Plastic package type magnetic device and preparation method thereof

Abstract

The invention relates to the technical field of magnetic devices, and discloses a plastic package type magnetic device and a preparation method thereof, the preparation method of the plastic package type magnetic device comprises the following steps: pressing partially laminated coils to form a first winding, the outer surface of the first winding being provided with a plurality of first thimble positioning areas; carrying out primary injection molding on the first winding by adopting an injection molding material to form a first sealing colloid, wherein the first sealing colloid wraps or partially wraps the area, except the first ejector pin positioning area, of the first winding; the coil with the laminated part forms a second winding, and the outer surface of the second winding is provided with a plurality of second ejector pin positioning areas; performing primary injection molding on the second winding by adopting an injection molding material to form a second sealing colloid, wherein the second sealing colloid wraps or partially wraps the first sealing colloid and wraps or partially wraps an area, except the second ejector pin positioning area, of the second winding; and the first winding and the second winding are assembled in the accommodating cavity of the magnetic core main body. The reliability of the device is improved.

Description

Technical Field

[0001] The present application relates to the technical field of magnetic devices, and in particular to a plastic-encapsulated magnetic device and a preparation method thereof. Background Art

[0002] Magnetic devices are key electronic components that use the principle of electromagnetic induction to achieve energy conversion, transmission and storage. They are widely used in power management, signal processing, electromagnetic compatibility and other fields, including transformers, inductors, etc. The specific structure may include magnetic cores, coils, skeletons, terminals and packaging, etc. Magnetic devices in related technologies, with the development of the electronics industry, the application voltage of products is getting higher and higher. Taking transformer products as an example, the insulation of the product mainly relies on wire insulation layer and tape insulation, resulting in insufficient insulation capacity. In high-voltage and high-frequency environments, the temperature of the product rises and local discharge is serious, affecting the reliability of the device. This situation needs to be changed. Summary of the invention

[0003] In view of this, the present application provides a plastic-encapsulated magnetic device and a preparation method thereof to solve the above-mentioned technical problems.

[0004] To achieve the above objectives, according to the first aspect, the technical solution adopted is:

[0005] A method for preparing a plastic-encapsulated magnetic device, comprising:

[0006] Providing a plurality of coils, wherein the coils are pressed and partially stacked to form a first winding, and the outer surface of the first winding has a plurality of first ejector pin positioning areas;

[0007] Performing one injection molding on the first winding using an injection molding material to form a first sealing body, wherein the first sealing body wraps or partially wraps an area of ​​the first winding except the first ejector pin positioning area;

[0008] The partially stacked coils are pressed onto the first sealing body to form a second winding, and the outer surface of the second winding has a plurality of second ejector pin positioning areas;

[0009] The second winding is once injection molded with the injection molding material to form a second sealing body, wherein the second sealing body wraps or partially wraps the first sealing body and wraps or partially wraps the area of ​​the second winding except the second ejector positioning area;

[0010] The first winding and the second winding are assembled in the accommodating cavity of the magnetic core body.

[0011] The present application is further configured as follows: before assembling the first winding and the second winding in the accommodating cavity of the magnetic core body, the method further includes:

[0012] The second sealing body is injection-molded at least once using the injection molding material to form a sealing body, and the sealing body wraps the second sealing body, the second winding, the first sealing body and the first winding.

[0013] The present application is further configured as follows: before assembling the first winding and the second winding in the accommodating cavity of the magnetic core body, the method further includes:

[0014] The partially stacked coils are pressed onto the second sealing body to form an extended winding, and the outer surface of the stacked and pressed extended winding has a plurality of extended ejector pin positioning areas;

[0015] The extended winding is once injection molded with the injection molding material to form an extended encapsulation body, wherein the extended encapsulation body wraps or partially wraps the second encapsulation body and wraps or partially wraps the area of ​​the extended winding except the extended ejector pin positioning area.

