JP2024050450A - Wireless apparatus and wireless communication system including the same - Google Patents

Abstract

To provide a wireless apparatus that contains a coiled antenna, and has reduced power loss and high power efficiency, and a wireless communication system including the wireless apparatus.SOLUTION: A wireless apparatus includes a base material, a coiled antenna, and a circuit. The antenna has an intersection where at least a portion thereof intersects at the top and bottom through an insulating film, and the line width of the antenna at the intersection is thinner than the line width of at least a portion of the antenna at a portion other than the intersection.SELECTED DRAWING: Figure 1

Description

The present invention relates to a wireless device and a wireless communication system including the same.

Systems that use radio waves to communicate and supply power are known. For example, there are contactless IC cards that use 13.56 MHz radio signals for wireless communication (see, for example, Patent Document 1), and systems that enable wireless power supply by magnetically coupling a power supply coil antenna and a power receiving coil antenna (see, for example, Patent Document 2).

Patent document 3 also shows a loop antenna having a loop conductive wiring and a jumper wire, in which the loop conductive wiring and the jumper wire cross at a bent portion of the loop conductive wiring via an insulating layer having a first through hole and a second through hole, thereby reducing the effects of noise.

JP 2014-220016 A WO2017/126419 WO2019/175995

The antenna shown in Patent Document 3 has improved symmetry in the antenna shape, which makes it possible to reduce the effects of noise. However, at the intersections of the loop conductive wiring and the jumper wire, capacitance is formed through the insulating layer at each intersection, which is an issue that causes power loss.

The present invention has been made in consideration of the above, and aims to provide a wireless device including a coil-shaped antenna that reduces power loss and has high power efficiency, and a wireless communication system including the same.

In order to solve the above-mentioned problems, the present invention has the following configuration.
[1] A wireless device comprising a substrate, a coil-shaped antenna, and a circuit, wherein at least a portion of the antenna has an intersection where the antenna intersects with the top and bottom via an insulating film, and the line width of the antenna at the intersection is narrower than the line width of at least a portion of the antenna other than the intersection.
[2] The wireless device according to [1], wherein the insulating film has a thickness of 1 μm or less.
[3] A wireless device according to [1] or [2], wherein the line width of the antenna in the non-intersecting portion of the antenna is greater than 100 μm and smaller than 2000 μm.
[4] The wireless device according to any one of [1] to [3], wherein the line width of the antenna at the intersection is greater than 10 μm and smaller than 500 μm.
[5] The wireless device according to any one of [1] to [4], wherein at least a portion of the circuit section is disposed inside the antenna section which is formed in a coil shape.
[6] The wireless device according to any one of [1] to [5], wherein the thickness of the antenna at the intersection is different between the top and bottom.
[7] A wireless device according to any one of [1] to [6], wherein the materials of the antennas at the intersection are different above and below.
[8] The wireless device according to any one of [1] to [7], wherein at least one of the insulating films included in the elements in the circuit is shared with the insulating film at the intersection.
[9] A wireless device according to any one of [1] to [8], which is used for anti-counterfeiting purposes.
[10] A wireless device according to any one of [1] to [9], further comprising a sensing unit connected to the circuit.
[11] The wireless device according to [10], wherein the sensing unit is disposed outside the antenna unit which is formed in a coil shape.
[12] A wireless communication system including a wireless device according to any one of [9] to [11], and a wireless communication unit capable of supplying power to the wireless device and wirelessly communicating with the wireless device.
[13] A moisture detection system including a wireless device according to [10] or [11], and a wireless communication device capable of supplying power to the wireless device and communicating wirelessly with the wireless device, wherein the sensing unit detects moisture.
[14] An opening detection system including a wireless device according to [10] or [11], and a wireless communication unit capable of supplying power to the wireless device and communicating wirelessly with the wireless device, wherein the sensing unit detects whether or not a packaging material has been opened.
[15] A temperature detection system including a wireless device according to [10] or [11] and a wireless communication device capable of supplying power to the wireless device and communicating wirelessly with the wireless device, wherein the sensing unit detects temperature.

The present invention provides a wireless device that includes a coil-shaped antenna and has reduced power loss and high power efficiency, as well as a wireless communication system that includes the same.

