A wireless charging device with a TX coil integrated on a driver PCB

Abstract

This utility model relates to the field of wireless charging technology, specifically to a wireless charging device with a TX coil integrated on a driver PCB, comprising: a driver PCB board; a first coil layer and a second coil layer stacked on top of the driver PCB board; an input coil formed on the first coil layer by printed circuitry; and an output coil formed on the second coil layer by printed circuitry. Addressing the problem of relatively complex and lengthy processes for the coil portion in existing wireless charging devices, this invention directly fabricates the input and output coils through printed circuitry during PCB board manufacturing. This eliminates the need to purchase coils, coil supports, and other materials during production, and avoids additional coil assembly and soldering processes, thus optimizing the production process. Furthermore, because the coils are integrated onto the PCB board via printed circuitry, the overall product size is smaller and lighter.

Description

Technical Field

[0001] This utility model relates to the field of wireless charging technology, specifically to a wireless charging device in which a TX coil is integrated on a driver PCB. Background Technology

[0002] Wireless charging, also known as inductive charging or contactless inductive charging, utilizes near-field induction, or inductive coupling, to transfer energy from a power supply device (charger) to the user. Its core technology typically involves a controller that manipulates a TX coil to oscillate at high frequency, generating alternating electromagnetic signals that transmit energy in space. Therefore, wireless charging modules on the market generally consist of a coil, a coil support, a driver module, and a housing.

[0003] For example, Chinese patent CN202110779764.5 discloses a wireless transmitting coil, including a mounting plate, a circuit board, and a coil body. The circuit board is fixedly connected to the upper surface of the mounting plate, and the coil body is fixedly connected to the upper surface of the circuit board. A heat dissipation mechanism is fixedly connected to the lower surface of the mounting plate, and a pressing mechanism is fixedly connected to the upper surface of the coil body. The heat dissipation mechanism includes a heat dissipation vent on the lower surface of the mounting plate, a heat sink fixedly connected inside the vent and to the lower surface of the circuit board, and a positioning cover fixedly connected to the lower surface of the mounting plate. A support plate is fixedly connected inside the positioning cover. This wireless transmitting coil and wireless charger, thanks to the heat dissipation mechanism, can achieve dual heat dissipation when the coil body is working, preventing overheating and affecting the heat dissipation effect of the coil body. The left and right sides of the stabilizing mechanism on the lower side of the outer casing allow the entire wireless charger to be fixed on a desktop.

[0004] However, in actual implementation, the inventors discovered that the coils in this type of technical solution are usually formed by independently winding copper wire. The coil winding process is relatively complex, the material cost is high, and different manufacturers using different coils produce results with varying inductance, internal resistance, and other electrical parameters, which is detrimental to production. Furthermore, during the assembly process of the coil and support frame, because the coil is fixed to the support frame by manual gluing, and the coil's wiring harness terminals are connected to the drive module by welding, the terminals of the coil and support frame as a whole cannot be automatically welded or assembled. This results in a complex module production process, making automated production difficult. Utility Model Content

[0005] In view of the above-mentioned problems in the prior art, a wireless charging device in which the TX coil is integrated on the driver PCB is provided.

[0006] The specific technical solution is as follows:

[0007] A wireless charging device with a TX coil integrated on a driver PCB includes a driver PCB board;

[0008] A first coil layer and a second coil layer are stacked on top of the driving PCB board;

[0009] An input coil is formed on the first coil layer by a printed circuit.

[0010] An output coil is formed on the second coil layer by a printed circuit.

[0011] The driving PCB board is equipped with a driving circuit.

[0012] The input coil and the output coil are respectively connected to the driving circuit through vias on the PCB board.

[0013] On the other hand, the first coil layer is located above the second coil layer;

[0014] The second coil layer is located above the top of the drive PCB board.

[0015] On the other hand, a magnetic shielding sheet is attached between the second coil layer and the driving PCB board;

[0016] The gap between the second coil layer and the driving PCB board is greater than 0.5 mm.

[0017] On the other hand, the number of turns of the input coil and the output coil are 5.5 turns each.

[0018] On the other hand, the input coil and the output coil have dimensions of 80mm in length and 65mm in width when viewed from above.

[0019] On the other hand, a temperature sampling resistor is provided above the first coil layer corresponding to the center position of the input coil, and the temperature sampling resistor is connected to the driving circuit.

[0020] On the other hand, after the circuit of the input coil is wound on the first coil layer, it is connected to the second coil layer for winding via the coil via in the PCB via.

[0021] On the other hand, the circuit consists of 10 wires wound in parallel.

[0022] On the other hand, the line width of the line is 0.34 mm.

[0023] On the other hand, the components and terminals of the driving circuit are located on the lower surface of the PCB driving board.