[0016] The present application is further configured as follows: a magnetic column is provided in the accommodating cavity of the magnetic core body, the first winding and the second winding are sleeved and connected on the magnetic column, the first winding has a first lead end, the second winding has a second lead end, and the first lead end and the second lead end extend toward each other outside the magnetic core body.

[0017] The present application is further configured as follows: a plurality of first ejector pin positioning areas are evenly arranged on the outer surface of the first winding, and a plurality of second ejector pin positioning areas are evenly arranged on the outer surface of the second winding, wherein the first ejector pin positioning areas and the second ejector pin positioning areas are not in the same position relative to the vertical projection area of ​​the magnetic core body.

[0018] The present application is further configured as follows: there is a pressing gap between adjacent coils in the first winding and the second winding, and the pressing gap is ≤10% of the thickness of the coil.

[0019] The present application is further configured as follows: an area covered by the first sealing compound on the first winding is ≥ 10% of a surface area of ​​the first winding, and an area covered by the second sealing compound on the second winding is ≥ 10% of a surface area of ​​the second winding.

[0020] The present application is further configured as follows: a thickness of the first sealing glue body and / or the second sealing glue body is ≥ 0.3 mm.

[0021] The present application is further configured as follows: the injection molding material includes at least one of polyethylene terephthalate, acrylonitrile-butadiene-styrene copolymer, polyamide or polycarbonate, and the injection molding materials of the first encapsulating body and the second encapsulating body are different.

[0022] According to the second aspect, the technical solution adopted is:

[0023] A plastic-encapsulated magnetic device is manufactured by applying the method for manufacturing a plastic-encapsulated magnetic device described in any of the above embodiments, comprising:

[0024] A magnetic core body, wherein a receiving cavity is provided in the magnetic core body;

[0025] A plurality of coils, some of which are stacked and pressed together to form a first winding, wherein the outer surface of the first winding has a plurality of first ejector pin positioning areas;

[0026] A first sealing body, wherein the first sealing body wraps or partially wraps an area of ​​the first winding except the first ejector pin positioning area, the partially stacked coils pressed on the first sealing body form a second winding, and the outer surface of the second winding has a plurality of second ejector pin positioning areas;

[0027] a second sealing body, wherein the second sealing body wraps or partially wraps the first sealing body, and wraps or partially wraps an area of ​​the second winding except the second ejector positioning area;

[0028] Wherein, the first winding and the second winding are connected in the accommodating cavity.

[0029] In summary, compared with the prior art, the present application discloses a plastic-encapsulated magnetic device and a preparation method thereof, wherein the first winding is formed by pressing together partially stacked coils and has a plurality of first ejector pin positioning areas, after the first winding is once injection-molded with an injection molding material to form a first sealing body, the first sealing body wraps or partially wraps the area of ​​the first winding except the first ejector pin positioning area, and the partially stacked coils are pressed together on the first sealing body to form a second winding, the outer surface of the second winding has a plurality of second ejector pin positioning areas, after the second winding is once injection-molded with an injection molding material to form a second sealing body, the second sealing body wraps or partially wraps the first sealing body, and wraps or partially wraps the area of ​​the second winding except the second ejector pin positioning area, and the first winding and the second winding are assembled in the accommodating cavity of the magnetic core body, that is, through the above arrangement, the first winding and the second winding of the plastic-encapsulated magnetic device are wrapped by the first sealing body and the second sealing body by one-time injection molding, that is, the windings are integrated and insulated, thereby improving the mechanical stability and insulation capacity of the magnetic device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 is a process flow chart of the method for preparing a plastic-encapsulated magnetic device of this embodiment;

[0032] Figure 2 is a schematic structural diagram of a first plastic-encapsulated magnetic device of this embodiment;

[0033] Figure 3 is a schematic structural diagram of a second plastic-encapsulated magnetic device of this embodiment;