FIG. 1 is a schematic plan view showing a wireless device according to a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing a wireless device according to the first embodiment of the present invention. FIG. 3 is a schematic block diagram showing a circuit according to the first embodiment of the present invention. FIG. 4 is a schematic plan view showing a wireless device according to a second embodiment of the present invention. FIG. 5 is a schematic cross-sectional view showing a wireless device according to a second embodiment of the present invention. FIG. 6 is a schematic cross-sectional view showing a part of a circuit according to the second embodiment of the present invention. FIG. 7 is a schematic plan view showing a wireless device according to a third embodiment of the present invention. FIG. 8 is a schematic block diagram showing a circuit according to a third embodiment of the present invention. FIG. 9 is a schematic diagram showing a wireless communication system according to a fourth embodiment of the present invention. FIG. 10 is a schematic diagram showing a moisture detection system according to a fifth embodiment of the present invention.

Below, a description will be given of a form for carrying out the present invention (hereinafter, referred to as an "embodiment") with reference to the attached drawings. However, the present invention is not limited to the following embodiment, and can be modified in various ways depending on the purpose and application. Furthermore, each element described in each embodiment can also be applied to any other embodiment as long as it does not impair the effect of the present invention.

(Embodiment 1)
Fig. 1 is a schematic plan view showing the configuration of a wireless device according to a first embodiment of the present invention, and Fig. 2 is a schematic cross-sectional view taken along the XX' plane of Fig. 1. The wireless device 100 shown in Figs. 1 and 2 includes a substrate 10, a coil-shaped antenna 20, and a circuit 30.

As long as the substrate 10 has electrical insulation properties and is configured to allow the formation of the antenna 20 and the circuit 30, there are no particular limitations on its material composition or manufacturing method. The material of the substrate 10 is preferably, for example, glass or resin, and the substrate 10 is preferably in the form of a plate or film. From the viewpoint of application to various uses, the substrate 10 is preferably a flexible film, specific examples of which include, for example, a PET (polyethylene terephthalate) film, a PP (polypropylene) film, a PVC (polyvinyl chloride) film, and laminates thereof. From the viewpoint of flexibility, the substrate 10 is preferably as thin as possible, for example, a thickness of 10 μm to 1 mm is preferable.

The antenna 20 has at least one spiral (hereinafter referred to as "loop") shape, and has a loop portion 201 made of a conductor formed on the same plane, and a jumper portion 202 made of a conductor formed on a plane different from the plane on which the loop portion 201 exists. In the following description, the antenna in the loop portion 201 is called a loop line, and the antenna in the jumper portion 202 is called a jumper line. The loop portion 201 and the jumper portion 202 are arranged via an insulating film 250 that has electrical insulation properties. That is, the antenna 20 has intersections (hereinafter simply referred to as "intersections") 204A and 204B where the loop line and the jumper line intersect above and below via the insulating film 250. The loop portion 201 and the jumper portion 202 are electrically connected by contacts 203A and 203B that connect them.

Figure 1 shows an example in which the number of turns in the loop portion is three, but the number of turns is not limited as long as the desired characteristics can be obtained with at least one turn. However, from the viewpoint of use as a coil antenna, the number of turns is preferably greater, and preferably three or more turns. On the other hand, from the viewpoint that too many turns will increase the area of the loop portion and increase costs, it is preferable that the number of turns be seven or less.

There are no restrictions on the materials constituting the loop wire, jumper wire, and contacts 203A, 203B as long as they are conductive, but materials with high conductivity are preferable from the viewpoint of use as a coil antenna. Such materials include metals such as gold, copper, silver, nickel, tin, bismuth, lead, zinc, palladium, platinum, aluminum, tungsten, and molybdenum, inorganic substances containing at least one element selected from the group consisting of these metals and carbon, mixtures of the above inorganic substances and organic substances, organic substances having conductivity, etc. These are used alone or in combination of two or more types of materials. The materials constituting the loop wire, jumper wire, and contacts 203A, 203B may be the same or different from each other.

The loop wire, jumper wire, and contacts 203A, 203B may each be a single layer made of the above materials, or a laminate in which multiple layers made of the above materials are stacked, or a laminate in which one or more layers made of the above materials and one or more layers made of other materials are stacked.

It is preferable to select materials suitable for the electrical characteristics required and the formation of the loop wire and the jumper wire. For example, since the length of the loop wire as an antenna is relatively long, it is preferable to use a material with high conductivity from the viewpoint of improving the electrical characteristics. In addition, since it can be formed directly on the flat substrate 10, it does not matter if the workability is somewhat low. On the other hand, although the jumper wire is relatively short, it is formed after the loop portion and the insulating film 250 have already been formed, so it is formed on a material with unevenness. Therefore, it is preferable to use a material with excellent workability for the jumper wire. In this way, it is preferable that the material of the antenna at the intersection is different between the loop wire and the jumper wire depending on the required characteristics.

