Temperature sensors and applications in wireless charging

Abstract

Some embodiments of this disclosure relate to systems and methods for detecting temperature using a bimetallic thermocouple embedded in a printed circuit board (PCB). In some embodiments, the PCB includes a thermocouple embedded in the PCB. The thermocouple includes a first metal trace and a second metal trace. The thermocouple is configured to generate a voltage that indicates the temperature associated with the PCB. In some embodiments, the thermocouple or thermistor is utilized by a wireless charging pad to detect the temperature.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims priority to U.S. Provisional Patent Application No. 63 / 487,554, filed on February 28, 2023, entitled "Temperature Sensing in Wireless Charging", the entire technical disclosure of which is incorporated herein by reference for all purposes.

[0002] This disclosure relates to systems and methods for temperature sensing. More particularly, embodiments of the present disclosure relate to temperature sensors and circuits or components for sensing temperature.

Background Art

[0003] To detect one or more temperatures associated with a device or system, a wide variety of temperature sensors can be utilized by the device or system. For example, bimetallic thermocouples that generate a voltage signal between the ends of two metal traces are used in various devices for temperature detection. Temperature sensing can be implemented in various applications.

Summary of the Invention

[0004] The systems, methods, and devices of the present disclosure each have several innovative embodiments, and no single one of them alone bears all of the desirable attributes disclosed herein. Details of one or more implementations of the subject matter described herein are set forth in the accompanying drawings and the following description.

[0005] In some aspects, the technology described herein relates to a printed circuit board (PCB) that includes a thermocouple embedded in the PCB and including a first metal trace and a second metal trace, the thermocouple being configured to generate a voltage indicative of temperature.

[0006] In some embodiments, the technology described herein relates to a PCB in which a first metal trace contains copper and a second metal trace contains constantan.

[0007] In some embodiments, the technology described herein relates to a PCB further comprising a dielectric layer disposed between a first metal trace and a second metal trace.

[0008] In some embodiments, the technology described herein relates to a PCB further comprising a second dielectric layer and a third dielectric layer, wherein a first metal trace and a second metal trace are disposed between the second dielectric layer and the third dielectric layer.

[0009] In some embodiments, the technology described herein relates to a PCB, further comprising a second thermocouple embedded in the PCB, the second thermocouple being configured to produce a second voltage indicating a second temperature, and the temperature and the second temperature being associated with different locations.

[0010] In some embodiments, the technology described herein relates to a PCB in which a first metal trace of a second thermocouple has an end short-circuited to the first metal trace of the thermocouple, and a second metal trace of the second thermocouple has an end short-circuited to the second metal trace of the thermocouple.

[0011] In some embodiments, the technology described herein relates to a PCB in which a thermocouple and a second thermocouple are arranged in parallel.

[0012] In some embodiments, the technology described herein relates to a PCB, wherein a thermocouple and a second thermocouple are connected to the same hot junction.

[0013] In some embodiments, the technology described herein relates to a PCB further comprising a surface layer disposed on a thermocouple, wherein the surface layer comprises a coil configured to generate an electromagnetic field for wireless charging.

[0014] In some embodiments, the technology described herein relates to a PCB, further comprising 100 additional embedded thermocouples.

[0015] In some embodiments, the technology described herein relates to a wireless charging pad including a PCB.

[0016] In some embodiments, the technology described herein relates to a PCB assembly comprising a PCB and a processing circuit, wherein the processing circuit is configured to determine temperature based on voltage.

[0017] In some embodiments, the technology described herein relates to a charging pad comprising: a coil configured to generate an electromagnetic field for wireless charging; one or more sensors configured to generate one or more detection signals for thermally detecting an object placed on the coil; and a processing circuit communicating with one or more sensors, configured to control the operation of the charging pad based on at least one or more detection signals.

[0018] In some embodiments, the technology described herein relates to a charging pad configured to thermally detect an object while a coil wirelessly transmits power to a second coil in a vehicle pad of a vehicle.

[0019] In some embodiments, the technology described herein relates to a charging pad in which one or more sensors, thermocouples, embedded in a printed circuit board, are included.

[0020] In some embodiments, the technology described herein relates to a charging pad wherein the thermocouple is a T-type thermocouple.

[0021] In some embodiments, the technology described herein relates to a charging pad in which one or more sensors are surface-mount thermocouples.

[0022] In some aspects, the technology described herein relates to a charging pad that includes 100 thermistors in one or more sensors.

[0023] In some aspects, the technology described herein relates to a charging pad configured to control the operation of the charging pad based on at least one detection signal by determining, based on one or more detection signals, that an object is placed on a coil and, in response to the determination that the object is placed on the coil, stopping the generation of an electromagnetic field in the coil.

[0024] In some aspects, the technology described herein relates to a charging pad in which the maximum dimension of an object is less than 50 millimeters.

[0025] In some aspects, the technology described herein relates to a charging pad configured to be connected to an external power source and sized to be placed under a vehicle.

[0026] In some aspects, the technology described herein relates to a method of wireless charging using thermal object detection, including thermally detecting an object placed between a wireless charging pad and a vehicle pad while wirelessly transmitting power between the wireless charging pad and the vehicle pad, and stopping the wireless transmission of power in response to the thermal detection.

[0027] In some aspects, the technology described herein relates to a method in which an object is placed on the surface of a wireless charging pad.

[0028] In some aspects, the technology described herein relates to a method in which an object has a maximum dimension of 50 millimeters or less.

[0029] In some aspects, the technology described herein relates to a method, a method in which an object includes a metal.

[0030] In some aspects, the technology described herein relates to a method, a method in which thermal detection is performed using a thermocouple embedded in a printed circuit board.

Brief Description of the Drawings

[0031] Throughout the drawings, reference numbers are repeatedly used to indicate corresponding between the elements being referenced. The drawings are provided to illustrate examples of the subject matter described herein and are not intended to limit its scope.

[0032] Embodiments of the present disclosure are described with reference to the accompanying drawings, in which like reference numerals refer to like elements.

[0033] [Figure 1] It is a diagram showing an exemplary bimetal thermocouple.

[0034] [Figure 2] It is a diagram showing an exemplary printed circuit board (PCB) in which a bimetal thermocouple is embedded according to some embodiments of the present disclosure.

[0035] [Figure 3A] It is a diagram showing an exemplary connection between bimetal thermocouples according to an embodiment of the present disclosure.

[0036] [Figure 3B] It is a diagram showing an exemplary pattern of a bimetal thermocouple according to various aspects of the present disclosure.

[0037] [Figure 4A] It is a diagram of a wireless charging system including a wireless charger in which a temperature sensor can be arranged according to various aspects of the present disclosure.

[0038] [Figure 4B]This figure shows an example of a wireless charger and vehicle according to an embodiment of the present disclosure.

