Planar winding and method for manufacturing a planar winding, and planar transformer

Abstract

The application discloses a planar winding and a manufacturing method thereof, and a planar transformer. The planar winding comprises one or more planar winding track units. Any planar winding track unit is obtained by patterning an insulating substrate covered with conductive material on at least one surface, which comprises a winding track area and a non-winding track area. The winding track area comprises a first conductive material surrounding or partially surrounding the magnetic core hole after the patterning, as the winding track of the planar winding track unit; the non-winding track area comprises a blank area after the patterning. The non-winding track area of at least one planar winding track unit further comprises a second conductive material after the patterning, which is separated from the winding track area by the blank area and forms an electronic component or a part of an electronic component.

Description

Technical Field

[0001] This application relates to an electronic device, and more particularly to a planar winding and a method for manufacturing the same, as well as a planar transformer having the planar winding. Background Technology

[0002] Planar transformers, characterized by their small size and thinness, are widely used in modern electronic devices. Generally, a planar transformer consists of a magnetic core and planar windings. Planar windings are formed by stacking layers of planar winding trace units. One method of fabricating these trace units involves laying a conductive material on an insulating substrate, then retaining the desired conductive material to form a conductive pattern, while removing the unwanted conductive material. This removal of conductive material results in waste. Furthermore, the removal of conductive material creates a step difference between the retained and removed areas, leading to an uneven surface on the final planar winding. Summary of the Invention

[0003] The technical problem to be solved by the embodiments of this application is the waste caused by the removal of conductive material during the preparation of the planar winding wiring unit, and the step difference between the area where the conductive material is retained and the area where it is removed, which affects the flatness of the overall product.

[0004] To address the aforementioned technical problems, this application provides a circuit structure incorporating a planar transformer. This circuit structure fully utilizes the conductive material that would otherwise be removed during the fabrication process of the planar transformer windings, reducing waste and thus lowering product costs. Simultaneously, most of the conductive material is retained, minimizing the step difference between the retained and removed areas and maintaining the overall flatness of the product.

[0005] To achieve the above objectives, this application provides a planar winding, comprising one or more planar winding trace units. Each planar winding trace unit is obtained by patterning an insulating substrate including at least one magnetic core hole and having at least one side covered with a conductive material. The surface includes a winding trace area and a non-winding trace area. The winding trace area includes a first conductive material, obtained after the patterning process, surrounding or partially surrounding the magnetic core hole, serving as the winding trace of the planar winding trace unit. The non-winding trace area includes a blank area obtained after the patterning process. Furthermore, the non-winding trace area of ​​at least one of the one or more planar winding trace units further includes a second conductive material, obtained after the patterning process. The second conductive material is separated from the winding trace area by the blank area and forms an electronic component or part of an electronic component.

[0006] In one feasible implementation, the conductive material includes at least one of conductive metal foil, conductive paste, and conductive film.

[0007] In one feasible implementation, the conductive material includes copper foil or copper alloy foil.

[0008] In one feasible implementation, the electronic component includes a resistor, a capacitor, or a combination thereof.

[0009] In one feasible implementation, the electronic component is connected to an external device via pads or wires.

[0010] In one feasible implementation, the one or more planar winding trace units are stacked to form the planar winding, and the core holes of each planar winding trace unit are aligned with each other after stacking.

[0011] In one feasible implementation, the winding trace area and / or the blank area includes at least one conductive hole, and the winding traces of each planar winding trace unit are connected sequentially through the conductive hole based on the stacking order.

[0012] Accordingly, this application also provides a method for fabricating a planar winding, wherein the planar winding wiring unit integrates electronic components. The method includes: obtaining a raw material board, the raw material board including at least one through-hole and at least one side covered with a conductive material; determining a first reserved area and a region to be processed on the surface, the first reserved area surrounding or partially surrounding the through-hole; removing a portion of the conductive material located in the region to be processed by patterning to obtain a blank area and a second reserved area, wherein the blank area is adjacent to the first reserved area, and the second reserved area is separated from the first reserved area by the blank area; and fabricating the electronic component or a portion of the electronic component based on the conductive material located in the second reserved area.

