A chip transformer

Abstract

The utility model belongs to the technical field of electronic components, concretely relates to a chip transformer, including magnetic core, cladding layer and electrode, wherein, magnetic core includes I -shaped magnetic core and chip magnetic core, the cladding layer is in I -shaped structure and is cladded in the outside of I -shaped magnetic core, and the cladding layer is set up in open -mouthed type near chip magnetic core side, the cladding layer end portion is provided with a plurality of electrodes away from chip magnetic core side, the both ends of I -shaped magnetic core with the chip magnetic core between be provided with air gap structure, the air gap structure includes first air gap spacer close to the end of I -shaped magnetic core, second air gap spacer close to chip magnetic core and the magnetic sheet setting between first air gap spacer and second air gap spacer.

Description

Technical Field

[0001] This utility model belongs to the field of electronic component technology, and specifically relates to a chip transformer. Background Technology

[0002] The statements in this section are merely background information related to this utility model and do not necessarily constitute prior art.

[0003] Currently, the electronics industry has an increasingly strong demand for miniaturized and low-cost magnetic devices, leading to the rise of small-sized, low-process, fully automated chip transformers.

[0004] However, currently commonly used chip transformers involve directly winding wires onto the core body and electroplating electrodes on the core surface, then welding the winding leads through the electroplated electrodes. This process is cumbersome and has high labor costs. Nickel-zinc ferrite cores are generally used, and nickel-zinc ferrite has a very high resistivity, so there is no problem of poor withstand voltage between the winding and the core. However, due to some limitations of the core material itself, existing chip transformers suffer from problems such as low operating efficiency, low excitation inductance, low operating temperature, and failure to meet safety regulations regarding creepage distance. Utility Model Content

[0005] To address the aforementioned issues, this invention proposes a chip transformer. By encasing the magnetic core within a cladding layer, it effectively solves the problems of various withstand voltage and safety creepage distance limitations caused by the low resistance of the magnetic core. Simultaneously, several electrodes are set on the cladding layer, allowing the winding leads to be directly welded to the electrodes during transformer winding. This ensures automated manufacturing while reducing operational steps and lowering labor costs.

[0006] According to some embodiments, the present invention provides a chip transformer, which adopts the following technical solution: A surface-mount transformer includes a winding coil, a magnetic core, a cladding layer, and electrodes. The magnetic core includes an I-shaped magnetic core and a surface-mount magnetic core, with the winding coil adapted to the shape of the I-shaped magnetic core. The cladding layer near the surface-mount magnetic core has an open structure. Several electrodes are disposed at the ends of the cladding layer away from the surface-mount magnetic core. The winding coil is wound around the middle of the cladding layer, and the ends of the winding coil are connected to the corresponding electrodes. An air gap structure is provided between the two ends of the I-shaped magnetic core and the surface-mount magnetic core.

[0007] As a further technical limitation, the air gap structure includes a first air gap pad near the end of the I-shaped magnetic core, a second air gap pad near the plate magnetic core, and a magnetic sheet disposed between the first air gap pad and the second air gap pad.

[0008] As a further technical limitation, the electrode has a wiring portion on a surface away from the cladding layer, and the wiring portion is provided with a groove for accommodating welding at the end of the winding coil.

[0009] As a further technical limitation, the coating layer includes a first coating layer, a second coating layer, and a middle coating layer for connecting the first coating layer and the second coating layer. The open structure is disposed at one end of the first coating layer and the second coating layer near the plate magnetic core, and the winding coil is wound on the middle coating layer.

[0010] Furthermore, the cladding layer extends beyond the end of the I-shaped magnetic core, forming a cladding layer extension.

[0011] Furthermore, a plurality of protrusions are provided on one side of the first and second covering layers away from the opening, and the plurality of protrusions are spaced apart along the width direction of the first or second covering layer; a wire groove is provided between adjacent protrusions, and the electrode is disposed on the protrusion.

[0012] As a further technical limitation, the air gap structure is higher than the height of the coating layer extension.

[0013] Furthermore, the air gap structure is disposed inside the coating layer extension, and the size of the air gap structure matches that of the coating layer extension.

[0014] As a further technical limitation, the coating layer is made of bakelite or plastic and is formed by injection molding.

[0015] As a further technical limitation, an adhesive layer is provided between the coating layer and the I-shaped magnetic core, between the I-shaped magnetic core and the air gap structure, and between the air gap structure and the sheet magnetic core.

