KR20230100606A - Method for manufacturing layered structure and method for manufacturing electronic device - Google Patents

Abstract

(Problem) A layered structure provided with a layer containing carbon nanotubes is produced with good productivity.
(Means for solution) The manufacturing method of a layered structure is provided with the 1st process - the 5th process. In the first step, a first coating solution containing a dispersoid containing carbon nanotubes and a liquid as a dispersion medium in which the dispersoid is dispersed is applied to the main surface of the substrate. In the second step, a drying treatment is performed on the first coating liquid applied to the main surface. In the third step, the liquid described above is removed while being denatured, and a first layer containing a dispersoid is formed. In the fourth step, the second coating solution containing the precursor of the polymeric material is applied to the first layer from the side opposite to the main surface. In the fifth step, the precursor is polymerized to form a second layer containing a polymeric material.

Description

Method for manufacturing a layered structure, method for manufacturing an electronic device

The present disclosure relates to methods of manufacturing layered structures and methods of manufacturing electronic devices.

BACKGROUND ART Lightness and flexibility are desired for electronic devices, for example, display devices whose typical examples are liquid crystal displays and organic EL (Electro Luminescence) displays. For example, a plastic film (eg polyimide film) is formed on a carrier substrate (eg glass substrate) serving as a substrate, and a thin-film-transistor (TFT) circuit is formed on the plastic film, The carrier substrate is peeled off from the plastic film. The electronic device obtained in this way is lightweight and rich in flexibility.

Patent Document 1 exemplifies a method of peeling a carrier substrate from a plastic film, a method of peeling by immersion treatment, a method of peeling using a laser, and a method of peeling by forming an adhesive layer between the carrier substrate and the plastic film. .

Patent Document 2 discloses a technique of peeling a polyimide film from a glass substrate without using a laser. Patent Literature 2 exemplifies a structure in which a release layer containing carbon nanotubes is formed between a glass substrate as a carrier substrate and a polyimide film as a plastic film. Patent Document 2 discloses a technique of forming a release layer by applying a dispersion liquid containing carbon nanotubes as a dispersoid to a glass substrate and evaporating the dispersion medium of the dispersion liquid.

Japanese Unexamined Patent Publication No. 2015-165491 Japanese Unexamined Patent Publication No. 2019-144347

In the peeling method using a laser, for example, after baking the surface of the plastic film on the carrier substrate side with a laser, the plastic film is mechanically pulled and peeled from the carrier substrate. This method is called the EPLaR (Electronics on Plastic by Laser Release) method. In the EPLaR method, a high-output laser gives strong damage to a plastic film, for example, a polyimide film. Stress is generated in the plastic film by this damage. Due to this stress, the plastic film after peeling is deformed so as to be rolled up. This deformation can damage circuits formed on the plastic film. An expensive laser annealing apparatus is employed for the EPLaR method.

Patent Literature 2 discloses formation of a release layer, but does not disclose details of the improvement in efficiency at the time of forming the release layer.

The present disclosure provides a technique for producing a layered structure including a layer containing carbon nanotubes with good productivity.

A method for producing a layered structure according to the present disclosure includes a first step of applying a first coating solution having a dispersoid containing carbon nanotubes and a liquid as a dispersion medium in which the dispersoid is dispersed to a main surface of a substrate; a second step of drying the first coating liquid applied to the main surface; a third step of forming a first layer containing the dispersoid by removing the liquid while denaturing; a polymer A fourth step of applying a second coating solution containing a material precursor to the first layer from the side opposite to the main surface, and a fifth step of polymerizing the precursor to form a second layer containing the polymer material. have a process

Forming the structure on the side opposite to the main surface with respect to the second layer is easy since the substrate serves as a support layer during formation of the structure. After the structure is formed, it is easy to separate the substrate from the second layer.

