TW202101785A - Color conversion device, micro light emitting diode display panel, manufacturing method of color conversion device, and manufacturing method of micro light emitting diode display panel capable of both inhibiting deterioration of light emission property and reducing cost - Google Patents

Abstract

A color conversion device comprises a substrate and a light emission layer disposed on the substrate containing light emission material. The color conversion device comprises first separation walls in contact with the light emission layer and defining light emission zones of the light emission layer for emitting light; and, second separation walls in contact with the light emission layer and defining forming zones for forming the light emission layer; wherein the contact area between the light emission layer and the first separation walls is greater than that between the light emission layer and the second separation walls. Thus, the present invention may provide a color conversion device capable of both inhibiting deterioration of light emission property and reducing cost.

Description

Color conversion device, micro-light-emitting diode display panel, manufacturing method of color conversion device, and manufacturing method of micro-light-emitting diode display panel

The present disclosure relates to a color conversion device, a micro-light-emitting diode display panel, a manufacturing method of the color conversion device, and a manufacturing method of the micro-light-emitting diode display panel.

As the next-generation display panel, the development of a quantum dot display panel with a light-emitting layer composed of quantum dot materials is continuing. Quantum dots are special semiconductors with very small sizes ranging from 2 nanometers to 10 nanometers (equivalent to 10 to 50 cents of atoms). This tiny size substance has different properties from ordinary substances. For example, quantum dots can control the bandgap by changing the particle size. In addition, since the emission peak wavelength of quantum dots depends on the energy band gap, the emission peak wavelength of quantum dots can be adjusted very precisely. That is, the emission peak wavelength of quantum dots can be changed by changing the particle diameter. Specifically, the emission peak wavelength of quantum dots shifts to the shorter wavelength side as the particle diameter becomes smaller, and shifts to the longer wavelength side as the particle diameter becomes larger. In addition, since the emission spectrum of the quantum dot has a steep peak, the half width of the emission peak wavelength of the quantum dot is very small. Specifically, the emission spectrum of quantum dots is several tens of nanometers or less.

That is, as long as the quantum dot material is used as the material of the red light-emitting layer, the green light-emitting layer, and the blue light-emitting layer, the half width of the emission peak wavelength of each of red light, green light, and blue light can be reduced. In this way, a display panel with high color gamut characteristics can be realized. As a result, as long as the quantum dot material is used in the light-emitting layer, the performance of the display panel can be dramatically improved.

In addition, since the brightness of the quantum dot display panel is very high, it is excellent in visibility outdoors. Therefore, the quantum dot display panel is suitable for mobile phones, or vehicle-mounted displays, or head-mounted displays. In particular, since it is predicted that the above-mentioned display will require a pixel resolution of 350ppi (pixel per inch) or more in the future, the utilization of quantum dot display panels is expected.

In addition, in recent years, a method of manufacturing a display panel using an inkjet method has attracted attention. For example, in an organic EL display panel, when the red light-emitting layer, the blue light-emitting layer, and the green light-emitting layer or the hole injection layer are formed, the ink containing the organic EL material is applied to the In the area (opening) surrounded by the partition wall of the bank, the ink solvent is dried. That is, the light-emitting layer and the like are formed by the inkjet method. This makes it possible to form a light-emitting layer and the like in the air, compared to forming a light-emitting layer or the like by a conventional vacuum deposition method.

In addition, the organic EL material constituting the light-emitting layer is very expensive. For example, when the light-emitting layer is formed by a vacuum evaporation method, the organic EL material adheres to the wall surface of the chamber of the evaporation equipment. Therefore, many waste materials of organic EL materials are generated, and the use efficiency of the materials becomes low. As a result, the cost of the organic EL display panel will increase. In contrast, when the light-emitting layer is formed by the inkjet method, since the light-emitting layer can be formed in the atmosphere, the light-emitting layer can be formed in an energy-saving state. In addition, according to the inkjet method, the ink containing the organic EL material can be separately applied and applied only to a predetermined place. Thereby, a low-cost organic EL display panel can be realized.

In recent years, there has been a widespread discussion of inks containing the above-mentioned quantum dot materials, similarly to inks containing organic EL materials, about the production method of separate coating using the inkjet method. In terms of representative quantum dot materials, inorganic materials such as cadmium-selenium or indium-phosphorus can be used as core materials. In addition, as the shell layer around the core material of the quantum dot material, for example, a material such as zinc sulfide is used. In addition, in order to achieve stability as an ink, there are also quantum dot materials that can form ligands around the shell.

For example, International Patent Publication No. 2016/010077 (hereinafter, referred to as "Patent Document 1") discloses a method of manufacturing a device used in an organic EL display panel or a quantum dot display panel using an inkjet method.

FIG. 13 shows a cross-sectional view of the device disclosed in Patent Document 1.

As shown in FIG. 13, the apparatus disclosed in Patent Document 1 uses an inkjet method to apply ink to a region (opening portion) surrounded by a partition wall 24X formed by applying ink on the substrate 22X. Thereby, a functional film 21X corresponding to the function of the applied ink is formed in the opening. That is, when the device disclosed in Patent Document 1 is used in a display panel, the area surrounded by the partition wall constitutes a pixel (pixel), and the functional film 21X becomes a light-emitting layer.

However, when the device disclosed in Patent Document 1 is used in a display panel, the interval between the regions surrounded by the partition wall 24X that are arranged in the surface of the substrate 22X and become pixels becomes narrow. That is, when it is desired to increase the resolution of the pixel, the ink landing position of the ink discharged to the area surrounded by the partition wall 24X may deviate. As a result, the ink may be mixed into unexpected pixels to cause color mixing.

Hereinafter, a case where the resolution of the pixel of the target display panel is 400 ppi is taken as an example for specific description.

In addition, in such a case, in a device having a light-emitting layer and a partition wall used in a display panel, the distance between pixels and the width of the partition wall become as shown in FIGS. 1A and 1B.

1A is a plan view showing an example of the structure of a device used in a display panel with a pixel resolution of 400 ppi. Fig. 1B is a cross-sectional view taken along line 1B-1B of Fig. 1A. In detail, FIG. 1B shows a situation when ink is discharged to the pixels of the device shown in FIG. 1A. Moreover, FIG. 1B shows a state before forming the light-emitting layer 21Y shown in FIG. 1A.

The display panel shown in FIG. 1A and FIG. 1B has: a light-emitting layer 21Y disposed at positions corresponding to each pixel of red (R), green (G), and blue (B); and a partition wall 24Y surrounding each light-emitting layer 21Y. In addition, the distance between the pixels of the light-emitting layer 21Y of the same color is about 63 μm, and the distance between the pixels of the two light-emitting layers 21Y adjacent to each other in different colors is 21 μm. In addition, the size of each pixel has a diameter of 15 μm, and the width of the partition wall separating two adjacent pixels is 6 μm. In addition, the size of each pixel is designed in consideration of the light-emitting characteristics of the display panel. Therefore, the above-mentioned numerical value is a representative value, and it is not necessarily limited to the above-mentioned numerical value.

In addition, FIG. 1B shows a state where a droplet of the ink 40Y is discharged to an area (pixel) surrounded by the partition wall 24Y when the light-emitting layer 21Y is formed by the inkjet method.

Hereinafter, consider a case where, for example, an inkjet head capable of ejecting ink 40Y with a volume of 1 picoliter (pL) is used to apply ink 40Y to the area surrounded by partition wall 24Y.

The diameter of a droplet of ink 40 with a volume of 1 pL is 12.6 μm. On the other hand, the width of the area where the ink 40Y should be applied is 15 μm as described above. That is, the width of the area where the ink 40Y is applied is almost the same as the size of the droplet of the ink 40Y. Therefore, extremely high precision is required for the accuracy of the drop position of the ink 40Y applied to the pixel. That is, it is practically difficult to form a coating film stably without color mixing. Therefore, the yield rate during device manufacturing decreases. As a result, there is a risk of increasing the cost of the display panel and reducing the light-emitting characteristics caused by color mixing.

In this disclosure, even if the interval between the regions surrounded by the partition wall is narrow, the inkjet method can be used to efficiently form a functional film such as a light-emitting layer. Thereby, it is possible to provide a color conversion device, a micro-light-emitting diode display panel, and the like that can achieve both suppression of reduction in luminescence characteristics and cost reduction.