[0034] Figure 4 is a schematic structural diagram of a third plastic-encapsulated magnetic device of this embodiment;

[0035] Figure 5 is a schematic structural diagram of a fourth plastic-encapsulated magnetic device of this embodiment;

[0036] Figure 6 is a schematic structural diagram of a fifth plastic-encapsulated magnetic device of this embodiment;

[0037] Figure 7 is a schematic structural diagram of a sixth plastic-encapsulated magnetic device of this embodiment;

[0038] Figure 8 4 is a schematic diagram of the structure of the seventh plastic-encapsulated magnetic device of this embodiment. DETAILED DESCRIPTION

[0039] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0040] It should be noted that, in this article, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element. In addition, components, features, and elements with the same name in different embodiments of the present application may have the same meaning or different meanings, and their specific meanings need to be determined by their explanation in the specific embodiment or further combined with the context of the specific embodiment.

[0041] It should be further understood that the terms "comprising" and "including" indicate the presence of the described features, steps, operations, elements, components, items, kinds, and / or groups, but do not exclude the presence, occurrence or addition of one or more other features, steps, operations, elements, components, items, kinds, and / or groups. The terms "or", "and / or", "including at least one of the following", etc. used in this application may be interpreted as inclusive, or mean any one or any combination. For example, "including at least one of the following: A, B, C" means "any one of the following: A; B; C; A and B; A and C; B and C; A and B and C", and for another example, "A, B or C" or "A, B and / or C" means "any one of the following: A; B; C; A and B; A and C; B and C; A and B and C". Exceptions to this definition will only occur when the combination of elements, functions, steps or operations is inherently mutually exclusive in some way.

[0042] It should be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this document, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, as used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless otherwise indicated in the context.

[0043] It should be understood that the orientations or positional relationships indicated by terms such as "top", "bottom", "up", "down", "vertical", and "horizontal" are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description. They do not indicate or imply that the device referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0044] For ease of description, in the following embodiments, the orthogonal space formed by the horizontal plane and the vertical direction is used as an example for explanation, and this premise should not be understood as a limitation to the present application.

[0045] Please refer to Figure 1 , Figure 1 : is a process flow chart of the method for preparing a plastic-encapsulated magnetic device of this embodiment. The method for preparing a plastic-encapsulated magnetic device of this application comprises:

[0046] S101 , providing a plurality of coils 1 , pressing and assembling partially stacked coils 1 to form a first winding 2 , wherein the outer surface of the first winding 2 has a plurality of first ejector pin positioning areas 3 .

[0047] In this step, refer to Figure 2 and Figure 3The first winding 2 is formed by pressing together some of the stacked coils 1. Specifically, the mold ejector can act on some of the stacked coils 1, thereby pressing together the gaps between the coils 1, compressing the space of the coils 1, and obtaining a first winding 2 with a smaller volume. The outer surface of the first winding 2 has a plurality of first ejector positioning areas 3. The first ejector positioning areas 3 can be regarded as the area where the mold ejector acts on the coil 1, and the first ejector positioning areas 3 can also be used as the alignment points for the subsequent one-time injection molding, thereby ensuring that the first winding 2 is pressed evenly.

[0048] In one embodiment, the first ejector pin positioning area 3 of the first winding 2 may be marked by a color.

[0049] S102 , performing a first injection molding on the first winding 2 using an injection molding material to form a first encapsulating body 4 , wherein the first encapsulating body 4 wraps or partially wraps an area of ​​the first winding 2 except the first ejector pin positioning area 3 .

[0050] In this step, continue to combine Figure 3 The first encapsulating body 4 serves as an insulator and is wrapped or partially wrapped on the first winding 2 by one-time injection molding of the injection molding material, thereby fixing the coil 1 of the first winding 2 and forming a good insulation isolation structure on the first winding 2.

