JP5407423B2 - Electronic apparatus and electronic device - Google Patents

Description

  The present invention relates to a flexible electronic apparatus and electronic device.

Conventionally, electronic devices such as a flexible display, an image sensor, and an RFID (Radio Frequency Identification) tag have been developed by forming a thin film transistor circuit on a flexible substrate.
Here, Patent Document 1 describes a method of peeling using an SOI substrate for manufacturing an integrated circuit using a thin film transistor circuit and RFID (Radio Frequency Identification). Patent Document 2 describes a semiconductor device that can restrict transmission / reception of a signal or a power supply voltage to / from a reader / writer by peeling after being attached to an object.

  Patent Document 3 describes a thin film integrated circuit device including a thin film active element such as a thin film transistor (TFT) circuit. Patent Document 4 describes a semiconductor device mounting structure that improves heat dissipation from an IC chip, prevents malfunction of the semiconductor device, and improves operation reliability of the semiconductor device. Patent Document 5 describes a flexible electronic device that achieves flexibility by bonding after processing a substrate to be thin.

JP 2005-203751 A JP 2005-228304 A JP 2005-235191 A Japanese Patent No. 3444618 Japanese Patent No. 4063082

Here, a plastic film or substrate is used as the flexible substrate, but due to the nature of the base material, high temperature (about 250 ° C.) cannot be applied during manufacturing, and the performance of the thin film transistor circuit is fully exhibited. It was difficult. This is because the thin film transistor circuit has a property that changes depending on the temperature applied when the polysilicon layer or the gate insulating film as an active layer is formed. The optimum value of the crystallization energy at the time of laser crystallization changes depending on the hydrogen concentration. In the gate insulating film, the interface state density (MidDit) that determines the insulating properties and TFT characteristics changes depending on the temperature applied during the film formation.
Therefore, when the applied temperature is low, the optimum value of the crystallization energy of the polysilicon layer changes and the interface state density of the gate insulating film also changes. It becomes difficult to make it appear.

By the way, in patent documents 1-patent documents 5, since a resin substrate is used and high temperature cannot be applied at the time of manufacture, it is difficult to fully demonstrate the performance of a thin film transistor circuit.
Furthermore, if an antenna element and a chip of a non-contact type data carrier circuit are simply formed on a flexible substrate at the same time, there is a problem that the area of the antenna element becomes larger than the area of the chip.
Further, if a non-contact type data carrier circuit is formed as it is on a flexible metal substrate, the circuit cannot secure a certain operating characteristic.

  In the present invention, a thin film transistor circuit capable of exhibiting performance sufficiently by applying a high temperature at the time of manufacturing while utilizing the cost merit of the metal substrate is mounted, and the antenna element of the non-contact type data carrier circuit on the flexible substrate It is an object of the present invention to provide an electronic device and an electronic device that can realize a reduction in size even when a chip and a chip are formed at the same time, and that guarantee the operating characteristics of a non-contact data carrier circuit.

  The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.

According to the first aspect of the present invention, a flexible substrate (11) made of a metal substrate such as a SUS substrate, and a ferroelectric layer is formed on the plane of the substrate (11). A dielectric layer (12) having a relative dielectric constant equal to or higher than a predetermined relative dielectric constant, and a thin film transistor circuit (14a) formed on a plane of the dielectric layer (12) and applied with high temperature after being formed And an electronic element forming layer (14) on which an electronic element (13) that exhibits a function as a non-contact type data carrier circuit is formed.

According to a second aspect of the invention, in the electronic device according to claim 1 (1), a plane of the substrate (11), said dielectric layer (12) is not formed side of the plane is An electronic device (1), wherein an antenna element (15) of the non-contact type data carrier circuit is formed.

A third aspect of the present invention, in the electronic device according to claim 1 (1), wherein the electronic element formation layer (14), said non-contact antenna elements of the circuit for the data carrier (15) is formed of It is an electronic device (1) characterized by having.

A fourth aspect of the present invention is an electronic device using the electronic apparatus (1) according to any one of the first to third aspects.