[0016] As a further technical limitation, the electrode also has two fixing parts, which are respectively connected to both sides of the wiring part, and the fixing parts extend into the covering layer and are fixedly connected to the plastic sealing covering layer.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention encapsulates the I-shaped magnetic core within a cladding layer, with electrodes positioned on the surface of the cladding layer. An air gap structure is established between the plate magnetic core and the I-shaped magnetic core, effectively solving the problems of various withstand voltage and safety creepage distances caused by low magnetic core resistance. This improves magnetic induction, reduces temperature rise, and is suitable for environments with high operating temperatures. Furthermore, by setting several electrodes on the cladding layer, the ends of the winding coils can be directly welded to the electrodes during transformer winding, eliminating the need to weld the electrodes to the I-shaped magnetic core and then weld the ends of the winding coils. This ensures automated manufacturing while reducing operational steps and lowering labor costs. Attached Figure Description

[0018] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0019] Figure 1 This is another structural schematic diagram of the chip transformer in this utility model embodiment; Figure 2 This is an exploded structural diagram of the chip transformer in an embodiment of this utility model; Figure 3 This is a schematic diagram of the structure of the coating layer in an embodiment of the present utility model; Figure 4 This is a schematic diagram of another structure of the coating layer in an embodiment of the present utility model; Figure 5 This is a schematic diagram of the gasket structure in an embodiment of the present utility model; Figure 6 This is a schematic diagram of another structure of the chip transformer in this embodiment of the present utility model; Figure 7 This is a schematic diagram of another structure of the chip transformer in this embodiment of the present utility model; Figure 8 This is a schematic cross-sectional view of a chip transformer in an embodiment of this utility model; Figure 9 This is a schematic diagram of the structure of an electrode in an embodiment of the present utility model; Among them, 1. Coating layer; 2. I-shaped magnetic core; 3. Plate magnetic core; 4. Winding coil; 5. Air gap structure; 6. First air gap pad; 7. Magnetic sheet; 8. Second air gap pad; 9. Electrode; 10. Wire groove; 11. First coating layer; 12. Middle coating layer; 13. Second coating layer; 14. Boss; 15. Positioning groove; 16. Wiring part; 17. Electrode extension part; 18. Fixing part; 19. Groove. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0022] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0023] In this utility model, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", and "bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of the structural relationship between the various components or elements of this utility model and do not specifically refer to any component or element in this utility model. They should not be construed as limiting this utility model.

[0024] In this utility model, terms such as "fixed connection," "connected," and "joined" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be determined according to the specific circumstances, and should not be construed as a limitation of this utility model.

[0025] Example This utility model embodiment introduces a chip transformer.

[0026] like Figure 1 and Figure 2 The illustrated chip transformer includes a cladding layer 1, an I-core 2, a chip core 3, and winding coils 4. A schematic diagram of the cladding layer 1 is shown below. Figure 4 and Figure 5 As shown, the cladding layer 1 is in the shape of an I-beam and covers the outside of the I-beam magnetic core 2. An opening is provided on one side of the cladding layer 1, and the winding coil 4 is wound on the cladding layer 1. The plate magnetic core 3 is located on one side of the opening.

[0027] It should be noted that the length of the sheet magnetic core 3 is matched with the length of the cladding layer 1, and the width of the sheet magnetic core 3 is matched with the width of the cladding layer 1.

[0028] Specifically, such as Figure 3 and Figure 4 As shown, the I-shaped magnetic core 2 has two ends and a middle section, with the two ends located at both ends of the middle section. The covering layer 1 of the I-shaped structure includes a first covering layer 11, a middle covering layer 12, and a second covering layer 13. The first covering layer 11 and the second covering layer 13 are respectively disposed at both ends of the middle covering layer 12 and are connected to both ends of the middle covering layer 12. At this time, the first covering layer 11 and the second covering layer 13 cover both ends of the I-shaped magnetic core 2, and the middle covering layer 12 is circumferentially covered along the outer surface of the middle section. The side of the first covering layer 11 and the second covering layer 13 near the plate magnetic core 3 is provided with an open structure. In addition, a plurality of electrodes 9 are arranged at intervals on one surface of the first covering layer 11 and the second covering layer 13 away from the open structure. The lead wires of the winding coil 4 are welded to the corresponding electrodes 9. The number and position of the electrodes 9 can be set and adjusted according to the actual position of the lead wires at the ends of the winding coil 4.

[0029] It should be noted that in this embodiment, both the I-core 2 and the plate core 3 are made of soft magnetic materials with high permeability, such as manganese-zinc ferrite, amorphous, nanocrystalline, and permalloy. The cladding layer 1 is made of bakelite or plastic material, and is formed by injection molding to fit the I-core 2. This allows the magnetic material of the I-core 2 to be replaced with a high-permeability magnetic material, solving the problem that high-permeability materials cannot be used to mount electrodes on the surface, effectively reducing temperature rise and losses, and making it suitable for environments with high operating temperatures. In addition, the winding coil 4 uses enameled wire, FIW fully insulated wire, or triple-insulated wire.