The circuit 30 is electrically connected to the coil-shaped antenna 20, and as long as it can obtain the desired characteristics, its function, material, composition, and formation method are not particularly important. It is preferable that the circuit 30 includes a power circuit for transmitting AC power generated by the antenna 20 due to an external magnetic field or electromagnetic field to each functional element and each functional circuit in the circuit 30.

The circuit 30 and the antenna 20 may be connected at two points as shown in the first embodiment, or may be connected at three or more points. In the first embodiment, the jumper wire passes through the loop wire once via the contact portion 203B before being connected to the circuit, but the jumper wire may be directly connected to the circuit 30.

Figure 3 is a block diagram showing the vicinity of the circuit 30 connected to the antenna 20 in the wireless device 100 shown in Figure 1. The antenna 20 is connected to a power circuit, and the power circuit converts the AC power generated by the antenna 20 into DC power suitable for the functional circuit, and the functional circuit realizes the desired function. Note that although only one functional circuit is shown in Figure 3, multiple circuits or a combination of various elements can be used as the functional circuit to obtain the desired function or characteristics. In addition, the power circuit and the functional circuit are connected by two lines, but this connection is a schematic representation of a power supply and a reference potential (ground potential), and the number of lines and each role are not particularly limited. For example, the power circuit may output multiple power supply voltages, and its configuration and function are not particularly limited as long as it converts the AC power generated by the antenna 20 into DC power.

From the standpoint of area efficiency and ease of connection to the antenna, it is preferable that the circuit 30 be placed inside the antenna 20, which is formed in a coil shape.

The insulating film 250 is not particularly limited in terms of its material, composition, film structure, etc., as long as electrical insulation can be obtained. From the viewpoint of ensuring electrical insulation between the loop portion and the jumper portion, the volume resistivity of the insulating film 250 is preferably high, for example, 1×10 ⁵ Ω·m or more, and more preferably 1×10 ⁷ Ω·m or more. From the viewpoint of reliability, it is preferable that the time until dielectric breakdown occurs is long. In order to make the entire wireless device 100 as thin as possible and to provide flexibility, it is preferable that the insulating film 250 is thin, and is preferably thinner than the substrate 10. The thickness of the insulating film 250 is preferably 10 μm or less, and more preferably 1 μm or less.

In the present embodiment 1, the line widths of the loop wire and the jumper wire at the intersections 204A and 204B are both narrower than the line widths of the respective wires at the portions where they do not intersect. With this configuration, the overlapping area of the loop wire and the jumper wire that overlap via the insulating film 250 at the intersection of the loop portion 201 and the jumper portion 202 is reduced, so that the electrical capacitance formed at the intersection is reduced, and power loss is reduced.

In the first embodiment, an example is shown in which the loop wire and the jumper wire are both thin at the intersections 204A and 204B, but as long as the desired characteristics are obtained, the width of only one of the loop wire and the jumper wire may be thin.

In addition, in this embodiment 1, the area where the loop wire and jumper wire have a narrower line width (hereinafter referred to as the "narrow width area") is an area that extends slightly beyond the intersection, including not only the area directly above the intersection but also the areas before and after it. This is done to take into account manufacturing variations, and the amount of expansion can be freely set by the manufacturer as appropriate. Of course, the narrow width area may be limited to the area directly above the intersection. From the perspective of reducing the resistance component of the antenna, it is preferable not to expand the narrow width area too much.

In addition, in this embodiment 1, the line width of the loop line and jumper line at the intersection is thinner than the line width of each line in all of the parts where they do not intersect, but even if there are parts other than the intersection where the line width is thinner than the intersection, there is no particular problem as long as the object of the present invention is achieved.

The line width of the loop wires and jumper wires at the intersections is set to a desired value depending on the electrical capacitance formed at the intersections, the resistance due to the current flowing through the intersections, the life span of electromigration, the Q value (Quality Factor) as a coil antenna, etc. Specifically, the line width of the loop wires and jumper wires at the intersections is preferably greater than 10 μm and less than 500 μm, and more preferably greater than 30 μm and less than 100 μm. In addition, the electrical capacitance formed at the intersections is preferably 10 picofarads (pF) or less per intersection, and more preferably 2 pF or less.