[0013] In one feasible implementation, the electronic component includes a resistor, a capacitor, or a combination thereof, and is connected to an external device via pads or wires.

[0014] This application also provides a planar transformer, which includes planar windings as described above.

[0015] Implementing this application has the following beneficial effects: it can fully utilize the conductive material that should have been removed during the fabrication of the planar winding, reducing waste of conductive material and thus lowering product costs. Simultaneously, most of the conductive material is retained, thereby reducing the step difference between the retained and removed areas and maintaining the overall flatness of the product. Attached Figure Description

[0016] Figure 1 These are exemplary structural schematic diagrams of planar windings according to some embodiments of this application;

[0017] Figure 2 This is a schematic diagram of another exemplary structure of a planar winding according to some embodiments of this application; and

[0018] Figure 3 This is an exemplary flowchart of the preparation of a planar winding trace unit according to some embodiments of this application.

[0019] The reference numerals in the figure are as follows: 100 - First planar winding routing unit, 110 - First magnetic core hole, 120 - First winding routing area, 130 - First non-winding routing area, 140 - First electronic component, 150 - First conductive hole, 200 - Second planar winding routing unit, 210 - Second magnetic core hole, 220 - Second winding routing area, 230 - Second non-winding routing area, 240 - Second electronic component, 250 - Second conductive hole. Detailed Implementation

[0020] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0021] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0022] Unless otherwise defined, 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 application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0023] The term “and / or” as used herein includes any and all combinations of one or more of the related listed items.

[0024] This application discloses a planar winding trace unit. The planar winding trace unit can be obtained by patterning an insulating substrate, including at least one core hole, and having at least one side covered with a conductive material. The core hole allows a magnetic core to pass through. When the planar winding trace units are assembled into a planar winding, the core holes of each planar winding trace unit will be aligned to ensure smooth passage of the magnetic core during the assembly of a planar transformer. The insulating substrate can be made of any material with electrical insulating properties, such as graphite, polymeric plastics, etc. The conductive material covering the insulating substrate can include conductive metal foil, including but not limited to copper foil, aluminum foil, titanium foil, zirconium foil, tantalum foil, nickel foil, molybdenum foil, or any combination thereof. Optionally or preferably, the conductive material can include copper foil or copper alloy foil. Optionally, the conductive material can include conductive paste, including but not limited to conductive silver paste, conductive gold paste, conductive copper paste, conductive nickel paste, pure copper paste, carbon paste, conductive silver-palladium paste, conductive silver-copper paste, etc., or any combination thereof. Optionally, the conductive material may include conductive thin films, including but not limited to ITO thin films, GaN thin films, graphene thin films, carbon nanotube thin films, silver nanofilms, metal meshes, and any combination thereof. Through patterning processes, including but not limited to mechanical methods such as grinding and polishing, and non-mechanical methods such as electrochemical etching, plasma etching, photolithography, etching, printing, and coating, unwanted conductive materials can be removed according to preset requirements. For example, assuming an etching method is used, the machine can be controlled to remove the conductive material according to a predetermined etching program.

[0025] After the patterning process, the planar winding trace unit can have winding trace areas and non-winding trace areas formed on its surface. The winding trace areas may include a first conductive material surrounding or partially surrounding the core hole, serving as the winding trace of the planar winding trace unit. The first conductive material may be a conductive material retained on the insulating substrate after the patterning process. These conductive materials are interconnected. In other words, the first conductive material retained after the patterning process constitutes the winding trace areas. The winding trace areas form the conductive lines of the planar winding trace unit. The non-winding trace areas may include blank areas obtained after the patterning process. These non-winding trace areas were originally covered with conductive material, which can be completely or partially removed during the patterning process. The removed portion of the conductive material can form the blank areas. The remaining conductive material can perform other functions. For example, it can serve as a positioning point when multiple planar winding trace units are stacked, or as a soldering point to support other electronic components.