[0030] In this embodiment, electrode 9 is made of copper or copper alloy, with a nickel layer electroplated on the surface followed by a tin layer electroplated. The fixed connection between the cladding layer 1 and electrode 9 can be achieved by placing electrode 9 on the cladding layer 1 during re-injection molding, without the need for welding. Figure 7 As shown.

[0031] As one or more implementation methods, such as Figure 3 , Figure 6 and Figure 8 As shown, the first cladding layer 11 and the second cladding layer 13 each have a number of protrusions 14 on the side away from the open structure. The number of protrusions 14 are spaced apart along the width direction of the first cladding layer 11 or the second cladding layer 13. At this time, a wire groove 10 is provided between two adjacent protrusions 14 so that the end of the winding coil 4 can pass through, thereby adjusting the creepage distance. A number of electrodes 9 correspond one-to-one with the protrusions 14 and are respectively located at one end of the corresponding protrusion 14 away from the sheet magnetic core 3.

[0032] Specifically, such as Figure 6 , Figure 8 and Figure 9As shown, electrode 9 has a wiring portion 16, an electrode extension portion 17, and two fixing portions 18. The electrode extension portion 17 is connected to one end of the wiring portion 16 and is arranged along the height direction of the boss 14. The boss 14 is provided with a positioning groove 15 for positioning the electrode extension portion 17 on the side away from the winding coil 4. The electrode extension portion 17 is located in the corresponding positioning groove 15 for quick welding.

[0033] like Figure 8 and Figure 9 As shown, the fixing part 18 is connected to both sides of the wiring part 16. The fixing part 18 is fixedly connected to the boss 14. To enhance stability, the fixing part 18 has recesses on both sides. When the coating layer is injection molded, the electrode 9 is placed on the boss 14. At this time, the fixing part 18 extends into the boss 14, and the recesses are filled with the material of the coating layer 1. The electrode extension part 17 is fixed in the positioning groove 15.

[0034] A groove 19 for accommodating the soldering of the end of the winding coil 4 is provided on the surface of the wiring portion 16 opposite to the covering layer 1. The groove 19 is provided along the length direction of the wiring portion 16 and the width of the groove 19 is equal to the width of the end of the winding coil 4. This arrangement facilitates the quick positioning of the end of the winding coil 4 on the wiring portion 16 and ensures the flatness of the end of the winding coil 4 on the wiring portion 16 when soldering.

[0035] In this embodiment, when there is no air gap requirement in the transformer magnetic circuit, an adhesive layer, made of epoxy glue, is provided between the plate core 3 and the I-core 2 to fix the plate core 3 and the I-core 2. At this time, the opening of the covering layer 1 is flush with the end of the I-core 2 closest to the plate core 3. To achieve precise adjustment of the transformer excitation inductance, when there is an air gap requirement in the transformer magnetic circuit, an air gap structure 5 can be provided between the plate core 3 and the I-core 2. The air gap structure 5 can be a first air gap pad 6. At this time, the two sides of the first air gap pad 6 are fixedly connected to the plate core 3 and the I-core 2 respectively through the adhesive layer.

[0036] As another implementation method, such as Figure 5 As shown, the air gap structure 5 may also include a first air gap pad 6 near the end of the I-shaped magnetic core 2, a second air gap pad 8 near the plate magnetic core 3, and a magnetic sheet 7 disposed between the first air gap pad 6 and the second air gap pad 8.

[0037] It should be noted that the first air gap gasket 6 and the second air gap gasket 8 are made of materials with insulating properties. The shape and size of the first air gap gasket 6 and the second air gap gasket 8 are adaptively adjusted according to the requirements of the I-core 2. They are used when the transformer magnetic circuit requires an air gap.

[0038] It should be noted that the first coating layer 11 and the second coating layer 13 have an extension portion of the coating layer at one end of the open structure, and the extension portion of the coating layer is connected to the open structure; the air gap structure 5 is disposed in the formed extension portion of the coating layer, and epoxy glue for bonding is disposed between the I-shaped magnetic core 2 and the air gap structure 5, and between the air gap structure 5 and the plate magnetic core 3, so as to form a complete plate transformer.

[0039] In this embodiment, the thickness of the first air gap shim 6 and the second air gap shim 8 is half the total air gap size of the magnetic circuit. When the air gap depth of the transformer is greater than 0.5 mm, a segmented air gap method is adopted. This is achieved by setting the first air gap shim 6, the magnetic sheet 7, and the second air gap shim 8 on both sides of the I-shaped magnetic core 2, respectively. The material of the magnetic sheet 7 is the same as that of the I-shaped magnetic core 2. Two air gaps are formed at both ends of the I-shaped magnetic core 2 to reduce leakage flux and improve transformer efficiency.