[0039] [Figure 4C] This is a top view of an example of a wireless charger and vehicle according to an embodiment of the present disclosure.

[0040] [Figure 4D] Block diagram showing an example of a wireless charger and vehicle according to an embodiment of the present disclosure.

[0041] [Figure 5A] This is a schematic diagram showing an exemplary wireless charger according to an embodiment of the present disclosure.

[0042] [Figure 5B] This figure shows an exemplary component integrated into the wireless charger shown in Figure 5A, according to an embodiment of the present disclosure.

[0043] [Figure 5C] This figure shows an exemplary temperature sensor integrated into the wireless charger shown in Figure 5A, according to some embodiments of the present disclosure.

[0044] [Figure 5D] This figure shows an exemplary representation of an object on the wireless charger of Figure 5A that can be detected according to the embodiments of the present disclosure. [Modes for carrying out the invention]

[0045] The following detailed descriptions of several embodiments present various descriptions of a particular embodiment. However, the technological innovations described herein can be embodied in numerous different ways, for example, as defined and encompassed by the claims. In this description, similar reference numbers and / or terms refer to drawings in which identical or functionally similar elements may be shown. It will be understood that the elements shown in the drawings are not necessarily drawn to scale. Furthermore, it will be understood that some embodiments may include more elements and / or subsets of elements shown in the drawings than those shown. Furthermore, some embodiments may incorporate any suitable combination of features from two or more drawings. Headings are provided for convenience only and do not affect the claims or their meaning.

[0046] In general terms, one or more aspects of the present disclosure relate to systems and methods for sensing temperature using one or more bimetallic thermocouples embedded in a printed circuit board (PCB). More specifically, some embodiments of the present disclosure relate to one or more bimetallic thermocouples, each bimetallic thermocouple comprising two metal traces located within one or more metal layers of the PCB. Embedding the bimetallic thermocouples in the metal layers of the PCB, instead of placing one or more bimetallic thermocouples on the surface of the PCB, allows for advantageous saving of surface area (e.g., top surface) of the PCB, increased integration of the bimetallic thermocouples and associated metal traces with the PCB, reduced manufacturing costs and assembly complexity, or any suitable combination thereof.

[0047] In some embodiments, a bimetallic thermocouple embedded in a PCB (e.g., one or more metal layers of the PCB) may be made from a specific combination of metals. This makes it possible to balance the trade-off between the temperature sensing performance of the bimetallic thermocouple and the manufacturing cost of the PCB. For example, a bimetallic thermocouple embedded in a PCB may include one metal trace made of copper and the other metal trace made of constantan.

[0048] In some embodiments, multiple bimetallic thermocouples and / or other suitable thermal sensors can be utilized by the wireless charging pad to detect one or more temperatures associated with the wireless charging pad (e.g., the temperature at a specific location on the wireless charging pad, or the average temperature over a larger or entire area of ​​the wireless charging pad). To mitigate the complexity of signal processing and reduce the number of temperature measurements, in some embodiments, several traces between multiple bimetallic thermocouples may be short-circuited so that the average temperature associated with various locations on the PCB can be determined in a single detection signal measurement. In some embodiments, bimetallic thermocouples and / or other suitable types of thermal sensors (e.g., thermistors) (e.g., embedded in or mounted on the surface of the PCB) can be utilized by the wireless charging pad to thermally detect foreign objects (e.g., metallic objects) between one wireless charging pad and another.

[0049] A wide variety of temperature sensors can be used by a device or system to detect one or more temperatures associated with that device or system. For example, bimetallic thermocouples, which generate a voltage signal across the ends of two metal traces, are used in various devices to detect temperature. Typically, the metal traces of a bimetallic thermocouple are routed on or above a substrate (e.g., a coil substrate, PCB) to detect temperature. Routed bimetallic thermocouple metal traces onto a substrate can occupy surface area of ​​the substrate that would otherwise be available for other purposes (e.g., mounting and / or connecting other circuits in the system). Furthermore, the limited surface area of ​​the substrate with thermocouple traces on the PCB surface can complicate the design and increase costs associated with manufacturing the substrate. Therefore, it may be desirable to embed the bimetallic thermocouple in one or more layers of the substrate.

[0050] Embedding or integrating bimetallic thermocouples into one or more layers of a substrate can be challenging. For example, it may be impossible to wire a specific type of metal within a PCB layer while meeting the technical specifications for both thermocouple sensing performance and PCB manufacturing cost. More specifically, some thermocouple types may offer desirable temperature sensing performance (e.g., sensitivity, accuracy) but may be too costly to embed in the metal layers of a PCB, while other thermocouple types can be more economically embedded in the metal layers of a PCB but may have inferior temperature sensing performance.

[0051] To address at least some of the technical challenges described above, some aspects of the technology of this disclosure relate to a PCB in which one or more bimetallic thermocouples are embedded in one or more metal layers of the PCB for sensing temperatures associated with the PCB. The one or more bimetallic thermocouples may be T-type thermocouples in order to achieve accurate temperature sensing based on bimetallic thermocouples while maintaining the manufacturing parameters of the PCB. More specifically, the one or more bimetallic thermocouples embedded in the PCB may utilize copper as one metal trace and constantan as the other metal trace.

[0052] In some embodiments, the PCB may include a first bimetallic thermocouple located within one or more metal layers of the PCB. The first bimetallic thermocouple may include a copper trace and a constantan trace. The first bimetallic thermocouple may be configured to detect the temperature of a location (e.g., the upper right corner) and / or a region of the PCB. For example, one end of the copper trace of the first bimetallic thermocouple may be short-circuited to one end of the constantan trace of the first bimetallic thermocouple. To determine the temperature at the aforementioned location on the PCB, the voltage difference between the other end of the copper trace and the other end of the constantan trace of the first bimetallic thermocouple may be measured by a processing circuit.

[0053] In some embodiments, the PCB may include a second bimetallic thermocouple located within one or more metal layers of the PCB. The second bimetallic thermocouple may include a copper trace and a constantan trace, with one end of the copper trace short-circuited to the other end of the constantan trace. The second bimetallic thermocouple may be configured to detect the temperature at another location on the PCB (e.g., the lower left corner).

[0054] In some embodiments, the copper traces of the first bimetallic thermocouple and the second bimetallic thermocouple can be short-circuited to reduce the complexity of signal processing and the number of temperature measurements, and the constantant traces of the first bimetallic thermocouple and the second bimetallic thermocouple can also be short-circuited. Therefore, the average temperature of the temperature detected by the first bimetallic thermocouple and the temperature detected by the second bimetallic thermocouple can be determined.

