JP7511183B2 - Functional device and method for manufacturing the same - Google Patents

Description

This disclosure relates to functional devices and methods for manufacturing functional devices.

In recent years, there has been much research being done on the use of printing methods to form various electronic devices. Printing methods apply the required amount of ink only to the required locations, and therefore use materials more efficiently than methods such as vacuum deposition and sputtering.

Among printing methods, the inkjet method is attracting attention because it does not come into contact with the object to be printed and can form the desired pattern on demand.

Examples of electronic devices formed using printing methods include wiring made with conductive ink, transistors made with semiconducting ink, and display devices made with light-emitting materials.

Patent document 1 discloses an organic EL device, which is an example of an electronic device. The bank of the organic EL device of Patent document 1 has a relatively high liquid repellency in order to keep the ink, which is the material of the hole transport layer and the organic light emitting layer, within the area defined by the bank.

Patent No. 4990415

When manufacturing an organic EL device with a bank that has high liquid repellency, if the transparent cathode located above the light emitting layer and the functional layers such as the transparent sealing film are formed by a coating process such as the inkjet method, this leads to a decrease in the uniformity of the film thickness of the functional layers.

Similarly, when manufacturing an organic transistor device with a bank that has high liquid repellency, if the source electrode, drain electrode, and functional layers such as a protective film are formed by a coating process such as an inkjet method, this leads to a decrease in the uniformity of the film thickness of the functional layers.

If a highly uniform film is not formed, the quality of functional devices such as organic EL devices and organic transistor devices will be reduced.

The purpose of this disclosure is to provide a functional device and a method for manufacturing a functional device that allows for efficient use of materials and ensures high quality.

A functional device according to one aspect of the present disclosure comprises a bank having a liquid-repellent portion and a low-liquid-repellent portion on its surface, the low-liquid-repellent portion having lower liquid-repellency than the liquid-repellent portion, a first functional layer located in an area defined by the bank and in contact with the liquid-repellent portion, and a second functional layer in contact with the low-liquid-repellent portion and covering the first functional layer , wherein the surface portion includes a side portion of the bank, and the low-liquid-repellent portion is provided on a part of the side portion .

A method for manufacturing a functional device according to one aspect of the present disclosure includes the steps of forming a bank on a substrate, forming a first functional layer located in an area defined by the bank and in contact with a liquid-repellent portion of a surface portion of the bank, forming a low-liquid-repellent portion in a portion of a side portion of the bank included in the surface portion , the low-liquid-repellent portion having relatively lower liquid-repellency than the liquid-repellent portion, and forming a second functional layer in contact with the low-liquid-repellent portion and covering the first functional layer.

The present disclosure provides a functional device and a method for manufacturing a functional device that allows for efficient use of materials and ensures high quality.

A cross-sectional view showing the structure of an organic EL device disclosed in Patent Document 1. FIG. 1 is a cross-sectional view showing a structure of a functional device according to an embodiment of the present disclosure. FIG. 1 is a cross-sectional view showing an intermediate product according to an embodiment in a state where an electrode layer and a bank are formed on a substrate. FIG. 1 is a diagram showing an intermediate product being irradiated with _CF4 plasma according to an embodiment; FIG. 1 is a cross-sectional view of an intermediate product according to an embodiment with ink pooled in the light-emitting area; FIG. 1 is a cross-sectional view of an intermediate product according to an embodiment in which a light-emitting layer has been formed. FIG. 1 is a diagram showing an intermediate product according to an embodiment being irradiated with _O2 plasma through a shielding mask; FIG. 1 is a cross-sectional view of an intermediate product according to an embodiment in which an electrode layer has been formed; FIG. 1 is a cross-sectional view showing a structure of a functional device according to a first modified example of the present disclosure. FIG. 11 is a cross-sectional view showing a structure of a functional device having another structure according to the first modified example of the present disclosure. FIG. 11 is a cross-sectional view showing a structure of a functional device according to a second modified example of the present disclosure. FIG. 11 is a cross-sectional view showing a structure of a functional device according to a third modified example of the present disclosure. FIG. 1 is a cross-sectional view showing an intermediate product according to Example 1 in a state where an electrode layer and a bank are formed on a substrate. FIG. 1 is a cross-sectional view showing an intermediate product according to Example 1 in which a red light-emitting layer has been formed. FIG. 1 is a diagram showing an intermediate product according to Example 1 being irradiated with _O2 plasma through a shielding mask. FIG. 1 is a cross-sectional view showing a structure of a functional device according to a first embodiment; FIG. 11 is a cross-sectional view showing an intermediate product according to Example 2 in a state where an electrode layer and a bank are formed on a substrate. FIG. 13 is a diagram showing an intermediate product according to Example 2 being irradiated with _CF4 plasma. FIG. 11 is a cross-sectional view showing an intermediate product according to Example 2 in which a red light-emitting layer has been formed. FIG. 1 is a cross-sectional view showing an intermediate product being contained in a vacuum dryer. FIG. 11 is a cross-sectional view showing the structure of a functional device according to a second embodiment;

In this specification, the term "functional device" is a general term for a device that uses physical phenomena to output a desired function. Examples of functional devices include organic electroluminescence devices, quantum dot light-emitting devices, color conversion filter devices, organic transistor devices, and sensor devices.

(Technical Background)
Functional materials such as light emitting materials and conductive materials used in the manufacture of functional devices, particularly light emitting devices, are very expensive, and it is therefore desirable to minimize material waste.

The printing method is a method that allows the application of the required amount of ink only in the required positions, and therefore has a higher material utilization efficiency than methods such as vacuum deposition and sputtering. Furthermore, the printing method allows the deposition of a film in the atmosphere, not in a vacuum. For this reason, the printing method does not require the energy required to operate vacuum equipment, and is therefore also desirable from the perspective of reducing operating energy. In this specification, the term "ink" refers to the material of a specified layer that is in a liquid state.

Printing methods include screen printing, letterpress printing, intaglio printing, and the inkjet method. In particular, the inkjet method has attracted attention, and there has been active development of methods for forming display devices such as color filters, organic electroluminescence displays, and quantum dot displays using the inkjet method.

One of the next-generation displays is one that uses inorganic quantum dot material as the light-emitting layer. Development of such displays is currently underway.

Quantum dots are special semiconductors that are very small, specifically, with a diameter of 2 to 10 nm (in other words, about 10 to 50 atoms). Thus, materials that are tiny in size have different properties than those that are relatively large in size.

In quantum dots, the size of the band gap can be controlled simply by changing the quantum particle size. Because the emission wavelength of a quantum dot depends on the size of the band gap, the emission wavelength of a quantum dot can be adjusted very precisely. That is, the emission wavelength of a quantum dot can be changed simply by changing the quantum particle size. More specifically, the smaller the quantum particle size, the more the emission wavelength of the quantum dot shifts toward the blue side, and the larger the quantum particle size, the more the emission wavelength shifts toward the red side.

The half-width of the emission wavelength is very small, at less than a few tens of nanometers. Because the half-width of the emission wavelengths of red, blue, and green are small, the emission wavelengths exhibit wide color gamut characteristics. As a result, the performance of the device as a display device is dramatically improved.

Quantum dots are composed of a core, a layer called a shell that is formed around the core, and ligands that are formed around the shell. Typical core materials are inorganic materials such as cadmium-selenium, indium-phosphorus, copper-indium-sulfur, and silver-indium-sulfur, as well as inorganic materials with a perovskite structure. A typical shell material is zinc sulfide, etc.

Quantum dots achieve stability as inks by forming ligands around the shell. Light-emitting devices made from such quantum dot materials include photoluminescence devices, in which the electrons in the quantum dot material are excited by light energy to emit light, and electroluminescence devices, in which the electrons are excited by electrical energy to emit light.

Photoluminescent devices are used as color filters in micro-LED displays, which are an example of quantum dot displays.

Electroluminescent devices are an example of quantum dot displays, and are used in quantum dot light-emitting displays, which are formed by depositing a thin film of quantum dot material between an anode and a cathode.

Quantum dot displays, which use photoluminescence or electroluminescence devices, have much higher brightness than organic EL displays and have excellent visibility outdoors. For this reason, they are expected to be used in applications such as displays for mobile phones and in-vehicle displays, as well as head-mounted displays. These displays are expected to require a pixel resolution of 200 ppi (pixels per inch) or more.

The light-emitting materials that form light-emitting devices such as photoluminescent devices and electroluminescent devices lose their light-emitting performance due to the influence of moisture in the air. For this reason, when manufacturing these devices, it is necessary to form a sealing film after forming the light-emitting layer. The sealing film is often made of a silicon nitride film and a laminated film such as an acrylic resin film or an epoxy resin film. The silicon nitride film is formed by a vacuum process called CVD (Chemical Vapor Deposition). The laminated film is formed by the inkjet method.

For the following reasons (1) to (3), there has been active development of methods for forming functional devices by forming all layers and films using coating processes such as inkjet methods, without using vacuum processes.

(1) Material Loss When manufacturing functional devices using vacuum processes such as deposition, sputtering, and CVD, a large amount of material is lost. Since the materials of the films that constitute functional devices are very expensive, it is desirable to minimize the amount of material lost.

