NFC antenna components, manufacturing methods and electronic devices

Abstract

This invention discloses an NFC antenna assembly, its manufacturing method, and an electronic device. The manufacturing method of the NFC antenna assembly includes the following steps: preparing a PCB circuit board and electronic components, the electronic components including at least a first isolation device and a second isolation device; forming a circuit wiring layer, a first antenna segment, and a second antenna segment of a loop NFC antenna on the PCB circuit board; mounting the electronic components on the circuit wiring layer to form a current loop connecting the antenna matching circuit, the receiving circuit, and the first and second antenna segments of the loop NFC antenna; and connecting the first isolation device in series between the first antenna segment and the second antenna segment; and connecting the second isolation device in series between the receiving circuit and the second antenna segment. This invention solves the problem of low PCB antenna yield caused by antenna short circuits during PCB manufacturing.

Description

Technical Field

[0001] This invention relates to the field of electronic circuit technology, and in particular to an NFC antenna assembly, manufacturing method, and electronic device. Background Technology

[0002] During PCB manufacturing, due to process limitations, there is a certain probability of short circuits in adjacent antenna circuits when the line width is small and the line spacing is close, causing antenna failure. Since the antenna's matching circuit and antenna are physically part of the same network, flying probe testing is not possible after the antenna is fabricated on the PCB. The electronic components of the NFC antenna assembly must be placed on the PCB and programmed before testing can be performed. This results in unnecessary losses, significant material waste, and complex testing, leading to decreased manufacturing efficiency and yield of the NFC antenna assembly. Summary of the Invention

[0003] The main objective of this invention is to propose an NFC antenna assembly, manufacturing method, and electronic device, aiming to solve the problem of reduced antenna yield on PCB printed circuit boards caused by antenna short circuits during PCB manufacturing.

[0004] To achieve the above objectives, the present invention proposes a method for manufacturing an NFC antenna assembly, the method comprising the following steps:

[0005] Prepare a PCB circuit board and electronic components, wherein the electronic components include at least a first isolation device and a second isolation device;

[0006] A circuit wiring layer, a first antenna segment, and a second antenna segment of a ring-shaped NFC antenna are formed on the PCB circuit board.

[0007] The electronic components are mounted on the circuit wiring layer to form a current loop connecting the antenna matching circuit, the receiving circuit, and the first and second antenna segments of the loop NFC antenna; and,

[0008] The first isolation device is connected in series between the first antenna segment and the second antenna segment; the second isolation device is connected in series between the receiving circuit and the second antenna segment.

[0009] Optionally, after the step of forming a circuit wiring layer, a first antenna segment, and a second antenna segment of the loop NFC antenna on the PCB circuit board, the method for manufacturing the NFC antenna assembly further includes:

[0010] Short-circuit tests were performed on the first and second antenna segments of the ring NFC antenna.

[0011] Optionally, the step of short-circuiting the first and second antenna segments of the ring NFC antenna specifically includes:

[0012] Connect both ends of the first antenna segment to the first short-circuit test device, and set the test points of the short-circuit test device on the first antenna segment and the first antenna segment respectively;

[0013] And / or, connect both ends of the second antenna segment to the second short-circuit test device, and set the test points of the short-circuit test device on the first antenna segment and the first antenna segment respectively.

[0014] Optionally, the first isolation device has a zero-ohm resistance;

[0015] And / or, the second isolation device has a zero-ohm resistance.

[0016] Optionally, the method for manufacturing the NFC antenna assembly further includes:

[0017] Multiple conductive vias are provided on the PCB circuit board to electrically connect the first antenna segment to the first isolation device and the antenna matching circuit through the conductive vias; and,

[0018] The second antenna segment is electrically connected to the second isolation device through the conductive via.

[0019] Optionally, the NFC antenna assembly further includes:

[0020] Prepare an NFC chip and mount the NFC chip onto the circuit wiring layer; and,

[0021] The NFC chip is programmed.

[0022] Optionally, the operating frequency of the ring NFC antenna is 13.56MHz.

[0023] Optionally, the step of forming the circuit wiring layer, the first antenna segment, and the second antenna segment of the loop NFC antenna on the PCB circuit board using a dual-wire parallel winding process specifically includes:

[0024] A conductor is formed on one surface of the PCB circuit board;

[0025] The conductors formed on the surface of the PCB circuit board are etched to form antenna patterns for the first and second antenna segments of the ring NFC antenna, and to form a circuit wiring layer for mounting the antenna matching circuit, the receiving circuit, the first isolation device and the second isolation device.

