Coil module for transformer and transformer

Abstract

The present application relates to a coil module for a transformer and a transformer. In the coil module for a transformer, a via passes through the tail end of the first coil and the head end of the second coil, the first hole passes through the head end of the first coil, and the second hole passes through the tail end of the second coil; the first insulating plate has a notch, and the notch has a first end and a second end; the circuit board and the first insulating plate are alternately arranged along the first direction and both have multiples, with the first face and the first end facing the same side; the tail end of the first coil and the head end of the second coil are electrically connected through the first pad in the via; in at least part of the first insulating plate, the first end is aligned with the second hole of the circuit board in contact with it, and the second end is aligned with the first hole of another circuit board in contact with it, and the tail end of the second coil in the circuit board in contact with the first end and the head end of the first coil in the circuit board in contact with the second end are electrically connected through the second pad passing through the notch. The above-mentioned coil module for a transformer can reduce the overall thickness, which is conducive to the miniaturized design of the transformer.

Description

Technical Field

[0001] The present application relates to the technical field of transformers, and in particular to a coil module for a transformer and a transformer. Background Art

[0002] A transformer typically consists of a magnetic core, a high-voltage coil module, and a low-voltage coil module. Conventional winding of enameled wire to form the coil module has poor insulation. Therefore, some transformers currently use a stack of copper-foiled PCBs to form the coil module. In related art, some of these coil modules, where adjacent PCBs are electrically connected via solder pads, result in a relatively thick overall coil module, hindering miniaturization. Summary of the Invention

[0003] Based on this, it is necessary to provide a coil module for a transformer and a transformer, which can reduce the overall thickness of the coil module, thereby facilitating a miniaturized design of the transformer.

[0004] A coil module for a transformer, the coil module for the transformer comprising a coil unit, the coil unit comprising:

[0005] A circuit board, the circuit board having a first surface and a second surface arranged opposite to each other along a first direction, the first surface being provided with a first spiral coil, the second surface being provided with a second spiral coil, the circuit board having a via hole, a first hole, and a second hole extending through the circuit board along the first direction, the via hole passing through the tail end of the first coil and the head end of the second coil, the first hole passing through the head end of the first coil, and the second hole passing through the tail end of the second coil, wherein the first direction is a thickness direction of the circuit board;

[0006] a first insulating plate having a notch extending through the first direction, the notch having a first end and a second end oppositely disposed along the first direction; the circuit boards and the first insulating plates are alternately arranged along the first direction, and a plurality of the circuit boards and the first insulating plates are provided, with each first surface and each first end facing the same side; and

[0007] a first soldering pad and a second soldering pad; the tail end of the first coil and the head end of the second coil are electrically connected through the first soldering pad formed in the via hole; in at least part of the first insulating plate, the first end is aligned with the second hole of the circuit board in contact with it, and the second end is aligned with the first hole of the other circuit board in contact with it, and in the two circuit boards in contact with the first end and the second end respectively, the tail end of the second coil in the circuit board in contact with the first end and the head end of the first coil in the circuit board in contact with the second end are electrically connected through the second soldering pad passing through the gap.

[0008] In one embodiment, each circuit board includes a connecting coil disposed in the first hole, a head end of the first coil is electrically connected to the connecting coil, and the second soldering pad extends into the first hole and is electrically connected to the connecting coil.

[0009] In one embodiment, a socket hole for mating with the magnetic core of the transformer is provided at the center of each circuit board, the first hole and the second hole are symmetrically arranged on both sides of the socket hole along its own radial direction, and the central angles between the first hole, the second hole and the via hole are both 90°;

[0010] The central angle between any two adjacent first holes on the circuit boards is 180°, the central angle between any two adjacent via holes on the circuit boards is 180°, and the central angle between any two adjacent notches on the first insulating boards is 180°.

[0011] In one embodiment, in each of the circuit boards, the first hole and the second hole are located on the outer circle of the circuit board radially away from the sleeve hole, and the via hole is located on the inner circle of the circuit board radially close to the sleeve hole.

[0012] In one embodiment, the first hole extends to the outer edge of the circuit board, and the notch extends to the outer edge of the first insulating plate.

[0013] In one embodiment, the via hole extends to the inner edge of the circuit board.