One aspect of the color conversion device of the present disclosure has: a substrate; a light-emitting layer located on the substrate and containing a light-emitting material; a first partition wall that contacts the light-emitting layer and defines a light-emitting area where the light-emitting layer emits light; and a second partition wall, Contact the light-emitting layer and specify the formation area where the light-emitting layer is formed. In addition, 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.

In addition, one aspect of the micro-light-emitting diode display panel of the present disclosure has: a color conversion device; and a light-emitting device that emits light incident on the color conversion device.

In addition, an aspect of the manufacturing method of the color conversion device of the present disclosure includes a first step: forming a first partition wall on a substrate, and the first partition wall defines a light-emitting region where the light-emitting layer emits light. In addition, it includes: a second step of forming a second partition wall on the substrate, and the second partition wall is a region where the light-emitting layer is formed; and a third step: coating a region surrounded by the second partition wall containing a light-emitting material The ink forms the light-emitting layer. In addition, in the first step and the second step, the first partition wall and the second partition wall are formed such that the first distance from the substrate to the top of the first partition wall becomes longer than the distance from the substrate to the top of the second partition wall. The second distance so far is even shorter.

In addition, one aspect of the manufacturing method of the micro-light-emitting diode display panel of the present disclosure is the manufacturing method of the micro-light-emitting diode display panel using the color conversion device manufactured by the above-mentioned color conversion device manufacturing method, including The step of bonding the color conversion device and the light-emitting device. The light-emitting device emits light incident on the color conversion device.

According to the present disclosure, even if the interval between the regions surrounded by the partition wall is narrow, the inkjet method can be used to efficiently form a functional film such as a light-emitting layer. Therefore, it is possible to provide a color conversion device, a micro-light-emitting diode display panel, and the like that can achieve both suppression of reduction in luminescence characteristics and cost reduction.

Detailed description of the preferred embodiment

Hereinafter, the embodiments of the present disclosure will be described with reference to the drawings. In addition, the embodiments described below are all embodiments showing a specific example of the present disclosure. Therefore, the numerical values, constituent elements, arrangement positions and connection forms of constituent elements, and steps and order of steps shown in the following embodiments are only examples and do not limit the gist of the present disclosure. Accordingly, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims are described as arbitrary constituent elements.

In addition, each figure is a schematic diagram, and it is not necessarily a figure shown strictly. In addition, in each figure, the same symbols are attached to substantially the same components, and repeated descriptions will be omitted or simplified. (Implementation form)

Hereinafter, the embodiments of the present disclosure will be explained separately by using drawings. ＜Micro LED display panel＞

First, the structure of the light emitting diode (Light Emitting Diode) display panel 1 of the embodiment will be described using FIG. 2.

2 is a cross-sectional view of the micro light emitting diode display panel 1 of the embodiment. In addition, the micro-light-emitting diode display panel 1 is a display using micro-order size micro-light-emitting diodes as pixels (pixels).

As shown in FIG. 2, the micro-light-emitting diode display panel 1 of the present embodiment has a light-emitting device 10 and a color conversion device 20 arranged opposite to the light-emitting device 10 and the like.

In addition, the specific manufacturing method will be described later, but the micro-light-emitting diode display panel 1 is manufactured by manufacturing the light-emitting device 10 and the color conversion device 20 in different steps, and then bonding them separately.

In addition, the bonding part of the light-emitting device 10 and the color conversion device 20 is covered with a sealing material. Thereby, it is suppressed that moisture and oxygen from the outside penetrate into the micro light emitting diode display panel 1. As a result, the degradation of the micro light emitting diode display panel 1 is suppressed, and the micro light emitting diode display panel 1 with high reliability is realized.

The light emitting device 10 emits light incident to the color conversion device 20. The light-emitting device 10 of this embodiment is a blue light-emitting device that emits blue light. Specifically, the light emitting device 10 is, for example, an LED device composed of LEDs. In addition, the light-emitting device 10 may be an organic EL device composed of organic EL (Electro Luminescence), etc., or an inorganic EL device that emits light using inorganic materials.

In addition, as shown in FIG. 2, the light-emitting device 10 of this embodiment has a substrate 12 and a light-emitting body 11 and the like arranged on the substrate 12. ＜Illuminant 11＞

The luminous bodies 11 are arranged in plural on the substrate 12. The light-emitting body 11 is provided for each pixel of the micro light-emitting diode display panel 1. That is, one light-emitting body 11 is provided corresponding to one pixel in the micro-light-emitting diode display panel 1.

The luminous body 11 is a light source that emits light. The light-emitting body 11 of this embodiment is a blue light-emitting body that emits blue light. In such a case, it is preferable to use a blue LED as the light-emitting body 11 from the viewpoint of cost, etc., but it is not limited to this. For example, an organic EL device may be used as the light-emitting device 10. In this case, the light-emitting body 11 is an organic EL light-emitting body composed of an organic EL film. ＜Board 12＞

As long as the substrate 12 is an insulating material, a substrate of any material can be used. Specifically, as the substrate 12, a metal base substrate such as a resin substrate using an insulating resin material as a base material, an aluminum alloy substrate having an insulating coating on the surface, or the like can be used. In addition, as the substrate 12, for example, a ceramic substrate composed of a ceramic material, a glass substrate composed of a glass material, or the like can be used.

In addition, the substrate 12 can be a translucent substrate having translucency according to the extraction direction of the light emitted from the luminous body 11, or a translucent substrate that does not transmit light can be used. When a translucent substrate is used, the substrate 12 is a transparent substrate such as a transparent resin substrate or a glass substrate. In addition, the substrate 12 may be a rigid substrate or a soft substrate.

In addition, the substrate 12 may be provided with a white insulating film such as a white photoresist formed on the surface of the substrate 12. Thereby, the insulation withstand voltage of the substrate 12 and the light extraction efficiency can be improved. ＜Light-emitting device 10＞

The light emitting device 10 of this embodiment has a partition wall 13. The partition wall 13 is made of, for example, a black or white resin material.

The partition wall 13 is provided to surround each luminous body 11. The partition wall 13 can prevent the light emitted from the luminous body 11 from leaking to adjacent pixels.

In addition, the light-emitting device 10 may also include a driving transistor for controlling the light emission of the light-emitting body 11. In addition, for the blue LED used as the light-emitting body 11, a blue LED that has been manufactured in another step may be mounted on the substrate 12. In addition, the blue LED may be directly formed on the substrate 12. Moreover, for example, when an organic EL device is used as the light-emitting device 10, a vacuum vapor deposition method or an inkjet method may be used, and an organic EL film may be directly formed on the substrate 12 as the light-emitting body 11. ＜Color conversion device 20＞

Next, the color conversion device 20 will be described using FIGS. 3A and 3B while referring to FIG. 2.

Fig. 3A is a plan view of the color conversion device 20 of the embodiment. FIG. 3B is a cross-sectional view of the color conversion device 20 in the line 3B-3B of FIG. 3A.

The color conversion device 20 has a function of converting light incident from the light-emitting device 10 to the color conversion device 20 into a wavelength of a predetermined color, for example. The color conversion device 20 has a plurality of light-emitting layers 21 and functions as a wavelength conversion layer. Specifically, the light-emitting layer 21 of the color conversion device 20 constitutes a wavelength conversion layer, and converts 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.

The color conversion device 20 of this embodiment has a red light emitting layer 21r, a green light emitting layer 21g, and a blue light emitting layer 21b as the light emitting layer 21. The red light-emitting layer 21r has a function of converting the wavelength of the blue light emitted from the light-emitting device 10 into the wavelength of red. The green light-emitting layer 21g has a function of converting the wavelength of blue light emitted from the light-emitting device 10 into a green wavelength. The blue light-emitting layer 21b has a function of directly transmitting blue light emitted from the light-emitting device 10. ＜Light-emitting layer 21＞

The plurality of light-emitting layers 21 of the color conversion device 20 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 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 arranged in a one-to-one correspondence relationship with each other. That is, each light-emitting layer 21 of the plurality of light-emitting layers 21 is provided corresponding to one pixel in the micro light-emitting diode display panel 1.

The red light emitting layer 21r of the pixel corresponding to the red color and the green light emitting layer 21g of the pixel corresponding to the green color of the present embodiment are composed of a quantum dot material (light emitting material). As the quantum dot material, for example, cadmium-selenium-based or indium-phosphorus-based, copper-indium-sulfur, silver-indium-sulfur, and perovskite structure materials can be used.

