JP7024149B1 - RF tag - Google Patents

Abstract

The RF tag 1 is between a plate-shaped base material 11 formed of a dielectric, a loop-shaped upper surface conductive pattern 12 formed on the upper surface of the plate-shaped base material 11, and one end and the other end of the upper surface conductive pattern 12. A semiconductor device 15 having a circuit for transmitting and receiving data stored in a memory by radio waves, a lower surface conductive pattern 13 formed on the lower surface of a plate-shaped base material 11, a upper surface conductive pattern 12, and a lower surface conductive pattern. It has a connection conductive pattern 14 for connecting to 13. The width of the inner region of the loop formed by the upper surface conductive pattern 12 in the lateral direction is the width of the upper surface conductive pattern 12 in the lateral direction of the plate-shaped base material 11 and the longitudinal upper surface conductive pattern 12 of the plate-shaped base material 11. The shape is smaller than the width of.

Description

The present invention relates to RF tags.

Conventionally, RF tags that are supposed to be used while being attached to a conductor are known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2018-61275

In recent years, an automatic adjustment device having a function of automatically adjusting the capacitance according to the frequency of the radio wave received by the RF tag has been used. The RF tag described in Patent Document 1 is assumed to be used in a state of being attached to a conductor, and since it is composed of an inverted F-type antenna, the reactance is small and the area of the electrode is increased. The capacitance is increased. As a result, even if the device for automatic adjustment automatically adjusts the capacitance, there is a problem that the adjustable range of the frequency characteristic of the RF tag is narrow and the width of the frequency band in which the RF tag can transmit and receive data is small. ..

Therefore, the present invention has been made in view of these points, and an object thereof is to increase the width of the frequency band in which the RF tag can transmit and receive data.

The RF tag of the present invention is an RF tag capable of transmitting and receiving data by radio waves, and has a plate-shaped base material formed of a dielectric and a loop-shaped upper surface conductive pattern formed on the upper surface of the plate-shaped base material. A semiconductor device provided between one end and the other end of the upper surface conductive pattern, which stores the data and has a circuit for transmitting and receiving the data by radio waves, and formed on the lower surface of the plate-shaped base material. It has a formed lower surface conductive pattern and a connection conductive pattern connecting the upper surface conductive pattern and the lower surface conductive pattern, and the width in the lateral direction of the inner region of the loop formed by the upper surface conductive pattern is The shape is smaller than the width of the upper surface conductive pattern in the lateral direction of the plate-shaped base material and the width of the upper surface conductive pattern in the longitudinal direction of the plate-shaped base material.

The upper surface conductive pattern extends in a first region extending in the first direction, a second region extending parallel to the first region, and a second region orthogonal to the first direction, and one end thereof. A third region connected to the first region and the other end connected to the second region, and one end extending in parallel with the third region and one end to the side of the first region to which the third region is connected. The other end has a fourth region connected to the opposite side and the other end connects to the side to which the third region of the second region connects and the opposite side, and the first region has one end thereof and the third region. It has a first sub-region that is connected and the other end is connected to the semiconductor device, and a second sub-region that one end is connected to the fourth region and the other end is connected to the semiconductor device. The pattern is connected to the first sub-region at a position on a straight line in the first direction passing through the first sub-region, the semiconductor device, and the second sub-region, and extends in the first direction. It may have an existing area.

The connection conductive pattern is connected to a first direction region extending in the first direction from a position connected to the first sub region and a second direction region extending in the second direction. And may have.

The relationship between the area of the smallest quadrilateral including the upper surface conductive pattern and the area of the lower surface conductive pattern is the resonance frequency at which the intensity of the radio wave in the state where the RF tag is provided on the non-conductor is maximum and the said. The condition that the difference from the resonance frequency at which the strength of the radio wave is maximized when the RF tag is provided on the conductor is smaller than the frequency bandwidth required to secure the communication distance required for the RF tag. It may be a satisfying relationship.

Of the four sides of the smallest rectangle including the upper surface conductive pattern, the positions of the three sides other than the side to which the connected conductive pattern is connected are the positions of the connected conductive pattern among the four sides of the lower surface conductive pattern. A second side that corresponds to the position of three sides other than the connected side and is orthogonal to the first direction among the four sides of the rectangle in the first direction among the directions of the four sides of the rectangle. The difference between the position of the side in the direction and the position of the side in the second direction among the four sides of the lower surface conductive pattern is within ± 10% with respect to the length in the first direction, and the second side. The difference between the position of the side in the first direction among the four sides of the rectangle and the position of the side in the first direction among the four sides of the bottom surface conductive pattern in the direction is the length in the second direction. It may be within ± 10% of the total.