1 is a flowchart illustrating a manufacturing process of an electronic device.
2 is a side view showing the substrate.
3 is a side view showing a state in which a release layer is formed on a substrate.
4 : is a side view which shows the state in which the polyimide layer was formed on the peeling layer.
5 : is a top view which shows the state in which the polyimide layer was formed on the peeling layer.
6 is a cross-sectional view showing a state in which a barrier layer is formed on the polyimide layer.
7 is a plan view showing a state in which a barrier layer is formed on the polyimide layer.
8 is a cross-sectional view showing a state in which a circuit layer is formed on the barrier layer.
9 is a cross-sectional view illustrating a step of peeling the laminate from the substrate.
10 is a flowchart illustrating formation of a release layer.
Fig. 11 is a side view schematically showing an aspect of irradiating ultraviolet light while moving a substrate.
12 is a side view schematically showing an aspect of irradiating ultraviolet light without moving the substrate.
13 is a flow chart showing another example of formation of a release layer.
14 is a side view schematically showing generation of reactive plasma.

<1. Overall description of the manufacturing process of electronic devices>

1 is a flowchart illustrating a manufacturing process of an electronic device. The electronic device concerned is, for example, a display device. 2 is a side view of the substrate 10 viewed from a direction perpendicular to its thickness direction.

Step S10 is a step of preparing the substrate 10 . The substrate 10 has a smooth main surface 10a. For the substrate 10, plate-shaped glass is employed, for example. The substrate 10 has a surface 10b opposite to the main surface 10a in the thickness direction. The thickness direction can be said to be a direction perpendicular to the main surface 10a. In FIGS. 1 to 8 , a direction P is a direction from the main surface 10a to the surface 10b in the thickness direction of the substrate 10 .

When viewed from a plane viewed along the direction P, the shape or size of the substrate 10 is not particularly limited. For example, in a planar view, the substrate 10 has a rectangular shape. When viewed from a plane, it corresponds to viewing from a direction perpendicular to the main surface 10a.

The substrate 10 functions as a carrier substrate for holding and transporting the polyimide layer 30 and the circuit layer 50 (or additionally the barrier layer 40) described later in the manufacturing process of the electronic device. The substrate 10 does not remain in the electronic device as a final product.

By using the substrate 10 as a carrier substrate, the flexible polyimide layer 30 is stably maintained, and the circuit layer 50 is easily formed on the polyimide layer 30 . Using the substrate 10 as a carrier substrate facilitates the manufacture of electronic devices using existing, general manufacturing equipment (e.g., coating equipment, heat treatment equipment) for forming circuit layers on substrates.

Step S11 is a step of applying the first coating liquid 102 on the substrate 10 prepared in step S10. Here, "on the substrate 10" has the same meaning as "on the main surface 10a". The first coating liquid 102 is applied to the main surface 10a by a known method, for example, a slit coating method.

In the slit coating method, a slit coater is used, for example. The slit coater scans, for example, a slit nozzle that discharges the first coating liquid 102 as a coating liquid at a constant speed with respect to the substrate 10 maintained in a stationary state. By controlling the application range of the coating liquid, the first coating liquid 102 enters the main surface 10a of the substrate 10 in plan view. 3 is a side view showing a state in which the first coating liquid 102 is applied on the substrate 10 .

Between step S10 and step S11, a process of cleaning the main surface 10a may be performed. Examples of such a treatment include chemical cleaning in which the main surface 10a is cleaned with a chemical solution, brush cleaning in which contaminants are mechanically removed from the main surface 10a with a brush, and contamination by irradiating the main surface 10a with ultraviolet rays. A treatment to decompose and remove substances is exemplified.

The first coating liquid 102 is a dispersion and has a dispersoid and a liquid to be dispersed. In the manufacturing method related to the present disclosure, the dispersoid includes carbon nanotubes. The liquid to be dispersed contains a dispersion medium, and a dispersoid is dispersed in the dispersion medium. As the dispersion medium, either or both of an aqueous liquid and an organic liquid are employed. The liquid to be dispersed may further contain a dispersing agent. Examples of dispersants include surfactants. The dispersant is not limited to a liquid, and may be a solid.

