TWI885579B - Wireless charging device - Google Patents

Abstract

A wireless charging device includes a first substrate, at least one charging coil, a second substrate, a comb filter, at least one thermistor and a controller. The at least one charging coil is disposed on the first substrate. The second substrate is disposed above the at least one charging coil. The comb filter is disposed on the second substrate, and a projection area of the comb filter in a stacking direction at least partially overlaps the at least one charging coil. The at least one thermistor is disposed at the comb filter. The controller is connected to the at least one charging coil and connected to the at least one thermistor through a part of the comb filter.

Description

Wireless charging device

The present invention relates to a wireless charging device.

Since it is a trend that both electric cars and traditional cars have already put wireless charging modules (WCM) for mobile phones into standard car accessories, the advantage is that it does not need to be connected to the mobile phone separately and saves the cumbersome action of plugging in the plug. Since the wireless charging module for mobile phones transmits power at the operating frequency of 112 to 128 kHz (default is 127.772kHz) defined by Qi, and the car is a closed and limited space, it will naturally produce many problems such as electromagnetic interference (EMI).

In view of the above, the present invention provides a wireless charging device.

According to an embodiment of the present invention, a wireless charging device comprises a first substrate, at least one charging coil, a second substrate, a comb filter, at least one thermistor and a controller. The at least one charging coil is disposed on the first substrate. The second substrate is disposed above the at least one charging coil. The comb filter is disposed on the second substrate, and the projection area in the stacking direction at least partially overlaps the at least one charging coil. The at least one thermistor is disposed on the comb filter. The controller is connected to the at least one charging coil and is connected to the at least one thermistor through a portion of the comb filter.

Through the above structure, the wireless charging device disclosed in this case can reduce the electromagnetic interference problem that the charging coil may generate to the surrounding environment during charging by setting a substrate with a comb filter above the charging coil. The wireless charging device of this case can sense whether the mobile phone is overheated during charging by setting a thermistor in the comb filter, and because the thermistor is connected to the controller that receives the signal through a part of the comb filter, the overall circuit connection of the wireless charging device is simpler.

The above description of the disclosed content and the following description of the implementation method are used to demonstrate and explain the spirit and principle of the present invention, and provide a further explanation of the scope of the patent application of the present invention.

1: Wireless charging device

11: First substrate

12: Second substrate

121: First page

122: Second side

123:Through hole

13: Charging coil

14: Comb filter

141: Comb structure

1411: Connection part

142: Grounding structure

15: Thermistor

16: Controller

17:Metal connectors

18: Insulation layer

19: Near Field Communication Coil

D: Stacking direction

d1: line width

d2: line spacing

A: Area

Figure 1 is a schematic diagram of the structure of a wireless charging device according to an embodiment of the present invention.

FIG2 shows an implementation of a charging coil of a wireless charging device disposed on a first substrate according to an embodiment of the present invention.

FIG3 shows an implementation of a comb filter disposed on the second substrate of a wireless charging device according to an embodiment of the present invention.

FIG4 is a schematic diagram of a charging coil of a wireless charging device disposed on a first substrate according to an embodiment of the present invention.

FIG5 is a schematic diagram of a comb filter disposed on the second substrate of a wireless charging device according to an embodiment of the present invention.

Figure 6 is a partial enlarged view of area A in Figure 5.

Figure 7 shows the corresponding position relationship between the thermistor and the charging coil of a wireless charging device according to an embodiment of the present invention.

FIG8 is a plan view of the second substrate of a wireless charging device according to another embodiment of the present invention.

FIG9 is a schematic diagram of the structure of a wireless charging device according to another embodiment of the present invention.

The detailed features and advantages of the present invention are described in detail in the following implementation method. The content is sufficient for anyone familiar with the relevant technology to understand the technical content of the present invention and implement it accordingly. According to the content disclosed in this specification, the scope of the patent application and the drawings, anyone familiar with the relevant technology can easily understand the relevant purposes and advantages of the present invention. The following embodiments are to further illustrate the viewpoints of the present invention, but do not limit the scope of the present invention by any viewpoint.

Please refer to FIG. 1, which is a schematic diagram of the structure of a wireless charging device according to an embodiment of the present invention. As shown in FIG. 1, the wireless charging device 1 includes a first substrate 11, a second substrate 12, at least one charging coil 13, a comb filter 14, at least one thermistor 15 and a controller 16. At least one charging coil 13 is disposed on the first substrate 11. The second substrate 12 is disposed above the at least one charging coil 13. The comb filter 14 is disposed on the second substrate 12, and the projection area in the stacking direction D at least partially overlaps the at least one charging coil 13. At least one thermistor 15 is disposed on the comb filter 14. The controller 16 is connected to the at least one charging coil 13, and is connected to the at least one thermistor 15 through a portion of the comb filter 14.