[0014] In one embodiment, the coil module for the transformer includes a plurality of coil units stacked along the first direction, and each coil unit has one end along the first direction being the circuit board and the other end being the first insulating board.

[0015] In one embodiment, the coil module for the transformer includes a head end lead and a tail end lead. Among the multiple circuit boards, the head end of the first coil of the circuit board located at the head end is electrically connected to the head end lead, and the tail end of the second coil of the circuit board located at the tail end is electrically connected to the tail end lead.

[0016] A transformer, comprising the above-mentioned coil module for a transformer, wherein the coil module for a transformer is a high-voltage winding; the transformer further comprises:

[0017] A low-voltage winding, wherein one of the high-voltage winding and the low-voltage winding is a primary winding and the other is a secondary winding;

[0018] A magnetic core to which both the high voltage winding and the low voltage winding are magnetically coupled.

[0019] In one embodiment, the transformer includes a second insulating plate, the magnetic core includes a central axis group, the second insulating plate, the high-voltage winding and the low-voltage winding are all sleeved on the central axis group; the second insulating plate is provided between the high-voltage winding and the low-voltage winding, as well as at one end of the high-voltage winding facing away from the low-voltage winding, and at one end of the low-voltage winding facing away from the high-voltage winding.

[0020] In the aforementioned coil module and transformer for a transformer, the circuit boards and first insulating plates are arranged alternately along a first direction, and multiple circuit boards are provided for each. Each first surface and each first end face the same side, i.e., the first surface and the second end face each other, and the second surface and the first end face each other. A via passes through the tail end of the first coil and the head end of the second coil. The tail end of the first coil and the head end of the second coil are electrically connected via a first solder pad formed within the via, thereby connecting the first and second coils on each circuit board in series. Because the via can accommodate the first solder pad, there is no need to provide a coil external to the circuit board that wraps from the first surface to the second surface to achieve electrical connection between the first and second coils, which helps reduce the thickness of the entire coil module. In at least some of the first insulating plates, the first end aligns with the second hole of the circuit board in contact with the first end, and the second end aligns with the first hole of the other circuit board in contact with the second end. In the two circuit boards in contact with the first and second ends, respectively, the tail end of the second coil on the circuit board in contact with the first end and the head end of the first coil on the circuit board in contact with the second end are electrically connected via the second solder pad passing through the notch, thereby electrically connecting the two adjacent circuit boards. Since the first end is aligned with the second hole of the circuit board in contact with the first end, and the second end is aligned with the first hole of another circuit board in contact with the second end, when the second soldering pad is formed by soldering in the gap, the second hole and the first hole at both ends of the gap can accommodate the solder overflowing from the gap, so that the solder is not easily accumulated between the first insulating plate and the adjacent circuit board after cooling, thereby making the gap between the first insulating plate and the adjacent circuit board smaller, which is beneficial to reducing the thickness of the entire coil module. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the structure of a transformer in one embodiment of the present application.

[0022] Figure 2 This is a partial structural diagram of a transformer in one embodiment of the present application (magnetic core omitted).

[0023] Figure 3 Schematic diagram of the structure of the magnetic core in one embodiment of the present application.

[0024] Figure 4 This is an exploded diagram of a transformer in one embodiment of the present application.

[0025] Figure 5 Schematic diagram of the structure of the coil unit in one embodiment of the present application.

[0026] Figure 6 This is an exploded view of the coil unit in one embodiment of the present application (only part of the circuit board and part of the first insulating plate are shown).

[0027] Figure 7 This is a front view of a circuit board in one embodiment of the present application.

[0028] Figure 8 This is a schematic diagram of the reverse side of a circuit board in one embodiment of the present application.

[0029] Reference numerals:

[0030] 100. Coil unit; 110. Circuit board; 111. First surface; 112. Second surface; 113. First coil; 114. Second coil; 115. Connecting coil; 116. Via hole; 117. First hole; 118. Second hole; 119. Socket hole; 120. First insulating plate; 121. Notch; 210. Head lead; 220. Tail lead; 300. Low-voltage winding; 400. Magnetic core; 411. First outer frame; 412. First center axis; 421. Second outer frame; 422. Second center axis; 500. Second insulating plate. DETAILED DESCRIPTION

