WO2020248431A1

WO2020248431A1 - Method for preparing display panel, and display panel

Info

Publication number: WO2020248431A1
Application number: PCT/CN2019/107403
Authority: WO
Inventors: 王一佳; 张明
Original assignee: 武汉华星光电半导体显示技术有限公司
Priority date: 2019-06-14
Filing date: 2019-09-24
Publication date: 2020-12-17
Also published as: CN110246880A; CN110246880B

Abstract

A method for preparing a display panel, and a display panel. The method comprises: stripping a glass substrate (110) in a lower substrate in an existing display panel; and converting at least a part of a flexible substrate (210) in the lower substrate into a graphene flexible substrate (220) with a graphene structure. A display panel can be subjected to rapid heat dissipation by means of the good heat conduction performance of graphene, and the original foam/graphite/copper foil three-in-one heat dissipation structure is replaced with a graphene flexible substrate, such that the thickness of the display panel is reduced.

Description

Preparation method of display panel and display panel

Technical field

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

Background technique

Display panels, such as Organic Light-Emitting Diode (OLED for short), have attracted great attention from academia and industry because of their huge development potential in solid-state lighting and flat panel displays. Flexible OLED displays are a hot development direction in the display industry due to their low power consumption, high resolution, fast response, and flexibility. The thinner the thickness, the greater the market competitiveness. At present, flexible materials such as polyimide (PI) or polyethylene terephthalate (PET) are usually used as substrates, and thin-film crystal diodes (Thin Film transistor, TFT), OLED, thin film encapsulation (TFE), and then continue to prepare polarizers and encapsulation above.

technical problem

In order to drive TFTs, circuits need to be prepared on the bottom of the flexible substrate. When the display panel is working, the current passing through the TFT circuit will generate heat. In order to facilitate heat dissipation, a back plate (BP) and a foam/graphite/copper foil three-in-one structure is usually added on the back of the polyimide film, including acrylic foam , Graphite, copper foil (Cu coil), but the thickness of the three-in-one structure is larger, 50-100um; and the graphite is a sheet-layer structure, and the heat is mainly conducted along the sheet-layer direction, so the heat dissipation effect of the display panel is not ideal.

Technical solutions

The present invention addresses the problems of large thickness of the display panel in the prior art and poor heat dissipation effect, and proposes a method for manufacturing a display panel and a display panel.

In the first aspect, the present invention provides a method for manufacturing a display panel, the method including:

Provide glass substrate;

Forming a flexible substrate on the glass substrate;

Preparing an array layer, a light-emitting layer and an encapsulation layer in sequence on the flexible substrate;

Peeling off the glass substrate on the flexible substrate;

At least a part of the flexible substrate is converted into a graphene flexible substrate having a graphene structure.

Further, the peeling off the glass substrate on the flexible substrate includes:

The glass substrate on the flexible substrate is peeled off by laser cutting.

Further, the converting at least a part of the flexible substrate into a graphene flexible substrate with a graphene structure includes:

At least a part of the flexible substrate is converted into a graphene flexible substrate with a graphene structure through a laser induction process.

Further, the power of the laser in the laser induction process is between 0.5-3W.

Further, the laser component for laser induction of the flexible substrate is carbon dioxide.

Further, the material of the flexible substrate is a polymer precursor.

Further, the polymer precursor is polyimide or polysulfone.

Further, the method further includes: attaching a thermally conductive metal to the back of the graphene flexible substrate for heat dissipation.

Further, the thermally conductive metal is copper foil.

Further, the method further includes: sequentially performing a module process above the packaging layer to protect the display panel.

Further, the preparing an encapsulation layer on the flexible substrate includes:

A plurality of organic film layers and inorganic film layers are prepared on the flexible substrate.

Further, the plurality of organic film layers and inorganic film layers are formed by overlapping inorganic/organic/inorganic multilayer films.

Further, the graphene structure in the graphene flexible substrate is a vertical convex structure, so that heat is conducted through a vertical path.

In a second aspect, the present application also provides a display panel, the display panel including:

A flexible substrate, at least a part of the flexible substrate is a graphene flexible substrate with a graphene structure;

An array layer located above the graphene flexible substrate;

A light-emitting layer located above the array layer;

The encapsulation layer is located above the light-emitting layer.

Further, the display panel further includes a thermally conductive metal located under the graphene flexible substrate and bonded to the graphene flexible substrate.

Further, the thermally conductive metal is copper foil.

Further, the encapsulation layer includes a plurality of organic film layers and inorganic film layers.

Further, the material of the flexible substrate is a polymer precursor.

Further, the polymer precursor is polyimide or polysulfone.

Further, the graphene structure in the graphene flexible substrate is a vertical convex structure, so that heat can be conducted through a vertical path.

