WO2020155590A1

WO2020155590A1 - Display panel, preparation method therefor and display terminal

Info

Publication number: WO2020155590A1
Application number: PCT/CN2019/098453
Authority: WO
Inventors: 彭兆基; 刘明星; 甘帅燕
Original assignee: 昆山国显光电有限公司
Priority date: 2019-01-28
Filing date: 2019-07-30
Publication date: 2020-08-06
Also published as: CN209461464U

Abstract

Provided in the present application are a display panel, a preparation method therefor and a display terminal, the display panel comprising: a cover plate and a substrate which are arranged opposite to each other, a pixel definition layer being disposed between the cover plate and the substrate; a light-transmitting region is provided between the cover plate and the substrate, and an optical enhancement layer is provided within the light-transmitting region between the cover plate and the pixel definition layer.

Description

Display panel, its preparation method and display terminal

Technical field

This application relates to the technical field of display devices, and in particular to a display panel, a preparation method thereof, and a display terminal.

Background technique

Mobile phones and other electrical equipment often have front cameras to facilitate users to take selfies. In the prior art, the front camera is often arranged inside the display panel, and the front camera takes pictures through the display panel. The display panel can be set larger to increase the screen-to-body ratio. The display panel has a light-transmitting area corresponding to the front camera. There are no thin-film transistors and circuits in the array substrate in the light-transmitting area, and there is no light-emitting unit in the light-emitting layer in the light-transmitting area to avoid the influence of thin-film transistors, circuits and light-emitting units. The front camera acquires the image.

There are no thin film transistors and circuits in the array substrate in the light-transmitting area, resulting in a small thickness of the array substrate in the light-transmitting area, so that there is a gap between the pixel defining layer and the cover plate, and the gas in the gap has a large refractive index difference with the cover plate. , When light passes through the light-transmitting area, it will be refracted and reflected at the interface between the cover and the gap, which will affect the work of the front camera.

Summary of the invention

The embodiments of the present application provide a display panel, a preparation method thereof, and a display terminal, so as to solve the problem that there is a gap between the pixel defining layer and the cover plate. The gas in the gap and the cover plate have a large refractive index difference. When light passes through the light-transmitting area , There will be refraction and reflection at the interface between the cover and the gap, which will affect the technical problems of the front camera.

One aspect of the present application provides a display panel, including: a cover plate and a substrate disposed oppositely, a pixel defining layer is disposed between the cover plate and the substrate; In the light-transmitting area, an optical improvement layer is provided in the area of the light-transmitting area between the cover plate and the pixel defining layer.

Another aspect of the present application also provides a display terminal, including: a photosensitive component and the display panel as described above; the photosensitive component is arranged on the side of the substrate facing away from the cover plate, and the photosensitive component is directly opposite The light-transmitting area is provided.

Another aspect of the present application provides a method for manufacturing a display panel, including:

Provide a substrate,

Forming a transparent layer on the substrate,

Forming a planarization layer on the transparent layer,

Forming a pixel defining layer on the planarization layer,

Forming an optical improvement layer on the pixel defining layer,

A cover plate is provided on the optical improvement layer.

In the display panel and display terminal provided by the present application, there is a light-transmitting area between the cover plate and the substrate, and an optical improvement layer is arranged between the cover plate and the pixel defining layer in the light transmitting area; Compared with the gap filling air and other gases, it reduces the refractive index of the gap between the cover plate and the pixel defining layer, thereby reducing the refractive index difference between the gap and the cover plate, and avoiding the light passing through the cover plate and the gap. Refraction and reflection occur at the interface between them, so as not to affect the work of the photosensitive element.

Description of the drawings

In order to explain the embodiments of the present application or the technical solutions in the prior art more clearly, the following will briefly introduce the present application with the accompanying drawings required in the description of the embodiments or the prior art.

