CN114784063A

CN114784063A - Display panel and preparation method thereof

Info

Publication number: CN114784063A
Application number: CN202210373411.XA
Authority: CN
Inventors: 李才文; 覃事建
Original assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2022-04-11
Filing date: 2022-04-11
Publication date: 2022-07-22
Also published as: CN115701252A

Abstract

The application discloses a preparation method of a display panel, which comprises the following steps: providing a glass substrate; preparing an OLED array layer on the glass substrate; preparing a passivation layer and a flat layer on the OLED array layer, and etching through holes on the passivation layer and the flat layer; wherein, in the step of etching the through holes on the passivation layer and the flat layer: arranging a light resistance layer on one side of the glass substrate far away from the OLED array layer; carrying out hydrofluoric acid spraying treatment to form a through hole on the passivation layer; and laser stripping the photoresist layer. The technical effect of the application is that the glass substrate is protected from corrosion when the passivation layer is etched by hydrofluoric acid.

Description

Display panel and preparation method thereof

Technical Field

The application relates to the field of display, in particular to a display panel and a preparation method thereof.

Background

In the existing flexible device TFT manufacturing process, in order to reduce one illumination, hydrofluoric acid HF is selected to etch the passivation layer, but at the same time, the back surface of the glass substrate is also corroded when passing HF acid, and is in a water drop shape in a macroscopic state, so that roller printing white dirt exists, and the back surface of the glass substrate is in a sand-gravel shape in a microscopic state.

Disclosure of Invention

The application aims to provide a display panel and a preparation method thereof, which can solve the technical problems of serious corrosion, roller printing and the like of a glass substrate in the existing manufacturing process of etching a passivation layer by hydrofluoric acid of the display panel.

In order to achieve the above object, the present application provides a method for manufacturing a display panel, including the steps of: providing a glass substrate; preparing an OLED array layer on the glass substrate; preparing a passivation layer and a flat layer on the OLED array layer, and etching through holes on the passivation layer and the flat layer; wherein, in the step of etching the through holes on the passivation layer and the flat layer: arranging a light resistance layer on one side of the glass substrate far away from the OLED array layer; carrying out hydrofluoric acid spraying treatment to form a through hole on the passivation layer; and laser stripping the photoresist layer.

Further, the step of preparing the OLED array layer on the glass substrate includes: and sequentially preparing a shading layer, a buffer layer, an active layer, a grid insulating layer, a grid layer, a dielectric layer and a source drain electrode layer on the glass substrate.

Further, the step of preparing a passivation layer and a planarization layer on the OLED array layer includes: depositing a layer of insulating material on the upper surfaces of the source drain electrode layer and the dielectric layer to serve as a passivation layer; coating a layer of inorganic material on the upper surface of the passivation layer to form a flat layer; and after exposure, development, baking and etching, forming a first through hole on the flat layer, wherein the first through hole is arranged opposite to the drain electrode in the source/drain electrode layer.

Further, the step of disposing a photoresist layer on a side of the glass substrate away from the OLED array layer includes: and spraying a light resistance material on one side of the glass substrate far away from the OLED array layer, and baking and curing.

Further, in the step of performing hydrofluoric acid spraying treatment: and carrying out hydrofluoric acid spraying treatment at least twice, and forming a second through hole at the passivation layer below the first through hole, wherein the second through hole is mutually communicated with the first through hole to form the through hole.

Further, after the hydrofluoric acid spraying step, air drying treatment is performed.

Further, when the photoresist material is sprayed, a roller type roller is adopted to roll on the bottom surface of the glass substrate, so that the photoresist material is uniformly sprayed.

Further, in the step of performing the baking curing treatment, a heating wire or an extreme ultraviolet curing treatment is used.

In order to achieve the above object, the present application further provides a display panel, which is prepared by the preparation method of the display panel as described above.

Further, the display panel includes: a glass substrate; the OLED array layer is arranged on the surface of one side of the glass substrate; the passivation layer is arranged on the surface of one side, away from the glass substrate, of the OLED array layer, and a second through hole formed by etching through hydrofluoric acid is formed in the passivation layer; the flat layer is arranged on the surface of one side, away from the OLED array layer, of the passivation layer, a first through hole is formed in the flat layer, the first through hole is communicated with the second through hole, and the formed through hole is opposite to the drain electrode on the OLED array layer.