[0031] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0032] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0033] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0034] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0035] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0036] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0037] See Figure 1 、 Figure 2 and Figure 4 The coil module for a transformer provided in one embodiment of the present application includes a coil unit 100, see Figures 5 to 8Coil unit 100 includes multiple circuit boards 110 and multiple first insulating plates 120, with circuit boards 110 and first insulating plates 120 arranged alternately along a first direction, which is the thickness direction of circuit board 110. Circuit board 110 has a first surface 111 and a second surface 112, positioned opposite each other along the first direction. First surface 111 is provided with a spiral-shaped first coil 113, and second surface 112 is provided with a spiral-shaped second coil 114. Circuit board 110 has a via 116, a first hole 117, and a second hole 118 extending through the circuit board 110 along the first direction. Via 116 passes through the tail end of first coil 113 and the leading end of second coil 114. First hole 117 passes through the leading end of first coil 113, and second hole 118 passes through the tail end of second coil 114. First insulating plate 120 has a notch 121 extending through the circuit board 120 along the first direction. Notch 121 has a first end and a second end positioned opposite each other along the first direction. Each first surface 111 and each first end face the same side. Coil unit 100 further includes a first solder pad and a second solder pad (not shown). The tail end of first coil 113 and the head end of second coil 114 are electrically connected via the first solder pad formed in via 116. In at least a portion of first insulating plate 120, the first end aligns with the second hole 118 of the circuit board 110 in contact with it, and the second end aligns with the first hole 117 of the other circuit board 110 in contact with it. Furthermore, in the two circuit boards 110 in contact with the first end and the second end, respectively, the tail end of second coil 114 in the circuit board 110 in contact with the first end and the head end of first coil 113 in the circuit board 110 in contact with the second end are electrically connected via the second solder pad passing through the notch 121.

[0038] In the transformer coil module described above, circuit boards 110 and first insulating plates 120 are arranged alternately along a first direction, with multiple circuit boards 110 and first insulating plates 120 each provided. Each first surface 111 and each first end face the same side, meaning that the first surface 111 and the second end face each other, and the second surface 112 and the first end face each other. A via 116 passes through the tail end of the first coil 113 and the head end of the second coil 114. The tail end of the first coil 113 and the head end of the second coil 114 are electrically connected via a first solder pad formed within the via 116, thereby connecting the first coil 113 and the second coil 114 on each circuit board 110 in series. Because the via 116 can accommodate the first solder pad, there is no need to provide a coil external to the circuit board 110 that winds from the first surface 111 to the second surface 112 to achieve electrical connection between the first coil 113 and the second coil 114, thereby reducing the thickness of the entire coil module. In at least a portion of the first insulating plate 120, the first end is aligned with the second hole 118 of the circuit board 110 in contact with the first end, and the second end is aligned with the first hole 117 of the other circuit board 110 in contact with the second end. In the two circuit boards 110 in contact with the first end and the second end respectively, the tail end of the second coil 114 in the circuit board 110 in contact with the first end and the head end of the first coil 113 in the circuit board 110 in contact with the second end are electrically connected through the second solder pad passing through the notch 121, thereby electrically connecting the two adjacent circuit boards 110. Since the first end is aligned with the second hole 118 of the circuit board 110 in contact with the first end, and the second end is aligned with the first hole 117 of another circuit board 110 in contact with the second end, when the second soldering pad is formed by soldering in the notch 121, the second hole 118 and the first hole 117 at both ends of the notch 121 can accommodate the solder overflowing from the notch 121, so that the solder is not easily accumulated between the first insulating plate 120 and the adjacent circuit board 110 after cooling, thereby making the gap between the first insulating plate 120 and the adjacent circuit board 110 smaller, which is beneficial to reducing the thickness of the entire coil module.

[0039] Specifically, from the perspective of the accompanying drawings, the up-down direction is the first direction. The first coil 113 is helical, with its leading and trailing ends corresponding to one end and the other end of its helical line, respectively. The second coil 114 is helical, with its leading and trailing ends corresponding to one end and the other end of its helical line, respectively. For ease of understanding, the subsequent embodiments will be described using the perspective of the accompanying drawings. However, this orientation represents only relative positions between components, not absolute positions.