According to the present invention, the following effects can be obtained.
(1) Since the present invention has a dielectric layer having a relative dielectric constant equal to or higher than a predetermined relative dielectric constant, an electronic element (for example, an antenna element formed for communicating with an external device) due to a wavelength shortening effect. Can be reduced in size.
(2) Since a metal substrate is used in the present invention, a high temperature can be applied at the time of manufacture, and the performance of a thin film transistor circuit configured as an electronic element can be sufficiently exhibited.
(3) In the present invention, since the dielectric layer is composed of a ferroelectric layer, the size of the electronic element (for example, an antenna element formed for communication with an external device) is reduced by the wavelength shortening effect. Can be
(4) The electronic element formation layer functions as a non-contact type data carrier circuit (for example, an RFID circuit). Therefore, in the present invention, by forming a non-contact type data carrier chip with a thin film transistor circuit formed on a flexible substrate, chip cracking, cracking, etc. due to stress such as bending, compared to a silicon-based non-contact type data carrier chip. Occurrence can be reduced.
(5) In the present invention, since the antenna element is formed by processing the substrate, it is equivalent to forming the antenna element on the ferroelectric layer, and the antenna element and the data carrier circuit are reduced by the wavelength shortening effect. Miniaturization and cost reduction can be achieved.
(6) In the present invention, since the antenna element is formed on the electronic element forming layer and the antenna element is formed on the ferroelectric layer, the antenna element and the data carrier circuit can be downsized by the wavelength shortening effect. Cost can be reduced.
The thin film transistor circuit functions as an RFID thin film transistor circuit by being combined with an antenna element for communicating with an external device. In an RFID card equipped with a general RFID thin film transistor circuit, the resonance frequency and its characteristics change when it is close to a metal (external device). Therefore, in the present invention, a substrate composed of a metal substrate is combined with an antenna element in advance and adjusted so as to avoid a phenomenon in which the resonance frequency and its characteristics change due to proximity to the metal in the manufacturing stage. By configuring in this way, in the present invention, it is possible to suppress the resonance frequency and its characteristics from changing even in the vicinity of the external device (reader / writer device). The substrate is used as a metal substrate for suppressing characteristic changes.
(7) In the present invention, an electronic element (for example, an antenna element formed to communicate with an external device) has a dielectric layer having a relative dielectric constant equal to or higher than a predetermined relative dielectric constant, and has a wavelength shortening effect. An electronic device having an electronic device with a reduced size can be configured.

It is sectional drawing which shows the structure of an electronic device typically. It is a figure where it uses for description about the difference of each value of (lambda) / 4 when changing the dielectric constant of a dielectric material layer. In the case of a dipole antenna having an electromagnetic wave frequency of 900 MHz, it is a diagram for explaining the length of an antenna element when a dielectric layer having a high relative dielectric constant is used. In the case of a loop antenna having a resonance frequency of 13.56 MHz, it is a diagram for explaining a change in wavelength when a dielectric layer having a high relative dielectric constant is used and a frequency corresponding to the changed wavelength. It is a figure where it uses for description about the change of the capacity | capacitance of a coil when changing the capacity | capacitance of a capacitor | condenser in case the resonant frequency is 303 MHz. It is a figure where it uses for description about the manufacturing method of an electronic device. It is a figure which shows typically the plane and cross section of the manufactured electronic device. It is a figure where it uses for description about the manufacturing method of an electronic device. It is a figure which shows typically the plane and cross section of the manufactured electronic device.

  Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. FIG. 1 shows a cross-sectional view of an electronic device 1 as a non-contact data carrier device using a thin film transistor circuit formed on a flexible metal substrate. According to the electronic device 1 according to the present embodiment, it is possible to reduce the size of the electronic element (for example, an antenna element formed for communication with an external device), and to reduce the cost. .