The upper surface conductive pattern extends in a first region extending in the first direction, a second region extending parallel to the first region, and a second region orthogonal to the first direction, and one end thereof. A third region connected to the first region and the other end connected to the second region, and one end extending in parallel with the third region and one end to the side of the first region to which the third region is connected. The other end has a fourth region connected to the opposite side and the other end connects to the side to which the third region in the second region connects and the other side, and the first region has one end thereof and the third region. It has a first sub-region that is connected and the other end is connected to the semiconductor device, and a second sub-region that one end is connected to the fourth region and the other end is connected to the semiconductor device. The width of the first region in the lateral direction of the region, the width of the second region in the lateral direction of the second region, the width of the third region in the lateral direction of the third region, and the fourth region. The ratio of the smallest width to the largest width of the width of the fourth region in the lateral direction of the above may be 2 or less.

The area of the upper surface conductive pattern may be 50% or more of the area of the lower surface conductive pattern.

According to the present invention, there is an effect that the width of the frequency band in which the RF tag can transmit and receive data can be increased.

It is a figure for demonstrating the outline of RF tag 1. FIG. It is a figure which shows the structure of RF tag 1. It is a figure for demonstrating the width of the upper surface conductive pattern 12. It is a figure for demonstrating the position of the connection conductive pattern 14. It is a figure for demonstrating the relationship between the shape of the upper surface conductive pattern 12 and the shape of the lower surface conductive pattern 13. It is a figure for demonstrating the structure of the connection conductive pattern 14. It is a figure which shows the other structural example of RF tag 1. It is a figure which shows the frequency characteristic of the plate-shaped base material 11 which concerns on this embodiment, and the comparative example.

[Overview of RF tag 1]
FIG. 1 is a diagram for explaining an outline of RF tag 1. The RF tag 1 is a device capable of transmitting and receiving data by radio waves. The RF tag 1 operates by the electric power generated by receiving the radio wave W1 transmitted from the reader / writer 3 in a state of being attached to the conductor 2. The RF tag 1 emits a radio wave W2 on which data stored in a built-in semiconductor device is superimposed.

The conductor 2 is an object through which an electric current can flow, and is, for example, a metal. The conductor 2 is not limited to metal, and may be wood or resin containing a substance capable of carrying an electric current. Further, the thickness of the RF tag 1 in the conductor 2 in the mounting direction is arbitrary, and may be a metal foil capable of passing an electric current.

Since the RF tag 1 and the conductor 2 are capacitively coupled to each other, the radio wave W2 generated by the RF tag 1 is also radiated through the conductor 2. As a result, even if the reader / writer 3 is present at a position where it is difficult to receive the radio wave W2 radiated by the RF tag 1, the reader / writer 3 receives the radio wave W2 via the conductor 2 and is stored in the RF tag 1. Data can be acquired.

FIG. 2 is a diagram showing the configuration of RF tag 1. FIG. 2A is a perspective view of the RF tag 1. FIG. 2B is a top view of the RF tag 1. FIG. 2C is a bottom view of the RF tag 1.

The RF tag 1 has a plate-shaped base material 11, an upper surface conductive pattern 12, a lower surface conductive pattern 13, a connection conductive pattern 14, and a semiconductor device 15.
The plate-shaped base material 11 is formed of a dielectric material. In the example shown in FIG. 2, the upper surface and the lower surface of the plate-shaped base material 11 are rectangular, but the shape of the upper surface and the lower surface of the plate-shaped base material 11 may be a polygon other than a rectangle, an oval shape, or an ellipse shape.

Further, the dielectric constituting the plate-shaped base material 11 may be composed of a plurality of types of members. In the plate-shaped base material 11, a sheet-shaped dielectric member provided with an upper surface conductive pattern 12, a lower surface conductive pattern 13, a connection conductive pattern 14, and a semiconductor device 15 is bonded to a plate-shaped dielectric. You may.