The line width of the loop wires and jumper wires other than at the intersections is preferably thicker because this reduces electrical resistance. On the other hand, if the line width is too thick, the area required as an antenna increases, leading to increased costs. For these reasons, the line width of the loop wires and jumper wires other than at the intersections is preferably greater than 100 μm and less than 2000 μm, and more preferably greater than 300 μm and less than 700 μm.

Regarding the relationship between the line width of the loop wire and the jumper wire, an example is shown in Figure 1 where the jumper wire is thicker than the loop wire, but this relationship is not limited to this. In other words, the loop wire may be thicker than the jumper wire, or they may be the same width.

It is preferable that the thickness of the loop wire is thinner than that of the jumper wire in order to improve the flexibility of the wireless device. When the wireless device 100 is used for wearable applications, for example, it is important to improve its flexibility. By reducing the thickness of the loop wiring in the loop section 201, which occupies a large area in the wireless device 100, flexibility is improved. On the other hand, the jumper section 202 occupies a small area in the wireless device 100 and contributes little to the flexibility of the wireless device 100, so by maintaining a certain thickness, adverse effects on electrical characteristics can be suppressed. In other words, it is preferable that the antenna thickness at the intersection formed by the jumper wire and the loop wire is different between the loop wire and the jumper wire, and it is particularly preferable that the thickness of the loop wire is thinner than the thickness of the jumper wire.

When the wireless device 100 is used in an application where flexibility is not a consideration, it is preferable that the loop portion 201 and the jumper portion 202 have high conductivity from the viewpoint of electrical characteristics, and therefore it is preferable that the loop wire and the jumper wire are thick.

The wireless device according to the first embodiment described above has an intersection where the loop wire and jumper wire, which are part of the antenna, intersect above and below via an insulating film, and the line width of the loop wire and the jumper wire at the intersection is narrower than their line widths at parts other than the intersection, thereby reducing power loss and providing high power efficiency.

In the first embodiment, a wireless device formed only by the circuit 30 and the antenna 20 is shown, but a capacitance C may be added to form an LC resonant circuit with the antenna 20, and multiple coil-shaped antennas may be arranged.

(Embodiment 2)
Fig. 4 is a schematic plan view showing the configuration of a wireless device according to embodiment 2 of the present invention, and Fig. 5 is a schematic cross-sectional view taken along the YY' plane in Fig. 4. Wireless device 101 shown in Figs. 4 and 5 includes substrate 11, coil-shaped antenna 21, and circuit 31.

The configuration of the wireless device 101 according to the second embodiment is the same as that of the wireless device 100 according to the first embodiment, except that the insulating film 251 is formed over substantially the entire surface of the substrate 11. In this configuration, at least one of the insulating films included in the elements in the circuit 31 is the insulating film 251. In other words, at least one of the insulating films included in the elements in the circuit is shared with the insulating film at the intersection.

Figure 6 is a schematic cross-sectional view of a circuit 31 in which at least one of the functional elements is a thin-film transistor. Note that while Figure 6 shows only one functional element that constitutes the circuit 31, the circuit 31 realizes an electrical function through a collection of multiple functional elements, and may include multiple thin-film transistors or functional elements other than thin-film transistors.

The thin-film transistor 220 shown in FIG. 6 is composed of a gate electrode 221, a gate insulating layer made of an insulating film 251, source and drain electrodes 222 made of the same material as the jumper wire, and a semiconductor layer 300 on a substrate 11 common to the wireless device 101.

The loop wire and the gate electrode 221 may be made of the same or different materials, and the jumper wire and the source and drain electrodes 222 may be made of the same or different materials.

This thin-film transistor 220 is an example in which the semiconductor 300 is present on the insulating film 251 between the source electrode and the drain electrode, but the configuration is not particularly limited as long as the desired characteristics of the thin-film transistor are obtained. Other configurations of thin-film transistors include, for example, a so-called top-contact type thin-film transistor structure in which the semiconductor 300 extends to the bottom of the source and drain electrodes 222, and a so-called bottom-contact type thin-film transistor structure in which the semiconductor 300 extends to the top of the source and drain electrodes 222.

