CN109149782B

CN109149782B - Wireless charging device

Info

Publication number: CN109149782B
Application number: CN201710465076.5A
Authority: CN
Inventors: 吴铭洪; 吴基福; 曾安平; 杨文宾; 吴晧宇; 简凤龙; 陈茂军; 陈威宇; 黎韦均
Original assignee: TDK Taiwan Corp
Current assignee: TDK Taiwan Corp
Priority date: 2017-06-19
Filing date: 2017-06-19
Publication date: 2022-05-24
Anticipated expiration: 2037-06-19
Also published as: CN109149782A

Abstract

The present disclosure provides a wireless charging device, which includes a coil module, a magnetic field shielding member and a control circuit module. The coil module includes a coil formed with a plurality of turns. The magnetic field shield covers the coils of the coil module. The control circuit module is configured to be electrically connected with the coil of the coil module, wherein the control circuit module comprises a substrate and at least one electronic element embedded in the substrate. In the embodiment of the invention, at least one electronic element of the control circuit module is embedded in the substrate, so that the size of the control circuit module can be reduced, thereby being beneficial to the miniaturization of the whole wireless charging device and being suitable for being applied to electronic devices such as personal mobile devices, wearable devices and the like.

Description

Wireless charging device

Technical Field

The present invention relates to a wireless charging device; in particular, the present invention relates to a miniaturized wireless charging device suitable for use in an electronic device such as a personal mobile device or a wearable device.

Background

Along with science and technology development, electronic devices such as individual mobile device, wearable device are more and more diversified, and the product function combines network and mobile life, has promoted the convenience of life greatly, also makes electronic device have the trend of increasing to the demand of electric power simultaneously. In order to solve the power problem of the electronic device, a wireless charging system has been developed, which can be roughly divided into two types, one is a wireless charging system using Electromagnetic Induction (Electromagnetic Induction), and the other is a wireless charging system using Electromagnetic Resonance (Electromagnetic Resonance), wherein the wireless charging system using Electromagnetic Induction is more common.

A conventional wireless charging system using electromagnetic induction technology is shown in fig. 1, and includes a power transmitting terminal 1 disposed on a fixed platform (e.g., a charging pad, not shown) and a power receiving terminal 2 disposed on an electronic device (e.g., a mobile phone or a smart watch, not shown). The power transmitting terminal 1 includes a transmitting terminal coil 1A and a transmitting terminal core plate 1B, and the power receiving terminal 2 includes a receiving terminal coil 2A and a receiving terminal core plate 2B. When the power transmitting end 1 and the power receiving end 2 are close to each other, the electromagnetic field generated by the power passing through the transmitting end coil 1A is transmitted to the receiving end core plate 2B through the transmitting end core plate 1B, and the electromagnetic field can generate inductive power after passing through the receiving end coil 2A, so that the purpose of wireless charging is achieved. In some designs, the transmitting end iron core plate 1B and the receiving end iron core plate 2B may also be omitted.

Although existing wireless charging systems have been adequate to meet their needs, they have not yet been fully met. For example, the conventional wireless charging device disposed on an electronic device (i.e., a power receiving end) such as a personal mobile device or a wearable device has a large size, which hinders the miniaturization of the electronic device such as the personal mobile device or the wearable device.

Disclosure of Invention

In view of the above-mentioned conventional problems, it is an object of the present invention to provide a wireless charging device which is suitable for being applied to an electronic device such as a personal mobility device or a wearable device and which is small in size.

According to some embodiments, a wireless charging device is provided, which includes a coil module, a magnetic field shielding member and a control circuit module. The coil module includes a coil formed with a plurality of turns. The magnetic field shield covers the coils of the coil module. The control circuit module is configured to be electrically connected to the coil of the coil module, wherein the control circuit module includes a substrate and at least one electronic element embedded (embedded) in the substrate.

In some embodiments, the at least one electronic component is not exposed to any surface of the substrate of the control circuit module.

In some embodiments, the coil module is made of a flexible circuit board.

In some embodiments, the control circuit module further includes a plurality of wires embedded in the substrate and electrically connected to the at least one electronic component. The circuit forms a plurality of conductive terminals on a Surface of the substrate, and the conductive terminals are electrically connected to the coils of the coil module by a Surface Mount Technology (Surface Mount Technology).

In some embodiments, the coil module further includes a plurality of terminals exposed on at least one surface of the coil module and electrically connected to the coil and the at least one electronic component. The wireless charging device further comprises a plurality of matching elements electrically connected with the terminals.

In some embodiments, the control circuit module is disposed at the center of the coil module.

