JP2020204759A - Color conversion device, micro led display panel, manufacturing method of color conversion device, and manufacturing method of micro-led display panel - Google Patents

Abstract

To provide a color conversion device with a functional film such as a light-emitting layer, and the like which can be formed by using an inkjet method even when the distance between the regions surrounded by a partition wall is narrow while achieving both suppression of deterioration of light emission characteristics and cost reduction.SOLUTION: A color conversion device 20 includes: a substrate 22; a light-emitting layer 21 containing a luminescent material located over the substrate 22; a first partition wall 23 defining a light-emitting region where the light-emitting layer 21 emits light, which is in contact with the light-emitting layer 21; and a second partition wall 24 defining a forming area where a light emitting layer 21 is formed, which is in contact with the light-emitting layer 21. The contact area between the light-emitting layer 21 and the first partition wall 23 is larger than the contact area between the light-emitting layer 21 and the second partition wall 24.SELECTED DRAWING: Figure 3B

Description

The present disclosure relates to a color conversion device, a micro LED display panel, a method for manufacturing a color conversion device, and a method for manufacturing a micro LED display panel.

As a next-generation display panel, the development of a quantum dot display panel having a light emitting layer made of a quantum dot material is underway. Quantum dots are special semiconductors with a diameter of 2 to 10 nanometers (10 to 50 atoms) and a very small size. Such a minute-sized substance has properties different from those of a normal substance. For example, quantum dots can control the bandgap simply by changing the particle size. Further, since the emission peak wavelength of the quantum dot depends on the band gap, the emission peak wavelength of the quantum dot can be adjusted very precisely. That is, the emission peak wavelength of the quantum dot can be changed only by changing the particle size. Specifically, the emission peak wavelength of the quantum dot shifts to the shorter wavelength side as the particle size decreases, and shifts to the longer wavelength side as the particle size increases. Further, the emission spectrum of the quantum dot has a steep peak, and the half width of the emission peak wavelength of the quantum dot is very small, which is several tens of nanometers or less.

Therefore, by using the quantum dot material as the material of the red light emitting layer, the green light light emitting layer, and the blue light emitting layer, the half-value width of each emission peak wavelength of the red light, the green light, and the blue light can be reduced. As a result, a display panel having high color gamut characteristics can be realized. That is, the performance of the display panel can be dramatically improved.

Moreover, since the quantum dot display panel has extremely high brightness and excellent visibility outdoors, it is suitable for a mobile phone, a display for in-vehicle use, a head-mounted display, or the like. In particular, these displays are expected to require a pixel resolution of 350 ppi (pixel per inch) or higher, and the use of quantum dot display panels is expected in the future.

Recently, a method for manufacturing a display panel using an inkjet method has attracted attention. For example, in an organic EL display panel, when each light emitting layer of a red light emitting layer, a blue light emitting layer, and a green light emitting layer or a hole injection layer is formed, an area (opening) in which ink containing an organic EL material is surrounded by a partition wall called a bank. Part) to dry the ink solvent. In this way, by forming the light emitting layer or the like by the inkjet method, the light emitting layer or the like is conventionally formed by the vacuum vapor deposition method, but it becomes possible to form the light emitting layer or the like in the atmosphere.

Moreover, the organic EL material constituting the light emitting layer is very expensive. For this reason, when the vacuum vapor deposition method is used, the organic EL material adheres to the wall surface of the chamber of the vapor deposition apparatus, so that a large amount of waste material is generated, the utilization efficiency of the material is lowered, and the display panel becomes expensive. On the other hand, when the inkjet method is used, the light emitting layer can be formed in the atmosphere, which saves energy, and the ink containing the organic EL material can be applied separately only to a predetermined place. , A low-cost display panel can be realized.

In recent years, as with the ink containing an organic EL material, the ink containing a quantum dot material has been actively studied by using an inkjet method. As a typical quantum dot material, an inorganic material such as cadmium-selenium or indium-phosphide is used as the core, and a material such as zinc sulfide is used as the shell around the core. In addition, a ligand may be formed around it to achieve stability as an ink.

For example, Patent Document 1 discloses a method of manufacturing a device used for an organic EL display panel or a quantum dot display panel by using an inkjet method. FIG. 13 shows a cross-sectional view of the device disclosed in Patent Document 1. As shown in FIG. 13, in the device disclosed in Patent Document 1, the ink to be applied is applied by applying the ink to the region (opening) surrounded by the partition wall 24X formed on the substrate 22X by the inkjet method. A functional film 21X corresponding to the function is formed. When the device disclosed in Patent Document 1 is used as a display panel, the area surrounded by the partition wall becomes a pixel, and the functional film 21X becomes a light emitting layer.

International Publication No. 2016/010077

However, when the device disclosed in Patent Document 1 is used for a display panel, the interval for arranging the region surrounded by the partition wall as a pixel in the plane of the substrate becomes narrow. Therefore, when the resolution of the pixels is increased, when the ink is ejected to the area surrounded by the partition wall, the landing of the ink is deviated, and the ink may be mixed into the unintended pixels to cause color mixing.

For example, when the resolution of the pixels of the target display panel is 400 ppi, the distance between the pixels and the width of the partition wall are approximately as follows in the device having the light emitting layer and the partition wall used for this display panel. 1A is a plan view showing an example of the configuration of a device used for a display panel having a pixel resolution of 400 ppi, and FIG. 1B is a cross-sectional view taken along the line IB-IB of FIG. 1A, which is shown in FIG. 1A. It shows how ink is ejected to the pixels of the device. Note that FIG. 1B shows a state before the light emitting layer 21Y is formed.

In the display panels shown in FIGS. 1A and 1B, a light emitting layer 21Y provided at a position corresponding to each pixel of red (R), green (G), and blue (B) and a partition wall surrounding each light emitting layer 21Y. It has 24Y, the distance between pixels of the same color is about 63 μm, and the distance between two adjacent pixels of different colors is 21 μm. The size of each pixel is 15 μm in diameter, and the width of the partition wall separating two adjacent pixels is 6 μm. Since the size of each pixel is designed from the light emission characteristics of the display panel and the like, it is not necessarily as described above, but a typical numerical value is as described above.

Further, FIG. 1B shows a state in which droplets of ink 40Y are ejected into a region (pixel) surrounded by the partition wall 24Y when the light emitting layer 21Y is formed by the inkjet method. For example, consider a case where the ink 40Y is applied to the region surrounded by the partition wall 24Y by an inkjet head capable of ejecting the ink 40Y having a droplet volume of 1 picolitre (pL). The diameter of the droplet of the ink 40 having a volume of 1 pL is 12.6 μm. On the other hand, the width of the region to which the ink 40Y should be applied is 15 μm as described above. Therefore, the size of the droplets of the ink 40Y is almost the same as the width of the region to which the ink 40Y is applied, and the landing position accuracy of the ink 40Y to be applied is required to be extremely high. For this reason, it is practically difficult to stably form a coating film without color mixing, and there is a risk that the yield at the time of manufacturing the device will decrease, the cost will increase, and the light emission characteristics will decrease due to color mixing.

The present disclosure has been made to solve such a problem, and even if the distance between the regions surrounded by the partition walls is narrow, a functional film such as a light emitting layer can be formed by using an inkjet method. An object of the present invention is to provide a color conversion device, a micro LED display panel, and the like that can achieve both suppression of deterioration of light emission characteristics and cost reduction.