[0055] More specifically, the copper traces of the first bimetallic thermocouple and the copper trace of the second bimetallic thermocouple can be connected to the input terminals of the processing circuit, and the constantant trace of the first bimetallic thermocouple and the constantant trace of the second bimetallic thermocouple can be connected to other input terminals of the processing circuit. Thus, the voltage difference measured by the processing circuit may be a weighted average (based on the relative resistance between the first and second bimetallic thermocouples) of the voltage differences between the copper traces and constantant traces of the first and second bimetallic thermocouples. Thus, the processing circuit can measure the average temperature associated with the first and second bimetallic thermocouples in a single electrical signal measurement.

[0056] Thermal object detection may be desirable in wireless charging applications, such as wireless charging applications related to charging vehicle battery packs. Heated objects on the surface of a wireless charging pad can be detected by thermal object detection. This allows for the detection of, for example, a metallic object placed on the wireless charging pad that is heated during wireless charging. In response to the detection of a metallic object, wireless charging may be stopped. This prevents metal objects in close contact with the surface of the wireless charging pad from igniting during wireless charging.

[0057] In some embodiments, a bimetallic thermocouple embedded in the PCB can be used by the wireless charging pad to thermally detect foreign objects between one wireless charging pad and another. In addition to using a bimetallic thermocouple embedded in the PCB, other types of bimetallic thermocouples (e.g., surface-mount bimetallic thermocouples) and / or thermal sensors (e.g., thermistors) can be used by the wireless charging pad to thermally detect foreign objects.

[0058] For example, in some embodiments, a wireless charging pad may include a first coil, one or more temperature sensors (e.g., a bimetallic thermocouple embedded in a PCB, a surface-mount bimetallic thermocouple, a thermistor), and a processing circuit or processor that communicates with one or more temperature sensors. The wireless charging pad may be used for wireless power transmission between the first coil and the second coil. The first coil may be configured to generate an electromagnetic field for wireless charging. One or more temperature sensors may be configured to generate one or more detection signals for thermally detecting an object placed between the first coil and the second coil. The processing circuit may be configured to control the operation of the first coil based on at least one or more detection signals. For example, the thermal object detection may detect a metallic object. When a metallic object is detected, the processing circuit may, for example, stop wireless power transmission to the wireless charging pad. This can prevent the metallic object from overheating and / or igniting.

[0059] While the aspects of this disclosure are described with respect to exemplary components, interactions, and routines, those skilled in the art will understand that one or more aspects of this disclosure may be implemented according to various environments, system architectures, customer computing device architectures, etc. Similarly, references to specific devices, such as wireless charging pads, should be considered general references and are not intended to provide additional meaning or configurations for individual wireless charging pads. Furthermore, examples and exemplary configurations are not intended to be limiting and should not be construed as limiting the scope of this disclosure. Moreover, examples are intended to be illustrative in nature and should not be construed as limiting.

[0060] Overview of Bimetallic Thermocouples Figure 1 shows an exemplary bimetallic thermocouple 100. The bimetallic thermocouple 100 includes a first metal trace 102 and a second metal trace 104. The first metal trace 102 and the second metal trace 104 consist of different types of metals and / or alloys having different Seebeck coefficients (e.g., iron, chromel, alumel, platinum, rhodium, copper, constantan, etc.). The types of metals for forming the first metal trace 102 and the second metal trace 104 may be selected based on the desired temperature sensing range (e.g., chromel and alumel can be selected to sense a temperature range of -270°C to 1370°C) and / or application.

[0061] As shown in Figure 1, one end of the first metal trace 102 and one end of the second metal trace 104 are short-circuited to form a contact 106 (e.g., a "hot" contact). The other end 108 of the first metal trace 102 and the other end 110 of the second metal trace 104 are not electrically connected and may be kept at approximately the same temperature and may be considered a "hot" contact. If a temperature difference appears between the "hot" contact and the "cold" contact (e.g., between the other end 108 of the first metal trace 102 and the other end 110 of the second metal trace 104) due to different temperature sensing characteristics, a voltage difference can be measured at the "cold" contact. By measuring and processing the voltage difference, the temperature associated with the bimetallic thermocouple 100 (e.g., the temperature of the contact 106) can be determined. The thermocouple output voltage across ends 108 and 110 of the metal traces may act as a function of the hot junction temperature. Based on an equation that correlates the hot junction temperature to the thermocouple output voltage of a specific material in the metal trace of a thermocouple, the hot junction temperature can be determined for a measured thermocouple output voltage.

[0062] PCB-embedded bimetallic thermocouple Figure 2 shows an exemplary PCB 200 with embedded bimetallic thermocouples according to several embodiments of the present disclosure. The PCB 200 comprises bimetallic thermocouples 202, 204, 206, 208, 212, 214, 216, and 218. As shown in Figure 2, bimetallic thermocouples 202, 204, 206, and 208 are located within the bent portion of the PCB 200, while bimetallic thermocouples 212, 214, 216, and 218 are located within the rigid portion of the PCB 200 (made of a material that is either more rigid or less flexible than the bent portion).

[0063] In some embodiments, each of the bimetallic thermocouples 202, 204, 206, 208, 212, 214, 216, and 218 may be a T-type thermocouple (including, for example, copper traces and constantan traces). Advantageously, compared to other types of thermocouples, T-type thermocouples may be easier to print in the PCB manufacturing process. Therefore, by using T-type thermocouples, the cost and / or complexity of embedding thermocouples in the PCB can be reduced.

[0064] The bimetallic thermocouple 202 may include a copper trace and a constantan trace. Constantan is a copper-nickel alloy that may be 55% copper and 45% nickel. Using a thermocouple with copper and constantan traces, temperatures in the range of -200°C to 400°C can be detected. Such a thermocouple can have an electromotive force over a temperature range of -6.258 millivolts (mV) to 20.872 mV. Furthermore, such a thermocouple can have a Seebeck coefficient of 38.75 μV / °C at 0°C. Figure 2 may be illustrated with reference to a T-type thermocouple, but any suitable principles and advantages described with reference to Figure 2 and / or any other embodiments can be applied to any suitable type of thermocouple.

[0065] As shown in Figure 2, the copper trace and constantan trace at one end of the bimetallic thermocouple 202 are short-circuited to form contact 202-1 (e.g., a "hot" contact). The processing circuit 260 can determine the temperature of contact 202-1 by measuring and processing the voltage difference at the other end of the bimetallic thermocouple 202. The copper trace and constantan trace at one end of the bimetallic thermocouples 204, 206, and 208 can also be short-circuited to form contacts 204-1, 206-1, and 208-1 (e.g., "hot" contacts), respectively.