In some embodiments, the coil, the matching element, and the at least one electronic element of the control circuit module are sequentially arranged from outside to inside when viewed along a winding axis direction of the coil module.

In some embodiments, the magnetic field shield has an annular configuration corresponding to the shape of the coils of the coil module.

In some embodiments, the magnetic field shield and the control circuit module are disposed on the same surface of the coil module.

In some embodiments, the coil of the coil module is formed on the substrate of the control circuit module.

In the embodiment of the invention, at least one electronic element of the control circuit module is embedded in the substrate, so that the size of the control circuit module can be reduced, thereby being beneficial to the miniaturization of the whole wireless charging device and being suitable for being applied to electronic devices such as personal mobile devices, wearable devices and the like.

In order to make the aforementioned and other objects, features, and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

Fig. 1 shows a schematic diagram of a conventional wireless charging system.

Fig. 2 illustrates an exploded view of a wireless charging device according to some embodiments of the present invention.

Fig. 3A and 3B show an assembled top view and an assembled bottom view of the wireless charging device in fig. 2, respectively.

FIG. 4 illustrates a cross-sectional schematic diagram of a control circuit module according to some embodiments of the invention.

Fig. 5 is an exploded view of a wireless charging device according to further embodiments of the present invention.

Fig. 6A and 6B show an assembled top view and an assembled bottom view of the wireless charging device in fig. 5, respectively.

Fig. 7 is a schematic diagram illustrating the formation of coils of a coil module on a substrate of a control circuit module according to still other embodiments of the present invention.

Description of reference numerals:

1-power transmission end;

1A-a transmission end coil;

1B, conveying the end iron core plate;

2-electric power receiving end;

2A-a receiving end coil;

2B, receiving the end iron core plate;

10. 10 ', 10' wireless charging device;

100-coil module;

101-a substrate;

101A to the upper surface;

101B to the lower surface;

102-coil;

103-a terminal;

104-a matching element;

200-a magnetic field shield;

300-a control circuit module;

300A to the upper surface;

300B to the lower surface;

301 to a substrate;

301A-301D-resin layer;

302 electronic component/control chip;

302A main surface;

302B to the back;

3021-conductive bump;

3022 to a metal layer;

303. 304-conducting wire patterns;

305. 306-through electrodes;

307-electrode pad/conductive end;

308-electrode pads;

d1-direction of winding shaft;

d2-long axis direction;

e-dotted line;

p-adhesive element.

Detailed Description

The following describes embodiments of the present invention. This description is made for the purpose of illustrating the general principles of the invention and is not meant to limit the scope of the invention. The protection scope of the present invention is subject to the claims.

In the following description, the directions "up" and "down" are merely used to indicate relative positional relationships, and are not intended to limit the present invention. When a first element is referred to as being "on" a second element, it can be directly on the second element or be separated from the second element by one or more other elements. In the drawings or description, like or identical elements are provided with the same reference numerals. In the drawings, the shape or thickness of the embodiments may be exaggerated for simplicity or convenience of illustration. Also, elements not shown or described in the drawings are of a form known to those skilled in the art.

Referring to fig. 2, fig. 3A and fig. 3B, a wireless charging device 10 according to some embodiments of the present invention is, for example, a power receiving end of a wireless charging system, which can be disposed on an electronic device (not shown) such as a personal mobile device (e.g., a mobile phone, a tablet computer or a notebook computer), a wearable device (e.g., a smart watch or a bracelet) to provide a wireless charging function. The wireless charging device 10 mainly includes a coil module 100, a magnetic shielding member 200 and a control circuit module 300.

The coil module 100 includes at least one coil 102 forming a plurality of turns for generating a current by electromagnetic induction. According to some embodiments, the coil module 100 is made of a Flexible Printed Circuit Board (FPC) including a substrate 101 made of an insulating material (e.g., Polyamide (Polyamide) or polyethylene terephthalate (Polyester)), and a coil 102 made of a metal material (e.g., copper) formed on at least one surface of the substrate 101. According to some embodiments, the coil module 100 may also be made of a Printed Circuit Board (Printed Circuit Board).

In the embodiment of fig. 2 and 3B, a coil 102 is formed on the upper surface 101A and the lower surface 101B of the substrate 101. Although not shown, the two coils 102 on the upper and

lower surfaces

101A and 101B can be electrically connected through a circuit inside the substrate 101. According to some embodiments, only one coil 102 may be formed on the upper surface 101A or the lower surface 101B of the substrate 101. The number and number of turns of the coils 102 may be adjusted according to the power requirements of the electronic device. In addition, a cover film (not shown) may be formed on the upper and

lower surfaces

101A and 101B of the substrate 101 above the coil 102 to protect the coil 102. The cover film may have the same or similar material as the substrate 101.