In order to solve the above problems, one aspect of the color conversion device according to the present disclosure is to contact the substrate, the light emitting layer containing the light emitting material, and the light emitting layer, and the light emitting layer is formed. It has a first partition wall that defines a light emitting region that emits light, and a second partition wall that defines a formation region that comes into contact with the light emitting layer and forms the light emitting layer. The light emitting layer and the first The contact area with the partition wall is a color conversion device larger than the contact area between the light emitting layer and the second partition wall.

Further, one aspect of the micro LED display panel according to the present disclosure is a micro LED display panel having the color conversion device and a light emitting device that emits light incident on the color conversion device.

Further, one aspect of the method for manufacturing a color conversion device according to the present disclosure includes a first step of forming a first partition wall on a substrate that defines a light emitting region in which a light emitting layer emits light.
A second step of forming a second partition wall on the substrate, which defines a formation region in which the light emitting layer is formed,
The region surrounded by the second partition wall includes a third step of applying an ink containing a light emitting material to form the light emitting layer.
In the first step and the second step, the first distance from the substrate to the top of the first partition wall is shorter than the second distance from the substrate to the top of the second partition wall. A method for manufacturing a color conversion device that forms the first partition wall and the second partition wall.

Further, one aspect of the method for manufacturing a micro LED display panel according to the present disclosure is a method for manufacturing a micro LED display panel using the color conversion device manufactured by the above method for manufacturing a color conversion device, wherein the color conversion is performed. It is a method of manufacturing a micro LED display panel including a step of bonding a device and a light emitting device that emits light incident on the color conversion device.

According to the present disclosure, even if the distance between the regions surrounded by the partition walls is narrow, a functional film such as a light emitting layer can be formed by using an inkjet method, so that deterioration of light emitting characteristics can be suppressed and cost can be reduced. It is possible to achieve both.

Top view showing an example of the configuration of a device used for a display panel having a pixel resolution of 400 ppi. A cross-sectional view showing a state when ink is ejected to the pixels of the device shown in FIG. 1A. Cross-sectional view of the micro LED display panel according to the embodiment Top view of the color conversion device according to the embodiment FIG. 3A is a cross-sectional view of the color conversion device according to the embodiment taken along the line IIIB-IIIB. Sectional drawing which shows the other structure of the color conversion device which concerns on embodiment The figure for demonstrating the substrate preparation step in the manufacturing method of the color conversion device which concerns on embodiment. The figure for demonstrating the first partition wall forming step in the manufacturing method of the color conversion device which concerns on embodiment. The figure for demonstrating the 2nd partition wall forming step in the manufacturing method of the color conversion device which concerns on embodiment. The figure for demonstrating the light emitting layer formation step in the manufacturing method of the color conversion device which concerns on embodiment. The figure for demonstrating the partition wall material application step in the 1st bulkhead and the other manufacturing method of the 2nd bulkhead in the color conversion device which concerns on embodiment. The figure for demonstrating the exposure step in the 1st bulkhead and the other manufacturing method of the 2nd bulkhead in the color conversion device which concerns on embodiment. The figure for demonstrating the etching step in the 1st bulkhead and the other manufacturing method of the 2nd bulkhead in the color conversion device which concerns on embodiment. Top view showing another configuration of the color conversion device according to the embodiment. Sectional drawing of the color conversion device in the VIIB-VIIB line of FIG. 7A Top view of the color conversion device of the comparative example Sectional drawing of the color conversion device of the comparative example in line VIII-VIII of FIG. 8A Cross-sectional view of the color conversion device according to the first modification The figure which shows the state just before ink application in the ink application step of the manufacturing method of the color conversion device which concerns on modification 2. The figure which shows the state immediately after ink application in the ink application step of the manufacturing method of the color conversion device which concerns on modification 2. The figure which shows the state of the final state in the ink application step of the manufacturing method of the color conversion device which concerns on modification 2. Top view of the color conversion device according to the third modification Cross-sectional view of the color conversion device according to the third modification in the XIB-XIB line of FIG. 11A. A cross-sectional view of the color conversion device according to the third modification in the XIC-XIC line of FIG. 11A. Top view showing another configuration of the color conversion device according to the modification 3. Cross-sectional view of the device disclosed in Patent Document 1

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. It should be noted that all of the embodiments described below show a specific example of the present disclosure. Therefore, the numerical values, the components, the arrangement positions and connection forms of the components, the steps and the order of the steps, etc., which are shown in the following embodiments, are examples and do not limit the present disclosure. Therefore, among the components in the following embodiments, the components not described in the independent claims are described as arbitrary components.

Further, each figure is a schematic view and is not necessarily exactly illustrated. In each figure, substantially the same configuration is designated by the same reference numerals, and duplicate description will be omitted or simplified.

(Embodiment)
<Micro LED display panel>
First, the configuration of the micro LED display panel 1 according to the embodiment will be described with reference to FIG. FIG. 2 is a cross-sectional view of the micro LED display panel 1 according to the embodiment.

The micro LED display panel 1 is a display in which micro LEDs of micro order size are pixels. As shown in FIG. 2, the micro LED display panel 1 in the present embodiment has a light emitting device 10 and a color conversion device 20 arranged so as to face the light emitting device 10.

Although a specific manufacturing method will be described later, the micro LED display panel 1 can be manufactured by manufacturing the light emitting device 10 and the color conversion device 20 in separate steps and bonding them together.

By covering the bonded portion between the light emitting device 10 and the color conversion device 20 with a sealing material, it is possible to suppress the invasion of moisture and oxygen from the outside. As a result, deterioration of the micro LED display panel 1 can be suppressed, and a highly reliable micro LED display panel 1 can be realized.

The light emitting device 10 emits light incident on the color conversion device 20. In the present embodiment, the light emitting device 10 is a blue light emitting device that emits blue light. The light emitting device 10 is, for example, an LED device composed of LEDs, but may be an organic EL device composed of an organic EL or the like. It may be an inorganic EL that emits light from an inorganic material.

As shown in FIG. 2, the light emitting device 10 has a light emitting body 11. In the present embodiment, the light emitting device 10 has a substrate 12, and the light emitting body 11 is arranged on the substrate 12.
<Luminator 11>
Specifically, a plurality of light emitters 11 are arranged on the substrate 12. The light emitting body 11 is provided for each pixel of the micro LED display panel 1. That is, one light emitting body 11 is provided corresponding to one pixel in the micro LED display panel 1.

The light emitter 11 is a light source that emits light. In the present embodiment, the light emitting body 11 is a blue light emitting body that emits blue light. In this case, from the viewpoint of cost and the like, it is desirable to use the blue LED as the light emitting body 11, but the present invention is not limited to this. For example, when an organic EL device is used as the light emitting device 10, the light emitting body 11 is an organic EL light emitting body composed of an organic EL film.
<Board 12>
Any substrate 12 can be used as long as it has an insulating property. Examples of the substrate 12 include a resin substrate using an insulating resin material as a base material, a metal base substrate such as an aluminum alloy substrate having an insulating coating on the surface, a ceramic substrate made of a ceramic material, a glass substrate made of a glass material, and the like. Can be used. As the substrate 12, a translucent substrate having translucency may be used or a translucent substrate that does not transmit light may be used depending on the light extraction direction. When a translucent substrate is used as the substrate 12, the substrate 12 is a transparent substrate such as a transparent resin substrate or a glass substrate. Further, the substrate 12 may be a rigid substrate or a flexible substrate. A white insulating film such as a white resist may be formed on the surface of the substrate 12 in order to improve the withstand voltage and the light extraction efficiency.
<Light emitting device 10>
In the present embodiment, the light emitting device 10 has a partition wall 13. The partition wall 13 is provided so as to surround each light emitting body 11. By providing the partition wall 13, the light emitted from the light emitting body 11 can be prevented from leaking to the adjacent pixel. The partition wall 13 is made of, for example, a black or white resin material.