[0026] In one or more planar winding trace units constituting a planar winding, at least one planar winding trace unit's non-winding trace region further includes a second conductive material obtained after the patterning process. The second conductive material may be a portion of the conductive material retained when the conductive material in the non-winding trace region is removed. The second conductive material is separated from the winding trace region by a blank region. Through the blank region, the second conductive material is electrically isolated from the first conductive material constituting the winding trace region, and they do not affect each other.

[0027] The second conductive material can form an electronic component or part of an electronic component. The electronic component may include a resistor or a capacitor. It is known that conductive materials all have a certain resistivity. According to the law of resistance, a conductive material with a stable cross-sectional area and a suitable length has a resistance value. By removing the conductive material in the non-winding trace area while retaining the conductive material with a specific orientation and shape, these conductive materials can be used as a resistor. On the other hand, two conductors close to each other with a non-conductive insulating medium sandwiched in between can form a capacitor. Planar winding trace units are stacked when forming planar windings, and the planar winding trace unit can have winding trace areas or non-winding trace areas on one or both sides. By using the second conductive material in the non-winding trace area as one conductor of the capacitor, and the insulating substrate as the insulating medium between the conductors, a capacitor can be obtained.

[0028] Electronic components made of a second conductive material can be connected to external devices via pads or wires. For example, electronic components can be soldered to pads on external devices, such as circuit boards, using interfaces such as pins, to connect to the external devices. Alternatively, electronic components can be directly connected to nodes on external devices, such as circuit boards, via jumper wires.

[0029] One or more planar winding trace units can be stacked to form a planar winding. In some embodiments, the one or more planar winding trace units can be stacked together with an adhesive layer to form a planar winding. As an example, assuming a planar winding is formed by stacking three planar winding trace units, the top surface of the bottommost planar winding trace unit can be covered with an adhesive layer and then bonded to the bottom surface of the middle planar winding trace unit. Similarly, the top surface of the middle planar winding trace unit can also be covered with an adhesive layer and bonded to the bottom surface of the top planar winding trace unit, thereby obtaining the planar winding. In some embodiments, the adhesive layer can be formed of an insulating adhesive. Exemplary insulating adhesives may include polyester, epoxy resin, polyurethane, polybutadiene acid, silicone, polyesterimide, polyimide, etc.

[0030] After stacking, the core holes of each planar winding unit can be aligned with each other. This alignment can be achieved by the core holes of each planar winding unit forming a channel that allows the core to pass through unobstructed. During the assembly of the core and planar windings into a planar transformer, the core can be embedded into the planar windings through this channel. In some embodiments, the winding routing area and / or blank area of ​​each planar winding unit may include at least one conductive hole. The winding routings of each planar winding unit can be connected sequentially through the conductive holes based on the stacking order. For example, if a planar winding is formed by stacking three planar winding units, the winding routings of the topmost planar winding unit can be connected to the winding routings of the second-layer planar winding unit through conductive holes, and then to the winding routings of the third-layer planar winding unit through conductive holes. When assembled with the core into a planar transformer, the winding routings of these sequentially connected planar winding units constitute the transformer coil of the planar transformer.

[0031] The following description, with reference to the accompanying drawings, illustrates some preferred embodiments of the present application. It should be noted that the following description is for illustrative purposes only and is not intended to limit the scope of protection of this application.

[0032] Figure 1 This is an exemplary schematic diagram of a planar winding trace unit according to some embodiments of this application. The first planar winding trace unit 100 is a basic unit constituting a planar winding. A planar winding may include one or more planar winding trace units. For example... Figure 1 As shown, the first planar winding trace unit 100 includes a core hole 110, a winding trace area 120, a non-winding trace area 130, a reserved area 140, and a conductive hole 150.