[0066] In some embodiments, the processing circuit 260 may include a reference resistive thermal device (RTD) 262, an amplifier and filter module 264, and a power supply circuit 266. The reference RTD 262 can vary its resistance depending on the temperature to provide a reference voltage to the processing circuit 260. The amplifier and filter module 264 can amplify the voltage signals received from each of the bimetallic thermocouples embedded in the PCB 200. The power supply circuit 266 can generate a power supply voltage for the processing circuit 260. For example, the power supply circuit 266 can generate a 3V rail for the processing circuit 260. The processing circuit 260 may include any suitable circuitry for processing the output signals from the thermocouples and / or for controlling the operation of wireless charging (e.g., stopping wireless charging) in response to object detection.

[0067] As shown in Figure 2, the PCB 200 has layers 232 (e.g., top layer), 234 (e.g., dielectric layer), 236 (e.g., copper layer), 238 (e.g., dielectric layer), 240 (e.g., constantan layer), 242 (e.g., dielectric layer), and 244 (e.g., bottom layer). The copper traces of bimetallic thermocouples 202, 204, 206, 208, 212, 214, 216, and 218 may be in layer 236, and the constantan traces of bimetallic thermocouples 202, 204, 206, 208, 212, 214, 216, and 218 may be in layer 240. The traces of bimetallic thermocouples 202, 204, 206, 208, 212, 214, 216, and 218 may be routed to any other suitable layered configuration associated with PCB 200 and / or other suitable PCBs (e.g., copper traces routed in layer 244 and constantan traces routed in layer 240; copper traces routed in layer 232 and constantan traces routed in layer 236). Figure 2 shows that bimetallic thermocouples 202, 204, 206, 208, 212, 214, 216, and 218 are substantially parallel, but it should be noted that bimetallic thermocouples embedded in PCB 200 may correspond to any other suitable pattern, including various geometric patterns (e.g., radial patterns, or any other regular or irregular patterns).

[0068] In some embodiments, for each of the bimetallic thermocouples 202, 204, 206, 208, 212, 214, 216, and 218, the processing circuit 260 can measure the voltage and determine the temperature. In this way, the processing circuit 260 can perform eight voltage measurements to determine eight temperature values. In some other embodiments (for example, as shown in Figure 3A), the copper traces of some bimetallic thermocouples 202, 204, 206, 208, 212, 214, 216, and 218 may be short-circuited, or the constantan traces of some bimetallic thermocouples 202, 204, 206, 208, 212, 214, 216, and 218 may be short-circuited, further details of which are described below with reference to Figure 3A.

[0069] Figure 3A shows exemplary connections between bimetallic thermocouples 202, 204, 206, and 208 embedded in PCB 200. As described above, the copper trace and constantan trace of bimetallic thermocouple 202 may be short-circuited to form contact 202-1. The copper trace and constantan trace of bimetallic thermocouple 204 may be short-circuited to form contact 204-1. The copper trace and constantan trace of bimetallic thermocouple 206 may be short-circuited to form contact 206-1. The copper trace and constantan trace of bimetallic thermocouple 208 may be short-circuited to form contact 208-1. Although bimetallic thermocouples 202, 204, 206, and 208 are shown substantially parallel, other geometric arrangements or patterns (e.g., radial patterns, tree-like patterns, etc.) may be used.

[0070] As shown in Figure 3A, the copper traces of bimetallic thermocouples 202, 204, 206, and 208 are short-circuited, and the constantan traces of bimetallic thermocouples 202, 204, 206, and 208 are also short-circuited. The copper traces of bimetallic thermocouples 202, 204, 206, and 208 may be connected to input terminal 364 of the processing circuit 260, and the constantan traces of bimetallic thermocouples 202, 204, 206, and 208 may be connected to input terminal 362 of the processing circuit 260. Since the copper traces and constantan traces are short-circuited, the voltage difference between input terminal 362 and input terminal 364 can be a weighted average of the voltage differences between the copper traces and constantan traces of bimetallic thermocouples 202, 204, 206, and 208. The weighted average may be based on the relative resistance between bimetallic thermocouples 202, 204, 206, and 208, which may be related to the length and / or thickness of the traces of the bimetallic thermocouples 202, 204, 206, and 208. In this way, the processing circuit 260 can measure the average temperature associated with bimetallic thermocouples 202, 204, 206, and 208 in a single measurement.

[0071] For example, let's assume that, with the copper traces (or constantan traces) not short-circuited to each other, the voltage difference between the copper trace and the constantan trace of bimetallic thermocouple 202 is V1, the voltage difference between the copper trace and the constantan trace of bimetallic thermocouple 204 is V2, the voltage difference between the copper trace and the constantan trace of bimetallic thermocouple 206 is V3, and the voltage difference between the copper trace and the constantan trace of bimetallic thermocouple 208 is V4. By short-circuiting the copper traces of bimetallic thermocouples 202, 204, 206, and 208 with the constantan traces of bimetallic thermocouples 202, 204, 206, and 208, the voltage difference between input terminal 362 and input terminal 364 can be made the average of V1, V2, V3, and V4, assuming equal weighting during averaging. Therefore, the processing circuit 260 can perform a single measurement and process the average voltage difference to determine the average temperature, rather than measuring four voltage differences and processing them individually to determine four temperatures. Advantageously, by short-circuiting both the first and second metal traces of the thermocouple, the processing circuit 260 can determine the average temperature over a wide area related to the PCB 200 with fewer voltage measurements and reduced signal processing complexity.

[0072] Figure 3B shows an exemplary wiring pattern 350 of bimetallic thermocouples embedded in a PCB according to several embodiments of the present disclosure. As shown in Figure 3B, the wiring pattern 350 includes bimetallic thermocouples 320-1, 320-2, 320-3, and 320-4. The bimetallic thermocouples 320 include a radial pattern in which each of the bimetallic thermocouples 320-1, 320-2, 320-3, 320-4, etc., is wired so as to spread outward from a central region. A heat-generating object 330 can be detected on the wiring pattern 350 in Figure 3B. In some embodiments, some of the bimetallic thermocouples 320-1, 320-2, 320-3, 320-4, etc., may share one or more "hot" junctions. For example, bimetallic thermocouples 320-4 and 320-3 share a "hot" junction 340. It should be noted that in other embodiments of this disclosure, other types of connections between bimetallic thermocouples (e.g., tree-like connections) may also be used to embed the bimetallic thermocouples into the PCB.

[0073] Thermocouples embedded in PCBs can be used in a variety of applications. Exemplary applications of PCB-embedded thermocouples include, but are not limited to, temperature sensing related to wireless charging (e.g., embedded in a PCB containing coils for wireless charging) or integrated magnetic circuits under power field-effect transistors and / or other integrated circuits for battery temperature measurement. For battery temperature measurement, embedded thermocouples can be implemented as a flexible PCB for rapid and accurate temperature measurement. Embedded thermocouple substrates can include more measurement points at relatively low cost and design effort. Parallel thermocouples, according to any suitable principle and advantages disclosed herein, can be implemented in applications where average measurements are desired instead of individual measurements, and / or for batch measurements over a wider area.

