A coupled module with patch capacitor and smart card using the same

Abstract

The application discloses a coupling module with a patch capacitor in the field of intelligent card design and manufacturing and an intelligent card using the module, the coupling module comprising an IC chip, a strip, a module coil on the strip and a patch capacitor, the capacitor being connected in parallel across the module coil electrically connected with the IC chip, the intelligent card comprising a card base and the coupling module embedded in a slot hole in an upper core material layer of the card base, the card base further comprising a lower core material layer, an inlay layer, an antenna coil arranged on the inlay layer, the antenna coil comprising a local coupling part and an amplification coupling part, the local coupling part being arranged below the slot hole, and the above scheme solves the problems of complex frequency modulation matching, many turns of the coupling antenna plane and short induction distance in the prior art, and achieves the technical effects of simplifying the frequency matching process, improving the induction distance, reducing the number of turns of the coil and miniaturizing the module.

Description

Technical Field

[0001] This application relates to the field of smart card design and manufacturing technology, specifically to a coupling module with a surface-mount capacitor and a smart card using the module. Background Technology

[0002] The mainstream processes for dual-interface composite cards currently include two main categories: physical connection processes and coupling processes. Physical connection processes mainly include soldering, non-conductive conductive pillar processes, conventional wire pick-and-spark soldering, and ACF processes. The first three processes achieve signal and power transmission through the physical connection between the card body inlay and the module antenna. The ACF process connects the module antenna to the card body inlay antenna through a non-conductive conductive film. Soldering and non-conductive conductive pillar processes are prone to antenna contact problems due to factors such as connection structure stability and assembly accuracy. Wire pick-and-spark soldering has high requirements for wire pick accuracy and soldering stability, requiring precise control of wire positioning and soldering pressure and temperature; otherwise, problems such as poor contact and antenna breakage may occur. The ACF process can also lead to poor module antenna contact problems in the later stages. The coupling process bonds the coupling module to the inlay antenna card with milled grooves using hot melt adhesive or other adhesives. Based on this, relying on the electromagnetic induction coupling effect, the module antenna and the card base inlay antenna form a closed magnetic field loop, thereby realizing wireless transmission of signals and electrical energy. Its principle is similar to NFC near-field coupling technology. Since the card's area and dimensions are relatively fixed, the inductance value can be changed by adjusting the number of turns, wire diameter, and spacing of the coil. In other words, the matching capacitance value also needs to be adjusted to keep the antenna frequency value fixed. Therefore, the frequency modulation of the coupling coil is significantly more difficult. Multiple compatibility tests are required for the winding parameters of the module coil and the card base inlay coil, such as the number of turns, wire diameter, and winding density. For example, patent documents with publication numbers WO2025120548A1 and CN106997482A both achieve this by using the geometry, number of turns, and wire diameter of the coil to generate capacitance. Moreover, the sensing distance of the coupling process is usually only 3-4cm, while the sensing distance of cards using conventional wire bonding processes can reach more than 4cm. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this application provides a coupling module with patch capacitors and a smart card using the module, in order to solve the problems of complex frequency modulation matching and short sensing distance caused by the large number of planar winding turns of the coupling antenna in existing technologies.

[0004] To achieve the above objectives, this application provides the following technical solution: A coupling module with a surface-mount capacitor has a front and a back side, including an IC chip, a strip, a module coil on the strip, and a capacitor. The module coil is wound from the outside to the inside along the edge of the back side of the strip, with two endpoints, an outer end and an inner end. The IC chip is located in the innermost region of the module coil on the back side of the strip and has two chip antenna solder points. The outer end endpoint returns to the inner pad outside the IC chip and the inner end in the innermost region of the module coil on the back side of the strip through an etched line on the front side of the strip. The two chip antenna solder points are electrically connected to the inner end and the inner pad of the module coil, respectively. The surface-mount capacitor is also electrically connected to the inner end and the inner pad on both sides, so that the capacitor is also mounted in parallel with the module coil in the innermost region of the module coil on the back side of the strip.

[0005] Preferably, the IC chip, inner pads, inner ends, and electrical connections on the back of the strip are also covered with an encapsulating adhesive protective layer.

[0006] Preferably, the front side of the strip has several electrically isolated contacts, which are connected to the respective contact pads of the IC chip, inner end, inner pad, capacitor, and other areas outside the electrical connection between them in the innermost ring of the module coil on the back side of the strip. The contact pads are electrically connected to the IC chip.

