JP2001325571A - Noncontact communication type information carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a noncontact communication type information carrier which is inexpensive and has excellent communication characteristics. SOLUTION: The noncontact communication type information carrier is equipped with an IC element 2 which has an antenna coil 1 formed in one body, a booster coil 3 composed of a 1st coil 3a which is coupled with the antenna coil 1 mainly electromagnetically and a 2nd coil 3b which is electrically connected to the 1st coil 3a and coupled with an antenna coil that a reader writer is equipped with, and a base which carries those IC element 2 and booster coil 3; and the external diameter of the 1st coil is made larger than the external diameter of the antenna coil formed integrally with the IC element. The external diameter of the 1st coil 3a is preferably 1.3 to 7.5 times as large as the external diameter of the antenna coil 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact communication type information carrier having a booster coil and an IC element in which an antenna coil is integrally formed on a base.
The present invention relates to means for optimizing electromagnetic coupling between an antenna coil and a booster coil formed integrally with an element.

[0002]

2. Description of the Related Art Conventionally, an IC element and an antenna coil electrically connected to a terminal portion of the IC element are provided in a base having a predetermined shape, so that power is received from a reader / writer and the distance between the reader / writer and the reader / writer is reduced. 2. Description of the Related Art A non-contact information carrier that transmits and receives signals in a non-contact manner using electromagnetic waves is known. As this type of information carrier, there are a card shape, a coin shape, a button shape and the like depending on the outer shape.

Heretofore, as this type of information carrier, a carrier in which an antenna coil is formed in a pattern on a base, or a carrier in which an antenna coil composed of a winding is carried on a base, has been used. It does not require protection treatment of the connection point between the IC and the IC element and does not require moisture proof measures, and can be manufactured at low cost. Also, even if stress such as bending or torsion is applied to the base, the coil does not break and has excellent durability. There has been proposed a device in which an IC element in which an antenna coil is integrally formed with the IC element itself is mounted on a base.

When the antenna coil is formed integrally with the IC element, the winding diameter and the conductor width of the coil are smaller than when the antenna coil is patterned on the base or the antenna coil composed of a winding is carried on the base. Since the number of turns is naturally limited, it is difficult to increase the communication distance with the reader / writer, and the necessary communication distance may not be secured. Therefore, conventionally, as described in JP-A-8-532904 and the like,
A first coil having substantially the same size as the antenna coil integrally formed with the IC element, between the antenna coil formed integrally with the C element and the antenna coil provided in the reader / writer; A technique has been proposed in which a conductor loop, which is electrically connected to a base and has a second coil formed to have substantially the same dimensions, is disposed to enhance electromagnetic induction coupling between antenna coils.

[0005] In this specification, a conductor loop for enhancing electromagnetic coupling between antenna coils of this type is referred to as a "booster coil".

[0006]

If the antenna coil formed integrally with the IC element and the first coil constituting the booster coil are formed to have the same dimensions, the coupling coefficient between these coils theoretically becomes maximum, The communication characteristics between these coils can be optimized.

However, as a result of the experiment, the present inventors
Even if the antenna coil formed integrally with the IC element and the first coil forming the booster coil are formed to have the same dimensions,
The coupling coefficient between these two coils is not always the maximum,
We have learned that the communication characteristics between these two coils cannot be optimized. This is because the antenna coil formed integrally with the IC element is formed with high precision by optical means or the like, whereas the booster coil is usually formed by means such as printing or etching. ,
Even if the antenna coil formed integrally with the IC element and the first coil constituting the booster coil are formed to have the same dimensions,
Microscopically, it is considered that this is because a great difference occurs in the line width and the coil shape of both coils.

In the case of the booster coil, similarly to the antenna coil, if it is formed with high precision using optical means or the like, such a disadvantage does not occur, and the antenna coil and the first coil have the same dimensions as in theory. It is thought that the coupling coefficient between these two coils can be maximized and the communication characteristics between these two coils can be optimized by forming them.However, it is necessary to form the booster coils with high precision using optical means. Is because the cost of non-contact communication type information carrier increases,
There is no practicality at all.