[0026] The present invention also proposes an NFC antenna assembly, which is manufactured by the NFC antenna assembly manufacturing method described above.

[0027] The invention also proposes an electronic device including the NFC antenna assembly described above.

[0028] This invention forms an antenna mounting area and a circuit mounting area on a PCB circuit board. The antenna mounting area is located outside the circuit mounting area, and a first antenna segment and a second antenna segment are disposed on the antenna mounting area. This invention divides the NFC antenna into a first antenna segment and a second antenna segment. The first antenna segment is connected to an antenna matching circuit for impedance matching with the NFC antenna, and the second antenna segment is connected to a receiving circuit for converting the wireless data signal generated by the NFC antenna into an electrical signal. This invention also includes a first isolation device connected in series between the first antenna segment and the second antenna segment, and a second isolation device connected in series between the receiving circuit and the second antenna segment. Under the isolation of these components, the first antenna segment is connected to the network formed with the antenna matching circuit, and the second antenna segment is connected to the network formed with the receiving circuit. In other words, the first antenna segment and the second antenna segment belong to two different networks. After the NFC antenna is formed on the PCB, or after the NFC antenna is manufactured, it can be connected to a short-circuit test device to complete the short-circuit test of the NFC antenna. This invention solves the problem of PCB printed circuit board antenna yield caused by antenna short circuit during PCB manufacturing, which is conducive to improving the manufacturing efficiency and yield of NFC antennas. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0030] Figure 1 This is a flowchart illustrating an embodiment of the method for manufacturing an NFC antenna assembly according to the present invention;

[0031] Figure 2 This is a flowchart illustrating another embodiment of the method for manufacturing the NFC antenna assembly of the present invention;

[0032] Figure 3 This is a flowchart illustrating another embodiment of the method for manufacturing the NFC antenna assembly of the present invention;

[0033] Figure 4 This is a schematic diagram of the circuit structure of an embodiment of the NFC antenna assembly of the present invention;

[0034] Figure 5 This is a schematic diagram of the structure of an embodiment of the NFC antenna assembly of the present invention;

[0035] Figure 6 This is a functional module diagram of an embodiment of the NFC antenna assembly of the present invention.

[0036] Explanation of icon numbers:

[0037]

[0038]

[0039] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0041] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0042] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0043] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0044] This invention proposes a method for manufacturing an NFC antenna assembly.

[0045] Reference Figure 1 , Figure 4 , Figure 5 and Figure 6 In one embodiment of the present invention, the method for manufacturing the NFC antenna assembly includes the following steps:

[0046] Step S100: Prepare PCB circuit board 100 and electronic components, wherein the electronic components include at least a first isolation device 20 and a second isolation device 30;

[0047] Step S200: A circuit wiring layer, a first antenna segment 11 and a second antenna segment 12 of the loop NFC antenna 10 are formed on the PCB circuit board 100.

[0048] In this embodiment, the first antenna segment 11 and the second antenna segment 12 are arranged in a ring around the periphery of the PCB circuit board 100. The ring area formed by the ring NFC antenna 10 can serve as the circuit mounting area for the NFC antenna assembly, that is, the electronic components of the NFC antenna assembly are mounted in the ring area formed by the ring NFC antenna 10. PCB printing is performed in the ring area to form a circuit wiring layer. The NFC antenna in this embodiment can be a planar antenna, specifically manufactured using one of the following processes: physical vapor deposition, chemical vapor deposition, evaporation, sputtering, electroplating, or chemical plating. The NFC antenna can be formed on the PCB circuit board 100 through printed circuit wiring. The NFC antenna can be directly formed on the PCB circuit board 100 through processes such as copper plating and etching. The NFC antenna can also be implemented using an FPC antenna. The FPC antenna can be glued to the PCB circuit board 100 with adhesive material, or it can be embedded in the PCB circuit board 100 by pre-embedding, or the antenna pattern of the formed NFC antenna can be pressed onto the PCB circuit board 100 through other processes. When the NFC antenna is mounted on the control board, it can be implemented using PCB circuit routing, forming antenna traces on the PCB circuit board 100. Specifically, the loop NFC antenna 10 and the pads for mounting electronic components in the NFC antenna circuit 200 can be routed on one side of the PCB circuit board 100. The first antenna segment 11 and the second antenna segment 12 can be formed using a dual-wire winding process, with the number of turns, length, and width of the first antenna segment 11 and the second antenna segment 12 being equal. The thickness, size, and shape of the PCB circuit board 100 can be customized according to the actual application product and environment to meet different application requirements. In one specific embodiment, the PCB circuit board 100 can be square, such as rectangular or square.