[0074] Thermal detection for wireless charging According to one or more aspects of this disclosure, temperature sensors such as a bimetallic thermocouple embedded in the PCB 200 described above, one or more other types of bimetallic thermocouples (e.g., surface-mount bimetallic thermocouples), and / or one or more other suitable thermal sensors (e.g., thermistors) may be integrated into a wireless charging pad (e.g., grounding pad) of a wireless charging system for sensing temperature, which may be useful for a variety of applications. Using the temperature sensors, one or more objects placed between the coils of the wireless charging pad can be detected. In some embodiments, the temperature sensors are configured to monitor the surface temperature of the wireless charging pad. For example, to measure the surface temperature of the wireless charging pad, a PCB with embedded bimetallic thermocouples may be placed inside the wireless charging pad. As described above, the bimetallic thermocouple includes two metal strips or traces associated with different Seebeck coefficients. When the bimetallic thermocouple is exposed to different environmental inputs (e.g., temperature changes), electrons diffuse along the conductor, generating a voltage difference at the ends of the metal traces at the cold junction, which can indicate the detected temperature.

[0075] In some embodiments, a PCB printed with multiple bimetallic thermocouples may be included in the wireless charging pad to achieve temperature monitoring over a predetermined and / or defined surface area of ​​the wireless charging pad. In some embodiments, multiple bimetallic thermocouples with junction nodes may be positioned (e.g., beneath the surface of the wireless charging pad) to sense the temperature over the entire surface area of ​​the wireless charging pad or over a specific portion of the surface area.

[0076] In some embodiments, a bimetallic thermocouple may be included in the wireless charging pad to thermally detect one or more objects on or near the surface of the wireless charging pad in order to mitigate undesirable heat generation that could lead to ignition. Alternatively or additionally, one or more other types of sensors (e.g., magnetic field detection, inductance change detection, etc.) may be included in the wireless charging pad to detect objects placed between coils during wireless charging. For example, an object (e.g., a metallic object) can be detected by utilizing a passively detected mini-coil matrix on the wireless charging pad (e.g., a grounding pad) to monitor magnetic field disturbances caused by a metallic object during inductive charging. Another example is the detection of an object by utilizing an actively driven coil set on the grounding pad to monitor changes in coil characteristics (e.g., inductance changes) caused by an object during inductive charging. In another example relating to thermal object detection, for object detection and / or safety during operation, the wireless charging pad may utilize a thermal camera (e.g., integrated as part of the wireless charging pad or external to the wireless charging pad) to monitor temperature fluctuations or threshold temperatures in multiple areas of the wireless charging pad.

[0077] In some embodiments, a detection signal generated by a temperature sensor integrated with the wireless charging pad of the wireless charging system can be provided as temperature input data to a control circuit associated with the wireless charging system (e.g., a processor or any other suitable circuit). The temperature input data may be monitored to detect whether a thermal problem may be occurring in the wireless charging pad. The input may be processed, for example, by comparing it to a temperature threshold, a temperature fluctuation threshold, and / or other processing rules. Based on the processed temperature input (and optionally one or more other inputs), the control circuit may mitigate and / or identify a characterized thermal problem. Thermal problem mitigation techniques may include, but are not limited to, terminating the wireless charging process, changing one or more operating parameters, initiating a self-test procedure, initiating a thermal management procedure (e.g., a fire suppression procedure, a ventilation procedure), a warning process and / or an alarm process, a notification process, or any suitable combination thereof.

[0078] Overview of wireless charging Figures 4A to 4C illustrate examples of wireless charging systems 400 that can incorporate temperature sensors disclosed herein (e.g., bimetallic thermocouples embedded in a PCB, surface-mount bimetallic thermocouples, thermistors, etc.) for thermally detecting objects. More specifically, in some embodiments, a wireless charger 410 (also called a “wireless charging pad” or “grounding pad”) may be configured to charge a battery pack contained in a vehicle. For illustrative purposes, an electric vehicle 412 (shown in Figures 4B and 4C) coupled to the wireless charger 410 is described. However, the electric vehicle 412 is merely illustrative, and the wireless charger 410 may be configured to charge any battery-powered device, equipment, or platform that can receive wireless energy from the wireless charger. For example, any battery-powered electrical device, robot, boat, unmanned aerial vehicle, etc., having a component that receives energy generated from the wireless charger (e.g., a receiving coil connected to the battery pack for charging the battery pack), may be coupled to the wireless charger for charging a battery pack according to embodiments disclosed herein. The wireless charging disclosed herein can be applied to any suitable vehicle, including electric vehicles having a battery pack, as well as hybrid vehicles including an internal combustion engine and a battery pack.

[0079] Figure 4A is a diagram of a wireless charging system 400 including a wireless charger 410, such as an induction-based wireless charger, according to various embodiments of the present disclosure. The wireless charging system 400 may, exemplary, be adapted to commercial implementations such as parking lots, parking spaces, and charging booths. The wireless charging system 400 may also be adapted to private or other non-commercial implementations such as homes and garages. As an exemplary example, the wireless charger 410 may be configured to generate a variable electromagnetic field according to several embodiments.

[0080] As also shown in Figure 4A, the wireless charger 410, which may also be called a power transmission component, can correspond to a standalone component that can be mounted or positioned on the floor or other plane. In other embodiments, the wireless charger 410 may be integrated with or combined with one or more other devices or components.

[0081] The wireless charger 410 may be connected to one or more energy sources (e.g., power supplies), such as inputs from a utility company, real-time power supplies (e.g., solar or wind energy sources), energy storage cells, or any suitable combination thereof. The energy sources may be configured to provide input alternating current as described herein. In some examples, the wireless charger 410 may be connected to the power supply via a direct electrical connection 420, such as via an energy source 430 (e.g., a junction box) located on the wall.

[0082] As further shown in Figure 4A, the wireless charger 410 can be designed in a form factor that is permissible within a specified range determined by the form factor of the device intended to receive power from the wireless charger 410. For example, if the wireless charger 410 is intended to charge the battery pack of a vehicle 412 (shown in Figure 4B) including a receiving coil, the form factor of the wireless charger 410 will be such that the vehicle 412 can be positioned directly above the top surface of the wireless charger 410. The dimensions of the wireless charger 410, such as the height and / or width of the wireless charger 410, may be determined so that the gap between the top surface of the wireless charger and the bottom surface of the receiving device is ensured to be within a specific range. This range may also be a factor for improving and / or optimizing energy transfer between the wireless charger 410 and the receiving device, and may be defined by minimum and maximum distances that facilitate efficient energy transfer. The appropriate distance may vary depending on the specific application. In some embodiments, the wireless charger 410 may include one or more mechanisms for adjusting this distance (e.g., static adjustment and / or dynamic adjustment) or for changing the relative positioning between the wireless charger 410 and the receiving device to improve and / or optimize charging efficiency.