The utility model provides a technical effect lies in, at the lower surface spraying one deck light resistance layer of glass substrate, when carrying out hydrofluoric acid spray etching to the passivation layer, the light resistance layer can play the protection glass substrate's effect prevents that its surface from leaving the gyro wheel seal, avoids being corroded by hydrofluoric acid, just can avoid glass substrate is the white filth of drop form and gyro wheel seal form under the macroscopic state, presents phenomenons such as grit form under the microcosmic state, can reduce to peel off the degree of difficulty when actual production, prevents that OLED array layer from receiving to drag and then causing display surface Peeling, lighting a lamp back picture to appear black spot, thin black line scheduling problem, improves display panel's display effect, improves display device's yield.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a flowchart of a method for manufacturing a display panel according to an embodiment of the present disclosure;

FIG. 2 is a schematic structural diagram of a light-shielding layer provided in an embodiment of the present application after being prepared;

FIG. 3 is a schematic structural diagram of a buffer layer prepared according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram after an active layer is prepared according to an embodiment of the present application;

FIG. 5 is a schematic diagram illustrating a structure of a gate insulating layer after being formed according to an embodiment of the present disclosure;

fig. 6 is a schematic structural diagram after a gate layer is fabricated according to an embodiment of the present disclosure;

FIG. 7 is a schematic diagram illustrating a structure of a dielectric layer after being formed according to an embodiment of the present application;

fig. 8 is a schematic structural diagram after a source/drain layer is prepared according to the embodiment of the present application;

fig. 9 is a schematic structural diagram after a first through hole is prepared according to an embodiment of the present application;

fig. 10 is a flowchart of preparing a second through hole according to an embodiment of the present application;

FIG. 11 is a schematic diagram illustrating a structure of a photoresist prepared according to an embodiment of the present application;

FIG. 12 is a top view of the interior of a bake chamber provided by an embodiment of the present application;

FIG. 13 is a schematic structural view of hydrofluoric acid treated provided in accordance with an embodiment of the present application;

FIG. 14 is a schematic diagram illustrating a structure of a laser-stripped photoresist according to an embodiment of the present application;

description of the reference numerals:

100. a glass substrate; 200. an OLED array layer; 300. a passivation layer; 400. a planarization layer;

201. a light-shielding layer; 202. a buffer layer; 203. an active layer; 204. a gate insulating layer; 205. a gate layer; 206. a dielectric layer; 207. a source electrode; 208. a drain electrode;

2061. a dielectric layer via;

301. a second through hole; 401. a first through hole;

10. a photoresist layer; 20. a nozzle; 30. a baking chamber; 31. a baking device.

Detailed Description

The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application. Furthermore, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present application, are given by way of illustration and explanation only, and are not intended to limit the present application. In the present application, unless indicated to the contrary, the use of the directional terms "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, and more particularly to the orientation of the figures of the drawings; while "inner" and "outer" are with respect to the outline of the device.

The embodiment of the application provides a display panel and a preparation method thereof. The following are detailed below. It should be noted that the following description of the embodiments is not intended to limit the preferred order of the embodiments.

As shown in fig. 1, the present embodiment provides a method for manufacturing a display panel, including steps S1 to S3.

S1 provides a glass substrate 100, where the glass substrate 100 serves as a substrate and a support, and the glass substrate 100 is cleaned to reduce the influence of particles on the subsequent processes.

S2, preparing an OLED array layer 200 on the glass substrate 100, as shown in fig. 2 to 8, sequentially preparing a light shielding layer 201, a buffer layer 202, an active layer 203, a gate insulating layer 204, a gate layer 205, a dielectric layer 206, a source 207, and a drain 208 to obtain the OLED array layer 200, where the OLED array layer 200 is a circuit control switch of the display panel.

The preparation steps of the OLED array layer 200 are as follows:

a layer of metal material is prevented from being deposited on the upper surface of the glass substrate 100 by adopting a physical deposition coating, the metal material is a single-layer metal material or a multi-layer combined material or an alloy material such as copper (Cu), molybdenum (Mo), titanium (Ti), aluminum (Al), and the like, and a light shielding layer 201 (see fig. 2) is formed after patterning through operations such as photoresist coating, exposure, development, etching, film stripping, and the like, and the light shielding layer 201 plays a role in shielding incident light.

An inorganic material is deposited on the upper surfaces of the glass substrate 100 and the light-shielding layer 201 by a chemical deposition coating method, the inorganic material may be a single layer or a laminated structure of silicon nitride (SiN) or silicon oxide (SiO), a buffer layer 202 (see fig. 3) is formed, and the buffer layer 202 has an effect of isolating external water and oxygen.