Step S12 is a process of performing a process of drying the first coating liquid 102 (referred to simply as "drying process" in the drawings and below). As an example of this drying process, reduced-pressure drying and heating are mentioned. By this drying treatment, at least a part of the dispersion medium in the first coating liquid 102 is reduced.

Step S13 is a process of forming the peeling layer 20 with the 1st coating liquid 102 after the drying process was performed. For example, step S13 is a step of forming the release layer 20 containing a dispersoid by removing the liquid to be dispersed while denaturing it. Here, "denaturation" includes, as one aspect, decomposition of the liquid to be dispersed, and various aspects are exemplified below.

By removing the liquid to be dispersed, the peeling layer 20 is obtained as a ground material in which carbon nanotubes are entangled with each other. Ground material is a porous film formed of a fibrous material. The carbon nanotube itself is a fibrous material. By removing the liquid to be dispersed from the first coating liquid 102, a ground object in which fibrous carbon nanotubes are entangled with each other is formed. The film thickness of the peeling layer 20 is 100 nm or less, for example.

Step S14 is a process of applying the second coating liquid 103 to the peeling layer 20 . More specifically, the second coating liquid 103 is applied to the release layer 20 from the side opposite to the main surface 10a. The second coating liquid 103 is applied to the release layer 20 by a known method, for example, a slit coating method.

In this embodiment, the 2nd coating liquid 103 enters the main surface 10a, covering the peeling layer 20 in planar view. The second coating liquid 103 is also applied to the main surface 10a around the release layer 20 . In plan view, the second coating liquid 103 located outside the release layer 20 is in contact with the main surface 10a.

4 : is a side view which shows the state in which the 2nd coating liquid 103 was apply|coated on the peeling layer 20. As shown in FIG. In Fig. 4, the outer edge 20f of the release layer 20 in plan view is shown.

Step S15 is a process of forming the polyimide layer 30 with the second coating liquid 103. For example, step S15 includes polymerization. The film thickness of the polyimide layer 30 is about 10 μm.

The second coating liquid 103 contains a precursor of a polymer material, a polyimide precursor in the example of this embodiment. Step S15 is a step of polymerizing the precursor to form a layer containing a polymer material, the polyimide layer 30 in the example of the present embodiment. For example, step S15 heats the 2nd coating liquid 103 together with the board|substrate 10 at 350 degreeC or more, and imidates it. In step S15, a heat treatment furnace is used, for example. In the heat treatment furnace, the substrate 10 is heated by blowing hot air.

5 : is a plan view which shows the state in which the polyimide layer 30 was formed on the peeling layer 20. As shown in FIG. The peripheral portions of the four sides of the polyimide layer 30 protruding from the outer edge 20f of the peeling layer 20 are outside the outer edge 20f and contact the main surface 10a.

The release layer 20 is a porous film having a fibrous structure, and the second coating liquid 103 easily enters the minute irregularities of the fibrous structure. Adhesion between the polyimide layer 30 obtained by polymerization and the release layer 20 is high. The main surface 10a is smooth, and the adhesion between this and the release layer 20 is low. The peelability between the substrate 10 and the release layer 20 is higher than that between the polyimide layer 30 and the release layer 20 .

If the adhesiveness between the peeling layer 20 and the substrate 10 becomes low, there arises a possibility that the peeling layer 20 is peeled from the substrate 10 in the middle of the manufacturing process of the display device. The polyimide layer 30 at a portion outside the outer edge 20f of the release layer 20 in contact with the main surface 10a is separated from the substrate 10 during the manufacturing process of the display device. It has the function of suppressing

Step S40 is a process of forming the barrier layer 40 on the polyimide layer 30. 6 is a cross-sectional view showing a state in which the barrier layer 40 is formed on the polyimide layer 30. As shown in FIG. 7 is a plan view showing a state in which the barrier layer 40 is formed on the polyimide layer 30 .