  In order to exert the effect, the electronic device 1 includes a flexible substrate 11, a dielectric layer 12, and an electronic element forming layer 14 as shown in FIG. 1. The dielectric layer 12 is formed on the plane of the substrate 11 and has a relative dielectric constant equal to or higher than a predetermined relative dielectric constant. The electronic element formation layer 14 is formed on the plane of the dielectric layer 12, and the electronic element 13 that exhibits a predetermined function is formed. As will be described in detail later, as an example of the electronic element formation layer 14, a thin film transistor circuit 14a is formed on the upper surface of the dielectric layer 12.

  Since the electronic device 1 configured as described above has a dielectric layer having a relative dielectric constant equal to or higher than a predetermined relative dielectric constant, the electronic device 1 is formed to communicate with an electronic element (for example, an external device) due to a wavelength shortening effect. Antenna element) can be reduced in size.

Moreover, in the electronic device 1, it is preferable that the board | substrate 11 is comprised by metal substrates, such as a SUS board | substrate.
In the present embodiment, since a metal substrate such as a SUS substrate is used as the substrate 11, a high temperature (250 ° C. or more) can be applied at the time of manufacture, and the performance of the thin film transistor circuit as the electronic element formation layer 14 is sufficient It can be demonstrated.

  In this embodiment, the thin film transistor circuit functions as an RFID thin film transistor circuit by being combined with an antenna element for communicating with an external device. In an RFID card equipped with a general RFID thin film transistor circuit, the resonance frequency and its characteristics change when it is close to a metal (external device). Therefore, in the electronic apparatus 1 according to the present embodiment, the resonance frequency and its characteristics when the RFID is installed on the metal object by combining the substrate 11 formed of the metal substrate with the antenna element in advance and approaching the metal in the manufacturing stage. Make adjustments to avoid the phenomenon that changes. With this configuration, the electronic device 1 according to the present embodiment can be suppressed so that the resonance frequency and its characteristics do not change even when the electronic device 1 is close to the external device (reader / writer device). Therefore, in this embodiment, the substrate 11 is used as a metal substrate for suppressing characteristic changes.

  Since the electronic device 1 configured as described above uses a metal substrate, a high temperature can be applied during manufacture, and the performance of the thin film transistor circuit configured as an electronic element can be sufficiently exhibited.

In the electronic device 1, the dielectric layer 12 is preferably composed of a ferroelectric layer. Note that a ferroelectric material can freely change the direction of spontaneous polarization in a material (a state in which electrical positive or negative occurs in the material) by applying a voltage, and the polarization direction can be maintained without applying a voltage. It is a dielectric (a substance that stores electric charge by polarization and does not pass a direct current). In the present specification, the relative dielectric constant (εr) is preferably 100 or more.
Here, there is a problem that the radio wave incident on the electronic device 1 is canceled by the radio wave reflected by the metal substrate 11, and radio wave supply (power supply) to the RFID becomes impossible, and the RFID does not operate. Theoretically, a predetermined clearance (for example, λ / 4 (quarter of wavelength)) is formed between the substrate 11 and the electronic element formation layer 14 by the dielectric layer 12, so that a metal substrate is formed. When the radio wave having a reflection phase of 180 ° by 11 is further shifted by 180 °, cancellation by the incident radio wave and the reflected radio wave is eliminated, and a change in radio wave supply to the RFID can be reduced.

Differences in the values of λ / 4 when the relative dielectric constant (εr) of the dielectric layer 12 is changed in an antenna for a certain frequency band will be described.
In the dipole antenna of the electromagnetic wave frequency 2.45GHz band, if the dielectric constant of the dielectric layer 12 (.epsilon.r) is 1, the wavelength (lambda ₀₎ is approximately 0.122m, λ _0/4 is approximately zero. 03 m (3 mm).
Next, for example, when the dielectric layer 12 having a relative dielectric constant (εr) of 20000 is formed between the substrate 11 and the electronic element formation layer 14, from the equation (1),
λd = λ ₀ / √εr (1)
The wavelength (λd) is about 0.87 mm, and λd / 4 is about 0.22 mm (see FIG. 2). For example, when the dielectric layer 12 having a relative dielectric constant (εr) of 500 is formed between the substrate 11 and the electronic element forming layer 14, the wavelength (λd) is about 5.47 mm from the equation (1). , Λd / 4 is about 1.37 mm (see FIG. 2).