[0007] Preferably, the capacitor is a ceramic capacitor.

[0008] Based on the same inventive concept, this application is implemented through the following technical solutions: A smart card with a patch capacitor coupling module includes a card base and the aforementioned patch capacitor coupling module. The card base includes an upper core layer, a lower core layer, and an inlay layer of the same size between the upper and lower core layers. The upper core layer has a slot, and the patch capacitor coupling module is embedded in the slot. An antenna coil is disposed on the inlay layer. The antenna coil includes a local coupling part and an amplified coupling part. The local coupling part is disposed below the slot and is used to couple with the patch capacitor coupling module. The amplified coupling part is used to couple with a smart card reader / writer external to the smart card.

[0009] Preferably, the coupling module with surface-mount capacitor is a dual-interface integrated circuit card module, used to support contact communication and contactless communication.

[0010] Preferably, the local coupling portion and the amplification coupling portion of the antenna coil are wound using a single conductor.

[0011] Preferably, the amplification coupling part includes a first amplification coupling part and a second amplification coupling part, the first amplification coupling part is wound around the outer periphery of the cardi inlay layer, and the second amplification coupling part is located inside the first amplification coupling part.

[0012] Preferably, the local coupling portion is located inside the first amplified coupling portion.

[0013] Preferably, the local coupling portion is located outside the second amplified coupling portion.

[0014] This application proposes a coupling module with a surface-mount capacitor and a smart card using the module. By setting a surface-mount capacitor in parallel with the module coil on the coupling module strip and placing the surface-mount capacitor IC chip on the same side, precise frequency matching of the module can be achieved by flexibly selecting surface-mount capacitors of different capacitance values. This eliminates the need to adjust parameters such as coil geometry, number of turns, wire diameter, and winding density, and avoids modifying the antenna structure. It precisely modulates the module's operating frequency, meeting frequency adaptation requirements in different scenarios, significantly improving the flexibility and compatibility of the solution, and simplifying the modulation matching process for the desired resonant frequency of the smart card. Furthermore, the electrical connection between the IC chip and the antenna is achieved through electromagnetic coupling between the module coil on the IC chip side and the local coupling portion with the antenna coil in the card base, eliminating the need for physical wiring between the IC chip module and the antenna coil. This solution achieves highly reliable IC card connectivity. Simultaneously, it focuses on optimizing the performance of the coupling module in the coupling process card. By precisely matching the capacitor values ​​with the antenna and coil parameters, the energy coupling efficiency of the module can be optimized. In practical applications, the sensing distance of the coupled card is significantly improved, reaching over 4cm under normal operating conditions, meeting the needs of most short-range sensing scenarios such as contactless payment and identity recognition. Furthermore, in traditional coupling module designs, the number of turns in the winding coil is typically controlled to be more than ten to match frequency requirements. However, this solution, through capacitance compensation via parallel capacitors, can reduce the number of coil turns to less than ten. This reduction in turns not only lowers the requirements for tension control and arrangement accuracy during winding but also reduces the risk of wire breakage during winding, significantly improving production efficiency and yield, and adapting to the miniaturized layout requirements of the module. Attached Figure Description