The upper surface conductive pattern 12 is a loop-shaped conductive pattern formed on the upper surface of the plate-shaped base material 11. The plate-shaped base material 11 is exposed inside the loop formed by the upper surface conductive pattern 12. A part of the loop formed by the upper surface conductive pattern 12 has a region in which the conductive pattern is not formed, and the semiconductor device 15 is provided in the region.

The lower surface conductive pattern 13 is a conductive pattern formed on the lower surface of the plate-shaped base material 11. The lower surface conductive pattern 13 is, for example, rectangular. The area of the lower surface conductive pattern 13 is larger than the area of the upper surface conductive pattern 12 and smaller than the area of the lower surface of the plate-shaped base material 11.

The connection conductive pattern 14 is a conductive pattern that connects the upper surface conductive pattern 12 and the lower surface conductive pattern 13. The connection conductive pattern 14 is configured to start from a part of the upper surface conductive pattern 12 and end at a part of the lower surface conductive pattern 13 via the side surface of the plate-shaped base material 11. In the example shown in FIG. 2, the connection conductive pattern 14 passes through one end of the upper surface conductive pattern 12, the semiconductor device 15, and the other end of the upper surface conductive pattern 12, and is a straight line parallel to the longitudinal direction of the plate-shaped base material 11. It is connected to the upper surface conductive pattern 12 at the upper position.

FIG. 4 is a diagram for explaining the position of the connection conductive pattern 14. FIG. 4A is a diagram showing a top surface conductive pattern 12 in a state where the semiconductor device 15 is not provided on the RF tag 1. In FIG. 4A, one end T1 and the other end T2 in the upper surface conductive pattern 12 are shown. A convex portion is formed on one end T1 and the other end T2 in the example shown in FIG. 4A, but the convex portion may not be formed on the one end T1 and the other end T2.

As shown by the thick line in FIG. 4B, the connection conductive pattern 14 passes through the rectangle including the semiconductor device 15 and forms the upper surface conductive pattern 12 at the position including the straight line L parallel to the longitudinal direction of the plate-shaped base material 11. It is connected. As long as the straight line L is included in the range where the connecting conductive pattern 14 and the upper surface conductive pattern 12 are connected, the width of the connecting conductive pattern 14 is larger than the width in the lateral direction of the region shown by the thick line. May be good and small. In FIG. 4B, a straight line L is drawn near the center of the region indicated by the thick line, but the position of the straight line L may be any position in the lateral direction of the region indicated by the thick line.

The semiconductor device 15 has a memory for storing data to be transmitted to the reader / writer 3. The semiconductor device 15 is provided between one end and the other end of the upper surface conductive pattern 12. Specifically, the semiconductor device 15 is provided between one end and the other end in the region extending in the longitudinal direction of the plate-shaped base material 11 in the upper surface conductive pattern 12.

Further, the semiconductor device 15 has a circuit for transmitting and receiving data stored in the memory by radio waves. The semiconductor device 15 has a plurality of built-in capacitors, and by switching one or more capacitors connected between one end and the other end of the upper surface conductive pattern 12, the space between one end and the other end of the upper surface conductive pattern 12 is switched. Capacitance can be adjusted. The semiconductor device 15 adjusts the capacitance so as to maximize the intensity of the received radio wave, for example.

Assuming that the reactance of the RF tag 1 is L and the capacitance is C, the resonance frequency f is represented by 1 / (2π√ (LC)). In order to change the resonance frequency as much as possible by adjusting the capacitance of the semiconductor device 15, it is desirable to make the capacitance of the RF tag as small as possible when the semiconductor device 15 is not provided.

However, since the frequency band of the radio wave that the RF tag 1 can communicate with the reader / writer 3 is set within a predetermined range, it is necessary to increase the reactance of the RF tag 1 in order to reduce the capacitance of the RF tag 1. There is. Therefore, the RF tag 1 has various features in order to increase the reactance. Hereinafter, the features of the RF tag 1 will be described.