[0051] It is understandable that the first ejector pin positioning area 3, as the action point of the aforementioned mold ejector, is not wrapped by the first sealing gel 4. At the same time, the wrapping and plastic sealing effect of the first winding 2 can also be observed through the first ejector pin positioning area 3 to ensure the reliability of the winding structure.

[0052] S103 , partially laminating the coils 1 on the first encapsulation body 4 to form a second winding 5 , and the outer surface of the second winding 5 has a plurality of second ejector pin positioning areas 6 .

[0053] In this step, refer to Figure 4 and Figure 5 The second winding 5 can be formed by pressing and laminating the partial coils 1 stacked on the first encapsulating body 4, thereby pressing and closing the gaps between the coils 1 on the first encapsulating body 4 to obtain a second winding 5 with a smaller volume, wherein the outer surface of the second winding 5 has a plurality of second ejector pin positioning areas 6, and the second ejector pin positioning areas 6 can be regarded as the area where the mold ejector acts on the coil 1 on the first encapsulating body 4, and the second ejector pin positioning areas 6 can also be used as the alignment points for the subsequent one-time injection molding.

[0054] The second winding 5 of the present application is formed on the first sealing body 4, and the first sealing body 4 can effectively isolate the first winding 2 and the second winding 5, ensure the insulation energy resistance effect between the two, and avoid partial discharge during normal operation of the device.

[0055] In one embodiment, a partial coil 1 can be set on one side of the first sealing body 4, or on both sides of the first sealing body 4. That is to say, the second winding 5 can be arranged in sequence with the first winding 2, or the first winding 2 can be clamped symmetrically. This can be specifically set based on environmental requirements and product performance requirements.

[0056] S104 , performing a first injection molding on the second winding 5 with an injection molding material to form a second encapsulating body 7 , wherein the second encapsulating body 7 wraps or partially wraps the first encapsulating body 4 , and wraps or partially wraps the area of ​​the second winding 5 except the second ejector positioning area 6 .

[0057] In this step, continue to combine Figure 5 The second sealing body 7 serves as an insulator, and wraps or partially wraps the first sealing body 4 and the area of ​​the second winding 5 except the second ejector positioning area 6 through one-time injection molding of the injection molding material, thereby fixing the coil 1 of the second winding 5 and forming a good insulation isolation structure on the second winding 5.

[0058] It is understandable that the second ejector pin positioning area 6, as the action point of the aforementioned mold ejector, is not wrapped by the second sealing glue 7. At the same time, the wrapping and plastic sealing effect of the second winding 5 can also be observed through the second ejector pin positioning area 6 to ensure the reliability of the winding structure.

[0059] Then, the second sealing body 7 acts on the second winding 5 and the first sealing body 4 in the form of one-time injection molding of the injection molding material, thereby ensuring the insulation resistance effect between the first winding 2 and the second winding 5, and between the second winding 5 and the outside world, avoiding local discharge during normal operation of the device, that is, improving the insulation capacity and structural strength of the magnetic device, and the first winding 2 and the second winding 5 formed by pressing also meet the miniaturization requirements of the magnetic device.

[0060] In one embodiment, in combination Figure 5 and Figure 6 After the second sealing body 7 is formed, the second sealing body 7 can be injection molded at least once with an injection molding material to form a sealing body 10. The sealing body 10 wraps the second sealing body 7, the second winding 5, the first sealing body 4 and the first winding 2, thereby further improving the insulation withstand voltage capability and structural strength of the magnetic device.

[0061] S105 , assembling the first winding 2 and the second winding 5 in the accommodating cavity 9 of the magnetic core body 8 .

[0062] In this step, refer to Figure 7 and Figure 8The first winding 2 and the second winding 5 are assembled in the accommodating cavity 9 of the magnetic core body 8 to complete the combination of the winding and the magnetic core of the device, and the magnetic core body 8 matches the first winding 2 and the second winding 5 through the accommodating cavity 9 opened inside, thereby ensuring the stability of the structure.