[0049] Step S300: Install the electronic components on the circuit wiring layer to form a current loop connecting the antenna matching circuit 50, the receiving circuit 40, and the first antenna segment 11 and the second antenna segment 12 of the loop NFC antenna 10.

[0050] In this embodiment, after the circuit wiring layer is fabricated, a pick-and-place machine can be used to mount electronic components onto the corresponding pads of the circuit wiring layer. The electrical connections between the various electronic components are achieved through the circuit traces formed by the circuit wiring layer, thereby forming an antenna matching circuit 50, a receiving circuit 40, an EMC filter circuit 60, and a corresponding current loop. When the antenna matching circuit 50, the receiving circuit 40, the EMC filter circuit 60, etc. are working, they can realize the NFC antenna circuit 200 with NFC function.

[0051] The NFC antenna is used to transmit wireless data signals to external NFC devices via near-field coupling. The NFC antenna receives wireless data signals from the external device, converts them into electrical signals, and transmits these electrical signals to the receiving circuit 40. The receiving circuit 40 then transmits the electrical signals to the NFC chip U1, establishing a connection with the external NFC device via near-field coupling and transmitting signals. The NFC antenna transmits electromagnetic signals to external NFC devices, such as mobile terminals and smart cards, via near-field coupling. The NFC antenna circuit 200 transmits and receives wireless data signals and performs corresponding conditioning, such as impedance matching. The NFC antenna is connected to the NFC chip U1 through the antenna matching circuit 50 and the receiving circuit 40. It transmits wireless data signals from the NFC chip U1 or receives wireless data signals transmitted from the external device via a radio frequency electromagnetic field. The NFC antenna circuit 200 can be a passive topology. When operating, the NFC antenna circuit 200 can obtain energy from the electromagnetic field emitted by the external device without consuming the energy of the electronic device to which the antenna circuit is applied. The electronic device used in the NFC antenna circuit 200 of this embodiment can function as either a transponder or a reader. When used as a transponder, it possesses a unique electronic code, which can be identified by external devices to enable card swiping, access control, mobile payments, etc. When used as a reader, it can read data from other external devices, enabling short-range data transmission, such as audio and images. The primary operating frequency of the NFC device can be a high frequency of 13.56MHz. The antenna matching circuit 50 performs impedance matching with the NFC antenna when its frequency is within the operating frequency range, thereby increasing the effective bandwidth of the NFC antenna. The antenna matching circuit 50 is connected between the NFC antenna and the NFC chip U1. The antenna matching circuit 50 can adjust the resonant frequency of the antenna and match the impedance towards the NFC chip U1 with the impedance towards the antenna to increase the communication efficiency of the NFC antenna assembly. The operating frequency range is the range required for NFC sensing (such as payment, door unlocking, etc.), such as around 13MHz.

[0052] Step S400: The first isolation device 20 is connected in series between the first antenna segment 11 and the second antenna segment 12; the second isolation device 30 is connected in series between the receiving circuit 40 and the second antenna segment 12.

[0053] In this embodiment, the NFC antenna is divided into two antenna segments, namely, the first antenna segment 11 and the second antenna segment 12 are spaced apart from each other, and there is no direct connection between the two antenna segments. Each antenna segment has two ends, referred to as the first end and the second end, respectively. The first end of the first antenna segment 11 is connected to the antenna matching circuit 50, and the second end of the first antenna is connected to one end of the first isolating device 20. The first end of the second antenna segment 12 is connected to the receiving circuit 40, and the second end of the second antenna is connected to the other end of the first isolating device 20. The other end of the first isolating device 20 is also connected to the ground terminal of the NFC antenna circuit 200. That is, the second end of the second antenna segment 12 is electrically connected to the first antenna under the isolation effect of the first isolating device 20.