[0015] Figure 1 This is an exploded perspective view of a smart card with a patch capacitive coupling module according to an embodiment of this application. Figure 2 This is a rear view of an embodiment of the coupling module with surface mount capacitors according to this application; Figure 3 This is a front view of an embodiment of the coupling module with surface mount capacitors according to this application; Figure 4 This is a schematic diagram of an embodiment of the card base inlay layer of this application; Among them, 1-coupled module with surface mount capacitor, 11-IC chip, 111-first solder joint of chip antenna, 112-second solder joint of chip antenna, 13-module coil, 131-outer end, 131a-etched line, 131b-inner pad, 132-inner end, 14-capacitor, 15-contact, 15b-contact pad, 16-encapsulation protective layer, 21-upper core material layer, 211-slot, 22-lower core material layer, 23-inlay layer, 3-antenna coil, 31-partial coupling part, 32-amplification coupling part, 32a-first amplification coupling part, 32b-second amplification coupling part. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0017] This embodiment provides a technical solution: a coupling module with a surface-mount capacitor, having a front and a back side, including an IC chip 11, a strip, a module coil 13 on the strip, and a capacitor 14. The module coil 13 is etched and wound along the edge of the back side of the strip from the outside to the inside, leaving two endpoints, an outer end 131 and an inner end 132. In this embodiment, the module coil 13 is roughly rectangular in shape. The IC chip 11 is located in the innermost region of the module coil 13 on the back side of the strip and has two chip antenna solder points. The IC chip 11 is packaged on the module using wire ball bonding. In the bonding mode, the outer end 131 returns to the innermost inner region of the module coil 13 on the back of the strip via the etched line 131a on the front side of the strip, outside the IC chip 11 and the inner pad 131b of the inner end 132. The two chip antenna solder points are electrically connected to the inner end 132 and the inner pad 131b of the module coil 13, respectively. In this embodiment, the first solder point 111 of the chip antenna is electrically connected to the inner pad 131b, and the second solder point 112 of the chip antenna is electrically connected to the inner end 132 of the module coil 13. The surface-mount capacitor 14 is also electrically connected to the inner end 132 and the inner pad 131b on both sides, so that the capacitor 14 is also mounted in parallel with the module coil 13 in the innermost inner region of the module coil 13 on the back of the strip. This allows the module coil 13, the capacitor 14, the built-in capacitor of the IC chip 11, the distributed capacitor of the coil, etc., to form an LC oscillation circuit, which satisfies the principle of parallel addition of capacitors. In the conventional mode without surface-mount capacitors, the LC oscillation of the module only uses the built-in capacitors of the chip and the distributed capacitance of the coil, without surface-mount capacitors for compensation.

[0018] To better protect the back side of the strip, the IC chip 11, inner pad 131b, inner end 132 and the electrical connection between them on the back side of the strip are covered with an encapsulating adhesive protective layer 16, which can be made of materials such as epoxy resin.

[0019] To enhance support for contact communication, the front side of the strip, i.e., the metal surface of the module, is positioned with several electrically isolated contacts 15. These contacts 15 are connected to contact pads 15b in areas other than the innermost region of the module coil 13 on the back side of the strip, including the IC chip 11, inner end 132, inner pad 131b, capacitor 14, and areas where they are electrically connected. The contact pads 15b are electrically connected to the IC chip 11. In this embodiment, the contacts 15 are C1: VCC, C2: RST, C3: CLK, C5: GND, and C7: IO. Refer to the electrical connection details of the IC chip module on the strip disclosed in patent document CN108764436B. Therefore, the coupling module 1 with surface-mount capacitors is a dual-interface integrated circuit card module used to support both contact and contactless communication.

[0020] In this embodiment, capacitor 14 is a commonly used surface-mount ceramic capacitor. The SMT process facilitates mounting and component selection. For example, the industry-standard 0201 package can be selected. The module frequency can be accurately matched by flexibly selecting surface-mount capacitors with different capacitance values.

[0021] This application discloses a smart card or identification card with a patch capacitor coupling module, comprising a card base and a coupling module 1 with a patch capacitor. The card base includes an upper core layer 21, a lower core layer 22, and an inlay layer 23 of the same size between the upper and lower core layers 21 and 22. The upper core layer 21 has a slot 211 milled into it. The coupling module 1 with the patch capacitor is embedded in the slot 211. An antenna coil 3 is disposed on the inlay layer 23. The antenna coil 3 includes a local coupling part 31 and an amplifying coupling part 32. The local coupling part 31 is disposed below the slot 211 and is used to couple with the module coil 13 of the coupling module 1 with the patch capacitor. The amplifying coupling part 32 is used to couple with a smart card reader or writer device outside the smart card, such as a card reader. The antenna coil 3 of this application is used to realize energy and signal interaction with external devices. The antenna coil 3 can receive electromagnetic information and energy from outside the smart card and can also transmit electromagnetic information and energy to outside the smart card. Therefore, the module coil 13 of this application is configured to electromagnetically couple with the partial coupling portion 31 of the antenna coil 3 of the card base inlay layer 23 when the coupling module 1 with patch capacitor is assembled into the slot 211 of the card base. The antenna coil 3 of the card base inlay layer 23 can be wound with materials such as copper wire, and the winding wire can form a non-closed loop. Since the coupling module 1 with patch capacitor uses patch capacitor, the card base winding and frequency modulation are relatively simple.

