TW202117411A - Pixel substrate with quantum dots and fabrication method thereof comprising a transparent substrate, a black matrix layer, and a plurality of quantum dot adhesive layers - Google Patents

Abstract

A pixel substrate with quantum dots comprises: a transparent substrate; a black matrix layer formed on the surface of the transparent substrate to define a plurality of pixel spaces; and a plurality of quantum dot adhesive layers individually formed in the pixel spaces. The black matrix layer is made of a negative photoresist material subjected to curing, and forms an included angle less than 90 degrees with the transparent substrate, so that the pixel spaces form an inverted trapezoidal bowl-shaped structure.

Description

Pixel substrate with quantum dots and manufacturing method thereof

The present invention relates to a quantum dot technology, in particular to a pixel substrate with quantum dots and a manufacturing method thereof.

Quantum dots (Quantum Dots), as an applied material for flat panel display technology, have become the display technology for the next generation of display technology. Quantum dots have the following characteristics. The conversion spectrum can be adjusted with the size (by adjusting the size of the nanocrystals of the quantum dots, the size is between 1-20nm), high luminous efficiency, and good luminous stability. In addition, most of the quantum dots are inorganic compounds with stable performance and good durability. This makes quantum dot technology the focus of next-generation display technology.

At present, some manufacturers have developed display technologies such as Quantum Dots Light Emitting Diodes (QD-LEDs) and Quantum Dots Organic Light Emitting Diodes (QD-LEDs). The current development mainly uses the luminescence of light-emitting diodes or organic light-emitting diodes as the light source of quantum dots to convert them to the desired light-emitting spectrum. Regardless of the application method, the manufacturing process of quantum dots is quite different from that of light-emitting diodes or organic light-emitting diodes. Therefore, the production of pixel substrates composed of quantum dots still needs to be compared with the manufacturing process of both. separate.

Therefore, how to simplify the manufacturing process and structure of the pixel substrate formed by quantum dots has become the development direction that the current quantum dot display technology developers want.

To achieve the above objective, the present invention provides a pixel substrate with quantum dots and a manufacturing method thereof, which can achieve the simplest manufacturing process to fabricate a pixel substrate with quantum dots, and facilitate the perfusion of quantum dots, improve the production yield, and further accelerate Quantum dots are used to display the special technical effects of technological progress.

The object of the present invention is to provide a pixel substrate with quantum dots, comprising: a transparent substrate; a black matrix layer formed on the surface of the transparent substrate to define a plurality of pixel spaces; and a plurality of quantum dot adhesive layers are individually formed on In the pixel space; and wherein, the black matrix layer is hardened and made of a negative photoresist material, and forms an included angle less than 90 degrees with the transparent substrate, so that the pixel spaces form an inverted trapezoidal bowl shape structure.

The present invention also provides a method for manufacturing a pixel substrate with quantum dots, including: forming a photoresist layer on the surface of the transparent substrate; exposing the photoresist layer with a mask; and removing the photoresist that has not been exposed The unexposed photoresist layer is made into a black matrix structure of a trapezoidal structure to define a plurality of pixel spaces, and the black matrix structure and the transparent substrate form an included angle less than 90 degrees; curing the black Matrix structure; and these pixel spaces are individually correspondingly perfused with a quantum dot glue layer of corresponding pixel material.

In order to make the above and other objects, features, and advantages of the present invention more comprehensible, several preferred embodiments are listed below in conjunction with the accompanying drawings, which are described in detail as follows (implementations).

2‧‧‧Part

10‧‧‧Pixel substrate with quantum dots

11‧‧‧Transparent substrate

12‧‧‧Photoresist layer

12-1‧‧‧Black matrix layer

20‧‧‧Light-emitting layer

30-1, 30-2, 30-3‧‧‧Quantum dot adhesive layer

40‧‧‧Mask

80‧‧‧UV

90‧‧‧Light

91‧‧‧Target Light

Figure 1 is a flow chart of a method for manufacturing a pixel substrate with quantum dots disclosed in the present invention.

Figures 2A-2E are a flow chart for making a cross-sectional view of part 2 of Figure 3B.

FIG. 3A illustrates a schematic diagram of the pixel substrate 10 with quantum dots and the corresponding light-emitting substrate 20 of the present invention.