Further, when the antenna coil formed integrally with the IC element and the first coil forming the booster coil are formed to have the same dimensions, the variation in the set interval between the antenna coil and the first coil and the displacement of the center can be prevented. Since the rate of change of the output voltage becomes large, there is a problem that the communication characteristics of the non-contact communication type information carrier as a product tend to vary. Also, in order to prevent such inconveniences, it is necessary to strictly control the mounting accuracy of the IC element with respect to the first coil. The cost of the formula information carrier increases.

The present invention has been made based on such knowledge, and an object thereof is to provide a non-contact communication type information carrier which is inexpensive and has good communication characteristics.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an IC element having an antenna coil formed integrally therewith, a first coil mainly electromagnetically coupled to the antenna coil, and a first coil. In a non-contact communication type information carrier comprising a booster coil comprising an antenna coil electrically connected to a second coil mainly electromagnetically coupled to an antenna coil provided in a reader / writer, and a base carrying the IC element and the booster coil. , The outer diameter of the first coil is determined by the IC
It is characterized in that the outer diameter is larger than the outer diameter of the antenna coil formed integrally with the element.

According to an experiment, the outer diameter of the first coil is equal to
Good results were obtained when the outer diameter of the antenna coil formed integrally with the element was 1.3 to 7.5 times.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A non-contact communication type information carrier according to an embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a sectional view of a non-contact communication type information carrier according to an embodiment, FIG. 2 is a perspective view of an IC element mounted on the non-contact communication type information carrier according to the embodiment, and FIG. FIG. 4 is a plan view of an IC element mounted on the non-contact communication type information carrier, and FIG. 4 is a pattern diagram of a booster coil mounted on the non-contact communication type information carrier according to the embodiment.

As shown in FIG. 1, a non-contact communication type information carrier of this embodiment comprises an IC element 2 on which an antenna coil 1 is integrally formed, an insulating substrate 4 on which a booster coil 3 is formed, And base 5 integrally supporting insulating substrate 4
Consists of

As shown in FIGS. 2 and 3, the IC element 2 has a rectangular spiral antenna coil 1 integrally formed on an input / output terminal 2a forming surface with an insulating layer 2b made of a polyimide resin film or the like interposed therebetween. Do it. The antenna coil 1 is
The photoresist method, that is, the photoresist layer is uniformly formed on the insulating layer forming surface of the IC element 2 (more practically, the completed wafer before being divided into individual IC elements) except for the input / output terminal forming portion. The photoresist layer is exposed and developed with a required coil pattern, and then a conductive metal material is sputtered or vacuum-deposited on the insulating layer 2b of the IC element 2 using the photoresist layer as a mask. Alternatively, the photoresist layer may be removed to form a coil pattern made of a conductive metal material on the surface on which the input / output terminals 4a are formed. In order to reduce the electric resistance of the coil pattern, a copper plating layer may be formed on the surface of the conductive metal film.

In the examples shown in FIGS. 2 and 3, the antenna coil 1 is formed in a rectangular spiral shape having a plurality of turns, but the number of turns and the planar shape of the antenna coil 1 are not limited thereto. Not something. That is, the number of turns can be any number of one or more turns, and the planar shape can be formed into an arbitrary shape such as a rectangle or a circle with oblique or arcuate chamfers at the corners. it can.

As shown in FIGS. 1 and 4, the booster coil 3 is composed of a first coil 3a having a small winding diameter and a second coil 3b having a large winding diameter, and is electrically connected to each other. . The first coil 3a is a coil mainly electromagnetically coupled to the antenna coil 1 integrally formed on the IC element 2, and has a planar shape and dimensions similar to those of the antenna coil 1 integrally formed on the IC element 2. It is formed. On the other hand, the second coil 3b is a coil mainly electromagnetically coupled to an antenna coil (see FIG. 5) provided in the reader / writer, and its planar shape and dimensions are formed as large as possible within the range of the base 5. . In the example of FIG.
Although the coil 3a and the second coil 3b are both formed in a rectangular spiral shape having a plurality of turns, the number of turns and the planar shape of each of the coils 3a and 3b are not limited thereto, and the above-described antenna coil is used. As in the case of 1, it can be formed into an arbitrary number of turns and a shape.

The booster coil 1 is formed by etching a conductive metal layer having a uniform thickness formed on one surface of the insulating substrate 4 to form a required coil pattern, or by forming a conductive film on one surface of the insulating substrate 4. It can be formed by a printing method of printing and forming a required coil pattern using ink.