[0022] On the card base, in this embodiment, the local coupling portion 31 and the amplification coupling portion 32 of the antenna coil 3 are wound with a single wire. The amplification coupling portion 32 has a first amplification coupling portion 32a and a second amplification coupling portion 32b. The first amplification coupling portion 32a is wound along the outer periphery of the card base inlay layer 23, and the second amplification coupling portion 32b is located inside the first amplification coupling portion 32a. The shape of the first amplification coupling portion 32a can be adapted to the shape of the smart card, such as a rectangle. The shape of the second amplification coupling portion 32b is not limited. The local coupling portion 31 can be located inside or outside the first amplification coupling portion 32a. In this embodiment, it is designed to be inside the first amplification coupling portion 32a and outside the second amplification coupling portion 32b.

[0023] In the description of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A coupling module with surface-mount capacitors, having a front side and a back side, characterized in that: The components include an IC chip (11), a strip, a module coil (13) on the strip, and a capacitor (14). The module coil (13) is wound from the outside to the inside along the back edge of the strip and has two endpoints, an outer end (131) and an inner end (132). The IC chip (11) is located in the innermost region of the module coil (13) on the back of the strip and has two chip antenna solder points. The outer end (131) returns to the module coil (13) on the back of the strip through the etched line (131a) on the front of the strip. In the innermost inner region, the IC chip (11) and the inner pad (131b) are located outside the inner end (132). The two chip antenna solder points are electrically connected to the inner end (132) and the inner pad (131b) of the module coil (13), respectively. The surface-mount capacitor (14) is also electrically connected to the inner end (132) and the inner pad (131b) on both sides, so that the capacitor (14) is also mounted on the innermost inner region of the module coil (13) on the back of the strip and connected in parallel with the module coil (13).

2. The coupling module with surface-mount capacitor according to claim 1, characterized in that: The IC chip (11), inner pad (131b), inner end (132) and electrical connection between the back of the strip are also covered with an encapsulating adhesive protective layer (16).

3. The coupling module with surface-mount capacitor according to claim 2, characterized in that: The front of the strip has several electrically isolated contacts (15), which are connected to the contact pads (15b) of the innermost inner region of the module coil (13) on the back of the strip, the IC chip (11), the inner end (132), the inner pad (131b), the capacitor (14), and the area outside the electrical connection between them. The contact pads (15b) are electrically connected to the IC chip (11).

4. The coupling module with surface-mount capacitor according to claim 1, characterized in that: The capacitor (14) is a ceramic capacitor.

5. A smart card with a patch capacitor coupling module, comprising a card base, characterized in that: It also includes the coupling module (1) with patch capacitor as described in claim 1. The card base includes an upper core material layer (21), a lower core material layer (22) of the same size, and an inlay layer (23) between the upper core material layer (21) and the lower core material layer (22). The upper core material layer (21) is provided with a slot (211). The coupling module (1) with patch capacitor is embedded in the slot (211). An antenna coil (3) is provided on the inlay layer (23). The antenna coil (3) includes a local coupling part (31) and an amplification coupling part (32). The local coupling part (31) is located below the slot (211) and is used to couple with the coupling module (1) with patch capacitor. The amplification coupling part (32) is used to couple with a smart card reader / writer outside the smart card.

6. The smart card with a patch capacitor coupling module according to claim 5, characterized in that: The coupling module (1) with patch capacitor is a dual-interface integrated circuit card module used to support contact communication and contactless communication.

7. The smart card with a patch capacitor coupling module according to claim 6, characterized in that: The local coupling part (31) and the amplification coupling part (32) of the antenna coil (3) are wound with a single conductor.

8. The smart card with a patch capacitor coupling module according to claim 5 or 7, characterized in that: The amplification coupling part (32) includes a first amplification coupling part (32a) and a second amplification coupling part (32b). The first amplification coupling part (32a) is wound around the outer periphery of the cardi inlay layer (23), and the second amplification coupling part (32b) is located inside the first amplification coupling part (32a).

9. The smart card with a surface-mount capacitor coupling module according to claim 8, characterized in that: The local coupling part (31) is inside the first amplified coupling part (32a).

10. The smart card with a surface-mount capacitor coupling module according to claim 8, characterized in that: The local coupling part (31) is outside the second amplified coupling part (32b).

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