In this example, the second substrate 12 has a first surface 121, a second surface 122 and a plurality of through holes 123, wherein the first surface 121 faces the charging coil 13. The wireless charging device 1 may further include a plurality of metal connectors 17. The metal connectors 17 are disposed in the plurality of through holes 123, connected to the comb filter 14 and used for grounding, for example, by connecting to the chassis ground or to a ground wire. The metal connectors 17 may also serve as a support member for spacing the second substrate 12 and the charging coil 13 from each other. In addition, although the wireless charging device 1 described in this example uses the metal connector 17 to ground the comb filter 14 and support the second substrate 12, in other embodiments, the comb filter 14 can be grounded by other means, and/or the second substrate 12 and the charging coil 13 can be separated from each other by other supporting members.

The first substrate 11 may include a layer with shielding capability to prevent the charging coil 13 from generating electromagnetic interference to other electronic devices underneath during operation. Please refer to FIG. 2, which is an embodiment of a charging coil of a wireless charging device arranged on the first substrate according to an embodiment of the present invention. As shown in FIG. 2, in this embodiment, the number of charging coils 13 arranged on the first substrate 11 is 1, and the first substrate 11 has a wiring area covered by the charging coil 13 (i.e., an annular area covered by the charging coil 13) and a non-wiring area not covered by the charging coil 13 (i.e., a central area surrounded by the charging coil 13).

A comb filter 14 is disposed on the first surface 121 of the second substrate 12 facing the charging coil 13. Please refer to FIG. 3 in conjunction with FIG. 1 and FIG. 2. FIG. 3 is an embodiment of a comb filter disposed on the second substrate of a wireless charging device according to an embodiment of the present invention. As shown in FIG. 3, the comb filter 14 includes a comb structure 141 and a grounding structure 142. The projection area of the comb structure 141 in the stacking direction D at least partially overlaps the at least one charging coil 13. The grounding structure 142 is connected to the comb structure 141 and the metal connector 17, and is located at the periphery of the comb structure 141. The comb-shaped structure 141 includes a plurality of wires, and the thermistor 15 is disposed on one of the wires of the comb-shaped structure 141, and is preferably disposed above the non-wiring area of the first substrate 11, that is, above the central area surrounded by the charging coil 13.

The thermistor 15 can produce a corresponding change in resistance value based on the temperature change of the second substrate 12. The thermistor 15 can have a negative temperature coefficient (NTC) or a positive temperature coefficient (PTC), wherein the resistance value of the thermistor with a negative temperature coefficient decreases as the ambient temperature increases, and the resistance value of the thermistor with a positive temperature coefficient increases as the ambient temperature increases. The thermistor 15 described below is based on a type with a negative temperature coefficient, but the present case is not limited to this. The controller 16 can have data receiving, recording, computing, storing and outputting functions, such as including a microcontroller, a central processing unit, a programmable logic controller, etc. The controller 16 is connected to the thermistor 15 through a connecting portion 1411 of the comb structure 141 to read the resistance change of the thermistor 15 and obtain the current temperature of the second substrate 12 accordingly. When the controller 16 determines that the current temperature of the second substrate 12 is greater than a preset temperature, it means that the temperature of the mobile phone waiting for charging is too high, and the controller 16 can control the charging coil to reduce the charging power or stop charging.

The present invention does not limit the number of charging coils and thermistors, but preferably, the number of thermistors and the number of charging coils can be the same. The number of thermistors and charging coils described below is 3 as an example. Please refer to Figure 4, which is a schematic diagram of a charging coil set on the first substrate of a wireless charging device according to an embodiment of the present invention. As shown in Figure 4, the number of charging coils 13 set on the first substrate 11 is three, and the first substrate 11 has a wiring area covered by the charging coil 13 (corresponding to the annular area of the three charging coils 13) and a non-wiring area not covered by the charging coil 13 (corresponding to the area of the three charging coils 13 that do not overlap each other).

Please refer to FIG. 5 in conjunction with FIG. 1 and FIG. 4 . FIG. 5 is a schematic diagram of a comb filter disposed on the second substrate of a wireless charging device according to an embodiment of the present invention. As shown in FIG. 5 , the comb filter 14 includes a comb structure 141 and a grounding structure 142. The projection area of the comb structure 141 in the stacking direction D at least partially overlaps the three charging coils 13. The grounding structure 142 is connected to the comb structure 141 and the metal connector 17 and is located at the periphery of the comb structure 141. The comb structure 141 includes a plurality of wires. The three thermistors 15 are respectively disposed on three of the wires of the comb structure 141 and are preferably disposed above the non-wiring area of the first substrate 11, that is, each of them corresponds to a charging coil 13. The controller 16 is connected to the thermistor 15 through a connecting portion 1411 of the comb structure 141 to read the resistance change of each thermistor 15, and obtain the current temperature of multiple (three) local areas of the second substrate 12 accordingly. When the controller 16 determines that the current temperature of any local area of the second substrate 12 is greater than a preset temperature, it means that the temperature of the mobile phone waiting for charging device is too high, and the controller 16 can control the charging coil to reduce the charging power or stop charging.