[0054] When the NFC antenna circuit 200 is working, for example, the NFC antenna circuit 200 receives externally input wireless data signals through the NFC antenna. Specifically, the second antenna segment 12 receives electromagnetic energy, which is then output to the receiving circuit 40 via the second antenna segment 12 and the second isolation device 30. When the NFC antenna circuit 200 transmits wireless data signals to the outside through the NFC antenna, the first antenna segment 11 and the second antenna segment 12 convert the electrical signals into wireless data signals and radiate electromagnetic energy to the outside. Under the action of the NFC antenna 10, the electromagnetic energy is radiated out. Specifically, the electrical signal is output to the first antenna segment 11 via the antenna matching circuit 50 and the first isolation device 20, and then radiated out by the first antenna segment 11.

[0055] With the isolation provided by the first isolator 20 and the second isolator 30, the first antenna segment 11 is connected to the network formed with the antenna matching circuit 50, and the second antenna segment 12 is connected to the network formed with the receiving circuit 40. The receiving circuit 40 and the antenna matching network belong to two different networks. When manufacturing the NFC antenna, the first antenna segment 11 and the second antenna segment 12 are separated from each other during antenna routing, thus achieving physical isolation. Furthermore, with the isolation provided by the first isolator 20 and the second isolator 30, flying probe testing (i.e., short circuit testing) during PCB production can detect whether there is a short circuit between adjacent antennas.

[0056] This invention forms an antenna mounting area and a circuit mounting area on a PCB circuit board 100. The antenna mounting area is located outside the circuit mounting area, and a first antenna segment 11 and a second antenna segment 12 are disposed on the antenna mounting area. This invention divides the NFC antenna into a first antenna segment 11 and a second antenna segment 12. The first antenna segment 11 is connected to an antenna matching circuit 50 for impedance matching with the NFC antenna, and the second antenna segment 12 is connected to a receiving circuit 40 for converting the wireless data signal generated by the NFC antenna into an electrical signal. This invention also provides a first isolation device 20 connected in series between the first antenna segment 11 and the second antenna segment 12, and a second isolation device 30 connected in series between the receiving circuit 40 and the second antenna segment 12. Under the isolation of these components, the first antenna segment 11 is connected to the network formed with the antenna matching circuit 50, and the second antenna segment 12 is connected to the network formed with the receiving circuit 40. In other words, the first antenna segment 11 and the second antenna segment 12 belong to two different networks. After the NFC antenna is formed on the PCB, or after the NFC antenna is manufactured, it can be connected to a short-circuit test device to complete the short-circuit test of the NFC antenna. This invention solves the problem of PCB printed circuit board antenna yield caused by antenna short circuit during PCB manufacturing, which is conducive to improving the manufacturing efficiency and yield of NFC antennas.

[0057] Reference Figures 2 to 6 In one embodiment, after the step of forming a circuit wiring layer, a first antenna segment 11 and a second antenna segment 12 of the loop NFC antenna 10 on the PCB circuit board 100, the method for manufacturing the NFC antenna assembly further includes:

[0058] Step S500: Perform a short-circuit test on the first antenna segment 11 and the second antenna segment 12 of the loop NFC antenna 10. Specifically,

[0059] Step S510: Connect both ends of the first antenna segment 11 to the first short-circuit test device, and set the test points of the short-circuit test device on the first antenna segment 11 and the first antenna segment 11 respectively; and / or,

[0060] Step S520: Connect both ends of the second antenna segment 12 to the second short-circuit test device, and set the test points of the short-circuit test device on the first antenna segment 11 and the first antenna segment 11 respectively.

[0061] The first antenna segment 11 and the second antenna segment 12 can be tested using a short-circuit testing device. Specifically, the first antenna segment 11 can be connected to the power supply circuit constructed in the short-circuit testing device to provide current to the first antenna segment 11, forming a current loop between the first antenna segment 11 and the short-circuit testing device. Then, two test points, such as test probes, are connected to the first antenna segment 11 and the second antenna segment 12. It is understood that when the second antenna segment 12 is not connected to the power supply circuit constructed in the short-circuit testing device, a current loop cannot be formed between the second antenna segment 12 and the short-circuit testing device. Therefore, under normal circumstances, the first antenna segment 11 and the second antenna segment 12 are equivalent to an open circuit. If the short-circuit testing device detects the presence of an electrical signal in the first antenna segment 11 and the second antenna segment 12, it can be determined that the first antenna segment 11 and the second antenna segment 12 are stuck together, and a short circuit point exists. Conversely, if the short-circuit test device detects no electrical signal in the first antenna segment 11 and the second antenna segment 12, it can be determined that there is no adhesion between the first antenna segment 11 and the second antenna segment 12, and therefore no short circuit. Similarly, the second antenna segment 12 can be connected to the power supply circuit constructed in the short-circuit test device to provide current to the first antenna segment 11, forming a current loop between the second antenna segment 12 and the short-circuit test device. Then, two test points, such as test probes, can be connected to the first antenna segment 11 and the second antenna segment 12. If the short-circuit test device detects an electrical signal in the first antenna segment 11 and the second antenna segment 12, it can be determined that there is adhesion between the first antenna segment 11 and the second antenna segment 12, and therefore a short circuit. Conversely, if the short-circuit test device detects no electrical signal in the first antenna segment 11 and the second antenna segment 12, it can be determined that there is no adhesion between the first antenna segment 11 and the second antenna segment 12, and therefore no short circuit.