[0063] Among them, the accommodating cavity 9 of the magnetic core body 8 is provided with a magnetic column 13, the first winding 2 and the second winding 5 are sleeved and connected on the magnetic column 13, and the first winding 2 has a first lead end 14, the second winding 5 has a second lead end 15, the first lead end 14 and the second lead end 15 extend toward each other outside the magnetic core body 8, that is, the first lead end 14 and the second lead end 15 can be used as connection terminals of the magnetic device for electrical connection with the outside world respectively. At the same time, the magnetic column 13 can also cooperate to fix the first winding 2 and the second winding 5. Based on the design of the aforementioned first sealing body 4 and the second sealing body 7, the second sealing body 7 can be attached to the magnetic column 13 or maintain a gap with the magnetic column 13.

[0064] In one embodiment, continue to combine Figure 5 and Figure 6 Before assembling the first winding 2 and the second winding 5 in the accommodating cavity 9 of the magnetic core body 8, a partially stacked coil 1 can be pressed on the second sealing body 7 to form an extended winding 11, wherein the outer surface of the stacked and pressed extended winding 11 has a plurality of extended ejector pin positioning areas. Similarly, the mold ejector can act on the stacked coil 1 on the second sealing body 7, and the extended winding 11 is once injection molded with an injection molding material to form an extended sealing body 12, and the extended sealing body 12 wraps or partially wraps the second sealing body 7, and wraps or partially wraps the area of ​​the extended winding 11 except the extended ejector pin positioning area.

[0065] That is, the magnetic device of the present application is not limited to the assembly form of the first winding 2 and the second winding 5. Based on environmental requirements and product performance requirements, the device function can be enriched by extending the winding 11, and the insulation effect between the extended winding 11 and the second winding 5, and between the extended winding 11 and the outside world can be ensured by extending the sealing body 12, thereby improving the insulation capacity and structural strength of the magnetic device.

[0066] That is to say, based on the process form of the aforementioned first sealing body 4 and the second sealing body 7, the present application can continue to stack the third winding and the third sealing body, the fourth winding and the fourth sealing body, and the fifth winding and the fifth sealing body, etc., which will not be repeated here.

[0067] It should be noted that, in the present application, multiple first ejector positioning areas 3 are evenly arranged on the outer surface of the first winding 2, and multiple second ejector positioning areas 6 are evenly arranged on the outer surface of the second winding 5, wherein the vertical projection areas of the first ejector positioning area 3 and the second ejector positioning area 6 relative to the magnetic core body 8 are not in the same position, that is, the vertical projection areas of the first ejector positioning area 3 and the second ejector positioning area 6 relative to the magnetic core body 8 do not overlap. As a result, the areas where the ejector pins of the stacked and pressed first winding 2 and second winding 5 apply pressure are staggered, avoiding the problem of pressure concentration caused by the ejector pins acting on the same position of the winding at the same time, improving the reliability of the device, and also helping to make the overall compression of the first winding 2 and the second winding 5 more uniform, ensuring that the magnetic device has a smaller winding volume, thereby improving the overall performance of the magnetic device.

[0068] The first winding 2 and the second winding 5 of the present application are formed by pressing together partially stacked coils 1, wherein there is a pressing gap between adjacent coils 1 in the first winding 2 and the second winding 5, and the pressing gap is ≤10% of the thickness of the coil 1. Through this design, the tightness between the windings can be ensured, the vibration and looseness of the windings during operation can be reduced, and the mechanical strength of the winding structure can be increased. In addition, by controlling the pressing gap to ≤10% of the thickness of the coil 1, the distributed capacitance and leakage magnetic effect can be reduced, the electromagnetic coupling efficiency of the first winding 2 and the second winding 5 can be improved, and the electrical performance of the magnetic device can be made more stable. At the same time, the tight coil layout can enhance the thermal conductivity between the windings, help to quickly dissipate heat, and avoid overheating of the coil under high load. The pressing gap is ≤10% of the thickness of the coil 1, which improves the heat dissipation capacity, mechanical strength and device performance of the first winding 2 and the second winding 5.

