Transformer, mutual inductor or inductor and coil thereof

Abstract

The utility model discloses a transformer, a mutual inductor or an inductor and a coil of the transformer, the mutual inductor or the inductor. The transformer, the mutual inductor or the inductor comprises an integral ferrite magnetic core and at least one coil, the coil is wound on a magnetic conducting frame of the ferrite magnetic core and comprises a plurality of laminated components, and the laminated components are connected end to end and are stacked into a spiral shape in the axial direction of the coil; each laminated component comprises a C-shaped conductive circuit and two bonding pads connected with the two ends of the C-shaped conductive circuit respectively, and the bonding pad at the tail of the upper layer of laminated component is connected with the bonding pad at the head of the lower layer of laminated component to form a continuous conductive path. The coil is suitable for the integral magnetic core, the integral magnetic core does not have the risk of loose connection of combined parts, and a transformer, a mutual inductor or an inductor is good in magnetic performance, high in efficiency, easy to manufacture and low in cost.

Description

Technical Field

[0001] This utility model relates to an electromagnetic device consisting of a magnetic core and a winding, and more particularly to a transformer, current transformer or inductor and its coil. Background Technology

[0002] Transformers, instrument transformers, and inductors are electromagnetic devices consisting of a magnetic core and windings, and are widely used in power systems and electronic circuits.

[0003] Utility model patent CN201220038597.5 discloses a planar transformer for a switching power supply, comprising a magnetic core, a low-voltage coil and a high-voltage coil coupled through the magnetic core. The low-voltage coil is a planar coil, which includes a plurality of stacked coils, each stacked by at least two C-shaped metal rings. The stacked coil structure of this utility model can only employ a composite magnetic core. Compared to a monolithic, enclosed magnetic core, the composite magnetic core carries the risk of loose connections between components; air gaps between components can easily cause electromagnetic leakage, affecting magnetic properties and overall efficiency; and the composite magnetic core requires more assembly steps and higher precision requirements, increasing manufacturing complexity and cost. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a coil that can be used in the integral magnetic core of transformers, instrument transformers or inductors.

[0005] Another technical problem to be solved by this invention is to provide a transformer, current transformer or inductor with an integral magnetic core to overcome the shortcomings of the aforementioned background technology.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is a coil of a transformer, current transformer or inductor, comprising a plurality of stacked components, the plurality of stacked components being connected end to end and stacked in a spiral shape along the axial direction of the coil; the stacked components include C-shaped conductive lines and two pads respectively connected to the two ends of the C-shaped conductive lines, the pads at the tail of the upper stacked component being connected to the pads at the head of the lower stacked component to form a continuous conductive path.

[0007] The coil described above, the stacked component includes a semi-ring, at least one of the two connected semi-rings is spiral, the upper semi-ring is rotated by a set angle relative to the lower semi-ring, each end of the semi-ring includes the aforementioned pad, the pad at the tail of the upper semi-ring is connected to the pad at the head of the lower semi-ring to form a continuous conductive path.

[0008] The coils described above, wherein the semi-ring is an L-shaped ring, a semi-circular ring, or a Π-shaped ring.

[0009] The coil described above has a semi-circular portion that is a printed circuit board, comprising an insulating film layer, a conductive line layer, and a solder mask layer as a substrate. The conductive line layer is attached to the insulating film layer and includes the conductive lines and the two pads. The solder mask layer covers the insulating film layer and the conductive line layer and includes two pad windows. The pads of the conductive line layer are arranged in the corresponding pad windows of the solder mask layer.

[0010] The printed circuit board for the coil and its semi-ring described above is a single-sided circuit board. The two pads of the semi-ring on one side of the coil's main axis face downwards, and the two pads of the semi-ring on the other side of the coil's main axis face upwards; a solder layer is included between the two interconnected pads.

[0011] The coil described above includes two coil pins, which are double-sided printed circuit boards. Each end of the coil pin includes a pad, with one pad facing upwards and the other facing downwards. The pad facing downwards on the first coil pin is soldered to the pad facing upwards on the head of the uppermost half-ring, and the pad facing upwards on the second coil pin is soldered to the pad facing downwards on the tail of the lowermost half-ring.