Beneficial effect

The present invention provides a method for preparing a display panel and a display panel. The glass substrate in the lower substrate in the existing display panel is peeled off, and at least part of the flexible substrate in the lower substrate is changed into graphite with a graphene structure. The ene flexible substrate quickly dissipates heat from the display panel through the good thermal conductivity of graphene. At the same time, the graphene flexible substrate replaces the original foam/graphite/copper foil three-in-one heat dissipation structure in the display panel, reducing the thickness of the display panel.

Description of the drawings

In order to explain the embodiments or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are merely inventions For some embodiments, those of ordinary skill in the art can obtain other drawings based on these drawings without creative work.

1 is a schematic flowchart of an embodiment of a method for manufacturing a display panel provided by the present invention;

2 is a schematic structural diagram of an embodiment of a display panel prepared in step S2 provided by the present invention;

FIG. 3 is a flowchart of an embodiment of step S3 provided by the present invention;

4 is a schematic structural diagram of an embodiment of a display panel prepared in step S3 provided by the present invention;

5 is a schematic structural view of an embodiment of a display panel after the glass substrate is peeled off according to the present invention;

FIG. 6 is a schematic structural diagram of an embodiment of converting a flexible substrate provided by the present invention into a graphene substrate

7 is a schematic diagram of the structure of an embodiment of the display panel after the module process is completed according to the present invention;

FIG. 8 is a schematic structural diagram of an embodiment of a display panel provided by the present invention.

Embodiments of the invention

The description of the following embodiments refers to the attached drawings to illustrate specific embodiments that the present invention can be implemented. The directional terms mentioned in the present invention, such as [Up], [Down], [Front], [Back], [Left], [Right], [Inner], [Outer], [Side], etc., are for reference only The direction of the additional schema. Therefore, the directional terms used are used to describe and understand the present invention, rather than to limit the present invention. In the figure, units with similar structures are indicated by the same reference numerals.

The drawings and descriptions are to be regarded as illustrative in nature and not restrictive. In the figure, units with similar structures are indicated by the same reference numerals. In addition, for understanding and ease of description, the size and thickness of each component shown in the drawings are arbitrarily shown, but the present invention is not limited thereto.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. In the drawings, the thickness of some layers and regions are exaggerated for the convenience of understanding and description. It should be noted that when a component such as a layer, film, region or substrate is referred to as being "on" another component. The component may be directly on the other component, or an intermediate component may also be present.

In addition, in the specification, unless expressly described to the contrary, the word "comprising" will be understood as meaning including the components, but does not exclude any other components. In addition, in the specification, "on" means to be located above or below the target component, and does not mean that it must be located on the top based on the direction of gravity.

In order to further explain the technical means and effects of the present invention to achieve the predetermined invention, in conjunction with the accompanying drawings and preferred embodiments, the method for manufacturing the display panel and the display panel according to the present invention, its specific implementation, structure, The characteristics and effects are detailed below.

The present invention addresses the problems of large thickness of the display panel in the prior art and poor heat dissipation effect, and proposes a method for manufacturing a display panel. FIG. 1 is a schematic flow chart of an embodiment of the method for manufacturing a display panel provided by the present invention. .

The preparation method of the display panel includes:

S1. Provide a glass substrate.

S2, forming a flexible substrate on the glass substrate.

S3. An array layer, a light-emitting layer and an encapsulation layer are sequentially prepared on the flexible substrate.

S4, peeling off the glass substrate on the flexible substrate.

S5: Convert at least a part of the flexible substrate into a graphene flexible substrate with a graphene structure.

The method for preparing a display panel provided by the present invention peels off the glass substrate in the lower substrate in the existing display panel, and at the same time converts at least a part of the flexible substrate in the lower substrate into a graphene flexible substrate with a graphene structure , The display panel is quickly dissipated through the good thermal conductivity of graphene, and the graphene flexible substrate replaces the original foam/graphite/copper foil three-in-one heat dissipation structure in the display panel, reducing the thickness of the display panel.

As shown in FIG. 2, it is a schematic structural diagram of an embodiment of a display panel prepared in step S2 provided by the present invention, in which a flexible substrate 210 is prepared above the glass substrate 110. In some embodiments of the present invention, in the step S2, the flexible substrate is formed on the glass substrate. The material of the flexible substrate is a type of polymer precursor.

Specifically, the polymer precursor may be an organic substance such as polyimide or polysulfone.

The method for preparing the flexible substrate may adopt an organic coating method to prepare the flexible substrate.

In some other embodiments of the present invention, as shown in FIG. 3, it is a flowchart of an embodiment of step S3 provided by the present invention. In step S3, an array layer, a light emitting layer, and an encapsulation layer are sequentially prepared on the flexible substrate. Can include:

S301, preparing an array layer on the flexible substrate.

