JP2000105802A - Antenna magnetic core for noncontact data carrier, antenna for noncontact data carrier, and noncontact data carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a noncontact data carrier with high-sensitivity by reducing the stress applied to the antenna magnetic core being caused by the thermal shrinkage and setting shrinkage of the resin when an internal component is sealed with the resin. SOLUTION: A thin beltlike magnetic material such as a Fe-based, Co-based, or Ni-based amorphous magnetic alloy thin belt is wound in >=1 layer in conformity with the shape of the facing package of the noncontact data carrier to manufacture a nearly cylindrical magnetic core material 32. Liquid setting resin, such as urethane resin and silicone resin, which becomes elastic after hardened is stuck and hardened by dipping, coating, casting or the like on this magnetic core material 32 and a cushion layer 33 is formed surrounding the magnetic core material 32. The obtained antenna magnetic core 31 is inserted into a cylindrical bobbin which is equipped with a coil formed by winding a copper wire and is formed of polyamide resin to manufacture an antenna for transmission and reception.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic core for a non-contact data carrier, an antenna for a non-contact data carrier, and a non-contact data carrier. Specifically, I
A magnetic core used for a non-contact data carrier antenna which has a C chip as a main internal component and transmits / receives a signal to / from an external device in a non-contact manner, a non-contact data carrier antenna using the magnetic core, and a magnetic core The present invention relates to a non-contact data carrier using a core.

[0002]

2. Description of the Related Art A non-contact data carrier system is composed of a transponder which is called a non-contact data carrier and an interrogator connected to a host. , Induction electromagnetic field, microwave (radio wave)
It is characterized in that communication is performed in a non-contact manner via a transmission medium such as the one described above. This system possesses a transponder or attaches it to various articles, remotely reads information about the person or article possessed by the interrogator, and provides the host with the information to realize information processing about the person or article.

[0003] As an information transmission system of a non-contact data carrier system, an electromagnetic coupling system, an electromagnetic induction system, a microwave system, an optical communication system, and the like are generally known. Among these methods, in the electromagnetic coupling method, the electromagnetic induction method, and the microwave method, the energy of the transmission signal from the interrogator can be used as the driving power of the transponder. Since the transmission signal itself can be used as a drive source, there is no deterioration in response capability due to a decrease in battery output, as compared with other similar systems in which a drive source such as a battery needs to be built in the transponder. There is a great advantage that there is no limit on the use of the transponder due to battery life.

FIG. 5 shows the overall structure of a contactless data carrier system. As shown in FIG. 1, the contactless data carrier system includes an interrogator 10 and a transponder (contactless data carrier) 20.

The interrogator 10 includes a main controller 11 for controlling the entire interrogator 10, an interface 11 for controlling data input / output with the host device, and tag information received from the non-contact data carrier 20. Read / store
A storage unit 13 such as a writable RAM, for converting transmission information from a parallel signal to a serial signal;
The signal conversion unit 14 converts the received signal from the serial signal 0 into a parallel signal from a serial signal, and converts the transmission signal into, for example, ASK (Am
Plitude Shift Keying) method, FSK (Frequency Shif)
t Keying) modulating section 15 for modulating the signal for transmission
And a demodulation unit 16 for demodulating a received signal;
7 and a receiving antenna 18.

The transponder (contactless data carrier) 20
A main control unit 21 for controlling the entire non-contact data carrier 20, a storage unit 22 such as an EEPROM for storing tag information which does not require a power supply backup, converting transmission information from a digital signal to an analog signal, and an interrogator 10; A signal converter 23 for converting a received signal from an analog signal to a digital signal, a modulator 24 for modulating a transmission signal into a signal for transmission by an ASK method, an FSK method or the like, and a demodulator 25 for demodulating a received signal. , A transmission antenna 26, and a reception antenna 27.

The basic communication procedure of this contactless data carrier system is as follows. First, the interrogator 10
An interrogation signal for reading tag information from the non-contact data carrier 20 is issued. The contactless data carrier 20
When it enters the receivable range of the interrogation signal, it receives it,
The tag information stored in the storage unit 22 is transmitted as a response signal. The interrogator 10 receives and decodes this response signal and sends it to the host device as tag identification information.