The light emitting device 10 may have a driving transistor for controlling the light emission of the light emitting body 11. Further, as for the blue LED used as the light emitting body 11, the blue LED manufactured in another step may be mounted on the substrate 12, or the blue LED may be directly formed on the substrate 12. For example, when an organic EL device is used as the light emitting device 10, an organic EL film as the light emitting body 11 may be directly formed on the substrate 12 by a vacuum deposition method or an inkjet method.
<Color conversion device 20>
Next, the color conversion device 20 will be described with reference to FIGS. 3A and 3B with reference to FIG. FIG. 3A is a plan view of the color conversion device 20 according to the embodiment, and FIG. 3B is a cross-sectional view of the same color conversion device 20 on the line IIIB-IIIB of FIG. 3A.

The color conversion device 20 has a function of converting the light incident on the color conversion device 20 into a wavelength of a predetermined color. Specifically, the color conversion device 20 uses a plurality of light emitting layers 21 as wavelength conversion layers that convert the wavelength of the light emitted from the light emitting device 10 into a wavelength of a color different from the color of the light emitted by the light emitting device 10. Have.

In the present embodiment, the color conversion device 20 has, as a plurality of light emitting layers 21, a red light emitting layer 21r having a function of converting the wavelength of blue light emitted from the light emitting device 10 into a red wavelength, and emitting from the light emitting device 10. It has a green light emitting layer 21g having a function of converting the wavelength of the blue light to a green wavelength, and a blue light emitting layer 21b having a function of transmitting the blue light emitted from the light emitting device 10 as it is.
<Light emitting layer 21>
The plurality of light emitting layers 21 are provided corresponding to the plurality of light emitting bodies 11 of the light emitting device 10. Specifically, each of the plurality of light emitting layers 21 is arranged so as to face each of the plurality of light emitting bodies 11. More specifically, each of the red light emitting layer 21r, the green light emitting layer 21g, and the blue light emitting layer 21b and the plurality of light emitting bodies 11 are provided in a one-to-one relationship so as to face each other. Therefore, each of the plurality of light emitting layers 21 is provided corresponding to one pixel in the micro LED display panel 1.

Here, the red light emitting layer 21r corresponding to the red pixel and the green light emitting layer 21 g corresponding to the green pixel contain a quantum dot material (light emitting material). As the quantum dot material, for example, a cadmium-selenium-based or indium-phosphorus-based, copper-indium-sulfur-based, silver-indium-sulfur-based, or perovskite-structured material can be used. In the present embodiment, the red light emitting layer 21r and the green light emitting layer 21g are composed of, for example, a resin film in which a quantum dot material is dispersed. In the red light emitting layer 21r and the green light emitting layer 21g, the concentration of the quantum dot material is preferably 5% by weight or more and 50% by weight or less.

The red light emitting layer 21r contains a quantum dot material that emits red light. In the present embodiment, the quantum dot material contained in the red light emitting layer 21r is excited by light having a blue wavelength emitted from the light emitting device 10 to emit red light. Therefore, when the red light emitting layer 21r is irradiated with light having a blue wavelength, the light having a blue wavelength is converted into a red wavelength and the red light is emitted from the red light emitting layer 21r.

The green light emitting layer 21 g contains a quantum dot material that emits green light. In the present embodiment, the quantum dot material contained in the green light emitting layer 21 g is excited by light having a blue wavelength emitted from the light emitting device 10 to emit green light. Therefore, when the green light emitting layer 21 g is irradiated with the light of the blue wavelength, the light of the blue wavelength is converted into the green wavelength and the green light is emitted from the green light emitting layer 21 g.

On the other hand, the blue light emitting layer 21b in the present embodiment is formed of a resin film that does not contain a quantum dot material. Therefore, when the blue light emitting layer 21b is irradiated with light having a blue wavelength, the blue light is emitted as it is from the blue light emitting layer 21b.

The resin material constituting the red light emitting layer 21r, the green light emitting layer 21g, and the blue light emitting layer 21b is, for example, an acrylic or epoxy resin. Further, as the resin material constituting the red light emitting layer 21r, the green light emitting layer 21g and the blue light emitting layer 21b, it is desirable to use an ultraviolet curable resin that is cured by irradiation with ultraviolet rays.

In the light emitting layer 21, diffusion particles (scattered particles) having a property of scattering light may be further present in the resin film. That is, the diffusion particles may be dispersed in the resin material constituting the red light emitting layer 21r, the green light emitting layer 21g, and the blue light emitting layer 21b. In this case, the blue light emitting layer 21b in the present embodiment contains only the diffusing particles among the quantum dot material and the diffusing particles.

As the diffusion particles, for example, titanium oxide particles, zirconia particles, hollow silica particles in which the inside of the particles is hollow, or the like can be used. The particle size of the diffused particles is, for example, 50 nm or more and 1000 nm or less. In each light emitting layer 21, the diffuse particles are contained, for example, in a concentration of several weight percent. Since the light emitting layer 21 contains diffused particles, the blue light traveling through the light emitting layer 21 is scattered and the optical path length is lengthened. As described above, by increasing the optical path length of the blue light traveling through the light emitting layer 21, the number of times the blue light hits the quantum dot material having the wavelength conversion function increases, and the wavelength conversion efficiency increases.

The light emitting layer 21 may further contain particles that absorb moisture. As a result, it is possible to prevent the light emitting layer 21 from being deteriorated by moisture.

The color conversion device 20 further has a substrate 22, and the light emitting layer 21 is located on the substrate 22. Specifically, the light emitting layer 21 is provided on the front surface, which is one surface of the substrate 22.
<Board 22>
As the substrate 22, any substrate 22 can be used as long as it has an insulating property. As the substrate 22, for example, a resin substrate, a metal base substrate, a ceramic substrate, a glass substrate, or the like can be used. As the substrate 22, a translucent substrate having translucency may be used, or a translucent substrate that does not transmit light may be used, depending on the light extraction direction. When a translucent substrate is used as the substrate 22, the substrate 22 is a transparent substrate such as a transparent resin substrate or a glass substrate. Further, the substrate 22 may be a rigid substrate or a flexible substrate.

In this embodiment, a glass substrate is used as the substrate 22. In this case, a light-shielding film having a light-shielding property may be formed on the substrate 22 so that the light emitted from the light-emitting layer 21 does not pass through the substrate 22. For example, as the light-shielding film, a light-reflecting film having light reflectivity may be formed on the front surface (the surface provided with the light emitting layer 21) of the substrate 22. The light-reflecting film is, for example, a white film such as a white resist made of a white insulating resin material or the like. Alternatively, as the light-reflecting film, a metal film having light-reflecting property may be formed on the back surface of the substrate 22. Specifically, a metal film made of a silver-palladium-copper alloy or the like may be formed on the back surface of the substrate 22.

