CN108270078B - A high-efficiency wireless charging receiving antenna - Google Patents

Abstract

The invention discloses a wireless charging receiving antenna structure, comprising: a substrate; m coils disposed on the substrate; an isolation region disposed between two adjacent coils; a coil groove disposed on an outermost N turns of the coil, wherein N < M; a first electrode electrically connected to a first end of the coil; and a second electrode electrically connected to the second end of the coil.

Description

A high-efficiency wireless charging receiving antenna

technical field

The present invention relates to the technical field of wireless charging, in particular to a high-efficiency wireless charging receiving antenna.

Background technique

Wireless charging technology refers to a technology that realizes non-contact power transmission through air medium not through wires but through electromagnetic induction, electromagnetic resonance, etc. Compared with traditional charging methods, wireless charging technology does not require wiring and charging terminals, and has higher convenience. With the development of power electronic devices, power conversion and control technology, wireless charging technology has gradually made breakthroughs in conversion rate and low radiation. At present, wireless charging has been realized in some household appliances such as electric toothbrushes, electric shavers, and cordless phones. Practical, and now its application scope has expanded to the field of smartphones. In the future, wireless charging technology will continue to expand to more fields such as medical treatment, electric power, aerospace, energy conservation and environmental protection.

Among various wireless charging technology solutions, the most mature and common is the electromagnetic induction method, which must be the mainstream mode of wireless charging in recent years. From the perspective of electromagnetic induction wireless charging technology, improving high efficiency is the main breakthrough direction in the future, and the wireless charging receiving antenna is a key factor affecting charging efficiency.

At present, the existing wireless charging receiving antenna scheme is usually the FPC antenna as shown in Figure 1. The copper wire width of the antenna coil is uniform, usually 11 double-layer windings, the wire width is about 1 mm, and the winding spacing is about 0.1 mm, the copper layer thickness of the coil is about 45 microns. In the case of AC wireless charging, due to the skin effect, eddy current and other factors, this FPCB winding scheme makes it difficult to improve the transmission energy efficiency, the quality factor is low, and the temperature rise is high.

In order to overcome the above problems, the patent CN 107452483 A proposes a method for winding a wire group, as shown in Figure 2, by subdividing the wires to overcome the skin effect and improve the quality factor, thereby improving the charging efficiency. However, this method is difficult to achieve miniaturization and miniaturization due to factors such as the size and specification of the wire group. For example, it is difficult to meet the requirements of the wireless charging solution for smartphones.

Therefore, there is a need in the art for a novel high-efficiency wireless charging receiving antenna, which at least partially solves the problems in the prior art, such as difficulty in improving transmission energy efficiency, high temperature rise, and low quality factor.

SUMMARY OF THE INVENTION

In view of the problems existing in the prior art, according to an embodiment of the present invention, a wireless charging receiving antenna structure is provided, including:

substrate;

M coils arranged on the substrate;

an isolation area arranged between two adjacent coils;

coil grooves provided on the outermost N turns of the coil, where N<M;

electrically connected to a first electrode on the first end of the coil; and

is electrically connected to a second electrode on the second end of the coil.

In an embodiment of the present invention, the winding width of the M coils gradually increases from the inside to the outside.

In one embodiment of the present invention, the coil is a double-layer wound coil.

In an embodiment of the present invention, the M=11; the N=4.

In an embodiment of the present invention, the coil grooves are discontinuous arc grooves, and the arc grooves are concentric with the coil in which the coil grooves are located.

In an embodiment of the present invention, the discontinuous arc-shaped grooves of the coils disposed on the outermost N turns of the coils are distributed in a radially equal arc.

In one embodiment of the present invention, the isolation region is an unfilled gap or a gap filled with insulating material.

In one embodiment of the present invention, the width of the coil gradually increases from 0.9 mm to 1.3 mm from the inside to the outside, the thickness of the coil is 40 to 70 microns; the width of the isolation region is 80 to 120 microns ; The width of the coil groove is 80 microns to 120 microns.

In an embodiment of the present invention, the coil groove provided on the outermost N turns of the coil further comprises:

K coil grooves arranged on the outermost L circle of the coil, wherein L<N, K≥2;

The J coil grooves are arranged on the secondary outer I turn of the coil, wherein L+I≤N, 1≤J<K.

In one embodiment of the present invention, the substrate is a flexible circuit substrate.