[0040] Figure 5 and Figure 6From a visual perspective, the first surface 111 is the top surface of the circuit board 110, and the second surface 112 is the bottom surface of the circuit board 110. The first end of the notch 121 is its top end, and the second end is its bottom end. Each first surface 111 and each first end face the same side, that is, each first surface 111 and each first end face upward, and correspondingly, each second surface 112 and each second end face downward. At least part of the first insulating plate 120 meets the following conditions: the top end of the notch 121 is aligned with the second hole 118 of the circuit board 110 located above and in contact with it, and the bottom end of the notch 121 is aligned with the first hole 117 of the other circuit board 110 located below and in contact with it. In the two circuit boards 110 that are respectively in contact with the top and bottom ends of the notch 121, the tail end of the second coil 114 of the circuit board 110 that is in contact with the top end of the notch 121 and the head end of the first coil 113 of the circuit board 110 that is in contact with the bottom end of the notch 121 are electrically connected through a second solder pad that passes through the notch 121.

[0041] In some embodiments, the first insulating plate 120 is made of a polyethylene plate with a thickness of 0.5 mm and an insulation level of 5,000 V. The first insulating plate 120 is used to insulate the adjacent circuit board 110 to prevent leakage.

[0042] In some embodiments, the first coil 113 and the second coil 114 are formed by printing copper foil on a 0.5 mm thick fiberglass circuit substrate using a standard PCB manufacturing process. The thickness of the copper foil, i.e., the thickness of the first coil 113 and the second coil 114, is preferably 0.025 mm to 0.075 mm.

[0043] See Figures 5 to 8 In some embodiments, each circuit board 110 includes a connecting coil 115 disposed in a first hole 117 , a head end of the first coil 113 is electrically connected to the connecting coil 115 , and a second solder pad extends into the first hole 117 and is electrically connected to the connecting coil 115 .

[0044] As previously mentioned, the first hole 117 passes through the head end of the first coil 113. In the above embodiment, the connecting coil 115 is distributed along the hole wall of the first hole 117 in the first direction, thereby extending to the head end of the first coil 113 and contacting the head end of the first coil 113 to achieve electrical connection. As previously mentioned, the second soldering pad passes through the notch 121 on the first insulating plate 120, and its top end is electrically connected to the tail end of the second coil 114 of the adjacent circuit board 110 above the first insulating plate 120, and its bottom end is electrically connected to the head end of the first coil 113 of the adjacent circuit board 110 below the first insulating plate 120. In the above embodiment, by arranging the connecting coil 115 in the first hole 117, solder can be added during soldering, so that the formed second soldering pad extends into the first hole 117 and contacts the circumference of the connecting coil 115 to achieve electrical connection. Because the first end of the first coil 113 is provided with a first hole 117, the first end of the first coil 113 forms a substantially annular end surface. The connecting coil 115 is located along the wall of the first hole 117, and its area is larger than the approximately annular end of the first coil 113. Therefore, the second soldering pad extends into the first hole 117 and contacts the circumference of the connecting coil 115 to establish an electrical connection. This increases the contact area, reduces the likelihood of winding conduction failure due to poor contact, and improves the reliability of the transformer.

[0045] Of course, in other embodiments, the connecting coil 115 is not provided in the first hole 117 , and the second pad may be directly electrically connected to the head end of the first coil 113 .

[0046] See Figure 1 and Figure 3 ,as well as Figures 6 to 8 In some embodiments, each circuit board 110 is centrally provided with a socket hole 119 for mating with the transformer's magnetic core 400. A first hole 117 and a second hole 118 are symmetrically located radially opposite the socket hole 119. The central angles between the first and second holes 117, 118, and the via holes 116 are both 90°. The central angle between any two adjacent first holes 117 on circuit boards 110 is 180°, the central angle between any two adjacent via holes 116 on circuit boards 110 is 180°, and the central angle between any two adjacent notches 121 on first insulating plates 120 is 180°.

[0047] Specifically, the magnetic core 400 of the transformer includes a central axis group, which includes a first central axis 412 and a second central axis 422 that are coaxial and spaced apart along a first direction. The sleeve hole 119 is used for the central axis group to pass through so that the coil unit 100 is sleeved on the outside of the central axis group. The first hole 117 is located on one side of the sleeve hole 119 along its own radial direction, and the second hole 118 is located on the other side of the sleeve hole 119 along its own radial direction, and the central angle between the two is 180 degrees. The through hole 116 is located in the area between the first hole 117 and the second hole 118, and the central angle between the first hole 117 and the through hole 116, as well as the central angle between the second hole 118 and the through hole 116 are both 90 degrees. When assembling the circuit board 110 and the first insulating plate 120, any two adjacent first insulating plates 120 are placed in a manner rotated 180 degrees around the first direction, and any two adjacent circuit boards 110 are also placed in a manner rotated 180 degrees around the first direction, so that the top end of the notch 121 of the first insulating plate 120 is aligned with the tail end of the second coil 114 of the adjacent circuit board 110 above it, and the bottom end is aligned with the head end of the first coil 113 of the adjacent circuit board 110 below it.