(2) Cost. Vacuum equipment has high operating costs, so the use of vacuum processes increases the costs required to manufacture functional devices.

(3) Manufacturing at low temperatures Methods for forming functional devices on flexible substrates such as plastic films are being actively developed. Since flexible substrates have low heat resistance, when using flexible substrates as substrates, it is necessary to manufacture functional devices at low temperatures.

Efforts are being made to form all layers of functional devices using coating processes, with the goals of increasing the efficiency of material usage, reducing manufacturing costs by producing functional devices under atmospheric pressure, and producing functional devices at temperatures that the plastic film can withstand.

<Problems with the coating process>
FIG. 1 is a cross-sectional view showing the structure of an organic EL device 1 (an example of a functional device) disclosed in Japanese Patent Application Laid-Open No. 2003-233996.

The organic EL device 1 includes a TFT panel 10, an anode 12, a hole injection layer 13, a hole transport layer 14, an organic light-emitting layer 15, a bank 16, an electron injection layer 18, a transparent cathode 20, and a transparent sealing film 22.

In the manufacture of the organic EL device 1, the functional layers such as the organic light emitting layer 15 are formed by an inkjet method. Specifically, the organic EL device 1 is manufactured by the following procedure.
(1) An anode (electrode) 12 and a hole injection layer 13 are formed on a TFT panel 10 .
(2) A bank 16 that defines a pixel region is formed on the hole injection layer 13 .
(3) A hole transport layer 14 and an organic light emitting layer 15 are formed by an ink jet method within the region defined by the bank 16 .
(4) On the organic light-emitting layer 15, an electron injection layer 18 and a transparent cathode 20 are formed by a vacuum process.
(5) A transparent sealing film 22 is formed so as to cover the electron injection layer 18 and the transparent cathode 20 .

The bank 16 must have a certain level of liquid repellency to hold the ink, which is the material of the hole transport layer 14 and the organic light emitting layer 15, in a specified area. For this reason, the bank 16 has a relatively high level of liquid repellency.

When manufacturing an organic EL device 1 having the structure shown in FIG. 1, if the transparent cathode 20 and the transparent sealing film 22 are formed by an inkjet method, the film formation performance of the transparent cathode 20 and the transparent sealing film 22 is significantly degraded.

Specifically, because the bank 16 has a relatively high liquid repellency, the coating film formed from the ink is repelled by the bank 16, resulting in a decrease in the uniformity of the film thickness of the transparent cathode 20 and the transparent sealing film 22, as well as a decrease in the coverage of the transparent sealing film 22.

In particular, if the uniformity of the film thickness of the transparent cathode 20 decreases, the resistance value of the organic EL device 1 varies, causing deterioration of the electrical characteristics. As a result, the light-emitting characteristics of the organic EL device 1 may deteriorate. Furthermore, if the coverage of the transparent sealing film 22 decreases, moisture in the air may penetrate into the organic EL device 1 through the thin parts of the transparent sealing film 22, adversely affecting the organic light-emitting layer 15. As a result, the light-emitting characteristics of the organic EL device 1 deteriorate over time.

Another functional device will now be described. If an organic transistor device has a bank with relatively high liquid repellency, when functional layers such as source electrodes, drain electrodes, and protective films are formed by the inkjet method, the ink for the functional layers applied onto the bank is repelled. This reduces the uniformity of the functional layers. As a result, the quality of the organic transistor device is reduced.

As such, when forming a functional device using the inkjet method, the relatively high liquid repellency of the bank may lead to a deterioration in the quality of the functional device.

The functional device disclosed herein can be manufactured using a coating process for many of the functional layers while ensuring quality.

Embodiments of the present disclosure will be described below with reference to the drawings. Note that components common to each drawing are given the same reference numerals, and their description will be omitted as appropriate.

(Embodiment)
2 is a cross-sectional view showing a structure of the functional device 100 according to an embodiment of the present disclosure. In this specification, a cross-sectional view refers to a vertical cross-sectional view of the functional device 100. In this embodiment, the functional device 100 will be described as an organic EL device that emits electroluminescence.

The functional device 100 includes a substrate 110, an electrode layer 120, a bank 130, a first functional layer 140, and a second functional layer 150. In this embodiment, the first functional layer 140 is composed of a light-emitting layer 141, which will be described in detail later. The functional device 100 has a top emission structure in which light emitted by the light-emitting layer 141 is emitted from the upper side of the functional device 100 to the outside.

<Substrate 110>
Various layers are laminated on one surface of the substrate 110. The material of the substrate 110 may be either a transparent material or an opaque material as long as it has insulating properties. The substrate 110 may be a flexible resin sheet such as glass or polyimide.

<Electrode layer 120>
In this embodiment, the electrode layer 120 is composed of a reflective electrode. The electrode layer 120 is formed on the substrate 110. The material of the electrode layer 120 is a metal material with high optical reflectivity, such as a silver-palladium-copper alloy or aluminum. Therefore, the functional device 100 can efficiently emit light emitted from the light-emitting layer 141 to the outside of the functional device 100.

<Bank 130>
The bank 130 is formed so as to cover a portion of the electrode 102. The bank 130 defines a region in which the first functional layer 140 is to be formed.

Generally, the bank 130 is often formed to have relatively high liquid repellency. In addition, the ink applied by a coating process such as the inkjet method often has a low viscosity. Low ink viscosity means that the concentration of solids contained in the ink is low. In other words, in order to ensure that the layer formed after the ink solvent has dried has a certain thickness or more, a corresponding amount of ink needs to be applied.

For example, when the ink 41 (see FIG. 5) of the light-emitting layer 141 is applied in the application process, the ink 41 needs to be stored in the area (hereinafter referred to as the light-emitting area) defined by the bank 130 in order to use the applied ink to form the light-emitting layer 141. If the liquid repellency of the bank 130 is relatively low, the applied ink 41 will overflow from the light-emitting area. If the liquid repellency of the bank 130 is relatively high, the necessary amount of ink 41 can be stored in the light-emitting area. For this reason, from the viewpoint of forming the light-emitting layer 141 to have a sufficient thickness, it is desirable for the bank 130 to have high liquid repellency, that is, low wettability. Here, low wettability means high liquid repellency, and high wettability means low liquid repellency.

However, if the liquid repellency of the bank 130 is relatively high and the second functional layer 150 covering the bank 130 is formed by a coating process such as an inkjet method or screen printing, the ink of the applied second functional layer 150 is repelled by the bank 130. As a result, the uniformity of the second functional layer 150 is reduced. For this reason, from the viewpoint of forming the second functional layer 150, which is the layer above the light-emitting layer 141, with high uniformity, it is desirable for the bank 130 to have low liquid repellency, that is, high wettability.

Therefore, the bank 130 of the functional device 100 according to an embodiment of the present disclosure has areas with high liquid repellency and areas with low liquid repellency. The bank 130 will be described in detail below.

The bank 130 has a surface portion 131 and an interior portion 136. The surface portion 131 covers the interior portion 136 and a portion of the electrode layer 120.

The surface portion 131 has a liquid repellent portion 132 and a low liquid repellent portion 134. The liquid repellent portion 132 is the portion of the surface portion 131 that contacts the first functional layer 140. The liquid repellent portion 132 is the portion of the surface portion 131 other than the liquid repellent portion 132, and is the portion that contacts the second functional layer 150.

The material of the liquid-repellent portion 132 is a photosensitive resin material. The liquid-repellent portion 132 contains a fluorine compound, which is a liquid-repellent component. The material of the low liquid-repellent portion 134 is a photosensitive resin material, similar to the liquid-repellent portion 132. The low liquid-repellent portion 134 may or may not contain a fluorine compound. The photosensitive resin material is specifically a resin material such as an acrylic resin, an epoxy resin, or a polyimide.

The concentration of fluorine atoms in the liquid repellent section 132 is higher than the concentration of fluorine atoms in the low liquid repellent section 134. Specifically, the concentration of fluorine atoms in the liquid repellent section 132 is 5 atom% or more and 10 atom% or less, and the concentration of fluorine atoms in the low liquid repellent section 134 is 0 atom% or more and less than 5 atom%. The fluorine atom concentration can be measured by an X-ray photoelectron spectroscopy (also called XPS or ESCA).

In this way, the low liquid-repellent portion 134 has a lower concentration of liquid-repellent components than the liquid-repellent portion 132, and therefore the low liquid-repellent portion 134 is less liquid-repellent than the liquid-repellent portion 132.

The contact angle of the liquid repellent portion 132 of the first functional layer 140 with respect to the ink is 20 degrees or more and 70 degrees or less, preferably 30 degrees or more and 60 degrees or less. The contact angle of the low liquid repellent portion 134 of the second functional layer 150 with respect to the ink is 0 degrees or more and 30 degrees or less, preferably 0 degrees or more and 20 degrees or less. Here, the contact angle is a value indicating wettability with respect to a liquid, and the larger the contact angle, the smaller the wettability, and the smaller the contact angle, the greater the wettability. Note that the contact angle of the liquid repellent portion 132 and the contact angle of the low liquid repellent portion 134 described above are not contact angles with respect to the same ink, but are values with respect to inks containing different substances. For this reason, it is not recognized that the functional device 100 according to the embodiment has the low liquid repellent portion 134 that has a higher liquid repellency than the liquid repellent portion 132.