The transponder 20 (contactless data carrier)
The antenna and circuit components for transmitting and receiving signals to and from the interrogator 10 are mainly configured, and in consideration of durability and environmental resistance, internal components such as transmission and reception antennas and circuit components are usually formed by a resin layer or the like. It has a hermetically sealed structure. As a transmitting / receiving antenna, a coil formed by a copper conductor is frequently used in terms of price and productivity, and as a circuit component, for example, a copper circuit pattern and a terminal portion are formed on the surface of an epoxy board, and an IC is formed on the coil. Generally, a chip is wire-bonded. Usually 1 outer diameter
The two end wires (conductor portions) of the coil formed by the copper wire of 0 to 200 μm are connected to the terminal portion of the circuit component by welding or soldering. As the resin material for hermetically sealing these internal components, thermoplastic resins such as vinyl chloride resin, polyethylene terephthalate resin, acrylonitrile-butadiene-styrene copolymer resin, or epoxy resin, phenol resin, silicone resin, etc. A thermosetting resin such as a thermosetting resin is used.

[0009]

By the way, in the non-contact data carrier system, it is necessary to reliably transmit and receive data regardless of the mounting position of the non-contact data carrier. Extending the communication distance is required, and higher sensitivity of the transmitting and receiving antennas is required. As a countermeasure, it has been known to use an amorphous magnetic material, ferrite, or the like as the antenna core to increase the transmission / reception sensitivity.

On the other hand, in the non-contact data carrier, it is necessary to cover the entire internal components such as antennas and circuit components with a sealing resin made of epoxy resin or the like in consideration of environmental resistance, impact resistance and the like. Consideration must be given to deterioration or breakage of the magnetic properties of the magnetic material for the magnetic core due to the sealing resin. In particular, when the internal component is sealed, there is a problem that a predetermined sensitivity cannot be obtained because external stress is applied to the internal component, and the antenna (magnetic core) is distorted or deformed.

The present invention has been made in view of such circumstances, and when an internal component is sealed with a resin, the antenna is protected from stress applied due to heat shrinkage or curing shrinkage of the sealing resin. It is an object of the present invention to obtain a highly sensitive non-contact data carrier by reducing the force applied to the core.

[0012]

SUMMARY OF THE INVENTION The object of the present invention is to reduce the stress due to the sealing resin by providing a buffer layer for stress relaxation around the antenna core for the above purpose.

[0013] The antenna core for a non-contact data carrier of the present invention is characterized in that an internal component having a circuit component including a storage element for storing information and an antenna for transmitting and receiving signals without contact with an external device is made of resin. In a sealed non-contact data carrier, an antenna core for a non-contact data carrier used for the antenna, wherein the non-contact data carrier antenna core includes a core material for a magnetic core, and a core material for the magnetic core. And a buffer layer for stress relaxation surrounding the buffer layer.

In the antenna magnetic core for a non-contact data carrier according to the present invention, the core material for the magnetic core is substantially cylindrical, and the inside of the cylinder is a buffer layer for stress relaxation. It is characterized by being filled.

An antenna for a non-contact data carrier according to the present invention is characterized in that an internal component having a circuit component including a storage element for storing information and an antenna for transmitting and receiving signals without contact with an external device is sealed with resin. A non-contact data carrier antenna used for a non-contact data carrier,
An antenna core for a non-contact data carrier according to claim 1 or 2, and a bobbin provided around the antenna core.
And a coil wound around the bobbin.

Further, in the non-contact data carrier of the present invention, an internal component having a circuit component including a storage element for storing information and an antenna for transmitting and receiving a signal without contact with an external device is sealed with a resin. In the above non-contact data carrier, the antenna is provided with an antenna core for a non-contact data carrier according to claim 1 or 2.

[0017]

FIG. 1 is a sectional view showing the structure of a non-contact data carrier according to the present invention, and FIG. 2 is a perspective view showing a magnetic core material of an antenna core used in the non-contact data carrier of FIG. 3 is a diagram showing an antenna core used for the non-contact data carrier of FIG. 1, wherein FIG. 3A is a plan view, FIG. 3B is a cross-sectional view, and FIG. It is a top view which shows a magnetic core.

The contactless data carrier 20 shown in FIG.
It comprises a circuit component 2, a transmitting / receiving antenna 3, and an outer case 1 for housing these internal components. The circuit component 2 is formed by forming a copper circuit pattern and a terminal portion on the surface of an epoxy board, for example, and soldering an IC chip thereto. The IC chip incorporates each functional circuit unit except for the transmitting / receiving antenna 3 in the configuration of the transponder shown in FIG.

The transmitting / receiving antenna 3 is configured by winding a coil 35 made of a conductive copper wire around a bobbin 34 in which the antenna core 31 is inserted.
Two end wires (conductor portions) of the coil 35 are connected to terminal portions of the circuit component 2 by welding or soldering.