[Characteristics of RF tag 1]
FIG. 3 is a diagram for explaining the width of the upper surface conductive pattern 12. The upper surface conductive pattern 12 has a first region (12a in FIG. 3) extending in the first direction and a second region (12b in FIG. 3) extending in parallel with the first region. Further, the upper surface conductive pattern 12 extends in a second direction orthogonal to the first direction, and has a third region (12c in FIG. 3) in which one end is connected to the first region and the other end is connected to the second region. Have. Further, the upper surface conductive pattern 12 extends parallel to the third region, one end of which is connected to the side opposite to the side to which the third region of the first region is connected, and the other end of which is connected to the third region of the second region. It has a fourth region (12d in FIG. 3) that connects to the opposite side. In other words, the upper surface conductive pattern 12 includes a first region and a second region parallel to the longitudinal direction of the plate-shaped substrate 11, and a third region and a fourth region parallel to the lateral direction of the plate-shaped substrate 11. Have.

The first region has a first sub-region 12a'in which one end is connected to the third region and the other end is connected to the semiconductor device 15, and one end is connected to the fourth region and the other end is connected to the semiconductor device 15. It has two subregions 12a'' and. The connection conductive pattern 14 is connected to the first sub-region at a position on a straight line in the first direction passing through the first sub-region, the semiconductor device 15, and the second sub-region, and extends in the first direction. Has an area.

The width of the inner region of the loop formed by the upper surface conductive pattern 12 in the lateral direction (E in FIG. 3) is the width of the upper surface conductive pattern 12 in the longitudinal direction of the plate-shaped substrate 11 (A and B in FIG. 3) and It is smaller than the width (C and D in FIG. 3) of the upper surface conductive pattern 12 in the lateral direction of the plate-shaped base material 11.

Since the top conductive pattern 12 has such a shape, the reactance of the top conductive pattern 12 becomes sufficiently large, so that the capacitance at the resonance frequency can be reduced. As a result, the capacitance of the semiconductor device 15 changes within the adjustable range of the capacitance of the semiconductor device 15, so that the resonance frequency can be adjusted in a wider frequency range than when the reactance of the upper surface conductive pattern 12 is small. As a result, the RF tag 1 can increase the width of the frequency band in which data can be transmitted / received as compared with the conventional RF tag. The frequency band is a frequency band capable of transmitting and receiving data at a distance required for the RF tag 1 to transmit and receive data to and from the reader / writer 3, for example, the width of the frequency band is 40 MHz. be.

The width of the first region 12a in the lateral direction of the first region 12a (A in FIG. 3), the width of the second region 12b in the lateral direction of the second region 12b (B in FIG. 3), and the short length of the third region 12c. The ratio of the smallest width to the largest width of the width of the third region 12c in the hand direction (C in FIG. 3) and the width of the fourth region 12d in the lateral direction of the fourth region 12d (D in FIG. 3). Is 2 or less. When the ratio of the smallest width to the largest width in the top surface conductive pattern 12 is 2 or less, it is possible to suppress an increase in capacitance due to a small current density in the large width region, and the top surface conductivity can be suppressed. The effective loop area of the pattern 12 becomes large.

FIG. 5 is a diagram for explaining the relationship between the shape of the upper surface conductive pattern 12 and the shape of the lower surface conductive pattern 13. FIG. 5A is a top view of the RF tag 1. The thick line in FIG. 5A shows the outline of the smallest quadrilateral including the upper surface conductive pattern 12. FIG. 5B is a bottom view of the RF tag 1.

Of the four sides of the smallest quadrilateral including the upper surface conductive pattern 12, the positions of the three sides (121a, 121b, 121c in FIG. 5A) other than the side to which the connecting conductive pattern 14 is connected are the lower surfaces. Of the four sides of the conductive pattern 13, the positions of the three sides (131a, 131b, 131c in FIG. 5B) other than the side to which the connecting conductive pattern 14 is connected correspond to the positions.

That is, the side 121a is parallel to the side 131a, and the distance from the side 111a to the side 121a in the longitudinal direction of the plate-shaped base material 11 is substantially equal to the distance from the side 111a to the side 131a. Further, the side 121b is parallel to the side 131b, and the distance from the side 111b to the side 121b in the lateral direction of the plate-shaped base material 11 is substantially equal to the distance from the side 111b to the side 131b. Further, the side 121c is parallel to the side 131c, and the distance from the side 111c to the side 121c in the longitudinal direction of the plate-shaped base material 11 is substantially equal to the distance from the side 111c to the side 131c.