FIG. 1 is a schematic structural diagram of a display panel provided by an embodiment of the application;

2 is a schematic structural diagram of a display panel provided by an embodiment of the application in which a light transmission channel penetrates through a pixel defining layer;

FIG. 3 is a schematic structural diagram of a display panel provided by an embodiment of the application in which a light-transmitting channel penetrates a planarization layer;

FIG. 4 is a schematic structural diagram of a light-transmitting channel in a display panel provided by an embodiment of the application, which penetrates through all the film layers of the light-transmitting area;

5 is a schematic diagram of the same material of the optical improvement layer and the pixel defining layer in the display panel provided by the embodiment of the application;

6 is a schematic diagram of the same material of the optical improvement layer and the planarization layer in the display panel provided by the embodiment of the application.

Description of reference signs:

10. Cover plate;

20. Pixel defining layer;

30. Planarization layer;

40. Optical improvement layer;

50. Substrate;

60. Light transmission area;

401. Extension.

detailed description

In the case of no conflict in this application, the following embodiments and the features in the embodiments can be combined with each other.

Please refer to Figure 1-Figure 6. This embodiment provides a display panel, including: a cover plate 10 and a substrate 50 disposed oppositely, a pixel defining layer 20 is provided between the cover plate 10 and the substrate 50; In the area 60, an optical improvement layer 40 is provided between the cover plate 10 and the pixel defining layer 20 in the light-transmitting area 60.

The display panel includes a stacked array substrate, a pixel defining layer 20, and a cover plate 10; the array substrate has a pixel circuit layer, and the pixel circuit layer includes a stacked active layer, a gate insulating layer, a gate layer, an interlayer insulating layer, and Source drain layer. Specifically, a low-temperature polysilicon process (LTPS) can be used to prepare the above-mentioned pixel circuit layer on a substrate. In order to save the preparation process during the preparation process, the insulating layer (such as the gate insulating layer and the interlayer insulating layer) in the pixel circuit layer is usually Cover the entire substrate. Of course, in other embodiments, the above-mentioned insulating layer can also reasonably set its coverage area according to actual conditions. A first electrode electrically connected to the pixel circuit layer is provided on the side of the array substrate facing the pixel defining layer 20, and a planarization layer 30 is provided between the pixel circuit layer and the first electrode; the display panel is separated by the pixel defining layer 20. There are a plurality of open pixel areas, the pixel area is provided with an organic light emitting layer, each pixel area corresponds to a first electrode, and the second electrode is provided on the side of the pixel defining layer 20 facing away from the array substrate. When the display panel is working, the pixel circuit controls its corresponding first electrode to charge, and then forms an electric field between the first electrode and the second electrode, so that the organic light emitting layer corresponding to the pixel circuit emits light. The cover plate 10 is arranged on the side of the pixel defining layer 20 away from the array substrate. The cover plate 10 can be a glass plate or a transparent plate made of organic materials, so as to prevent the cover plate 10 from obstructing the emission of light in the pixel area.

In this embodiment, the light-transmitting area 60 is provided between the cover plate 10 and the substrate 50, and the light-transmitting area 60 is used to correspond to the photosensitive element provided on one side of the display panel. The photosensitive element can pass through the substrate 50 and transmit light. The area 60 and the cover plate 10 receive external light. The photosensitive element may include a camera module or a device that collects light such as a fingerprint module.

In this embodiment, in order to prevent the metal film layer from blocking light, there is no metal film in the array substrate in the light-transmitting area 60 and the pixel defining layer 20 in the light-transmitting area 60, so that the thickness of the array substrate corresponding to the light-transmitting area 60 is small. In turn, there is a gap between the pixel defining layer 20 corresponding to the light-transmitting area 60 and the cover plate 10, and the optical improvement layer 40 is disposed in the gap between the pixel defining layer 20 and the cover plate 10.

