FPC loop antenna

Abstract

The present disclosure provides a FPC loop antenna, characterized in that, for an NFC ring, comprising a flexible substrate, an insulating film and a copper layer conductor; the copper layer conductor is distributed on the front and back surfaces of the flexible substrate, and realizes interlayer conduction through electroplated through holes; the insulating film is covered on the front and back surfaces of the flexible substrate and covers the copper layer conductor; the FPC loop antenna is arranged in the NFC ring through end-to-end welding. The electromagnetic field vertically penetrating the NFC ring can be formed after the end-to-end welding, thereby improving the reading efficiency of the RFID and the production efficiency of the NFC ring.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of near field communication device, in particular to an FPC annular antenna. BACKGROUND

[0002] NFC (Near Field Communication) technology has been widely used in production and life at present, and NFC ring product has become a popular product of applying NFC technology due to its practicability and portability.

[0003] At present, the conventional NFC ring adopts a hollow coil wound by copper wire, and the coil is connected with a COB (Chip-on-board) or DFN (Dual Flat No-lead Package) module processed by soldering with an RFID (Radio Frequency Identification) chip, which has a long process flow and cannot directly adjust frequency. Different ring sizes (American standard 6#~13#) need to set different parameters such as wire diameter and coil winding number to reach the standard frequency of RFID HF corresponding protocol (such as ISO14443A, ISO15693). SUMMARY

[0004] The embodiments of the present disclosure at least provide an FPC annular antenna, which can form an electromagnetic field vertically penetrating the NFC ring after the first end and the last end are welded, thereby improving the reading efficiency of the RFID and the production efficiency of the NFC ring.

[0005] The embodiments of the present disclosure provide an FPC annular antenna for an NFC ring, which comprises a flexible substrate, an insulating film and a copper layer conductor belt.

[0006] The copper layer conductor belt is distributed on the front and back surfaces of the flexible substrate and realizes interlayer conduction through an electroplated through hole; the insulating film covers the front and back surfaces of the flexible substrate and covers the copper layer conductor belt.

[0007] The FPC annular antenna is welded at the first end and the last end and arranged in the NFC ring.

[0008] In some embodiments, the length of the FPC annular antenna is 65.5mm or 75.5mm.

[0009] In some embodiments, the thickness of the copper layer conductor belt is 1.5 or 2.0oz, and the surface electroplating thickness is a nickel-gold layer of 1~2μ".

[0010] In some embodiments, the single-sided line spacing of the copper layer conductor belt is greater than 2 times the line width.

[0011] In some embodiments, the width of the FPC annular antenna is 5mm.

[0012] In some embodiments, the FPC loop antenna is provided with a long end welding site and a short end welding site, both of which are provided with electroplated through holes with a diameter of 0.15 mm, and the electroplated through holes are in communication with the same copper layer conductor and the spacing between the electroplated through holes is 1 mm.

[0013] In some embodiments, the insulating film on the short end welding site of the FPC loop antenna is provided with a pad opening window with a length of 2 mm; the pad opening windows of adjacent short end welding sites are distributed in a staggered manner and the step difference is 0.5 mm.

[0014] In some embodiments, the FPC loop antenna is provided with a chip connection site and an independent capacitor welding site, the independent capacitor welding site is adjusted to a resonant frequency of 13.56±0.5 MHz by parallel capacitors; the chip connection site is provided with a pad opening window on the insulating film of the independent capacitor welding site.

[0015] The embodiments of the present disclosure also provide a manufacturing method of an NFC ring, characterized in that the NFC ring comprises the FPC loop antenna of any one of the above-mentioned embodiments, and the method comprises:

[0016] Bending the FPC loop antenna and embedding it into a groove in the ring;

[0017] Forming a loop by welding the FPC loop antenna to close the head and tail;

[0018] Setting a chip and a capacitor on the FPC loop antenna.

[0019] In some embodiments, the method is suitable for wafer form line binding of an antenna suitable for an RFID high-frequency chip and SMT patch of a DFN module; the wafer form line includes gold wire, alloy wire and aluminum wire.

[0020] In order to make the above-mentioned purposes, features and advantages of the present disclosure more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following will briefly introduce the drawings needed to be used in the embodiments. The drawings herein are incorporated into the specification and form a part of the specification, which show the embodiments consistent with the present disclosure, and are used to illustrate the technical solutions of the present disclosure together with the specification. It should be understood that the following drawings only show some embodiments of the present disclosure, and therefore should not be regarded as a limitation on the scope, and other related drawings can also be obtained by those skilled in the art without creative labor.