[0083] The wireless charger 410 may supply sufficient power to charge the battery pack of an electric vehicle and may also thermally detect an object. In some embodiments, the wireless charger 410 can be configured to charge the vehicle's battery pack, which may have a nominal voltage greater than 200 volts (e.g., a nominal voltage of about 350 or 355 volts) and a maximum voltage of 400 volts. In some embodiments, the wireless charger 410 can be configured to supply 800 volts of DC power. In some embodiments, the wireless charger 410 can supply voltages in the range of about 200 volts to 800 volts.

[0084] Figures 4B and 4C show an example of a wireless charger 410 and a vehicle 412 (e.g., an electric vehicle). Figure 4C shows a top view of the exemplary wireless charger 410 and vehicle 412 shown in Figure 4B. As shown in Figures 4B and 4C, the wireless charger 410 and vehicle 412 may be coupled to charge the battery pack of the vehicle 412 (not shown in Figures 4B and 4C). For example, the wireless charger 410 and receiving coil 404 of the vehicle 412 may be coupled at a threshold distance. The threshold distance may be defined as the range of distances at which efficient energy transfer can be provided between the wireless charger 410 and the receiving coil 404. For example, if efficient energy transfer is defined as 85% of the energy generated from the wireless charger 410, the threshold distance may correspond to a distance at which at least 85% of the energy transfer can be provided between the wireless charger 410 and the receiving coil 404 of the vehicle 412.

[0085] According to aspects of this disclosure, the wireless charger 410 may be configured to transmit energy via inductive coupling with a receiving coil 404, and as a result, the receiving coil 404 may be configured to receive energy from the wireless charger 410 via inductive coupling with the wireless charger 410. Exemplarily, the wireless charger 410 may include energy transmission components such as a transmitting coil. Such a transmitting coil may be an inductive coil. The wireless charger 410 may generally be referred to as a charging station, charging pad, or grounding pad. Such a transmitting coil may be configured to induce an electromagnetic field from power received from an energy source. The power may be supplied as an alternating current (AC) supplied from a power source such as a wall outlet or an external battery. This alternating current (AC) may pass through the transmitting coil. For example, such an AC current may flow into the transmitting coil, and as a result, charges may move through the transmitting coil. These movements in the transmitting coil may induce (or evoke) an electromagnetic field. Exemplary, a receiving coil 404 included in the vehicle 412 can receive an electromagnetic field by positioning the electromagnetic field within a certain distance from the wireless charger 410 (for example, by positioning the receiving coil 404 above the wireless charger 410 within a threshold distance). The threshold distance can be determined based on the strength of the generated electromagnetic field and a criterion defining the transfer energy ratio between the wireless charger 410 and the receiving coil 404. When the receiving coil 404 receives the electromagnetic field generated from the transmitting coil of the wireless charger 410, the strength of the electromagnetic field may vary, at least in part, due to changes or fluctuations in the AC amplitude. This change in the electromagnetic field may generate an alternating current in the receiving coil of the vehicle 412. The induced alternating current in the receiving coil 404 can then be converted to a direct current to charge the battery of the vehicle 412. For example, the induced alternating current may be transmitted through a rectifier, which can convert the induced alternating current to a direct current. The vehicle 412 can then be configured to use the direct current to charge its battery, supply operating power, or a combination of both.

[0086] Figure 4D shows a schematic block diagram of a wireless charging system including a wireless charger 410 wirelessly coupled to a vehicle 412. Wireless coupling can be achieved via an induction-based electromagnetic field induced by the transmitting coil of the wireless charger 410. The wireless charger 410 is further connected to one or more energy sources 430, such as a power wall, an external battery, or an external generator (e.g., solar energy). Although the wireless charger 410 is shown as being directly connected to the energy sources 430, at least a portion of the input AC current can also be provided by a wireless transmission method. In addition, in embodiments with multiple power sources, the environment may further include various switching components for selecting energy from the energy sources 430 or a combination of energy sources 430.

[0087] In some embodiments, as shown in Figure 4D, the wireless charger 410 and the vehicle 412 are coupled via an electromagnetic field generated from the transmitting coil of the wireless charger 410. According to aspects of the present disclosure, the wireless charger 410 may be configured to transmit energy via inductive coupling with a receiving coil 404 of the vehicle 412, and as a result, the receiving coil 404 is configured to receive energy from the wireless charger 410 via inductive coupling with the wireless charger 410. In some embodiments, an energy source 430 may supply input AC power to the wireless charger 410. This AC power includes an AC current that passes through the transmitting coil. An electromagnetic field may be induced by the transmitting coil due to the AC current. The induced electromagnetic field may be radiated outward (e.g., from the wireless charger 410) in a specific direction, such as vertically above the wireless charger (e.g., the transmitting coil is mounted inside the wireless charger facing vertically upward from the wireless charger 410). In some cases, the intensity of these vertically propagating electromagnetic fields may decrease in proportion to the distance from the top surface of the wireless charger 410. Therefore, the vehicle 412 (e.g., the receiving coil 404) can be positioned above the wireless charger 410 within a threshold distance that can provide the required electromagnetic field strength.

[0088] Examples of applications in wireless charging Figure 5A shows a block diagram of a wireless charger 410 that can implement embodiments of the present disclosure. The wireless charger 410 may include at least one coil (shown in Figures 5B-5C) for generating a magnetic field from an input current supplied from an energy source 430. As shown in Figure 5A, the input current can be provided by a direct electrical connection 420.

[0089] In some embodiments, the central portion 502 of the wireless charger 410 may include temperature sensors such as PCB-embedded bimetallic thermocouples, surface-mount bimetallic thermocouples, thermistors, or any suitable combination thereof. More specifically, multiple bimetallic thermocouples and / or thermistors may be placed beneath the surface of the central portion 502 to detect temperatures associated with various locations on the central portion 502 of the wireless charger 410. For example, multiple bimetallic thermocouples and / or thermistors may detect temperatures, enabling the wireless charger 410 to thermally detect heated objects on the central portion 502.

[0090] In some embodiments, the wireless charger 410 may also include various sensor components 504 (e.g., radar sensors) for various applications. For example, sensor components 504A, 504B, 504C, and 504D can be configured for various functions such as object detection, vehicle detection 412, distance measurement to vehicle 412, environmental sensing (using, for example, temperature sensors, humidity sensors, etc.), and pressure sensing. In some embodiments, sensor component 504 may include radar sensors. Sensor component 504 may include logic and processing components related to the charging process, including object detection, temperature measurement, motion measurement, motion control, safety measurement, communication components, etc., or any suitable combination thereof.