The roughness of surface 135, which is the surface in contact with first functional layer 140 in low liquid repellency section 134, is greater than the roughness of surface 133 in liquid repellency section 132. The smaller the roughness, the smaller the coefficient of friction of the surface, and the greater the roughness, the greater the coefficient of friction of the surface.

The material of the interior 136 is a photosensitive resin material, specifically, an acrylic resin, an epoxy resin, or a resin material such as polyimide.

<First functional layer 140>
The first functional layer 140 is located on the electrode layer 120 in a region defined by the bank 130 , and is in contact with the liquid repellent portion 132 .

In this embodiment, the first functional layer 140 is composed of a light-emitting layer 141.

The light-emitting layer 141 includes a red light-emitting layer 141R that emits red light, a green light-emitting layer 141G that emits green light, and a blue light-emitting layer 141B that emits blue light.

The thickness of the light-emitting layer 141 is, for example, several tens of nm. The thickness of the light-emitting layer 141 varies depending on the type of material and the optical design of the device to be manufactured, but is approximately 20 nm or more and 100 nm or less.

The material of the light-emitting layer 141 is a fluorene-based polymeric organic compound. An example of this fluorene-based polymeric organic compound is poly(9,9-dioctylfluorene-alt-benzothiadiazole), commonly known as F8BT.

<Second functional layer 150>
The second functional layer 150 is in contact with the low liquid repellency portion 134 and covers the first functional layer 140 .

In this embodiment, the second functional layer 150 is composed of an electrode layer 151 and a sealing layer 156.

The electrode layer 151 is composed of a transparent electrode. The electrode layer 151 is formed so as to cover a part of the bank 130 and the light-emitting layer 141. The material of the electrode layer 151 is indium-tin oxide (ITO). The electrode layer 151 has high optical transparency, so that the light emitted by the light-emitting layer 141 can be efficiently emitted to the outside of the functional device 100.

The sealing layer 156 is formed so as to cover at least a portion of the bank 130 and the electrode layer 151. It goes without saying that the sealing layer 156 covers the light-emitting layer 141 located below the electrode layer 151. As shown in FIG. 2, in this embodiment, the sealing layer 156 is formed as a so-called solid layer so as to span multiple regions defined by the bank 130.

The material of the sealing layer 156 is a resin material such as a photosensitive epoxy resin or acrylic resin.

The light-emitting layer 141 of the functional device 100 is easily deteriorated by the influence of moisture. The sealing layer 156 protects the light-emitting layer 141 from moisture in the atmosphere.

The sealing layer 156 may only cover a portion of the bank 130 as long as it can protect the light-emitting layer 141 from moisture in the air.

The materials for each layer and bank 130 described above are examples and are not limited to these materials.

<Method of Manufacturing Functional Device 100>
A method for manufacturing the functional device 100 according to this embodiment will be described with reference to Fig. 2 to Fig. 8. In the following description, all objects formed during the manufacturing process of the functional device 100 will be referred to as intermediate products. The method for manufacturing the functional device 100 includes the following steps S1 to S5.

First, the electrode layer 120 is formed on the substrate 110 (step S1). The electrode layer 120 is formed using a material such as aluminum or a silver-palladium-copper alloy by a vacuum deposition method such as sputtering.

Next, a bank 130 is formed so as to cover a portion of the electrode layer 120 (step S2). Step S2 includes step S21 of forming a bank 130 with relatively low liquid repellency, and step S22 of forming a liquid repellent portion 132 on the surface portion 131 of the bank 130. Here, a bank 130 with relatively low liquid repellency refers to a bank 130 that does not have a liquid repellent portion 132 on the surface portion 131, and whose interior 136 also has relatively low liquid repellency.

In step S21, a bank 130 with low liquid repellency is formed by photolithography using a photosensitive resin material. As described above, the photosensitive resin material is a resin material such as an acrylic resin, an epoxy resin, or a polyimide. Step S21 includes the following steps S211 to S214.

First, a photosensitive resin material that hardens when exposed to ultraviolet light is applied to the substrate 110 by spin coating, which is an example of a coating process (step S211). Note that the rotation speed in the spin coating, which is a coating condition, is adjusted according to the required height of the bank 130.

Next, the coating layer is pre-baked using a hot plate or the like to dry the coated material and remove the solvent (step S212). Then, exposure to ultraviolet light is performed through a photomask on which a desired pattern is formed (step S213). Here, among photosensitive resin materials, there are negative materials in which the exposed parts irradiated with ultraviolet light are cured, and positive materials in which the unexposed parts are cured. Depending on the type of material, an appropriate developer is used to remove the uncured parts. Then, the remaining pattern is post-baked in a curing oven or the like (step S214). These steps S211 to S214 form a bank 130 with relatively low liquid repellency. As a result, the intermediate product is in the state shown in FIG. 3, which is a cross-sectional view showing an intermediate product in which an electrode layer 120 and a bank 130 with relatively low liquid repellency are formed on a substrate 110. The bank 130 of the intermediate product shown in FIG. 3 has relatively low liquid repellency.

Next, for the intermediate product of Fig. 2, a liquid repellent portion 132 is formed on the surface portion 131 of the bank 130 (step S22). In this embodiment, plasma irradiation is performed using fluorocarbon gas in step S22. The fluorocarbon gas is, for example, a fluorine compound such as carbon tetrafluoride (CF ₄ ). In the following description, the fluorocarbon gas is assumed to be carbon tetrafluoride (CF ₄ ). In this case, as shown in Fig. 4, the fluorocarbon gas is irradiated toward the surface portion 131 by CF ₄ plasma 310. Fig. 4 is a diagram showing a state in which the intermediate product is irradiated with CF ₄ plasma 310.

By irradiating the surface portion 131 with the fluorocarbon gas, fluorine compounds by the _CF4 plasma 310 are introduced into the surface portion 131, and the liquid repellency of the surface portion 131 increases. In other words, the wettability of the surface portion 131 of the bank 130 decreases. As a result, a liquid repellent portion 132 is formed on the surface portion 131 (see FIG. 4).

Next, the ink of the first functional layer 140 is applied within the light-emitting region to form the first functional layer 140 located in the region defined by the bank 130 and in contact with the liquid-repellent portion 132 of the surface portion 131 of the bank 130 (step S3). In this embodiment, the first functional layer 140 is composed only of the light-emitting layer 141, so step S3 includes only step S31 for forming the light-emitting layer 141. Step S31 includes the following steps S311 to S313.

Ink in which a high molecular compound and a low molecular compound having luminescent properties are dissolved is applied to the luminescent region by the inkjet method (step S311). The inks applied in step S311 are ink 41R for the red luminescent layer 141R, ink 41G for the green luminescent layer 141G, and ink 41B for the blue luminescent layer 141B.

In the ink 41, the polymeric compound and the low molecular weight compound are dispersed in an organic solvent as a dispersion medium. Here, the concentration of the polymeric compound and the low molecular weight compound in the organic solvent (hereinafter sometimes simply referred to as the solvent) is 0.5 weight percent or more and 10 weight percent or less.

Since the liquid-repellent portion 132 is located on the surface portion 131 of the bank 130, when the ink 41 is applied to the light-emitting region, the ink 41 rises in the light-emitting region as shown in FIG. 5. Therefore, a relatively large amount of ink 41 can be stored in the light-emitting region. FIG. 5 is a cross-sectional view showing an intermediate product in which the ink 41 has accumulated in the light-emitting region.

After the ink 41 has been applied, the substrate 110 on which the ink 41 has been applied is subjected to vacuum drying (step S312). The vacuum drying is performed using a vacuum dryer 210 (see FIG. 19). The vacuum dryer 210 includes a storage section 211 capable of storing the intermediate product and an exhaust pump 212 that reduces the degree of vacuum within the storage section 211.

Vacuum drying is a method of promoting evaporation of the solvent by reducing the pressure inside the housing section 211 housing the substrate 110 with an exhaust pump 212. The ink 41 applied by the inkjet method often uses a solvent with a relatively high boiling point to prevent the solvent from drying at the nozzle. For this reason, vacuum drying is often used to dry the ink quickly.

The conditions for vacuum drying are, for example, an ultimate vacuum of several Pa in the storage section 211 and a holding time of several tens of minutes. However, since the appropriate conditions for the ultimate vacuum and holding time vary depending on the boiling point of the solvent contained in the ink 41 of the light-emitting layer 141, the conditions for vacuum drying are not necessarily limited to an ultimate vacuum of several Pa and a holding time of several tens of minutes.

After the vacuum drying is performed, the ink 41 is heated (step S313). Note that step S313 may be performed as necessary, so step S31 does not necessarily have to include step S313.