[0012] The coils described above, as well as the double-sided printed circuit board and the single-sided circuit board, are flexible circuit boards.

[0013] The coil described above includes a flexible circuit board, and a plurality of the stacked components are arranged separately in the circuit layer of the flexible circuit board along the vertical direction; the flexible circuit board is rolled into a cylindrical shape around the vertical main axis of the coil, and the conductive lines of the stacked components in the flexible circuit board are bent into a C-shape through the flexible circuit board; the two ends of the flexible circuit board overlap at the connection part of the cylindrical shape, and each end of the flexible circuit board includes a pad window corresponding to the stacked component, and the pads at both ends of the stacked component are respectively arranged in the corresponding pad windows at the two ends of the flexible circuit board; at the overlapping part of the two ends of the cylindrical flexible circuit board, the pad window at the inner end faces outward, the pad window at the outer end faces inward, the corresponding pad windows are opposite each other, and the corresponding pads include a solder layer.

[0014] The coil described above, the flexible circuit board includes two pin lines, the pad ends of the pin lines include pin pads; the upper and lower parts of the outer surface of the flexible circuit board each include a pin pad window, the pin pads of the two pin lines are respectively arranged in the corresponding pin pad windows, and the non-pad ends of the two pin lines are electrically connected to the pads at the head of the uppermost stacked component and the pads at the tail of the lowermost stacked component, respectively.

[0015] A transformer, instrument transformer, or inductor includes a ferrite core and at least one of the aforementioned coils, the coils being wound around a magnetically conductive frame of the ferrite core, wherein the ferrite core is an integral core and the magnetically conductive frame is a closed, integrated frame.

[0016] The coil of this invention is suitable for use in integral magnetic cores. Integral magnetic cores eliminate the risk of loose connections between assembled components. Transformers, current transformers, or inductors have good magnetic properties, high efficiency, are simple to manufacture, and have low cost. Attached Figure Description

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0018] Figure 1 This is a front view of the transformer in Embodiment 1 of this utility model.

[0019] Figure 2 This is a top view of the transformer in Embodiment 1 of this utility model.

[0020] Figure 3 This is a left view of the transformer in Embodiment 1 of this utility model.

[0021] Figure 4 This is a right view of the transformer in Embodiment 1 of this utility model.

[0022] Figure 5 This is the front view of the L-shaped semi-ring of Embodiment 1 of this utility model.

[0023] Figure 6 This is a left view of the L-shaped semi-ring of Embodiment 1 of this utility model.

[0024] Figure 7 This is a top view of the L-shaped semi-ring of Embodiment 1 of this utility model.

[0025] Figure 8 yes Figure 7 AA section view in the image.

[0026] Figure 9 This is an exploded view of the coil in Embodiment 1 of this utility model.

[0027] Figure 10 This is a perspective view of the L-shaped semi-ring of Embodiment 1 of this utility model.

[0028] Figure 11 This is a perspective view of the coil pins in Embodiment 1 of this utility model.

[0029] Figure 12 This is a top view of the Π-shaped semi-ring of Embodiment 2 of this utility model.

[0030] Figure 13 This is a top view of the semi-circular semi-ring of Embodiment 3 of this utility model.

[0031] Figure 14 This is a perspective view of the transformer in Embodiment 4 of this utility model.

[0032] Figure 15This is a front view of the flexible circuit board of Embodiment 4 of this utility model.

[0033] Figure 16 This is a rear view of the flexible circuit board of Embodiment 4 of this utility model.

[0034] Figure 17 This is an internal structural diagram of the flexible circuit board in Embodiment 4 of this utility model.

[0035] Figure 18 This is a schematic diagram of the flexible circuit board being rolled up according to Embodiment 4 of this utility model.

[0036] Figure 19 yes Figure 15 BB section view in the middle.

[0037] Figure 20 This is a cross-sectional view of the cylindrical flexible circuit board of Embodiment 4 of this utility model.