[0022] Figure 1 A schematic diagram of an FPC loop antenna provided by the embodiments of the present disclosure is shown.

[0023] Figure 2 A front view schematic diagram of an FPC loop antenna provided in an embodiment of this disclosure is shown;

[0024] Figure 3 A schematic diagram of the back of an FPC loop antenna provided in an embodiment of this disclosure is shown. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure 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 this disclosure, and not all of them. The components of the embodiments of this disclosure described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this disclosure provided in the accompanying drawings is not intended to limit the scope of the claimed disclosure, but merely represents selected embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0026] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0027] In this document, the term "and / or" merely describes a relationship, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" in this document means any combination of at least two of any one or more elements. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0028] Based on the above research, this disclosure provides an FPC loop antenna, utilizing...

[0029] like Figure 1 As shown, Figure 1 This is a schematic diagram of an FPC loop antenna provided in an embodiment of the present disclosure for use in an NFC ring, including a flexible substrate, an insulating film, and a copper layer conductor strip;

[0030] Copper conductive strips are distributed on both sides of the flexible substrate, and interlayer conductivity is achieved through electroplated vias; an insulating film covers both sides of the flexible substrate and also covers the copper conductive strips.

[0031] The FPC loop antenna is soldered and installed in the NFC ring.

[0032] The FPC loop antenna provided by the present disclosure is bent and assembled in a ring for later convenience, and a material with moderate bending flexibility and ensuring the best quality factor, self-resonant frequency and inductance of the antenna is selected. The copper layer conductive band is distributed on the front and back of the flexible substrate, and in order to meet different line requirements, four front copper layer conductive band distribution modes as shown in Figure 2 and two back copper layer conductive band distribution modes as shown in Figure 3 are provided for selection, a total of eight combinations.

[0033] In some embodiments, the length of the FPC loop antenna is 65.5 mm or 75.5 mm.

[0034] Since the main application scenario of the FPC loop antenna provided by the present disclosure is an NFC ring, the two sizes of 65.5 mm and 75.5 mm can be used for ring sizes of American standards 6#~13#.

[0035] In some embodiments, the copper layer conductive band has a thickness of 1.5 or 2.0 oz, and a surface plating thickness of 1~2μ"nickel gold layer.

[0036] Specifically, the copper layer conductive band can use electrolytic copper or rolled copper. The surface of the copper layer conductive band is plated with a nickel gold layer, which takes into account the double producibility of IC gold wire binding and SMT iron sheet, and the oxidation resistance of the copper layer conductive band.

[0037] In some embodiments, the single-sided line spacing of the copper layer conductive band is greater than 2 times the line width.

[0038] Specifically, by increasing the single-sided line spacing to be greater than twice the line width, the self-resonant frequency is greater than 45 MHz, so as to reduce the signal loss caused by the skin effect.

[0039] In some embodiments, the width of the FPC loop antenna is 5 mm.

[0040] Specifically, in order to adapt to different distribution modes of the copper layer conductive band, the width of the FPC loop antenna is designed with a 5 mm redundancy, which not only meets the width requirement of the NFC ring, but also ensures the overall line design of the FPC loop antenna.

[0041] In some embodiments, the FPC loop antenna is provided with a long end welding position and a short end welding position, and the long end welding position and the short end welding position are both provided with a plating through hole with a diameter of 0.15 mm. The plating through hole is in communication with the plating through hole of the same copper layer conductive band, and the plating through hole spacing is 1 mm.

[0042] The insulating film on the short end welding position of the FPC loop antenna is provided with a pad opening window with a length of 2 mm; the pad opening windows of the adjacent short end welding positions are distributed in a staggered manner and have a step difference of 0.5 mm.

[0043] Specifically, the electroplated through hole is not plugged, so that the soldering paste can be applied and heated for soldering in the later re-soldering process, thereby improving the production convenience. The soldering anti-fooling measures are distributed in a staggered manner on the pad window of the short end soldering position, so as to ensure that the FPC ring antenna head and tail overlap and are soldered, and the normal tin amount is used to avoid the occurrence of the antenna internal circuit short circuit.

[0044] In some embodiments, the FPC ring antenna is provided with a chip connection position and an independent capacitor soldering position, the independent capacitor soldering position is adjusted to a resonance frequency of 13.56±0.5MHz by parallel connection of capacitors, and the chip connection position is provided with a pad window together with an insulating film on the independent capacitor soldering position.

