110.

[0067] The first magnetic powder is FeSiCr alloy powder.

[0068] 3) Please see Figure 3The two first pins 121, which are perpendicular to the bottom surface of the first magnet 110, are bent at 90° toward the bottom surface of the first magnet 110. The bending directions of the two first pins 121 are parallel and perpendicular to the side surface (second surface) of the first magnet 110, so that the two first pins 121 are flat against the bottom surface of the first magnet 110 to form electrodes, thus obtaining the first inductor 100.

[0069] (2) Fabricate a second inductor 200

[0070] The second inductor 200 is manufactured in the same way as the first inductor 100.

[0071] (3) Fabrication of composite inductors

[0072] Epoxy resin adhesive is applied to one side of the first inductor 100 and one side of the second inductor 200. The first inductor 100 and the second inductor 200 are positioned in a molding tool such that the bottom surface of the first magnet 110 and the bottom surface of the second magnet 210 are on the same plane, and the two first pins 121 of the first inductor 100 and the two second pins 221 of the second inductor 200 are symmetrically arranged (where no three are collinear), and the two sides of the first inductor 100 and the second inductor 200 coated with epoxy resin adhesive are joined together. Then, they are baked at 150°C to bond the two sides coated with epoxy resin adhesive together, forming a combined inductor with the first inductor 100 and the second inductor 200 symmetrically arranged side by side. Figures 4-6 As shown, where Figure 4 This is the front view of the combined inductor. Figure 5 This is a bottom view of the combined inductor. Figure 6 This is a left view of the combined inductors. There is a gap of approximately 0.3 mm between the two sides of the first inductor 100 and the second inductor 200 that are bonded together.

[0073] Example 2

[0074] A combined inductor, which differs from Embodiment 1, is that in the first inductor 100, the two first pins 121 are single-wire structures and are bent and attached to the bottom surface of the first magnet 110; at the same time, in the second inductor 200, the two second pins 221 are single-wire structures and are bent and attached to the bottom surface of the second magnet 210.

[0075] Example 3

[0076] A combined inductor differs from Embodiment 1 in that, in the first inductor 100, the two first pins 121 have a tri-fold structure and are bent and attached to the bottom surface of the first magnet 110; at the same time, in the second inductor 200, the two second pins 221 have a tri-fold structure and are bent and attached to the bottom surface of the second magnet 210.

[0077] Example 4

[0078] A combined inductor differs from Embodiment 1 in that, in the first inductor 100, the two first pins 121 are single-wire structures, not bent and attached to the bottom surface of the first magnet 110, but perpendicular to the bottom surface of the first magnet 110; at the same time, in the second inductor 200, the two second pins 221 are single-wire structures, not bent and attached to the bottom surface of the second magnet 210, but perpendicular to the bottom surface of the second magnet 210.

[0079] Comparative Example 1

[0080] An inductor, specifically the first inductor 100 of Embodiment 1. That is, in this comparative example, the first inductor 100 and the second inductor 200 are not bonded together.

[0081] Comparative Example 2

[0082] An inductor that differs from the first inductor 100 of Embodiment 1 in that it omits the double-folded structure of the two first pins 121 and is not bent and attached to the bottom surface of the first magnet 110. Instead, it adds a metal lead frame to weld the two first pins 121 together with the metal lead frame.

[0083] Specifically, the inductor in this comparative example includes a metal leadframe, a magnet, and a winding conductor disposed inside the magnet, with the winding conductor and magnet integrally formed. Two leads extend from the inside of the magnet from the winding conductor, and both leads are soldered to the metal leadframe.

[0084] Comparative Example 3

[0085] An inductor that differs from the first inductor 100 of Embodiment 1 in that two parallel first winding conductors 120 are disposed inside the first magnet 110.

[0086] Specifically, the inductor of this comparative example includes a magnet and two winding conductors disposed inside the magnet. The two winding conductors are parallel to each other (the coil portions of each winding conductor are arranged opposite each other), and the two winding conductors are integrally formed with the magnet. Each winding conductor has two leads extending from inside the magnet. The magnet has an approximately cuboid shape (twice the size of the first magnet 110 of Embodiment 1), and has a bottom surface, on which the two leads of each of the two winding conductors are located.

[0087] Furthermore, each of the two winding conductors has two pins with a double-folded structure, which are bent and attached to the bottom surface of the magnet. The four pins are symmetrically distributed on the bottom surface of the magnet.

[0088] For the combined inductors of Examples 1-4, four pins were used as electrodes and soldered onto a PCB board using a 260°C reflow soldering process. Additionally, two pins of Comparative Example 1 were soldered onto a PCB board, the metal lead frame of Comparative Example 2 was soldered onto a PCB board, and the four pins of Comparative Example 3 were soldered onto a PCB board. The open-circuit risk and mechanical structural stability of each were tested, and magnetic field coupling analysis was performed (to assess whether electromagnetic interference exists between adjacent inductors). During the testing process, 32 samples from each group were tested in parallel, and the results are shown in Table 1.

[0089] Table 1

[0090] project Opening ratio Mechanical structure (detachment) Magnetic field coupling (K) Example 1 0％ 0％ 0.18 Example 2 0％ 0％ 0.19 Example 3 0％ 0％ 0.18 Example 4 0％ 0％ 0.18 Comparative Example 1 0％ 31.2％ 0.07 Comparative Example 2 3.1％ 0％ 0.18 Comparative Example 3 0％ 0％ 0.95

[0091] (1) Risk of opening a road

[0092] Use an LCR meter to measure the inductance of a combination inductor or inductor unit. If the measured value is negative or significantly deviates from the nominal value, the inductor may be open-circuited.