[0038] Figure 21 This is a perspective view of the transformer in Embodiment 5 of this utility model.

[0039] Figure 22 This is a front view of the flexible circuit board of Embodiment 5 of this utility model.

[0040] Figure 23 This is a rear view of the flexible circuit board of Embodiment 5 of this utility model.

[0041] Figure 24 This is an internal structural diagram of the flexible circuit board in Embodiment 5 of this utility model.

[0042] Figure 25 This is a schematic diagram of the flexible circuit board being rolled up according to Embodiment 5 of this utility model. Detailed Implementation

[0043] The structure of the transformer in Embodiment 1 of this utility model (the structure of the current transformer or inductor is the same, only the number of coils may be different) is as follows: Figures 1 to 11 As shown, it includes a ferrite core 100 and two coils 200. The coils 200 are wound on the magnetic guide frame of the ferrite core 100. The ferrite core 100 is an integral core 100, and the magnetic guide frame is a closed integral frame.

[0044] The coil 200 includes multiple stacked components and two coil leads. The multiple stacked components are connected end to end and stacked in a spiral shape along the axial direction of the coil 200. Each stacked component includes a C-shaped conductive line and two pads connected to both ends of the C-shaped conductive line. The pads at the tail of the upper stacked component are connected to the pads at the head of the lower stacked component to form a continuous conductive path.

[0045] The laminated component of Embodiment 1 of this utility model adopts an L-shaped semi-ring 10, and the two connected L-shaped semi-rings 10 are both spiral.

[0046] The semi-ring 10 adopts a single-sided flexible printed circuit board structure, including an insulating film layer 11, a conductive line layer 12, and a solder mask layer 13 as a substrate. The conductive line layer 12 is attached to the insulating film layer 11 and includes conductive lines and two pads 121. The solder mask layer 13 covers the insulating film layer 11 and the conductive line layer 12, and includes two pad windows 131. The pads 121 of the conductive line layer 12 are arranged in the corresponding pad windows 131 of the solder mask layer 13.

[0047] During connection, the upper half-ring 10 rotates 180° relative to the lower half-ring 10. Each end of the half-ring 10 includes a pad 121. The pad 121 at the tail of the upper half-ring 10 is soldered to the pad 121 at the head of the lower half-ring 10 to form a continuous conductive path.

[0048] In Embodiment 1 of this utility model, all the two pads 121 of the semi-rings 10 on one side of the main axis PP of the coil 200 face downwards, while all the two pads 121 of the semi-rings 10 on the other side of the main axis PP of the coil 200 face upwards. The two pads 121 that are welded together are welded together by a welding layer 14.

[0049] The coil pins 20 are made of flexible double-sided printed circuit boards. Each end of the coil pin 20 includes a pad 21, with one pad facing upwards and the other facing downwards. The downward-facing pad 21 of the first coil pin 20A is soldered to the upward-facing pad 121 of the uppermost half-ring 10 through a solder layer 15. The upward-facing pad 21 of the second coil pin 20B is soldered to the downward-facing pad 121 of the lowermost half-ring 10 through a solder layer 16.

[0050] The components of coil 200 are assembled on the magnetically conductive frame of ferrite core 100. Before assembly, the surfaces of the pads 121 of half-ring 10 and the pads 21 of coil pin 20 are tin-plated to form a tin plating layer. During assembly, the assembled half-ring 10 and coil pin 20 are clamped together with a jig and reflow soldered together with ferrite core 100. The tin plating layer on the pads is melted by high temperature and then cooled and solidified, so that the pads of adjacent half-rings are connected together by the tin solder layer, and the pads of coil pins are also connected to the pads of half-rings by the tin solder layer, forming a continuous conductive path of coil 200.

[0051] The structure of the Π-shaped semi-ring in Embodiment 2 of this utility model is as follows: Figure 12 As shown, the semi-circular and semi-ring structure of Embodiment 3 of this utility model is as follows: Figure 13 As shown.