FIG. 3B is an enlarged schematic diagram of the pixel substrate 10 with quantum dots and the corresponding part 2 of the present invention.

FIG. 3C is a schematic cross-sectional view of the part 2 of the pixel substrate 10 with quantum dots along the A-A section line of the present invention.

According to an embodiment of the present invention, the present invention uses an exposure and development process to fabricate a pixel substrate with quantum dots, thereby fabricating a high-precision black matrix layer, so that the quantum dots can be accurately poured into the pixel space defined by the black matrix layer Among them, the pixel substrate with quantum dots required by the next-generation display technology with simple manufacturing process and high resolution can be used as a quantum dot display.

Please refer to Fig. 1, the flow chart of the manufacturing method of a pixel substrate with quantum dots disclosed in the present invention. Please also refer to Figs. 2A-2E (the manufacturing process of the cross-sectional view of part 2 of Fig. 3B), including:

Step S101: forming a photoresist layer on the surface of the transparent substrate; for example, a spraying method is used to gradually form a photoresist with a thickness of 1.5um to 20um; alternatively, a photoresist with a thickness of 15um to 20um is formed. Since this photoresist layer will be made as a permanent material layer in the future, a negative photoresist is used to make it. In addition, the photoresist layer will be made into a black matrix structure. Therefore, a negative photoresist material doped with black pigments can be used. As shown in FIGS. 2A and 2B, in the area of the enlarged part 2, a photoresist layer 12 with a film thickness between 1.5um and 20um is formed on the transparent substrate 11 by spraying.

Step S102: Expose the photoresist layer with a photomask; this photomask is a photomask pattern corresponding to the black matrix structure, and can be exposed to ultraviolet light. As shown in FIG. 2C, the photoresist layer 12 can be exposed by the photomask 40 under the ultraviolet light 80 exposure.

Step S103: Remove the unexposed photoresist layer, and make the unexposed photoresist layer into a black matrix structure of a trapezoidal structure to define a plurality of pixel spaces, and the black matrix structure and the transparent substrate An included angle less than 90 degrees is formed; since the selected photoresist material is a negative photoresist, the unexposed part can be removed by the developer. The exposed part will remain as the black matrix structure reserved by the present invention. In addition, since the black matrix structure to be formed and the part in contact with the transparent substrate form an angle less than 90 degrees, the black matrix layer 12-1 itself forms a positive trapezoidal structure, and an appropriate developer and developer can be selected during the development process. Development time to make this trapezoidal structure. The angle of the included angle is between 45 and 90 degrees, or the angle of the included angle is between 60 and 85 degrees. Please refer to Figure 2D, the exposed part constitutes the black matrix layer 12-1.

Step S104: curing the black matrix structure; for example, further curing the black matrix structure into a permanent material layer through thermal curing or light curing.

Step S105: Pouring a quantum dot adhesive layer of corresponding pixel materials into the pixel spaces individually. For example, inkjet printing can be used to accurately convert the same light source into different colors of quantum dots and inkjet coating them in the corresponding pixel space. Wherein, the thickness of the quantum dot adhesive layer is smaller than the thickness of the black matrix layer, and is between 1 um and 15 um, or between 1 um and 9 um, or between 1 um and 5 um. Please refer to Figure 2E, the quantum dot adhesive layers 30-1, 30-2, and 30-3 are respectively formed independently in the pixel space formed by the black matrix layer 12-1, and can be individually adjusted according to different light conversion efficiencies. Adjusting the thickness of the quantum dot adhesive layer 30-1, 30-2, 30-3 can be achieved by controlling the length of time for inkjet coating. The thickness of the quantum dot adhesive layer with higher light conversion efficiency, It is smaller than the thickness of the quantum dot adhesive layer with lower light conversion efficiency. This technical feature can solve the problem of different conversion rates of different quantum dot formulations, so that the quantum dots of different colors can achieve the same Luminance, and then achieve the special technical effect of solving the color shift problem caused by the different conversion efficiency of quantum dots. For example, the light conversion efficiency of the quantum dot adhesive in the quantum dot adhesive layer 30-1 is 95%, and the light conversion efficiency of the quantum dot adhesive in the quantum dot adhesive layer 30-2 is 85%, and the quantum dot adhesive layer 30 The light conversion efficiency of the quantum dot adhesive in -3 is 70%. In the present invention, the thickness of the quantum dot adhesive layer 30-1, 30-2, 30-3 corresponds to the basic thickness/95%, basic thickness/85%, Basic thickness/70%. In this way, a situation where the thicknesses of the quantum dot adhesive layers 30-1, 30-2, and 30-3 are not the same as shown in FIG. 2E is formed. Of course, if the conversion efficiencies of the quantum dots of different colors, such as red, blue, and green, are the same, the thickness of the quantum dots corresponding to the three can be the same. Wherein, the basic thickness of the quantum dot adhesive layer is also smaller than the thickness of the black matrix layer, and the thickness of the quantum dot adhesive layer after conversion efficiency conversion must also be smaller than the thickness of the black matrix layer.