By the way, since a capacitance is generated between the upper surface conductive pattern 12 and the lower surface conductive pattern 13, the provision of the lower surface conductive pattern 13 suppresses the fluctuation of the capacitance due to the influence of the conductor 2. However, if the upper surface conductive pattern 12 is attached to the conductor 2 in a state where it greatly protrudes from the lower surface conductive pattern 13, the resonance frequency fluctuates in the lower direction due to the capacitance generated between the protruding region and the conductor 2. Resulting in.

When the fluctuation amount of the resonance frequency is large, the RF tag 1 does not resonate at a frequency at which the communication distance required for the RF tag 1 can be secured depending on the characteristics of the conductor 2 provided with the RF tag 1, and the RF tag 1 is provided. There may be a problem that 1 cannot send and receive data within the communication distance. Therefore, the relationship between the area of the smallest quadrilateral including the upper surface conductive pattern 12 and the area of the lower surface conductive pattern 13 is that the resonance frequency f1 when the resonance frequency of the RF tag 1 is the highest and the resonance frequency of the RF tag 1 are the same. It is desirable that the difference from the resonance frequency f2 at the lowest level satisfies the condition that the difference is smaller than the frequency bandwidth required to secure the communication distance required for the RF tag 1.

As an example, the relationship between the area of the smallest quadrilateral including the upper surface conductive pattern 12 and the area of the lower surface conductive pattern 13 is the radio wave of the RF tag 1 in the state where the RF tag 1 is provided on the non-conductor (for example, resin). The difference between the resonance frequency f1 that maximizes the intensity and the resonance frequency f2 that maximizes the radio wave intensity of the RF tag 1 when the RF tag 1 is provided on a conductor (for example, metal) is obtained from the RF tag 1. It is desirable that the relationship satisfies the condition that the frequency bandwidth is smaller than the frequency bandwidth required to secure the communication distance. The relationship between the area of the smallest quadrilateral including the upper surface conductive pattern 12 and the area of the lower surface conductive pattern 13 is such that the required communication distance can be obtained regardless of the environment in which the RF tag 1 is used. Can be secured.

Specifically, the position of the side 121a in the longitudinal direction of the plate-shaped base material 11 among the four sides of the smallest quadrilateral including the upper surface conductive pattern 12 and the lower surface conductive pattern in the lateral direction of the plate-shaped base material 11. It is desirable that the difference from the position of the side 131a in the longitudinal direction of the plate-shaped base material 11 among the four sides of 13 is within ± 10% with respect to the length in the lateral direction of the plate-shaped base material 11. Similarly, it is desirable that the difference between the position of the side 121c and the position of the side 131c is within ± 10% with respect to the length of the plate-shaped base material 11 in the lateral direction. Further, in the longitudinal direction of the plate-shaped base material 11, the position of the side 121b in the lateral direction of the plate-shaped base material 11 among the four sides of the above-mentioned quadrilateral and the plate-shaped side of the four sides of the lower surface conductive pattern 13. It is desirable that the difference from the position of the side 131c in the lateral direction of the base material 11 is within ± 10% with respect to the length in the longitudinal direction of the plate-shaped base material 11.

Further, it is desirable that the area of the upper surface conductive pattern 12 is 50% or more of the area of the lower surface conductive pattern 13. When the area of the upper surface conductive pattern 12 is 50% or more with respect to the area of the lower surface conductive pattern 13 in this way, the reactance of the upper surface conductive pattern 12 can be sufficiently increased.

FIG. 6 is a diagram for explaining the configuration of the connection conductive pattern 14. FIG. 6A shows the same shape as the plate-shaped base material 11 shown in FIG. 2B, and FIG. 6B shows a modified example of the connection conductive pattern 14.

As shown in FIGS. 6A and 6B, the connection conductive pattern 14 has a first-direction region 14a extending in the first direction from a position connected to the first sub-region 12a'and a first-direction region. It is connected to 14a and has a second direction region 14b extending in the second direction. That is, the connection conductive pattern 14 is connected to the first direction region (14a in FIG. 6) extending in the longitudinal direction of the plate-shaped base material 11 from the position connected to the upper surface conductive pattern 12 and the longitudinal region, and is connected to the plate. It has a second direction region (14b or 14d in FIG. 6) extending in the lateral direction of the shaped substrate 11. As described above, the connection conductive pattern 14 has at least one bent portion in which the direction of the pattern changes, but the number of bent portions of the connected conductive pattern 14 is arbitrary.