The magnetic field shielding member 200 is disposed above the coil 102 of the coil module 100 to prevent leakage of the electromagnetic field. For example, when the power transmitting terminal (e.g., a charging pad) of the wireless charging system is disposed at one side of the lower surface 101B of the substrate 101 of the coil module 100, the magnetic field shielding member 200 may be disposed above the coil 102 (fig. 2) of the upper surface 101A of the substrate 101 to prevent the electromagnetic field from leaking upwards, whereas the magnetic field shielding member 200 may be disposed above the coil 102 of the lower surface 101B of the substrate 101 to prevent the electromagnetic field from leaking downwards. According to some embodiments, the magnetic field shielding member 200 may be made of a conductive material with high magnetic permeability or a ferromagnetic material and has a ring structure corresponding to the shape of the coil 102, and the coil 102 may be designed to have a square, rectangular, circular or other polygonal shape, depending on the shape of the substrate 101 or the application requirements. In addition, the magnetic field shielding member 200 may be fixed to the coil 102 by an adhesive member P, which may include a double-sided tape or other optional adhesive material.

The control circuit module 300 is disposed on a surface of the substrate 101 of the coil module 100 and electrically connected to an end (not shown) of the coil 102, for receiving the induced voltage generated by the coil 102 and rectifying and stabilizing the induced voltage to generate a regulated voltage. In the embodiments of fig. 2 and 3A, the control circuit module 300 and the magnetic field shielding member 200 are disposed on the same surface (upper surface 101A) of the substrate 101 of the coil module 100. However, the control circuit module 300 and the magnetic field shielding member 200 may be disposed on the upper and

lower surfaces

101A and 101B of the substrate 101 of the coil module 100, respectively, based on different configurations of the circuit inside the substrate 101 of the coil module 100.

Fig. 4 illustrates a cross-sectional schematic diagram of a control circuit module 300 according to some embodiments of the invention. As shown in fig. 4, the control circuit module 300 mainly includes a substrate 301 and at least one electronic component 302 embedded in the substrate 301. The electronic component 302 is not exposed to any surface of the substrate 301. According to some embodiments, the electronic component 302 is a control chip for determining the voltage generated by the control circuit module 300. The substrate 301 is composed of laminated resin layers (for example, thermoplastic resin or thermosetting resin) 301A to 301D. The control chip 302 is embedded between the resin layers 301A and 301B, and is electrically connected to the

electrode pads

307, 308 exposed on the upper surface 300A and the lower surface 300B of the control circuit module 300 via various types of

wiring patterns

303, 304 and through

electrodes

305, 306 formed in the resin layers 301A to 301D. Although not shown, a passivation layer (e.g., a solder mask) may be respectively covered on the upper and

lower surfaces

300A and 300B of the control circuit module 300, and the

electrode pads

307 and 308 are exposed to the outside through the openings on the passivation layer. The various structures of the control circuit module 300 can be completed by the existing semiconductor manufacturing technology, and are not described herein again.

According to some embodiments, at least one of the exposed electrode pads 308 may also have a capacitor, a resistor, or other passive components mounted thereon for cooperating with the control chip 302 to control the induced voltage. According to some embodiments, capacitors, resistors or other passive elements may also be embedded in the substrate 301 (i.e., not exposed on the outermost surface of the substrate 301), and electrically connected to the control chip 302 by the

wiring patterns

303, 304 and/or the through

electrodes

305, 306.

It should be understood that the control chip 302 is embedded between the resin layers 301A and 301B in a bare chip state, so that the thickness of the package of the conventional control chip 302 can be omitted. In addition, a conductive bump 3021 may be formed on a pad electrode (not shown) on the main surface 302A of the control chip 302 by plating, sputtering, or soldering, and the material of the conductive bump 3021 includes gold, silver, copper, nickel, tin, chromium, nickel-chromium alloy, solder, and the like. After the control chip 302 is disposed on the resin layer 301A, the conductive bump 3021 may be exposed from the resin layer 301A by a method such as grinding, etching, or laser irradiation. Thus, the control chip 302 can be electrically connected to the electrode pads 307 on the lower surface 300B of the circuit module 300 via the conductive bumps 3021, the wiring patterns 304 embedded in the resin layer 301C of the substrate 301, and the through electrodes 305 (wherein the electrode pads 307 can also be regarded as conductive ends formed on the lower surface 300B by the internal circuit composed of the wiring patterns 304 and the through electrodes 305).