[0024] The above technical solution has the following advantages or beneficial effects:

[0025] To address the issue of relatively complex and lengthy processes in the coil component of existing wireless charging devices, this solution replaces the copper wire-wound coil with a coil formed by printed circuitry on a PCB board. This eliminates the steps of copper wire winding, coil support soldering, and assembling the coil, support, and driver board. Instead, the coil is directly fabricated during PCB manufacturing through printed circuitry. This eliminates the need to purchase coils and coil supports during production and removes the additional coil assembly and soldering steps, thus optimizing the production process. Furthermore, because the coil is integrated onto the PCB board via printed circuitry, the overall product is smaller and lighter. Attached Figure Description

[0026] Embodiments of the present invention will be described more fully with reference to the accompanying drawings. However, the accompanying drawings are for illustration and explanation only and do not constitute a limitation on the scope of the present invention.

[0027] Figure 1 This is an overall schematic diagram of an embodiment of the present utility model;

[0028] Figure 2 This is a schematic diagram of an embodiment of the present utility model. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention.

[0032] This utility model includes:

[0033] A wireless charging device with a TX coil integrated on a driver PCB includes a driver PCB 1.

[0034] A first coil layer 2 and a second coil layer 3 are stacked on top of the driving PCB board 1;

[0035] An input coil 4 is formed on the first coil layer 2 by a printed circuit;

[0036] An output coil 6 is formed on the second coil layer 3 by a printed circuit.

[0037] A driving circuit 7 is provided on the driving PCB board 1;

[0038] The input coil 4 and the output coil 6 are connected to the drive circuit 7 through vias on the PCB board.

[0039] Specifically, in response to the problem that the coil part of the existing wireless charging device has a relatively complex process and a long process, this solution replaces the copper wire wound coil with a coil formed by printed circuit on the PCB board, which eliminates the steps of copper wire winding, welding coil bracket, and assembling coil, bracket and driver board, making the structure compact and the process simple.

[0040] Specifically, the aforementioned wireless charging device has a main structure composed of multiple layers of PCB boards, which include multiple substrates, such as fiberglass. Each layer has corresponding printed circuits formed using processes such as silver paste printing or copper etching, based on the wiring design, to perform different functions. These circuits are determined according to requirements; for example, existing wireless charging circuits include AC / DC circuits, charging control circuits, and drive circuits, etc.

[0041] At the top of the multilayer PCB board, two circuit board layers are selected as the first coil layer 2 and the second coil layer 3. These two layers generally do not carry other functional circuits, such as signal circuits for charging detection or drive circuits, but are used to carry the coil parts, including the input coil 4 and the output coil 6. However, during the manufacturing process, the above structure is manufactured together with the multilayer board, and the whole is also presented as a single multilayer board. The driver circuit board 1, the first coil layer 2, and the second coil layer 3 are only a description of the functional areas in the direction of the layers.

[0042] Based on the above settings, the steps of winding the coil, installing it on the bracket, and connecting and fixing the bracket to the drive board can be eliminated, saving processes and simplifying the structural design. It can be installed in any type of housing.

[0043] In one embodiment, the first coil layer 2 is located above the second coil layer 3;

[0044] The second coil layer 3 is located above the top of the drive PCB board 1.

[0045] Specifically, in order to achieve a better layout, the wiring structure was designed in this solution. The output coil 6 was formed on the driver PCB board 1 with the normal drive circuit, and the second coil layer 3 was made by layout. Then, the first coil layer 2 was formed by wiring above the second coil layer 3.

[0046] In one embodiment, a magnetic shielding sheet is attached between the second coil layer 3 and the driving PCB board 1;

[0047] The gap between the second coil layer 3 and the driving PCB board 1 is greater than 0.5mm.

[0048] Specifically, since the principle of wireless charging devices is to achieve wireless energy transfer through induced current, a corresponding induced current will be generated in the coupled closed loop. Based on the above layout, when the input coil 4 and the output coil 6 are working, a corresponding current is easily generated in the driving circuit below.

[0049] To solve this problem, in this solution, a magnetic shielding sheet is attached between the second coil layer 2 and the driving PCB board 1 during the board manufacturing process. Based on this magnetic shielding sheet, the gap between the second coil layer 2 and the driving PCB board 1 is controlled to be greater than 0.5mm, thereby isolating the magnetic field generated by the coil.

[0050] In one embodiment, the input coil 4 and the output coil 6 each have 5.5 turns.

[0051] In one embodiment, the input coil 4 and the output coil 6 have dimensions of 80 mm in length and 65 mm in width when viewed from above.

[0052] Specifically, since the wireless charging module transmits energy by generating alternating signals through the oscillation of coil L and capacitor C during operation, the size of coil L is the main factor affecting the oscillation effect. According to the formula L = (u * N² * A) / I, where L is the coil inductance, u is the coil permeability, N is the number of turns, A is the cross-sectional area of ​​the coil, and I is the average magnetic path length, it can be seen that changing the number of turns N changes the magnitude of inductance L. According to the formula, when the coil has 11 turns, the inductance is 10.5 ± 0.5 uH, satisfying the oscillation condition for L.

[0053] Based on the above calculation process, the number of turns of the input coil 4 and the output coil 6 were selected to be 5.5 turns respectively in this scheme. During the wiring process, the first end of the line of the input coil 4 first passes through the second coil layer 3 through the via to reach the first coil layer 2. After being wound on the first coil layer 2, it extends downward through the coil via in the PCB via and connects to the second coil layer 3 for winding, thereby forming the output coil 6, and then connects to the circuit below through the via.