A layer of semiconductor material is deposited by physical deposition of a coating on the upper surface of the buffer layer 202, for example: indium Gallium Zinc Oxide (IGZO), Indium Gallium Tin Oxide (IGTO), etc., and then patterned by photoresist coating, exposure, development, etching, film stripping, etc., to form the active layer 203 (see fig. 4). The active layer 203 is formed of a single layer or a stacked structure of these semiconductor materials or an alloy material.

A layer of inorganic material, which is typically a single layer or a stacked structure of silicon nitride (SiN) or silicon oxide (SiO), is deposited on the upper surface of the active layer 203 by using an electroless deposition coating, so as to form the gate insulating layer 204 (see fig. 5).

A layer of metal material, which is a single-layer metal material or a multi-layer combined material or an alloy material, such as copper (Cu), molybdenum (Mo), titanium (Ti), aluminum (Al), etc., is deposited on the upper surface of the gate insulating layer 204 by means of physical deposition coating, and then the gate layer 205 is formed by operations such as photoresist coating, exposure, development, etching, stripping, etc. (see fig. 6).

It is to be noted in particular that: the etching step is to etch a pattern layer of the gate layer 205 by a wet etching process, and then etch a pattern of the gate insulating layer 204 by a dry etching process, so that the gate layer 205, the gate insulating layer 204 and the active layer 203 are arranged oppositely, and He gas is used for inducing conductization, so that the part of the active layer 203 covered by the gate layer 205 and the gate insulating layer 204 still retains the semiconductor performance, and the uncovered part is conductized and has the conductor performance.

Depositing a layer of inorganic material on the upper surfaces of the gate electrode layer 205, the gate insulating layer 204, the active layer 203 and the buffer layer 202 by chemical deposition coating, wherein the inorganic material is a single-layer or stacked structure of silicon nitride (SiN) or silicon oxide (SiO), and performing operations such as photoresist coating, exposure, development, etching, film stripping, and the like to form a dielectric layer 206 after patterning, in the etching process, the mask plate etches the dielectric layer 206 by dry etching, a dielectric layer through hole 2061 (see fig. 7) is formed after etching, and the dielectric layer through hole 2061 is used as a connecting channel between a subsequent source and drain electrode and the active layer 203.

A layer of metal material is deposited on the upper surface of the dielectric layer 206 by means of physical deposition coating, the metal material is a single-layer metal material or a multi-layer composite material or an alloy material such as copper (Cu), molybdenum (Mo), titanium (Ti), aluminum (Al), etc., and then the source electrode 207 and the drain electrode 208 are formed after patterning through operations such as photoresist coating, exposure, development, etching, stripping, etc. (see fig. 8).

S3, preparing a passivation layer 300 and a flat layer 400 on the OLED array layer 200, and etching through holes on the passivation layer 300 and the flat layer 400, which will be described in detail below with reference to fig. 9 to 14.

A layer of insulating material, which is silicon nitride (SiN) and/or silicon oxide (SiO), is deposited on the upper surfaces of the source electrode 207, the drain electrode 208 and the dielectric layer 206 by chemical deposition, so as to form a passivation layer 300. Then, a layer of inorganic material is coated on the upper surface of the passivation layer 300 by using a coater to form a flat layer 400, and then, the operations of exposure, development and baking are respectively performed on the flat layer 400, and after ashing, a first through hole 401 (see fig. 9) is formed on the flat layer 400 to expose a portion of the passivation layer 300, and the first through hole 401 is disposed opposite to the drain electrode 208.

In the conventional flexible device TFT, in order to reduce one-line light exposure, hydrofluoric acid (HP) is selected to etch the passivation layer, but at the same time, the back surface of the glass substrate is also corroded by hydrofluoric acid, resulting in white stains in a droplet shape and a roller mark shape in a macroscopic state, and gritty stains in a microscopic state. The biggest influence of corrosion of the glass substrate is that laser stripping is difficult in practical production, an OLED device layer is easy to cause a display panel to fall off after being pulled, and black spots, thin black lines and other phenomena appear on a picture after lighting.

As shown in fig. 10 to fig. 14, in order to solve the above problem, in this embodiment, a photoresist layer is added on the back surface of the glass substrate 100, that is, on the side away from the OLED array layer 200, so that the glass substrate 100 can be protected from corrosion when the whole device is etched by hydrofluoric acid. The specific process includes steps S31-S36, which will be described in detail below.