[0048] When configured as described above, all first insulating plates 120 have the same specifications and only need to be positioned at the desired angle. Similarly, all circuit boards 110 have the same specifications and only need to be positioned at the desired angle. This simplifies the structural design and reduces manufacturing costs. Of course, in other embodiments, various specifications of first insulating plates 120 and circuit boards 110 may be provided as needed.

[0049] See Figures 6 to 8 In some embodiments, in each circuit board 110 , the first hole 117 and the second hole 118 are located on the outer circle of the circuit board 110 radially away from the sleeve hole 119 along the sleeve hole 119 , and the via 116 is located on the inner circle of the circuit board 110 radially close to the sleeve hole 119 along the sleeve hole 119 .

[0050] Specifically, since the first coil 113 is spiral-shaped, its head end and tail end must be located on the outside and inside, respectively. Similarly, the head end and tail end of the second coil 114 must also be located on the outside and inside, respectively. In the above embodiment, the first hole 117 and the second hole 118 are located on the outside, and the via 116 is located on the inside. In other words, the head end of the first coil 113 is located on the outside and the tail end is located on the inside, while the tail end of the second coil 114 is located on the outside and the head end is located on the inside. Correspondingly, the notch 121 on the first insulating plate 120 is also located on its outer area.

[0051] Thus, after stacking circuit board 110 and first insulating plate 120, soldering to form the second solder pads allows for more space and facilitates soldering because first hole 117, second hole 118, and notch 121 are all located on the outside. Although via 116 is located on the inside, soldering the tail end of first coil 113 and the head end of second coil 114 on each circuit board 110 can be performed before circuit board 110 and first insulating plate 120 are assembled, making the process more convenient.

[0052] See Figures 6 to 8 In some embodiments, the first hole 117 extends to the outer edge of the circuit board 110 , and the notch 121 extends to the outer edge of the first insulating plate 120 .

[0053] The phrase "first hole 117 extends to the outer edge of circuit board 110" means that the outer side of first hole 117 is connected to the external environment, and notch 121 is similar. This arrangement further facilitates soldering to form the second pad. Preferably, second hole 118 can also extend to the outer edge of circuit board 110.

[0054] See Figures 6 to 8 In some embodiments, the via 116 extends to the inner edge of the circuit board 110 .

[0055] Here, "the via 116 extends to the inner edge of the circuit board 110" means that the inner side of the via 116 is connected to the external environment. This arrangement can further facilitate welding to form the first pad.

[0056] In the above embodiments, the first hole 117, the second hole 118, and the notch 121 are located on the outside, while the via 116 is located on the inside. In other embodiments, the first hole 117, the second hole 118, and the notch 121 may be located on the inside, while the via 116 is located on the outside. In this case, the first coil 113 has its head end located on the inside and its tail end located on the outside, while the second coil 114 has its head end located on the outside and its tail end located on the inside.

[0057] See Figure 2 、 Figure 4 and Figure 5 In some embodiments, the coil module for the transformer includes a plurality of coil units 100 stacked along a first direction, wherein each coil unit 100 has a circuit board 110 at one end along the first direction and a first insulating plate 120 at the other end.

[0058] Specifically, in the embodiment shown in the accompanying drawings, each coil unit 100 includes four circuit boards 110 and four first insulating plates 120. Each circuit board 110 and each first insulating plate 120 are arranged alternately, with the topmost circuit board 110 being the circuit board 110 and the bottommost first insulating plate 120 being the first insulating plate 120. Between any two adjacent coil units 100, the bottommost first insulating plate 120 in the upper coil unit 100 contacts the topmost circuit board 110 in the lower coil unit 100. The connection method between the circuit boards 110 in any two adjacent coil units 100 is the same as the connection method between the circuit boards 110 in a single coil unit 100 in the aforementioned embodiment, and will not be further described here.