A high-efficiency wireless charging FPC receiving antenna structure provided by the present invention is formed by arranging multi-turn coils with gradually increasing line widths from the inside to the outside on the substrate, and setting discontinuous coil grooves on several coils near the outside. Compared with the traditional solution, the resistance of the antenna structure is reduced, the skin effect of the coil and the influence of the eddy current from the broadband of the line are reduced, the transmission energy efficiency is improved, and the temperature rise during the charging process is improved.

Description of drawings

In order to further clarify the above and other advantages and features of the various embodiments of the present invention, a more specific description of the various embodiments of the present invention will be presented with reference to the accompanying drawings. It is understood that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. In the drawings, the same or corresponding parts will be denoted by the same or similar numerals for clarity.

FIG. 1 shows a schematic structural diagram of a wireless charging FPC receiving antenna in the prior art.

FIG. 2 shows a schematic structural diagram of another wireless charging receiving antenna in the prior art.

FIG. 3 shows a front view of a high-efficiency wireless charging FPC receiving antenna structure formed according to an embodiment of the present invention.

FIG. 4 shows a partial front view of a high-efficiency wireless charging FPC receiving antenna structure formed according to an embodiment of the present invention.

FIG. 5 shows a partial cross-sectional schematic diagram of a high-efficiency wireless charging FPC receiving antenna structure formed according to an embodiment of the present invention.

FIG. 6 shows a comparison diagram of transmission energy efficiency between a high-efficiency wireless charging FPC receiving antenna formed according to an embodiment of the present invention and a conventional solution.

FIG. 7 shows a comparison diagram of temperature rise during charging of a high-efficiency wireless charging FPC receiving antenna formed according to an embodiment of the present invention and a conventional solution.

FIG. 8 shows a partial front view of a high-efficiency wireless charging FPC receiving antenna structure formed according to yet another embodiment of the present invention.

Detailed ways

In the following description, the invention is described with reference to various embodiments. However, one skilled in the art will recognize that the various embodiments may be practiced without one or more of the specific details or with other alternative and/or additional methods, materials or components. In other instances, well-known structures, materials, or operations are not shown or described in detail so as not to obscure aspects of the various embodiments of the invention. Similarly, for purposes of explanation, specific quantities, materials and configurations are set forth in order to provide a thorough understanding of the embodiments of the invention. However, the present invention may be practiced without the specific details. Furthermore, it is to be understood that the various embodiments shown in the drawings are illustrative representations and are not necessarily drawn to scale.

In this specification, reference to "one embodiment" or "the embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. The appearances of the phrase "in one embodiment" in various places in this specification are not necessarily all referring to the same embodiment.

A high-efficiency wireless charging FPC receiving antenna structure provided by the present invention is formed by arranging multi-turn coils with gradually increasing line widths from the inside to the outside on the substrate, and setting discontinuous coil grooves on several coils near the outside. Compared with the traditional solution, the resistance of the antenna structure is reduced, the skin effect of the coil and the influence of the eddy current from the broadband of the line are reduced, the transmission energy efficiency is improved, and the temperature rise during the charging process is improved.

The following describes a high-efficiency wireless charging FPC receiving antenna structure formed according to an embodiment of the present invention with reference to FIG. 3 and FIG. 4 . Fig. 3 shows a front view of a high-efficiency wireless charging FPC receiving antenna structure 300 formed according to an embodiment of the present invention; Fig. 4 shows a high-efficiency wireless charging FPC receiving antenna formed according to an embodiment of the present invention A partial front view of structure 300 .

As shown in FIG. 3 , the high-efficiency wireless charging FPC receiving antenna structure 300 includes a first electrode 301 , a second electrode 302 , a coil 303 , an isolation region 304 , and a coil slot 305 . The first electrode 301 and the second electrode 302 are used to form an electrical connection with the energy receiver, so as to conduct the induced current generated by the coil to the energy receiver; the coil 303 converts the change of the induced magnetic field into an induced current based on the principle of electromagnetic induction; The isolation area 304 is used to electrically insulate the adjacent coils 303; the coil grooves 305 are arranged on the coils 303, and are used to divide the coil wires at the position of the coil grooves 305 into two parallel wires, and the coil grooves 305 are formed into a certain arc. The intermittent grooves are only provided on the outer turns of the coil.

A further structure of the high-efficiency wireless charging FPC receiving antenna structure 300 will be described in detail below with reference to FIG. 4 . As shown in FIG. 4 , the width of the coil 303 gradually becomes wider from the inside to the outside. In a specific implementation of the present invention, the coil 303 is a double-layer coil with 11 turns in total, and the width from the inside to the outside gradually increases from 0.9 mm. As large as 1.3 mm, the thickness of the coil is about 60 microns, and the width of the coil gradually increases from the inside to the outside, which can significantly reduce the internal resistance of the overall coil, because the closer to the outside, the longer the circumference of the coil. When the thickness and length cannot be changed, Good results can be achieved with width adjustment.