Further, the color conversion device 20 has a first partition wall 23 and a second partition wall 24. The first partition wall 23 and the second partition wall 24 are provided on the front surface, which is one surface of the substrate 22, like the light emitting layer 21.
<Septum>
The first partition 23 and the second partition 24 surround the light emitting layer 21. The first partition wall 23 defines a light emitting region in which the light emitting layer 21 emits light. On the other hand, the second partition wall 24 defines a forming region where the light emitting layer 21 is formed. In the present embodiment, since the light emitting layer 21 is formed by applying ink, the second partition wall 24 becomes a coating region (ink coating region) to which the ink is applied.

In the present embodiment, the second partition wall 24 is integrally formed in common with the plurality of light emitting layers 21. The second partition wall 24 is formed with a plurality of openings corresponding to each of the plurality of light emitting layers 21 as a region surrounded by the second partition wall 24. That is, the light emitting layer 21 is formed in the plurality of openings formed by the second partition wall 24. The first partition wall 23 is provided in each of the plurality of openings of the second partition wall 24. That is, a plurality of first partition walls 23 are provided corresponding to each of the plurality of light emitting layers 21. The shape of the opening formed (enclosed) by the second partition wall 24 is an elliptical shape or a shape obtained by adding two crescent shapes that oppose the circular shape. With such a shape, openings can be formed at high density, the distance between the openings can be maintained, and color mixing does not occur. Further, the region formed by the first partition wall 23 has a circular shape. This is because the light emission is homogeneous.

The first partition wall 23 is formed in the shape of a crescent pillar (columnar body) in two opposite directions on the side surface of the opening formed by the second partition wall 24. The volume of the opening can be secured, the space in which the light emitting layer 21 is mainly formed can be formed into a cylindrical shape, and the amount of light emitted can be secured.

In each pixel, the region (opening) surrounded by the second partition wall 24 has a flat shape in a plan view. In the present embodiment, the region (opening) surrounded by the second partition wall 24 has a race track-like oval shape in a plan view. Further, the region surrounded by the first partition wall 23 located inside the second partition wall 24 has a circular shape in a plan view.

Further, in each pixel, the first partition wall 23 is formed so as to contact the inner wall surface of the second partition wall 24. In the present embodiment, the region surrounded by the second partition wall 24 includes one region surrounded by the first partition wall 23. That is, one light emitting layer 21 is provided in the region surrounded by the second partition wall 24.

The film thickness of the first partition wall 23 is thinner than the film thickness of the second partition wall 24. That is, the height of the first partition wall 23 is lower than the height of the second partition wall 24. Specifically, the first distance from the substrate 22 to the top of the first partition wall 23 is shorter than the second distance from the substrate 22 to the top of the second partition wall 24. As an example, the first distance (film thickness) of the first partition wall 23 is approximately 2 μm or more and 9 μm or less, and preferably 3 μm or more and 7 μm or less. On the other hand, the second distance (film thickness) of the second partition wall 24 is approximately 5 μm or more and 10 μm or less, and preferably 6 μm or more and 8 μm or less.

Each light emitting layer 21 is in contact with each of the first partition 23 and the second partition 24. Specifically, in each of the red light emitting layer 21r, the green light emitting layer 21g, and the blue light emitting layer 21b, the light emitting layer 21 is in contact with each of the first partition wall 23 and the second partition wall 24. As a result, the partition wall surrounding the light emitting layer 21 and the light emitting layer 21 (first partition wall 23 and the second partition wall 23) is compared with the case where the light emitting layer 21 is in contact with only one of the first partition wall 23 and the second partition wall 24. Since the contact area with the partition wall 24) can be increased, the adhesion of the light emitting layer 21 is improved. Therefore, the reliability of the color conversion device 20 is improved, particularly when the substrate 22 is a flexible substrate.

The first partition wall 23 is formed so as to surround the red light emitting layer 21r, the green light emitting layer 21g, and the blue light emitting layer 21b at each opening of the second partition wall 24. In the region (opening) surrounded by the second partition wall 24, the light emitting layer 21 is in contact with the entire inner wall surface of the first partition wall 23 and is in contact with the upper portion of the inner wall surface of the second partition wall 24. doing.

Further, since the film thickness of the first partition wall 23 is thinner than the film thickness of the second partition wall 24, the film thickness of the light emitting layer 21 located at the top of the first partition wall 23 is larger than that of the other portions. It's getting thinner. Therefore, the light emitting layer 21 located at the top of the first partition wall 23 has almost no wavelength conversion function and does not emit light. Further, even if the light is slightly emitted, the light is blocked by the first partition wall 23, so that the light is not taken out to the outside of the light emitting layer 21. Therefore, only the region defined inside the first partition wall 23 contributes to light emission. With such a structure, it is possible to specify a light emitting region in which the light emitting layer 21 emits light with a predetermined size while securing a wide forming region (ink coating region) in which the light emitting layer 21 is formed. The light emitting layer 21 to be a film can be formed with high quality and low cost.

Each of the first partition wall 23 and the second partition wall 24 may be made of either an inorganic material or an organic material as long as it has an insulating property. As an example, the first partition 23 and the second partition 24 are preferably formed using a photosensitive resin that is cured by ultraviolet rays. It is preferably formed of the same resin material.

Further, it is desirable that the first partition wall 23 that defines the light emitting region in which the light emitting layer 21 emits light is white so that the light emitted by each light emitting layer 21 can be efficiently taken out. For example, a white resist or the like can be used as the first partition wall 23. On the other hand, it is desirable that the second partition wall 24, which defines the formation region where the light emitting layer 21 is formed, has a lower wettability than the first partition wall 23 and exhibits liquid repellency to the ink to be applied. Therefore, for example, as the second partition wall 24, it is preferable to use a fluororesin or the like in which a functional group containing a fluorine atom is contained in the resin in order to impart liquid repellency. The fluororesin is not particularly limited as long as it has a fluorine atom in at least a part of the polymer repeating units. Examples of the fluororesin used as the material of the second partition wall 24 include a fluorinated polyolefin resin, a fluorinated polyimide resin, and a fluorinated polyacrylic resin.

Further, as described above, in the present embodiment, the second partition wall 24 has a lower wettability than the first partition wall 23. That is, the first partition wall 23 is made of a material having a higher wettability than the second partition wall 24. Therefore, in each light emitting layer 21, the contact area between the light emitting layer 21 and the first partition wall 23 may be larger than the contact area between the light emitting layer 21 and the second partition wall 24. As a result, the adhesion of the light emitting layer 21 can be improved.
<Color filter 25>
As shown in FIG. 4, the color conversion device may be provided with the color filter 25. For example, the red light emitting layer 21r is provided with the red color filter 25r, the green light emitting layer 21g is provided with the green color filter 25g, and the blue light emitting layer 21b is provided with the blue color filter 25b. By providing the color filter 25 in this way, it is possible to transmit only a desired wavelength, so that color reproducibility can be improved. Specifically, the chromaticity of the light emitted by the red light emitting layer 21r, the green light emitting layer 21g, and the blue light emitting layer 21b is increased with respect to the blue light emitted by the light emitting device 10 that emits blue light, so that the color reproducibility is improved. Increase. Further, by providing the color filter 25, the luminous efficiency of the light emitting layer 21 can be improved.

<Manufacturing method of micro LED display panel>
Next, a method of manufacturing the micro LED display panel 1 according to the embodiment will be described.

The method for manufacturing the micro LED display panel 1 according to the present embodiment includes a step of manufacturing the light emitting device 10, a step of manufacturing the color conversion device 20, and a step of bonding the color conversion device 20 and the light emitting device 10. Including.