As a result, light-emitting layers 141R, 141G, and 141B are formed, as shown in Figure 6. Figure 6 is a diagram showing an intermediate product in which light-emitting layers 141R, 141G, and 141B have been formed. Note that the thicknesses of light-emitting layers 141R, 141G, and 141B shown in Figure 6 correspond to the amounts of ink 41R, 41G, and 41B stored in the light-emitting regions.

Next, the low liquid repellency portion 134 is formed on a part of the surface portion 131 (step S4). In this embodiment, the concentration of the liquid repellent component in a part of the liquid repellency portion 132 is reduced to generate the low liquid repellency portion 134 from that part.

Specifically, in step S4, as shown in Fig. 7, a part of the surface portion 131 is irradiated with oxygen gas ( _O2 ) plasma through a shielding mask 330. Fig. 7 is a diagram showing the intermediate product being irradiated with _O2 plasma 320 through the shielding mask 330. The shielding mask 330 is used to prevent the light-emitting layer 141 from being irradiated with _O2 plasma 320. The part of the surface portion 131 refers to the part of the liquid-repellent portion 132 that occupies the majority of the surface portion 131 other than the part in contact with the light-emitting layer 141.

The portion irradiated with the _O2 plasma 320 is ashed, and the fluorine compound is removed from the portion. This reduces the concentration of fluorine atoms in the portion of the surface portion 131 irradiated with the _O2 plasma 320. That is, the liquid repellency of the portion irradiated with the _O2 plasma 320 decreases, and the wettability increases. As a result, as shown in FIG. 7, the portion of the liquid repellent portion 132 that occupied most of the surface portion 131 and was irradiated with the _O2 plasma 320 becomes the low liquid repellent portion 134 (see FIG. 7). Here, the liquid repellent portion 132 is only the portion of the surface portion 131 that is in contact with the light emitting layer 141.

It should be noted that, by being irradiated with O ₂ plasma 320 , surface 135 of low liquid repellency portion 134 becomes rougher than surface 133 of liquid repellency portion 132 .

Next, a second functional layer 150 is formed in contact with the low liquid repellency portion 134 and covering the light emitting layer 141 (step S5). In this embodiment, step S5 includes step S51 of forming an electrode layer 151 and step S52 of forming a sealing layer 156.

In step S51, an electrode layer 151 is formed so as to cover at least a portion of the bank 130 and the light-emitting layer 141. Here, an ink in which indium-tin oxide nanoparticles are dispersed is applied by an inkjet method, the solvent of the applied ink is dried by a method such as vacuum drying, and the ink is heated to about 200°C, thereby forming the electrode layer 151 as shown in FIG. 8. FIG. 8 shows an intermediate product in which the electrode layer 151 has been formed.

In step S51, the amount of ink to be applied is determined so that the thickness of the electrode layer 151 after the ink has dried will be a predetermined thickness.

In step S52, the ink for the sealing layer 156 is applied to form the sealing layer 156 that covers at least a portion of the bank 130 and the electrode layer 151. Step S52 includes steps S521 to S524.

First, ink containing an epoxy resin material or an acrylic resin material is applied using an inkjet method (step S521).

After the ink is applied, the applied ink is left for a certain period of time (step S522). This forms a layer. Next, the formed layer is leveled to make the layer thickness uniform (step S523).

Next, the uniform layer is irradiated with ultraviolet light to harden the layer (step S524). In step S524, the wavelength of the irradiated ultraviolet light is about 350 nm or more and 400 nm or less. In step S524, a metal halide lamp may be used, or an LED capable of emitting ultraviolet light of a single wavelength may be used. The irradiation amount of the ultraviolet light is, for example, 200 mJ/ ^cm2 or more and 1000 mJ/ ^cm2 or less.

Since the bank 130 has a low liquid repellency portion 134, in step S5, the ink of the second functional layer 150 can be applied uniformly without being repelled by the bank 130.

As a result of step S5, the functional device 100 shown in FIG. 2 is completed.

As described above, according to this embodiment, the functional device 100 includes a bank 130 having a liquid repellent portion 132 and a low liquid repellent portion 134 having lower liquid repellency than the liquid repellent portion 132 on the surface portion 131. The first functional layer 140 is in contact with the liquid repellent portion 132, and the second functional layer 150 is in contact with the low liquid repellent portion 134.

Therefore, when the second functional layer 150 covering the first functional layer 140 is formed using a coating process, the ink of the second functional layer 150 is not repelled by the bank 130. This ensures uniformity in the thickness of the second functional layer 150. This prevents deterioration in the quality of the functional device 100 caused by a decrease in the uniformity of the second functional layer 150. As a result, even when the second functional layer 150 is formed using a coating process, a high-quality functional device 100 can be manufactured. This allows the materials of each layer to be used effectively and ensures high quality.

Furthermore, since the ink of the second functional layer 150 is not repelled by the bank 130, it is easy to form a second functional layer 150 without pinholes. This improves the coverage of the sealing layer 156 of the second functional layer 150, and prevents moisture from penetrating into the first functional layer 140 due to a decrease in the coverage of the sealing layer 156. This ensures the reliability of the functional device 100 over time.

Furthermore, since the bank 130 has a liquid-repellent portion 132, when forming the first functional layer 140, a sufficient amount of ink for the first functional layer 140 can be stored in the area defined by the bank 130. This makes it easier to form the first functional layer 140 with the desired thickness. Also, since there is no need to form a relatively high bank 130 to store the ink for the first functional layer 140, the size of the functional device 100 is not increased, making it easier to form the first functional layer 140 with the desired thickness, and ensuring the quality of the functional device 100. Also, since there is no need to form a relatively high bank 130, the risk of reducing the coverage of the second functional layer 150 is reduced.

By forming the second functional layer 150 using a coating process, the operating energy can be reduced compared to when it is formed using a vacuum process, thereby reducing the cost of manufacturing the functional device 100.

In addition, by forming the second functional layer 150 using a coating process, the functional device 100 can be manufactured at a lower temperature than a vacuum process, so the functional device 100 can be manufactured using substrates with low heat resistance, such as glass substrates and plastic substrates. This makes it possible to manufacture a wider variety of functional devices 100.

In addition, the roughness of the surface 135 of the low liquid repellency section 134 is relatively large. More specifically, the roughness of the surface 135 of the low liquid repellency section 134 is larger than the roughness of the surface 133 of the liquid repellency section 132. This improves the adhesion of the second functional layer 150, which is formed so as to contact the surface 135 of the low liquid repellency section 134, to the surface 135. This improves the sealing performance of the second functional layer 150, thereby preventing moisture from entering the first functional layer 140 from the outside and ensuring the reliability of the functional device 100 over time.

The inside 136 of the bank 130 may be made of the same material as the liquid-repellent portion 132. That is, the inside 136 of the bank 130 may contain a fluorine compound, which is a liquid-repellent component. In this case, the inside 136 has relatively high liquid repellency. In step S21, the bank 130 is formed using ink containing an acrylic resin material containing a fluorine compound. In step S21, when ink containing an acrylic resin material containing a fluorine compound is used, the bank 130 formed by executing step S21 has the entire surface portion 131 occupied by the liquid-repellent portion 132. In other words, the liquid-repellent portion 132 is already formed on the surface portion 131. Therefore, when ink containing an acrylic resin material containing a fluorine compound is used in step S21, step S2 does not include step S22.

In addition, in the embodiment, the functional device 100 does not necessarily have to have a top emission structure.

(Variation 1)
The following describes the first modification, mainly focusing on differences from the above-described embodiment, with reference to Fig. 9A . Fig. 9A is a cross-sectional view of a functional device 100 according to the first modification.

The sealing layer 156 of the functional device 100 according to the first modification is divided into regions defined by the banks 130. Of the layers constituting the functional device 100, the sealing layer 156 accounts for a large portion of the thickness. Therefore, when a deformation stress (e.g., bending stress) is applied to the functional device 100, the stress on the sealing layer 156 becomes large, and the sealing layer 156 may crack. However, if the sealing layer 156 is divided as in the functional device 100 according to the first modification, a stress-relieving effect occurs at that location, making it possible to suppress cracking of the sealing layer 156.

In step S521 of the method for manufacturing the functional device 100 according to the first modification, ink for the sealing layer 156 is applied to a portion of the bank 130 and to an area on the electrode layer 151 that corresponds to the light-emitting area. In other respects, the method for manufacturing the functional device 100 according to the first modification is the same as the method for manufacturing the functional device 100 according to the embodiment.

The functional device 100 according to the first modification provides the same effects as the functional device 100 according to the embodiment.

In addition, in the first modified example, as shown in FIG. 9B, the second functional layer 150 may include an inorganic layer 158 located on the sealing layer 156 in addition to the electrode layer 151 and the sealing layer 156. More specifically, the sealing layer 156 and the inorganic layer 158 may be alternately stacked on the electrode layer 151 and the bank 130. Here, when a combination of the sealing layer 156 and the inorganic layer 158 is defined as one pair, the second functional layer 150 may include N pairs of such combinations. N is an integer of 1 or more. Note that the sealing layer 156 and the inorganic layer 158 have a thinner layer thickness above the bank 130 than above the light-emitting layer 141.