Continuing as shown in FIG. 4 , isolation regions 304 are evenly distributed between every two turns of the coils 303 . In a specific embodiment of the present invention, the width of the isolation regions 304 is about 0.1 mm (100 microns), and the isolation regions 304 may be In order to isolate the unfilled gap, it may also be a structure filled with insulating material after isolation.

As shown in FIG. 4 , coil grooves 305 are arranged on the coils near the outermost coils. The coil grooves 305 divide the coil wires in the area where the grooves are located into two parallel wires, thereby reducing the skin of the whole coil when working. effect and the influence of eddy current, in a specific embodiment of the present invention, the coil groove 305 is arranged on the outermost 4 coils, the coil groove 305 and the coil are in a concentric arc shape, and the width of the coil groove 305 is about It is 0.1 mm (100 microns), and the coil grooves 305 on a circle of coils are distributed in N segments of circular arcs that are evenly interrupted, N≥2, and the adjacent coil grooves 305 on the coil are complete coil conductors. The design has lower coil resistance compared to the continuous grooves provided on the coil; in another specific embodiment of the present invention, the coil grooves 305 provided on the outer coils 303 are distributed in a radial and equal arc. , as shown in the radial direction α ₁ and α ₂ shown in FIG. 4 .

Those skilled in the art should know the specific numbers about the number of layers, turns, width, and thickness of the coil 303 in the above-mentioned embodiment, about the width of the isolation region 304, and about the number of turns and points of the coil trench 305 on the coil 303. The number of segments, lengths, widths, and whether they are distributed with equal radians in the radial direction are not limitations of the present invention, but only serve as functions of exemplary embodiments. As long as the width of the coil gradually increases from the inside to the outside, the technical solution that discontinuous coil grooves are distributed on the outer part of the coil all belong to the protection scope of the present invention.

A high-efficiency wireless charging FPC receiving antenna structure 500 formed according to another embodiment of the present invention will be further described below with reference to FIG. 5 . FIG. 5 shows a partial cross-sectional schematic diagram of a high-efficiency wireless charging FPC receiving antenna structure formed according to an embodiment of the present invention. The cross-sectional area of Fig. 5(A) is from the position indicated by the dashed line AA' shown in Fig. 3 .

As shown in FIG. 5(A), the high-efficiency wireless charging FPC receiving antenna structure 500 further includes a substrate 501, the substrate 501 is a flexible circuit substrate, and the M coils 502 are arranged on the substrate 501. In a specific embodiment, M=11, that is, there are coils 502-1, 502-2... 502-11 disposed on the substrate 501, and the width of the coil 502-1 to the coil 502-11 gradually widens from 0.9 mm to 1.3 mm mm; an isolation region 503 is provided between the coils, and in a specific embodiment of the present invention, the width of the isolation region 503 is about 0.1 mm; near the outside of the substrate 501, that is, the left side in FIG. 5(A), There are 4 coils with coil grooves 504. As shown in FIG. 5(B), the coil grooves 504 are similar to the above-mentioned coil grooves 305, and are also discontinuous arc grooves, and the width of the grooves is also about 0.1 mm.

In order to illustrate the technical effect of the present invention more clearly, a comparative test is carried out between the traditional antenna scheme and the antenna scheme of the present invention. The specific scheme of the comparative test is as follows:

In the traditional scheme, as shown in Figure 1, the coil is double-layered with 11 turns, the coil width is 1 mm, the coil thickness is 45 microns, and the winding spacing is 0.1 mm.

In the scheme of the present invention, as shown in Figure 3, the coil is double-layered with 11 turns, the width of the coil is gradually widened from 0.9 mm to 1.3 mm, the thickness of the coil is 60 microns, and the winding spacing is 0.1 mm. Spaced slots.

After testing, the basic electrical parameters are shown in Table 1 below:

Table 1 Comparison table of antenna electrical performance between traditional scheme and invention scheme

From the comparison of the above table, it can be seen that the Rs and Rdc of the solution of the present invention are significantly lower than those of the traditional solution, and the Q value is also higher than that of the traditional solution.

The transmission energy efficiency and temperature increase of the traditional solution and the inventive solution are tested and compared below with reference to FIG. 6 and FIG. 7 . Fig. 6 shows a comparison diagram of transmission energy efficiency between a high-efficiency wireless charging FPC receiving antenna formed according to an embodiment of the present invention and a traditional solution; Fig. 7 shows a high-efficiency wireless charging antenna formed according to an embodiment of the present invention. The comparison chart of the temperature rise between the charging FPC receiving antenna and the traditional solution.