Specifically, preparing the array layer 310 on the flexible substrate may include preparing a buffer layer, a TFT layer, a planarization layer, an anode, and a pixel definition layer on the flexible substrate.

S302, preparing a light-emitting layer on the array layer.

Specifically, preparing the light-emitting layer 320 on the array layer may include preparing a hole injection/transport layer, a light-emitting layer, an electron transport/injection layer, and a cathode on the array layer.

S303, preparing an encapsulation layer on the light-emitting layer.

Specifically, preparing the encapsulation layer 330 on the light-emitting layer 320 may include preparing a plurality of organic film layers and inorganic film layers on the light-emitting layer to encapsulate the display panel.

Wherein, the plurality of organic film layers and inorganic film layers may be formed by overlapping inorganic/organic/inorganic multilayer films.

It should be noted that, in the embodiment of the present invention, the specific method for preparing the array layer 310, the light emitting layer 320 and the encapsulation layer 330 can refer to the prior art, which is not limited here.

As shown in FIG. 4, it is a schematic structural diagram of an embodiment of a display panel prepared in step S3 provided by the present invention, in which the array layer 310, the light emitting layer 320 and the encapsulation layer 330 are sequentially prepared on the flexible substrate 210.

As shown in FIG. 5, it is a schematic structural view of an embodiment of the display panel after the glass substrate is peeled off provided by the present invention. In some embodiments of the present invention, the glass substrate on the flexible substrate of the glass in step S4 may include: laser-stripping the glass substrate to separate the glass substrate from the flexible substrate.

As shown in FIG. 6, it is a schematic structural diagram of an embodiment in which the flexible substrate provided by the present invention is transformed into a graphene substrate. In some embodiments of the present invention, step S5 transforming the flexible substrate into a graphene flexible substrate having a graphene structure includes:

Laser induction is performed on the flexible substrate 210 after laser ablation, so as to convert at least a portion of the flexible substrate 210 after laser ablation into a graphene flexible substrate having a graphene structure.

Specifically, in some embodiments of the present invention, after laser peeling of the flexible substrate 210, the original glass substrate 110 is peeled off. At this time, the flexible substrate 210 is laser-induced, so that a part of the flexible substrate 210 is laser-induced Under the action of, it transforms into a graphene flexible substrate with a graphene structure.

In other embodiments of the present invention, laser induction is performed on the flexible substrate 210 after laser lift-off, and the entire flexible substrate 210 can also be transformed into a graphene flexible substrate with a graphene structure.

Wherein, the laser component of the laser-induced laser-stripped flexible substrate may be carbon dioxide, and the laser-induced process needs to be performed in an atmospheric environment or an argon environment.

In some embodiments of the present invention, the laser-induced laser power is between 0.5-3W.

Specifically, the laser-induced laser power can be 0.5W, 1W, 3W, etc.

After the laser-stripped flexible substrate is laser-induced, at least a portion of the flexible substrate 210 is transformed into a flexible substrate 220 with a graphene structure, and the graphene structure is a vertical convex structure, so that the heat generated by the display panel can be reduced. Diffusing out along the vertical convex structure shortens the heat dissipation path, so that heat can be dissipated faster, and the heat dissipation effect is improved.

In some embodiments of the present invention, the manufacturing method of the display panel may further include: sequentially performing a module process on the packaging layer to protect the display panel. As shown in FIG. 7, it is a schematic diagram of the structure of an embodiment of the display panel after the module process is completed according to the present invention.

Specifically, the sequential module process on the packaging layer may include: preparing an optical glue 410 on the packaging layer 330; preparing a touch module 420 on the optical glue 410; preparing a polarizer 430 on the touch module 420 ; Prepare a cover plate 440 on the polarizer 430.

It should be noted that, for sequentially performing the above-mentioned module processes on the packaging layer, reference may be made to the prior art, which is not limited here.

In some embodiments of the present invention, the method for manufacturing the display panel may further include: laminating the metal layer 510 on the back of the graphene flexible substrate formed after laser induction to perform faster heat dissipation.

Specifically, the metal layer may be a copper foil. Since metal copper has good heat dissipation characteristics, it can better dissipate heat to the display panel.

The present invention also provides a display panel. As shown in FIG. 8, it is a schematic structural diagram of an embodiment of the display panel provided by the present invention. In some embodiments of the present invention, the display panel may include:

Graphene flexible substrate 220;

The array layer 320 is located above the graphene flexible substrate 220;

The light-emitting layer 330 is located above the array layer 320;

The encapsulation layer 340 is located above the light-emitting layer 330.

The display panel provided by the present invention peels off the glass substrate in the lower substrate in the existing display panel, and at the same time transforms at least a part of the flexible substrate in the lower substrate into a graphene flexible substrate with a graphene structure. The good thermal conductivity of ene quickly dissipates the heat of the display panel, and the graphene flexible substrate replaces the original foam/graphite/copper foil three-in-one heat dissipation structure in the display panel, reducing the thickness of the display panel.