[0062] Reference Figures 1 to 6 In one embodiment, the first isolation device 20 has a zero-ohm resistance;

[0063] And / or, the second isolation device 30 has a zero-ohm resistance.

[0064] In this embodiment, the first isolation device 20 and the second isolation device 30 can both be implemented using zero-ohm resistors. The two zero-ohm resistors can isolate the first antenna segment 11 and the second antenna segment 12 into two different networks, thereby physically isolating them. This allows for flying probe testing during PCB production, i.e., short circuit testing, to detect whether there is a short circuit between adjacent antennas.

[0065] Reference Figures 1 to 6 In one embodiment, the method for manufacturing the NFC antenna assembly further includes:

[0066] A plurality of conductive vias are provided on the PCB circuit board 100 to electrically connect the first antenna segment 11 to the first isolation device 20 and the antenna matching circuit 50 through the conductive vias; and,

[0067] The second antenna segment 12 and the second isolation device 30 are electrically connected through the conductive via.

[0068] In this embodiment, the PCB circuit board 100 has two opposing side surfaces, namely a first side surface and a second side surface. The receiving circuit 40, antenna matching circuit 50, EMC filtering circuit 60, and NFC chip U1 in the NFC antenna circuit 200 can be disposed on one side surface of the PCB circuit board 100 or on the opposing side surfaces of the PCB circuit board 100. To reduce the use of binding wires and flying wires, this embodiment provides multiple conductive vias on the PCB circuit board 100, so that the first antenna segment 11 and the second antenna segment 12 in the ring NFC antenna 10 belong to two different networks. Electrical connection with electronic components disposed in the ring mounting area can be achieved through conductive vias and circuit wiring.

[0069] Reference Figures 1 to 6 In one embodiment, after the steps of fabricating the circuit wiring layer, the first antenna segment, and the second antenna segment of the loop NFC antenna on the PCB circuit board 100, the method for fabricating the NFC antenna assembly further includes:

[0070] Prepare NFC chip U1, and install the NFC chip U1 on the circuit wiring layer; and,

[0071] The NFC chip U1 is programmed.

[0072] In this embodiment, after the NFC chip U1 is mounted on the PCB circuit board 100 using a surface mount technology (SMT) or similar process, the program for the electronic device to which the NFC chip U1 is applied can be programmed into the NFC chip U1. The NFC chip U1 is a chip with both communication and computing capabilities, and can perform corresponding NFC functions. When the NFC chip U1 is used in an electronic device, it can interact with the target device through the NFC antenna circuit 200. The NFC chip U1 can be used to implement card-mode functions, such as replacing public transport cards, shopping mall card swiping, and access control. In this invention, the target device is a card reader. When the target device is a card reader, the NFC chip U1 sends authentication information to the card reader through a communication link and receives the authentication result response from the card reader. After successful authentication, the corresponding card function is executed. The NFC chip U1 can also be used for point-to-point data transmission between electronic devices, enabling short-range data transmission with the target device, such as exchanging data or music files between two electronic devices. It can also be used with NFC Bluetooth devices, such as Bluetooth headsets and smart bracelets.