As shown in FIG. 3 or FIG. 4, the antenna magnetic core 31 includes a magnetic core material 32 having magnetism and a buffer layer 33 surrounding the magnetic core material 32 for stress relaxation. .
Examples of the magnetic core material 32 include Fe-based, Co-based, and Ni-based.
Examples of the material include a ribbon-shaped magnetic material such as a ribbon made of an amorphous magnetic alloy or a ribbon made of a microcrystalline magnetic alloy. In the present invention, the core material 32 for the magnetic core is formed by winding the ribbon-shaped magnetic material into one or more layers according to the shape of the outer package of the non-contact data carrier 20, and as shown in FIG. With a circular or elliptical wound body,
That is, it is manufactured in a substantially cylindrical shape. Further, ferrite processed into the above-mentioned substantially cylindrical shape can also be used.

The buffer layer 33 is provided to reduce the stress applied to the antenna core 31 formed in the above shape when the internal components are sealed with resin. The buffer layer 33
Examples thereof include liquid curable resins having elasticity after curing, such as urethane resins, silicone resins, and epoxy resins. Those that do not affect the magnetic properties are preferably used. The liquid curable resin is dipped or applied to the magnetic core material 32 formed in the above shape,
It is attached by a method such as casting, and then cured. Thus, the buffer layer 33 for stress relaxation is formed so as to cover the periphery of the magnetic core material 32 as shown in FIG. At this time, the buffer layer 33 needs to be provided at least on the outer surface side of the magnetic core material 32, and is preferably provided on the back surface side of the magnetic core material 32 as shown in FIG.
Further, as shown in FIG. 4, the buffer layer 33 is
2, that is, the inside of a cylinder or an elliptical cylinder formed by the magnetic core material 32, and the inside of the magnetic core material 32 may be filled with the curable resin to further improve the antenna. The stress applied to the magnetic core 31 can be reduced.

The buffer layer 33 may be formed by winding an elastic body made of rubber, synthetic resin, or the like, for example, in the form of a film or tape, around the magnetic core 32, without using the curable resin. it can.

The transmitting / receiving antenna 3 comprises an antenna magnetic core 31 having the buffer layer 33 formed thereon, a bobbin 34 provided around the antenna magnetic core 31, and a coil 35 wound around the bobbin 34. Is done. The bobbin 34 functions as a support member that supports the coil 35 in a fixed shape. The bobbin 34 is formed into a substantially cylindrical shape or a substantially elliptic cylindrical shape by injection molding or the like from an insulating thermoplastic resin such as a polyester resin, a polyamide resin, and an ABS resin. The antenna core 31 is connected to the bobbin 34.
Inserted inside the tube. A coil 35 around which, for example, a copper conductor is wound is provided around a bobbin 34 used for the non-contact data carrier in FIG.

The transmission / reception antenna 3 and the circuit component 2 thus manufactured are housed in the outer case 1 and then sealed with the sealing resin 4. The outer case 1 is made of, for example, various plastic materials such as polycarbonate resin, polyester resin, polyamide resin, polyphenylene sulfide resin, and ABS resin having an insulating property.
It is manufactured in a cubic shape, a rectangular parallelepiped shape, a columnar shape or the like with one opening.

As the sealing resin 4 for sealing the internal parts,
For example, thermoplastic resins such as polystyrene, polyethylene, polypropylene, polyvinyl alcohol, polyurethane, phenolic resin, epoxy resin, acryl,
A thermosetting resin such as silicone can be used.
These sealing resins 4 are injected into the outer case 1, cooled and solidified, and the non-contact data carrier 20 is manufactured. When a photocurable resin is used, it is solidified by light irradiation.

By using the antenna core 31, the stress applied by the heat shrinkage and the cure shrinkage of the resin generated during the resin sealing is dispersed and absorbed by the buffer layer 33. As a result, the stress applied to the antenna core 31 is reduced, and the performance of the transmitting / receiving antenna 3 can be prevented from deteriorating.

In the above embodiment, the case where the coil 35 is wound around the bobbin 34 has been described.
In the present invention, it is also possible to form the coil 35 by directly winding a copper wire around the antenna core 31 provided with the buffer layer 33 around it without using the bobbin 34.

Further, there is no need to use the outer case 1, and the internal components are directly loaded into the mold, and the internal components are sealed by casting or transfer molding of an epoxy resin or the like, or by injection molding of a thermoplastic resin. Alternatively, the non-contact data carrier 20 can be manufactured.

[0029]

Next, an embodiment will be described.