[0069] In one embodiment, there is a pressing gap between adjacent coils 1 in the first winding 2 and the second winding 5 , and the pressing gap is 3%, 5% or 6% of the thickness of the coil 1 .

[0070] In one embodiment, the area covered by the first sealing body 4 on the first winding 2 is ≥ 10% of the surface area of ​​the first winding 2, and the area covered by the second sealing body 7 on the second winding 5 is ≥ 10% of the surface area of ​​the second winding 5. It can be understood that the first sealing body 4 and the second sealing body 7 are formed by one-time injection molding to provide electrical insulation protection for the first winding 2 and the second winding 5. Then, when the first sealing body 4 partially wraps the first winding 2 and the second sealing body 7 partially wraps the second winding 5, the heat dissipation and insulation balance of the windings can be taken into account, thereby improving the comprehensive performance of the magnetic device.

[0071] In one embodiment, the thickness of the first sealing body 4 and / or the second sealing body 7 is ≥0.3 mm. Based on this thickness limitation, the insulation performance and mechanical strength of the magnetic device are guaranteed, that is, the first sealing body 4 and / or the second sealing body 7 with a thickness ≥0.3 mm can provide more reliable electrical insulation protection, especially in high-voltage or high-frequency application scenarios, which helps to prevent arcing or local discharge, avoid insulation failure, and enhance the mechanical support and protection capabilities of the first winding 2 and the second winding 5, and can effectively prevent damage caused by external force, vibration or thermal expansion and contraction.

[0072] In one embodiment, the thickness of the first encapsulant 4 and / or the second encapsulant 7 is 0.3 mm, which ensures the miniaturization of the magnetic device and reliable electrical insulation and durability.

[0073] It should be noted that the injection molding material of the present application includes at least one of polyethylene terephthalate, acrylonitrile-butadiene-styrene copolymer, polyamide or polycarbonate, and the injection molding materials of the first sealing body 4 and the second sealing body 7 are different. For example, the first sealing body 4 is formed by one-time injection molding of polyethylene terephthalate material, and the second sealing body 7 is formed by one-time injection molding of polyamide material, that is, the insulation effect and heat dissipation effect of the first sealing body 4 and the second sealing body 7 are improved by using different injection molding materials. For example, polyethylene terephthalate (PET) has excellent heat resistance, wear resistance and mechanical strength, and electrical insulation. It has good performance and good dimensional stability, and can maintain performance in a wide temperature range, that is, PET is resistant to high temperatures and has strong aging resistance, as well as good chemical resistance and moisture resistance; acrylonitrile-butadiene-styrene copolymer (ABS) has good impact resistance and toughness; polyamide (PA,) has strong toughness, good electrical insulation performance and heat resistance; polycarbonate (PC) is impact-resistant and high-temperature resistant, has excellent electrical insulation performance and heat resistance, and has good optical transparency and mechanical strength. Using PC as the injection molding material can better wrap the winding and improve the structural strength and insulation strength of the magnetic device.

[0074] Of course, in some embodiments, in addition to the first encapsulant 4 and the second encapsulant 7, the magnetic device may also have a sealing colloid 10 and an extended encapsulant 12, etc., and the injection molding materials of the first encapsulant 4, the second encapsulant 7, the sealing colloid 10 and the extended encapsulant 12 are different.