In addition, 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 has been dispersed. In addition, the concentration of the quantum dot material in the red light-emitting layer 21r and the green light-emitting layer 21g is preferably in the range of 5 weight percent or more and 50 weight percent or less.

In addition, the red light-emitting layer 21r contains a quantum dot material that emits red light. The quantum dot material included in the red light-emitting layer 21r of the present embodiment is excited by light of a blue wavelength emitted from the light-emitting device 10 to emit red light. That is, when the light of the blue wavelength is irradiated to the red light-emitting layer 21r, the light of the blue wavelength is converted into the red wavelength. Thereby, red light is emitted from the red light-emitting layer 21r.

Similarly, the green light-emitting layer 21g contains a quantum dot material that emits green light. The quantum dot material included in the green light-emitting layer 21g of this embodiment is excited by light of a blue wavelength emitted from the light-emitting device 10 to emit green light. That is, when the light of the blue wavelength is irradiated to the green light-emitting layer 21g, the light of the blue wavelength is converted into the green wavelength. Thereby, green light is emitted from the green light-emitting layer 21g.

In addition, the blue light-emitting layer 21b of the present embodiment is composed of a resin film containing no quantum dot material. Therefore, when light of a blue wavelength is irradiated to the blue light-emitting layer 21b, blue light is directly emitted from the blue light-emitting layer 21b.

Here, 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, resin such as acrylic or epoxy. In addition, 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 preferable to use an ultraviolet curable resin that is cured by ultraviolet irradiation.

In addition, the light-emitting layer 21 may have diffusion particles (scattering particles) having a characteristic of scattering light 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 such a case, the blue light-emitting layer 21b of this embodiment includes only the quantum dot material and the diffusion particles among the diffusion particles.

In this case, as the diffusion particles, for example, titanium oxide particles, zirconium oxide particles, or hollow silica particles in which the inside of the particles becomes hollow, or the like can be used. The particle size of the diffusion particles is, for example, in the range of 50 nm or more and 1000 nm or less. In addition, the diffusion particles are contained in each light-emitting layer 21 at a concentration of several weight percentages, for example. When the light-emitting layer 21 contains diffusion particles, the light path length of the blue light traveling in the light-emitting layer 21 is increased by scattering. Thereby, the number of times the blue light is irradiated to the quantum dot material with wavelength conversion function in the light-emitting layer 21 will increase. As a result, the wavelength conversion efficiency of the light-emitting layer 21 increases.

In addition, the light-emitting layer 21 may further include particles that absorb moisture. Thereby, the deterioration of the light-emitting layer 21 caused by the absorption of moisture can be suppressed.

The color conversion device 20 further has a substrate 22, and the light-emitting layer 21 is disposed on the substrate 22. Specifically, the light-emitting layer 21 is disposed on one side of the substrate 22, that is, the front side. ＜Substrate 22＞

Any material can be used for the substrate 22 as long as it is an insulating material. For example, as the substrate 22, a resin substrate, a metal base substrate, a ceramic substrate, a glass substrate, or the like can be used.

In addition, the substrate 22 can be a translucent substrate having translucency according to the direction of light extraction, or a translucent substrate that does not transmit light can be used. 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. In addition, the substrate 22 may be a rigid substrate or a soft substrate.

In this embodiment, as the substrate 22, for example, a glass substrate is used. In such a case, in order to prevent the light emitted from the light emitting layer 21 from penetrating the substrate 22, it is preferable to provide a light shielding film having a light shielding property on the substrate 22. Specifically, as the light-shielding film, for example, a light-reflecting film having light reflectivity may be formed on the front surface of the substrate 22 (the surface on which the light-emitting layer 21 is provided). In addition, the light reflection film may be constituted by a white film such as a white photoresist formed of a white insulating resin material or the like. Alternatively, as the light reflection film, a metal film having light reflectivity may be formed on the back surface of the substrate 22. Specifically, a metal film made of silver-palladium-copper alloy or the like may be formed on the back surface of the substrate 22.

In addition, the color conversion device 20 of this embodiment 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 one of the front surfaces of the substrate 22 in the same way as the light-emitting layer 21. ＜Partition wall＞

The first partition wall 23 and the second partition wall 24 are provided to surround the light emitting layer 21.

The first partition wall 23 defines a light-emitting area where the light-emitting layer 21 emits light. The second partition wall 24 defines a formation area where the light-emitting layer 21 is formed.

The light-emitting layer 21 of this embodiment is formed by applying ink using an inkjet method. Therefore, the second partition wall 24 becomes an application area (ink application area) where ink is applied.

The second partition wall 24 is used in common for a plurality of light-emitting layers 21 to be integrated. The second partition wall 24 has a plurality of openings, and the plurality of openings are formed as an area surrounded by the second partition wall 24 and corresponding to each of the plurality of light-emitting layers 21. That is, the light-emitting layer 21 is formed in each of 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. In other words, 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, for example, an elliptical shape (elliptical cylinder shape), or a circular shape (cylindrical shape) as shown in FIG. 3A plus two crescent shapes (pillars) facing each other. Shape body) after the shape. With this shape, openings can be formed at a high density on the front surface of the substrate 22, and the distance between the openings can be maintained. Thereby, it is possible to prevent the occurrence of color mixing between the plurality of light-emitting layers 21. In addition, the region formed by the first partition wall 23 has a circular shape (columnar shape). Thereby, the light emission by the light-emitting layer 21 can be homogenized.

In addition, the first partition wall 23 is formed in the long side direction (long axis direction) of the substrate 22 in the two directions of the side surface facing the opening of the second partition wall 24, for example, in the shape of a crescent column (column Shape). Thereby, the volume (volume) of the opening can be ensured, and the space where the light-emitting layer 21 is mainly formed can be made into a cylindrical shape. As a result, a uniform amount of light emission from the light-emitting layer 21 can be ensured.

In each pixel, the area (opening portion) surrounded by the second partition wall 24 has, for example, a flat shape in a plan view. Specifically, as shown in FIG. 3A, the area (opening portion) surrounded by the second partition wall 24 in this embodiment has a racetrack-like oblong shape in a plan view. In addition, the area surrounded by the first partition wall 23 located inside the second partition wall 24 has a circular shape in a plan view.

In addition, as shown in FIG. 2, in each pixel, the first partition wall 23 is formed to contact the inner wall surface of the second partition wall 24. That is, in the area surrounded by the second partition wall 24 in this embodiment, only one area surrounded by the first partition wall 23 is included. In addition, one light-emitting layer 21 is provided in the area surrounded by the second partition wall 24.

In addition, the film thickness of the first partition wall 23 in this embodiment 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 23 a of the first partition wall 23 is shorter than the second distance from the substrate 22 to the top 24 a 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, 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, preferably 6 μm or more and 8 μm or less. That is, when the first partition wall 23 is too low, the light emission of the light-emitting layer disposed on the first partition wall 23 cannot be ignored. Therefore, the film thickness of the first partition wall 23 is preferably set as close as possible to the film thickness of the second partition wall 24.

In addition, each light-emitting layer 21 is in contact with the corresponding first partition wall 23 and the second partition wall 24, respectively. 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 formed so as to be in contact with the first partition wall 23 and the second partition wall 24, respectively. Thereby, compared with the configuration in which the light-emitting layer 21 is in contact with only one of the first partition wall 23 and the second partition wall 24, the light-emitting layer 21 and the partition wall surrounding the light-emitting layer 21 (the first partition wall 23 And the contact area of the second partition wall 24). As a result, the adhesion between the light-emitting layer 21 and the partition wall is improved. In particular, when the substrate 22 is a flexible substrate, the reliability of the color conversion device 20 such as peeling due to deformation or the like is improved.

The first partition wall 23 is formed to surround the red light-emitting layer 21r, the green light-emitting layer 21g, and the blue light-emitting layer 21b in the opening of the corresponding second partition wall 24. Thereby, the light-emitting layer 21 in the area (opening) surrounded by the second partition wall 24 contacts the inner wall surface of the first partition wall 23 and the entire surface of the top 23a, and also contacts the upper part of the second partition wall 24. Wall surface.