Further, the dipole antenna of the electromagnetic wave frequency 900MHz band, if the dielectric constant of the dielectric layer 12 (.epsilon.r) is 1, the wavelength (lambda ₀₎ is about 0.33 m, lambda _0/4 is approximately zero. It becomes 08 mm.
Next, for example, when the dielectric layer 12 having a relative dielectric constant (εr) of 20000 is formed between the substrate 11 and the electronic element formation layer 14, the wavelength (λd) is about 2.36 mm from the equation (1). Yes, λd / 4 is about 0.59 mm (see FIG. 2). For example, when the dielectric layer 12 having a relative dielectric constant (εr) of 500 is formed between the substrate 11 and the electronic element forming layer 14, the wavelength (λd) is about 14.9 mm from the equation (1). Λd / 4 is approximately 3.72 mm (see FIG. 2).

Further, in the loop antenna of the resonant frequency is 13.56 MHz, if the dielectric constant (.epsilon.r) is 1, the wavelength (lambda ₀₎ is about 22.11mm, λ _0/4 is about 5.53mm .
Next, for example, when the dielectric layer 12 having a relative dielectric constant (εr) of 20000 is formed between the substrate 11 and the electronic element forming layer 14, the wavelength (λd) is about 156 mm from the equation (1). λd / 4 is about 39.1 mm (see FIG. 2). For example, when the dielectric layer 12 having a relative dielectric constant (εr) of 500 is formed between the substrate 11 and the electronic element forming layer 14, the wavelength (λd) is about 989 mm from the equation (1), and λd / 4 is about 247 mm (see FIG. 2).

  In this way, λ / 4 is shortened as the dielectric layer 12 has a higher relative dielectric constant (εr). Therefore, since the electronic device 1 uses the dielectric layer 12 having a high relative dielectric constant (εr), the overall size can be reduced and the cost can be reduced.

Next, the wavelength shortening effect by providing the dielectric layer 12 having a high relative dielectric constant (εr) will be described.
For example, in the case of a dipole antenna having an electromagnetic frequency band of 900 MHz, the wavelength (λ ₀ ) is about 0.33 m as described above, and the length of the antenna element (for example, λ / 2) is about 0.17 m. (170 mm). Next, when the dielectric layer 12 having a relative dielectric constant of 20000 is used, the length (λ / 2) of the antenna element is about 1.18 mm from the equation (1) due to the wavelength shortening effect. Further, when the dielectric layer 12 having a relative dielectric constant of 500 is formed on the surface of the substrate 11, the length (λ / 2) of the antenna element is about 7.45 mm from the equation (1) due to the wavelength shortening effect. (See FIG. 3).
In this manner, the electronic device 1 can shorten the antenna element by forming the dielectric layer 12 on the substrate 11, can reduce the overall size, and can reduce the cost. be able to.

In the case of a loop antenna having a resonance frequency of 13.56 MHz, the wavelength (λ ₀ ) is about 22.1 m as described above. When the dielectric layer 12 having a relative dielectric constant (εr) of 20000 is formed on the surface of the substrate 11, the wavelength (λd) is about 0.16 m from the equation (1). Note that a wavelength of about 0.16 m substantially corresponds to a wavelength of a frequency of about 1928 MHz (1.928 GHz) (see FIG. 4).
When the dielectric layer 12 having a relative dielectric constant (εr) of 500 is formed on the surface of the substrate 11, the wavelength (λd) is about 0.99 m according to the equation (1). Note that a wavelength of about 0.99 m substantially corresponds to a wavelength of a frequency of about 303 MHz (see FIG. 4).