Wherein, the transparent substrate 11 may be a PET substrate (Polyethylene terephthalate, PET for short), a COP substrate, a PC substrate, a CPI substrate, a glass substrate, and a polyvinyl butyral resin (Polyvinyl Butyral Resin for short). PVB) substrate etc. The light transmittance of the transparent substrate 10 in the visible light waveband is greater than 80%.

The photoresist in the present invention uses a negative photoresist, but preferably, the photoresist layer of the present invention uses a high-resolution negative photoresist. The material of the photoresist layer is mainly composed of polymer resin (Resin), photo initiator (Photo initiator), monomer (Monomer), solvent (Solvent), and additives (Additives).

Among the materials of the photoresist layer, the function of polymer resin (Resin) lies in adhesion, developability, pigment dispersibility, fluidity, heat resistance, chemical resistance, and resolution; The function of the initiator (Photo initiator) lies in the photosensitivity and resolution; the function of the monomer (Monomer) lies in the adhesion, development and resolution; the function of the solvent (Solvent) lies in the viscosity and coating properties; the function of the additive (Additives) The function is coating, leveling and foaming.

The polymer resin (Resin) can be a polymer or copolymer containing carboxylic acid group (COOH), such as acrylic resin, acrylic-epoxy resin, acrylic_melamine ( Melamine resin, acrylic-styrene (Styrene) resin, phenol-phenol (Phenolic Aldehyde) resin and other resins, or any combination of the above resins, but not limited to this. The weight percentage of the resin in the photoresist can range from 0.1% to 99%.

Monomers can be divided into water-insoluble monomers and water-soluble monomers. Among them, water-insoluble monomers can be penerythritol triacrylate, trimethyl ether propane triacrylate, and trimethyl ether propane. Trimethacrylate, tris, diethanol isocyanate triacrylate, di, trimethanol propane tetraacrylate, diisopentaerythritol pentaacrylate, pentaacrylate, isopentaerythritol tetraacetate; dihexanetetraacetate Alcohol, diisopentaerythritol hexaacetate, or multifunctional monomer, dendrimer/multiplex acrylate oligomer, polyether acrylate, urethane. Water-soluble monomers can be monomers of Ethoxylated (polyoxyethylene) (EO for short) base and Propoxylated (polyoxypropylene) (PO for short); for example: two-(two-) Oxyethylene oxyethylene) vinyl acrylic acid unitary, pentadecoxyethylene trimethanol propane triacrylate, triacontanoxyethylene di, two-bis-p-phenol methane diacrylate, thirty oxyethylene di, two-pair Phenol methane dimethacrylic acid unitary, eicosoxyethylene trimethanol propane triacrylate, pentaoxyethylene trimethanol propane triacrylate, methyloxy 550 oxyethylene monomethacrylate, two hundred oxygen Ethylene diacrylate, four hundred oxyethylene diacrylate unitary, four hundred oxyethylene dimethacrylate, six hundred oxyethylene diacrylate, six hundred oxyethylene dimethacrylate, polyoxypropylene monomethacrylate . Of course, two or more monomers can also be added and mixed to form a co-monomer. The weight percentage of monomer or comonomer in the photoresist can range from 0.1% to 99%.

The photo initiator can be selected from acetophenone, benzophenone, bis_imidazole, benzoin, and benzidine. Benzil, α-amino ketone, Acyl phosphine oxide, or benzoyl formate compound can be any combination of the above photoinitiators, but Not limited to this. The weight percentage of the photoinitiator in the photoresist can range from 0.1 to 10%.