Specifically, the optical improvement layer 40 can be made of various materials, as long as the optical improvement layer 40 has a high light transmittance, so as to prevent the optical improvement layer 40 from blocking light from passing through; for example, the optical improvement layer 40 may be mainly made of OCA ( Optically Clear Adhesive) optical glue, or the optical improvement layer 40 is mainly composed of PET plastic (polyterephthalic acid plastic), of course, the optical improvement layer 40 can also be mainly composed of PEN (polyethylene naphthalate); The optical improvement layer 40 in this embodiment is not limited to the above-mentioned material, and may be other materials with higher light transmittance. Further, the light transmittance of the optical improvement layer 40 is not less than 80% to ensure that the photosensitive element has a better photosensitive effect.

1, in this embodiment, the optical improvement layer 40 filled between the cover plate 10 and the pixel defining layer 20 can reduce the refractive index of the gap between the cover plate 10 and the pixel defining layer 20, and the cover plate 10 and the pixel defining layer Compared with the gaps between the layers 20 containing air and other gases, the difference in refractive index between the gap between the cover plate 10 and the pixel defining layer 20 and the cover plate 10 is reduced, and the light is prevented from passing through the cover plate 10 and the gap. The refraction and reflection that occur at the interface between the photosensitive elements increase the light intensity and the photosensitive effect obtained by the photosensitive element.

The optical improvement layer 40 located between the cover plate 10 and the pixel defining layer 20 can be formed by a coating process. Of course, the optical improvement layer 40 can also be formed by a deposition process. The method for forming the optical improvement layer 40 is not done in this embodiment. limit.

In this embodiment, the refractive index of the optical improvement layer 40 is 0.8-1.2 times the refractive index of the cover plate 10. The difference in refractive index between the optical improvement layer 40 and the cover plate 10 can be further reduced, and the refraction and reflection that occur when the light passes through the interface between the cover plate 10 and the optical improvement layer filled in the gap can be further avoided. The light intensity and photosensitive effect obtained by the photosensitive element.

In one of the embodiments, the refractive index of the optical improvement layer 40 is equal to the refractive index of the cover plate 10. The reflection and refraction that occurs when light passes through the interface between the cover plate 10 and the optical improvement layer filled in the gap is eliminated, and the light intensity and the photosensitive effect obtained by the photosensitive element are further improved.

Taking the orientation shown in FIG. 1 as an example, the propagation process of light in the display panel is as follows: the light enters from the upper part of the cover plate 10, the light passes through the cover plate 10 and then enters the optical improvement layer 40 downward, and the light passes The optical improvement layer 40 is then injected downward into the pixel defining layer 20, the light passes through the pixel defining layer 20 and then downwards into the planarization layer 30, and the light enters the substrate after passing through the planarization layer 30. The inside of the bottom 50 is finally emitted from the substrate 50 of the array substrate and received by the photosensitive element.

In the display panel provided by this embodiment, a light-transmitting area 60 is provided between the cover plate 10 and the substrate 50, and an optical improvement layer 40 is provided between the cover plate 10 and the pixel defining layer 20 in the light-transmitting area 60; and the cover plate 10 Compared with the gap between the pixel defining layer 20 being filled with gas such as air, the refractive index of the gap between the cover plate 10 and the pixel defining layer 20 is reduced, thereby reducing the refractive index difference between the gap and the cover plate 10. , Avoiding the refraction and reflection that occurs when the light passes through the interface between the cover plate 10 and the gap, and improving the light intensity obtained by the photosensitive element, so as not to affect the operation of the photosensitive element.

2, in an alternative embodiment, the pixel defining layer 20 is provided with a light transmitting channel located in the light transmitting area 60, and the light transmitting channel penetrates the pixel defining layer 20; the optical improvement layer 40 includes filling in the light transmitting channel Extension 401.

In the process of passing through the pixel defining layer 20, the light is always located in the extension 401 of the optical improvement layer 40, avoiding the refraction and reflection of the light passing through the interface between the optical improvement layer 40 and the pixel defining layer 20; that is, The number of film layers that the light passes through when the light passes through the display panel is reduced, so as to further improve the light intensity and the photosensitive effect obtained by the photosensitive element.