[0091] Figure 5B shows an exemplary layer of components arranged within a wireless charger 410 according to some embodiments of the present disclosure. In some embodiments, the transmitting coil 510 can be located above or below the central portion 502 of the wireless charger 410. Furthermore, various sensor components 504 can be arranged around the transmitting coil 510 of the wireless charger 410.

[0092] As shown in Figure 5B, the transmitting coil 510 can be configured to induce an electromagnetic field by receiving AC from the energy source 430. The transmitting coil 510 can operate in a range of powers, such as up to approximately 500 kilowatts (kW). In some embodiments, the transmitting coil 510 may be circular, and in some other embodiments, various shapes such as rectangular may be used.

[0093] In some embodiments, the wireless charger 410 may also include a PCB 520 (e.g., a control board for controlling the operation of the wireless charger 410). PCB 520 may be one or more PCBs, such as PCB 200, which includes embedded bimetallic thermocouples for sensing the temperature associated with the wireless charger 410, or may include such PCBs. Alternatively or additionally, other temperature sensors (e.g., thermistors) may be placed in and / or on PCB 520. Thus, PCB 520 can measure the temperature associated with the wireless charger 410 using bimetallic thermocouples or other temperature sensors for various purposes, such as detecting heated objects on the wireless charger 410.

[0094] In some embodiments, the PCB 520 can be placed in a layer below the transmitting coil 510. In addition to one or more bimetallic thermocouples, the PCB 520 may also include at least one processor and power supply module. Various electronic components, such as memory and communication modules, can be mounted on the PCB 520. These electronic components are provided as examples only, and the PCB 520 may include more or fewer components depending on the specific application.

[0095] Figure 5C shows exemplary temperature sensors integrated into a wireless charger 410 including a transmitting coil 510, according to some embodiments of the present disclosure. As shown in Figure 5C, a plurality of temperature sensors 506 and 508 may be positioned above or below the central portion 502 of the wireless charger 410. The plurality of temperature sensors 506 and 508 may include any suitable combination of bimetallic thermocouples, thermistors, or other types of temperature sensors. In some embodiments, the number of temperature sensors 506 and / or 508 may be determined based on the area of ​​the wireless charger 410, the type of temperature sensors used, and the desired application. The minimum size of the object to be thermally detected may affect the number of temperature sensors included in the wireless charger 410. In some embodiments, there may be more than 500 temperature sensors 506 and / or 508 integrated into the wireless charger 410 to detect a heated object with a maximum dimension of about 50 millimeters (mm). For example, there may be more than 500 bimetallic thermocouples embedded in one or more metal layers of the PCB 520, or more than 500 surface-mount thermocouples. To detect smaller objects, more temperature sensors may be included in the wireless charger 410. Conversely, to detect larger objects, fewer temperature sensors may be included in the wireless charger. In some other embodiments, more than 100 temperature sensors, such as thermistors, may be present in and / or on the PCB 520 to detect a heated object having a length of approximately 50 mm.

[0096] Figure 5D shows an exemplary representation of an object 550 on a wireless charger 410 according to an embodiment of the present disclosure. The object 550 may be a metallic object placed on the wireless charger 410 during the wireless charging process. Therefore, the object 550 may be heated. The object 550 can be detected using temperature sensors 506 and / or 508 (e.g., bimetallic thermocouples and / or other types of temperature sensors).

[0097] In some embodiments, the number of temperature sensors 506 and / or 508 may be determined based on the size of the object 550. More specifically, the surface of the wireless charger 410 may not dissipate or conduct heat due to its low thermal conductivity. Therefore, a large portion of the heat generated during the wireless charging process may accumulate on the object 550. Thus, the density of temperature sensors 506 and / or 508 may be correlated with the size of the object 550. For example, if the object 550 is a coin with a diameter of 50 mm, the number of temperature sensors 506 and / or 508 may need to be such that the wireless charger 410 is covered by the temperature sensing capability of the temperature sensors every 50 mm (e.g., 100, 200, 300, 400, 500, etc., depending on the surface area of ​​the wireless charger 410).

[0098] conclusion The foregoing disclosure is not intended to limit this disclosure to the exact form or specific field of use disclosed. Therefore, various alternative embodiments and / or modifications to this disclosure, whether expressly described or implied herein, are possible in light of this disclosure. Having described embodiments of this disclosure in this manner, those skilled in the art will recognize that changes in form and detail can be made without departing from the scope of this disclosure. Therefore, this disclosure is limited only by the claims.

[0099] It should be understood that not all objectives or benefits may necessarily be achieved in accordance with any specific example described herein. Therefore, for example, a person skilled in the art will understand that some examples may be implemented to achieve or optimize one or more of the benefits taught herein, without necessarily achieving other objectives or benefits that may be taught or suggested herein.

[0100] All processes described herein can be fully automated and implemented through software code modules executed by a computing system including a computer or processor. The code modules may be stored in any type of non-temporary computer-readable medium or other computer storage device. Some or all of the methods may be implemented in dedicated computer hardware.

[0101] Many other variations not described herein will be apparent from this disclosure. For example, depending on the example, any particular operation, event, or function of any of the algorithms described herein may be executed in a different order, or added, integrated, or omitted entirely (for example, not all described operations or events are necessary for the implementation of the algorithm). Furthermore, in some examples, operations or events may be executed not sequentially, but simultaneously, for example, through multithreading, interrupt handling, or via multiple processors or processor cores, or on other parallel architectures. Furthermore, different tasks or processes may be executed by different machines and / or computing systems that can work together.

[0102] The various exemplary logic blocks and modules described in relation to the examples disclosed herein may be implemented or run by machines such as processing units or processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A processor may be a microprocessor, but in alternative examples, a processor may be a controller, microcontroller, or state machine, or a combination thereof. A processor may include electrical circuits for processing computer-executable instructions. In some examples, a processor includes an FPGA or other programmable device that performs logical operations without processing computer-executable instructions. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, a microprocessor combined with a DSP core, or any other such configuration. Although this specification primarily describes digital technologies, a processor may also primarily include analog components. Computing environments can include, but are not limited to, any type of computer system based on a microprocessor, mainframe computer, digital signal processor, portable computing device, device controller, or in-device computing engine.

[0103] Elements of methods, processes, routines, or algorithms described in relation to embodiments disclosed herein can be directly embodied in hardware, software modules executed by a processor device, or a combination of the two. Software modules may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disks, removable disks, CD-ROMs, or any other form of non-temporary computer-readable storage medium. An exemplary storage medium may be coupled to a processor device so that the processor device can read information from and write information to the storage medium. Alternatively, the storage medium may be integrated into the processor device. The processor device and storage medium may reside within an ASIC. The ASIC may reside within a user terminal. Alternatively, the processor device and storage medium may exist as separate components within a user terminal.