The solvent (Solvent) can be ethylene glycol monopropylether, di-ethylene glycol dimethylether, tetrahydrofuran, ethylene glycol monomethyl ether, and ethylene glycol monomethyl ether. ethyleneglycol monoethyl ether), di-ethylene glycol mono-methylether, di-ethylene glycol mono-ethyl ether, di-ethylene glycol mono-butyl ether (di-ethylene glycol mono-methylether) butyl ether), propylene glycol mono-methyl ether acetate, propylene glycol mono-ethyl ether acetate, propylene glycol mono-propyl ether acetate, 3- Ethoxy propionate (ethyl3_ethoxy propionate), etc., or any combination of the above solvents, but not limited thereto. The weight percentage of the solvent in the photoresist can range from 0.1% to 99%.

Additives are generally pigment dispersants, which are necessary ingredients for photoresists containing pigments. They are generally non-ionic interfacial active agents, such as Solsperse 39000 and Solsperse 21000. The weight percentage of this dispersant in the photoresist can range from up to 0.1 to 5%.

When performing exposure in step S102 of the present invention, it further includes: (1) substrate cleaning (Substrate Clean); (2) Coating; (3) Pre-baking; (4) Exposure; (5) Development (Developing) and other processing steps.

Next, please refer to Figure 3A, which illustrates a schematic diagram of the pixel substrate 10 with quantum dots of the present invention and its corresponding light-emitting substrate 20; Figure 3B is a schematic diagram of the pixel substrate 10 with quantum dots of the present invention and its corresponding An enlarged schematic view of part 2 of; Figure 3C is a schematic cross-sectional view of part 2 of the pixel substrate 10 with quantum dots of the present invention along the AA section line.

Figures 3A-3C disclose the pixel substrate 10 with quantum dots of the present invention, which includes: a transparent substrate 11, a black matrix layer 12-1 and a plurality of quantum dot adhesive layers 30-1, 30-2, 30-3 . Among them, the black matrix layer 12-1 is formed on the surface of the transparent substrate 10 to define a plurality of pixel spaces; a plurality of quantum dot adhesive layers 30-1, 30-2, 30-3 are individually formed in the pixel spaces, and can Have the same thickness or different thicknesses. Wherein, the black matrix layer 12-1 is made by hardening a negative photoresist material, and the part in contact with the transparent substrate 10 forms an included angle of less than 90 degrees (the black matrix layer 12-1 itself is a positive ladder structure) , And the pixel spaces form an inverted trapezoidal bowl-shaped structure, as shown in Figure 3C.

In Fig. 3A, this is an example in which the light-emitting layer 20 is used. The light emitting layer 20 may be an LED light emitting layer or an OLED light emitting layer. The light 90 emitted by the control light-emitting layer 20 can be converted into the target light 91 after being converted by the pixel substrate 10 with quantum dots.

Wherein, the thickness of the black matrix layer 12-1 is between 1.5um and 40um; according to another embodiment of the present invention, the thickness of the black matrix layer is between 3um and 40um; according to another embodiment of the present invention, In other words, the thickness of the black matrix layer is between 5um and 20um; in another embodiment of the present invention, the thickness of the black matrix layer is between 5um and 30um. Wherein, the angle of the included angle is between 45 to 90 degrees; in another embodiment of the present invention, the angle of the included angle is between 60 to 85 degrees. Wherein, the thickness of the plurality of quantum dot adhesive layers 30-1, 30-2, 30-3 is less than the thickness of the black matrix layer 12-1, and is between Between 1um and 15um, or between 1um-9um.

Although the technical content of the present invention has been disclosed in the preferred embodiment as above, it is not intended to limit the present invention. Anyone who is familiar with this technique and makes some changes and modifications without departing from the spirit of the present invention should be covered by the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of the attached patent application.