The barrier layer 40 is a layer for preventing penetration of moisture into the circuit layer 50 described later, and is composed of, for example, a silicon nitride (SiNx) film. The barrier layer 40 is formed by various well-known methods, such as the CVD method, for example.

The barrier layer 40 is formed in a predetermined region R on the polyimide layer 30 . The predetermined region R is surrounded by the outer edge 20f in plan view.

Step S16 is a process of forming the circuit layer 50 on the barrier layer 40. 7 is a plan view showing a state in which the circuit layer 50 is formed on the barrier layer 40 . 8 is a cross-sectional view showing a state in which the circuit layer 50 is formed on the barrier layer 40 . The barrier layer 40 is formed in a predetermined region R in plan view, and the circuit layer 50 is the same.

For example, the circuit layer 50 has an electronic circuit including thin film transistors. The circuit layer 50 is formed by a known array process in which steps such as film formation, photolithography, and etching are repeated. After formation of the circuit layer 50, an organic EL layer or a sealing layer may be further formed.

Step S17 is executed after the circuit layer 50 is formed. Step S17 is a process of cutting the polyimide layer 30 and the peeling layer 20. Step S18 is executed after step S17 is executed. Step S18 is a process of peeling the substrate 10 from the peeling layer 20. Steps S17 and S18 together can be said to be steps of peeling the layered product 60 including the peeling layer 20, the polyimide layer 30, the barrier layer 40, and the circuit layer 50 from the substrate 10. may be

9 is a cross-sectional view illustrating steps S17 and S18 or a step of peeling the layered product 60 from the substrate 10. As shown in FIG. In step S17, the polyimide layer 30 and the peeling layer 20 are cut between the outer edge 20f and the predetermined region R. In step S18, the laminate 60 is mechanically removed from the substrate 10. In FIG. 9 , chain lines indicate positions where the polyimide layer 30 and the release layer 20 are cut, and the separated laminate 60, the polyimide layer 30 remaining on the substrate 10, and the release The positional relationship of the layer 20 is shown.

While the adhesiveness of the peeling layer 20 and the polyimide layer 30 is high, the adhesiveness of the peeling layer 20 and the board|substrate 10 is low. When the laminate 60 including the polyimide layer 30 is mechanically pulled, the interface between the release layer 20 and the substrate 10 is easily separated. Accordingly, the polyimide layer 30 is easily peeled from the substrate 10 while reducing damage to the polyimide layer 30 .

The layered product 60 after peeling has a configuration in which an electronic circuit is formed on a thin polyimide substrate. Such a layered body 60 is provided as a main component of a flexible device with abundant flexibility, for example, a display device.

Since the adhesiveness of the peeling layer 20 and the polyimide layer 30 is high, the peeling layer 20 remains stuck to the polyimide layer 30 in the laminated body 60. The peeling layer 20 is, for example, a ground object having a film thickness of 100 nm or less, and it is difficult to disturb the flexibility of the layered product 60 . The peeling layer 20 may have a function as a barrier layer.

Step S17 can be omitted in some cases. For example, when the area of the periphery of the polyimide layer 30 in contact with the substrate 10 is small, the layered product 60 may be simply mechanically pulled and removed from the substrate 10 . This treatment is the same even when the second coating liquid 103 is applied to the release layer 20 without exceeding the outer edge 20f and the polyimide layer 30 does not contact the substrate 10.

In this embodiment, a release layer 20 is placed between the substrate 10 and the polyimide layer 30 . The release layer 20 has high adhesion to the polyimide layer 30, but low adhesion to the substrate 10. By mechanically pulling the polyimide layer 30, the polyimide layer 30 is easily peeled from the substrate 10 together with the release layer 20. The release layer 20 functions as a debonding layer.

According to the present embodiment, the polyimide layer 30 is easily peeled from the substrate 10 even without baking and cutting the polyimide layer 30 using a laser or the like. Since an expensive laser annealing apparatus is unnecessary, the polyimide layer 30 is peeled from the board|substrate 10 cheaply.