[0075] In summary, in the method for preparing a plastic-encapsulated magnetic device of the present application, the first winding 2 is obtained by stacking and pressing part of the coil 1, and after the first winding 2 is once injection-molded with an injection molding material to form a first sealing body 4, the first sealing body 4 wraps or partially wraps the area of ​​the first winding 2 except the first ejector positioning area 3, and a part of the coil 1 is stacked and pressed on the first sealing body 4 to form a second winding 5, and after the second winding 5 is once injection-molded with an injection molding material to form a second sealing body 7, the second sealing body 7 wraps or partially wraps the first sealing body 4, and wraps or partially wraps the area of ​​the second winding 5 except the second ejector positioning area 6, and the first winding 2 and the second winding 5 are assembled in the accommodating cavity 9 of the magnetic core body 8, thereby constructing an integrated structure of the plastic-encapsulated magnetic device, improving the insulation withstand voltage capability between the device windings, and ensuring the smaller volume and excellent heat dissipation effect of the device, thereby improving the mechanical stability and insulation capability of the magnetic device.

[0076] It should be noted that the withstand voltage of the plastic-encapsulated magnetic device of the present application is ≥4000VAC, and the partial discharge of the device under high frequency and high voltage is ≤10PC (picocoulomb).

[0077] This embodiment also discloses a plastic-encapsulated magnetic device, which can be made from any of the above embodiments. Figure 2-Figure 8 The plastic-encapsulated magnetic device comprises: a magnetic core body 8, in which a receiving cavity 9 is provided; a plurality of coils 1, wherein some of the coils 1 are stacked and pressed together to form a first winding 2, and the outer surface of the first winding 2 has a plurality of first ejector positioning areas 3; a first sealing body 4, wherein the first sealing body 4 wraps or partially wraps the first winding 2 except for the first ejector positioning area 3, and some of the coils 1 are stacked and pressed together on the first sealing body 4 to form a second winding 5, and the outer surface of the second winding 5 has a plurality of second ejector positioning areas 6; a second sealing body 7, wherein the second sealing body 7 wraps or partially wraps the first sealing body 4, and wraps or partially wraps the second winding 5 except for the second ejector positioning area 6; wherein the first winding 2 and the second winding 5 are connected in the receiving cavity 9.

[0078] That is, the first winding 2 and the second winding 5 of the plastic-encapsulated magnetic device are laminated and wrapped by the first sealing body 4 and the second sealing body 7 by one-time injection molding, thereby constructing an integrated structure of the plastic-encapsulated magnetic device, improving the insulation withstand voltage capability between the device windings, ensuring the smaller size and excellent heat dissipation effect of the device, and improving the mechanical stability and insulation capability of the magnetic device.

[0079] For other working principles and processes of the plastic-encapsulated magnetic device of the present application, please refer to the description of the method for preparing the plastic-encapsulated magnetic device in the aforementioned embodiment of the present invention, which will not be repeated here.

[0080] The above is a detailed introduction to a plastic-encapsulated magnetic device and a preparation method thereof provided by the present application. This article uses specific examples to illustrate the principles and implementation methods of the present application. It should be noted that in the present application, the descriptions of each embodiment have their own emphasis. For parts that are not described or recorded in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0081] The above are only preferred embodiments of the present application, and the patent scope of the present application is not limited thereto. The various technical features of the technical solution of the present application can be arbitrarily combined. In order to make the description concise, not all possible combinations of the various technical features in the above embodiments are described. Any equivalent structure or equivalent process transformation made using the contents of the specification and drawings of this application, or directly or indirectly used in other related technical fields, as long as there is no contradiction in the combination of these technical features, are equally included in the patent protection scope of the present application.

Claims

1. A method for preparing a plastic-encapsulated magnetic device, characterized in that: include: Providing a plurality of coils, wherein the coils are pressed and partially stacked to form a first winding, and the outer surface of the first winding has a plurality of first ejector pin positioning areas; Performing one injection molding on the first winding using an injection molding material to form a first sealing body, wherein the first sealing body wraps or partially wraps an area of ​​the first winding except the first ejector pin positioning area; The partially stacked coils are pressed onto the first sealing body to form a second winding, and the outer surface of the second winding has a plurality of second ejector pin positioning areas; The second winding is once injection molded with the injection molding material to form a second sealing body, wherein the second sealing body wraps or partially wraps the first sealing body and wraps or partially wraps the area of ​​the second winding except the second ejector positioning area; The first winding and the second winding are assembled in the accommodating cavity of the magnetic core body.