[0052] The structure of the transformer in Embodiment 4 of this utility model (the structure of the current transformer or inductor is the same, only the number of coils may be different) is as follows: Figures 14 to 20 As shown, it also includes a ferrite core 100 and two coils 200. The coils 200 are wound on the magnetic guide frame of the ferrite core 100. The ferrite core 100 is an integral core 100, and the magnetic guide frame is a closed integral frame.

[0053] In Embodiment 4 of this utility model, the coil 200 is formed by curling and soldering a flexible circuit board 200A. Multiple stacked components 31 are arranged vertically in the circuit layer 30 of the flexible circuit board 200A. The stacked components 31 are inclined, and the vertical height of the pads at the tail of the upper stacked component is the same as the height of the pads at the head of the lower stacked component. This ensures that when the flexible circuit board 200A is curled, the pads at the tail of the upper stacked component and the pads at the head of the lower stacked component are connected together, forming a continuous conductive path. The flexible circuit board 200A is curled into a cylindrical shape around the vertical main axis of the coil 200, and the conductive lines 311 of the stacked components 31 in the flexible circuit board 200A are bent into a C-shape by the curling of the flexible circuit board 200A. The two ends of the flexible circuit board 200A overlap at the cylindrical soldering area. Each end of the flexible circuit board 200A includes a pad window 40 corresponding to the stacked member 31. The pads 312 at both ends of the stacked member 31 are respectively arranged in the corresponding pad windows 40 at the two ends of the flexible circuit board 200A. At the overlapping area at both ends of the cylindrical flexible circuit board 200A, the pad window 40A at the inner end faces outward, and the pad window 40B at the outer end faces inward. The corresponding pad windows 40 are opposite each other, and the corresponding pads 312 are soldered together by the soldering layer 313.

[0054] The flexible circuit board 200A has a pin 50 at its upper and lower ends. The circuit layer 30 of the flexible circuit board 200A includes two pin lines 32, which are respectively arranged in the upper and lower pins 50. Each pin line 32 has a pin pad 321 at its pad end. The upper and lower parts of the outer surface of the flexible circuit board 200A each include a pad window 40C corresponding to the pin pad 321. The pin pads 321 of the two pin lines 32 are respectively arranged in the corresponding pad windows 40C. The non-pad end of the lower pin line 32 is directly connected to the pad 312B at the tail of the lowest layer stacked component 31. The lower end of the upper pin line 32 has a transition pad 322, which is arranged in the pad window 40D. After the flexible circuit board 200A is rolled up, the transition pad 322 is soldered to the pad 312A at the head of the uppermost layer stacked component 31.

[0055] The flexible circuit board 200A of the coil 200 also needs to be assembled on the magnetically conductive frame of the ferrite core 100. Before assembly, the surfaces of the pads 312 at both ends of the stacked components 31 of the flexible circuit board 200A are tin-plated to form tin-plated layers. During assembly, the flexible circuit board 200A is rolled up, and the tin-plated layer on the tail pad of the upper stacked component overlaps with the tin-plated layer on the head pad of the lower stacked component. The fixture clamps the rolled flexible circuit board 200A onto the magnetically conductive frame of the ferrite core 100, and reflows it together with the ferrite core 100. The tin-plated layer on the pads is melted by high temperature and then cooled and solidified to form a continuous conductive path for the coil 200.

[0056] The structure of the transformer in Embodiment 5 of this utility model is as follows: Figures 21 to 25 As shown, the only difference between this transformer and the one in Embodiment 4 is the arrangement of the upper pin 50A and the pin line 32. The upper pin 50A is directly arranged above the pad 312A at the head of the uppermost stacked component 31, and the lower end of the upper pin line 32 is directly connected to the pad 312A at the head of the uppermost stacked component 31.

[0057] The transformer, instrument transformer, or inductor of the above embodiments of this utility model have the following advantages:

[0058] 1) Coils formed by welding are suitable for integral magnetic cores. Integral magnetic cores do not have the risk of loose connections of assembled parts. Transformers, current transformers or inductors have good magnetic properties, high efficiency, simple manufacturing and low cost.