In addition, in this embodiment, the film thickness of the first partition wall 23 is formed to be thinner than the film thickness of the second partition wall 24. That is, the film thickness of the light emitting layer 21 located at the top 23a of the first partition wall 23 becomes thinner than other parts. Therefore, the light-emitting layer 21 located at the top 23a of the first partition wall 23 hardly functions as a wavelength conversion layer, and therefore does not emit light. In addition, even if there is a little light, the emitted light is blocked by the first partition wall 23. Therefore, light will not be captured to the outside of the light-emitting layer 21. Thereby, only the area defined inside the first partition wall 23 contributes to light emission.

With the structure of the color conversion device 20 described above, the formation area (ink application area) for forming the light-emitting layer 21 can be widely secured. In addition, the light-emitting area where the light-emitting layer 21 emits light may be prescribed to a predetermined size. As a result, the inkjet method can be used to form the light-emitting layer 21 as a functional film with high quality and low cost.

In addition, each of the first partition wall 23 and the second partition wall 24 may be composed of any one of an inorganic material and an organic material as long as it is an insulating material. As an example, for example, the first partition wall 23 and the second partition wall 24 are formed using a photosensitive resin cured by ultraviolet rays. In such a case, the first partition wall 23 and the second partition wall 24 are preferably formed of the same resin material.

In addition, in order to efficiently capture the light emitted from the light-emitting layer 21, the first partition wall 23 that defines the light-emitting area of the light-emitting layer 21 is preferably formed of a white material. For example, as the first partition wall 23, a white photoresist or the like can be used.

On the other hand, the second partition wall 24 that defines the formation area of the light-emitting layer 21 is preferably formed of a material that has lower wettability than the first partition wall 23 and has liquid repellency to the applied ink. Therefore, for example, as the second partition wall 24, in order to impart liquid repellency, a resin containing a functional group containing a fluorine atom, such as a fluorine resin, is used. In addition, the fluororesin is not particularly limited as long as it is a fluororesin having fluorine atoms in at least a part of the repeating units of the fluororesin polymer. Specifically, examples of the fluororesin include fluorinated polyolefin resins, fluorinated polyimide resins, and fluorinated polyacrylic resins.

In addition, as described above, the second partition wall 24 of the present embodiment has lower wettability than the first partition wall 23. In other words, the first partition wall 23 is made of a material with 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 is preferably larger than the contact area between the light-emitting layer 21 and the second partition wall 24. Thereby, the adhesion of the light-emitting layer 21 to the first partition wall 23 can be improved. ＜Color filter 25＞

Hereinafter, another configuration of the color conversion device of the embodiment will be described using FIG. 4.

Fig. 4 is a cross-sectional view showing another configuration of the color conversion device of the embodiment.

The other configuration of the color conversion device is a configuration in which a color filter 25 is further provided in each light-emitting layer 21.

That is, as shown in FIG. 4, for example, a red color filter 25r is provided in the red light-emitting layer 21r, a green color filter 25g is provided in the green light-emitting layer 21g, and a blue color filter 25b is provided in the blue light-emitting layer 21b. .

Since only the desired wavelength can be transmitted through the color filter 25, the color reproducibility of the color conversion device can be improved. Specifically, with respect to the blue light emitted by the light emitting device 10 that emits blue light, 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 improved, so the color reproducibility is improved. Will improve.

Moreover, by providing the color filter 25, the luminous efficiency of the light-emitting layer 21 can be improved.

In addition, the color conversion device does not necessarily need to be provided with the above-mentioned color filter 25, as long as it is appropriately provided depending on the application or the like. ＜Manufacturing method of micro light emitting diode display panel＞

Next, the manufacturing method of the micro light emitting diode display panel 1 of the embodiment will be described.

Specifically, the manufacturing method of the micro light-emitting diode display panel 1 of this 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 . [Method of Manufacturing Light-emitting Device]

First, a method of manufacturing the light-emitting device 10 will be described.

For example, the light-emitting device 10 first transfers the blue light-emitting luminous body 11 that has been manufactured in another step onto the substrate 12. Thereby, the light-emitting device 10 in which the light-emitting body 11 is arranged on the substrate 12 can be obtained. In this case, a partition wall 13 formed by photolithography or the like is provided on the substrate 12 so that the light emitted from the light-emitting body 11 does not leak to adjacent pixels. The partition wall 13 is arranged to surround each luminous body 11. [Method of manufacturing color conversion device]

Next, the manufacturing method of the color conversion device 20 will be described using FIGS. 5A to 5D.

5A to 5D are diagrams illustrating the manufacturing flow in the manufacturing method of the color conversion device 20 of the embodiment. In addition, FIGS. 5A, 5B, 5C, and 5D respectively show the substrate preparation step, the first partition wall formation step (first step), the second partition wall formation step (second step), and the light emitting layer formation step. (Step 3).

Specifically, the substrate preparation step of the method of manufacturing the color conversion device 20 is a step of preparing the substrate 22 (substrate preparation step) as shown in FIG. 5A. As shown in FIG. 5B, the first partition wall forming step is a step of forming a first partition wall 23 on the substrate 22, and the aforementioned first partition wall 23 is a light-emitting region where the light-emitting layer 21 emits light. As shown in FIG. 5C, the second partition wall forming step is a step of forming a second partition wall 24 on the substrate 22, and the aforementioned second partition wall 24 defines a formation area where the light-emitting layer 21 is formed. In addition, as shown in FIG. 5D, the light-emitting layer forming step is a step of forming the light-emitting layer 21 by applying ink containing a quantum dot material to the area surrounded by the second partition wall 24.

In addition, in the color conversion device 20 of this embodiment, in the first partition wall forming step and the second partition wall forming step, the first partition wall 23 and the second partition wall 24 are formed from the substrate 22 to the first partition wall 23 The first distance from the top 23a (refer to FIG. 2) of the second partition wall is shorter than the second distance from the substrate 22 to the top 24a (refer to FIG. 2) of the second partition wall 24.

Hereinafter, specific examples of each step of the first partition wall formation step, the second partition wall formation step, and the light-emitting layer formation step will be described individually. (Substrate preparation steps)

In the substrate preparation step, as shown in FIG. 5A, the substrate 22 is prepared. In this embodiment, as the substrate 22, a glass substrate is prepared. (The 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 is formed by, for example, a photolithography process using photosensitive resin.

Specifically, first, using a coating method such as a spin coating method or a slit coating method, a photosensitive resin that is a negative material hardened by exposure to ultraviolet light is coated on the substrate 22. Thereby, a coating film of photosensitive resin is formed on the substrate 22. At this time, the coating conditions of the photosensitive resin are adjusted by the number of revolutions of the spin coating method or the scanning speed of the slit coating method in accordance with the required film thickness.

Next, using a hot plate or the like, pre-bake the coating film to dry the solvent component. Then, the coating film is exposed with ultraviolet light through the photomask in which the desired pattern has been formed. In addition, the photosensitive resin includes a negative type material that hardens at the exposed part irradiated with the ultraviolet light, and a positive type material that hardens the unexposed part of the ultraviolet light, but either material can be used.

Secondly, according to the type of photosensitive resin used, use an appropriate developer to remove the coating film from the uncured part. Then, the remaining pattern of the coating film is post-baked in a curing oven or the like. Thereby, as shown in FIG. 5B, the first partition wall 23 having a predetermined shape is formed on the substrate 22.

In more detail, in this embodiment, as described above, as the material of the first partition wall 23, a photosensitive white resin with high reflectance is used. In addition, as the photosensitive white resin, a photosensitive resin obtained by adding inorganic substances such as white titanium oxide particles to acrylic resin or epoxy resin can be used.

In addition, a white resin was applied to the substrate 22 by a slit coating method, and was heated at 80° C. for 30 minutes on a hot plate to perform prebaking.

Next, ultraviolet light with a wavelength of 365 nm is irradiated to harden the white resin. At this time, the exposure amount of ultraviolet rays was set to 500 mJ/cm ² .

Next, the white resin was developed with a developer solution. Specifically, as a developing solution, 1wt% Na ₂ CO ₃ was used to develop a white resin by spray coating for 60 seconds.

Then, the white resin was post-baked at 150°C for 60 minutes in a curing oven. Thereby, a first partition wall 23 made of white resin with a film thickness of 5 μm was formed.