As shown in FIG. 6 , except for the range where the output current is lower (for example, the range where the output current is less than about 0.3A), the antenna scheme of the present patent has a 1%-2% improvement in transmission energy efficiency compared to the traditional scheme, The increase in transmission energy efficiency corresponds to an improvement in losses such as temperature rise and additional radiation.

As shown in FIG. 7 , the antenna solution of the present patent has a lower temperature rise during the charging process than the traditional solution, and the average temperature can be lower by 2-3°C. The reduction in temperature rise improves product experience, increases product life and reduces energy consumption.

An implementation based on another embodiment of the present invention will be described below with reference to FIG. 8 . FIG. 8 shows a partial front view of a high-efficiency wireless charging FPC receiving antenna structure 800 formed according to another embodiment of the present invention, as shown in FIG. 8, the high-efficiency wireless charging FPC receiving antenna structure is similar to the wireless charging FPC receiving antenna structure 300 shown in FIG. As at 801-j, starting from the coil 801-j, a single discontinuous coil groove 803 is provided thereon; as the coil width continues to increase to threshold B, as at 801-k, from the coil 801- Starting with k, two trenches 804 are provided thereon. Those skilled in the art should understand that this embodiment is only an example, and according to similar designs, 3, 4, etc. similar coil grooves can be provided based on the increase in the width of the coil to reduce the skin effect and line bandwidth of the coil. eddy current.

The high-efficiency wireless charging FPC receiving antenna structure provided according to the present invention is formed by arranging multi-turn coils with gradually increasing line widths from the inside to the outside on the substrate, and setting discontinuous coil grooves on the several turns of the coils close to the outside. Compared with the traditional solution, the resistance of the antenna structure is reduced, the skin effect of the coil and the influence of the eddy current from the broadband of the line are reduced, the transmission energy efficiency is improved, and the temperature rise during the charging process is improved.

While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be apparent to those skilled in the relevant art that various combinations, modifications and changes can be made therein without departing from the spirit and scope of the present invention. Therefore, the breadth and scope of the invention disclosed herein should not be limited by the above-disclosed exemplary embodiments, but should be defined only in accordance with the appended claims and their equivalents.

Claims (9)

1. A wireless charging receiving antenna structure, comprising: substrate; M coils arranged on the substrate; an isolation area arranged between two adjacent coils; Coil grooves arranged on the outermost N turns of the coil, where N<M, the coil grooves are used to divide the coil wires at the position of the coil grooves into parallel wires, and the coil grooves are Intermittent grooves in a certain arc; electrically connected to a first electrode on the first end of the coil; and electrically connected to a second electrode on the second end of the coil, The winding width of the M coils gradually increases from the inside to the outside. When the coil width reaches the threshold value A, a single discontinuous coil groove is set thereon; when the coil width continues to increase to the threshold value B, from then on Two grooves are provided on it. 2 . The wireless charging receiving antenna structure according to claim 1 , wherein the coil is a double-layer winding coil. 3 . 3 . The wireless charging receiving antenna structure according to claim 1 , wherein the M=11; the N=4. 4 . 4 . The wireless charging receiving antenna structure according to claim 1 , wherein the coil groove is an intermittent arc-shaped groove, and the arc-shaped groove is concentric with the coil in which it is located. 5 . 5 . The wireless charging receiving antenna structure according to claim 1 , wherein the discontinuous arc grooves of the coil arranged on the outermost N turns of the coil are distributed in a radial equal arc. 6 . 6 . The wireless charging receiving antenna structure according to claim 1 , wherein the isolation region is a gap without filler or a gap filled with insulating material. 7 . 7 . The wireless charging receiving antenna structure according to claim 1 , wherein the width of the coil gradually increases from 0.9 mm to 1.3 mm from the inside to the outside, and the thickness of the coil is 40 μm to 70 μm; The width of the isolation region is 80 microns to 120 microns; the width of the coil trenches is 80 microns to 120 microns. 8. The wireless charging receiving antenna structure according to claim 1, wherein the coil grooves arranged on the outermost N turns of the coil further comprise: K coil grooves arranged on the outermost L circle of the coil, wherein L<N, K≥2; The J coil grooves are arranged on the secondary outer I turn of the coil, wherein L+I≤N, 1≤J<K. 9. The wireless charging receiving antenna structure of claim 1, wherein the substrate is a flexible circuit substrate.

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