[Manufacturing method of light emitting device]
First, a method of manufacturing the light emitting device 10 will be described. For example, the light emitting device 10 can obtain the light emitting device 10 in which the light emitting body 11 is arranged on the substrate 12 by transferring the light emitting body 11 that emits blue light produced in another step onto the substrate 12. .. In this case, it is preferable to provide the partition wall 13 on the substrate 12 so that the light emitted from the light emitting body 11 does not leak to the adjacent pixel. The partition wall 13 is provided so as to surround the light emitting body 11.

[Manufacturing method of color conversion device]
Next, a method of manufacturing the color conversion device 20 will be described with reference to FIGS. 5A to 5D. 5A to 5D are diagrams for explaining a manufacturing flow in the manufacturing method of the color conversion device 20 according to the embodiment. 5A, 5B, 5C and 5D show a substrate preparation step, a first partition wall forming step, a second partition wall forming step and a light emitting layer forming step, respectively.

The method for manufacturing the color conversion device 20 includes a step of preparing the substrate 22 (board preparation step) as shown in FIG. 5A and a light emitting region on which the light emitting layer 21 emits light as shown in FIG. 5B. The step of forming the first partition wall 23 to be defined (first partition wall formation step) and the second partition wall 24 to define the formation region where the light emitting layer 21 is formed on the substrate 22 as shown in FIG. 5C. (Second partition wall forming step) and, as shown in FIG. 5D, a step of applying an ink containing a quantum dot material to a region surrounded by the second partition wall 24 to form a light emitting layer 21. (Light emitting layer forming step) and.

Then, in the first partition wall forming step and the second partition wall forming step, the first distance from the substrate 22 to the top of the first partition wall 23 is the second distance from the substrate 22 to the top of the second partition wall 24. The first partition wall 23 and the second partition wall 24 are formed so as to be shorter.

Hereinafter, specific examples of each step of the first partition wall forming step, the second partition wall forming step, and the light emitting layer forming step will be described.

(Board preparation step)
In the board preparation step, the board 22 is prepared as shown in FIG. 5A. In the present embodiment, a glass substrate is prepared as the substrate 22.

(First partition wall forming step)
In the first partition wall forming step, the first partition wall 23 is formed on the substrate 22. The first partition wall 23 can be formed, for example, by a photolithography process using a photosensitive resin.

Specifically, a coating film is formed on the substrate 22 by applying a photosensitive resin that is cured by exposure to ultraviolet light onto the substrate 22 using a coating method such as spin coating or slit coating. At this time, the coating conditions of the photosensitive resin may be adjusted by adjusting the rotation speed of the spin coating, the scanning speed of the slit coating, or the like according to the required film thickness. Next, the coating film is prebaked using a hot plate or the like to dry the solvent component, and then the ultraviolet light is exposed through a photomask in which a desired pattern is formed. The photosensitive resin includes a negative type material in which the exposed portion irradiated with ultraviolet light is cured and a positive type material in which the unexposed portion of ultraviolet light is cured, and either material may be used. Next, the uncured portion is removed using an appropriate developer depending on the type of the photosensitive resin material, and then the remaining pattern is post-baked in a curing furnace or the like. As a result, as shown in FIG. 5B, the first partition wall 23 having a predetermined shape can be formed on the substrate 22.

In the present embodiment, a white resin having high reflectance was used as the material of the first partition wall 23. As the white resin, an acrylic resin or an epoxy resin to which an inorganic substance such as white titanium oxide particles is added can be used. Then, a white resin was applied to the substrate 22 by a slit coat, and prebaked by heating on a hot plate at 80 ° C. for 30 minutes. Then, the white resin was cured by irradiating with ultraviolet light having a wavelength of 365 nm. The exposure amount of ultraviolet rays was set to 500 mJ / cm ² . Then, the white resin was developed with a developing solution. Specifically, a white resin was developed by spray coating for 60 seconds using 1 wt% Na ₂ CO ₃ as a developing solution. Then, the white resin was post-baked at 150 ° C. for 60 minutes using a curing furnace. As a result, the first partition wall 23 made of white resin having a film thickness of 5 μm was formed.

In the present embodiment, the first partition wall 23 is made of white resin, but may be made of yellow resin in order to improve weather resistance. Further, in order to increase the contrast of the emitted color, a resin having a two-layer structure in which the lower part of the first partition wall 23 is black and the upper part is white may be used.

(Second partition wall formation step)
In the second partition wall forming step, the second partition wall 24 is formed on the outside of the first partition wall 23. Specifically, similarly to the first partition wall 23, the second partition wall 24 can be formed on the outside of the first partition wall 23 by a photolithography process using a photosensitive resin, as shown in FIG. 5C. it can. At this time, the second partition wall 24 is formed so that the film thickness of the second partition wall 24 is thicker than the film thickness of the first partition wall 23. Further, as described above, the region surrounded by the second partition wall 24 has a flat shape in a plan view.

In the present embodiment, a fluorine-containing acrylic resin containing fluorine was used as the material of the second partition wall 24. Specifically, as the fluorine-containing acrylic resin, a material having a characteristic that fluorine is unevenly distributed on the surface by exposure was used. Therefore, the surface of the second partition wall 24 has liquid repellency.
Here, the contact angle will be described. When a liquid is dropped on a solid surface, the liquid is rounded by its own surface tension, and a relationship like Equation 1 called Young's equation is established.

γ _s = γ _L × cos θ + γ _SL ... (Equation 1)
γ _s : Surface tension of solid γ _L : Surface tension of liquid γ _SL : Interfacial tension of solid and liquid The angle θ between the tangent of the droplet and the surface of the solid at this time is called the contact angle. Above all, the contact angle when the liquid is stationary on a solid and reaches an equilibrium state is called a static contact angle. On the other hand, the contact angle in a dynamic state where the interface between the liquid and the solid is moving, that is, the interface of the droplet is moving is called a forward contact angle and a backward contact angle.
Specifically, the static contact angle of the second partition wall 24 with respect to the ink was about 50 °. Further, since the film thickness of the first partition wall 23 was set to 5 μm as described above, the second partition wall 24 was formed to have a film thickness of 8 μm in order to make it thicker than the first partition wall 23. ..

In the present embodiment, the second partition wall forming step is performed after the first partition wall forming step, but the first partition wall forming step and the second partition wall forming step are exchanged to form the second partition wall. The steps may be taken first. That is, the first partition wall forming step may be performed after the second partition wall forming step.

Further, in the present embodiment, the first partition wall 23 and the second partition wall 24 are manufactured in separate steps, but by halftone exposure using the same material and having different transmittances depending on the location, in one step. The first partition wall 23 and the second partition wall 24 may be manufactured at the same time. The method is shown in FIGS. 6A to 6C.

Specifically, first, as shown in FIG. 6A, the partition wall material 30 is formed on the substrate 22 by a spin coating method or a slit coating method. As the partition wall material 30, for example, the same material as the first partition wall 23 or the second partition wall 24 can be used.

Next, as shown in FIG. 6B, the partition material 30 is exposed to light and cured by irradiating ultraviolet light through the photomask 100. Here, the degree of curing of the partition wall material 30 is changed by locally changing the transmittance of ultraviolet light. For example, the photomask 100 has a shielding portion 101 that shields ultraviolet light, and a first opening 102 and a second opening 103 having different transmittances. The transmittance of the second opening 103 is higher than that of the first opening 102.

Next, as shown in FIG. 6C, the uncured portion of the partition wall material 30 is etched with a developer. At this time, since the degree of curing is small in the portion where the amount of ultraviolet light transmitted is small, the film thickness after etching is reduced.