According to this embodiment, since a laser is not used for peeling of the polyimide layer 30, the damage given to the polyimide layer 30 when peeling the polyimide layer 30 from the board|substrate 10 is small. Therefore, stress is generated in the polyimide layer 30, and the polyimide layer 30 is not easily deformed by winding, and mechanical damage to the circuit layer 50 on the polyimide layer 30 is also suppressed. Suppression of such deformation and damage contributes to the improvement of the manufacturing yield of the device using the laminated body 60.

The carbon nanotubes included in the peeling layer 20 have conductivity. Such conductivity contributes to suppressing generation of static electricity when the polyimide layer 30 is separated from the substrate 10 . Suppression of generation of static electricity contributes to suppression of electrical damage to the circuit layer 50 .

<2. Description of the manufacturing method of layered structure>

Steps S11 to S15 can be considered to be a manufacturing method of the following layered structure in which the release layer 20 is illustrated as the first layer and the polyimide layer 30 is illustrated as the second layer.

Step S11 can be said to be a first step of applying, on the main surface 10a of the substrate 10, the first coating liquid 102 containing a dispersoid containing carbon nanotubes and a liquid to be dispersed in which the dispersoid is dispersed. can

Step S12 can be said to be a second step of drying the first coating liquid 102 applied to the main surface 10a.

Step S13 can be said to be a third step of forming a first layer (release layer 20 in the above-described example) containing a dispersoid by removing the liquid to be dispersed while denaturing it.

Step S14 can be said to be a fourth step of applying the second coating liquid 103 containing a polymer material precursor (polyimide precursor in the above-described example) to the first layer from the side opposite to the main surface 10a. can

Step S15 can be said to be a fifth step of polymerizing the precursor to form a second layer (polyimide layer 30 in the above example) containing a polymer material (polyimide in the above example).

Forming the structure (circuit layer 50 in the above-described example) on the side opposite to the main surface 10a with respect to the second layer is easy because the substrate 10 serves as a support layer during formation of the structure. After the structure is formed, it is easy to separate the substrate 10 from the second layer.

Below, various methods mainly in steps S12 and S13 are explained.

<2-1. Denaturation of liquid to be dispersed by light irradiation>

10 is a flow chart illustrating the contents of step S13 (formation of release layer 20). Light irradiation is performed in step S13a, and heat treatment is performed in step S13b. After step S13b is executed, the process returns to the flow chart shown in Fig. 1 (specifically, the execution of step S14 is started).

Specifically, in step S13a, light having a wavelength of 300 nm or less (hereinafter referred to as "ultraviolet light") is irradiated to the first coating liquid 102 . Irradiation of such light generates oxygen radicals in the vicinity of the first coating liquid 102 . The first coating liquid 102 contains, for example, an organic substance in the dispersion medium contained in the liquid to be dispersed, or contains an organic substance in the dispersant that can be contained in the liquid to be dispersed, and the organic substance is mainly carbon, hydrogen, and oxygen. It is a compound containing

By introducing carbon atoms (C), hydrogen atoms (H), oxygen atoms (O), and oxygen radicals (O*), the oxygen radicals (O*) decompose organic matter to produce carbon monoxide, carbon dioxide, and water as follows: do. This decomposition is one aspect of the denaturation described above. Carbon monoxide and carbon dioxide are removed from the first coating liquid 102 as a gas, and water as a liquid or gas, and a dispersion medium containing carbon nanotubes is deposited on the main surface 10a.

C + O* → CO,

C + 2O* → CO ₂ ,

2H + O* → H ₂ O

In this embodiment, as a light source of ultraviolet light, a deep ultraviolet light emitting diode, a low-pressure mercury lamp, and an excimer lamp are illustrated, for example. Low-pressure mercury lamps mainly produce light with a wavelength of 254 nm. Excimer lamps mainly produce light with a wavelength of 172 nm.