The material of inorganic layer 158 is an inorganic compound.

As shown in FIG. 9B, when the functional device 100 has an inorganic layer 158, step S52 includes step S525 in addition to steps S521 to S524. Step S525 is a step of forming the inorganic layer 158 on the sealing layer 156 by an inkjet method. Furthermore, a sealing layer 156 is formed on the inorganic layer 158, and an inorganic layer 158 is formed on the formed sealing layer 156, and this is repeated until N pairs of sealing layers 156 and inorganic layers 158 are formed.

As shown in FIG. 9B, when the second functional layer 150 has an inorganic layer 158, the moisture permeability of the second functional layer 150 can be reduced. This makes it possible to more reliably ensure the reliability of the functional device 100 over time.

As shown in FIG. 9B, when the second functional layer 150 has multiple pairs of sealing layers 156 and inorganic layers 158, they do not necessarily need to be separated into regions defined by the banks 130, and may be connected.

(Variation 2)
The following describes the second modification, focusing mainly on the differences from the above-described embodiment, with reference to Fig. 10. Fig. 10 is a cross-sectional view of a functional device 100 according to the second modification.

The first functional layer 140 of the functional device 100 according to the second modification is composed of a light-emitting layer 141, a hole injection layer 142, a hole transport layer 143, and an electron injection layer 144.

<Hole injection layer 142>
The hole injection layer 142 is located on the electrode layer 120. The hole injection layer 142 is a layer that injects holes into the light emitting layer 141. The material of the hole injection layer 142 is an organic material such as a polythiophene-based material. Specifically, the material of the hole injection layer 142 is poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), or so-called PEDOT:PSS. PEDOT:PSS is a conductive polymer material.

<Hole transport layer 143>
The hole transport layer 143 is formed on the hole injection layer 142 so as to cover the hole injection layer 142. The hole transport layer 143 is a layer that transports holes injected by the hole injection layer 142 to the light emitting layer 141. The hole transport layer 143 is also a layer that prevents electrons injected by the electron injection layer 144 from entering the hole injection layer 142. The material of the hole transport layer 143 is, for example, poly(9,9-dioctylfluorene-co-N-(4-butylphenyl)-diphenylamine), so-called TFB.

<Electron Injection Layer 144>
The electron injection layer 144 is formed so as to cover the light emitting layer 141. The material of the electron injection layer 144 is a transparent oxide semiconductor such as zinc oxide.

Next, a method for manufacturing the functional device 100 according to the second modification will be described.

Step S3 includes steps S301, S302, and S321 in addition to step S31 described above. Step S301 is a step of forming a hole injection layer 142 in the light-emitting region after step S2 is completed. Step S302 is a step of forming a hole transport layer 143 so as to cover the hole injection layer 142 after step S301 is completed. Step S321 is a step of forming an electron injection layer 144 so as to cover the light-emitting layer 141 after step S31 is completed.

In steps S301, S302, and S321, the ink for each layer is applied to the light-emitting area, the solvent in the applied ink is dried by a method such as vacuum drying, and the substrate 110 is heated as necessary. This forms the hole injection layer 142, the hole transport layer 143, and the electron injection layer 144.

In the second modification, in step S4, _O2 plasma 320 is irradiated through a shielding mask 330 to prevent the O2 _plasma 320 from being irradiated onto the light-emitting layer 141, the hole injection layer 142, the hole transport layer 143, and the electron injection layer 144.

Otherwise, the manufacturing method of the functional device 100 according to the second modification is the same as the manufacturing method of the functional device 100 according to the embodiment. Note that in the second modification, by performing step S4, the portions of the surface portion 131 other than the portions in contact with the light-emitting layer 141, the hole injection layer 142, the hole transport layer 143, and the electron injection layer 144 become the low liquid-repellent portion 134.

The functional device 100 according to the second modification example provides the same effects as the functional device 100 according to the embodiment.

(Variation 3)
The third modification will be described below, focusing mainly on the differences from the above-described embodiment, with reference to Fig. 11. Fig. 11 is a cross-sectional view of a functional device 100 according to the third modification.

The functional device 100 according to the third modification is an organic transistor device. The functional device 100 shown in FIG. 11 is an organic transistor device having a bottom gate structure and a top contact structure.

The electrode layer 120 of the functional device 100 is composed of a gate electrode layer 121 and a gate insulating layer 122. The first functional layer 140 of the functional device 100 is composed of an organic semiconductor layer 145. The second functional layer 150 is composed of an electrode layer 151 and a protective layer 157, and the electrode layer 151 is composed of a source electrode 152 and a drain electrode 153.

<Gate electrode layer 121>
A gate electrode layer 121 is located on the substrate 110, and the material of the gate electrode layer 121 is, for example, molybdenum.

<Gate insulating layer 122>
The gate insulating layer 122 is a layer that covers the gate electrode layer 121, and the material of the gate insulating layer 122 is, for example, an olefin polymer.

<Organic semiconductor layer 145>
The organic semiconductor layer 145 covers the gate insulating layer 122, and is located in a region defined by the bank 130 so as to contact the liquid repellent portion 132. The material of the organic semiconductor layer 145 is pentacene. In addition to pentacene, the material of the organic semiconductor layer 145 may be a low molecular weight organic semiconductor material such as tetracene and a phthalocyanine-based compound, a high molecular weight organic semiconductor material such as polythiophene and polyphenylenevinylene, or a carbon nanotube.

<Source Electrode 152 and Drain Electrode 153>
The source electrode 152 and the drain electrode 153 are electrodes for forming a channel. The source electrode 152 and the drain electrode 153 are located directly above the organic semiconductor layer 145 so as to cover at least a part of the bank 130 and the organic semiconductor layer 145. The source electrode 152 and the drain electrode 153 are arranged to face each other with a certain distance (for example, about several μm). Note that the functional device 100 exhibits semiconductor characteristics by carriers flowing between the source electrode 152 and the drain electrode 153. In order to ensure a long carrier path, the source electrode 152 and the drain electrode 153 may be formed in a comb-like shape. The material of the source electrode 152 and the drain electrode 153 is, for example, gold.

An organic transistor device with a top-contact structure such as that of variant example 3 has a source electrode 152 and a drain electrode 153 located directly above the organic semiconductor layer 145, and therefore exhibits stable semiconductor characteristics.

The protective layer 157 covers at least a portion of the bank 130, the source electrode 152, the drain electrode 153, and the organic semiconductor layer 145. A contact hole 400 is formed in the protective layer 157. The contact hole 400 penetrates the protective layer 157 from the end of the protective layer 157 farthest from the substrate 110 to the drain electrode 153. The formation of the contact hole 400 allows the drain electrode 153 to be electrically connected to an electrode of another functional device. This allows, for example, the drain electrode 153 of the functional device 100 according to the third modification to be electrically connected to an electrode of the organic EL device, and the light emission of the organic EL device to be controlled by the functional device 100 according to the third modification.

In the third modification, the inside 136 of the bank 130 is made of the same material as the liquid-repellent portion 132. The material of the inside 136 of the bank 130 and the liquid-repellent portion 132 contains a photosensitive resin material and a fluorine compound, which is a liquid-repellent component. Therefore, the inside 136 has a relatively high liquid-repellency.

<Method of Manufacturing Functional Device 100>
The manufacturing method of the functional device 100 according to the third variant includes the above-mentioned steps S1 to S5, but differs in terms of the differences between an organic EL device and an organic transistor device, and the differences in the materials that make up the interior 136.

In step S1 of the third modification, molybdenum is used as the material, and a layer is formed on the substrate 110 by sputtering, and the layer is patterned into a desired pattern by photolithography to form the gate electrode layer 121. Furthermore, an olefin polymer is applied to the substrate 110 and the gate electrode layer 121 by spin coating to form a layer, and the layer is heated to form the gate insulating layer 122.

Step S2 in variant 3 is the same as step S2 in the embodiment, except that a bank 130 having relatively high liquid repellency is formed using ink containing a photosensitive acrylic resin material containing a fluorine compound, and step S22 is not included.

In step S3 of the third modification, an ink produced by dissolving pentacene in an organic solvent is applied by an inkjet method to the area defined by the bank 130, and the applied ink is vacuum dried and heated to form the organic semiconductor layer 145.

Step S4 in variant 3 is the same as step S4 in the embodiment.

In step S5 of the third modification, first, a source electrode 152 and a drain electrode 153 are formed in contact with the low liquid repellency portion 134 and covering the organic semiconductor layer 145. More specifically, the source electrode 152 and the drain electrode 153 are formed by applying ink in which gold nanoparticles are dispersed to a part of the low liquid repellency portion 134 and the organic semiconductor layer 145 by an inkjet method. Here, the source electrode 152 and the drain electrode 153 are formed to be spaced apart from each other by a certain distance and to face each other. Next, a protective layer 157 is formed to cover the source electrode 152, the drain electrode 153, and the low liquid repellency portion 134. Next, a contact hole 400 is formed in the protective layer 157 to expose the drain electrode 153.

The functional device 100 according to the third modification provides the same effect as the functional device 100 according to the embodiment.