[0093] The results showed that the combined inductors of Examples 1 to 4 could be tested normally with power on, and the measured values ​​did not show negative values ​​or deviate significantly from the nominal values, indicating that the products had no open circuits.

[0094] In contrast, Comparative Example 2 found that some products showed negative measurements or significant deviations from the nominal values ​​during testing, with an open circuit rate of 3.1%. Comparative Example 2 introduced a metal leadframe structure, using laser to weld copper wires to the metal leadframe. The relative position of the copper wires and the metal leadframe affected the welding effect, and this structure could not fundamentally eliminate the risk of open circuits.

[0095] (2) Mechanical structural stability

[0096] Fix the PCB circuit board on the test platform of the vibration machine, adjust the frequency (increase from 10Hz to 55Hz, then decrease to 10Hz), time (20 minutes per cycle; 12 cycles in each of the X, Y, and Z directions, for a total of 36 cycles), and amplitude (maximum amplitude is 1.5mm). Observe and record whether the product falls off the PCB circuit board or cracks appear.

[0097] The results showed that the combined inductors of Examples 1 to 4 did not detach from the PCB board during the test, the inductor products did not show cracks, and the appearance met the requirements.

[0098] While no cracks appeared in Comparative Example 1 during the test, some products (31.25%) were found to have detached from the PCB board. Comparative Example 1 did not bond the two inductors together; the isolated structure lacked mechanical stability, allowing the product to swing during vibration, leading to detachment.

[0099] (3) Magnetic field coupling analysis

[0100] According to LCR testing, the initial inductance values ​​of the first and second inductors before they were bonded together were 3.47 μH and 3.52 μH, respectively (understandably, although the first and second inductors are manufactured using the same method, slight differences in materials and operation can lead to slightly different inductance values). The initial inductance value of the combined inductor in Example 1 was 6.54 μH, and the calculated mutual inductance was 0.225 μH. Based on the coupling and mutual inductance relationship, it can be calculated that when the gap between the first and second inductors is 0.3 mm, the corresponding coupling coefficient K is 0.18, indicating that the device has low coupling.

[0101] The initial inductance values ​​of Comparative Example 3 are 2.65μH and 2.78μH respectively, and the mutual inductance Lm is 2.57μH. The coupling coefficient of the two coils inside is calculated to be 0.95. The magnetic flux generated by coil 121 and coil 221 is coupled to each other, resulting in the two coils being buried in parallel inside the magnet with a high coupling coefficient, which leads to significant electromagnetic interference.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A composite inductor, characterized in that, Includes a first inductor and a second inductor arranged in parallel; The first inductor includes a first magnet and a first winding conductor disposed inside the first magnet; the first magnet has an adjacent first surface and a second surface; the first winding conductor leads out two first pins from inside the first magnet, and both first pins are located on the first surface of the first magnet; The second inductor includes a second magnet and a second winding conductor disposed inside the second magnet; the second magnet has an adjacent first surface and a second surface; the second winding conductor leads out two second pins from inside the second magnet, and both second pins are located on the first surface of the second magnet; The first surface of the first magnet and the first surface of the second magnet are located on the same plane; the second surface of the first magnet and the second surface of the second magnet are bonded together; any three of the two first pins and the two second pins are not collinear.

2. The combined inductor according to claim 1, characterized in that, Each of the first pins has a single-line structure or a polygonal structure; And / or, either of the second pins has a single-line structure or a broken-line structure.

3. The combined inductor according to claim 2, characterized in that, The first pin has a double-segmented or triple-segmented structure. And / or, the polygonal structure of the second pin is a double polygonal structure or a triple polygonal structure.

4. The combined inductor according to any one of claims 1 to 3, characterized in that, Both first pins are bent and attached to the first surface of the first magnet; And / or, both of the second pins are bent and attached to the first surface of the second magnet.

5. The combined inductor according to any one of claims 1 to 3, characterized in that, The first magnet and the second magnet are each independently a soft magnet.

6. The combined inductor according to any one of claims 1 to 3, characterized in that, The second surface of the first magnet is bonded to the second surface of the second magnet with adhesive.

7. A method for preparing the combined inductor according to any one of claims 1 to 6, characterized in that, include: S1. Provide the first inductor and the second inductor; The method for manufacturing the first inductor includes: (1-1) Place the first winding conductor into the molding groove and make the two first pins of the first winding conductor extend out of the molding groove; (1-2) First magnetic powder is added to the molding groove for die casting; the first magnetic powder forms the first magnet after die casting, and the first magnet has an adjacent first surface and a second surface, and the two first pins are located on the first surface of the first magnet. The method for manufacturing the second inductor includes: (2-1) Place the second winding conductor into the molding groove, and make the two second pins of the second winding conductor extend out of the molding groove; (2-2) Add the second magnetic powder to the molding groove for die casting; the second magnetic powder forms the second magnet after die casting, and the second magnet has an adjacent first surface and a second surface, and the two second pins are located on the first surface of the second magnet; S2. Bond the second surface of the first magnet to the second surface of the second magnet together, and make the first surface of the first magnet and the first surface of the second magnet lie on the same plane, and any three of the two first pins and the two second pins are not collinear.

8. The method for preparing the combined inductor according to claim 7, characterized in that, Before step (1-1) or after step (1-2), the method further includes: bending the two first pins of the first winding conductor to form a zigzag structure; And / or, before step (2-1) or after step (2-2), the method further includes: bending the two second pins of the second winding conductor to form a zigzag structure.

9. The method for preparing the combined inductor according to claim 7 or 8, characterized in that, Steps (1-2) are followed by: bending the two first pins toward the first surface of the first magnet; And / or, step (2-2) further includes: bending the two second pins toward the first surface of the second magnet, respectively.

10. The application of the combined inductor according to any one of claims 1 to 6 in a PCB circuit board.

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