Further, when the frequency is 303 MHz and the capacitance of the capacitor (c) is 30 pF, from the equation (2),
f = 1 / 2π√LC (2)
When the capacity of the coil (L) is about 0.0092 μH, the frequency is 303 MHz, and the capacity of the capacitor (c) is 5 pF, the capacity of the coil (L) is If the frequency is 303 MHz and the capacitance of the capacitor (c) is 1 pF, the capacitance of the coil (L) is about 0.2759 μH from equation (2).
When the resonance frequency is 13.56 MHz and the capacitance of the capacitor (c) is 30 pF, the capacitance of the coil (L) is about 5.6 μH from the equation (2) (see FIG. 5). ).

  Therefore, by using the dielectric layer 12 having a high relative dielectric constant (εr), the wavelength shortening effect can be exhibited, and the inductance of the coil (L) is lowered (the length of the coil (L) is shortened). Therefore, the antenna element itself can be formed short.

Moreover, in the electronic device 1, the electronic element formation layer 14 is comprised by the thin-film transistor circuit 14a, and it is preferable to exhibit the function as a non-contact-type data carrier circuit.
In the electronic device 1 configured as described above, for example, by forming a non-contact type data carrier chip with a thin film transistor circuit 14a formed on a flexible substrate corresponding to the substrate 11, a silicon-based non-contact type data carrier chip is formed. In comparison, it is possible to reduce the occurrence of chip cracks, cracks and the like with respect to stress such as bending.

In the electronic device 1, the antenna element 15 of the non-contact type data carrier circuit is formed on the plane of the substrate 11 on the side where the dielectric layer 12 is not formed. Is preferred.
In the electronic device 1 configured as described above, since the antenna element 15 is formed by processing the substrate 11, it is not necessary to provide the antenna element as a separate member, and the antenna element 15 is provided on the dielectric layer 12. Since this is equivalent to the formation and has a wavelength shortening effect, the antenna element 15 and the data carrier circuit can be reduced in size and cost.
Further, the non-contact data carrier circuit can be operated on the metal substrate 11 by using the flexible substrate itself which is the metal substrate 11 as the antenna element 15 and using the ferroelectric layer as the buffer layer. Is possible.

In the electronic device 1, the electronic element forming layer 14 is preferably formed with an antenna element 15 of a non-contact type data carrier circuit.
The electronic device 1 configured as described above is equivalent to forming an antenna element on a ferroelectric layer, and produces a wavelength shortening effect. Therefore, the antenna element and the data carrier circuit are reduced in size and cost. be able to.

Next, a method for manufacturing the electronic device 1 having a resonance frequency of 13.56 MHz will be described. Hereinafter, FIGS. 6A to 6E are cross-sectional views in the process of manufacturing the electronic device 1.
In the electronic device 1, as shown in FIGS. 6A and 6B, a dielectric layer 12 having a relative dielectric constant equal to or higher than a predetermined relative dielectric constant is formed on a plane of a flexible metal substrate 11. Here, although the flat surface of the substrate 11 is not rough and flat, it can be flattened by forming the dielectric layer 12 on the surface thereof.
As shown in FIG. 6C, the electronic device 1 creates a thin film transistor circuit 14 a as an electronic element forming layer 14 on the plane of the dielectric layer 12. In this embodiment, since the substrate 11 is made of metal, it is possible to apply a high temperature in the production of the thin film transistor circuit 14a, and it is possible to produce the thin film transistor circuit 14a that exhibits sufficient performance.
In addition, as shown in FIGS. 6D and 6E, the electronic device 1 forms an interlayer insulating film 14b and a via hole 14c (through hole) on the thin film transistor circuit 14a as the electronic element formation layer 14. Then, after the metal layer is formed, the antenna element 14d is formed by performing patterning, etching, and the like.
Moreover, in FIG. 7, the top view of the electronic device 1 and sectional drawing when cut | disconnected by AA are shown.