The material of the semiconductor layer 300 is not particularly limited, but it is preferable to include organic semiconductors, carbon nanotubes, graphene, etc., either alone or as a composite. In particular, from the viewpoint of electrical properties, it is preferable to include semiconducting carbon nanotubes, and it is particularly preferable that the ratio of semiconducting carbon nanotubes is high relative to metallic carbon nanotubes. Specifically, it is preferable that 80% or more of the carbon nanotubes are semiconducting, and more preferably 90% or more are semiconducting. Furthermore, it is even more preferable that the semiconductor layer 300 includes a carbon nanotube composite having a conjugated polymer attached to at least a part of the surface. Examples of such carbon nanotube composites include those disclosed in International Publication No. 2009/139339.

The wireless device according to the second embodiment described above has excellent manufacturing costs because the insulating film used for the circuit 31 and the antenna 21 is common.

In particular, the effect is even greater when the materials constituting the loop wire and gate electrode 221, and the materials constituting the jumper wire and source and drain electrodes 222 are also common. In addition, when manufacturing such a wireless device, the circuit 31 and antenna 21 can be manufactured in one go, so there is no need to bond an IC (integrated circuit), such as a silicon semiconductor, to the antenna substrate. This makes it possible to provide a wireless device that is thin, highly flexible, and highly reliable with no peeling of the IC.

When the materials of the loop wire and the jumper wire are the same as those of the gate electrode 221 and the source and drain electrodes 222 of the thin film transistor forming the circuit 31, respectively, it is preferable that they are determined from the material and configuration required for the thin film transistor in terms of the electrical characteristics and ease of manufacture of the thin film transistor. For example, it is preferable that the material of the loop wire is selected so as to realize a desired flat band voltage in the flat band characteristics determined by the gate electrode 221 and the semiconductor layer 300 of the thin film transistor. It is also preferable that the material of the jumper wire is selected so as to realize a desired Schottky barrier in the Schottky junction between the source and drain electrodes 222 of the thin film transistor and the semiconductor 300. From these viewpoints, it is preferable that the material of the loop wire and the material of the jumper wire are different from each other.

(Embodiment 3)
7 is a schematic plan view showing the configuration of a wireless device according to embodiment 3 of the present invention. Here, this wireless device 102 has a configuration including a sensing unit 40 connected to the circuit 32 via two wires 400 in addition to the configuration of the wireless device according to embodiment 1.

Examples of the sensing unit 40 include a moisture detection sensor that detects the presence or absence of moisture, a humidity sensor that detects humidity, and a temperature sensor that detects temperature.

The number of wirings 400 is not limited to two, and may be one, three or more, and is not particularly limited as long as the desired sensing is possible. The wirings 400 cross over the loop line via an insulating film (not shown). It is preferable that this insulating layer (not shown) is common to the insulating film 250 present at the intersection of the loop line and the jumper line.

7, the line width of the wiring 400 is shown as constant, but since the loop line may be affected by the electrical capacitance due to the intersection of the loop line and the wiring 400, and the wireless communication characteristics may be deteriorated, the line width of the wiring 400 at the intersection of the loop line and the wiring 400 should not be thick, and it is preferable to make it thinner than the line width of the wiring 400 at the other parts of the intersection. In addition, the line width of the loop line at the intersection with the wiring 400 may be made thinner than other parts to reduce the electrical capacitance of the intersection of the wiring 400 and the loop line. Here, the area where the line width of the wiring 400 is narrowed may be an area that is slightly expanded from the intersection, including not only directly above the intersection but also before and after it. This is in consideration of manufacturing variations, and the manufacturer can freely set the amount of expansion as appropriate. Of course, the area where the line width of the wiring 400 is narrowed may be only directly above the intersection.

The material of the wiring 400 can be the same as that of the antenna 20. From the viewpoint of manufacturing costs, it is preferable that the wiring 400 is made of the same material as the jumper wire and is formed at the same time as the jumper wire.

The wiring 400 may transmit a digital signal that is the result of digital processing of the information sensed by the sensing unit 40, or may transmit the analog information sensed by the sensing unit 40 as is.

The circuit 32 includes a sensing processing unit that processes the sensing results of the sensing unit 40 according to the specifications and characteristics of the sensing unit 40, and a wireless transmission unit that transmits the sensing results to the outside of the wireless device 102 via the antenna 20.