The outer diameter Do2 of the first coil 3a is larger than the outer diameter Do1 of the antenna coil 1 formed integrally with the IC element 2, and is 1.3 to 7.0 times the outer diameter of the antenna coil 1.
It is formed five times. In the present specification, the outer diameter of the coil refers to the dimension between the conductive wires wound on the outermost periphery in the case of a coil having a plurality of turns, regardless of whether the planar shape is rectangular or circular. In the case of a one-turn coil, it refers to the dimension between the conductors constituting the coil. In addition, the inner diameter of the coil refers to the dimension between the conductors wound on the innermost circumference in the case of a coil having a plurality of turns, regardless of whether the planar shape is rectangular or circular. Means the dimension between the conductors constituting the coil.

The insulating substrate 4 is formed of an insulating material having required insulation and rigidity. As an insulating material suitable for forming the insulating substrate 4, for example, glass epoxy resin, polyimide resin, polyamide resin, polyethylene terephthalate resin (hereinafter abbreviated as PET).
Alternatively, a vinyl chloride resin or the like can be used.

As shown in FIG. 1, the IC element 2 has the antenna coil 1 directed toward the insulating substrate 4 and the antenna coil 1 and the first coil 3a concentric with each other. Is set to

The base 5 includes a cover sheet 6 and an adhesive layer 7. Among these, the cover sheet 6 can be formed of any sheet-like material such as paper or plastic sheet. However, since the cover sheet 6 is decomposed even if discarded and does not generate harmful substances such as dioxin even when incinerated,
Most preferably, it is formed of paper. When a plastic sheet is used as the cover sheet material, it is particularly preferable to use a chlorine-free plastic sheet such as PET because PET does not generate harmful substances such as dioxin even when incinerated. On the other hand, as the adhesive constituting the adhesive layer 7, any adhesive having a required hardness after curing can be used.
In order to enhance the protection effect of the antenna coil 3 and the IC element 4, it is particularly preferable to use a resin material having low hygroscopicity such as an epoxy resin.

Hereinafter, the effects of the present invention will be clarified by giving more specific examples of the non-contact communication type information carrier according to the present invention.

[0024]

<First Embodiment> An IC element 2 having a thickness of 550 μm has an outer diameter Do1 of 2.3 mm and a pitch p1 of 15 μm.
The antenna coil 1 having m turns and 46 turns was formed by a photoresist method. The conductor forming the antenna coil 1 was obtained by electrolytically plating copper on a coil pattern formed on the IC element 2 by sputtering, and the thickness was about 5 μm.

Glass epoxy plate 4 having a thickness of 100 μm
Has an outer diameter Do2 of 5.35 mm and an inner diameter Di2 of 0.6 m
m, the number of turns of the first coil 3a, and the outer diameter D in the vertical direction.
o3S is 20 mm, lateral outer diameter Do3L is 23 mm,
The booster coil 3 including the second coil 3b having a pitch p2 of 250 μm was formed by an etching method. The conductor serving as a source of the booster coil 3 has a thickness of 18 μm.
m of copper foil was used.

When the antenna coil 1 is directed toward the insulating substrate 4,
Further, the antenna coil 1 and the first coil 3a are concentric, and the IC element 2 is set on the side of the insulating substrate 4 on which the booster coil is formed. The IC element 2 and the insulating substrate 4 are coated on one side with an epoxy adhesive. Of the tag-shaped non-contact communication type information carrier A
I got

<Second Embodiment> Outer diameter Do of first coil 3a
2. A non-contact communication type information carrier B similar to the non-contact communication type information carrier A according to the first example was manufactured.

<Third Embodiment> Outer diameter Do of first coil 3a
A non-contact communication type information carrier C similar to the non-contact communication type information carrier A according to the first example was manufactured.

<Fourth Embodiment> Outer diameter Do of first coil 3a
A non-contact communication type information carrier D similar to the non-contact communication type information carrier A according to the first example was manufactured.

<First Comparative Example> Outer diameter Do of first coil 3a
2. A non-contact communication type information carrier E similar to the non-contact communication type information carrier A according to the first example was manufactured.

<Second Comparative Example> Outer diameter Do of first coil 3a
2 is 18 mm, and otherwise the same non-contact communication type information carrier F as the non-contact communication type information carrier A according to the first embodiment.
Was prepared.