After irradiation of light in step S13a, step S13b is executed. In step S13b, heating at 350°C is performed, for example. For example, after irradiating the 1st coating liquid 102 with the ultraviolet-ray of 1000 mJ per square centimeter by the low-pressure mercury lamp in step S13a, heating at 350 degreeC is performed for 30 minutes in step S13b.

In the modification of the liquid to be dispersed using oxygen radicals (O*), the high-temperature treatment is easily omitted compared to the removal of the liquid to be dispersed by simple heating. For example, when oxygen radicals (O*) are not used, heating of about 500°C is required to remove the liquid to be dispersed. In contrast, by using oxygen radicals (O*), the heating temperature may be low, and the efficiency of forming the release layer 20 is improved.

Heating may accompany step S13a. For example, vacuum drying is employed in step S12, ultraviolet light is irradiated with heating at a first temperature in step S13a, and heat treatment is performed at a second temperature higher than the first temperature in step S13b. do.

For example, drying treatment is performed by heating in step S12, and step S13a is executed without heating or while maintaining heating. After that, step S13b is performed at a temperature higher than the heating in step S12. For example, in steps S12 and S13a, heating at 100 to 150°C is employed.

The fact that the heat treatment in step S13b does not exceed 700°C contributes to not deteriorating the properties of the carbon nanotubes in the release layer 20 .

Regarding the execution of step S13a, two aspects are proposed. FIG. 11 is a side view schematically showing an aspect of irradiating ultraviolet light while moving the substrate 10. As shown in FIG. Fig. 12 is a side view schematically showing an aspect of irradiating ultraviolet light without moving the substrate 10;

The excimer lamp 8 has a plurality of lamp tubes 81. Each of the lamp tubes 81 extends along a direction M drawn perpendicular to the paper plane. A plurality of lamp tubes 81 are arranged along the direction Q. The direction Q is non-parallel to the direction M, and a case orthogonal to the direction M is exemplified here.

The substrate 10 coated with the first coating liquid 102 is disposed so that its direction P is non-parallel to any of the directions M and Q. Here, a case where the direction P is orthogonal to the directions M and Q is exemplified. The substrate 10 is placed with the first coating liquid 102 facing the excimer lamp 8 .

In the aspect shown in Fig. 11, the substrate 10 moves along the direction Q. The substrate 10 is conveyed in the direction Q while the surface 10b is supported by a plurality of rollers 9 extending along the direction M, for example. Rotation of the roller 9 in the clockwise direction in the drawing contributes to the movement of the substrate 10 in the direction Q.

The aspect shown in FIG. 11 requires a transport mechanism, but the number of lamp tubes 81 may be small. In the aspect shown in Fig. 12, a transport mechanism is unnecessary, but a large number of lamp tubes 81 are required.

<2-2. Denaturation of liquid to be dispersed by plasma>

Fig. 13 is a flowchart illustrating other contents of step S13. Generation of reactive plasma is performed in step S13c, and heat treatment is performed in step S13d, respectively. After step S13d is executed, the process returns to the flowchart shown in Fig. 1 (specifically, the execution of step S14 is started).

The temperature of the heat treatment performed in step S13d is, for example, 200°C or higher. The fact that the heat treatment in step S13d does not exceed 700°C contributes to not deteriorating the properties of the carbon nanotubes in the release layer 20 .

In Step S13c, a reactive plasma is generated in the vicinity of the first coating liquid 102 (hereinafter also referred to as "reactive plasma is generated"). As the reactive gas used for generating the reactive plasma, an aspect in which an oxidizing gas is used and an aspect in which a reducing gas are used are exemplified.

Oxygen gas is exemplified as the oxidizing gas, and a mixed gas of, for example, oxygen gas and argon gas is used to generate the reactive plasma. Hydrogen gas is exemplified as the reducing gas, and a mixed gas of, for example, hydrogen gas and argon gas is used to generate the reactive plasma. Since the generation of reactive plasma using these mixed gases is well known, details thereof are omitted.