In this embodiment, the projected area of the light-transmitting area 60 on the cover 10 may be greater than the projected area of the light-transmitting channel on the cover 10; preferably, the projected area of the light-transmitting channel and the light-transmitting area 60 on the cover 10 are equal , In order to improve the light transmittance of the entire light transmission area 60.

In an achievable manner, the entire pixel defining layer 20 may be formed first, and then a light transmitting channel may be formed in the light transmitting region 60 by drilling or laser drilling; in this embodiment, the pixel defining layer 20 may also be deposited. A shielding portion corresponding to the light-transmitting channel is formed on the mask used, and when the pixel defining layer 20 is deposited, a light-transmitting channel is formed at a position corresponding to the shielding portion. When the optical improvement layer 40 is made, the extension 401 filled in the light transmission channel is first formed, and the extension 401 is filled with the light transmission channel.

Referring to FIG. 3, in an alternative embodiment, a planarization layer 30 is provided between the substrate 50 and the pixel defining layer 20, and the light transmission channel penetrates the planarization layer 30.

The array substrate includes a pixel circuit layer and a first electrode electrically connected to the pixel circuit layer. The planarization layer 30 is disposed between the pixel circuit layer and the first electrode; the light transmission channel penetrates the planarization layer 30, and light passes through the pixel defining layer. 20 and the planarization layer 30, they only propagate in the extension 401, avoiding the refraction and reflection of light passing through the interface between the optical improvement layer 40 and the pixel defining layer 20, and also preventing the light from passing through the pixel Refraction and reflection occur when defining the interface between the layer 20 and the planarization layer 30; that is, the number of film layers that light passes through when the light passes through the display panel is reduced, and the light intensity received by the photosensitive element is further improved.

In an achievable manner, the entire planarization layer 30 and the pixel defining layer 20 can be formed first, and then a light transmission channel is formed in the light transmission area 60 by drilling or laser drilling, and the light transmission channel penetrates the pixel definition Layer 20 and planarization layer 30. In this embodiment, a first light-shielding portion corresponding to the light-transmitting channel may also be provided on the mask used for depositing the planarization layer 30, so as to form the first channel at a position corresponding to the first light-shielding portion when the planarization layer 30 is formed ; A second shielding portion corresponding to the first channel is formed on the mask used for depositing the pixel defining layer 20. When the pixel defining layer 20 is deposited, the second shielding portion forms a second channel, the first channel and the first channel The second channel is enclosed as a transparent channel. When the optical improvement layer 40 is made, the extension 401 filled in the light transmission channel is first formed, and the extension 401 is filled with the light transmission channel.

Referring to FIG. 4, in an alternative embodiment, the light transmission channel penetrates all the film layers in the light transmission area 60.

Specifically, the array substrate further includes a buffer layer and a pixel circuit layer located between the planarization layer 30 and the substrate 50, wherein the pixel circuit layer includes transparent layers such as a gate insulating layer and an interlayer insulating layer, and the light transmission channel penetrates the light transmission area All the film layers in 60, and the extension 401 is full of light transmission channels; the light only propagates in the optical improvement layer 40 in the light transmission area 60, which can further prevent the light from passing through the buffer layer, the gate insulating layer and the interlayer insulating layer. Refraction and reflection occur when the pixel defining layer 20 and the film layer outside the planarization layer 30; further reduce the number of film layers when light passes through the display panel, so as to further increase the light intensity obtained by the photosensitive element.

Referring to FIG. 6, in an alternative embodiment, the material of the optical improvement layer 40 and the planarization layer 30 are the same. This can avoid refraction and reflection of light passing through the interface between the optical improvement layer 40 and the planarization layer 30, and at the same time can reduce the type of display panel material to facilitate the processing of the display panel.