In addition, in the above-mentioned embodiment, although the example which used the white resin for the 1st partition wall 23 was demonstrated, it is not limited to this. For example, in order to improve weather resistance, a yellow resin can also be used. In addition, the first partition wall 23 may be composed of two-layer resin. Specifically, it is composed of two layers in which the lower part of the first partition wall 23 is black and the upper part of the first partition wall 23 is white. Thereby, the contrast of the luminous color in the luminescent layer 21 can be improved. (Second Partition Wall Formation Step)

In the second partition wall forming step, the second partition wall 24 is formed outside the first partition wall 23.

Specifically, similarly to the first partition wall 23, the second partition wall 24 is formed on the outside of the first partition wall 23 as shown in FIG. 5C by a photolithography process using a photosensitive resin. At this time, the second partition wall 24 is formed such that the film thickness of the second partition wall 24 becomes thicker than the film thickness of the first partition wall 23. Thereby, as described above, the area surrounded by the second partition wall 24 is formed in a flat shape (see FIG. 3A) in a plan view.

In addition, in this embodiment, as the material of the second partition wall 24, fluorine-containing acrylic resin containing fluorine is used. Specifically, as the fluorine-containing acrylic resin, a material having the following characteristics is used: fluorine is unevenly distributed on the surface by exposure. Thereby, liquid repellency is provided to the surface of the second partition wall 24.

Here, the contact angle for evaluating the liquid repellency will be described.

Generally speaking, when a liquid is dropped on a solid surface, the liquid will round due to its own surface tension. At this time, the relationship shown in (Equation 1) called Young's formula will hold. γ _s ＝γ _L ×cosθ＋γ _SL …(Equation 1)

γ _s : surface tension of solid, γ _L : surface tension of liquid, γ _SL : interfacial tension of solid and liquid.

At this time, the angle θ formed by the tangent of the droplet and the solid surface is called the contact angle. Among the contact angles, the contact angle when the liquid is stationary on a solid and reaches an equilibrium state is called the static contact angle. On the other hand, the state of the interface movement between the liquid and the solid, that is, the contact angle of the dynamic state of the interface movement of the liquid drop is called the advancing contact angle and the receding contact angle.

Specifically, the static contact angle of the second partition wall 24 to the ink in this embodiment is about 50°.

In addition, as described above, the first partition wall 23 of this embodiment is formed by setting the film thickness to 5 μm. In addition, in order to be thicker than the first partition wall 23, the second partition wall 24 was formed by setting the film thickness to 8 μm.

In addition, in the above-mentioned embodiment, although the manufacturing example performed the 2nd partition wall formation step after the 1st partition wall formation step was demonstrated, it is not limited to this. For example, if the first partition wall forming step and the second partition wall forming step are reversed, the second partition wall forming step may be performed first. That is, the first partition wall forming step may be performed after the second partition wall forming step.

In addition, in the above-mentioned embodiment, an example in which the first partition wall 23 and the second partition wall 24 are produced in different steps has been described, but it is not limited to this. For example, the same photosensitive resin material may be used to produce the first partition wall 23 and the second partition wall 24 at the same time in one step by halftone exposure with different transmittance depending on the location.

Hereinafter, another manufacturing method of the first partition wall 23 and the second partition wall 24 performed by halftone exposure will be described using FIGS. 6A to 6C.

FIG. 6A is a diagram illustrating a partition wall material application step in another method of manufacturing the first partition wall 23 and the second partition wall 24 in the color conversion device of the embodiment. FIG. 6B is a diagram illustrating an exposure step in another method of manufacturing the first partition wall 23 and the second partition wall 24. FIG. 6C is a diagram illustrating an etching step in another method of manufacturing the first partition wall 23 and the second partition wall 24.

Another method of manufacturing the first partition wall 23 and the second partition wall 24 is to first form the partition wall material 30 on the substrate 22 using a spin coating method or a slit coating method as shown in FIG. 6A. At this time, as the partition wall material 30, for example, a photosensitive resin material made of a negative type material similar to the first partition wall 23 or the second partition wall 24 described above can be used.

Next, as shown in FIG. 6B, the partition wall material 30 is irradiated with ultraviolet light through the mask 100. Thereby, the partition wall material 30 will be photosensitive and hardened. At this time, the transmittance of the ultraviolet light of the mask 100 is locally changed. That is, by changing the transmittance of ultraviolet light, the degree of hardening of the partition wall material 30 is changed. Specifically, the mask 100 is formed with a shielding portion 101 that shields ultraviolet light, and a first opening 102 and a second opening 103 having different transmittances. At this time, the penetration rate of the second opening 103 is made larger than the penetration rate of the first opening 102. Thereby, the penetration amount of the ultraviolet light penetrating the first opening 102 and the second opening 103 of the photomask 100 changes.

Next, as shown in FIG. 6C, the uncured portion of the partition wall material 30 is etched with a developing solution. At this time, the part where the amount of penetration of ultraviolet light is small will be less hardened. Therefore, the film thickness after the etching of the partition wall material 30 becomes low and formed.

As described above, the first partition wall 23 and the second partition wall 24 with different film thicknesses can be manufactured at the same time by etching by halftone exposure.

In addition, in the above-mentioned manufacturing method, a method using a negative type material that hardens the part irradiated with ultraviolet light is used as an example, but a positive type material that melts the part irradiated with ultraviolet light may be used. In this case, the relationship of the transmittance of the mask 100 will be different. That is, the shielding portion 101 of the aforementioned photomask 100 is used as the first opening portion, and the second opening portion 103 is used as the shielding portion. Moreover, what is necessary is just to make the penetration rate of a 1st opening part higher than the penetration rate of a 2nd opening part. In this way, even if a positive type material is used, the first partition wall 23 and the second partition wall 24 with different film thicknesses can be manufactured simultaneously in one step. (Light-emitting layer formation step)

In the light-emitting layer forming step, first, ink is applied to the substrate 22 on which the first partition wall 23 and the second partition wall 24 have been formed using an inkjet method to form a coating film.

In this embodiment, in the formation of the red light-emitting layer 21r and the green light-emitting layer 21g, the ink in which the quantum dot material has been dispersed at a predetermined concentration is discharged to the area surrounded by the second partition wall 24 by the inkjet method. Inside. On the other hand, in the formation of the blue light-emitting layer 21b, the ink containing no quantum dot material is discharged into the area surrounded by the second partition wall 24 by the inkjet method.

In addition, 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 film thickness after drying and curing the discharged ink becomes a predetermined film thickness. Determines the amount of ink discharged from the nozzles of the inkjet head.

In this embodiment, as the ink, an ink in which a cadmium-selenium-based quantum dot material is dispersed in an acrylic resin is used. As the quantum dot material, a quantum dot material having a particle diameter of 20 nm or more and 30 nm or less is used. In addition, in order to scatter the blue light to obtain the optical path length in the light emitting layer 21, titanium oxide particles are contained in the ink as diffusion particles. Specifically, as the titanium oxide particles, titanium oxide particles having a particle diameter of approximately 100 nm or more and 1000 nm or less are used. The ink having the above-mentioned configuration is applied to the area surrounded by the second partition wall 24 by the inkjet method.

Moreover, in this embodiment, as shown in FIG. 3A, the application direction of the same color ink is a direction perpendicular to the long axis direction of the area surrounded by the second partition wall 24. That is, the printing direction of the same ink is a direction perpendicular to the long axis direction of the pixels arranged in the order of R, G, and B. In addition, the nozzles of the inkjet head for applying ink are separately provided for the red light emitting layer 21r, the blue light emitting layer 21b, and the green light emitting layer 21g. In addition, the arrangement direction of the nozzles of the inkjet head is the same as the long axis direction of the area surrounded by the second partition wall 24. Thereby, even if it is an arrangement pattern of high-resolution pixels with a narrow interval between the regions surrounded by the second partition wall 24, the colors are not mixed, and the ink can be easily applied.

This point will be described below.

Generally, with respect to the ink application direction (printing direction), by adjusting the timing of the ink ejection, it is relatively easy to make the ink drop at a predetermined position. On the other hand, the nozzle arrangement direction of the inkjet head depends on the processing accuracy of the nozzles, so it is very difficult to correct the ink landing position.

Therefore, in this embodiment, the arrangement direction of the nozzles of the inkjet head is made the same as the major axis direction of the area surrounded by the second partition wall 24. Thereby, with respect to the nozzle arrangement direction, the area where the ink can drop is widened, and the amplitude of the allowable ink drop position is increased. Specifically, with respect to the area surrounded by the first partition wall 23 (the light-emitting area where the light-emitting layer 21 emits light), the application area where the ink is applied, that is, the area surrounded by the second partition wall 24 is widened. Thereby, even with a high-resolution pixel arrangement pattern, there is no color mixing, and the ink can be easily applied to a predetermined position area.