When oxygen gas is used to generate the reactive plasma, the generated oxygen plasma supplies oxygen radicals (O*) to the first coating liquid 102 . By the same chemical reaction as the irradiation with ultraviolet light described above, a dispersion medium containing carbon nanotubes is deposited on the main surface 10a.

When hydrogen gas is used to generate the reactive plasma, the generated hydrogen plasma supplies hydrogen radicals (H*) to the first coating liquid 102 . By introducing hydrogen radicals (H*), the hydrogen radicals (H*) decompose organic matter to produce water as follows. This decomposition is one aspect of the denaturation described above. Water is removed from the first coating liquid 102 as a liquid or gas, and a dispersion medium containing carbon nanotubes is present on the main surface 10a.

O + 2H* → H ₂ O

In organic matter, the binding energy of C-H is 413 KJ/mol, the binding energy of O-H is 463 KJ/mol, and the binding energy of C=O is 799 KJ/mol. The binding energy of C=O is greater than that of C-H. Hydrogen radicals (H*) can also cleave bonds in organic substances in the same way as oxygen radicals (O*).

Hydrogen has a lower interatomic dissociation energy than oxygen, and is more likely to be plasma discharged. Reactive plasma using hydrogen gas tends to generate more plasma than oxygen gas.

14 is a side view schematically illustrating generation of reactive plasma. The chamber 7 accommodates a pair of electrodes 83. A mixed gas 82 is supplied between the pair of electrodes 83 . The mixed gas 82 is supplied from the outside of the chamber 7, and an aspect supplied between a pair of electrodes 83 is exemplified here.

The mixed gas 82 is a mixed gas of argon gas and oxygen gas, or a mixed gas of argon gas and hydrogen gas, if it says based on the example mentioned above. For example, atmospheric pressure plasma is employed as the reactive plasma.

The substrate 10 coated with the first coating liquid 102 moves along the direction Q in the chamber 7 while directing the first coating liquid 102 toward the electrode 83 . Similarly to FIGS. 11 and 12, also in FIG. 14, the case where the direction Q is orthogonal to the direction P is exemplified.

The substrate 10 is conveyed in the direction Q while the surface 10b is supported by a plurality of rollers 9, for example. Each of the rollers 9 extends along a direction M orthogonal to any of the directions P and Q. Rotation of the roller 9 in the clockwise direction in the drawing contributes to the movement of the substrate 10 in the direction Q.

Reactive plasma is generated in the region J lying between the electrodes 83 . From the region J, oxygen radicals (O*) or hydrogen radicals (H*) diffuse toward the substrate 10 and are supplied to the first coating liquid 102 . Reactive plasma is generated on the side opposite to the main surface 10a with respect to the liquid to be dispersed in the first coating liquid 102 .

Similar to irradiation with ultraviolet light, the denaturation of the liquid to be dispersed using oxygen radicals (O*) generated by the reactive plasma using the oxidizing gas is also higher than the removal of the liquid to be dispersed by simple heating. easy to omit Modification of the liquid to be dispersed by reactive plasma using a reducing gas is also the same. For example, when the liquid to be dispersed is denatured and removed by reactive plasma, step S13d may be omitted.

Patent Literature 2 discloses drying a coating film formed by applying a dispersion liquid to evaporate the dispersion medium, but does not specify a technique for removing the dispersant. When the dispersing agent is contained in the liquid to be dispersed, the dispersing agent is removed while being denatured by, for example, heating the first coating liquid 102 at a temperature of 500°C for about 30 minutes. Such heat treatment may be a factor in reducing the efficiency of forming the release layer 20 . In the modification exemplified in the embodiment, the temperature required for heat treatment is low, and the efficiency of forming the release layer 20 is improved.

<3. Description of manufacturing method of electronic device>

Steps S16, S17, and S18, together with steps S11 to S15 for manufacturing the layered structure, can be considered as a method for manufacturing an electronic device equipped with an electronic circuit included in the circuit layer 50.