In some embodiments of the present invention, the array layer 310 may include: a buffer layer, a TFT layer, a planarization layer, an anode, and a pixel definition layer.

In some embodiments of the present invention, the light-emitting layer 320 may include: a hole injection/transport layer, a light-emitting layer, an electron transport/injection layer, and a cathode.

In some embodiments of the present invention, the encapsulation layer 330 may include a plurality of organic film layers and inorganic film layers to encapsulate the display panel.

On the basis of the above-mentioned embodiments, in other embodiments of the present invention, the display panel may further include: an optical glue 410, a touch module 420, a polarizer 430, and a cover plate 440 which are sequentially prepared above the encapsulation layer 330.

In some embodiments of the present invention, the display panel may further include a metal layer 510 located on the lower surface of the graphene flexible substrate 310 and attached to the back of the graphene flexible substrate 310. The heat conduction of metal dissipates the heat.

According to the above objective of the present invention, a display panel is provided, including the above-mentioned manufacturing method of the display panel. The working principle of the display panel provided in this embodiment is consistent with the working principle of the foregoing embodiment of the manufacturing method of the display panel. For the specific structural relationship and working principle, please refer to the foregoing embodiment of the manufacturing method of the display panel, which will not be repeated here.

It should be noted that, based on the explanation and elaboration of the above specification, those skilled in the art of the present invention can also change and modify the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some equivalent modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the present invention.

Claims

A method for manufacturing a display panel, wherein the method includes:

Provide glass substrate;

Forming a flexible substrate on the glass substrate;

Preparing an array layer, a light emitting layer and an encapsulation layer in sequence on the flexible substrate;

Peeling off the glass substrate on the flexible substrate;

At least a part of the flexible substrate is converted into a graphene flexible substrate having a graphene structure.
The manufacturing method of the display panel according to claim 1, wherein the peeling off the glass substrate on the flexible substrate comprises:

The glass substrate on the flexible substrate is peeled off by laser cutting.
The manufacturing method of the display panel according to claim 1, wherein the converting at least a part of the flexible substrate into a graphene flexible substrate having a graphene structure comprises:

At least a part of the flexible substrate is converted into a graphene flexible substrate with a graphene structure through a laser induction process.
3. The method for manufacturing a display panel according to claim 3, wherein the power of the laser in the laser induction process is between 0.5 and 3 W.
The method for manufacturing the display panel according to claim 3, wherein the laser component for laser-induced laser induction of the flexible substrate is carbon dioxide.
The manufacturing method of the display panel according to claim 1, wherein the material of the flexible substrate is a polymer precursor.
The method for manufacturing a display panel according to claim 6, wherein the polymer precursor is polyimide or polysulfone.
The manufacturing method of the display panel according to claim 1, wherein the method further comprises: attaching a thermally conductive metal to the back surface of the graphene flexible substrate for heat dissipation.
8. The method for manufacturing a display panel according to claim 8, wherein the thermally conductive metal is copper foil.
4. The method for manufacturing a display panel according to claim 1, wherein the method further comprises: sequentially performing a module process above the encapsulation layer to protect the display panel.
The manufacturing method of the display panel according to claim 1, wherein the preparing an encapsulation layer on the flexible substrate comprises:

A plurality of organic film layers and inorganic film layers are prepared on the flexible substrate.
11. The method for manufacturing a display panel according to claim 11, wherein the plurality of organic film layers and inorganic film layers are formed by overlapping inorganic/organic/inorganic multilayer films.
The manufacturing method of the display panel according to claim 1, wherein the graphene structure in the graphene flexible substrate is a vertical convex structure, so that heat is conducted through a vertical path.
A display panel, wherein the display panel includes:

A flexible substrate, at least a part of the flexible substrate is a graphene flexible substrate with a graphene structure;

An array layer located above the graphene flexible substrate;

A light-emitting layer located above the array layer;

The encapsulation layer is located above the light-emitting layer.
14. The display panel according to claim 14, wherein the display panel further comprises a thermally conductive metal located under the graphene flexible substrate and bonded to the graphene flexible substrate.
The display panel of claim 15, wherein the thermally conductive metal is copper foil.
15. The display panel of claim 14, wherein the encapsulation layer includes a plurality of organic film layers and inorganic film layers.
The display panel according to claim 14, wherein the material of the flexible substrate is a polymer precursor.
The display panel according to claim 18, wherein the polymer precursor is polyimide or polysulfone.
15. The display panel of claim 14, wherein the graphene structure in the graphene flexible substrate is a vertical convex structure, so that heat can be conducted through a vertical path.