2‧‧‧Part

11‧‧‧Transparent substrate

12-1‧‧‧Black matrix layer

30-1, 30-2, 30-3‧‧‧Quantum dot adhesive layer

Claims (22)

A pixel substrate with quantum dots, including: A transparent substrate; A black matrix layer is formed on the surface of the transparent substrate and defines a plurality of pixel spaces; A plurality of quantum dot adhesive layers are individually formed in the pixel space; and Wherein, the black matrix layer is hardened and made of negative photoresist material, and the part in contact with the transparent substrate forms an included angle less than 90 degrees, so that the pixel spaces form an inverted trapezoid bowl-shaped structure. The pixel substrate with quantum dots according to claim 1, wherein the thickness of the black matrix layer is between 3um and 40um. The pixel substrate with quantum dots according to claim 1, wherein the thickness of the black matrix layer is between 3um and 30um. The pixel substrate with quantum dots according to claim 1, wherein the thickness of the black matrix layer is between 3um and 20um. The pixel substrate with quantum dots according to claim 1, wherein the angle of the included angle is between 45 and 90 degrees. The pixel substrate with quantum dots according to claim 1, wherein the angle of the included angle is between 60 and 85 degrees. The pixel substrate with quantum dots according to claim 2 or 3, wherein the thickness of the plurality of quantum dot adhesive layers is smaller than that of the black matrix layer and is between 1um and 15um. The book element substrate with quantum dots according to claim 2 or 3, wherein the thickness of the plurality of quantum dot adhesive layers is smaller than that of the black matrix layer and is between 1um and 9um. The pixel substrate with quantum dots according to claim 1, wherein the quantum dot adhesive layers include a plurality of quantum dot adhesives with different light conversion rates, and the quantum dots of the quantum dot adhesives with the same light conversion rate The thickness of the adhesive layer is the same, and the thickness of the quantum dot adhesive layers of quantum dot adhesives with different light conversion efficiencies is different. The pixel substrate with quantum dots according to claim 9, wherein among the quantum dot adhesive layers, the thickness of the quantum dot adhesive layer with higher light conversion efficiency is smaller than that of the quantum dot adhesive layer with lower light conversion efficiency The thickness of the layer. A method for manufacturing a pixel substrate with quantum dots includes: Forming a photoresist layer on the surface of the transparent substrate; Expose the photoresist layer with a photomask; The unexposed photoresist layer is removed, and the unexposed photoresist layer is made into a black matrix structure of a trapezoidal structure to define a plurality of pixel spaces, and the black matrix structure and the transparent substrate form a smaller An included angle of 90 degrees; Curing the black matrix structure; and The pixel spaces are individually correspondingly perfused with a quantum dot glue layer of the corresponding pixel material. The method for manufacturing a pixel substrate with quantum dots according to claim 11, wherein the step of forming the photoresist layer on the surface of the transparent substrate is by spraying. According to claim 11, the method for manufacturing a pixel substrate with quantum dots, wherein the step of injecting the quantum dot adhesive layer of the corresponding pixel material into the pixel spaces corresponds to an inkjet coating method. The method for manufacturing a pixel substrate with quantum dots according to claim 11, wherein the thickness of the black matrix layer is between 3 um and 40 um. The method for manufacturing a pixel substrate with quantum dots according to claim 11, wherein the thickness of the black matrix layer is between 3 um and 30 um. The method for manufacturing a pixel substrate with quantum dots according to claim 11, wherein the thickness of the black matrix layer is between 3um and 20um. The method for manufacturing a pixel substrate with quantum dots according to claim 11, wherein the angle of the included angle is between 45 and 90 degrees. The method for manufacturing a pixel substrate with quantum dots according to claim 11, wherein the angle of the included angle is between 60 and 85 degrees. The method for manufacturing a pixel substrate with quantum dots according to claim 13, 14 or 15, wherein the thickness of the plurality of quantum dot adhesive layers is smaller than that of the black matrix layer and is between 1um and 15um. The method for manufacturing a pixel substrate with quantum dots according to claim 13, 14 or 15, wherein the thickness of the plurality of quantum dot adhesive layers is smaller than that of the black matrix layer and is between 1 um and 9 um. The method for manufacturing a pixel substrate with quantum dots according to claim 11, wherein the quantum dot adhesive layers include a plurality of quantum dots with different light conversion rates, and the quantum dots with the same light conversion rate The thickness of the quantum dot adhesive layers is the same, and the thickness of the quantum dot adhesive layers is different for quantum dot adhesives with different light conversion efficiencies. The method for manufacturing a pixel substrate with quantum dots according to claim 21, wherein among the quantum dot adhesive layers, the thickness of the quantum dot adhesive layer with higher light conversion efficiency is smaller than the thickness of the quantum dot adhesive layer with lower light conversion efficiency The thickness of the quantum dot adhesive layer.

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