Next, the substrate 22 on which the coating film is formed by applying ink is dried. At this time, in order to suppress the drying of the solvent in the nozzle, a solvent with a high boiling point is often used for ink discharged by the inkjet method. Therefore, it is advisable to use reduced-pressure drying for ink drying. When performing reduced-pressure drying, for example, the ink-coated substrate 22 is set in a drying furnace, and the inside of the drying furnace is reduced in pressure with a vacuum pump to reduce the pressure. This promotes the evaporation of the solvent. In this case, the ultimate vacuum of the drying furnace is several Pa, and the holding time is about tens of minutes. However, since the conditions of ultimate vacuum and holding time are different according to the boiling point of the solvent contained in the ink, they are not limited to the above conditions.

In addition, when the discharged ink contains no solvent and uses an ink in which the quantum dot material is dispersed only in the ultraviolet curable resin, drying under reduced pressure may not be performed.

Next, using a hot plate, pre-baking of the coating film was performed at 100°C for about 5 minutes.

Next, ultraviolet light having a wavelength of 365 nm is irradiated to the coating film to harden the coating film. In such a case, the irradiation amount of ultraviolet light is 200 mJ/cm ² or more and 1000 mJ/cm ² or less, for example.

Next, using a curing furnace, post-baking of the coating film is performed at 150°C for about 20 minutes. Thereby, as shown in FIG. 5D, the light emitting layer 21 is formed in each area (opening portion) surrounded by the second partition wall 24.

Specifically, in this embodiment, pre-baking (100°C, 5 minutes), ultraviolet light irradiation (wavelength 365nm, exposure 300mJ/cm ² ), post-baking (150°C, 20 minutes) are performed in order. , The coating film that has been applied to the substrate 22 is cured.

As a result of the above, as shown in FIGS. 3A and 3B, a color conversion device 20 in which a plurality of light-emitting layers 21 are arranged at a predetermined pitch is fabricated on a substrate 22.

In addition, in this 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 area surrounded by the second partition wall 24. It is explained, but it is not limited to this. For example, as described below using FIGS. 7A and 7B, the arrangement direction of the light-emitting layers 21 of the same color is staggered (inclined) with respect to the direction perpendicular to the long axis of the area surrounded by the second partition wall 24 The composition is also possible. At this time, with respect to the edge (long axis direction) of the substrate 22, the inclination angle is preferably 30 degrees to 60 degrees, and more preferably 40 degrees to 50 degrees.

Fig. 7A is a plan view showing another structure of the color conversion device of the embodiment. Fig. 7B is a cross-sectional view of the color conversion device in line 7B-7B of Fig. 7A.

With the configuration shown in FIGS. 7A and 7B, the interval between the regions surrounded by the second partition wall 24 (the interval in the longitudinal direction) can be narrowed. In this way, the number of light-emitting layers 21 can be further increased. That is, a higher-resolution color conversion device can be easily realized. (Effects, etc.)

Next, the function and effect of the color conversion device 20 of this embodiment will be described in comparison with the color conversion device 20Z of the comparative example shown in FIGS. 8A and 8B.

Fig. 8A is a plan view of a color conversion device 20Z of a comparative example. FIG. 8B is a cross-sectional view of the color conversion device 20Z of the comparative example on the line 8B-8B of FIG. 8A.

As shown in FIGS. 8A and 8B, the color conversion device 20Z of the comparative example is compared with the color conversion device 20 of this embodiment in the first partition wall 23 in the predetermined light-emitting area and the second partition wall in the predetermined ink application area. Among 24, the first partition wall 23 is not provided. That is, in the color conversion device 20Z of the comparative example, only the second partition wall 24 exists among the first partition wall 23 and the second partition wall 24.

In the case of such a configuration, the light-emitting area of the light-emitting layer 21 of the color conversion device 20Z of the comparative example is larger than that of the color conversion device 20 of the present embodiment shown in FIGS. 3A and 7A. That is, the size of the pixel that becomes the pixel becomes larger.

Therefore, in the color conversion device 20Z of the comparative example, when the distance between the pixels becomes too short, interference between the luminous colors may occur. In such a case, in the color conversion device 20Z of the comparative example, it is considered that it is necessary to make a design that keeps the distance between the pixels away. Accordingly, in the display using the color conversion device 20Z of the comparative example, since the resolution becomes low, it becomes difficult to realize high-definition image quality.

In contrast, the color conversion device 20 of the present embodiment forms the second partition wall 24 that defines the ink application area and the first partition wall 23 that defines the light-emitting area. Specifically, the first partition wall 23 is formed inside the area surrounded by the second partition wall 24.

With this configuration, the color conversion device 20 of the present embodiment can reduce the light-emitting area where the light-emitting layer 21 emits light even if the range of the ink application area is the same as that of the color conversion device 20Z of the comparative example. Thereby, compared with the color conversion device 20Z of the comparative example, the size of the pixel can be substantially reduced and the resolution can be improved. In other words, as in the present embodiment, even with the color conversion device 20 having pixels arranged with high resolution, the light-emitting layer 21 can be easily formed by the inkjet method without color mixing.

As described above, according to the color conversion device 20 and the micro light emitting diode display panel 1 of this embodiment, even if the interval between the regions (openings) surrounded by the second partition wall 24 is designed to be narrow, they can still The light-emitting layer 21 is easily formed using an inkjet method. That is, the ink can be applied to the opening stably without color mixing. As a result, it is possible to achieve the color conversion device 20 and the micro-light-emitting diode display panel 1 including the color conversion device 20 and the micro-light-emitting diode display panel 1 provided with the color conversion device 20 and the low-cost reduction at the same time. (Modification 1)

Next, the color conversion device 20A of Modification 1 of the present embodiment will be described with reference to FIG. 9.

9 is a cross-sectional view of the color conversion device 20A of Modification 1.

As shown in FIG. 9, the color conversion device 20A of Modification 1 is different from the color conversion device 20 of the above-mentioned embodiment in that the light-emitting body 26 is provided on the substrate 22. Therefore, only the color conversion device 20A of Modification 1 can be used to construct a micro-light-emitting diode display panel.

Specifically, the light-emitting body 26 is composed of a blue light-emitting body that emits blue light such as a blue LED. The light emitting body 26 which is the blue LED is formed by mounting on the substrate 22. In addition, the structure other than this is the same as the color conversion device 20 of the above-mentioned embodiment.

That is, according to the color conversion device 20A of Modification 1, the luminous body 26 can be incorporated into the color conversion device 20A. Therefore, the function of a light-emitting device can be given to the color conversion device 20A. Thereby, instead of attaching the light-emitting device 10 of the embodiment to the color conversion device 20A, only the color conversion device 20A can be used to realize a micro-light-emitting diode display panel. That is, the color conversion device 20A itself can be used as a micro light emitting diode display. As a result, the thickness of the micro light-emitting diode display panel can be reduced. (Modification 2)

Next, the color conversion device 20B of Modification 2 of the present embodiment will be described using FIGS. 10A to 10C.

10A to 10C are diagrams illustrating a method of manufacturing the color conversion device 20B of Modification 2.

The color conversion device 20B of Modification 2 is different from the color conversion device 20 of the above-mentioned embodiment in that the wettability of the top 23Ba of the first partition wall 23B becomes low.

Specifically, in each light-emitting layer 21, the static contact angle of the top 23Ba of the first partition wall 23B to the ink 40 is the same as the static contact angle of the inner wall surface 23Bb (side surface) of the first partition wall 23 to the ink 40 , Or above.

In addition, for the second partition wall 24B, in each light-emitting layer 21, the static contact angle of the top 24Ba of the second partition wall 24B to the ink 40 is set to be greater than that of the inner wall surface 24Bb (side surface) of the second partition wall 24B to the ink 40 The static contact angle is greater.

In addition, in FIGS. 10A and 10B, the red ink 40r is used to form the red light-emitting layer 21r, and the green ink 40g is used to form the green light-emitting layer 21g.