2. The method for preparing a plastic-encapsulated magnetic device according to claim 1, characterized in that: Before assembling the first winding and the second winding in the accommodating cavity of the magnetic core body, the method further includes: The second sealing body is injection-molded at least once using the injection molding material to form a sealing body, and the sealing body wraps the second sealing body, the second winding, the first sealing body and the first winding.

3. The method for preparing a plastic-encapsulated magnetic device according to claim 1, characterized in that: Before assembling the first winding and the second winding in the accommodating cavity of the magnetic core body, the method further includes: The partially stacked coils are pressed onto the second sealing body to form an extended winding, and the outer surface of the stacked and pressed extended winding has a plurality of extended ejector pin positioning areas; The extended winding is once injection molded with the injection molding material to form an extended encapsulation body, wherein the extended encapsulation body wraps or partially wraps the second encapsulation body and wraps or partially wraps the area of ​​the extended winding except the extended ejector pin positioning area.

4. The method for preparing a plastic-encapsulated magnetic device according to claim 1, characterized in that: The accommodating cavity of the magnetic core body is provided with a magnetic column, the first winding and the second winding are sleeved and connected on the magnetic column, the first winding has a first lead end, the second winding has a second lead end, and the first lead end and the second lead end extend toward each other outside the magnetic core body.

5. The method for preparing a plastic-encapsulated magnetic device according to claim 1, characterized in that: A plurality of first ejector pin positioning areas are evenly arranged on the outer surface of the first winding, and a plurality of second ejector pin positioning areas are evenly arranged on the outer surface of the second winding, wherein the first ejector pin positioning areas and the second ejector pin positioning areas are not at the same position relative to the vertical projection area of ​​the magnetic core body.

6. The method for preparing a plastic-encapsulated magnetic device according to claim 1, characterized in that: There is a pressing gap between adjacent coils in the first winding and the second winding, and the pressing gap is ≤10% of the thickness of the coil.

7. The method for preparing a plastic-encapsulated magnetic device according to claim 1, characterized in that: The area covered by the first sealing compound on the first winding is ≥10% of the surface area of ​​the first winding, and the area covered by the second sealing compound on the second winding is ≥10% of the surface area of ​​the second winding.

8. The method for preparing a plastic-encapsulated magnetic device according to claim 1, characterized in that: The thickness of the first sealing glue body and / or the second sealing glue body is ≥0.3 mm.

9. The method for preparing a plastic-encapsulated magnetic device according to claim 1, characterized in that: The injection molding material includes at least one of polyethylene terephthalate, acrylonitrile-butadiene-styrene copolymer, polyamide or polycarbonate, and the injection molding materials of the first encapsulant and the second encapsulant are different.

10. A plastic-encapsulated magnetic device, obtained by using the method for preparing a plastic-encapsulated magnetic device according to any one of claims 1 to 9, characterized in that: include: A magnetic core body, wherein a receiving cavity is provided in the magnetic core body; A plurality of coils, some of which are stacked and pressed together to form a first winding, wherein the outer surface of the first winding has a plurality of first ejector pin positioning areas; A first sealing body, wherein the first sealing body wraps or partially wraps an area of ​​the first winding except the first ejector pin positioning area, the partially stacked coils pressed on the first sealing body form a second winding, and the outer surface of the second winding has a plurality of second ejector pin positioning areas; a second sealing body, wherein the second sealing body wraps or partially wraps the first sealing body, and Wrapping or partially wrapping the area of ​​the second winding except the second ejector pin positioning area; Wherein, the first winding and the second winding are connected in the accommodating cavity.

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