[0059] In other embodiments, the number of circuit boards 110 and first insulating plates 120 within each coil unit 100 can be different. The number of circuit boards 110 and first insulating plates 120 can be equal or differ by one, as long as each circuit board 110 and each first insulating plate 120 are arranged alternately. Furthermore, within each coil unit 100, the first insulating plate 120 can be located at the top and the circuit board 110 can be located at the bottom.

[0060] See Figure 1 、 Figure 2 and Figure 4 In some embodiments, the coil module for the transformer includes a head end lead 210 and a tail end lead 220. Among the multiple circuit boards 110, the head end of the first coil 113 of the circuit board 110 located at the head end is electrically connected to the head end lead 210, and the tail end of the second coil 114 of the circuit board 110 located at the tail end is electrically connected to the tail end lead 220.

[0061] Specifically, multiple coil units 100 are stacked and connected in series along a first direction, so that the entire coil module forms a structure similar to each coil unit 100, except that there are more circuit boards 110 and first insulating plates 120. In the entire coil module, the circuit board 110 at the head end is also the topmost circuit board 110, and the circuit board 110 at the tail end is also the bottommost circuit board 110. The head end lead 210 extends into the first hole 117 on the topmost circuit board 110 and is electrically connected to the connecting coil 115, thereby indirectly electrically connecting to the head end of the first coil 113. The tail end lead 220 extends into the notch 121 of the bottommost first insulating plate 120 and is electrically connected to the tail end of the second coil 114 in the bottommost circuit board 110 located above the notch 121.

[0062] In some embodiments, the head lead 210 and the tail lead 220 are made of silicone rubber copper wire with an insulation level of 20,000 volts.

[0063] See Figure 1 、 Figure 2 and Figure 4 A transformer provided in one embodiment of the present application includes the coil module for a transformer according to any of the aforementioned embodiments, wherein the coil module for the transformer is a high-voltage winding. The transformer also includes a low-voltage winding 300 and a magnetic core 400. One of the high-voltage winding and the low-voltage winding 300 is a primary winding, and the other is a secondary winding. Both the high-voltage winding and the low-voltage winding 300 are magnetically coupled to the magnetic core 400.

[0064] Since the coil windings manufactured by printed circuit board printing have good insulation performance and are not easily broken down under high voltage, the high-voltage winding uses the coil module of the above embodiment. The low-voltage winding 300 itself has a lower voltage, so conventional enameled wire winding can be directly used to save costs.

[0065] In some embodiments, the low voltage winding 300 is wound with copper wire having a cross-sectional area of ​​2.5 square millimeters.

[0066] See Figure 1 、 Figure 2 and Figure 4 In some embodiments, the transformer includes a second insulating plate 500, the magnetic core 400 includes a central axis group, the second insulating plate 500, the high-voltage winding and the low-voltage winding 300 are all sleeved on the central axis group; a second insulating plate 500 is provided between the high-voltage winding and the low-voltage winding 300, as well as at one end of the high-voltage winding facing away from the low-voltage winding 300, and at one end of the low-voltage winding 300 facing away from the high-voltage winding.

[0067] Specifically, the magnetic core 400 includes a first outer frame 411, a first central axis 412, a second outer frame 421, and a second central axis 422. The first outer frame 411 and the first central axis 412 are connected as a whole, and the second outer frame 421 and the second central axis 422 are connected as a whole. In the central axis group, the first central axis 412 and the second central axis 422 are coaxially arranged, and there is a gap between them along the first direction. The first outer frame 411 and the second outer frame 421 also have a gap along the first direction. The high-voltage winding, the low-voltage winding 300, and the second insulating plate 500 are all sleeved outside the central axis group. The second insulating plate 500 is used to insulate the high-voltage winding and the low-voltage winding 300, as well as the high-voltage winding and other components at its top, and the low-voltage winding 300 and other components at its bottom.

[0068] In some embodiments, after the transformer is assembled, it is subjected to a vacuum dipping operation for insulating varnish so that the gaps between the panels are filled with insulating varnish to further improve its insulation performance.

[0069] In some embodiments, the second insulating plate 500 is made of a 2 mm thick fiberglass board with an insulation level of 20,000 volts.