Here, in Modification 2, the static contact angle of the top 23Ba of the first partition wall 23B to the ink 40 is set to C1, the static contact angle of the inner wall surface 23Bb of the first partition wall 23B is set to C2, and the second The static contact angle of the top 24Ba of the partition wall 24B is set to C3, and the static contact angle of the inner wall surface 24Bb of the second partition wall 24B is set to C4. At this time, the color conversion device 20A of Modification 2 is configured such that 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. On the other hand, the static contact angles C2 and C4 are 5° or more and 40° or less.

In addition, as the material for the first partition wall 23B and the second partition wall 24B satisfying the above-mentioned relational expression, a resin material is used that is configured to harden the part irradiated with ultraviolet light and the fluorine component in the resin segregates on the surface of the film . Thereby, it is possible to form the first partition wall 23B and the second partition wall 24B in which the static contact angles of the top portions 23Ba and 24Ba are larger than the static contact angles of the inner wall surfaces 23Bb and 24Bb. In addition, the configuration other than the first partition wall 23B and the second partition wall 24B is the same as the color conversion device 20 of the above-mentioned embodiment.

First, the material used to form the partition wall uniformly contains fluorine in a liquid state. And, in this state, in order to form the partition wall, the material is applied and exposed. In this way, the material in the exposed part starts to polymerize. Then, it is completely hardened by baking. At this time, the fluorine component in the film will segregate upward. As a result, the partition wall is formed in a state where a lot of fluorine is contained on the surface of the partition wall that has been formed.

In addition, the static contact angles of the top 23Ba of the first partition wall 23B and the top 24Ba of the second partition wall 24B can be arbitrarily adjusted by using the above-mentioned materials such as the static contact angle may vary with the film thickness of the partition wall. That is, since the fluorine content of the fluorine-containing resin used varies with the film thickness, the static contact angle will vary.

In addition, different materials may be used to form the first partition wall 23B and the second partition wall 24B to change the static contact angle.

According to the foregoing, in the color conversion device 20B of Modification 2, the wettability of the top 23Ba of the first partition wall 23B becomes low.

Specifically, as shown in FIG. 10A, the ink 40 is applied to the area surrounded by the second partition wall 24B by the inkjet method.

As shown in FIG. 10B, the ink 40 immediately after application exists in such a way as to also cover the top 23Ba of the first partition wall 23B. At this time, as described above, the static contact angle of the top 23Ba of the first partition wall 23B to the ink 40 is greater than the static contact angle of the inner wall surface 23Bb of the first partition wall 23B to the ink 40. Therefore, the ink 40 present on the top 23Ba of the first partition wall 23B slides down along the inner wall surface 23Bb of the first partition wall 23B.

And, finally, as shown in FIG. 10C, the ink 40 will fall in the area surrounded by the first partition wall 23B.

In addition, the wettability of the top 24Ba of the second partition wall 24B is specified by the receding contact angle in addition to the aforementioned static contact angle. The so-called receding contact angle is the state of the liquid-solid interface movement, that is, the contact angle of the dynamic state of the ink interface movement.

At this time, if the receding contact angle is small, the ink that has climbed onto the second partition wall 24B will easily remain wet when it shrinks during drying or curing. Therefore, the ink may remain on the second partition wall 24B. In such a case, the second partition wall 24B is formed such that the contact angle of the second partition wall 24B with respect to the ink receding becomes 15° or more, and preferably 20° or more. As a result, as described below, it is possible to more reliably prevent the ink from remaining wet on the second partition wall 24B. (Comparison of ink wetting caused by different receding contact angles)

The following compares the wettability of ink caused by different receding contact angles, and the results are shown in (Table 1).

(Table 1) shows the static contact angle and receding contact angle of the ink when the material type of the partition wall is changed, and the wettability of the ink on the partition wall. [Table 1] Static contact angle Receding contact angle Wetting of the ink on the partition wall Ink A 64.6° 39.3° No residue wet Ink B 42.6° 18.9° No residue wet Ink C 48.0° 12.2° There is residual moisture Ink D 45.9° 9.6° There is residual moisture

In addition, the receding contact angle is determined by the balance between the material composition of the ink and the surface energy of the material composition of the partition wall.

Specifically, the material composition of the ink is an ink in which a polymer-based luminescent material has been dissolved in an aromatic-based organic solvent. Ink B, Ink C, and Ink D are inks in which quantum dot light-emitting materials have been dispersed in acrylic resin, and are inks produced by different ink manufacturers. In addition, ink B and ink D are indium-phosphorus-based quantum dot materials. Ink C is a cadmium-selenium quantum dot material. In addition, the materials of the partition walls are all acrylic resins containing fluorine compounds.

That is, as shown in (Table 1), if it is ink A and ink B with a receding contact angle of 15° or more, no ink remains wet on the partition wall after the ink shrinks. However, in the case of Ink C and Ink D having a receding contact angle of 15° or less, it can be seen that residual wetting of the ink occurs on the partition wall.

Furthermore, under the above-mentioned combination of materials, as shown in FIG. 10C, the light-emitting layer 21 is not formed on the top 23Ba of the first partition wall 23B. Therefore, the light emitting layer 21 becomes a shape that falls in the first partition wall 23B. Thereby, a color conversion device 20B that can completely prevent the emission of unintended light from outside the light-emitting region of the light-emitting layer 21 is obtained. (Example 3)

Next, the color conversion device 20C of the third modification of the present embodiment will be described using FIGS. 11A to 11C.

FIG. 11A is a plan view of a color conversion device 20C of Modification Example 3. FIG. Fig. 11B is a cross-sectional view taken along line 11B-11B of Fig. 11A. Fig. 11C is a cross-sectional view taken along line 11C-11C of Fig. 11A.

In addition, in the color conversion device 20 of the above-mentioned embodiment, a configuration including one area surrounded by the first partition wall 23 in the area surrounded by the second partition wall 24 has been described as an example.

However, as shown in FIGS. 11A to 11C, the color conversion device 20C of Modification 3 includes two or more regions surrounded by the first partition wall 23C in the region surrounded by the second partition wall 24C. The color conversion device 20C of Modification 3 is different from the color conversion device 20 of the aforementioned embodiment in this point.

Specifically, in Modification 3, a configuration in which four regions surrounded by the first partition wall 23C are included in one region surrounded by the second partition wall 24C is illustrated as an example. At this time, as shown in FIG. 11C, the pixels of each different color are separated by the second partition wall 24C.

According to the color conversion device 20C of Modification 3, ink can be applied to a plurality of pixels on a straight line at a time. Therefore, the uniformity of the film thickness between pixels is improved.

In addition, in general, there is unevenness in the ejected droplet volume between nozzles of an inkjet head due to uneven nozzle processing. However, according to the color conversion device 20C of Modification 3, the light-emitting layer 21 of a plurality of pixels can be formed at a time by using a plurality of nozzles. Therefore, the unevenness of the ejected droplet volume between nozzles is averaged. As a result, the uniformity of the film thickness between the pixels is greatly improved.

In addition, in Modification 3, an example in which the diameter of the region surrounded by the first partition wall 23C is the same as the length in the minor axis direction of the second partition wall 24C is illustrated, but it is not limited to this. For example, as shown in FIG. 12, the area enclosed by the 1st partition wall 23C and the area enclosed by the 2nd partition wall 24C may be formed in the form of, for example, a double circle in a plan view. Specifically, the region surrounded by the second partition wall 24C may be larger in both the major axis direction and the minor axis direction than the region surrounded by the first partition wall 23C. (Other modifications)

Above, the color conversion device and the micro light-emitting diode display panel of the present disclosure have been described based on the embodiments and modifications 1 to 3, but the present disclosure is not limited to the above embodiments and modifications 1 to 3.

For example, in the above-mentioned embodiment and Modifications 1 to 3, the area surrounded by the first partition wall 23, 23B, or 23C that defines the light-emitting area where the light-emitting layer 21 emits light has an example in which the shape of the planar viewing angle is circular It is explained, but it is not limited to this. The first partition wall 23, 23B, or 23C may have a polygonal shape such as a quadrangle, or other shapes such as an oval. Similarly, the shape of the planar viewing angle of the area surrounded by the second partition wall 24 that defines the formation area (ink application area) where the light-emitting layer 21 is formed is not limited to an oblong circle, and other shapes such as a polygonal shape such as a quadrangle may also be used. .

In addition, in the above-mentioned embodiment and modification examples 1 to 3, the blue light-emitting layer 21b does not contain a quantum dot material as an example, but it 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 includes a quantum dot material that emits blue light when irradiated with excitation light such as ultraviolet light.

