WO2020024181A1

WO2020024181A1 - Display device and preparation method therefor

Info

Publication number: WO2020024181A1
Application number: PCT/CN2018/098124
Authority: WO
Inventors: 林茂仲
Original assignee: 深圳市柔宇科技有限公司
Priority date: 2018-08-01
Filing date: 2018-08-01
Publication date: 2020-02-06
Also published as: CN112640117A

Abstract

The present invention relates to the technical field of display, and disclosed thereby is a display device, the display device comprising a first substrate; a color filtering layer that is disposed on the first substrate; and a light-emitting layer, wherein light emitted by the light-emitting layer forms color light after passing through the color filtering layer. The display device further comprises a second substrate and a barrier layer, wherein the second substrate is disposed on a side of the color filtering layer that is far from the first substrate and covers the color filtering layer. Further disclosed by the present invention is a preparation method for a display substrate, comprising the following steps: providing a first substrate; forming a plurality of black matrices that are spaced apart on the first substrate; and forming color filtering units between adjacent black matrices and forming a color filtering layer. The display device and preparation method therefor provided by the present invention may reduce the difficulty of processing large-sized OLED display devices and improve the processing yield of OLED display devices, and are adapted to high resolution and flexible display devices.

Description

Display device and preparation method thereof

Technical field

The present invention relates to the field of display technology, and in particular, to a display device and a manufacturing method thereof.

Background technique

Organic electroluminescence (OLED) display devices are more and more widely used because of their advantages such as high contrast, high brightness, self-luminescence, and low power consumption. OLED display devices usually use red, green and blue sub-pixels to display color images. Usually, the sub-pixels are prepared by using a fine metal mask (FMM), however, the manufacturing process using such a mask is relatively complicated and difficult to manufacture.

Summary of the invention

Embodiments of the present invention provide a display device and a method for manufacturing the same, which can reduce the difficulty of process fabrication. The specific technical solution is described below.

A display device includes a first substrate, a color filter layer disposed on the first substrate, and a light emitting layer, and light emitted from the light emitting layer passes through the color filter layer to form colored light. The display device further includes a second substrate and a barrier layer. The second substrate is disposed on a side of the color filter layer away from the first substrate and covers the color filter layer. On a side of the second substrate away from the color filter layer.

Preferably, the color filter layer includes a plurality of color filter units. The plurality of color filter units include a red filter unit, a green filter unit, and a blue filter unit. The color filter layer further includes a plurality of black matrices, and each black matrix is disposed between two adjacent color filter units.

A method for manufacturing a display device includes the following steps: providing a first substrate; forming a plurality of spaced black matrices on the first substrate; forming a color filter unit between adjacent black matrices to form a color Filter layer.

Preferably, the forming the color filter unit between the adjacent black matrices includes: forming a color photoresist connected to the black matrix on the first substrate, and then modifying the color photoresist Patterning is performed to form the color filter unit. The color filter unit includes a first color filter unit and a second color filter unit with different colors. When the second color filter unit is formed, the first color filter that has been manufactured is formed first. Color photoresist of the unit, and then patterning the color photoresist to form the second color filter unit.

Preferably, when forming the second color filter unit, the color photoresist connected to the first color filter unit is flush with the top surface of the first color filter unit.

Preferably, when forming the second color filter unit, there is a height difference between the color photoresist connected to the first color filter unit and the top surface of the first color filter unit.

Since the display device and the preparation method provided by the present invention do not need to use FMM to prepare sub-pixels, it can reduce the process difficulty and improve the process yield, and can be applied to large-size, high-resolution display devices to meet the needs of flexible lightness .

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings are used to describe various embodiments of the present invention in detail in combination with specific embodiments. It should be understood that the elements illustrated in the drawings do not represent the actual size and proportional relationship, and are merely schematic diagrams for clear description, which should not be understood as limiting the present invention.

1 is a schematic structural diagram of a display device according to a first embodiment of the present invention;

2 is a schematic structural diagram of a display device according to a second embodiment of the present invention;

3 is a flowchart of a method for manufacturing a display device according to a third embodiment of the present invention;

4 is a schematic diagram of a method for forming a black matrix on a first substrate according to a third embodiment of the present invention;

5 is a flowchart of a method for forming a black matrix on a first substrate according to a third embodiment of the present invention;

6 is a schematic diagram of a method for forming a blue filter unit on a first substrate according to a third embodiment of the present invention;

7 is a flowchart of a method for forming a blue filter unit on a first substrate according to a third embodiment of the present invention;

8 is a schematic diagram of a color filter layer on a first substrate provided by a third embodiment of the present invention;

FIG. 9 is a schematic diagram of a method for sequentially forming a second substrate and a barrier layer on a display device according to a third embodiment of the present invention.

detailed description

In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention is further described in detail below with reference to multiple embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

Please refer to FIG. 1, which is an OLED display device 100 according to a first embodiment of the present invention. The display device 100 includes a first substrate 102, a color filter layer 103 disposed on the first substrate 102, and a light emitting layer 107. Light emitted from the light emitting layer 107 passes through the color filter layer 103 to form colored light. The display device 100 further includes a second substrate 104, which is disposed on a side of the color filter layer 103 away from the first substrate 102 and covers the color filter layer 103; a barrier layer 105 is disposed on the second substrate 104 away from One side of the color filter layer 103.