S31 photo resist spraying, specifically, disposing a photo resist layer 10 on a side of the glass substrate 100 away from the OLED array layer 200, i.e. spraying a layer of photo resist material on the back surface of the glass substrate 100 through a nozzle 20 (see fig. 11), where the nozzle 20 is disposed below the glass substrate 100 and sprays the photo resist material upwards, the material of the photo resist material includes resin, photosensitizer, solvent, and the like, and the nozzle 20 is located right below the glass substrate 100 to protect the lower surface of the glass substrate 100, and the thickness of the sprayed photo resist material is about 1 μm. In the spraying process, a roller is used to ensure that the photoresist is uniformly sprayed on the lower surface of the glass substrate 100.

And S32, performing baking and curing treatment, namely, transmitting the whole device sprayed with the photoresist material into the baking chamber 30 for baking and curing treatment to form the photoresist layer 10, wherein the baked and cured photoresist layer 10 has better adhesive force with the glass substrate 100. The top of the bake chamber 30 is provided with a bake device 31, the bake device 31 is typically a heating wire or an extreme ultraviolet device (EUV) (see fig. 12), the heating wire or EUV being uniformly distributed to ensure that the device is heated uniformly when baked, and the heating wire typically heats the room temperature inside the bake chamber 30 to 100 ℃ when baked.

S33, performing a first hydrofluoric acid spraying process, transferring the entire device after baking and curing to a liquid chemical tank in a hydrofluoric acid processing chamber, and starting the hydrofluoric acid spraying process, wherein during the process, the passivation layer 300 exposed by the first through hole 401 on the planarization layer 400 is corroded by the hydrofluoric acid, and during the process, the photoresist layer 10 on the lower surface of the glass substrate 100 is also partially corroded but is not completely corroded, and the glass substrate 100 protected by the passivation layer is not exposed, so that the glass substrate 100 is not corroded and is well protected during the hydrofluoric acid spraying process.

S34 performs a second hydrofluoric acid spraying process, which is the same as the first hydrofluoric acid spraying process, and the two or even multiple hydrofluoric acid spraying processes are performed because the width of the existing hydrofluoric acid spraying chamber is not sufficient and the etching is difficult to complete in one operation, so that the hydrofluoric acid spraying chamber needs to be sprayed in segments, and the multiple spraying processes are also performed to improve the etching uniformity of the hydrofluoric acid on the passivation layer 300, and the multiple etching is performed until the drain electrode 208 under the passivation layer 300 is exposed, so as to form a second through hole 301 (see fig. 13), where the second through hole 301 is communicated with the first through hole 401, and the formed through hole is used as an electrical connection channel between a subsequent anode layer and the drain electrode 208.

And S35, carrying out air drying treatment, conveying the etched whole device into an air drying chamber for air drying treatment, and ensuring that the whole device is dried and then carrying out the next process.

S36 laser lift off the photoresist layer 10, specifically, the photoresist layer 10 is separated from the glass substrate 100 by laser lift off (see fig. 14), in this process, the process difficulty is not increased, and the existing laser lift off technology is mature, and the glass substrate 100 is not affected, so as to protect the glass substrate 100.

In this embodiment, require hydrofluoric acid to spray equipment and have the nozzle 20 and the baking chamber 30 of photoresistance coating, at lower surface spraying one deck photoresist layer 10 of glass substrate 100, when carrying out the hydrofluoric acid to passivation layer 300 and spray the sculpture, photoresist layer 10 can play the protection glass substrate 100's effect prevents that its surface from leaving the roller seal, avoids being corroded by hydrofluoric acid, just can avoid glass substrate 100 is the white dirty of water droplet form and roller seal form under macroscopic state, presents phenomena such as sand gravel form under microscopic state, can reduce the degree of difficulty of Peeling off when actual production, prevents that OLED array layer 200 from receiving the pulling and then causing display surface Peeling, lighting a lamp the back picture and appear black spot, thin black line scheduling problem, improves display panel's display effect, improves display device's yield.

As shown in fig. 14, this embodiment further provides a display panel, where the display panel is prepared by the method for preparing a display panel, and the method includes: the glass substrate 100, the OLED array layer 200, the passivation layer 300, and the planarization layer 400 further include a light emitting device, a pixel electrode, a cover plate, and the like (not shown).