In this way, the first partition wall 23 and the second partition wall 24 having different film thicknesses can be simultaneously produced by etching by halftone exposure. The above method uses a negative type material in which the portion irradiated with ultraviolet light is cured, but a positive type material in which the portion irradiated with ultraviolet light is dissolved may also be used. In this case, the relationship of the transmittance of the photomask 100 is different, the shielding portion 101 is used as the first opening, the second opening 103 is used as the shielding portion, and the first opening is more transparent than the second opening. The rate should be increased.

(Light emitting layer formation step)
In the light emitting layer forming step, first, a coating film is formed by applying ink to the substrate 22 on which the first partition wall 23 and the second partition wall 24 are formed by using an inkjet method. In the present embodiment, with respect to the red light emitting layer 21r and the green light emitting layer 21g, ink in which the quantum dot material is dispersed at a predetermined concentration is ejected to a region surrounded by the second partition wall 24 by an inkjet method. Further, with respect to the blue light emitting layer 21b, ink containing no quantum dot material is ejected to a region surrounded by the second partition wall 24 by an inkjet method. When forming the coating film constituting the red light emitting layer 21r, the green light emitting layer 21g and the blue light emitting layer 21b, the ejection amount is adjusted so that the film thickness after the ejected ink is dried and cured becomes a predetermined film thickness. decide.

In the present embodiment, the ink used is a cadmium-selenium-based quantum dot material dispersed in an acrylic resin. As the quantum dot material, a material having a particle size of 20 nm or more and 30 nm or less was used. Further, the ink contains titanium oxide particles in order to scatter blue light and increase the optical path length in the light emitting layer 21. As the titanium oxide particles, those having a particle size of approximately 100 nm or more and 1000 nm or less were used. This ink was applied to the area surrounded by the second partition wall 24 by an inkjet method.

Further, in the present embodiment, the ink application direction is a direction perpendicular to the long axis direction of the region surrounded by the second partition wall 24. That is, the printing direction of the ink is a direction perpendicular to the long axis direction of each of the R, G, and B pixels. Further, nozzles of the inkjet head for applying ink are provided for each of the red light emitting layer 21r, the blue light emitting layer 21b, and the green light emitting layer 21g, and the arrangement direction of these nozzles is the region surrounded by the second partition wall 24. It is the same as the long axis direction of. As a result, ink can be easily applied without mixing colors even in a high-resolution pixel arrangement pattern in which the distance between the regions surrounded by the second partition wall 24 is narrow. This point will be described below.

Regarding the ink application direction (printing direction), the ink can be landed at a predetermined position relatively easily by adjusting the ink ejection timing. On the other hand, regarding the arrangement direction of the nozzles, it is difficult to correct the landing position of the ink, and it depends on the processing accuracy of the nozzles. Therefore, in the present embodiment, by making the arrangement direction of the nozzles the same as the long axis direction of the region surrounded by the second partition wall 24, the area where the ink can land is expanded in the arrangement direction of the nozzles. Therefore, the swing width of the permissible ink landing position is increased. Specifically, the area surrounded by the second partition wall 24, which is the coating area to which the ink is applied, is widened with respect to the region surrounded by the first partition wall 23 (that is, the light emitting region where the light emitting layer 21 emits light). There is. As a result, ink can be easily applied without mixing colors even in a high-resolution pixel arrangement pattern.

Next, the substrate 22 on which the coating film is formed by applying the ink is dried. In this case, as the ink ejected by the inkjet method, a solvent having a high boiling point is often used in order to suppress solvent drying at the nozzle. Therefore, it is preferable to use vacuum drying as the ink drying. When performing vacuum drying, for example, the substrate 22 coated with ink is set in a drying furnace, and the inside of the drying furnace is depressurized by a vacuum pump to reduce the pressure to promote the evaporation of the solvent. In this case, the ultimate vacuum is several Pa and the holding time is several tens of minutes. However, the conditions of the ultimate vacuum degree and the holding time are not limited to these conditions because they differ depending on the boiling point of the solvent contained in the ink. When the ejected ink does not contain a solvent and the quantum dot material is dispersed only in the ultraviolet photocurable resin, drying such as vacuum drying may not be performed.

Next, the coating film is prebaked on a hot plate at 100 ° C. for about 5 minutes. Next, the coating film is cured by irradiating the coating film with ultraviolet light having a wavelength of 365 nm. In this case, the irradiation amount of ultraviolet light is, for example, 200 mJ / cm ² or more and 1000 mJ / cm ² or less. Next, the coating film is post-baked at 150 ° C. for 20 minutes using a curing furnace. As a result, as shown in FIG. 5D, the light emitting layer 21 can be formed in each of the regions (openings) surrounded by the second partition wall 24.

In the present embodiment, a coating film coated on the substrate 22 by prebaking (100 ° C. for 5 minutes), irradiating with ultraviolet light (wavelength 365 nm, exposure amount 300 mJ / cm ² ), and post-baking (150 ° C. for 20 minutes). Was cured.

As described above, as shown in FIGS. 3A and 3B, the color conversion device 20 in which a plurality of light emitting layers 21 are arranged at a predetermined pitch can be manufactured.

In the present embodiment, as shown in FIGS. 3A and 3B, the arrangement direction of the light emitting layers 21 of the same color coincides with the direction perpendicular to the long axis direction of the region surrounded by the second partition wall 24. It was configured in, but it is not limited to this. For example, as shown in FIGS. 7A and 7B, the arrangement direction of the light emitting layers 21 of the same color is configured to intersect (inclinate) the direction perpendicular to the long axis direction of the region surrounded by the second partition wall 24. It may have been done. The inclination angle is preferably 30 to 60 degrees and 40 to 50 degrees with respect to the edge of the substrate 12. FIG. 7A is a plan view showing another configuration of the color conversion device according to the embodiment, and FIG. 7B is a cross-sectional view of the color conversion device along the VIIB-VIIB line of FIG. 7A. By adopting the configuration shown in FIGS. 7A and 7B, the distance between the regions surrounded by the second partition wall 24 can be narrowed and the number of light emitting layers 21 can be easily increased. That is, a color conversion device having a higher resolution can be easily realized.

(Action effect, etc.)
Next, the effects of the color conversion device 20 according to the present embodiment will be described in comparison with the color conversion device 20Z of the comparative example. FIG. 8A is a plan view of the color conversion device 20Z of the comparative example, and FIG. 8B is a cross-sectional view of the color conversion device 20Z of the comparative example in the line VIII-VIII of FIG. 8A.

As shown in FIGS. 8A and 8B, in the color conversion device 20Z of the comparative example, the first partition wall 23 and the ink coating area that define the light emitting region are defined for the color conversion device 20 according to the present embodiment. Of the second partition 24, the first partition 23 does not exist. That is, in the color conversion device 20Z of the comparative example, only the second partition wall 24 is present among the first partition wall 23 and the second partition wall 24.

In the color conversion device 20Z of the comparative example configured as described above, the light emitting region of the light emitting layer 21 is larger than that of the color conversion device 20 according to the present embodiment shown in FIGS. 3A and 7A. That is, the pixel size increases. If the distance between the pixels is too short, mutual interference between the emitted colors may occur, so it is conceivable that the design must be designed with the distance between the pixels separated. In such a case, in the display using the color conversion device 20Z of the comparative example, the resolution becomes low and it becomes difficult to realize high-definition image quality.