[0045] Specifically, in the conventional NFC ring, the parameters such as line width and number of turns need to be adjusted to ensure that the antennas of NFC rings with different radii all reach the standard frequency of 13.56±0.5MHz, while the FPC ring antenna provided by the present disclosure can realize antenna frequency adjustment by connecting capacitors of different specifications in parallel on the independent capacitor soldering position, so as to adapt to NFC rings with different finger sizes.

[0046] The embodiments of the present disclosure also provide a NFC ring manufacturing method, characterized in that the NFC ring comprises the FPC ring antenna in any one of the above-mentioned embodiments, and the method comprises the following steps:

[0047] Bending the FPC ring antenna and embedding it into the inner groove of the ring;

[0048] Closing the head and tail of the FPC ring antenna by soldering to form a ring shape;

[0049] Providing a chip and a capacitor on the FPC ring antenna.

[0050] In some embodiments, the method is suitable for wafer-shaped wire binding and DFN module SMT patch of an antenna suitable for an RFID high-frequency chip; the wafer-shaped wire includes a gold wire, an alloy wire and an aluminum wire.

[0051] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system and device described above can refer to the corresponding process in the foregoing method embodiment, and will not be repeated here. In several embodiments provided in the present disclosure, it should be understood that the disclosed system, device and method can be implemented in other ways. The above-described device embodiments are only schematic, for example, the division of the units is only a logical function division, and there can be another division in actual implementation, for example, a plurality of units or components can be combined or integrated into another system, or some features can be omitted or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some communication interfaces, devices or units, and can be electrical, mechanical or other forms.

[0052] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e. can be located in one place, or can be distributed on multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0053] Finally, it should be noted that: the above-described embodiments are only specific embodiments of the present disclosure, used to illustrate the technical solutions of the present disclosure, and not to limit them, the protection scope of the present disclosure is not limited thereto, although the present disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art within the technical range disclosed by the present disclosure can still modify or easily think of changes to the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to some technical features; and these modifications, changes or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure, and should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. An FPC loop antenna, characterized by, The application relates to a NFC ring, which comprises a flexible substrate, an insulating film and a copper layer conductor belt; the FPC ring antenna is provided with a long end welding position and a short end welding position; The copper layer conductor belt is distributed on the front and back surfaces of the flexible substrate and realizes interlayer conduction through electroplated through holes; the insulating film covers the front and back surfaces of the flexible substrate and covers the copper layer conductor belt; The FPC ring antenna is arranged in the NFC ring through head-to-tail welding; The length of the FPC ring antenna is 65.5mm or 75.5mm; The insulating film on the short end welding position of the FPC ring antenna is provided with a 2mm-length solder pad window; the solder pad windows of the adjacent short end welding positions are distributed in a staggered mode and have a 0.5mm step difference; The FPC ring antenna is provided with a chip connecting position and an independent capacitor welding position; the independent capacitor welding position is adjusted to a resonance frequency of 13.56+ / -0.5MHz through parallel capacitor adjustment; the insulating films on the chip connecting position and the independent capacitor welding position are both provided with solder pad windows.

2. The FPC loop antenna of claim 1, wherein, The thickness of the copper layer conductor belt is 1.5 or 2.0oz, and the surface is electroplated with a 1-2mil nickel-gold layer.

3. The FPC loop antenna of claim 1, wherein, The single-side line distance of the copper layer conductor belt is greater than 2 times the line width.

4. The FPC loop antenna of claim 1, wherein, The width of the FPC ring antenna is 5mm.

5. The FPC loop antenna of claim 1, wherein, The long end welding position and the short end welding position are both provided with electroplated through holes with a diameter of 0.15mm, the electroplated through holes are in communication, and the distance between the adjacent electroplated through holes on the copper layer conductor belt is 1mm.

6. A method of manufacturing an NFC ring, characterized by, The NFC ring comprises the FPC ring antenna according to any one of claims 1-5, and the method comprises the following steps: The FPC ring antenna is bent and embedded into a ring inner groove; The FPC ring antenna is closed at the head and tail through welding to form a ring shape; A chip and a capacitor are arranged on the FPC ring antenna.

7. The method of claim 6, wherein, The method is suitable for wafer-shaped wire binding of an RFID high-frequency chip and SMT patching of a DFN module; the wafer-shaped wire comprises a gold wire, an alloy wire and an aluminum wire.

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