JP2020013315A - Booster antenna and dual IC card - Google Patents

Abstract

To provide a booster antenna having high stability of communication performance.SOLUTION: A booster antenna 100 comprises: an insulating substrate 101; a conductive main coil 112 formed one or more turns along the periphery of the substrate 101; and a conductive coupling coil 111 formed two or more turns inside a loop of the main coil 112, wherein a circuit on the substrate 101 is composed of only the main coil 112 and the coupling coil 111.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a booster antenna used in combination with an IC module and a dual IC card provided with the booster antenna.

  A dual IC card having a contact-type communication function and a non-contact-type communication function can be used for various purposes because a communication mode can be properly used according to a user's purpose. In recent years, a dual IC card has a card configuration in which an IC module having an antenna is joined by an insulating adhesive or the like, and power supply and communication can be performed by electromagnetic coupling with a booster antenna embedded in the card body. Have been. By configuring the dual IC card in this way, it is possible to prevent the electrical connection between the IC module and the card body from becoming unstable. This is because, when the IC module and the card body are directly connected by a conductive connecting member such as solder, the connecting member is damaged when the dual IC card is bent or the connecting member is deteriorated due to aging. This is because there is fear.

  The booster antenna described in Patent Literature 1 includes a coil antenna and a capacitive element. By the high-frequency magnetic field, a current flows in a parallel resonance circuit including a coil antenna and a capacitive element, and noncontact communication can be performed.

JP-A-2015-7899

The booster antenna described in Patent Literature 1 is excellent in that a communication distance of non-contact communication can be increased. On the other hand, if the resonance frequency of the booster antenna fluctuates due to variations in the capacitance of the capacitive element due to manufacturing tolerances, fluctuations in the stray capacitance due to the installation environment, or the like, the communication performance may become unstable.
Therefore, a booster antenna having a configuration suitable for an application in which stability is more important than communication distance is demanded.

An object of the present invention is to provide a booster antenna with high communication performance stability.
Another object of the present invention is to provide a dual IC card having high stability of a non-contact communication function.

  A first aspect of the present invention is directed to an insulating substrate, a conductive main coil formed one or more turns along a periphery of the substrate, and a conductive coupling coil formed inside a loop of the main coil. , And the circuit on the substrate is a booster antenna composed of only the main coil and the coupling coil.

  According to a second aspect of the present invention, a contact terminal for contacting a contact-type external device, a connection coil constituting a non-contact terminal by electromagnetic coupling, and an IC having a contact-type communication function and a non-contact-type communication function An IC module having a chip, a booster antenna of the present invention, and a plate-shaped card body accommodating the IC module and the booster antenna, wherein the connection coil and the coupling coil are at least partially formed in a plan view of the booster antenna. Are dual IC cards arranged so as to overlap.

The booster antenna of the present invention exhibits stable communication performance by being electromagnetically coupled to the IC module.
The dual IC card of the present invention exhibits a stable non-contact communication function.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the side which shows the dual IC card of one Embodiment of this invention typically. FIG. 3 is a plan view showing a booster antenna of the dual IC card. FIG. 3 is an equivalent circuit diagram for explaining the principle of the dual IC card. It is a top view showing the modification of the same booster antenna.

Hereinafter, a dual IC card according to an embodiment of the present invention will be described with reference to FIGS. The dual IC card 1 of the present embodiment is provided with the booster antenna of the present invention.
FIG. 1 is a schematic sectional view of the dual IC card 1. As shown in FIG. 1, the dual IC card 1 includes a plate-shaped card body 10 having a recess 11 formed therein, and an IC module 30 housed in the recess 11. A booster antenna 100 is embedded in the card body 10 and has a positional relationship that allows electromagnetic coupling with the IC module 30.

  FIG. 2 is a plan view of the booster antenna 100. FIG. The booster antenna 100 includes a substrate 101 and an antenna 110 provided on the substrate 101. The only conductive structure formed on the substrate 101 is a circuit including the antenna 110, and no capacitive element is formed.

The substrate 101 is formed in a rectangular shape in plan view using an insulating material such as PET (polyethylene terephthalate) or polyethylene naphthalate (PEN).
An accommodation hole 103 penetrating in the thickness direction of the substrate 101 is formed at a position near the short side 102 of the substrate 101. The accommodation hole 103 is formed in a rectangular shape having a side parallel to a short side or a long side of the substrate 101 in a plan view. The thickness of the substrate 101 is, for example, 15 to 50 μm (micrometer).