[0104] The processes described herein or shown in the figures of this disclosure can be initiated on demand by a user or system administrator in response to an event such as a predetermined or dynamically determined schedule, or in response to any other event. Once such a process is initiated, a set of executable program instructions stored in one or more non-temporary computer-readable media (e.g., hard drives, flash memory, removable media) can be loaded into the memory (e.g., RAM) of a server or other computing device. The executable instructions may then be executed by the hardware-based computer processor of the computing device. In some embodiments, such a process or part thereof can be implemented in series or in parallel on multiple computing devices and / or multiple processors.

[0105] In particular, conditional language such as “can,” “could,” “might,” or “may,” unless otherwise specified, is generally understood in context to convey that some examples include certain features, elements, and / or steps, while others do not. Thus, such conditional language does not necessarily mean that the features, elements, and / or steps are illustrative in any way, or that the examples necessarily contain logic for determining whether these features, elements, and / or steps should be included in or performed in any particular example, with or without user input or prompting.

[0106] Disjunctive language, such as the phrase "at least one of X, Y, and Z," is generally understood in its context to indicate that an item, term, etc., can be any of X, Y, or Z, or any combination thereof (e.g., X, Y, and / or Z), unless otherwise specified. Therefore, such disjunctive language is not intended, nor should it be intended, to mean that several examples each require at least one of X, at least one of Y, and at least one of Z to exist.

[0107] Any process description, element, or block in the flowcharts described herein and / or shown in the accompanying drawings should be understood as potentially representing a module, segment, or portion of code containing executable instructions for implementing a particular logical function or element in the process. As will be understood by those skilled in the art, alternative examples in which elements or functions may be deleted, executed, or described in an order different from the illustrated or described order, including substantially simultaneously or in reverse order, are included within the scope of the examples described herein, depending on the function they contain.

[0108] It should be emphasized that many variations and modifications can be made to the above examples, and these elements should be understood as being within the context of other acceptable examples. All such modifications and variations are intended to be included within the scope of this disclosure.

[0109] Any process description, element, or block in the flowcharts described herein and / or shown in the accompanying drawings should be understood as potentially representing a module, segment, or portion of code containing executable instructions for implementing a particular logical function or element in the process. As will be understood by those skilled in the art, alternative implementations in which elements or functions may be removed, executed, or described in an order different from the illustrated or described order, including substantially simultaneously or in reverse order, are included within the scope of the examples described herein, depending on the function they contain.

[0110] Unless otherwise specified, articles such as "a" or "an" should generally be interpreted as including one or more listed items. Therefore, phrases such as "devices configured to perform" are intended to include one or more listed devices. Such one or more listed devices can also be collectively configured to perform the stated descriptions. For example, "processors configured to perform descriptions A, B, and C" may include a first processor configured to perform description A, which operates in conjunction with a second processor configured to perform descriptions B and C.

Claims

1. A printed circuit board (PCB), wherein the printed circuit board (PCB) is A thermocouple embedded in the PCB, wherein the thermocouple includes a first metal trace and a second metal trace, The thermocouple is configured to generate a voltage that indicates temperature. Printed circuit board (PCB).

2. The PCB according to claim 1, wherein the first metal trace comprises copper and the second metal trace comprises constantan.

3. The PCB according to claim 1, further comprising a dielectric layer disposed between the first metal trace and the second metal trace.

4. The PCB according to claim 3, further comprising a second dielectric layer and a third dielectric layer, wherein the first metal trace and the second metal trace are disposed between the second dielectric layer and the third dielectric layer.

5. The PCB according to claim 1, further comprising a second thermocouple embedded in the PCB, wherein the second thermocouple is configured to generate a second voltage indicating a second temperature, and the temperature and the second temperature are associated with different locations.

6. The PCB according to claim 5, wherein the first metal trace of the second thermocouple has an end that is short-circuited to the first metal trace of the thermocouple, and the second metal trace of the second thermocouple has an end that is short-circuited to the second metal trace of the thermocouple.

7. The PCB according to claim 5, wherein the thermocouple and the second thermocouple are arranged in parallel.

8. The PCB according to claim 5, wherein the thermocouple and the second thermocouple are connected to the same hot junction.

9. The thermocouple further comprises a surface layer placed on top of the thermocouple, The PCB according to claim 1, wherein the surface layer includes a coil configured to generate an electromagnetic field for wireless charging.

10. The PCB according to claim 1, further comprising 100 additional embedded thermocouples.

11. A wireless charging pad comprising the PCB described in claim 1.

12. A PCB assembly comprising the PCB and a processing circuit as described in claim 1, wherein the processing circuit is configured to determine the temperature based on the voltage.

13. It is a charging pad, A coil configured to generate an electromagnetic field for wireless charging, One or more sensors configured to generate one or more detection signals for thermally detecting an object placed on the coil, A processing circuit that communicates with one or more sensors, and is configured to control the operation of the charging pad based on at least one or more detection signals, A charging pad equipped with this feature.

14. The charging pad according to claim 13, wherein the charging pad is configured to thermally detect the object while the coil wirelessly transmits power to a second coil in the vehicle's vehicle pad.

15. The charging pad according to claim 13, wherein the one or more sensors include thermocouples embedded in a printed circuit board.

16. The charging pad according to claim 15, wherein the thermocouple is a T-type thermocouple.

17. The charging pad according to claim 13, wherein the one or more sensors include surface-mount thermocouples.

18. The charging pad according to claim 13, wherein the one or more sensors include 100 thermistors.

19. The processing circuit comprises at least, The steps include determining that the object is placed on the coil based on one or more detection signals, In response to the determination that the object is placed on the coil, the step of stopping the generation of the electromagnetic field in the coil, The charging pad according to claim 13, configured to control the operation of the charging pad based on at least one of the detection signals.

20. The charging pad according to claim 13, wherein the maximum dimension of the object is less than 50 millimeters.

21. A charging pad according to claim 13, configured to be connected to an external power source and sized to be positioned under a vehicle.

22. A method of wireless charging using thermal object detection, The steps include: wirelessly transmitting power between the wireless charging pad and the vehicle's vehicle pad, while thermally detecting an object placed between the wireless charging pad and the vehicle's vehicle pad; The steps include stopping the wireless transmission of power in response to the thermal detection, Methods that include...

23. The method according to claim 22, wherein the object is disposed on the surface of the wireless charging pad.

24. The method according to claim 22, wherein the object has a maximum dimension of 50 millimeters or less.

25. The method according to claim 22, wherein the object includes metal.

26. The method according to claim 22, wherein the thermal detection is performed using a thermocouple embedded in a printed circuit board.

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