Note that the contact hole 400 may not be formed in the protective layer 157. In that case, the contact hole 400 is not formed in step S5.

(Other Modifications)
The liquid-repellent component may be a compound containing fluorine atoms or silicon atoms. That is, a silicon compound may be used as the liquid-repellent component instead of a fluorine compound. In this case, the concentration of silicon atoms in the liquid-repellent portion 132 is higher than the concentration of silicon atoms in the low liquid-repellent portion 134. Specifically, the concentration of fluorine atoms in the liquid-repellent portion 132 is 5 atom% or more and 10 atom% or less, and the concentration of fluorine atoms in the low liquid-repellent portion 134 is 0 atom% or more and less than 5 atom%. Even when a silicon compound is used as the liquid-repellent component instead of a fluorine compound, the contact angle of the liquid-repellent portion 132 with respect to the ink of the first functional layer 140 is 20 degrees or more and 70 degrees or less, preferably 30 degrees or more and 60 degrees or less. In the same case, the contact angle of the low liquid-repellent portion 134 with respect to the ink of the second functional layer 150 is 0 degrees or more and 30 degrees or less, preferably 0 degrees or more and 20 degrees or less.

Even if the liquid-repellent component contained in the liquid-repellent portion 132 and the low liquid-repellent portion 134 is a silicon compound, the same effect can be obtained as when the liquid-repellent component is a fluorine compound.

In step S4, if it is possible to reduce the concentration of the liquid-repellent component contained in the liquid-repellent portion 132 and form a low-liquid-repellent portion 134 from a portion of the liquid-repellent portion 132, the following processes (A) to (C) may be performed instead of plasma irradiation.

(A) In step S4, the substrate 110 on which the bank 130 and the first functional layer 140 are formed may be accommodated in the accommodation section 211 of the vacuum dryer 210 (see FIG. 19), and the degree of vacuum in the accommodation section 211 may be reduced while the bank 130 is heated. For example, the degree of vacuum in the accommodation section 211 may be reduced to 10 Pa.

The fluorine compound by the _CF4 plasma 310 is introduced into the surface portion 131 by bonding with the carbon atoms of the surface portion 131. The bond between the fluorine compound introduced into the surface portion 131 of the bank 130 by the _CF4 plasma 310 and the carbon atoms of the surface portion 131 is weak and unstable. Therefore, the fluorine compound is gradually released from the surface portion 131 (lyophobic portion 132) over time. This release phenomenon can be accelerated by heating the bank 130 and reducing the pressure of the atmosphere around the bank 130.

(B) In step S4, a portion of the liquid-repellent portion 132 may be irradiated with ultraviolet light.

(C) In step S4, a part of the liquid repellent portion 132 may be removed to expose the interior 136 of the bank 130. This causes the interior 136, which has low liquid repellency, to be located on the surface portion 131 of the bank 130, and a portion with low liquid repellency is formed on the surface portion 131. In other words, the low liquid repellency portion 134 is formed on the surface portion 131.

When removing part of the liquid-repellent portion 132, sandblasting, mechanical polishing, etc. may be performed.

In addition, in step S4, whether the treatment (B) or (C) is performed, the surface roughness of the surface 135 of the low liquid repellency section 134 becomes greater than the surface roughness of the surface 133 of the liquid repellency section 132. In particular, the surface roughness changes significantly by performing the treatment (C). This increases the adhesion of the second functional layer 150 to the surface 135, improving the sealing performance of the second functional layer 150, thereby preventing the intrusion of moisture from the outside and ensuring the reliability of the functional device 100 over time.

In step S4, the processes (A) and (C) are performed on the assumption that the liquid repellency of the interior 136 of the bank 130 is relatively low. If, as in the embodiment, an ink containing a resin material that does not contain a liquid repellent component such as a fluorine compound or a silicon compound is used as the material of the bank 130 in step S21, the liquid repellency of the interior 136 of the bank 130 will be relatively low.

In addition, in step S4, the first functional layer 140 may be irradiated with plasma or ultraviolet light at a low intensity so as not to damage the first functional layer 140. In this case, the process of step S4 is performed without using the shielding mask 330.

In step S211, the photosensitive resin material may be applied by a different application process, slit coating. In this case, the scanning speed of the slit coating, which is an application condition, is adjusted according to the required height of the bank 130.

Before irradiating the surface portion 131 of the bank 130 with the _CF4 plasma 310, the electrode layer 120 may be ashed using _O2 plasma or atmospheric pressure plasma. Ashing the electrode layer 120 has the following two advantages.

(I) When ashing is performed with _O2 plasma or atmospheric pressure plasma, the number of carbon atoms on the electrode layer 120 becomes extremely small. The fluorine compounds produced by the _CF4 plasma 310 are introduced into the surface portion 131 by bonding with the carbon atoms in the surface portion 131. Therefore, by ashing the electrode layer 120, the fluorine compounds are less likely to be introduced into the surface of the electrode layer 120, but on the other hand, they are more likely to be introduced into the surface portion 131 of the bank 130 made of a resin material.

(II) When a fluorine compound is introduced into the surface of the electrode layer 120, the liquid repellency of the surface of the electrode layer 120 increases, and the ink of the first functional layer 140 is repelled when applied to the surface of the electrode layer 120, making it impossible to form a highly uniform light emitting layer 141. In other words, by ashing the electrode layer 120 to reduce the number of carbon atoms on the surface of the electrode layer 120, even if irradiation with _CF4 plasma 310 is performed, an increase in the liquid repellency of the surface of the electrode layer 120 can be suppressed, and a highly uniform first functional layer 140 can be formed.

The functional device 100 may be a quantum dot light-emitting device. In this case, the material of the light-emitting layer 141 is an inorganic compound in which a cadmium-selenium compound has been turned into a quantum dot shape. The quantum dot material emits light in different colors depending on the particle size, with larger particles emitting more red light. Thus, the inks 41R, 41G, and 41B of the red light-emitting layer 141R, green light-emitting layer 141G, and blue light-emitting layer 141B each contain materials (i.e., quantum dot materials) with different particle sizes.

In step S311, the ink 41 in which the inorganic compound in the quantum dot state is dispersed is applied by a coating process such as an inkjet method. Here, the ink 41 contains a cadmium-selenium inorganic material. In these inks 41, the cadmium-selenium inorganic material is dispersed in an organic solvent as a dispersion medium, and the concentration of the material is 0.5 weight percent or more and 10 weight percent or less.

The ink 41 for the light-emitting layer 141 may be an ink in which any of the following materials is dispersed: indium-phosphorus, copper-indium-sulfur, silver-indium-sulfur, or inorganic material having a perovskite structure.

Functional device 100 may also be a color conversion filter device that converts the emitted color. In this case, the first functional layer 140 of functional device 100 includes a layer formed of a quantum dot material. The layer formed of the quantum dot material can be formed by an inkjet method.

Functional device 100 may also be a sensor device. In this case, first functional layer 140 of functional device 100 includes a layer formed of a piezoelectric material. It goes without saying that when functional device 100 is a sensor device, functional device 100 has electrode layer 151 that functions as an electrode. Electrode layer 151 and the layer formed of a piezoelectric material can be formed by an inkjet method.

In the embodiment, variant 1, and variant 2, the sealing layer 156 may be formed after forming a thin film of silicon nitride on the electrode layer 151.

The first functional layer 140 is not limited to the layers shown in the embodiment and modifications 1 to 3, but may include one or more layers selected from the light-emitting layer 141, the hole injection layer 142, the hole transport layer 143, the electron injection layer 144, and the organic semiconductor layer 145.

The second functional layer 150 is not limited to the layers shown in the embodiment and modified examples 1 to 3, but may include one or more layers selected from the electrode layer 151, the sealing layer 156, and the protective layer 157.

Example 1
The inventors have manufactured a functional device 100, which is an organic EL device, by any of the manufacturing methods of the above-described embodiment, modifications 1 to 3, and other modifications. Hereinafter, the manufacture of the functional device 100 (i.e., an organic EL device) will be described with reference to FIGS. 12 to 15.

First, a 0.5 mm thick sheet of glass manufactured by AGC was prepared as the substrate 110. A layer was then formed on the substrate 110 using a silver-palladium-copper alloy as the material by sputtering, and the layer was then patterned into the desired pattern by photolithography to form the electrode layer 120.

Next, an ink containing a photosensitive acrylic resin material made by AGC, which is an acrylic resin material containing a fluorine compound, is applied onto the substrate 110 by spin coating, the applied ink is pre-baked at 100°C to form a layer, and the layer is irradiated with ultraviolet light having a wavelength of 365 nm to form a rectangular pattern, followed by post-baking. This results in the formation of the bank 130. In Example 1, the bank 130 is formed to a height of 1 μm. As a result, the intermediate product shown in FIG. 12 is formed. FIG. 12 is a cross-sectional view showing the intermediate product in a state in which the electrode layer 120 and the bank 130 are formed on the substrate 110.