The first substrate 102 is disposed on a rigid substrate 101. The rigid substrate 101 is a transparent glass substrate for supporting the first substrate 102. The color filter layer 103 includes a plurality of adjacent and spaced-apart color filter units, and specifically includes a red filter unit 113a, a green filter unit 113b, and a blue filter unit 113c. Each color filter unit is formed by patterning a photoresist material. The photoresist material forming the color filter unit includes, but is not limited to, resin, which can play a role of color filtering, and also has high flexibility. Preferably, the flexibility of the material of the color filter unit is the same as or close to that of the first substrate 102, so as to better protect the color filter unit.

The color filter layer 103 further includes a black matrix 123a, and the black matrix 123a is disposed between two adjacent color filter units. The black matrix 123a is made of a highly light-shielding material, and may be, for example, a resin material or a metal material doped with a light-shielding substance. The function of the black matrix 123a is to increase the contrast during display and to avoid color mixing. Preferably, the thickness of the black matrix 123a is less than or equal to the thickness of the color filter unit. Preferably, the flexibility of the material of the black matrix 123a is consistent with or close to that of the first substrate 102, so that the color filter layer 103 has flexibility and is suitable for a flexible display screen.

The second substrate 104 serves as a flattening layer of the color filter layer 103, and both of the second substrate 104 and the first substrate 102 are transparent and flexible substrates. The materials of the first substrate 102 and the second substrate 104 include metal substrates, organic polymer substrates, and metal oxide substrates. Organic polymer substrates such as polyethylene terephthalate, polyethersulfone, and polynaphthalene are preferred. Glycol ester, cycloolefin copolymer or polyimide. Preferably, the first substrate 102 and the second substrate 104 are polyimide resin or modified polyimide resin. The blocking layer 105 is disposed on a side of the second substrate 104 away from the color filter layer 103 and is used to block external water and oxygen and protect the internal structure of the display device 100. The barrier layer 105 is an inorganic material selected from an oxide, a nitride, an oxynitride, or a fluoride. Preferably, the barrier layer 105 includes a plurality of silicon dioxide and silicon nitride layers that are alternately stacked.

The display device 100 further includes a thin film transistor array 106 and a packaging layer 108. The thin film transistor array 106 is disposed on a side of the color filter layer 103 away from the rigid substrate 101, and the encapsulation layer 108 covers the light emitting layer 107. The material of the encapsulation layer 108 includes a plurality of organic and inorganic layers that are alternately stacked to isolate external water and oxygen. The light emitted by the light-emitting layer 107 will pass through the thin-film transistor array 106, the color filter layer 103, and the hard substrate 101 in order, and finally be received by the observer, displaying red, green, and blue light, thereby realizing full-color display. The light emitting layer 107 includes a white light emitting layer. It can be understood that, in other embodiments, the light emitting layer 107 may also be a red, green, and blue three-color independent light emitting unit.

Please refer to FIG. 2, which is an OLED display device 200 according to a second embodiment of the present invention. The display device 200 includes a hard substrate 201, a thin film transistor array 206 is disposed on the hard substrate 201, and a light emitting layer 207 is disposed on a side of the thin film transistor array 206 away from the hard substrate 201. The first substrate 202 is disposed on a side of the light emitting layer 207 away from the thin film transistor array 206, and the color filter layer 202 and the second substrate 204 are sequentially stacked on the first substrate 202. In this embodiment, the second substrate 204 is used as a flat layer of the color filter layer 203. The first substrate 202 and the second substrate 204 are both flexible PI substrates. The flexibility of the color filter layer 203 is the same as that of the two substrates. Flexible approach. Specifically, the light emitting layer 207 in this embodiment is a white light emitting layer. The white light emitting layer emits white light after being excited. The white light passes through the color filter layer 202 and displays three colors of red, green, and blue, respectively, and finally the display device 200 is fully colored.

The display device 200 further includes a barrier layer 205 disposed on a side of the second substrate 204 away from the color filter layer 203; and a packaging layer 208 disposed on a side of the barrier layer 205 away from the second substrate 204 to strengthen the display device. The protection of 200 improves the abrasion resistance of the display device 200 and prolongs its service life.