[0073] The NFC chip U1 integrates a main control chip and an NFC read / write chip. The main control chip has a pre-set NFC algorithm. The main control chip communicates with the NFC read / write chip. When the NFC read / write chip is connected to an external NFC device via the NFC antenna circuit 20010, the NFC read / write chip outputs a connection signal to the main control chip, enabling the main control chip to control and respond based on the received information. The main control chip can also output control signals to the NFC read / write chip for information processing based on the connection signal fed back by the NFC read / write chip, such as outputting reset signals, initialization signals, read / write signals, and switch signals. Based on the NFC antenna circuit 200, the NFC chip U1 can operate with external NFC devices in modes including but not limited to read / write mode, point-to-point transmission mode, and smart card mode. Specifically, the NFC antenna circuit 200 enables wireless data signal communication between the NFC chip U1 and external NFC devices. When the NFC chip U1 establishes a connection with an external NFC device, it sends a connection signal back to the main control chip. The main control chip outputs a control signal to the NFC read / write chip according to the connection signal fed back by the NFC read / write chip, so as to control the NFC read / write chip to perform wireless data signal reading and writing operations, thereby realizing the NFC function between the NFC circuit and the external device.

[0074] The NFC chip U1 has two signal transmitting terminals TX1 and TX2, a signal receiving terminal RX1, a bias voltage output terminal VMID, and a ground terminal TVSS. The two signal transmitting terminals TX1 and TX2 are connected one-to-one with the two input terminals of the EMC filter circuit 60 in the NFC antenna circuit 200. The signal receiving terminal RX1 and the bias voltage output terminal VMID are connected to the signal receiving terminal RX1 and the bias voltage output terminal VMID of the receiving circuit 40. The ground terminal TVSS is used for grounding. The NFC chip U1 is connected to the NFC antenna circuit 200 through the two signal transmitting terminals TX1 and TX2 and the signal receiving terminal RX1 to exchange wireless data signals, realizing wireless data signal transmission or stopping transmission.

[0075] In some embodiments, the NFC antenna assembly also has a crystal oscillator (not shown) to provide a clock reference for the NFC chip U1, while the chip has high output power, making the DC / DC boost converter an unnecessary external component. These advantages help save on component costs and board space.

[0076] Reference Figures 1 to 6 In one embodiment, the step of forming a circuit wiring layer, a first antenna segment 11, and a second antenna segment 12 of the loop NFC antenna 10 on the PCB circuit board 100 specifically includes:

[0077] A conductor is formed on one surface of the PCB circuit board 100;

[0078] The conductors formed on the surface of the PCB circuit board 100 are etched to form the antenna pattern of the first antenna segment 11 and the second antenna segment 12 of the ring NFC antenna 10, and to form a circuit wiring layer for mounting the antenna matching circuit 50, the receiving circuit 40, the first isolation device 20 and the second isolation device 30.

[0079] In this embodiment, the conductor can be copper foil, which is laid on the PCB circuit board 100 and etched according to a preset circuit design to form a circuit wiring layer. The conductor can also be made of ferrite material doped with anti-interference capabilities.

[0080] Reference Figures 1 to 6 In one embodiment, the method for manufacturing the NFC antenna assembly further includes:

[0081] Electronic components are mounted on the PCB circuit board 100 to form an EMC filter circuit 60.

[0082] An EMC filter circuit 60 is connected in series between the signal transmitting end and the antenna matching circuit 50.

[0083] Understandably, since the NFC frequency (13.56MHz) is relatively low, common negative impedance circuit components often have high-frequency interference reduction circuits (above 1GHz). Therefore, in this embodiment, the high-frequency signal in the radio frequency signal can be filtered out by the EMC filter circuit 60, thereby solving the high-frequency interference to the NFC antenna.

[0084] Reference Figures 1 to 6 In one embodiment, the signal transmitting end includes a first signal transmitting end TX1 and a second signal transmitting end TX2; the EMC filtering circuit 60 includes a first inductor L1, a second inductor L2, a first capacitor C1 and a second capacitor C2, one end of the first inductor L1 is connected to the first signal transmitting end TX1, and the other end of the first inductor L1 is connected to the antenna matching circuit 50; one end of the second inductor L2 is connected to the second signal transmitting end TX2, and the other end of the second inductor L2 is connected to the antenna matching circuit 50; the first capacitor C1 is connected in series between the first inductor L1 and ground; the second capacitor C2 is connected in series between the second inductor L2 and ground.

[0085] In this embodiment, the first signal transmitting terminal TX1 and the second signal transmitting terminal TX2 can be connected to the two transmitting terminals of the NFC chip U1. The two transmitting terminals output differential signals with equal amplitude and opposite phase to drive the antenna. The first inductor L1 and the first capacitor C1 form a low-pass filter circuit, and the second inductor L2 and the second capacitor C2 form another low-pass filter circuit.