Further, the electrode pads 307 (conductive terminals) on the lower Surface 300B of the control circuit module 300 may be electrically connected to terminals (not shown) of the coil 102 exposed on the upper Surface 101A of the substrate 101 of the coil module 100 by a Surface Mount Technology (Surface Mount Technology). The surface mounting technique includes electrically connecting the electrode pad 307 and the terminal of the coil 102 by solder balls, solder paste, solder, or the like by a soldering method. As can be seen from fig. 2 and 3A, when viewed along a direction perpendicular to the upper surface 300A of the control circuit module 300, the solder joints between the lower surface 300B of the control circuit module 300 and the end points of the coil 102 of the coil module 100 are not exposed, so that the chances of short circuit and electromagnetic interference are reduced.

As shown in fig. 4, a metal layer 3022 may be formed on the back side 302B of the control chip 302. The metal layer 3022 and the through electrode 306 and the electrode pad 308 connected thereto may serve as a heat dissipation path for heat generated during the operation of the control chip 302. The metal layer 3022 also prevents the back surface 302B of the control chip 302 from cracking, and improves the structural strength and reliability of the control chip 302.

In the above embodiment, the control circuit module 300 has at least one electronic component (e.g., the control chip 302, the capacitor, the resistor, or other passive components) embedded in the substrate 301, so that the space inside the substrate 301 can be fully utilized, and the area of the outermost surface of the substrate 301 can be reduced, thereby achieving the miniaturization of the control circuit module 300. As shown in fig. 2 and fig. 3A, the miniaturized control circuit module 300 can be disposed at the center of the coil 102 of the coil module 100 to effectively utilize the central region of the coil 102 on the substrate 101, so that the whole wireless charging device 10 can be miniaturized and applied to electronic devices such as personal mobile devices and wearable devices.

Referring to fig. 2 and fig. 3A, a plurality of exposed terminals 103 may also be formed on the upper surface 101A of the substrate 101 of the coil module 100 for electrically connecting a rechargeable battery or a circuit board of an electronic device and providing the power generated by the wireless charging device 10 to the electronic device. The terminals 103 are electrically connected to the coil 102 and the electronic components such as the control chip 302 of the control circuit module 300 through the circuit inside the substrate 101.

According to some embodiments, the wireless charging device 10 also includes a plurality of matching elements (matching components) 104, such as capacitors and resistors, electrically connected to the terminals 103 of the portion (the matching elements 104 in fig. 2 and 3A shield the terminals 103 underneath due to the perspective). The matching element 104 may be used to modulate the magnitude of the induced voltage generated by the wireless charging device 10. In addition, when viewed along a winding axis direction D1 of the coil 102 of the coil module 100, the coil 102, the matching element 104, and the control circuit module 300 (and the control chip 302 therein) are arranged in sequence from outside to inside, so that the configuration can shorten the line distance between the coil 102 and the control chip 302, thereby preventing the induced voltage generated by the wireless charging device 10 from being reduced due to the impedance of the line itself.

Fig. 5 illustrates an exploded view of a wireless charging device 10' according to further embodiments of the present invention. Fig. 6A and 6B show an assembled top view and a assembled bottom view of the wireless charging device 10' in fig. 5, respectively. In the embodiments of fig. 5, 6A and 6B, the components or modules of the wireless charging device 10' are the same as those of the embodiment (the wireless charging device 10) of fig. 2 to 4, so the same reference numerals are used to indicate the components or modules, and repeated descriptions are omitted. The difference between the wireless charging device 10' and the wireless charging device 10 is that the control circuit module 300 is disposed on one side of the coil 102 of the coil module 100, and the terminal 103 and the matching element 104 to be exposed on the upper surface 101A of the substrate 101 of the coil module 100 are also disposed on the side of the coil 102 where the control circuit module 300 is located.

With the above configuration, the whole wireless charging device 10' can also be miniaturized, and is suitable for application to electronic devices such as personal mobile devices, wearable devices, and the like. In addition, in the embodiment of fig. 5, when viewed along a winding axis direction D1 of the coil 102 of the coil module 100, the coil 102, the matching element 104, and the control circuit module 300 (and the control chip 302 therein) are arranged in sequence along a long axis direction D2 of the substrate 101 of the coil module 100, so that the configuration can also shorten the line distance between the coil 102 and the control chip 302, thereby preventing the induced voltage generated by the wireless charging device 10' from being reduced due to the impedance of the line itself.