On the other hand, in the color conversion device 20 of the present embodiment, a second partition wall 24 that defines an ink application region and a first partition wall 23 that defines a light emitting region are formed. Specifically, the first partition wall 23 is formed inside the region surrounded by the second partition wall 24.

With this configuration, the color conversion device 20 in the present embodiment can reduce the light emitting region emitted by the light emitting layer 21 even when the ink coating area is the same as that of the color conversion device 20Z of the comparative example. .. As a result, the pixel size can be substantially reduced and the resolution can be increased with respect to the color conversion device 20Z of the comparative example. In other words, even in the color conversion device 20 having pixels arranged at high resolution, the light emitting layer 21 can be easily formed by the inkjet method.

Therefore, according to the color conversion device 20 and the micro LED display panel 1 in the present embodiment, even if the distance between the regions (openings) surrounded by the second partition wall 24 is narrow, the light emitting layer is used by the inkjet method. 21 can be formed. As a result, the ink can be stably applied without mixing colors, so that it is possible to achieve both suppression of deterioration of light emission characteristics and cost reduction.

(Modification example 1)
Next, the color conversion device 20A according to the first modification will be described with reference to FIG. FIG. 9 is a cross-sectional view of the color conversion device 20A according to the first modification.

As shown in FIG. 9, the color conversion device 20A according to the present modification further has a light emitting body 26 on the substrate 22 with respect to the color conversion device 20 according to the above embodiment. Specifically, the light emitting body 26 is a blue light emitting body that emits blue light such as a blue LED. The light emitting body 26, which is a blue LED, can be formed by mounting it on the substrate 22. The other configurations are the same as those of the color conversion device 20 in the above embodiment.

As described above, according to the color conversion device 20A according to the present modification, since the light emitting body 26 is incorporated, the color conversion device 20A can be provided with the function of the light emitting device. As a result, the micro LED display panel can be realized without attaching the light emitting device 10 to the color conversion device 20A. That is, the color conversion device 20A itself can be used as a micro LED display. Therefore, the thickness of the micro LED display panel can be reduced.

(Modification 2)
Next, the color conversion device 20B according to the second modification will be described with reference to FIGS. 10A to 10C. 10A to 10C are diagrams for explaining a method of manufacturing the color conversion device 20B according to the second modification.

The color conversion device 20B according to this modification has a lower wettability at the top of the first partition wall 23B than the color conversion device 20 according to the above embodiment. Specifically, in each light emitting layer 21, the static contact angle of the top of the first partition 23B with respect to the ink 40 is equal to or greater than the static contact angle of the inner wall surface (side surface) of the first partition 23 with respect to the ink 40. It has become. Regarding the second partition wall 24B, in each light emitting layer 21, the static contact angle of the top of the second partition wall 24B with respect to the ink 40 is the static contact angle of the inner wall surface (side surface) of the second partition wall 24B with respect to the ink 40. Is bigger than. In addition, in FIGS. 10A and 10B, the ink 40r indicates the ink for forming the red light emitting layer 21r, and the ink 40g indicates the ink for forming the green light emitting layer 21g.

In this modification, the static contact angle of the top of the first partition 23B with respect to the ink 40 is C1, the static contact angle of the inner wall surface of the first partition 23B is C2, and the static contact angle of the top of the second partition 24B is C2. Is C3, and the static contact angle of the inner wall surface of the second partition wall 24B is C4. C1 to C4 satisfy the relational expression of C3> C1 ≧ C2 = C4. As an example, the static contact angles C1 and C3 are 40 ° or more and 70 ° or less, and the static contact angles C2 and C4 are 5 ° or more and 40 ° or less.

As the first partition wall 23B and the second partition wall 24B, a resin material can be used in which the portion irradiated with ultraviolet light is cured and the fluorine component in the resin is segregated on the surface of the film. Thereby, the first partition wall 23B and the second partition wall 24B whose top static contact angle is larger than the static contact angle of the inner wall surface can be formed. The configuration other than the first partition wall 23B and the second partition wall 24B is the same as the color conversion device 20 in the above embodiment.

Initially, the material for forming the partition wall contains fluorine uniformly in the liquid state. Apply and expose to form partition walls. The polymerization reaction starts at the exposed portion. After that, it is completely cured by baking. At that time, the fluorine component in the film segregates upward. As a result, the formed partition wall contains a large amount of fluorine on the surface.

The static contact angle between the top of the first partition wall 23B and the top of the second partition wall 24B can be adjusted by using the above-mentioned material such that the static contact angle changes depending on the film thickness of the partition wall. The fluorine-containing resin used has a different fluorine content depending on the film thickness, and the static contact angle changes. Further, the static contact angle may be changed by using different materials for the first partition wall and the second partition wall.

As described above, in the color conversion device 20B in the present modification, the wettability of the top of the first partition wall 23B is low, so that the area surrounded by the second partition wall 24B is ink-inked as shown in FIG. 10A. When the ink 40 is applied by the method, immediately after the ink 40 is applied, the ink 40 is present so as to cover the top of the first partition wall 23B as shown in FIG. 10B, but the first partition wall 23B Since the static contact angle of the top of the ink 40 with respect to the ink 40 is larger than the static contact angle of the inner wall surface of the first partition 23B with respect to the ink 40, the ink 40 on the top of the first partition 23B is the first. The ink 40 slides down along the inner wall surface of the partition wall 23B, and finally the ink 40 is contained in the area surrounded by the first partition wall 23B.

The wettability of the top of the second partition wall 24B is defined by the receding contact angle in addition to the above-mentioned static contact angle. The receding contact angle is the contact angle in a dynamic state where the interface between the liquid and the solid is moving, that is, the interface between the inks is moving. If the receding contact angle is small, the ink that has run on the partition wall tends to remain wet and remains on the partition wall when it dries or hardens and shrinks. The receding contact angle of the second partition wall 24B with respect to the ink is 15 ° or more, more preferably 20 ° or more.
(Comparison of ink wetting due to difference in receding contact angle)
Table 1 shows the static contact angle and the receding contact angle of the ink when the type of the partition wall is changed, and the wetting of the ink on the partition wall.

後退接触角はインクの材料組成と隔壁の材料組成の表面エネルギーのバランスで決まる。インクＡやインクＢのように後退接触角が１５°以上であると、インク収縮後に隔壁上にインクの濡れ残りがないが、インクＣやインクＤのように後退接触角が１５°以下であると、隔壁上にインクの濡れ残りが発生してしまうことが分かる。

The receding contact angle is determined by the balance between the surface energy of the ink material composition and the bulkhead material composition. When the back contact angle is 15 ° or more like ink A and ink B, there is no wet residue on the partition wall after ink shrinkage, but the back contact angle is 15 ° or less like ink C and ink D. Then, it can be seen that the ink remains wet on the partition wall.

Under the above-mentioned material conditions, as shown in FIG. 10C, the light emitting layer 21 is not formed on the top of the first partition wall 23B, and the light emitting layer 21 has a shape that fits in the first partition wall 23B. With this configuration, it is possible to completely prevent unintended light from being emitted from other than the light emitting region of the light emitting layer 21.

(Example 3)
Next, the color conversion device 20C according to the third modification will be described with reference to FIGS. 11A to 11C. 11A is a plan view of the color conversion device 20C according to the third modification, FIG. 11B is a sectional view taken along line XIB-XIB of FIG. 11A, and FIG. 11C is a sectional view taken along line XIC-XIC of FIG. 11A. Is.