Figure 8 is a block diagram showing a schematic diagram of the vicinity of the circuit 32 connected to the antenna 20 in the wireless device 102 shown in Figure 7. The sensing processing unit connected to the sensing unit 40 processes the signal generated by the sensing unit 40 and transmits the sensing result as a digital signal to the functional circuit. The functional circuit generates an output signal according to the sensing result and transmits the result to the wireless transmission unit, and the wireless transmission unit transmits the result to a power circuit connected to the antenna, thereby changing the impedance of the antenna from the power circuit and communicating the sensing result to the outside.

In the third embodiment, the wireless transmission unit is connected to the power circuit, but the wireless transmission unit may be directly connected to the antenna. As long as the sensing results obtained by the sensing unit 40 are communicated to the outside, the configuration, control method, and connection are not particularly limited. As long as the sensing results can be wirelessly communicated to the outside, the protocol, frequency, communication method, modulation method, and the like are not particularly limited for the method of communicating the sensing results to the outside. Furthermore, while FIG. 8 shows the circuit 32 consisting of the power circuit, functional circuit, sensing processing unit, and wireless transmission unit, it may include circuits and elements having other functions, and as long as the desired characteristics are obtained, the configuration is not particularly limited.

It is preferable that the sensing unit 40 is placed outside the coil-shaped antenna 20. This is because it is possible to provide the device with a sensing function without affecting the characteristics of the wireless device determined by the antenna 20.

The wireless device according to the third embodiment described above can realize a wireless device with sensing functions that is low-cost, highly flexible, and has improved portability by eliminating the need for a power source or batteries.

(Embodiment 4)
Fig. 9 is a diagram illustrating a wireless communication system according to embodiment 4 of the present invention. A wireless communication system 500 illustrated in Fig. 9 includes the wireless device 100 according to embodiment 1 described above, and a wireless transceiver 50 and an antenna 51 capable of wirelessly communicating with the wireless device 100.

The wireless device 100 may be only the wireless device shown in the first embodiment, or may be, for example, a wireless device that enables wireless communication by attaching an antenna that allows contactless electrical connection to the wireless device shown in the first embodiment.

The wireless transceiver 50 is capable of supplying power to the wireless device 100 and performing wireless communication. There are no particular limitations on the configuration or structure of the wireless transceiver 50, but it is preferable that the wireless transceiver 50 has the function of transmitting radio waves at a specific frequency and further receiving signals from the wireless device 100 via backscatter communication.

Examples of the antenna 51 include an antenna for communication using electromagnetic waves or a coil antenna for communication using a magnetic field, but there are no particular limitations on the type or size of the antenna as long as it enables the desired communication. Although omitted in FIG. 9, the wireless transceiver 50 is connected to a network line outside the device, and can communicate the results of communication with the wireless device 100 to the outside as necessary.

According to the fourth embodiment described above, communication can be performed between a wireless device and a wireless transceiver, and information about the wireless device can be communicated to the outside.

The wireless device according to the fourth embodiment can be attached to a product and used to prevent counterfeiting of the product. Specifically, whether the product is genuine or counterfeit is determined by wireless communication between the wireless device 100 and the wireless transceiver 50. The method of wireless communication is not particularly limited as long as it can realize the function of preventing counterfeiting. The product is not particularly limited, but it is preferable to apply it to products that are expected to have a relatively high anti-counterfeiting effect, such as relatively expensive brand-name products, cosmetics, and medicines. The wireless device may be attached to the product itself or to its packaging material, and the location and method of attachment are not particularly limited as long as it can realize the function of preventing counterfeiting.

(Embodiment 5)
Fig. 10 is a diagram illustrating a moisture detection system that is a wireless communication system according to embodiment 5 of the present invention. The moisture detection system 501 illustrated in Fig. 10 includes the wireless device 102 according to embodiment 3 described above, and a wireless transceiver 60 and an antenna 61 capable of wireless communication with the wireless device 102.

The wireless device 102 may be only the wireless device shown in embodiment 3, or may be, for example, a wireless device that enables wireless communication by attaching an antenna that can be electrically connected in a non-contact manner to the wireless device shown in embodiment 3.

Here, the sensing unit of the wireless device 102 detects moisture. For example, moisture can be detected by detecting changes in electrical characteristics, specifically conductivity, capacitance, impedance, etc., caused by moisture adhering to the sensing unit, and transmitting the result to the circuit. Note that moisture detection may detect two states, the presence or absence of moisture, or may detect multiple states according to the amount of moisture.

According to the fifth embodiment described above, a moisture detection system can be provided in which a wireless device communicates with a wireless transceiver and the wireless device can communicate to the outside the result of detecting moisture.