[0033] The core hole 110 can be used for the passage of the magnetic core. After one or more planar winding trace units form a planar winding, the core holes 110 of each planar winding trace unit can be aligned with each other to form a channel through which the magnetic core can pass smoothly. The shape of the core hole 110 can be regular or irregular. For example, the shape of the core hole 110 can match the shape of the magnetic core. If the magnetic core is a cylindrical core, the core hole 110 can be a circular through hole.

[0034] The first winding trace region 120 and the first non-winding trace region 130 can be regions formed during the fabrication of the first planar winding trace unit 100. The first planar winding trace unit 100 can be obtained by patterning an insulating substrate including at least one first core hole 110 and having at least one side covered with conductive material. During the patterning process, the conductive material included in the first winding trace region 120 can be retained, forming a winding trace surrounding or partially surrounding the first core hole 110. The conductive material included in the first non-winding trace region 130 is completely or partially removed, forming a blank region (not shown in the figure) adjacent to the winding trace region. When the conductive material included in the first non-winding trace region 130 is partially removed, the remaining conductive material can form a first retained region 140.

[0035] Continue to refer to Figure 1 The first reserved region 140 can be used to form the resistor of an electronic component. It should be noted that... Figure 1 Only one electronic element formed by the first reserved area 140 is shown, but the number of electronic elements formed by the first reserved area 140 may be two, three or more. Figure 1 The examples provided are for illustrative purposes only and do not limit the scope of protection sought in this application.

[0036] The first conductive hole 150 can serve as a connection point, connecting in series the winding traces of one or more planar winding trace units to form a planar winding. These planar winding trace units can form a planar winding after being stacked. The winding traces of each planar winding trace unit can be connected in series through the first conductive hole 150.

[0037] refer to Figure 2 , Figure 2 This is another exemplary schematic diagram of a planar winding trace unit according to some embodiments of this application. For example... Figure 2 As shown, the second planar winding trace unit 200 includes a second core hole 210, a second winding trace region 220, and a second non-winding trace region 230, which can be the same as or similar to the first core hole 110, the first winding trace region 120, and the first non-winding trace region 130, respectively. The second reserved region 240 can form part of an electronic component capacitor, for example, one of the two conductors constituting the capacitor. If the planar winding trace unit is obtained by patterning a double-sided coated insulating substrate, the second reserved regions 240 on each side combined with the insulating substrate can form a complete capacitor. If the planar winding trace unit is obtained by patterning a single-sided coated insulating substrate, the second reserved region 240 on the surface of the coated substrate combined with the second reserved region 240 on the surface of the coated substrate of the next layer of planar winding trace unit, combined with the insulating substrate, can form a complete capacitor.

[0038] The second reserved area 240 can also be used to form a combination circuit of the same and / or different electronic components. For example, the second reserved area 240 can be used to form a filter circuit composed of resistors and capacitors.

[0039] The second conductive hole 250 can serve as a connection point, connecting in series the winding traces of one or more planar winding trace units to form a planar winding. These planar winding trace units can form a planar winding after being stacked. The winding traces of each planar winding trace unit can be connected in series through the second conductive hole 250.

[0040] The planar winding trace unit disclosed in this application makes full use of the conductive material that would otherwise need to be removed during the manufacturing process, reducing waste and lowering manufacturing costs. At the same time, the retained conductive material reduces the step difference between the winding traces and the blank areas formed by the removal of conductive material, maintaining the flatness of the product.

[0041] Some embodiments of this application also disclose a planar transformer. The planar transformer includes a magnetic core and a planar winding. The planar winding may be a planar winding formed by one or more planar winding wiring units as described above.

[0042] Some embodiments of this application also disclose a method for fabricating a planar winding trace unit. Electronic components can be integrated onto this planar winding trace unit. A description of the method can be found in [reference needed]. Figure 3 . Figure 3 This refers to a method for manufacturing a planar transformer according to some embodiments of this application. For example... Figure 3 As shown, process 300 may include the following operations.