[0059] 2) The integral ferrite core has low hysteresis loss and eddy current loss at high frequencies, and can maintain high efficiency and reduce energy loss when handling high frequency currents; the ferrite core can be formed by pressing, sintering and other processes, which is low cost and provides good cost performance.

Claims

1. A coil of a transformer, a mutual inductor or an inductor comprising a plurality of stacked members, characterized in that, The plurality of stacked members are connected end to end and stacked in a spiral shape along the axial direction of the coil; the stacked member comprises a C-shaped conductive circuit and two pads respectively connected to the two ends of the C-shaped conductive circuit, the pad at the tail of the upper stacked member is connected to the pad at the head of the lower stacked member, forming a continuous conductive path.

2. The coil of claim 1, wherein The stacked member comprises a half ring, at least one of the two connected half rings is in a spiral shape, the half ring of the upper layer is turned by a set angle relative to the half ring of the lower layer, the two ends of the half ring each comprise the pad, the pad at the tail of the half ring of the upper layer is connected to the pad at the head of the half ring of the lower layer, forming a continuous conductive path.

3. The coil of claim 2, wherein, The half ring is an L-shaped ring, a semi-circular ring or a Π-shaped ring.

4. The coil of claim 2, wherein, The half ring is a printed circuit board, comprising an insulating film layer as a substrate, a conductive circuit layer and a solder mask layer, the conductive circuit layer is attached to the insulating film layer, the conductive circuit layer comprises the conductive circuit and the two pads; the solder mask layer covers the insulating film layer and the conductive circuit layer, the solder mask layer comprises two pad windows, the pads of the conductive circuit layer are arranged in the corresponding pad windows of the solder mask layer.

5. The coil of claim 4, wherein, The printed circuit board of the half ring is a single-sided circuit board, the two pads of the half ring on one side of the main axis of the coil face downward, and the two pads of the half ring on the other side of the main axis of the coil face upward; a welding layer is arranged between the two pads connected to each other.

6. The coil of claim 5, wherein, The coil comprises two coil pins, the coil pin is a double-sided printed circuit board, the two ends of the coil pin each comprise a pad, one of the two pads of the coil pin faces upward, and the other faces downward; the downward-facing pad of the first coil pin is welded to the upward-facing pad at the head of the uppermost half ring, and the upward-facing pad of the second coil pin is welded to the downward-facing pad at the tail of the lowermost half ring.

7. The coil of claim 6, wherein, The double-sided printed circuit board and the single-sided circuit board are flexible circuit boards.

8. The coil of claim 1, wherein, The coil comprises a flexible circuit board, a plurality of the stacked members are arranged in the circuit layer of the flexible circuit board in the vertical direction; the flexible circuit board is curled into a cylindrical shape around the vertical main axis of the coil, the conductive circuit of the stacked member in the flexible circuit board is curled into a C shape through the flexible circuit board; the two ends of the flexible circuit board in the transverse direction overlap at the connection part of the cylindrical shape, the two ends of the flexible circuit board in the transverse direction each comprise a pad window corresponding to the stacked member, the pads at the two ends of the stacked member are arranged in the corresponding pad windows of the two ends of the flexible circuit board in the transverse direction respectively; at the overlapping part of the two ends of the cylindrical flexible circuit board, the pad window of the inner end part faces outward, and the pad window of the outer end part faces inward, the corresponding pad windows are opposite to each other, and a welding layer is arranged between the corresponding pads.

9. The coil of claim 8, wherein, The flexible circuit board comprises two pin circuits, the pad end of the pin circuit comprises a pin pad; the upper part and the lower part of the outer surface of the flexible circuit board each comprise a pin pad window, the pin pads of the two pin circuits are arranged in the corresponding pin pad windows respectively, and the non-pad end of the two pin circuits are electrically connected to the pad at the head of the uppermost stacked member and the pad at the tail of the lowermost stacked member respectively.

10. A transformer, a mutual inductor or an inductor comprising a ferrite core and at least one coil, the coil being wound on a magnetically conductive frame of the ferrite core, characterized in that, The ferrite core is a monolithic core, the magnetic conductive frame is a closed integrated frame; the coil is the coil according to any one of claims 1 to 9.

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