[0086] Reference Figures 1 to 6 In one embodiment, the antenna matching circuit 50 includes:

[0087] The third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, and the sixth capacitor C6 are connected in series between the EMC filter circuit 60 and the first antenna segment 11; the fourth capacitor C4 is connected in series between the EMC filter circuit 60 and the second antenna segment 12; the fifth capacitor C5 is connected in series between the third capacitor C3 and ground; and the sixth capacitor C6 is connected in series between the fourth capacitor C4 and ground.

[0088] In this embodiment, the third capacitor C3 and the fourth capacitor C4 are series capacitors, and the fifth capacitor C5 and the sixth capacitor C6 are parallel capacitors. In practical applications, the internal resistance of the NFC receiving antenna can be measured by impedance measurement, and the capacitive reactance and phase deviation of the antenna matching circuit 50 can be measured by a network analyzer. The capacitance values ​​of the third capacitor C3, the fourth capacitor C4, the fifth capacitor C5, and the sixth capacitor C6 can be designed and adjusted so that the internal resistance of the NFC antenna is consistent with the impedance of the antenna matching circuit 50, so that the impedance provided by the antenna matching circuit 50 can match the NFC antenna.

[0089] Reference Figures 1 to 6 In one embodiment, the NFC antenna assembly further includes a signal receiving terminal RX and a bias voltage input terminal;

[0090] The receiving circuit 40 includes a first resistor R1, a second resistor R2, and a seventh capacitor C3. One end of the first resistor R1 is connected to the bias voltage input terminal, and the other end of the first resistor R1 is interconnected with the signal receiving terminal RX and one end of the second resistor R2. The other end of the second resistor R2 is connected to one end of the seventh capacitor C3, and the other end of the seventh capacitor C3 is connected to the second isolation device 30.

[0091] In this embodiment, the first resistor R1 acts as a voltage divider, positioned between the signal receiver RX and the bias voltage input terminal. The bias voltage connected to the first resistor R1 from the bias voltage input terminal Vmid can increase the voltage drive of the signal receiver RX. The NFC antenna converts received wireless data signals and interference signals into electrical signals and outputs them to the seventh capacitor C3 and the second resistor R2 of the receiving circuit 40. Under the coupling and filtering effect of the seventh capacitor C3, the signals are transmitted to the NFC chip U1 via the second resistor R2.

[0092] It is understandable that after programming the NFC chip U11, product function testing can be performed on the NFC antenna assembly. However, compared to the NFC antenna fabricated on the printed circuit board (PCB), where the antenna and its matching circuit are physically part of the same network, a short circuit would prevent direct flying probe testing of the PCB NFC antenna, meaning internal short circuits could not be detected until product function testing. By this time, the PCB has already undergone SMT assembly and software programming, leading to unnecessary losses. This invention detects short circuits during flying probe testing, allowing PCBs with faulty antennas to be discarded, ensuring that only PCBs with functional antennas proceed to component assembly and programming. This optimized PCB antenna significantly reduces resource waste and testing complexity during component placement and also reduces the need for antenna testing.

[0093] This invention also proposes an NFC antenna assembly, which is manufactured using the aforementioned method. Specifically, it includes an NFC chip U1 and an NFC antenna circuit 200, with the NFC chip U1 electrically connected to the NFC antenna circuit 200. The NFC antenna circuit includes at least:

[0094] The ring-shaped NFC antenna 10 includes a first antenna segment 11 and a second antenna segment 12, wherein the first antenna segment 11 and the second antenna segment 12 are disposed in the antenna mounting area;

[0095] An antenna matching circuit 50 is disposed on the circuit mounting area. The antenna matching circuit 50 is connected to the first antenna segment 11 and is used to achieve impedance matching with the NFC antenna.

[0096] A receiving circuit 40 is disposed in the circuit mounting area; the receiving circuit 40 is connected to the second line segment 12 of the NFC antenna, which is used to convert the wireless data signal generated by the NFC antenna into an electrical signal;

[0097] A first isolation device 20 is disposed in the circuit mounting area; the first isolation device 20 is connected in series between the first antenna segment 11 and the second antenna segment 12.

[0098] The second isolation device 30 is disposed in the circuit mounting area; the second isolation device 30 is connected in series between the receiving circuit 40 and the second antenna segment 12.