(Example) A 10 mm wide Co-based amorphous magnetic alloy was wound so as to have a winding thickness of 0.05 mm and an outer diameter of 5.9 mm to form an antenna magnetic core. Next, the antenna magnetic core is immersed in a room-temperature-curable elastic urethane resin, taken out, and left for 24 hours to cure the urethane resin to form a buffer layer made of urethane resin on the outer and inner peripheral surfaces of the antenna magnetic core. did.

Next, this antenna magnetic core is set to a diameter of 0.05
A copper wire was wound into a cylindrical bobbin made of a polyamide resin having an outer diameter of 7.0 mm and an inner diameter of 6.0 mm wound with a copper wire to prepare a transmitting / receiving antenna.

Next, after connecting the end wire of the coil of the transmitting / receiving antenna to a circuit board to obtain an internal component, the internal component was inserted into a polycarbonate resin outer case having an inner diameter of 9 mm and an outer diameter of 10 mm. . Finally, an appropriate amount of liquid epoxy resin was injected into the outer case, and the epoxy resin was cured by heating at 80 ° C. in an oven, thereby producing a non-contact data carrier as an example.

Comparative Example A non-contact data carrier as a comparative example was obtained in the same steps except that the urethane treatment was not performed on the antenna core and the buffer layer was not formed.

(Comparative Test) The magnetic characteristics of the antenna core and the sensitivity of the non-contact data carrier before and after resin sealing were measured and evaluated for the non-contact data carriers of the above Examples and Comparative Examples. Specifically, the deterioration rate of the inductance at 125 kHz and 1 V and the communication distance before and after the injection of the epoxy resin were measured. Table 1 shows the results.

[0035]

[Table 1] (Test results) From Table 1, it can be seen from Table 1 that the provision of the buffer layer for stress relaxation on the antenna core reduces the deterioration of magnetic properties even after resin sealing, and that the antenna core provides a communication distance. Increased remarkably, and the effect of the present invention was confirmed.

[0036]

According to the present invention, since the buffer layer for stress relaxation is provided on the antenna core constituting the transmitting / receiving antenna, the stress applied to the antenna core due to the heat shrinkage or curing shrinkage caused by resin sealing is alleviated. can do. Therefore, it is possible to prevent the performance of the transmitting / receiving antenna from deteriorating and maintain the sensitivity of the antenna at high sensitivity. As a result, the reliability of data transmission / reception can be enhanced, and the communication distance between the transponder and the interrogator can be increased, thereby greatly contributing to the improvement of the characteristics of the contactless data carrier system.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of a contactless data carrier of the present invention;

FIG. 2 is a perspective view showing a magnetic core material of an antenna magnetic core used in the non-contact data carrier of FIG. 1;

3A and 3B are diagrams showing an antenna core used for the non-contact data carrier of FIG. 1, wherein FIG.
FIG. 2B is a cross-sectional view thereof.

FIG. 4 is a plan view showing another antenna core used for the non-contact data carrier in FIG. 1;

FIG. 5 is a block diagram showing a general overall configuration of a contactless data carrier system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Outer case 2 ... Circuit parts 3 ... Transmission / reception antenna 4 ... Sealing resin which seals internal parts 20 ... Non-contact data carrier 31 ... Antenna magnetic core 32 ... Core material for magnetic core 33 ... ... buffer layer for stress relaxation 34 ... bobbin 35 ... coil

Claims (4)

[Claims] 1. A non-contact data carrier in which an internal component including a circuit component including a storage element for storing information and an antenna for transmitting / receiving a signal without contact with an external device is sealed with a resin. An antenna core for a non-contact data carrier used for: a core material for a non-contact data carrier, and a buffer layer for stress relaxation surrounding the core material for the magnetic core. An antenna core for a non-contact data carrier, comprising: 2. The magnetic core material has a substantially cylindrical shape,
The antenna core for a non-contact data carrier according to claim 1, wherein the inside of the cylinder is filled with a buffer layer for stress relaxation. 3. A non-contact data carrier used for a non-contact data carrier in which an internal component including a circuit component including a storage element for storing information and an antenna for transmitting and receiving signals without contact with an external device is sealed with a resin. An antenna for a contact data carrier, comprising: a non-contact data carrier antenna core according to claim 1 or 2; and a bobbin provided around the antenna core.
An antenna for a non-contact data carrier, comprising: a coil wound around the bobbin. 4. A non-contact data carrier in which an internal component including a circuit component including a storage element for storing information and an antenna for transmitting and receiving signals without contact with an external device is sealed with a resin. A non-contact data carrier comprising a non-contact data carrier antenna core according to claim 1 or 2.