JP2003281492A - Data carrier and method for adjusting tuning frequency of data carrier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prepare the coil of a data carrier in favor of sizes. <P>SOLUTION: Adjustment capacitors 13a and 13b (13c and 13d) for adjusting a capacity value corresponding to the inductance value of an antenna coil 12 operating tuned to a prescribed operation frequency are formed in the shape of a comb at a prescribed position on a board 14 to eliminate inconvenience that the inductance value of the antenna coil 12 is determined simply according to the capacity value of a capacitor prepared in an integrated circuit 11 provided at the data carrier, thereby the coil 12 of the data carrier can be prepared in favor of the sizes and can simply be adjusted corresponding to the operation frequency. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data carrier and a method of adjusting the tuning frequency of the data carrier, and more particularly,
It is suitable for use in determining the antenna coil of the data carrier in size priority.

[0002]

2. Description of the Related Art Conventionally, an RFID tag, a card (hereinafter collectively referred to as a data carrier) has a reader / reader.
An antenna coil is provided for receiving the information data transmitted from the writer device and transmitting the information data to the reader / writer device.

The antenna coil of the data carrier is
It may be printed on a board or printed on a card. In any case, the area of the antenna coil should be as large as possible in consideration of the communication distance.

[0004]

However, since the tuning capacitance is built in the ID tag IC for cost reduction, the inductance value of the antenna coil is a value corresponding to the capacitance of the capacitor peculiar to the ID tag IC. In most cases, it was simply decided so that

Since the number of turns of the antenna coil is selected by several turns, the size of the antenna coil is uniquely determined by the size and shape of the data carrier. Therefore, conventionally, the antenna coil cannot be formed in the maximum size, which is disadvantageous in communication distance.
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to enable a coil of a data carrier to be created with a size priority.

[0006]

A data carrier of the present invention is a data carrier having an antenna coil and a tuning capacitor that operate in synchronization with a predetermined operating frequency, and the data carrier corresponds to the inductance value of the antenna coil. The adjusting capacitor for adjusting the capacitance value of the tuning capacitor is formed in a comb shape at a predetermined position on the substrate. Another feature of the present invention is that the comb tooth-shaped adjusting capacitor is formed on both the front surface and the back surface of the substrate.

Further, a tuning frequency adjusting method of a data carrier of the present invention is a tuning frequency adjusting method of a data carrier having an antenna coil and a tuning capacitor which are tuned to operate at a predetermined operating frequency. The inductance of the antenna coil is adjusted by forming an adjustment capacitor for adjusting the capacitance value of the It is characterized in that the antenna coil is tuned to the operating frequency by obtaining a tuning capacitance value corresponding to the value. Another feature of the present invention is that the comb tooth-shaped adjusting capacitor is formed on both the front surface and the back surface of the substrate.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a data carrier and a tuning frequency adjusting method of the data carrier of the present invention will be described with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates a data carrier of this embodiment. This data carrier 10
An integrated circuit 11, a coil 12 and a capacitor 13 are arranged on the surface of a chip substrate 14.

The integrated circuit 11 includes a CPU, a RAM,
Various electric circuit components constituting the data carrier of the present embodiment are provided, including a computer system including a ROM. However, since their configurations and operations are not directly related to the description of the present invention, detailed description thereof will be omitted.

Regarding the coil 12, the coil that comes out of the integrated circuit 11 is shown as 12a, and the coil that returns to the integrated circuit 11 is shown as 12b. The coil 12a reaches the back surface 14b of the chip substrate 14 through the first through hole 15a. Then, the back surface 14b of the chip substrate is branched into one and the other, one of which is the coil 12
It is wound on the back surface 14b of the chip substrate as b, and the other is connected to the third comb tooth 13c.

The coil 12b extends from the rear surface 14b of the chip substrate 14 to the front surface 14a through the second through hole 15b, is wound a predetermined number of times on the front surface of the chip substrate 14, and then is wound into a third coil. Through hole 15c
Is branched into one and the other, and one coil 12b is connected to the integrated circuit 11. The other reaches the back surface 14b of the chip substrate through the third through hole 15c and is connected to the fourth comb tooth 13d on the back surface 14b of the chip substrate.

In the data carrier 10 of the present embodiment, the adjusting capacitor 13 is formed on the front surface and the back surface of the chip substrate 14 in a print pattern. The adjustment capacitor 13 is formed to supplement the shortage of the tuning capacitance formed in the integrated circuit 11 and adjust the tuning frequency. In the present embodiment, an example in which the adjusting capacitor 13 is formed in a comb shape is shown.

That is, as shown in FIG. 1, on the surface 14a of the chip substrate, the first comb teeth 13a are formed by connecting to the coil 12a, and the second comb teeth 13b are formed by connecting to the coil 12b. ing.

On the back surface 14b of the chip substrate,
The fourth comb tooth 13d is formed by connecting to the coil 12a, and the third comb tooth 13c is formed by connecting to the coil 12b. Then, the first comb teeth 13a and the third comb teeth 13
c, and the second comb teeth 13b and the fourth comb teeth 13d are formed so as to face each other on the front and back surfaces of the chip substrate 14.

As a result, in the present embodiment, the first comb tooth 13a and the second comb tooth 13b form a first adjusting capacitor, and the third comb tooth 13c and the fourth comb tooth 13c. The tooth 13d constitutes a second adjusting capacitor.