As shown in FIG. 6A, the connection conductive pattern 14 may have two bent portions by further having a first direction region 14c connected to the second direction region 14b, and more than that. It may have a number of bends. By providing the bent portion in the connection conductive pattern 14 in this way, the reactance and the capacitance are different depending on the characteristics of the semiconductor device 15 mounted on the RF tag 1 by changing the length of the region before and after the bent portion. It is possible to easily design a kind of plate-shaped base material 11.

FIG. 7 is a diagram showing another configuration example of the RF tag 1. In the upper surface conductive pattern 12 of the RF tag 1 shown in FIG. 2, the semiconductor device 15 was provided at the center position of the first region 12a, but in the upper surface conductive pattern 12 of the RF tag 1 shown in FIG. 7, the first The semiconductor device 15 is provided at a position far from the connection conductive pattern 14 with respect to the central position of one region 12a. As described above, the position of the first region 12a in which the semiconductor device 15 is provided in the longitudinal direction is arbitrary.

[Comparison of frequency characteristics]
FIG. 8 is a diagram showing the frequency characteristics of the plate-shaped base material 11 and the comparative example according to the present embodiment. FIG. 8A shows the frequency characteristics of the plate-shaped base material 11 shown in FIG. 2, and FIG. 8B shows the frequency characteristics of the RF tag of the comparative example. The horizontal axis of FIG. 8 shows the frequency, and the vertical axis shows the readable distance.

The plate-shaped base material 11 corresponding to FIG. 8A had external dimensions of 10 mm × 51 mm × 4.3 mm, and the areas of the upper surface and the lower surface were 918 mm ² . Further, the capacitance (capacitance) of the plate-shaped base material 11 in the state where the semiconductor device 15 was not provided was 2.95 pF, and the inductance was 10.2 nH.

The capacitance of the semiconductor device 15 can be adjusted in the range of 0.16 pF, and the resonance frequency when the capacitance of the semiconductor device 15 is maximum is 24.7 MHz as compared with the resonance frequency when the capacitance of the semiconductor device 15 is minimum. It became low. That is, the adjustable range of the resonance frequency was 24.7 MHz. As a result, as shown in FIG. 8A, the bandwidth at which the readable distance is 10 m or more is about 40 MHz.

On the other hand, the RF tag of the comparative example corresponding to FIG. 8B had external dimensions of 14 mm × 55 mm × 2 mm and an area of the upper surface and the lower surface of 770 mm ² . The capacitance of the RF tag was 6.86 pF, and the inductance was 4.36 nH.

Since the RF tag of the comparative example has a smaller inductance and a larger capacitance than the plate-shaped base material 11 according to the present embodiment, the IC device capable of adjusting the capacitance can adjust the capacitance in the range of 0.18 pF. Regardless, the adjustable width of the resonance frequency was 12.0 MHz. As a result, as shown in FIG. 8B, the bandwidth at which the readable distance is 10 m or more is about 15 MHz.

As described above, the plate-shaped base material 11 according to the present embodiment has an inductance of 5 nH or more and a capacitance of 6 pF or less, so that the reader / writer 3 has an RF at a predetermined distance as compared with the RF tag of the comparative example. It was confirmed that the frequency band of the radio wave that can read the data from the tag can be increased.

[Effect of RF tag 1]
As described above, in the RF tag 1, the width of the inner region of the loop formed by the upper surface conductive pattern 12 in the lateral direction is the width of the upper surface conductive pattern 12 in the lateral direction of the plate-shaped base material 11 and the plate shape. The shape is smaller than the width of the upper surface conductive pattern 12 in the longitudinal direction of the base material 11. Since the RF tag 1 has the upper surface conductive pattern 12 having such a shape, the reactance of the RF tag 1 becomes large. Therefore, by adjusting the capacitance of the semiconductor device 15, it is possible to connect the RF tag 1 with the reader / writer 3. It becomes possible to increase the width of the frequency band in which data can be transmitted and received.

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes can be made within the scope of the gist thereof. be. For example, all or part of the device can be functionally or physically distributed / integrated in any unit. Also included in the embodiments of the present invention are new embodiments resulting from any combination of the plurality of embodiments. The effect of the new embodiment produced by the combination has the effect of the original embodiment together.