  The antenna 110 is connected to the coupling coil 111 for electromagnetic coupling with a connection coil 31 described later of the IC module 30 and is connected to the coupling coil 111 to perform non-contact communication with a non-contact external device such as a reader / writer. And a main coil 112. The coupling coil 111 is provided around the accommodation hole 103, as shown in FIG. The main coil 112 is formed in a rectangular shape along the periphery of the substrate 101 so as to surround the loop of the coupling coil 111.

  The coupling coil 111 is formed in a spiral shape extending in the surface direction of the substrate 101, and has a loop of two or more turns in the plan view of the booster antenna 100. Both ends of the coupling coil 111 extend toward the short side 102 of the substrate 101 and are connected to the main coil 112. Since the coupling coil 111 has two or more loops, at least one location has a three-dimensional intersection that overlaps in the thickness direction of the substrate 101. At the three-dimensional intersection, an insulator 111a on the thin film is arranged between the wires of the intersecting coupling coil 111, thereby preventing a short circuit between the wires.

As shown in FIG. 2, the main coil 112 is formed by one turn along the periphery of the substrate 102. The line width of the main coil 112 is wider than the line width of the coupling coil 111. The line widths of the coupling coil 111 and the main coil 112 can be appropriately set, and it is preferable that the imaginary part impedances at the set communication frequency be equalized by setting.
The main coil 112 may be formed with two or more turns, but one turn is most preferable in terms of performance.

The method of manufacturing the coupling coil 111 and the main coil 112 of the antenna 110 is not particularly limited, and can be formed by various methods. Examples of the manufacturing method include laser cutting and punching of a metal plate or a metal foil, etching of a metal foil or a metal layer, arrangement of metal wires, and the like. Punching is particularly suitable when the main coil 112 is formed wide. When the coupling coil is formed using the insulated metal wire, it is not necessary to separately arrange an insulator at the three-dimensional intersection, and the coil can be formed easily.
When the main coil and the coupling coil are formed of different materials, soldering, welding, pressure welding, or the like can be adopted as a method of connecting the two.

The card body 10 is made of a polyester material such as amorphous polyester, a vinyl chloride material such as PVC (polyvinyl chloride), a polycarbonate material, or an insulating material such as PET-G (polyethylene terephthalate copolymer). It is formed in a rectangular shape in plan view.
The recess 11 has a first storage portion 24 formed on the side surface of the card base 15 and a second storage portion 25 having a smaller diameter than the first storage portion 24 formed on the bottom surface of the first storage portion 24. And

As shown in FIG. 1, the IC module 30 includes a sheet-shaped module base 33, an IC chip 34 and a connection coil 31 provided on a first surface of the module base 33, and a second base of the module base 33. And a plurality of contact terminals (contact terminal portions) 35 provided on the surface of. The IC module 30 may further include an IC resin sealing portion 36.
The module base material 33 is formed in a rectangular shape in plan view using a material such as glass epoxy or PET. The thickness of the module substrate 33 is, for example, 50 to 200 μm.
As the IC chip 34, a known configuration having a contact-type communication function and a non-contact-type communication function can be used.
The connection coil 31 is formed in a spiral shape so as to surround the IC chip 34 and the IC resin sealing portion 36. The connection coil 31 is formed by patterning a copper foil or an aluminum foil by etching, and has a thickness of, for example, 5 to 50 μm. The connection coil 31 forms a non-contact terminal part by electromagnetically coupling with the coupling coil 111.

The plurality of contact terminals 35 are formed in a predetermined pattern by laminating, for example, a copper foil on the second surface of the module substrate 33. A portion of the copper foil exposed to the outside may be provided with a nickel layer having a thickness of 0.5 to 3 μm by plating, and a gold layer having a thickness of 0.01 to 0.3 μm is formed on the nickel film by plating. It may be provided.
Each contact terminal 35 is for contacting a contact type external device such as an automatic teller machine. The contact terminal 35 is connected to an element (not shown) built in the IC chip 34.
The IC chip 34 and the connection coil 31 are connected by a wire (not shown), and the IC chip 34, the connection coil 31 and the wire form a closed circuit.