The first comb tooth 13a and the fourth comb tooth 13d are overlapped with each other, and the second comb tooth 13b and the third comb tooth 13c are overlapped with each other. The comb teeth 13a and the second comb teeth 13b can form a first adjustment capacitor, and the third comb teeth 13c and the fourth comb teeth 13d can form a second adjustment capacitor. The third comb tooth 13a and the fourth comb tooth 13d can form a third adjustment capacitor, and the second comb tooth 13b and the third comb tooth 13c can form a fourth adjustment capacitor. . The adjusting capacitor 13 may be configured by attaching a seal such as an aluminum foil.

As described above, in this embodiment, since the comb-shaped capacitor is formed as described above, the adjustment capacitor 13 can be formed in the print pattern. Further, since the adjustment capacitor 13 is configured by the print pattern, it is possible to easily make different capacitors such as increasing or decreasing the capacitance.

Therefore, according to the data carrier 10 of the present embodiment, the size of the antenna coil is equal to that of the integrated circuit 1.
It can be less restricted by the capacity of the capacitors formed in 1, and the coil 12 can be made with priority on the size of the data carrier.

Further, as shown in FIG. 5, if the comb-teeth pattern forming the adjusting capacitor 13 is cut by a predetermined number of comb-teeth by, for example, a laser, the tuning capacitance can be adjusted with high accuracy. It is possible to fine tune the tuning frequency of the data carrier 10.

As described above, in this embodiment, the first comb teeth 13a and the second comb teeth 13b are formed on the front surface 14a side of the chip substrate, and the third comb teeth 13a are formed on the back surface 14b side of the chip substrate. Comb tooth 13c and fourth comb tooth 13d
The adjustment capacitor 13 having a sufficiently large capacitance can be formed on the chip substrate 14 since the above is formed. As a result, the coil 12 can be formed with a size priority in accordance with the shape and size of the chip substrate 14.

In the above-described embodiment, when it is difficult to adjust the inductance value of the coil 12 with the adjusting capacitor 13, a seal made of metal foil is used as the front surface (back surface) of the data carrier 10. ) To increase the tuning frequency of the data carrier. In this case, the extent to which the tuning frequency becomes high can be adjusted by the size of the metal foil seal and the position where the metal foil seal is attached.

By doing so, the trouble of preparing a plurality of types of data carriers having different tuning frequencies in advance can be omitted, and the manufacturing and inventory control of the data carriers can be facilitated.

[0024]

As described above, according to the present invention,
Since the adjusting capacitor for adjusting the capacitance value corresponding to the inductance value of the antenna coil operating in synchronization with the predetermined operating frequency is formed in a comb shape at a predetermined position on the substrate, the inductance value of the antenna coil However, it is possible to create the antenna coil with priority on size without the inconvenience of being simply determined according to the capacitance value of the capacitor created in the integrated circuit provided in the data carrier. As a result, a data carrier having a long communication distance can be created.

According to another feature of the present invention, since the tuning frequency adjusting capacitor has a comb-teeth shape, it can be formed by a printed pattern, and the capacitor manufacturing process can be simplified. Moreover, since the capacitance value can be easily adjusted by cutting the comb teeth,
The process of tuning to the operating frequency can be easily performed by setting the optimum capacitance value according to the inductance value of the antenna coil.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention and showing a schematic configuration of a data carrier.

FIG. 2 is a rear view showing a schematic configuration of a data carrier.

FIG. 3 is a diagram showing details of the adjustment capacitor of the embodiment.

FIG. 4 is a perspective view showing a state in which adjustment capacitors are formed by being superposed on the front and back of a chip substrate.

FIG. 5 is a plan view of a data carrier in which an adjustment capacitor is cut by a predetermined number.

[Explanation of symbols]

10 data carriers 11 integrated circuits 12 coils 13 Adjustment capacitor 13a First comb tooth 13b Second comb tooth 13c Third comb tooth 13d fourth comb tooth 14 chip substrate

Claims (4)

[Claims] 1. A data carrier having an antenna coil and a tuning capacitor that operate in synchronization with a predetermined operating frequency, wherein the data carrier corresponds to the inductance value of the antenna coil.
A data carrier, wherein an adjusting capacitor for adjusting the capacitance value of the tuning capacitor is formed in a comb shape at a predetermined position on the substrate. 2. The data carrier according to claim 1, wherein the comb-shaped adjustment capacitors are formed on both the front surface and the back surface of the substrate. 3. A method for adjusting a tuning frequency of a data carrier having an antenna coil and a tuning capacitor which are tuned to operate at a predetermined operating frequency, the adjusting capacitor for adjusting a capacitance value of the tuning capacitor. A tuning capacitance value corresponding to the inductance value of the antenna coil is obtained by forming a comb tooth shape at a predetermined position on the substrate and cutting a predetermined number of teeth of the comb tooth shaped adjustment capacitor. A method for adjusting a tuning frequency of a data carrier, characterized in that the antenna coil is tuned to an operating frequency. 4. The method for adjusting the tuning frequency of a data carrier according to claim 3, wherein the comb-shaped adjusting capacitors are formed on both the front surface and the back surface of the substrate.