1 RF tag 2 Conductor 3 Reader / writer 11 Plate-shaped base material 12 Top conductive pattern 13 Bottom conductive pattern 14 Connection conductive pattern 15 Semiconductor device

Claims (7)

An RF tag that can send and receive data by radio waves
A plate-like base material formed of a dielectric and
A loop-shaped upper surface conductive pattern formed on the upper surface of the plate-shaped base material and
A semiconductor device provided between one end and the other end of the upper surface conductive pattern, which stores the data, and has a circuit for transmitting and receiving the data by radio waves.
The lower surface conductive pattern formed on the lower surface of the plate-shaped base material and
A connection conductive pattern connecting the upper surface conductive pattern and the lower surface conductive pattern,
Have and
The width of the inner region of the loop formed by the upper surface conductive pattern in the lateral direction is the width of the upper surface conductive pattern in the lateral direction of the plate-shaped substrate and the longitudinal width of the upper surface conductive pattern of the plate-shaped substrate. RF tag whose shape is smaller than the width of. The upper surface conductive pattern is
The first region extending in the first direction and
A second region extending parallel to the first region and
A third region extending in a second direction orthogonal to the first direction, one end connecting to the first region and the other end connecting to the second region.
It extends parallel to the third region, one end is connected to the side opposite to the side to which the third region is connected in the first region, and the other end is connected to the side to which the third region in the second region is connected. Has a fourth area, which connects to the opposite side,
The first region is
One end is connected to the third region, and the other end is connected to the semiconductor device.
A second sub-region in which one end is connected to the fourth region and the other end is connected to the semiconductor device.
Have,
The connection conductive pattern is connected to the first sub-region at a position on a straight line in the first direction passing through the first sub-region, the semiconductor device, and the second sub-region, and is connected to the first sub-region. Has an area that extends in the direction,
The RF tag according to claim 1. The connection conductive pattern is
A first-direction region extending in the first direction from a position connected to the first sub-region,
It is connected to the first direction region and has a second direction region extending in the second direction.
The RF tag according to claim 2. The relationship between the area of the smallest quadrilateral including the upper surface conductive pattern and the area of the lower surface conductive pattern is the resonance frequency at which the intensity of the radio wave in the state where the RF tag is provided on the non-conductor is maximum and the said. The condition that the difference from the resonance frequency at which the strength of the radio wave is maximized when the RF tag is provided on the conductor is smaller than the frequency bandwidth required to secure the communication distance required for the RF tag. It's a satisfying relationship,
The RF tag according to claim 1. Of the four sides of the smallest rectangle including the upper surface conductive pattern, the positions of the three sides other than the side to which the connected conductive pattern is connected are the positions of the connected conductive pattern among the four sides of the lower surface conductive pattern. It corresponds to the position of three sides other than the connected side,
The position of the side in the first direction among the directions of the four sides of the rectangle, the position of the side in the second direction orthogonal to the first direction among the four sides of the rectangle, and the position of the side of the four sides of the bottom surface conductive pattern. The difference from the position of the side in the second direction is within ± 10% with respect to the length in the first direction, and the side of the first direction out of the four sides of the rectangle in the second direction. The difference between the position and the position of the side in the first direction among the four sides of the lower surface conductive pattern is within ± 10% with respect to the length in the second direction.
The RF tag according to claim 4. The upper surface conductive pattern is
The first region extending in the first direction and
A second region extending parallel to the first region and
A third region extending in a second direction orthogonal to the first direction, one end connecting to the first region and the other end connecting to the second region.
It extends parallel to the third region, one end is connected to the side opposite to the side to which the third region is connected in the first region, and the other end is connected to the side to which the third region in the second region is connected. Has a fourth area, which connects to the opposite side,
The first region is
One end is connected to the third region, and the other end is connected to the semiconductor device.
A second sub-region in which one end is connected to the fourth region and the other end is connected to the semiconductor device.
Have,
The width of the first region in the lateral direction of the first region, the width of the second region in the lateral direction of the second region, the width of the third region in the lateral direction of the third region, and the said. The ratio of the smallest width to the largest width of the width of the fourth region in the lateral direction of the fourth region is 2 or less.
The RF tag according to claim 1. The area of the upper surface conductive pattern is 50% or more of the area of the lower surface conductive pattern.
The RF tag according to any one of claims 1 to 6.

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