[0040] Meanwhile, in this embodiment, the height of the covering layer extension is adjusted according to the thickness of the first air gap pad 6 and the second air gap pad 8. The sum of the heights of the first air gap pad 6 and the second air gap pad 8 is set to two-thirds of the height of the covering layer extension, so as to limit the first air gap pad 6 and the second air gap pad 8 and reduce the assembly difficulty.

[0041] As one or more implementation methods, in other embodiments, such as Figure 8 As shown, limiting blocks are provided at the ends of the extensions of the first coating layer 11 and the second coating layer 13 facing the plate magnetic core 3. Specifically, the limiting blocks can be arranged in a straight line, a U-shape, or an L-shape. Specifically, when the limiting blocks are arranged in a straight line, the two limiting blocks are respectively arranged at the two ends of the extensions of the first coating layer 11 and the second coating layer 13 that are far apart. When the limiting blocks are arranged in a U-shape, the plate magnetic core 3 can be accommodated along the space between the two limiting blocks in the extension. The two limiting blocks enable the plate magnetic core 3 to be quickly positioned. At this time, the limiting blocks can be less than or equal to the thickness of the plate magnetic core 3. The length of the plate magnetic core 3 can be equal to the length of the I-shaped magnetic core 2, and the width of the plate magnetic core 3 can be equal to the width of the I-shaped magnetic core 2.

[0042] In this embodiment, a coating layer adapted to the I-core 2 is formed by injection molding, so that the I-core 2 is encased in the coating layer. The chip core 3 uses high permeability magnetic materials such as manganese-zinc ferrite, amorphous, nanocrystalline, and permalloy, and an air gap structure is set between it and the I-core 2. This effectively solves the problems of various withstand voltage and safety creepage distances caused by the low core resistance of chip transformers. It can also improve the excitation inductance and reduce the temperature rise, making it suitable for use in environments with high operating temperatures.

[0043] Meanwhile, several electrodes are set at one end of the cladding layer away from the sheet-type magnetic core 3. The electrodes are inserted during the injection molding of the cladding layer. When the transformer is wound, the end of the winding coil 4 can be directly welded to the electrodes. While ensuring automated manufacturing, this reduces the number of work steps and lowers labor costs.

[0044] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

[0045] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the scope of protection of the present utility model.

Claims

1. A chip transformer, characterized in that, The device includes a winding coil, a magnetic core, a cladding layer, and electrodes. The magnetic core includes an I-shaped magnetic core and a plate magnetic core. The cladding layer covers the outside of the I-shaped magnetic core and is adapted to the shape of the I-shaped magnetic core. The cladding layer near the plate magnetic core has an open structure. Several electrodes are provided at the ends of the cladding layer away from the plate magnetic core. The winding coil is wound around the middle of the cladding layer, and the ends of the winding coil are connected to the corresponding electrodes. An air gap structure is provided between the two ends of the I-shaped magnetic core and the plate magnetic core.

2. A chip transformer as described in claim 1, characterized in that, The electrode has a wiring portion on a surface away from the cladding layer, and the wiring portion has a groove for accommodating welding at the end of the winding coil.

3. A chip transformer as described in claim 1, characterized in that, The cladding layer includes a first cladding layer, a second cladding layer, and a middle cladding layer for connecting the first cladding layer and the second cladding layer. The open structure is disposed at one end of the first cladding layer and the second cladding layer near the plate magnetic core. The winding coil is wound on the middle cladding layer.

4. A chip transformer as described in claim 1, characterized in that, The cladding layer extends beyond the end of the I-shaped magnetic core, forming a cladding layer extension.

5. A chip transformer as described in claim 3, characterized in that, Both the first and second covering layers, which are away from the open structure, have a plurality of protrusions on one side. The plurality of protrusions are spaced apart along the width direction of the first or second covering layer. A wire groove is provided between adjacent protrusions, and the electrode is disposed on the protrusion.

6. A chip transformer as described in claim 4, characterized in that, The air gap structure is higher than the height of the coating layer extension.

7. A chip transformer as described in claim 6, characterized in that, The air gap structure is disposed inside the coating layer extension, and the size of the air gap structure matches that of the coating layer extension.

8. A chip transformer as described in claim 1, characterized in that, The coating layer is made of bakelite or plastic and is formed by injection molding.

9. A chip transformer as described in claim 1, characterized in that, An adhesive layer is provided between the coating layer and the I-shaped magnetic core, between the I-shaped magnetic core and the air gap structure, and between the air gap structure and the sheet magnetic core.

10. A chip transformer as described in claim 2, characterized in that, The electrode also has two fixing parts, which are respectively connected to both sides of the wiring part. The fixing parts extend into the covering layer and are fixedly connected to the plastic sealing covering layer.

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