  The resin sealing portion 36 can be formed of, for example, a known epoxy resin or the like. By providing the resin sealing portion 36, it is possible to protect the IC chip 34 and prevent disconnection of the wire.

  The connection coil 31 and the coupling coil 111 have a positional relationship in which at least a part thereof overlaps in a plan view of the dual IC card 1. The connection coil 31 and the coupling coil 111 are separated from each other in the thickness direction of the dual IC card 1. The separation distance can be appropriately set, but is preferably 0.4 mm or less.

Next, the operation of the dual IC card 1 configured as described above will be described. FIG. 3 is an equivalent circuit diagram for explaining the principle of the present dual IC card 1.
A high-frequency magnetic field is induced in the transmission / reception coil D12 by a high-frequency signal (not shown) generated in the transmission / reception circuit D11 of the reader / writer (non-contact type external device) D10. This high frequency magnetic field is radiated into space as magnetic energy.

At this time, when the dual IC card 1 is located in the high frequency magnetic field, a current flows through the booster antenna 100 of the dual IC card 1 by the high frequency magnetic field. The signal received by the main coil 112 is transmitted to the coupling coil 111. Thereafter, a signal is transmitted to the IC chip 34 by electromagnetic coupling between the coupling coil 111 and the connection coil 31.
At this time, in a plan view of the booster antenna 100, the current flow of the main coil 112 and the current flow of the coupling coil 111 are exactly opposite. For example, when the current flow of the main coil 112 is clockwise, the current flow of the coupling coil 111 is counterclockwise.

  Although not shown, when the dual IC card 1 performs power supply and communication with a contact type external device such as an automatic teller machine, terminals provided on the automatic teller machine are connected to the dual IC card 1. To the contact terminal 35. Then, power supply and communication are performed between the control unit of the automatic teller machine and the IC chip 34.

  According to the dual IC card 1 of the present embodiment, the antenna 110 of the booster antenna 100 is a circuit including only the coupling coil 111 and the main coil 112, and other conductive structures such as a capacitive element are provided on the circuit. Is not connected. Therefore, the resonance frequency does not fluctuate due to manufacturing variations of the capacitive element. As a result, there is no variation in impedance due to the installation environment and the like, the dual IC card 1 exhibits flat communication characteristics as a whole, and stable non-contact communication is possible.

  In the booster antenna 100, the main coil 112 and the coupling coil 111 are arranged such that the current flow of the main coil 112 and the current flow of the coupling coil 111 are opposite to each other in plan view of the booster antenna 100. Have been. Therefore, the coil impedance of the entire booster antenna 100 can be minimized. As a result, the power obtained by the booster antenna from the non-contact type external device is maximized, and the non-contact type communication performance of the dual IC card 1 can be optimized.

  As described above, one embodiment of the present invention has been described in detail with reference to the accompanying drawings. included.

For example, in the above-described embodiment, the mode in which the current flowing from the upper side in FIG. 2 flows outward from the center of the loop in the coupling coil has been described. In the booster antenna 100A of the modification shown in FIG. 4, the winding of the coupling coil 111A is opposite to that of FIG. As a result, the current flowing from the upper side in FIG. 4 flows from the outside of the loop toward the center.
Even in such an embodiment, the coil impedance of the entire booster antenna 100 can be minimized, and the same effect can be obtained.

DESCRIPTION OF SYMBOLS 1 Dual IC card 10 Card main body 30 IC module 31 Connection coil 34 IC chip 35 Contact terminal (contact terminal part)
100, 100A Booster antenna 101 Substrate 110 Antenna 111, 111A Coupling coil 112 Main coil

Claims (3)

An insulating substrate;
A conductive main coil formed one or more turns along the periphery of the substrate,
A conductive coupling coil formed two or more turns inside the loop of the main coil,
With
The circuit on the board is composed of only the main coil and the coupling coil,
Booster antenna. The main coil and the coupling coil are arranged such that current flows in opposite directions in plan view of the booster antenna.
The booster antenna according to claim 1. An IC module having a contact terminal portion for contacting a contact type external device, a connection coil forming a non-contact terminal portion by electromagnetic coupling, and an IC chip having a contact-type communication function and a non-contact type communication function;
A booster antenna according to claim 1,
A plate-shaped card body that houses the IC module and the booster antenna;
With
The connection coil and the coupling coil are arranged so that at least a part thereof overlaps in a plan view of the booster antenna.
Dual IC card.

Images