In the color conversion device 20 according to the above embodiment, the region surrounded by the second partition wall 24 includes one region surrounded by the first partition wall 23, but the color conversion device 20C in the present modification includes the region surrounded by the first partition wall 23. As shown in FIGS. 11A to 11C, the region surrounded by the second partition wall 24C includes two or more regions surrounded by the first partition wall 23C. Specifically, in this modification, one of the regions surrounded by the second partition wall 24C includes four regions surrounded by the first partition wall 23C. Further, as shown in FIG. 11C, pixels of different colors are separated by a second partition wall 24C.

According to the color conversion device 20C according to the present modification, the ink can be applied to a plurality of pixels at once on the line, so that the film thickness uniformity between the pixels is improved. Further, in general, there are variations in the volume of ejected droplets due to variations in nozzle processing between the nozzles of the inkjet head, but according to the color conversion device 20C according to this modification, a plurality of pixels are used in a plurality of nozzles. Since the light emitting layer 21 of the above can be formed, the variation between the nozzles is averaged. As a result, the uniformity of the film thickness between pixels is dramatically improved.

In this modification, the diameter of the region surrounded by the first partition wall 23C and the length of the second partition wall 24C in the minor axis direction are the same, but are not limited to this. Specifically, as shown in FIG. 12, the region surrounded by the first partition wall 23C and the region surrounded by the second partition wall 24C may be in the form of a double circle in a plan view. Specifically, the region surrounded by the second partition wall 24C may be larger than the region surrounded by the first partition wall 23C on both the long axis and the short axis.

(Other variants)
The color conversion device, the micro LED display panel, and the like according to the present disclosure have been described above based on the embodiments and the modifications 1 to 3, but the present disclosure is limited to the embodiments and the modifications 1 to 3. It's not something.

For example, in the above-described embodiments and modifications 1 to 3, the planar view shape of the region surrounded by the first partition wall 23, 23B or 23C that defines the light emitting region where the light emitting layer 21 emits light is not limited to a circle. It may be a polygon such as a quadrangle or another shape such as an oval. Similarly, the plan view shape of the region surrounded by the second partition wall 24 that defines the formation region (ink coating region) on which the light emitting layer 21 is formed is not limited to an ellipse, but is not limited to an oval It may be in the shape of.

Further, in the above-described embodiments and modifications 1 to 3, the blue light emitting layer 21b does not contain the quantum dot material, but the present invention is not limited to this. That is, the blue light emitting layer 21b may contain a quantum dot material. In this case, the blue light emitting layer 21b contains a quantum dot material that emits blue light when irradiated with excitation light such as ultraviolet light.

In addition, the above-described embodiments and modifications 1 to 3 can be obtained by performing various modifications that can be considered by those skilled in the art, and the embodiments and modifications 1 to 3 without departing from the spirit of the present disclosure. Also included in the present disclosure are forms realized by any combination of components and functions.

The light emitting material may not be a quantum dot material but may be another light emitting material.

The technique of the present disclosure can be widely used in various devices having a functional film such as a color conversion device and a light emitting layer such as a micro LED display panel.

1 Micro LED display panel 10 Light emitting device 11, 26 Light emitting body 12, 22, 22X Board 13 Partition wall 20, 20A, 20B, 20C, 20Z Color conversion device 21 Light emitting layer 21r Red light emitting layer 21g Green light emitting layer 21b Blue light emitting layer 21Y Light emitting Layers 23, 23B, 23C First partition 24, 24B, 24C Second partition 24X, 24Y partition 25 Color filter 25r Red color filter 25g Green color filter 25b Blue color filter 30 Partition material 40, 40r, 40g, 40Y Ink 100 Photomask 101 Shield 102 First opening 103 Second opening

Claims (19)

With the board
A light emitting layer located on the substrate and containing a light emitting material,
A first partition wall that comes into contact with the light emitting layer and defines a light emitting region in which the light emitting layer emits light.
It has a second partition wall that comes into contact with the light emitting layer and defines a formation region in which the light emitting layer is formed.
A color conversion device in which the contact area between the light emitting layer and the first partition wall is larger than the contact area between the light emitting layer and the second partition wall. The color conversion device according to claim 1, wherein the region surrounded by the second partition wall includes two or more regions surrounded by the first partition wall. The first partition wall and the second partition wall are provided on one surface of the substrate.
The color conversion device according to claim 1 or 2, wherein the first distance from the substrate to the top of the first partition wall is shorter than the second distance from the substrate to the top of the second partition wall. The static contact angle of the top of the first partition wall with respect to the ink forming the color conversion layer is smaller than the static contact angle of the top of the second partition wall.
The color conversion device according to claim 1 to 3. The static contact angle between the top of the first partition wall and the top of the second partition wall with respect to the ink forming the color conversion layer is 40 ° or more and 70 ° or less, and the side portion of the first partition wall and the first partition wall. The static contact angle of the side of the second partition wall shall be 5 ° or more and 40 ° or less.
4. The color conversion device according to claim 4. The receding contact angle of the top of the second partition wall with respect to the ink forming the color conversion layer shall be 15 ° or more.
The color conversion device according to any one of claims 1 to 5. The first distance is 3 μm or more and 7 μm or less.
The color conversion device according to any one of claims 1 to 6, wherein the second distance is 6 μm or more and 8 μm or less. The light emitting layer is formed by curing an ink containing the light emitting material.
The color conversion device according to any one of claims 1 to 7, wherein the static contact angle of the top of the first partition wall with respect to the ink is larger than the static contact angle of the side surface of the first partition wall with respect to the ink. The color conversion device according to any one of claims 1 to 8, wherein two first partition walls are arranged so as to face each other in one region surrounded by the second partition wall. The color conversion device according to claim 9, wherein the shape sandwiched between the two first partition walls is cylindrical. The color conversion device according to any one of claims 1 to 9, wherein the first partition wall is a columnar body, and is written on the side surface of the second partition wall. The color conversion device according to any one of claims 1 to 11, wherein the region surrounded by the second partition wall has a flat shape in a plan view. The color conversion device according to claim 12, wherein the flat region is inclined with respect to the substrate in a plan view. The color conversion device according to any one of claims 1 to 13, wherein the first partition wall and the first partition wall contain a fluorine material. The color conversion device according to claim 14, wherein the fluorine material is non-uniformly contained in the first partition wall and the first partition wall. The color conversion device according to any one of claims 1 to 15.
A micro LED display panel comprising a light emitting device that emits light incident on the color conversion device. The first step of forming a first partition wall on the substrate that defines the light emitting region where the light emitting layer emits light,
A second step of forming a second partition wall on the substrate, which defines a formation region in which the light emitting layer is formed,
The region surrounded by the second partition wall includes a third step of applying an ink containing a light emitting material to form the light emitting layer.
In the first step and the second step, the first distance from the substrate to the top of the first partition wall is shorter than the second distance from the substrate to the top of the second partition wall. A method for manufacturing a color conversion device that forms the first partition wall and the second partition wall. In the third step, the ink is applied using an inkjet method.
The area surrounded by the second partition wall has a flat shape in a plan view.
The method for manufacturing a color conversion device according to claim 17, wherein the ink application direction is a direction perpendicular to the long axis direction of the region surrounded by the second partition wall. A method for manufacturing a micro LED display panel using a color conversion device manufactured by the method for manufacturing a color conversion device according to claim 17 or 18.
A method for manufacturing a micro LED display panel, which comprises a step of bonding the color conversion device and a light emitting device that emits light incident on the color conversion device.

Images