Table 1 shows the outer diameter Do1 of the antenna coil 1 integrally formed with the IC element 2 and the first coil 3a constituting the booster coil 3 of the non-contact communication type information carrier according to each of the above embodiments and comparative examples. Ratio to the outer diameter Do2 (Do2 / Do)
1) is shown.

[0033]

[Table 1] Hereinafter, the results of the communication characteristic tests performed on the non-contact communication type information carriers A to F according to each of the above Examples and Comparative Examples will be described. FIG. 5 is a configuration diagram of a communication characteristic test apparatus,
It comprises an antenna coil 11 provided in a reader / writer, non-contact communication information carriers A to F, and a half-wave rectifier circuit 12 connected to the antenna coil 1 integrally formed with the IC element 2. The antenna coil 11 has a diameter of 40
The antenna coil 11 and the second coil 3b constituting the booster coil 3 are arranged concentrically, and the distance between these coils is fixed to 20 mm.

In the test, first, for the non-contact communication type information carriers A to F in which the set interval between the antenna coil 1 and the first coil 3a is adjusted to be constant, the antenna coil 11 has a carrier frequency of 13.56 MHz and a voltage Vant. Is 18.5V
, And measuring the rectified output voltage Vdd of the half-wave rectifier circuit 12. FIG. 6 shows the test results.

The horizontal axis in FIG. 6 is the outer diameter Do of the antenna coil 1.
1 and the outer diameter Do2 of the first coil 3a (Do2 / Do).
1), and the vertical axis in FIG. 6 is the rectified output voltage Vdd of the half-wave rectifier circuit 12. As is clear from this figure, the output voltage Vdd of each of the non-contact communication information carriers E and F according to the comparative example does not reach 11 V, whereas the non-contact communication information carriers A to D according to the embodiment. Are output voltage Vd
d is 11v or more, and the outer diameter D of the first coil 3a
It can be seen that when o2 is 1.3 to 7.5 times the outer diameter Do1 of the antenna coil 1, the communication characteristics of the non-contact communication type information carrier are improved.

When the outer diameter Do2 of the first coil 3a is larger than the outer diameter Do1 of the antenna coil 1, the output voltage V
dd is improved as the outer diameter Do2 increases.
This is probably because the number of turns of the coil 3a increases and the electromagnetic energy applied to the antenna coil 1 increases. On the other hand, when the outer diameter Do2 of the first coil 3a becomes excessively larger than the outer diameter Do1 of the antenna coil 1, the output voltage Vdd decreases because the inductance and the resistance value increase with the increase of the outer diameter Do2. However, it is considered that the electromagnetic energy applied to the antenna coil 1 is rather reduced.

Next, the antenna coil 1 and the first coil 3a
0.1mm, 0.2mm, 0.3mm,
For each of the non-contact communication type information carriers A to F adjusted to 0.4 mm, the carrier frequency of the antenna coil 11 is also 1
A signal having a voltage Vant of 18.5 V at 3.56 MHz was applied, and the rectified output voltage Vdd of the half-wave rectifier circuit 12 was measured. FIG. 7 shows the test results.

The horizontal axis in FIG. 7 is the set interval between the antenna coil 1 and the first coil 3a, and the vertical axis in FIG. 7 is the set interval between the antenna coil 1 and the first coil 3a adjusted to 0.1 mm. This is the output voltage value (Vdd / Vdd _0.1 ) normalized by the output voltage Vdd value (Vdd _0.1 ) obtained for the contactless communication information carrier. As is clear from this figure, the non-contact communication type according to the first comparative example in which the ratio (Do2 / Do1) of the outer diameter Do1 of the antenna coil 1 to the outer diameter Do2 of the first coil 3a is smaller than 1.3 times. The information carrier E shows that the standardized output voltage value sharply decreases as the set interval between the antenna coil 1 and the first coil 3a increases, while the outer diameter Do1 of the antenna coil 1 and the first The ratio of the coil 3a to the outer diameter Do2 (Do
The non-contact communication information carriers A to D according to the embodiments and the non-contact communication information carrier F according to the second comparative example, in which 2 / Do1) is greater than 1.3 times, have the standardized output voltage values. Is relatively stable.