The line width and line spacing of the comb structure 141 may be related to the frequency of the wireless charging signal emitted by the charging coil 13. Please refer to FIG. 6, which is a partial enlarged view of area A of FIG. 5. As shown in FIG. 6, the wire of the comb structure 141 has a line width d1, and there is a line spacing d2 between adjacent wires. The line width d1 and line spacing d2 of the comb structure 141 may be related to the frequency of the wireless charging signal emitted by the charging coil 13. For example, the line width d1 may be 13 mm, and the line spacing d2 may be 17 mm. Please refer to Table 1, which shows the filtering effect of different line widths d1 and line spacings d2 of the comb structure 141 corresponding to signals of different frequencies.

As shown in Table 1, the first column shows the case where the comb filter of the present invention is not used (NA). In this case, the worst filtering effect is achieved for charging signals of various frequencies. The second column shows the case where the line width of the comb filter 14 is 13 mm and the line spacing is 17 mm. In this case, the best filtering effect is achieved for charging signals with a frequency of 1.34 MHz. The third column shows the case where the comb filter 14 has a line width of 13 mm and a line spacing of 17 mm. When the line width is 10 mm and the line spacing is 20 mm, the overall filtering effect is slightly lower than when the line width/line spacing is 13/17 mm, but filtering can still be performed effectively; the fourth row is the comb filter 14 with a line width of 10 mm and a line spacing of 15 mm. In this case, it has the best filtering effect for charging signals with frequencies of 0.85 and 1.14 MHz. Accordingly, the comb filter of this case can design and adjust the line width and line spacing of the comb structure according to the frequency range of the wireless charging signal in actual application to optimize the filtering effect. In addition, the above test safety standard is CISPR 25 Class 3.

Please refer to FIG. 7 in conjunction with FIG. 4 and FIG. 5 , which shows the corresponding position relationship between thermistors and charging coils of a wireless charging device according to an embodiment of the present invention. As shown in FIG. 7 , the projection of the three charging coils 13 located on the first substrate 11 on the first surface 121 of the second substrate 12 in the aforementioned stacking direction is completely covered by the comb structure 141 and the grounding structure 142 of the comb filter 14, so that the comb filter 14 can better filter the charging coils 13. Furthermore, the three thermistors 15 are arranged to be located above the aforementioned non-wiring area, and are respectively located above a central area of the first substrate surrounded by each of the three charging coils. It should be noted that the thermistor 15 in this figure is also connected to the controller 16 through a part of the comb structure as shown in Figure 5, and its repeated description and drawing are omitted here. Through this configuration, no matter whether the device to be charged (such as a mobile phone) is placed above or below the second substrate 12, the charging coil at the corresponding position can charge it wirelessly. When the device to be charged overheats, the thermistor 15 at the corresponding position can also sense its temperature change more accurately, and allow the controller to obtain the resistance value change associated with the temperature change.

Please refer to FIG8 , which is a plan view of the second substrate of the wireless charging device according to another embodiment of the present invention. In this example, the wireless charging device may further include a near field communication antenna 19, which is disposed on the second surface 122 of the second substrate 12 opposite to the comb filter and connected to the controller 16. As shown in FIG8 , the near field communication coil 19 is located on the periphery of the three charging coils 13 along the projection of the first substrate below, that is, the projection area of the near field communication antenna 19 on the first substrate along the aforementioned stacking direction does not overlap the three charging coils 13, so that the wireless charging signal of the charging coil 13 is less likely to affect the operation of the near field communication coil 19. Specifically, the near field communication coil 19 of this example has a two-turn pattern structure, wherein the line width is 50 mm and the line spacing is 6 mm. Furthermore, after the NFC coil 19 is controlled by impedance matching at 13.56 MHz, it can read cards with a distance of more than 5 cm for various NFC chips, and allow the controller 16 to obtain the card reading signal.