In the intermediate product shown in FIG. 12, fluorine compounds were segregated on the surface portion 131 of the bank 130. The surface portion 131 had high liquid repellency and low wettability. In other words, it can be said that the surface portion 131 is occupied by the liquid repellent portion 132. The contact angle of the liquid repellent portion 132 of the bank 130 with the ink 41R is 20 degrees or more and 70 degrees or less, preferably 30 degrees or more and 60 degrees or less. The interior 136 has relatively high liquid repellency.

Next, ink 41R, which is the material for the red light-emitting layer 141R, was applied by the inkjet method to the light-emitting area, which is the area defined by the bank 130.

The intermediate product was then dried by vacuum drying. More specifically, the pressure of the atmosphere surrounding the ink 41R was reduced to dry the solvent of the applied ink 41R. As a result, a red light-emitting layer 141R was formed, as shown in Figure 13. Figure 13 is a cross-sectional view showing the intermediate product in which the red light-emitting layer 141R has been formed.

FIG. 14 is a diagram showing the intermediate product being irradiated with _O2 plasma through a shielding mask.

After the red light-emitting layer 141R was formed, the bank 130 was irradiated with _O2 plasma 320. At this time, the _O2 plasma 320 was irradiated through a shielding mask 330 so that the red light-emitting layer 141R was not irradiated with the _O2 plasma 320. This treatment removes fluorine compounds from the surface portion 131 of the bank 130 to which the red light-emitting layer 141R is not in contact, so that the density of fluorine atoms is reduced and the concentration of fluorine atoms is reduced compared to the surface portion 131 of the bank 130 to which the red light-emitting layer 141R is in contact. As a result, as shown in FIG. 14, the portion of the liquid-repellent portion 132 that is not in contact with the red light-emitting layer 141R becomes the low liquid-repellent portion 134. The liquid-repellent portion 132 is only the portion of the surface portion 131 that is in contact with the red light-emitting layer 141R. The contact angle of the low liquid-repellent portion 134 with respect to the ink of the second functional layer 150 is 0 degrees or more and 30 degrees or less, preferably 0 degrees or more and 20 degrees or less.

Next, ink in which indium-tin oxide (ITO) nanoparticles are dispersed is applied to a portion of the bank 130 and the red light-emitting layer 141R by the inkjet method, the solvent of the applied ink is evaporated by vacuum drying, and the ink is heated to about 200°C. This forms an electrode layer 151 that covers at least a portion of the bank 130 and the red light-emitting layer 141R.

Next, ink containing a photosensitive acrylic resin material (i.e., the ink of the sealing layer 156) was applied to a part of the bank 130 and the electrode layer 151 by the inkjet method. The height (i.e., thickness) of the ink when applied was about 4 μm. Then, using an LED lamp, ultraviolet light with a wavelength of 395 nm was irradiated onto the ink of the sealing layer 156 by adjusting the irradiation time so that the irradiation amount was 1000 mJ/ ^cm2 , and the acrylic resin material was cured. As a result, the sealing layer 156 was formed, and the functional device 100, which is an organic EL device, was completed as shown in FIG. 15. FIG. 15 is a cross-sectional view showing the structure of the functional device 100 according to the first embodiment.

By configuring the device structure of the functional device 100 as shown in any of the above-described embodiments, modifications 1 to 3, and other modifications, it was possible to form a highly uniform electrode layer 151 and sealing layer 156 using the inkjet method.

Therefore, even when the first functional layer 140 as well as the second functional layer 150 are formed using a coating process, it can be said that the quality of the manufactured functional device 100 can be ensured. In addition, compared to when the functional layer 140 is formed using a vacuum process, it can be said that the cost of manufacturing the functional device 100 can be reduced and the functional device 100 can be manufactured at a relatively low temperature. The fact that the functional device 100 can be manufactured at a low temperature means that a substrate with low heat resistance, such as a glass substrate or a plastic substrate, can be used as the substrate 110, making it possible to make the substrate 110 more flexible.

Example 2
The inventors have manufactured a functional device 100, which is an organic EL device, by a method among any of the manufacturing methods of the above-described embodiment, modifications 1 to 3, and other modifications, which is different from Example 1. Hereinafter, the manufacturing method of the functional device 100 (i.e., the organic EL device) will be described, mainly focusing on the points different from Example 1, with reference to Figs. 16 to 20 .

First, a substrate 110 was prepared, and an electrode layer 120 was formed on the substrate 110.

Next, an ink containing a photosensitive acrylic resin material manufactured by Nissan Chemical was applied onto the substrate 110 by spin coating, the applied ink was pre-baked at 100°C to form a layer, and the layer was irradiated with ultraviolet light having a wavelength of 365 nm to form a rectangular pattern, followed by post-baking. This resulted in the formation of the bank 130. In Example 2, the bank 130 was formed to a height of 1 μm. As a result, the intermediate product shown in FIG. 16 was formed. FIG. 16 is a cross-sectional view showing the intermediate product in a state in which the electrode layer 120 and the bank 130 have been formed on the substrate 110.

The ink used to form the bank 130 mainly contains an acrylic resin material, and the formed bank 130 has relatively low liquid repellency both on the surface portion 131 and in the interior portion 136.

Next, the bank 130 was irradiated with _O2 plasma 320. After that, the bank 130 was irradiated with _CF4 plasma 310 to introduce a fluorine compound into the surface portion 131 of the bank 130. Fig. 17 is a diagram showing the intermediate product being irradiated with _CF4 plasma 310. By irradiating with _CF4 plasma 310, the concentration of fluorine atoms in the surface portion 131 is increased, and the liquid repellency of most of the surface portion 131 is increased. That is, as shown in Fig. 17, a liquid repellent portion 132 is formed on the surface portion 131.

Next, ink 41R, which is the material for the red light-emitting layer 141R, was applied by inkjet printing to the light-emitting region defined by the bank 130, and the applied ink 41R was vacuum-dried. As a result, the red light-emitting layer 141R was formed, as shown in Figure 18. Figure 18 is a cross-sectional view showing the intermediate product in which the red light-emitting layer 141R has been formed.

Next, as shown in FIG. 19, the intermediate product of FIG. 17 was placed in the storage section 211 of the vacuum dryer 210. FIG. 19 is a cross-sectional view showing the intermediate product placed in the vacuum dryer 210. The vacuum dryer 210 is equipped with the storage section 211 and an exhaust pump 212.

After the intermediate product was placed in the storage section 211, the air in the storage section 211 was evacuated using the exhaust pump 212 to reduce the degree of vacuum in the storage section 211, and the bank 130 was heated to 60 degrees.

The fluorine compound introduced by the _CF4 plasma 310 is introduced into the surface portion 131 by bonding with the carbon atoms of the surface portion 131. The bond between the fluorine compound introduced into the surface portion 131 of the bank 130 by the _CF4 plasma 310 and the carbon atoms of the surface portion 131 is weak and unstable. For this reason, the fluorine compound is gradually released from the surface portion 131 (lyophobic portion 132) over time. This release phenomenon was accelerated by heating the bank 130 and reducing the pressure of the atmosphere around the bank 130.

As a result, the fluorine compound is removed from the portion of the liquid-repellent portion 132 that is not in contact with the red light-emitting layer 141R, and the density of fluorine atoms in that portion decreases. This reduces the liquid repellency of that portion and increases its wettability. That is, as shown in FIG. 19, that portion of the surface portion 131 becomes a low liquid repellency portion 134.

On the other hand, the fluorine compound is not removed from the portion of the liquid repellent portion 132 that is in contact with the red light-emitting layer 141R.

Next, the electrode layer 151 and the sealing layer 156 were formed in the same manner as in Example 1. As a result, the functional device 100, which is an organic EL device, was completed as shown in FIG. 20. FIG. 20 is a cross-sectional view showing the structure of the functional device according to Example 2.

Therefore, by configuring the device structure of the functional device 100 to be any of the device structures of the above-mentioned embodiment, variants 1 to 3, and other variants, it was possible to form a highly uniform electrode layer 151 and sealing layer 156 using the inkjet method.

Therefore, even when the first functional layer 140 as well as the second functional layer 150 are formed using a coating process, it can be said that the quality of the manufactured functional device 100 can be ensured. In addition, it can be said that the functional device 100 can be manufactured at low cost and at a relatively low temperature compared to when it is formed using a vacuum process. The ability to manufacture the functional device 100 at low temperature means that the substrate 110 can be made flexible.

Example 3
The inventors manufactured the functional device 100, which is a quantum dot light-emitting device, by the manufacturing method of any of the above-mentioned embodiment, modifications 1 to 3, and other modifications. Hereinafter, the manufacturing method of the functional device 100 (i.e., the quantum dot light-emitting device) will be described, focusing mainly on the points different from Example 1.

The quantum dot luminescent material used is an inorganic cadmium-selenium compound with a particle size of several tens of nanometers.

In the manufacture of quantum dot light-emitting devices, an ink with particle sizes of several tens of nanometers and a cadmium-selenium-based inorganic compound dispersed in an aromatic organic solvent was applied to the light-emitting area using the inkjet method to form a light-emitting layer.

Apart from the difference in the material of the light-emitting layer 141, the functional device 100, which is a quantum dot light-emitting device, was formed using the same manufacturing process as in Example 1.