This is the ratio of the outer diameter Do1 of the antenna coil 1 to the outer diameter Do2 of the first coil 3a (Do2 / Do1).
Is smaller, the antenna coil 1 and the first coil 3a
The output voltage Vdd sharply decreases due to the effect of the magnetic field that attenuates as the set interval increases, but the ratio of the outer diameter Do1 of the antenna coil 1 to the outer diameter Do2 of the first coil 3a ( When Do2 / Do1) is large, even if the magnetic field is attenuated as the set interval between the antenna coil 1 and the first coil 3a increases, the attenuation is compensated by increasing the diameter of the first coil 3a. Therefore, it is considered that the output voltage Vdd does not decrease, or even if the output voltage Vdd decreases, the decrease rate is reduced.
That is, the magnetic field H generated from the coil, the current I flowing through the coil, the radius R of the coil, and the distance d from the coil have a relationship expressed by the following equation (1). And the radius R of the coil is constant, the magnetic field H sharply decreases as the distance d from the coil increases.
However, the magnetic field spreads as the distance d from the coil increases. Therefore, by increasing the diameter of the first coil 3a, the decrease in the magnetic field is compensated and the large output voltage Vdd is obtained.
Is obtained.

[0040]

(Equation 1)

[0041]

As described above, in the non-contact communication type information carrier of the present invention, the outer diameter of the first coil constituting the booster coil is larger than the outer diameter of the antenna coil formed integrally with the IC element. Therefore, the electromagnetic energy radiated from the antenna coil provided in the reader / writer and relayed by the booster coil can be efficiently absorbed by the antenna coil formed integrally with the IC element, thereby improving the communication distance and improving the reader / writer. , Power consumption can be reduced. Further, since the outer diameter of the first coil constituting the booster coil is made larger than the outer diameter of the antenna coil formed integrally with the IC element, the set interval between these antenna coils and the first coil fluctuates. Even when the center position of the coil is displaced, it is possible to prevent or reduce a decrease in the output voltage, to reduce the variation in the communication characteristics of the non-contact communication type information carrier, and to make the IC element to the first coil smaller. Since it is not necessary to strictly control the mounting accuracy and it is possible to efficiently manufacture the non-contact communication type information carrier, the cost of the non-contact communication type information carrier can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a non-contact communication type information carrier according to an embodiment.

FIG. 2 is a perspective view of an IC element mounted on the non-contact communication type information carrier according to the embodiment.

FIG. 3 is a plan view of an IC element mounted on the non-contact communication type information carrier according to the embodiment.

FIG. 4 is a pattern diagram of a booster coil mounted on the non-contact communication type information carrier according to the embodiment.

FIG. 5 is a configuration diagram of a communication characteristic test device.

FIG. 6 is a graph showing a communication characteristic test result.

FIG. 7 is a graph showing a test result of a change in output voltage with respect to a set interval between an antenna coil formed integrally with an IC element and a first coil constituting a booster coil.

[Explanation of symbols]

 Reference Signs List 1 antenna coil 2 IC element 3 booster coil 3a first coil 3b second coil 4 insulating substrate 5 base 6 cover sheet 7 adhesive layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01Q 7/00 G06K 19/00 K (72) Inventor Ryuzo Fukao 1-88 Ushitora 1-chome Ushitora, Ibaraki-shi, Osaka F-term in Hitachi Maxell, Ltd. (reference) 2C005 MA19 MA29 MA40 NA09 PA01 PA15 PA19 RA30 TA22 5B035 AA00 BA05 BB09 CA01 CA23 5J046 AA03 AA09 AA19 AB11 PA07 QA02

Claims (2)

[Claims] 1. An IC element in which an antenna coil is integrally formed, a first coil mainly electromagnetically coupled to the antenna coil, and an antenna coil electrically connected to the first coil and provided in a reader / writer. In a non-contact communication type information carrier including a booster coil composed of a second coil that is electromagnetically coupled and a base that carries the IC element and the booster coil, the outside diameter of the first coil is set to the IC
A non-contact communication type information carrier, wherein the outer diameter of an antenna coil formed integrally with an element is larger than an outer diameter of the antenna coil. 2. The non-contact communication type information carrier according to claim 1, wherein an outer diameter of said first coil is 1.3 to 7.5 times an outer diameter of said antenna coil. Non-contact communication type information carrier.