According to some embodiments, if the wireless charging device 10' is further reduced in size, the coil module 100 made of the flexible circuit board may be folded along the dashed line E shown in fig. 6A and 6B, and the coil 102 of the coil module 100 and the control circuit module 300 (and the matching element 104) are overlapped. In addition, in this folded state, the magnetic field shielding member 200 may be disposed above the coil 102 on the upper surface 101A or above the coil 102 on the lower surface 101B of the substrate 101 of the coil module 100 according to the position of the power transmitting terminal (e.g., a charging pad) of the wireless charging system to prevent electromagnetic wave leakage. According to some embodiments, the magnetic field shield 200 may have a complete plate structure (fig. 5 and 6A).

Fig. 7 shows a schematic diagram of a wireless charging device 10 "according to yet other embodiments of the invention. In the embodiment of fig. 7, the coil 102 of the coil module 100 may be formed directly on the substrate 301 of the control circuit module 300 (e.g., on the upper and

lower surfaces

300A and 300B of the control circuit module 300). The structure of the control circuit module 300 is the same as or similar to that of the embodiment of fig. 4, and only the internal structural layers and circuits of the control circuit module 300 are omitted from fig. 7 for simplicity.

According to some embodiments, the two multi-turn coils 102 formed on the upper and

lower surfaces

300A and 300B of the control circuit module 300 may be electrically connected to the control chip 302 embedded in the substrate 301 of the control circuit module 300 through the internal and/or external circuits (not shown) of the control circuit module 300 to form a wireless charging device 10 ″. The wireless charging device 10 ″ also includes a magnetic shielding member 200, which can be covered on the circuit 102 on the upper surface 300A or the lower surface 300B of the circuit module 300 by an adhesive element P to prevent electromagnetic wave leakage. Although not shown, the wireless charging device 10 ″ may also include the matching element 104 and the terminal 103 formed on the upper surface 300A or the lower surface 300B of the circuit module 300.

According to some embodiments, the coil 102 of the coil module 100 may also be formed when the structural layers and circuits of the substrate 301 of the control circuit module 300 are formed, so that the coil 102 is embedded in the substrate 301 together with the control chip 302.

In summary, in the embodiment of the invention, at least one electronic component of the control circuit module is embedded in the substrate, so that the size of the control circuit module can be reduced, which is favorable for miniaturization of the whole wireless charging device and is suitable for being applied to electronic devices such as personal mobile devices and wearable devices.

Although the present invention has been described with reference to the above embodiments, it should be understood that the invention is not limited thereto. Those skilled in the art to which the invention pertains will readily appreciate that numerous modifications and adaptations may be made without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention is subject to the claims.

Claims

1. A wireless charging device, comprising:

a coil module including a coil formed with a plurality of turns;

a magnetic field shielding member covering the coil; and

a control circuit module configured to electrically connect to the coil, wherein the control circuit module includes a substrate and at least one electronic component embedded in the substrate, the coil of the coil module is directly formed on the substrate of the control circuit module, the coil and the electronic component are located on the same side of the magnetic field shielding member, and the at least one electronic component is disposed in the center of the coil module when viewed along a winding axis direction of the coil module.

2. The wireless charging device of claim 1, wherein the at least one electronic component is not exposed on any surface of the substrate.

3. The wireless charging device of claim 1, wherein the coil module is made of a flexible circuit board.

4. The wireless charging device of claim 1, wherein the control circuit module further comprises a plurality of wires embedded in the substrate and electrically connected to the at least one electronic component, the wires form a plurality of conductive terminals on a surface of the substrate, and the conductive terminals are electrically connected to the coil of the coil module by a surface mount technology.

5. The wireless charging device of claim 4, wherein the coil module further comprises a plurality of terminals exposed on at least one surface of the coil module and electrically connecting the coil and the at least one electronic component, the wireless charging device further comprising a plurality of matching elements electrically connected to the terminals.

6. The wireless charging device of claim 5, wherein the coil, the matching element, and the at least one electronic element of the control circuit module are sequentially arranged from outside to inside when viewed along a winding axis direction of the coil module.

7. The wireless charging device of any one of claims 1 to 6, wherein the control circuit module is disposed at a center of the coil module.

8. The wireless charging device of claim 7, wherein the magnetic field shielding member has a ring-shaped structure corresponding to the shape of the coil.

9. The wireless charging device of claim 7, wherein the magnetic field shielding member and the control circuit module are disposed on the same surface of the coil module.

10. The wireless charging device of claim 1, wherein the magnetic field shielding member, the coil module and the control circuit module are in an overlapping state.