[0043] Step S310: Obtain the raw material plate.

[0044] In some embodiments, the raw material plate can be made of any material with electrical insulating properties, such as graphite, polymeric plastics, etc. The raw material plate has at least one through-hole. The shape of the through-hole can be arbitrary; for example, the through-hole can be a regular shape, such as a circle or a regular polygon. The through-hole can also be irregular in shape, without specific limitation. In some embodiments, the conductive material can include conductive metal foil, including but not limited to copper foil, aluminum foil, titanium foil, zirconium foil, tantalum foil, nickel foil, molybdenum foil, or any combination thereof. Optionally or preferably, the conductive material can include copper foil or copper alloy foil. Optionally, the conductive material can include conductive paste, including but not limited to conductive silver paste, conductive gold paste, conductive copper paste, conductive nickel paste, pure copper paste, carbon paste, conductive silver-palladium paste, conductive silver-copper paste, etc., or any combination thereof. Optionally, the conductive material can include conductive thin film, including but not limited to ITO thin film, GaN thin film, graphene thin film, carbon nanotube thin film, nano-silver thin film, metal mesh, etc., or any combination thereof.

[0045] Step S320: Determine the first reserved area and the area to be processed on the surface, wherein the first reserved area surrounds or partially surrounds the through hole.

[0046] In some embodiments, the first retained region may include conductive material to be retained in subsequent steps of process 300. The region to be processed may include conductive material that is completely or partially removed in subsequent steps of process 300. The first retained region may surround or partially surround the via. The conductive material it includes may serve as the winding trace of a planar winding trace unit. In some embodiments, the determination of the first retained region and the region to be processed may be based on the size, shape, direction, electrical properties, etc., of the winding trace of the ultimately desired planar winding trace unit.

[0047] Step S330: Remove a portion of the conductive material located in the area to be processed by patterning to obtain a blank area and a second reserved area.

[0048] In some embodiments, the patterning process includes, but is not limited to, mechanical methods such as grinding and polishing, and non-mechanical methods such as electrochemical etching, plasma etching, photolithography, etching, printing, and coating. In some embodiments, the patterning process may include etching. An etching apparatus is controlled according to a predetermined etching program to remove a portion of the conductive material in the area to be processed on the surface, to obtain a blank area and a first retained area. The conductive material previously covering the blank area is completely removed. The conductive material in the second retained area is retained. This retained conductive material can perform other functions. For example, it can be used as a positioning point during the assembly of a planar winding trace unit into a planar winding, or as a soldering point to support electronic components. In some embodiments, the second retained area and the first retained area are separated by the blank area. Through the blank area, the conductive material in the second retained area is electrically isolated from the conductive material in the first retained area, and they do not affect each other.

[0049] Step S340: Prepare the electronic component or a portion thereof based on the second reserved region.

[0050] In some embodiments, the electronic component may include a resistor or a capacitor. It is known that conductive materials all possess a certain resistivity. According to the law of resistance, a conductive material with a stable cross-sectional area and a suitable length has a resistance value. By retaining conductive material with a specific orientation and shape when removing the conductive material from the area to be treated, this conductive material can be used as a resistor. For example, two conductors close to each other with a non-conductive insulating medium sandwiched between them can constitute a capacitor. The conductive material in the second retained region can then serve as one conductor of the capacitor. The raw material plate can serve as the insulating medium between the two conductors. When the fabricated planar winding trace unit is assembled (e.g., based on a stacking method) with other planar winding trace units to form a planar winding, the conductive material in the second retained region of another planar winding trace unit adjacent to the first planar winding trace unit can serve as another conductor of the capacitor.

[0051] In some embodiments, electronic components can be connected to external devices via pads or wires. For example, electronic components can be soldered to pads on external devices, such as circuit boards, using interfaces such as pins, to connect to the external devices. Alternatively, electronic components can be directly connected to nodes on external devices, such as circuit boards, via jumper wires.