When the controller 16 obtains the card reading signal, it can be determined that the device to be charged (such as a mobile phone) may be placed in the vicinity of other cards with near-field communication chips during the charging process. Therefore, the controller 16 can control the charging coil 13 to stop charging to prevent the charging signal from damaging the near-field communication chip on the card. It should be noted that the present embodiment may include the application of the aforementioned embodiment, that is, the controller 16 may determine whether the current temperature of the second substrate 12 is greater than a preset temperature through the thermistor, and control the charging coil to reduce the charging power or stop charging when the temperature is too high to prevent the device to be charged from overheating and being damaged; on the other hand, the card reading signal may be obtained through the near field communication coil 19, and when the card reading signal is obtained, the charging coil 13 may be controlled to stop charging to prevent the charging signal from damaging the near field communication chip on the card.

Please refer to FIG. 9, which is a schematic diagram of the structure of a wireless charging device according to another embodiment of the present invention. As shown in FIG. 9, the wireless charging device 1 of this embodiment includes not only a first substrate 11, a second substrate 12, at least one charging coil 13, a comb filter 14, a thermistor (not shown) and a controller (not shown), but also an insulating layer 18 disposed between the at least one charging coil 13 and the comb filter 14. Through the provision of the insulating layer 18, the second substrate 12 and the comb filter 14 can be supported on the charging coil 13, and the comb filter 14 and the charging coil 13 can be electrically isolated.

With the above structure, the wireless charging device disclosed in this case can reduce the electromagnetic interference problem that the charging coil may generate to the surrounding environment when charging by setting a substrate with a comb filter above the charging coil. The wireless charging device of this case can sense whether the mobile phone is overheated when charging by setting a thermistor in the comb filter, and because the thermistor is connected to the controller that receives the signal through a part of the comb filter, the overall circuit connection of the wireless charging device is more concise. In addition, the wireless charging device of this case can detect whether there are other cards with near-field communication chips approaching the charging range of the wireless charging coil by setting a near-field communication coil on the side of the second substrate opposite to the comb filter, thereby preventing the charging signal from damaging the near-field communication chip on the card during the charging process.

In one embodiment of the present invention, the wireless charging device of the present invention can be applied to a vehicle-mounted device, such as a self-driving car, an electric car, or a semi-autonomous car, etc.

Although the present invention is disclosed as above by the aforementioned embodiments, it is not intended to limit the present invention. Any changes and modifications made within the spirit and scope of the present invention are within the scope of patent protection of the present invention. Please refer to the attached patent application for the scope of protection defined by the present invention.

1: Wireless charging device

11: First substrate

12: Second substrate

121: First page

122: Second side

123:Through hole

13: Charging coil

14: Comb filter

15: Thermistor

16: Controller

17:Metal connectors

D: Stacking direction

Claims (10)

A wireless charging device comprises: a first substrate; at least one charging coil disposed on the first substrate; a second substrate disposed above the at least one charging coil; a comb filter disposed on the second substrate, and the projection area in the stacking direction at least partially overlaps the at least one charging coil; at least one thermistor disposed on the comb filter for reading the current temperature of the second substrate; and a controller connected to the at least one charging coil and connected to the at least one thermistor through a portion of the comb filter. In the wireless charging device as described in claim 1, the comb filter comprises: a comb structure, the projection area of which in the stacking direction at least partially overlaps with the at least one charging coil; and a grounding structure connected to the comb structure and located at the periphery of the comb structure. A wireless charging device as described in claim 2, wherein the line width and line spacing of the comb structure are related to the frequency of the wireless charging signal emitted by the at least one charging coil. A wireless charging device as described in claim 2, wherein the second substrate has a plurality of through holes, and the wireless charging device further comprises: A plurality of metal connectors disposed in the through holes, connected to the grounding structure, and used for grounding. A wireless charging device as described in claim 1, wherein the comb filter is disposed on a side of the second substrate facing the at least one charging coil, the second substrate has a plurality of through holes, and the wireless charging device further comprises: A plurality of metal connectors disposed in the through holes and separating the second substrate and the at least one charging coil from each other. The wireless charging device as described in claim 1, wherein the comb filter is disposed on a side of the second substrate facing the at least one charging coil, and the wireless charging device further comprises: an insulating layer disposed between the at least one charging coil and the comb filter. A wireless charging device as described in claim 1, wherein the first substrate has a wiring area covered by the at least one charging coil and a non-wiring area not covered by the at least one charging coil, and the at least one thermistor is disposed above the non-wiring area. A wireless charging device as described in claim 1, wherein the number of the at least one thermistor is the same as the number of the at least one charging coil, and the at least one thermistor is arranged to be located above a central area surrounded by each of the at least one charging coil. The wireless charging device as described in claim 1 further comprises: A near field communication antenna, disposed on the side of the second substrate opposite to the comb filter and connected to the controller. A wireless charging device as described in claim 9, wherein a projection area of the near field communication antenna on the first substrate along the stacking direction does not overlap with the at least one charging coil.

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