Therefore, according to the above-mentioned embodiment, variants 1 to 3, and any of the other variants, it can be said that not only organic EL devices but also quantum dot light-emitting devices can be manufactured in the same manner.

Example 4
The inventors have manufactured a functional device 100, which is an organic transistor device, by any one of the manufacturing methods of the above-described embodiment, modifications 1 to 3, and other modifications.

First, a 0.5 mm thick glass sheet manufactured by AGC was prepared as the substrate 110. Then, a layer was formed on the substrate 110 using molybdenum as the material by a sputtering method, and the layer was patterned into a desired pattern by a photolithography method to form the gate electrode layer 121.

Next, an olefin polymer was applied to the substrate 110 and the gate electrode layer 121 by spin coating to form a layer, and the layer was hardened by heating at 130 degrees. This resulted in the formation of a gate insulating layer 122 that covers the gate electrode layer 121.

Next, an ink containing a photosensitive acrylic resin material made by AGC that contains a fluorine compound is applied onto the substrate 110 by spin coating, the applied ink is pre-baked at 100°C to form a layer, and the layer is irradiated with ultraviolet light having a wavelength of 365 nm to form a rectangular pattern, followed by post-baking. This results in the formation of the bank 130. In Example 4, the bank 130 is formed so that its height is 0.3 μm or more and 1 μm or less.

The fluorine compound was segregated on the surface portion 131 of the bank 130, and the surface portion 131 had high liquid repellency and low wettability. In other words, the surface portion 131 was occupied by the liquid repellent portion 132. The contact angle of the liquid repellent portion 132 with respect to the ink of the organic semiconductor layer 145 was 20 degrees or more and 70 degrees or less, and preferably 30 degrees or more and 60 degrees or less. The interior 136 had relatively high liquid repellency.

Next, an ink made by dissolving pentacene in an organic solvent was applied to the area defined by the bank 130 using an inkjet method.

Then, the solvent in the applied ink was dried by vacuum drying, and the ink was heated to 100°C. As a result, an organic semiconductor layer 145 was formed.

Next, the bank 130 was irradiated with _O2 plasma 320 in the same manner as in Example 1. As a result, the fluorine compound was removed from the portion of the liquid repellent portion 132 of the bank 130 that was not in contact with the organic semiconductor layer 145, reducing the liquid repellency of that portion and increasing the wettability. In other words, that portion of the surface portion 131 became the low liquid repellent portion 134. The contact angle of the low liquid repellent portion 134 with respect to the ink of the second functional layer 150 is 0 degrees or more and 30 degrees or less, preferably 0 degrees or more and 20 degrees or less.

Next, ink in which gold nanoparticles are dispersed is applied to a portion of the low liquid repellency portion 134 and the organic semiconductor layer 145 by the inkjet method to form the source electrode 152 and the drain electrode 153. Here, the source electrode 152 and the drain electrode 153 are formed to be spaced apart from each other at a certain distance and to face each other.

Next, a protective layer 157 was formed to cover the source electrode 152, the drain electrode 153, and the low liquid repellency portion 134. Then, a contact hole 400 was formed to expose the drain electrode 153. As a result, the functional device 100, which is an organic transistor device, shown in FIG. 11 was completed.

Therefore, it can be said that organic transistor devices can be similarly manufactured according to the above-described embodiment, variants 1 to 3, and any of the other variants.

The functional devices and manufacturing methods for functional devices disclosed herein can be suitably used for functional devices such as organic EL devices, quantum dot light-emitting devices, color conversion filter devices, organic transistor devices, and sensor devices.

LIST OF SYMBOLS 1 organic EL device 10 TFT panel 12 anode 13 hole injection layer 14 hole transport layer 15 organic light emitting layer 16 bank 18 electron injection layer 20 transparent cathode 22 transparent sealing film 70 light 100 functional device 110 substrate 120 electrode layer 121 gate electrode layer 122 gate insulating layer 130 bank 131 surface portion 132 liquid repellent portion 133 surface of liquid repellent portion 134 low liquid repellent portion 135 surface of low liquid repellent portion 136 inside 140 first functional layer 141 light emitting layer 141R red light emitting layer 141G green light emitting layer 141B blue light emitting layer 41 ink 41R red light emitting ink 41G red/green light emitting ink 41B blue light emitting ink 142 hole injection layer 143 Hole transport layer 144 Electron injection layer 145 Organic semiconductor layer 150 Second functional layer 151 Electrode layer 152 Source electrode 153 Drain electrode 156 Sealing layer 157 Protective layer 158 Inorganic layer 210 Vacuum dryer 211 Storage section 212 Exhaust pump 310 _CF4 plasma 320 _O2 plasma 330 Shielding mask 400 Contact hole

Claims (19)

a bank having a liquid repellent portion and a less liquid repellent portion having a lower liquid repellency than the liquid repellent portion on a surface thereof;
a first functional layer located in an area defined by the bank and in contact with the liquid repellent portion;
a second functional layer that contacts the low liquid repellency portion and covers the first functional layer;
Equipped with
The surface portion includes a side surface portion of the bank, and the low liquid repellency portion is provided on a part of the side surface portion . the concentration of fluorine atoms in the liquid repellent portion is higher than the concentration of fluorine atoms in the low liquid repellent portion;
The functional device according to claim 1 . The concentration of fluorine atoms in the liquid repellent portion is 5 atom % or more and 10 atom % or less,
The concentration of fluorine atoms in the low liquid repellency portion is equal to or greater than 0 atom % and less than 5 atom %.
The functional device according to claim 2 . the concentration of silicon atoms in the liquid repellent portion is higher than the concentration of silicon atoms in the low liquid repellent portion;
The functional device according to claim 1 . The concentration of silicon atoms in the liquid repellent portion is 5 atom % or more and 10 atom % or less,
The concentration of silicon atoms in the low liquid repellency portion is equal to or greater than 0 atom % and less than 5 atom %.
The functional device according to claim 4 . a contact angle of the liquid repellent portion with respect to ink, which is a material of the first functional layer, is equal to or greater than 20 degrees and equal to or less than 70 degrees;
a contact angle of the low liquid repellency portion with respect to ink, which is a material of the second functional layer, is equal to or greater than 0 degrees and equal to or less than 30 degrees;
The functional device according to claim 1 . The surface roughness of the low liquid repellency portion is greater than the surface roughness of the liquid repellency portion.
A functional device according to any one of claims 1 to 6. The first functional layer includes one or more layers selected from the group consisting of a light-emitting layer, a hole-injection layer, a hole-transport layer, an electron-injection layer, and an organic semiconductor layer.
A functional device according to any one of claims 1 to 7. The second functional layer includes one or more layers selected from the group consisting of an electrode layer, a sealing layer, and a protective layer.
A functional device according to any one of claims 1 to 8. a boundary between the liquid repellent portion and the low liquid repellent portion is located between the first functional layer and the second functional layer;
A functional device according to any one of claims 1 to 9. forming a bank on a substrate;
forming a first functional layer located in an area defined by the bank and in contact with a liquid repellent portion of a surface portion of the bank;
forming a low liquid repellency portion having a liquid repellency relatively lower than that of the liquid repellency portion on a part of a side surface portion of the bank included in the surface portion ;
forming a second functional layer in contact with the low liquid repellency portion and covering the first functional layer;
A manufacturing method of a functional device comprising: the liquid repellent portion contains a liquid repellent component containing a fluorine atom or a silicon atom,
the step of forming the low liquid-repellent portion is a step of generating the low liquid-repellent portion from a part of the liquid-repellent portion by reducing a concentration of a liquid-repellent component contained in the liquid-repellent portion;
The method for manufacturing the functional device according to claim 11 . The step of forming the low liquid repellency portion is a step of irradiating a part of the liquid repellency portion with plasma.
The method for manufacturing the functional device according to claim 12 . The step of forming the low liquid repellency portion is a step of irradiating a part of the liquid repellency portion with ultraviolet light.
The method for manufacturing the functional device according to claim 12 . the step of forming the bank includes a step of forming the liquid repellent portion on the surface portion,
the step of forming the low liquid repellency portion is a step of accommodating the substrate on which the bank and the first functional layer are formed in an accommodation portion, heating the bank, and reducing the degree of vacuum in the accommodation portion;
The method for manufacturing the functional device according to claim 12 . the step of forming the bank includes a step of forming the liquid repellent portion on the surface portion,
the step of forming the low liquid repellency portion is a step of removing a part of the liquid repellency portion to expose the inside of the bank;
The method for manufacturing the functional device according to claim 11 . The step of forming the low liquid repellency portion is a step of removing a part of the liquid repellency portion by sandblasting.
A method for manufacturing the functional device according to claim 16 . The step of forming the low liquid repellency portion is a step of removing a part of the liquid repellency portion by mechanical polishing.
A method for manufacturing the functional device according to claim 16 . the step of forming the second functional layer is a step of forming the second functional layer such that a boundary between the liquid repellent portion and the low liquid repellent portion is located between the first functional layer and the second functional layer;
A method for manufacturing the functional device according to any one of claims 11 to 18.

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