Next, a method for manufacturing the electronic device 1 that functions as an RFID for the UHF band will be described. In addition, below, Fig.8 (a)-(e) shows sectional drawing in the process in which the electronic device 1 is produced.
As shown in FIGS. 8A and 8B, the electronic device 1 forms a dielectric layer 12 having a relative dielectric constant equal to or higher than a predetermined relative dielectric constant on a plane of a flexible metal substrate 11. Here, although the flat surface of the substrate 11 is not rough and flat, it can be flattened by forming the dielectric layer 12 on the surface thereof.
As shown in FIG. 8C, the electronic device 1 creates a thin film transistor circuit 14 a as an electronic element formation layer 14 on the plane of the dielectric layer 12. In this embodiment, since the substrate 11 is made of metal, it is possible to apply a high temperature in the production of the thin film transistor circuit 14a, and it is possible to produce the thin film transistor circuit 14a that exhibits sufficient performance.
Further, in the electronic device 1, as shown in FIGS. 8D and 8E, an interlayer insulating film 14b is formed on the thin film transistor circuit 14a as the electronic element forming layer 14, and a via hole 14c (through hole) is formed. Then, after the metal layer is formed, the antenna element 14d is formed by performing patterning, etching, and the like.
FIG. 9 shows a plan view of the electronic device 1 and a cross-sectional view taken along the line AA.

Here, the points of the electronic apparatus 1 according to the present embodiment are summarized.
1. Since the electronic device 1 includes the dielectric layer 12 having a relative dielectric constant equal to or higher than a predetermined relative dielectric constant, the size of the electronic element 13 can be reduced due to the wavelength shortening effect.
2. Since the electronic device 1 uses a metal substrate (for example, a SUS substrate) as the substrate 11, a high temperature can be applied at the time of manufacture, and the performance of the thin film transistor circuit 14a configured as the electronic element 13 is sufficiently exhibited. be able to.
3. In the electronic device 1, since the dielectric layer 12 is composed of a ferroelectric layer (for example, the relative dielectric constant ε is 100 or more), the size of the electronic element 13 can be reduced by the wavelength shortening effect.
4). The electronic element formation layer 14 functions as a non-contact type data carrier circuit (for example, an RFID circuit). Therefore, the electronic device 1 includes a thin film transistor circuit 14a formed on the flexible substrate 11 to form a non-contact type data carrier chip, so that chip cracking due to stress such as bending is less than that of a silicon-based non-contact type data carrier chip. It is possible to reduce the occurrence of cracks and the like.
5. Since the electronic device 1 forms the antenna element by processing the substrate 11, it is equivalent to forming the antenna element 15 on the dielectric layer 12, and the antenna element 15 and the data carrier circuit are obtained by the wavelength shortening effect. Can be reduced in size and cost.
6). Since the electronic device 1 forms the antenna element 15 on the electronic element formation layer 14, as a result, it is equivalent to forming the antenna element 15 on the dielectric layer 12. Thus, it is possible to reduce the size and cost of the data carrier circuit.

  As an advanced form, the electronic device may be provided with the electronic apparatus 1 according to the present embodiment. Such an electronic device has a dielectric layer having a relative dielectric constant equal to or higher than a predetermined relative dielectric constant, and an electronic element (for example, an antenna element formed to communicate with an external device) due to a wavelength shortening effect. It is possible to provide the electronic device 1 that is reduced in size.

DESCRIPTION OF SYMBOLS 1 Electronic device 11 Substrate 12 Dielectric layer 13 Electronic element 14 Electronic element formation layer 14a Thin film transistor circuit 15 Antenna element

Claims (4)

A flexible substrate made of a metal substrate such as a SUS substrate;
A dielectric layer formed on a plane of the substrate and composed of a ferroelectric layer and having a relative dielectric constant equal to or higher than a predetermined relative dielectric constant;
The formed on a plane of the dielectric layer is formed of a thin film transistor circuit high temperature is applied after being formed, an electronic element formation layer electronic device that serves the function as a circuit for a data carrier for contactless is formed An electronic device comprising: The electronic device according to claim 1,
An electronic device, wherein an antenna element of the non-contact type data carrier circuit is formed on a plane of the substrate on which the dielectric layer is not formed. The electronic device according to claim 1,
An electronic device, wherein an antenna element of the non-contact type data carrier circuit is formed in the electronic element formation layer.   An electronic device using the electronic device according to any one of claims 1 to 3.

Images