[0054] Accordingly, to meet the relevant charging power requirements, the circuit consists of 10 parallel wires with a wire width of 0.34mm.

[0055] The substrate copper thickness is greater than 4 oz, and the coil uses 10 parallel traces with a width of 0.34 mm, with 5.5 turns wound on each coil PCB layer. Since the coil layer copper thickness is greater than 4 oz, the total diameter of the 10 coils is 3.4 mm, and its maximum conduction current is greater than 10A, which fully meets the overcurrent requirement of 2A to 3A for a 15W charging coil.

[0056] In one embodiment, a temperature sampling resistor is provided above the first coil layer 2 at the center position corresponding to the input coil 4, and the temperature sampling resistor is connected to the drive circuit.

[0057] Specifically, in order to detect the temperature of the coil, in this embodiment, a temperature sampling resistor is provided above the first coil layer 2 at the center position corresponding to the input coil 4. The temperature sampling resistor is attached above the first coil layer 2 and is used to detect the heating of the coil.

[0058] The pins of the temperature sampling resistor pass through vias through the first coil layer 2 and the second coil layer 3 to reach the drive circuit below, which is used to control the over-temperature detection circuit.

[0059] In one embodiment, the components and terminals of the drive circuit 7 are located on the lower surface of the PCB drive board 1.

[0060] Specifically, to achieve better wiring performance, in this embodiment, based on multi-layer wiring in the PCB driver board 1, various components and terminals are brought to the lower surface of the bottom layer board through wiring and vias. Components include discrete devices and packaged integrated circuits, and terminals are wiring terminals used to connect external cables, slots, and other structures.

[0061] This solution replaces the coil components originally soldered onto the driver PCB by adding two layers of coil PCB on the main PCB. This eliminates the need for additional coil procurement and testing in terms of material control, thus optimizing hardware costs. Furthermore, it eliminates the need for additional coil assembly and soldering processes, streamlining the production process. Since the coil is integrated onto the PCB substrate, there are no external coils or coil supports, resulting in a smaller and lighter wireless charging module. Because the coil is integrated onto the PCB, there are no manual coil positioning or bonding steps, allowing for fully automated production and significantly improving efficiency.

[0062] This design uses a single substrate for both the coil and the driver board, allowing for miniaturization. The top two layers of the PCB have wiring, and the coil turns and inductance are identical to those of discrete coils, saving on coil costs. Furthermore, the wireless charging module production process eliminates the need for manual external coil mounting and machine soldering, reducing component and assembly costs. Additionally, since the coil is laid out on the PCB, parameter consistency is easier to control during production.

[0063] This solution uses a 6-layer PCB substrate with a thickness of no more than 3mm. The top coil layer can serve as the top cover layer of the entire module, directly contacting and charging the RX receiver of mobile phones, etc. Compared with traditional coils, no coil support is needed below the coil, which can greatly reduce the charging distance between TX and RX, and save the cost of coil support and top cover plate. All electronic components of the wireless charger are soldered to the bottom layer of the PCB substrate using SMT, reducing the module thickness, overall size and weight, which is beneficial to the miniaturization and lightweight design of the entire vehicle.

[0064] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A wireless charging device with a TX coil integrated on a driving PCB, characterized in that, Including the driver PCB board; A first coil layer and a second coil layer are stacked on top of the driving PCB board; An input coil is formed on the first coil layer by a printed circuit. An output coil is formed on the second coil layer by a printed circuit. The driving PCB board is equipped with a driving circuit. The input coil and the output coil are respectively connected to the driving circuit through through-holes on the PCB board; The first coil layer is located above the second coil layer; The second coil layer is located above the top of the drive PCB board; The first end of the input coil circuit first passes through the second coil layer through a via to reach the first coil layer. After being wound on the first coil layer, it extends downward through the coil via in the PCB via and connects to the second coil layer for winding, thereby forming the output coil. It is then connected to the circuit below through a via.

2. The wireless charging device of claim 1, wherein, A magnetic shielding sheet is attached between the second coil layer and the driving PCB board; The gap between the second coil layer and the driving PCB board is greater than 0.5 mm.

3. The wireless charging device of claim 1, wherein, The input coil and the output coil each have 5.5 turns.

4. The wireless charging device of claim 1, wherein, The input coil and the output coil have dimensions of 80mm in length and 65mm in width when viewed from above.

5. The wireless charging device of claim 1, wherein, A temperature sampling resistor is provided above the first coil layer at the center position corresponding to the input coil, and the temperature sampling resistor is connected to the driving circuit.

6. The wireless charging device of claim 1, wherein, After the input coil is wound on the first coil layer, it is connected to the second coil layer for winding via the coil via in the PCB via.

7. The wireless charging device of claim 6, wherein, The circuit consists of 10 parallel wires wound together.

8. The wireless charging device of claim 6, wherein, The line width is 0.34 mm.

9. The wireless charging device of claim 1, wherein, The components and terminals of the driving circuit are located on the lower surface of the driving PCB board.

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