When manufacturing the display panel, first through holes may be formed on the film layer between the planarization layer 30 and the substrate 50. When the planarization layer 30 is formed, the planarization layer 30 is filled in the first through holes; A pixel defining layer 20 is formed on the planarization layer 30, and a second through hole corresponding to the light transmission channel is provided on the pixel defining layer 20, and an optical improvement layer 40 of the same material as the planarizing layer 30 is filled in the second through hole. The optical improvement layer 40 fills the second through hole.

5, in an alternative embodiment, the material of the optical improvement layer 40 and the pixel defining layer 20 are the same.

When manufacturing the display panel, the first channel may be provided on the planarization layer 30 first. When the pixel defining layer 20 is deposited on the planarizing layer 30, part of the pixel defining layer 20 fills the first channel to form an extension into the first channel The extension 401 is formed at the same time as the pixel defining layer 20; there is no need to form the extension 401 after forming the pixel defining layer 20 and the planarization layer 30 after forming the light transmission channel, which simplifies the processing process of the display panel.

In a preferred implementation, the pixel defining layer 20 and the planarization layer 30 are made of the same material. During processing, a through hole must be formed in the film layer between the planarization layer 30 and the substrate 50 to form a planarization layer. Layer 30, part of the planarization layer 30 is filled in the through holes, and then the pixel defining layer 20 is formed on the planarizing layer 30, and finally in the gap between the pixel defining layer 20 and the cover plate 10, the planarization layer 30 and The optical improvement layer 40 with the same material of the pixel defining layer; that is, the planarization layer 30 and the pixel defining layer 20 in the through hole constitute the extension 401 of the optical improving layer 40.

In a preferred implementation, the pixel defining layer 20 and the planarization layer 30 are made of the same material. During processing, a corresponding laminated structure between the substrate 50 and the cover plate 10 is formed, for example, the buffer layer planarization layer 30 and The pixel defining layer 20, and then the corresponding laminated structure between the substrate 50 and the cover plate 10 is opened by laser drilling to form a light transmission channel, and then in the gap between the pixel defining layer 20 and the cover plate 10 An optical improvement layer 40 of the same material as the planarization layer 30 and the pixel defining layer is formed, and an extension 401 filled in the light transmission channel is formed at the same time. The optical improvement layer and the extension portion can be formed by a deposition process, which is not specifically limited.

In an alternative embodiment, the refractive index of the substrate 50 is equal to the refractive index of the cover plate 10.

When the light transmission channel penetrates all the film layers in the light transmission zone 60, the refractive index of the substrate 50 is equal to the refractive index of the cover plate 10, which can prevent light from passing through the interface between the optical improvement layer 40 and the substrate 50 Refraction and reflection occur to further increase the intensity of light received by the photosensitive element.

Further, the material of the substrate 50 can be the same as the material of the cover plate 10, for example, the substrate 50 and the cover plate 10 are both made of glass plates, of course, the substrate 50 and the cover plate 10 can also be made of other organic transparent materials.

Continuing to refer to FIGS. 1 to 6, another embodiment of the present application provides a display terminal, including: a photosensitive component and the display panel as described above; the photosensitive component is disposed on the side of the substrate 50 away from the cover 10, and the photosensitive component It is arranged directly opposite to the light transmitting area 60.

The photosensitive component can be a camera module or a fingerprint module or other equipment. The structure of the display panel is substantially the same as the structure of the display panel in the foregoing embodiment, and will not be repeated here.

The display terminal can be a product or component with a display function such as a mobile phone, a tablet computer, a television, a monitor, an e-book, an e-paper, a smart watch, a notebook computer, a digital photo frame, or a navigator.

In the display terminal provided by this embodiment, a light-transmitting area 60 is provided between the cover 10 and the substrate 50 of the display panel, and an optical improvement layer 40 is provided between the cover 10 and the pixel defining layer 20 in the light-transmitting area 60; and the cover Compared with the gap between the plate 10 and the pixel defining layer 20 being filled with gas such as air, the refractive index of the gap between the cover plate 10 and the pixel defining layer 20 is reduced, thereby reducing the refractive index between the gap and the cover plate 10. The difference avoids refraction and reflection when light passes through the interface between the cover plate 10 and the gap, and improves the light intensity obtained by the photosensitive element, so as not to affect the operation of the photosensitive element.