OLED array layer 200 locates the surface of glass substrate 100 one side, OLED array layer 200 includes from down up in proper order: a light-shielding layer 201, a buffer layer 202, an active layer 203, a gate insulating layer 204, a gate layer 205, a dielectric layer 206, and a source electrode 207 and a drain electrode 208. The passivation layer 300 is disposed on the surface of the OLED array layer 200 far away from the glass substrate 100, and the passivation layer 300 is provided with a second through hole 301 etched by hydrofluoric acid. The flat layer 400 is arranged on the surface of one side, away from the OLED array layer 200, of the passivation layer 300, a first through hole 401 is arranged on the flat layer 400, the first through hole 401 is communicated with the second through hole 301, the formed through hole is opposite to the drain electrode 208 on the OLED array layer 200, and the through hole provides a channel for connection between a subsequent anode layer and the drain electrode 208, so that the OLED array layer 200 drives the light-emitting device to be in a circuit mode.

The display panel manufactured by the manufacturing method of the display panel can effectively avoid the corrosion of the back surface of the glass substrate in the process of etching the passivation layer by hydrofluoric acid, prevent the problems of Peeling of the display surface, black spots and thin black lines of a picture after lighting and the like caused by the pulling of the OLED array layer, improve the display effect of the display panel and improve the yield of display devices.

The display panel and the manufacturing method thereof provided by the embodiments of the present application are described in detail above, and the principle and the embodiment of the present application are explained herein by applying specific examples, and the description of the embodiments above is only used to help understanding the method and the core idea of the present application; meanwhile, for those skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims

1. A preparation method of a display panel is characterized by comprising the following steps:

providing a glass substrate;

preparing an OLED array layer on the glass substrate; and

preparing a passivation layer and a flat layer on the OLED array layer, and etching through holes on the passivation layer and the flat layer;

wherein, in the step of etching the through holes on the passivation layer and the flat layer:

arranging a light resistance layer on one side of the glass substrate far away from the OLED array layer;

carrying out hydrofluoric acid spraying treatment to form a through hole on the passivation layer;

and laser stripping the photoresist layer.

2. The method of manufacturing a display panel according to claim 1, wherein the step of manufacturing an OLED array layer on the glass substrate comprises: and sequentially preparing a shading layer, a buffer layer, an active layer, a grid insulating layer, a grid layer, a dielectric layer and a source drain electrode layer on the glass substrate.

3. The method of manufacturing a display panel according to claim 2, wherein the step of manufacturing a passivation layer and a planarization layer on the OLED array layer comprises:

depositing a layer of insulating material on the upper surfaces of the source drain electrode layer and the dielectric layer to serve as a passivation layer;

coating a layer of inorganic material on the upper surface of the passivation layer to form a flat layer;

and after exposure, development, baking and etching, forming a first through hole on the flat layer, wherein the first through hole is arranged opposite to the drain electrode in the source/drain electrode layer.

4. The method of claim 1, wherein the step of disposing a photoresist layer on the side of the glass substrate away from the OLED array layer comprises:

and spraying a light resistance material on one side of the glass substrate far away from the OLED array layer, and baking and curing.

5. The method for manufacturing a display panel according to claim 3, wherein the step of performing hydrofluoric acid shower treatment includes:

and carrying out hydrofluoric acid spraying treatment at least twice, forming a second through hole at the passivation layer below the first through hole, wherein the second through hole is communicated with the first through hole to form the through hole.

6. The method for manufacturing a display panel according to claim 5,

and after the hydrofluoric acid spraying step, carrying out air drying treatment.

7. The method for manufacturing a display panel according to claim 4,

when the photoresist material is sprayed, a roller type roller is adopted to roll on the bottom surface of the glass substrate, so that the photoresist material is uniformly sprayed.

8. The method for manufacturing a display panel according to claim 4,

in the step of performing the baking curing treatment, a heating wire or extreme ultraviolet curing treatment is adopted.

9. A display panel prepared by the method according to any one of claims 1 to 8.

10. The display panel according to claim 9, comprising:

a glass substrate;

the OLED array layer is arranged on the surface of one side of the glass substrate;

the passivation layer is arranged on the surface of one side, away from the glass substrate, of the OLED array layer, and a second through hole formed by etching through hydrofluoric acid is formed in the passivation layer;

the flat layer is arranged on the surface of one side, away from the OLED array layer, of the passivation layer, a first through hole is formed in the flat layer, the first through hole is communicated with the second through hole, and the formed through hole is opposite to the drain electrode on the OLED array layer.