Compared with the combination of the ordinary white-light OLED display device and the filter, the display device in the above embodiment directly prepares the color filter unit on a flexible substrate, which makes the display device display screen provided by the present invention The overall thickness becomes thin. In addition, the color filter layer of the present invention uses a material having flexibility close to that of the first substrate and the second substrate, so that the structure can be applied to a flexible display screen.

Please refer to FIG. 3, which is a flowchart of a method for preparing a display device according to a third embodiment of the present invention, including the following steps: S1, providing a first substrate; S2, forming a plurality of spaced black matrices on the first substrate; S3 , Forming a color filter unit between adjacent black matrices to form a color filter layer.

Specifically, referring to FIG. 3, the first substrate 102 in step S1 in this embodiment is disposed on a rigid substrate 101. The rigid substrate 101 is preferably a transparent glass substrate. The first substrate 102 is a flexible PI (polyimide) layer. Specifically, the transparent PI layer is formed on the glass substrate by spraying, and then the PI layer is thermally baked to harden it. It can be understood that other methods capable of forming the PI layer on the hard substrate 101 are also applicable, for example, slit coating, spin coating, and the like.

Step S2 includes forming a plurality of spaced black matrices on the first substrate. Please refer to FIG. 4 and FIG. 5 together, which are schematic diagrams and flowcharts of a method for forming a black matrix 123a on a first substrate 102 according to a third embodiment of the present invention. In step S301, as shown in 3a in FIG. 4, the first substrate 102 is cleaned. In this embodiment, the PI substrate is cleaned. This cleaning step is a method commonly used by those skilled in the art, and details are not described herein. In step S302, as shown in 3b in FIG. 4, a black photoresist is coated on the PI substrate by a spin coating method to form a black photoresist layer 123. In step S303, the black photoresist layer 123 formed in the previous step is dried in a vacuum, and the black photoresist layer 123 is baked and cooled. Steps S304 and S305, as shown in 3c and 3d in FIG. 4, under the mask of a fixed interval, the black photoresist layer 123 is irradiated with an exposure machine, and then developed with a developing solution to form a black matrix. Patterned black matrix precursor. In step S306, as shown at 3e in FIG. 4, the black matrix precursor is dried to form a black matrix 123a.

Step S3 includes forming a color filter unit between adjacent black matrices, and finally forming a color filter layer. The color filter unit includes a first color filter unit and a second color filter unit of different colors. When forming the second color filter unit, first form a color photoresist connected to the first color filter unit that has been manufactured. Then, the color photoresist is patterned to form a second color filter unit. Specifically, please refer to FIG. 6 and FIG. 7 together, which are a schematic diagram and a flowchart of a method for forming a color filter unit on the first substrate 102 according to the third embodiment of the present invention. In step S311, as shown in 4a in FIG. 6, the PI substrate is cleaned. In step S312, as shown in 4b in FIG. 6, a blue photoresist is coated on the PI substrate by a spin coating method to form a blue photoresist layer 113. In step S313, the blue photoresist layer 113 is dried in a vacuum, and baked and cooled. In steps S314 and S315, as shown in 4c and 4d in FIG. 6, the blue photoresist layer 113 is exposed to ultraviolet light, and then developed using a developing solution to pattern it. In step S316, as shown in 4e in FIG. 6, the blue photoresist layer 113 in the above steps is baked to obtain a blue filter unit 113c.

Next, the same operation is performed to form a green filter unit 113b and a red filter unit 113a on the PI substrate. The invention does not limit the preparation sequence of each color filter unit. In addition, when forming the second color filter unit, the color photoresist connected to the first color filter unit is flush with the top surface of the first color filter unit. That is, the thickness of each color filter unit is the same. In this embodiment, the thicknesses of the blue filter unit, the green filter unit, and the red filter unit are the same. The method for manufacturing a display device provided by the present invention further includes a case where the thicknesses of the color filter units are inconsistent. As shown in FIG. 8, the color filter layer 103 of the display device is formed through the above steps.

In this embodiment, the red filter unit 113a, the green filter unit 113b, the blue filter unit 113c, and the black matrix 123a of the color filter layer are all negative photoresists. The molecular bonds of the negative photoresist will be cross-linked due to the irradiation of light, and it is not easy to be washed away. Therefore, in the yellow light process, the part masked by the photomask, because there is no cross-linking between the molecules, will be dissolved in Wash off the developer. In addition, the color filter unit can also be prepared by other methods, such as spray coating. First, the black matrix 123a is formed on the first substrate 102, and then the red, green, and blue photoresist materials are accurately sprayed by using the inkjet method. In the corresponding color block area, this method omits the process of exposure and development.

In the above-mentioned process of forming a color filter layer, a common metal mask (Common Metal Mask) is used to prepare a color filter unit. First of all, the solution of this solution is simple, and the production difficulty is compared with that of using a fine metal mask to vaporize each sub-pixel Greatly reduced and reduced production costs. Secondly, this solution overcomes the problem that the yield of the display device decreases due to the need for alignment adjustment when the sub-pixels are evaporated using a fine metal mask.