In this application, unless expressly specified otherwise, the terms "installed", "connected", "connected", "fixed" and other terms should be interpreted broadly. For example, it may be a fixed connection or a detachable connection. Or integrally formed, which can be mechanically connected, or electrically connected, or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction between two components, unless There are other clear restrictions. For those of ordinary skill in the art, the specific meanings of the above-mentioned terms in this application can be understood according to specific circumstances.

Claims

A display panel including:

A cover plate and a substrate are arranged oppositely, and a pixel defining layer is arranged between the cover plate and the substrate;

There is a light-transmitting area between the cover plate and the substrate, and an optical improvement layer is provided in the area of the light-transmitting area between the cover plate and the pixel defining layer.
2. The display panel of claim 1, wherein the pixel defining layer is provided with a light transmission channel located in the light transmission area, and the light transmission channel penetrates the pixel defining layer.
3. The display panel according to claim 2, wherein the optical improvement layer comprises an extension part filled in the light transmission channel.
3. The display panel according to claim 2, wherein the projected areas of the light-transmitting channel and the light-transmitting area on the cover plate are equal.
3. The display panel according to claim 3, wherein a planarization layer is provided between the substrate and the pixel defining layer, and the light transmission channel penetrates the planarization layer.
7. The display panel of claim 5, wherein the pixel defining layer and the planarizing layer allow light to pass through, and then only propagate in the extension portion.
3. The display panel of claim 3, wherein the light transmission channel penetrates all the film layers in the light transmission area.
3. The display panel of claim 3, wherein the optical improvement layer and the planarization layer are made of the same material.
8. The display panel of any one of claims 1-8, wherein the optical improvement layer and the pixel defining layer are made of the same material.
The display panel of claim 1, wherein the refractive index of the substrate is equal to the refractive index of the cover plate.
The display panel of claim 1, wherein the refractive index of the optical improvement layer is 0.8-1.2 times the refractive index of the cover plate.
11. The display panel of claim 11, wherein the refractive index of the optical improvement layer is equal to the refractive index of the cover plate.
A display terminal, comprising: a photosensitive component and the display panel according to any one of claims 1-12; the photosensitive component is arranged on the side of the substrate away from the cover plate, and the photosensitive component is directly opposite The light-transmitting area is provided.
A method for preparing a display panel includes:

Provide a substrate,

Forming a transparent layer on the substrate,

Forming a planarization layer on the transparent layer,

Forming a pixel defining layer on the planarization layer,

Forming an optical improvement layer on the pixel defining layer,

A cover plate is provided on the optical improvement layer.
The method according to claim 14, wherein the transparent layer includes a buffer layer and a pixel circuit layer.
The method according to claim 14, wherein a light transmission channel is formed through at least one film layer located between the substrate and the cover plate, and the optical improvement layer includes a light transmission channel filled in the light transmission channel. Extension.
The method according to claim 14, wherein the optical improvement layer is formed by a coating process.
The method according to claim 16, wherein the light transmission channel is formed by drilling or laser drilling.
The method according to claim 16, wherein the step of forming the planarization layer, the pixel defining layer, the optical improvement layer, and the light transmission channel comprises:

First, a first through hole is formed on the transparent layer, and when the planarization layer is formed, the planarization layer is filled in the first through hole; then the pixel defining layer is formed on the planarization layer, Moreover, a second through hole corresponding to the light transmission channel is provided on the pixel defining layer, and the optical improvement layer of the same material as the planarization layer is filled in the second through hole, and the optical improvement layer The second through hole is filled.
The method according to claim 16, wherein the extension portion is formed by the following steps: firstly, a first channel is provided on the planarization layer, and when the pixel defining layer is deposited on the planarization layer, part of the The pixel defining layer fills the first channel to form an extension part extending into the first channel.