[0099] The present invention also proposes an electronic device, including the NFC antenna circuit 200 as described above, or including the NFC antenna assembly as described above. The detailed structure of the NFC antenna circuit 200 and the NFC antenna assembly can be referred to the above embodiments, and will not be repeated here. It is understood that, since the above-described NFC antenna circuit 200 and NFC antenna assembly are used in the electronic device of the present invention, the embodiments of the electronic device of the present invention include all the technical solutions of all embodiments of the above-described NFC antenna circuit 200 and NFC antenna assembly, and the achieved technical effects are also completely the same, and will not be repeated here.

[0100] The mobile terminal can be a smartphone, computer, multimedia player, e-reader, wearable device, etc.

[0101] The above description is merely an optional embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for manufacturing an NFC antenna assembly, characterized in that, The method for manufacturing the NFC antenna assembly includes the following steps: Prepare a PCB circuit board and electronic components, wherein the electronic components include at least a first isolation device and a second isolation device, wherein the first isolation device is a zero-ohm resistor; and / or, the second isolation device is a zero-ohm resistor; A circuit wiring layer, a first antenna segment, and a second antenna segment of a ring-shaped NFC antenna are formed on the PCB circuit board. The electronic components are mounted on the circuit wiring layer to form a current loop connecting the antenna matching circuit, the receiving circuit, and the first and second antenna segments of the loop NFC antenna; and, The first isolating device is connected in series between the first antenna segment and the second antenna segment; the second isolating device is connected in series between the receiving circuit and the second antenna segment. The first end of the first antenna segment is connected to the antenna matching circuit, the second end of the first antenna segment is connected to one end of the first isolating device, the first end of the second antenna segment is connected to the receiving circuit through the second isolating device, and the second end of the second antenna segment is connected to the other end of the first isolating device. The first antenna segment is connected to the network formed with the antenna matching circuit, and the second antenna segment is connected to the network formed with the receiving circuit. The first isolating device and the second isolating device physically isolate the first antenna segment and the second antenna segment into two different networks.

2. The method for manufacturing the NFC antenna assembly as described in claim 1, characterized in that, After the steps of forming the circuit wiring layer, the first antenna segment and the second antenna segment of the loop NFC antenna on the PCB circuit board, the method for manufacturing the NFC antenna assembly further includes: Short-circuit tests were performed on the first and second antenna segments of the ring NFC antenna.

3. The method for manufacturing the NFC antenna assembly as described in claim 2, characterized in that, The steps of performing short-circuit testing on the first and second antenna segments of the ring NFC antenna specifically include: Connect both ends of the first antenna segment to the first short-circuit test device, and set the test points of the short-circuit test device on the first antenna segment and the first antenna segment respectively; And / or, connect both ends of the second antenna segment to the second short-circuit test device, and set the test points of the short-circuit test device on the first antenna segment and the first antenna segment respectively.

4. The method for manufacturing the NFC antenna assembly as described in claim 1, characterized in that, The method for manufacturing the NFC antenna assembly further includes: Multiple conductive vias are provided on the PCB circuit board to electrically connect the first antenna segment to the first isolation device and the antenna matching circuit through the conductive vias; and, The second antenna segment is electrically connected to the second isolation device through the conductive via.

5. The method for manufacturing the NFC antenna assembly as described in claim 1, characterized in that, The NFC antenna assembly also includes: Prepare an NFC chip and mount the NFC chip onto the circuit wiring layer; and, The NFC chip is programmed.

6. The method for manufacturing an NFC antenna assembly as described in any one of claims 1 to 5, characterized in that, The ring-shaped NFC antenna operates at a frequency of 13.56 MHz.

7. The method for manufacturing an NFC antenna assembly as described in any one of claims 1 to 5, characterized in that, The steps of forming the circuit wiring layer, the first antenna segment, and the second antenna segment of the loop NFC antenna on the PCB circuit board using a dual-wire winding process specifically include: A conductor is formed on one surface of the PCB circuit board; The conductors formed on the surface of the PCB circuit board are etched to form antenna patterns for the first and second antenna segments of the ring NFC antenna, and to form a circuit wiring layer for mounting the antenna matching circuit, the receiving circuit, the first isolation device and the second isolation device.

8. An NFC antenna assembly, characterized in that, The NFC antenna assembly is manufactured by the method of manufacturing an NFC antenna assembly as described in any one of claims 1 to 7.

9. An electronic device, characterized in that, Includes the NFC antenna assembly as described in claim 8.

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