[0070] In some embodiments, the magnetic core 400 is a ferrite core. Compared with other types of magnetic materials, the ferrite core has the characteristics of high magnetic permeability, high resistance and low eddy current loss. Therefore, the transformer has the advantages of high resistance and low eddy current loss.

[0071] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned 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.

[0072] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A coil module for a transformer, characterized in that: The coil module for the transformer includes a coil unit, and the coil unit includes: A circuit board, the circuit board having a first surface and a second surface arranged opposite to each other along a first direction, the first surface being provided with a first spiral coil, the second surface being provided with a second spiral coil, the circuit board having a via hole, a first hole, and a second hole extending through the circuit board along the first direction, the via hole passing through the tail end of the first coil and the head end of the second coil, the first hole passing through the head end of the first coil, and the second hole passing through the tail end of the second coil, wherein the first direction is a thickness direction of the circuit board; a first insulating plate having a notch extending through the first direction, the notch having a first end and a second end oppositely disposed along the first direction; the circuit boards and the first insulating plates are alternately arranged along the first direction, and a plurality of the circuit boards and the first insulating plates are provided, with each first surface and each first end facing the same side; and a first soldering pad and a second soldering pad; the tail end of the first coil and the head end of the second coil are electrically connected through the first soldering pad formed in the via hole; in at least part of the first insulating plate, the first end is aligned with the second hole of the circuit board in contact with it, and the second end is aligned with the first hole of the other circuit board in contact with it, and in the two circuit boards in contact with the first end and the second end respectively, the tail end of the second coil in the circuit board in contact with the first end and the head end of the first coil in the circuit board in contact with the second end are electrically connected through the second soldering pad passing through the gap.

2. The coil module for a transformer according to claim 1, characterized in that: Each circuit board includes a connecting coil disposed in the first hole, a head end of the first coil is electrically connected to the connecting coil, and the second soldering pad extends into the first hole and is electrically connected to the connecting coil.

3. The coil module for a transformer according to claim 2, characterized in that: A socket hole for mating with the magnetic core of the transformer is provided at the center of each circuit board, the first hole and the second hole are symmetrically arranged on both sides of the socket hole along its own radial direction, and the central angles between the first hole, the second hole and the via hole are both 90°; The central angle between any two adjacent first holes on the circuit boards is 180°, the central angle between any two adjacent via holes on the circuit boards is 180°, and the central angle between any two adjacent notches on the first insulating boards is 180°.

4. The coil module for a transformer according to claim 3, characterized in that: In each of the circuit boards, the first hole and the second hole are located on the outer circle of the circuit board radially away from the sleeve hole, and the via hole is located on the inner circle of the circuit board radially close to the sleeve hole.

5. The coil module for a transformer according to claim 4, characterized in that: The first hole extends to the outer edge of the circuit board, and the notch extends to the outer edge of the first insulating plate.

6. The coil module for a transformer according to claim 4, characterized in that: The via hole extends to the inner edge of the circuit board.

7. The coil module for a transformer according to any one of claims 1 to 6, characterized in that: The coil module for the transformer includes a plurality of coil units stacked along the first direction. In each coil unit, one end along the first direction is the circuit board, and the other end is the first insulating board.

8. The coil module for a transformer according to claim 7, characterized in that: The coil module for the transformer includes a head end lead and a tail end lead. Among the multiple circuit boards, the head end of the first coil of the circuit board located at the head end is electrically connected to the head end lead, and the tail end of the second coil of the circuit board located at the tail end is electrically connected to the tail end lead.

9. A transformer, characterized in that: The transformer comprises the coil module for the transformer according to any one of claims 1 to 8, wherein the coil module for the transformer is a high-voltage winding; the transformer further comprises: A low-voltage winding, wherein one of the high-voltage winding and the low-voltage winding is a primary winding and the other is a secondary winding; A magnetic core to which both the high voltage winding and the low voltage winding are magnetically coupled.

10. The transformer according to claim 9, characterized in that The transformer includes a second insulating plate, the magnetic core includes a central axis group, the second insulating plate, the high-voltage winding and the low-voltage winding are all sleeved on the central axis group; the second insulating plate is provided between the high-voltage winding and the low-voltage winding, as well as at one end of the high-voltage winding facing away from the low-voltage winding, and at one end of the low-voltage winding facing away from the high-voltage winding.

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