[0052] In some embodiments, through holes on the raw material plate serve as core holes for the planar winding trace unit, and a first reserved area formed of conductive material serves as the winding trace for the planar winding trace unit. Multiple planar winding trace units can be assembled into a planar winding in a stacked manner. For example, they can be stacked together using adhesive layers to form the planar winding. For instance, assuming a planar winding is formed by stacking three planar winding trace units, the top surface of the bottommost planar winding trace unit can be covered with an adhesive layer and then bonded to the bottom surface of the middle planar winding trace unit. Similarly, the top surface of the middle planar winding trace unit can also be covered with an adhesive layer and bonded to the bottom surface of the top planar winding trace unit, thereby obtaining the planar winding. The adhesive layer can be formed of an insulating adhesive. Exemplary insulating adhesives may include polyester, epoxy resin, polyurethane, polybutadiene acid, silicone, polyesterimide, polyimide, etc.

[0053] To connect the winding traces of the stacked planar winding trace units in series, at least one conductive via can be provided in the first reserved area and / or the blank area of ​​the planar winding trace unit. The winding traces of each planar winding trace unit can be connected sequentially through the conductive via based on the stacking order. For example, a planar winding is formed by stacking three planar winding trace units. The winding trace of the topmost planar winding trace unit can be connected to the winding trace of the second planar winding trace unit through the conductive via, and then connected to the winding trace of the third planar winding trace unit through the conductive via.

[0054] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0055] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A planar winding, characterized in that, Includes one or more planar winding trace units; Any planar winding trace unit is obtained by patterning an insulating substrate that includes at least one magnetic core hole and at least one side is covered with conductive material, wherein the at least one side includes a winding trace area and a non-winding trace area. The winding trace area includes a first conductive material partially surrounding the magnetic core hole after the patterning process, which serves as the winding trace of the planar winding trace unit; the non-winding trace area includes a blank area after the patterning process. Wherein, at least one planar winding trace unit's non-winding trace area further includes a second conductive material obtained after the patterning process, the second conductive material being separated from the winding trace area by the blank area and forming an electronic component; The patterning process includes mechanical processing, and the second conductive material forms a capacitor through two conductors close to each other with a non-conductive insulating medium sandwiched in between.

2. The planar winding according to claim 1, characterized in that, The conductive material includes at least one of conductive metal foil, conductive paste, and conductive film.

3. The planar winding according to claim 2, characterized in that, The conductive material includes copper foil or copper alloy foil.

4. The planar winding according to claim 1, characterized in that, The electronic components are connected to external devices via pads or wires.

5. The planar winding according to claim 1, characterized in that, The planar winding routing units are stacked to form the planar winding, and the core holes of each planar winding routing unit are aligned with each other after stacking.

6. The planar winding according to claim 5, characterized in that, The winding trace area and / or the blank area include at least one conductive hole, and the winding traces of each planar winding trace unit are connected sequentially through the conductive hole based on the stacking order.

7. A planar transformer, characterized in that, The planar transformer includes the planar winding as described in any one of claims 1-6.

8. A method for fabricating a planar winding trace unit, used to fabricate one or more planar winding trace units comprising a planar winding as described in any one of claims 1-6, wherein the planar winding trace unit integrates electronic components, characterized in that, The method includes: Obtain a raw material plate, the raw material plate including at least one through hole and at least one side covered with a conductive material; A first reserved area and a region to be processed are determined on at least one side, wherein the first reserved area partially surrounds the through hole; A portion of the conductive material in the area to be processed is removed by patterning to obtain a blank area and a second retained area, wherein the blank area is adjacent to the first retained area, and the second retained area is separated from the first retained area by the blank area; The electronic component is fabricated based on a conductive material located in the second reserved region.

9. The method according to claim 8, characterized in that, The electronic components are connected to external devices via pads or wires.

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