In addition, for the above-mentioned embodiments and modification examples 1 to 3, various modifications expected by a person having ordinary knowledge in the technical field to which the present invention pertains are implemented, or implemented by arbitrarily combined without departing from the scope of the present disclosure Forms and forms realized by the constituent elements and functions in Modifications 1 to 3 are also included in this disclosure.

In addition, in the above-mentioned embodiments and Modifications 1 to 3, as the luminescent material, a configuration including a quantum dot material has been described as an example, but it is not limited to this, and it may also be a luminescent material including, for example, a perovskite structure. Materials and other luminescent materials.

1: Micro LED display panel 1B, 3B, 7B, 8B, 11B, 11C: line 10: Light-emitting device 11: luminous body 12, 22, 22X: substrate 13: Partition wall 20, 20A, 20B, 20C, 20Z: color conversion device 21, 21Y: light-emitting layer 21X: Functional film 21b: blue light-emitting layer 21g: green light-emitting layer 21r: red light-emitting layer 23, 23B, 23C: the first dividing wall 23a, 23Ba, 24a, 24Ba: top 23Bb, 24Bb: inner wall surface 24, 24B, 24C: second dividing wall 24X, 24Y: dividing wall 25: color filter 25b: Blue color filter 25g: Green color filter 25r: Red color filter 26: luminous body 30: Partition wall material 40, 40Y: ink 40g: green ink 40r: red ink 100: Mask 101: Shading part 102: first opening 103: second opening

1A is a plan view showing an example of the structure of a device used in a display panel with a pixel resolution of 400 ppi.

FIG. 1B is a cross-sectional view showing a situation when ink is discharged to the pixels of the device shown in FIG. 1A.

Fig. 2 is a cross-sectional view of the micro light emitting diode display panel of the embodiment.

Fig. 3A is a plan view of the color conversion device of the embodiment.

3B is a cross-sectional view of the color conversion device in line 3B-3B of FIG. 3A.

Fig. 4 is a cross-sectional view showing another configuration of the color conversion device of the embodiment.

Fig. 5A is a diagram illustrating a substrate preparation step in the method of manufacturing the color conversion device of the embodiment.

Fig. 5B is a diagram illustrating the first partition wall forming step in the method of manufacturing the color conversion device of the embodiment.

Fig. 5C is a diagram illustrating a second partition wall forming step in the method of manufacturing the color conversion device of the embodiment.

Fig. 5D is a diagram illustrating a step of forming a light-emitting layer in the method of manufacturing the color conversion device of the embodiment.

Fig. 6A is a diagram illustrating a partition wall material application step in another method of manufacturing a first partition wall and a second partition wall in the color conversion device of the embodiment.

6B is a diagram illustrating an exposure step in another method of manufacturing the first partition wall and the second partition wall in the color conversion device of the embodiment.

6C is a diagram illustrating an etching step in another method of manufacturing the first partition wall and the second partition wall in the color conversion device of the embodiment.

Fig. 7A is a plan view showing another structure of the color conversion device of the embodiment.

Fig. 7B is a cross-sectional view of the color conversion device in line 7B-7B of Fig. 7A.

Fig. 8A is a plan view of a color conversion device in a comparative example.

Fig. 8B is a cross-sectional view of the color conversion device of the comparative example on the line 8B-8B of Fig. 8A.

9 is a cross-sectional view of the color conversion device of Modification Example 1.

10A is a diagram showing a state where ink is about to be applied in the ink application step of the method of manufacturing the color conversion device of Modification 2. FIG.

10B is a diagram showing a state immediately after ink application in the ink application step of the method of manufacturing the color conversion device of Modification 2. FIG.

10C is a diagram showing the state of the final state in the ink application step of the method of manufacturing the color conversion device of Modification 2. FIG.

FIG. 11A is a plan view of a color conversion device of modification 3. FIG.

Fig. 11B is a cross-sectional view of the color conversion device of Modification 3 along the line 11B-11B of Fig. 11A.

Fig. 11C is a cross-sectional view of the color conversion device of Modification 3 along the line 11C-11C in Fig. 11A.

Fig. 12 is a plan view showing another configuration of the color conversion device of Modification 3.

FIG. 13 is a cross-sectional view of the device disclosed in Patent Document 1. FIG.

3B: Line

20: Color conversion device

21: luminescent layer

21b: blue light-emitting layer

21g: green light-emitting layer

21r: red light-emitting layer

22: substrate

23: The first dividing wall

24: The second dividing wall

Claims (19)

A color conversion device with: Substrate The light-emitting layer is located on the aforementioned substrate and contains a light-emitting material; The first partition wall is in contact with the light-emitting layer and defines a light-emitting area where the light-emitting layer emits light; and The second partition wall is in contact with the aforementioned light-emitting layer and defines the formation area of the aforementioned light-emitting layer, The contact area of the light emitting layer and the first partition wall is larger than the contact area of the light emitting layer and the second partition wall. The color conversion device of claim 1, wherein the area surrounded by the second partition wall includes two or more areas surrounded by the first partition wall. The color conversion device of claim 1 or 2, wherein the first partition wall and the second partition wall are provided on one surface of the substrate, 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 color conversion device of any one of claims 1 to 3, wherein the static contact angle of the top of the first partition wall to the ink forming the color conversion layer is greater than the static contact angle of the top of the second partition wall to the ink small. The color conversion device of claim 4, wherein the static contact angle of the top of the first partition wall and the top of the second partition wall to the ink forming the color conversion layer is 40° or more and 70° or less, and the first partition wall The static contact angle between the side of and the side of the second partition wall to the ink is 5° or more and 40° or less. The color conversion device according to any one of claims 1 to 5, wherein the contact angle of the top of the second partition wall to the ink forming the color conversion layer is 15° or more. The color conversion device according to any one of claims 1 to 6, wherein the aforementioned first distance is 3 μm or more and 7 μm or less, The aforementioned second distance is 6 μm or more and 8 μm or less. The color conversion device of any one of claims 1 to 7, wherein the light-emitting layer is formed by curing the ink containing the light-emitting material, The static contact angle of the top of the first partition wall to the ink is greater than the static contact angle of the side surface of the first partition wall to the ink. The color conversion device of any one of claims 1 to 8, in which the two first partition walls are arranged opposite to each other in a region surrounded by the second partition wall. Such as the color conversion device of claim 9, wherein the shape sandwiched by the two first partition walls is cylindrical. The color conversion device of any one of claims 1 to 9, wherein the first partition wall is a columnar body and is arranged on the side surface of the second partition wall. The color conversion device according to any one of claims 1 to 11, wherein the area surrounded by the aforementioned second partition wall has a flat shape in a plan view. The color conversion device of claim 12, wherein the flat-shaped area is arranged obliquely with respect to the long axis direction of the substrate in a planar viewing angle. The color conversion device according to any one of claims 1 to 13, wherein the first partition wall and the second partition wall comprise a fluorine material. The color conversion device of claim 14, wherein the fluorine material is unevenly included in the first partition wall and the second partition wall. A micro-light-emitting diode display panel having: Such as the color conversion device of any one of claims 1 to 15; and The light emitting device emits light incident on the color conversion device. A manufacturing method of a color conversion device, including: In the first step, a first partition wall is formed on the substrate, and the aforementioned first partition wall is a light-emitting area where the light-emitting layer emits light; In the second step, a second partition wall is formed on the substrate, and the second partition wall defines a formation area for forming the light-emitting layer; and In the third step, an ink containing a light-emitting material is applied to the area surrounded by the second partition wall to form the light-emitting layer, In the first step and the second step, the first partition wall and the second partition wall are formed such that the first distance from the substrate to the top of the first partition wall becomes longer than the distance from the substrate to the The second distance to the top of the second partition wall is shorter. Such as the method of manufacturing a color conversion device of claim 17, wherein in the third step, the ink is applied by the inkjet method, The area surrounded by the aforementioned second partition wall has a flat shape in a plan view, The application direction of the ink is a direction perpendicular to the long axis direction of the area surrounded by the second partition wall. A manufacturing method of a micro-light-emitting diode display panel using the color conversion device manufactured by the color conversion device manufacturing method of claim 17 or 18. The manufacturing method of the aforementioned micro-light-emitting diode display panel includes: In the step of bonding the color conversion device and the light-emitting device, the light-emitting device emits light incident on the color conversion device.

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