Referring to FIG. 9, after forming the color filter layer 103, in a further embodiment, the method for preparing a display device further includes step S4: forming a second substrate 104, that is, a PI layer, on the color filter layer 103. The second PI layer is used to flatten the color filter layer 103 described above, and the preparation method is the same as that of the first PI layer. It can be sprayed, slit coated, and spin coated, and then baked to harden. Since the flexibility of the first substrate, the second substrate, and the color filter layer is the same, the color filter layer can be applied to a flexible display device.

Please continue to refer to FIG. 9. In a further embodiment, the method for manufacturing a display device further includes step S5: forming a barrier layer 105 on the second substrate 104. The barrier layer 105 is used to block the intrusion of water and oxygen from the outside and protect the internal structure of the display device. The barrier layer 105 is an inorganic material selected from an oxide, a nitride, an oxynitride, or a fluoride, and is formed on the second substrate 104 by a deposition method. In this embodiment, the barrier layer 105 includes a plurality of silicon dioxide and silicon nitride layers that are alternately stacked.

The red, green, and blue light emitting layer layers of the existing organic electroluminescence (OLED) display device need to be deposited by FMM during the preparation process. However, high resolution requires very high alignment accuracy during evaporation, which makes alignment difficult. In addition, when FMM evaporation is used, the probability of foreign objects in the preparation process increases, which reduces the yield of thin film packaging. In the method for manufacturing a display device provided by the embodiment of the present invention, a color filter layer is fabricated on a flexible substrate by means of photolithography or spray coating, thereby avoiding the use of FMM, which can meet the manufacturing process of large-sized display devices and the lightness and thinness of display devices Demand.

The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention shall be included in the protection of the present invention. Within range.

Claims

A display device, comprising:

First substrate

A color filter layer disposed on the first substrate; and

The light emitting layer, the light emitted from the light emitting layer passes through the color filter layer to form colored light.
The display device according to claim 1, wherein the display device further comprises a second substrate and a barrier layer, the second substrate is disposed on a side of the color filter layer away from the first substrate and The color filter layer is covered, and the blocking layer is disposed on a side of the second substrate away from the color filter layer.
The display device according to claim 1, wherein the color filter layer comprises a plurality of color filter units.
The display device according to claim 3, wherein the plurality of color filter units include a red filter unit, a green filter unit, and a blue filter unit.
The display device according to claim 3, wherein the color filter layer further comprises a plurality of black matrices, and each black matrix is disposed between two adjacent color filter units.
The display device according to claim 3, wherein each of the color filter units is patterned by a photoresist material.
The display device according to claim 1, wherein the second substrate is used as a planarization layer of the color filter layer.
The display device according to claim 1, wherein the first substrate and the second substrate are both flexible substrates.
The display device according to claim 1, wherein a material of the color filter layer includes a resin, and a flexibility of the material of the color filter layer is consistent with that of the first substrate.
A method for manufacturing a display device, comprising the following steps:

Providing a first substrate;

Forming a plurality of spaced black matrices on the first substrate;

A color filter unit is formed between the adjacent black matrices to form a color filter layer.
The method for manufacturing a display device according to claim 10, wherein forming the color filter unit between adjacent black matrices comprises: forming a connection to the black matrix on the first substrate Color photoresist, and patterning the color photoresist to form the color filter unit.
The method for manufacturing a display device according to claim 10, wherein the color filter unit comprises a first color filter unit and a second color filter unit having different colors, and the second color filter is formed when the second color filter is formed. When the light unit is formed, a color photoresist connected to the first color filter unit that has been manufactured is formed first, and then the color photoresist is patterned to form the second color filter unit.
The method for manufacturing a display device according to claim 12, wherein, when the second color filter unit is formed, a color photoresist of the first color filter unit and a top surface of the first color filter unit are connected. Flush.
The method for manufacturing a display device according to claim 12, wherein, when the second color filter unit is formed, a color photoresist of the first color filter unit and a top surface of the first color filter unit are connected. There is a height difference.
The method for manufacturing a display device according to claim 11, wherein the color photoresist is a light-transmitting material, and the black matrix is an opaque material.
The method for manufacturing a display device according to claim 11, wherein the color photoresist formed on the first substrate covers the black matrix.
The method for manufacturing a display device according to claim 10, further comprising the step of forming a planarization layer on the color filter layer.
The method for manufacturing a display device according to claim 10, wherein the color filter layer is made of a flexible material.
The method for manufacturing a display device according to claim 10 or 17, wherein the first substrate and the planarization layer are both made of a flexible material.
The method for manufacturing a display device according to claim 10, further comprising the step of forming a barrier layer on the planarization layer.