(Embodiment 6)
The wireless communication system according to the sixth embodiment of the present invention is an opening detection system having the same configuration as that of the fifth embodiment, except that the sensing unit of the wireless device 102 shown in the fifth embodiment detects whether or not packaging material, etc. has been opened.

The sensing unit of the wireless device 102 is not particularly limited in configuration or material as long as the electrical state changes when the packaging material or the like is opened, but this can be realized, for example, by adopting a configuration in which the sensing unit changes from an electrically conductive state to a non-conductive state when the packaging material or the like is opened. More specifically, for example, the sensing unit 40 in the wireless device 102 is disposed so as to straddle the opened portion of the packaging material or the like, and when the packaging material or the like is opened, the wiring in the sensing unit 40 is disconnected, making it possible to detect the opening.

According to the sixth embodiment described above, it is possible to provide an opening detection system in which communication is performed between a wireless device and a wireless transceiver, and the wireless device is able to communicate to the outside the result of detecting opening.

(Seventh embodiment)
A wireless communication system according to the seventh embodiment of the present invention is a temperature detection system having the same configuration as that of the fifth embodiment, except that the sensing unit of the wireless device 102 shown in the fifth embodiment detects temperature.

The sensing section of the wireless device 102 is not particularly limited in terms of configuration or material, so long as the electrical state changes with a change in temperature, but it is preferable that the sensing section be of a configuration and/or material that changes electrical conductivity with a change in temperature. Note that the temperature sensing here may detect the temperature itself, or may be a method in which the sensing result changes only when the temperature is above or below a certain temperature.

According to the seventh embodiment described above, it is possible to provide a temperature detection system in which a wireless device communicates with a wireless transceiver and information relating to the temperature detected by the wireless device can be communicated to the outside.

10, 11 Substrate 20, 21 Antenna 30-32 Circuit 40 Sensing section 50, 60 Wireless transceiver 51, 61 Antenna 100-102 Wireless device 201, 211 Spiral (loop) section 202, 212 Jumper section 203A, 203B, 213A, 213B Contact 204A, 204B, 214A, 214B Intersection 220 Thin film transistor 221 Gate electrode 222 Source and drain electrodes 250, 251 Insulating film 300 Semiconductor layer 400 Wiring 500 Wireless communication device 501 Moisture detection system

Claims (15)

A wireless device comprising a substrate, a coil-shaped antenna, and a circuit,
the antenna has an intersection portion at which at least a part of the antenna intersects with an insulating film therebetween;
A wireless device, wherein a line width of the antenna at the intersection is narrower than a line width of at least a part of the antenna other than the intersection. The wireless device according to claim 1, wherein the insulating film has a thickness of 1 μm or less. The wireless device of claim 1, wherein the line width of the antenna in the non-intersecting portion of the antenna is greater than 100 μm and smaller than 2000 μm. The wireless device of claim 1, wherein the line width of the antenna at the intersection is greater than 10 μm and smaller than 500 μm. The wireless device according to claim 1, wherein at least a portion of the circuit section is disposed inside the antenna section formed in a coil shape. The wireless device according to claim 1, wherein the thickness of the antenna at the intersection is different above and below. The wireless device according to claim 1, wherein the material of the antenna at the intersection is different above and below. The wireless device of claim 1, wherein at least one of the insulating films included in the elements in the circuit is shared with the insulating film at the intersection. A wireless device as claimed in claim 1, which is used for anti-counterfeiting purposes. The wireless device according to claim 1, further comprising a sensing unit connected to the circuit. A wireless device according to claim 9, wherein the sensing unit is disposed outside the antenna unit formed in a coil shape. A wireless communication system including a wireless device according to any one of claims 9 to 11 and a wireless communication device capable of supplying power to the wireless device and wirelessly communicating with the wireless device. A moisture detection system including a wireless device according to claim 10 or 11, and a wireless communication device capable of supplying power to the wireless device and wirelessly communicating with the wireless device, wherein the sensing unit detects moisture. An opening detection system including the wireless device according to claim 10 or 11 and a wireless communication device capable of supplying power to the wireless device and wirelessly communicating with the wireless device, the sensing unit detecting whether or not a package has been opened. A temperature detection system including the wireless device according to claim 10 or 11 and a wireless communication device capable of supplying power to the wireless device and wirelessly communicating with the wireless device, wherein the sensing unit detects temperature.

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