The circuit layer 50 can be said to be an example of a third layer formed on a second layer exemplified by the polyimide layer 30 and having an electronic circuit. Step S16 can be said to be a sixth step of forming, for example, a third layer illustrated by the circuit layer 50 in the predetermined region R on the second layer illustrated by the polyimide layer 30. .

Step S17 cuts the first layer exemplified by the release layer 20 and the second layer exemplified by the polyimide layer 30 between the outer edge 20f and the predetermined region R in plan view. It can be called the 7th process. In this case, step S18 can be said to be the eighth step of peeling the substrate 10 from the first layer.

Alternatively, when step S17 is omitted, it can be said that step S18 is the seventh step described above.

＜Transformation＞

As mentioned above, although embodiment of this indication was described, this indication can implement various changes other than what was mentioned above, unless it deviated from the meaning. For example, formation of the barrier layer 40 may be omitted and the circuit layer 50 may be directly formed on the polyimide layer 30 .

The above-described technology can be used for production of display devices such as organic EL displays and liquid crystal displays, for example, for production of flexible devices in which circuits are formed on polyimide substrates.

10: Substrate
10a: give
20: exfoliation layer (first layer)
20f: outer edge
30: polyimide layer (second layer)
50: circuit layer (third layer)
102: first coating liquid
103: second coating liquid
C: carbon atom
H: hydrogen atom
H* : hydrogen radical
O: oxygen atom
O* : Oxygen radical
P: direction (perpendicular to the principal plane)
R: predetermined area
S11: step (first process)
S12: step (second process)
S13: step (third process)
S14: step (fourth process)
S15: step (5th process)
S16: step (6th process)
S17: step (seventh process)
S18: step (8th process; 7th process)

Claims (10)

A first step of applying a first coating solution having a dispersoid containing carbon nanotubes and a liquid as a dispersion medium in which the dispersoid is dispersed to the main surface of the substrate;
a second step of subjecting the first coating liquid applied to the main surface to a drying treatment;
a third step of forming a first layer including the dispersoid by removing the liquid while denaturing;
a fourth step of applying a second coating solution containing a precursor of a polymeric material to the first layer from a side opposite to the main surface;
A method for producing a layered structure comprising a fifth step of polymerizing the precursor to form a second layer containing the polymer material. According to claim 1,
The method for producing a layered structure in which oxygen radicals are supplied to the liquid in the third step. According to claim 2,
In the third step, the oxygen radical is generated using light having a wavelength of 300 nm or less. According to claim 2,
In the third step, the oxygen radical is generated using oxygen plasma. According to claim 1,
In the third step, a reactive plasma is generated on a side opposite to the main surface with respect to the liquid. According to claim 5,
A method for producing a layered structure, wherein the reactive plasma is generated using an oxidizing gas as a reactive gas. According to claim 5,
A method for producing a layered structure, wherein the reactive plasma is generated using a reducing gas as a reactive gas. According to any one of claims 1 to 7,
In the fourth step, the second coating liquid is also applied to the main surface around the first layer. A method of manufacturing an electronic device having an electronic circuit, comprising:
The first step to the fifth step of the method for manufacturing the layer structure according to any one of claims 1 to 7;
a sixth step of forming a third layer having the electronic circuit on the second layer;
A method for manufacturing an electronic device comprising: a seventh step of peeling the substrate from the first layer after the sixth step. A method of manufacturing an electronic device having an electronic circuit, comprising:
The first step to the fifth step included in the method for manufacturing the layer structure according to claim 8;
a sixth step of forming a third layer having the electronic circuit on the second layer in a predetermined area surrounded by an outer edge of the first layer as viewed in a direction perpendicular to the main surface;
a seventh step of cutting the first layer and the second layer between the outer edge of the first layer and the predetermined region as viewed from the direction after the sixth step;
An electronic device manufacturing method comprising: an eighth step of peeling the substrate from the first layer after the seventh step.

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