CN112086573A

CN112086573A - Display panel and preparation method thereof

Info

Publication number: CN112086573A
Application number: CN202010941631.9A
Authority: CN
Inventors: 何瑞亭; 李晓康
Original assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2020-09-09
Filing date: 2020-09-09
Publication date: 2020-12-15

Abstract

The invention provides a display panel and a preparation method thereof. The display panel comprises a flexible substrate, an array substrate and a light emitting layer. The flexible substrate has a plurality of grooves on a surface thereof. The array substrate is arranged on one surface of the flexible substrate far away from the groove. The light emitting layer is arranged on one surface of the array substrate, which is far away from the flexible substrate.

Description

Display panel and preparation method thereof

Technical Field

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

Background

Compared with other conventional display technologies, an Active-Matrix Organic Light-Emitting Diode (AMOLED) display technology has a series of advantages of lightness, thinness, high contrast, low response time, high color saturation, and the like, wherein the flexible characteristic is one of the most outstanding advantages.

The layered structure of the conventional AMOLED panel is shown in fig. 1, in which a cover plate 60 and a back plate 80 are respectively attached to two sides of a main functional film layer through adhesive layers 50. As shown in fig. 2, in the process of bending the AMOLED panel, the bending radius of one side of the back plate 80 is smaller than the bending radius of one side of the cover plate 60, and as the bending radian increases, the difference between the bending lengths of the back plate 80 and the cover plate 60 becomes larger and larger, so that a film layer Peeling phenomenon occurs, which affects the stability of the panel.

Disclosure of Invention

The invention aims to provide a display panel and a preparation method thereof, and aims to solve the problems that a Peeling phenomenon is easy to occur between a back plate and a cover plate in the prior art and the like.

In order to achieve the above object, the present invention provides a display panel including a flexible substrate, an array substrate, and a light emitting layer. The flexible substrate is provided with a plurality of grooves on one surface, and the grooves are uniformly distributed on the whole surface of the flexible substrate. The array substrate is arranged on one surface of the flexible substrate far away from the groove. The light emitting layer is arranged on one surface of the array substrate, which is far away from the flexible substrate. The display panel is provided with a bending central line, the bending central line is positioned on one side of the flexible substrate far away from the array substrate, and the display panel bends around the bending central line.

Further, the grooves are arranged on the surface of the flexible substrate in a staggered or arrayed manner.

Further, the groove is one or the combination of two of a segment shape, a table shape and a long strip shape.

Further, when the groove is in a long strip shape, one side with the longest length is parallel to the bending central line.

Further, the thickness of the flexible substrate is 10 micrometers-200 micrometers. The depth of the groove is greater than half of the thickness of the flexible substrate.

Further, the display panel further comprises an encapsulation layer, a cover plate and a glue layer. The packaging layer is arranged on one surface of the light-emitting layer far away from the array substrate. The cover plate is arranged on one surface of the luminous layer far away from the packaging layer. The glue layer is arranged between the packaging layer and the cover plate.

The invention also provides a preparation method of the display panel, which is used for preparing the display panel. The preparation method of the display panel comprises the following steps:

providing a substrate: a plurality of protruding structures are arranged on one surface of the substrate. And forming a flexible substrate on one surface of the substrate with the convex structures. And sequentially forming an array substrate and a light-emitting layer on one surface of the flexible substrate far away from the substrate. The substrate is peeled by laser techniques.

Further, the convex structure is one or the combination of two of a segment shape, a platform body shape and a long strip shape.

Further, the protruding structures are arranged on the surface of the substrate in a staggered or arrayed manner.

Further, before the step of peeling off the substrate, the method further comprises the following steps: and forming an encapsulation layer on the light-emitting layer. And attaching the cover plate to one surface of the packaging layer far away from the light-emitting layer through an adhesive layer.

The invention has the advantages that: according to the display panel, the polyimide is used as the flexible substrate, the groove is formed in the bent inner side of the flexible substrate, stress caused by bending is further relieved, and bent wrinkles are reduced, so that a Peeling phenomenon is avoided, and the stability of the display panel is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, 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 schematic diagram of a prior art display panel;

FIG. 2 is a schematic view illustrating a bending structure of a display panel in the prior art;

FIG. 3 is a schematic view of a layered structure of a display panel according to embodiments 1-2 of the present invention;

FIG. 4 is a schematic view of a layered structure of a display panel according to embodiments 1-2 of the present invention;

fig. 5 is a schematic view of a bending structure of a display panel in embodiment 1-2 of the present invention;

fig. 6 is a schematic diagram of an array arrangement of grooves in embodiment 1 of the present invention;

fig. 7 is a schematic view of the staggered arrangement of the grooves in embodiment 1 of the present invention;

FIG. 8 is a schematic flow chart illustrating a method for manufacturing a display panel according to embodiment 1 of the present invention;

FIG. 9 is a schematic view showing the layered structure of a spherical segment-shaped projection structure in example 1 of the present invention;

FIG. 10 is a schematic view showing a layered structure of a mesa-shaped convex structure in example 1 of the present invention;

FIG. 11 is a schematic view of the layered structure after step S20 in example 1 of the present invention;

FIG. 12 is a schematic view of the layered structure after step S30 in example 1 of the present invention;

FIG. 13 is a schematic view of the layered structure after step S40 in example 1 of the present invention;

fig. 14 is a schematic layout view of the grooves in embodiment 2 of the present invention.

The components in the figures are represented as follows:

a display panel 100;

a flexible substrate 10; a groove 11;

an array substrate 20; a light-emitting layer 30;

an encapsulation layer 40; a glue layer 50;

a cover plate 60; a substrate 70;

raised structures 71; a back plate 80;

a functional film layer 90; the centre line 101 is bent.

Detailed Description

The preferred embodiments of the present invention will be described below with reference to the accompanying drawings, which are included to demonstrate that the invention can be practiced, and to provide those skilled in the art with a complete description of the invention so that the technical content thereof will be more clear and readily understood. The present invention may be embodied in many different forms of embodiments and should not be construed as limited to the embodiments set forth herein.

In the drawings, structurally identical elements are represented by like reference numerals, and structurally or functionally similar elements are represented by like reference numerals throughout the several views. The size and thickness of each component shown in the drawings are arbitrarily illustrated, and the present invention is not limited to the size and thickness of each component. The thickness of the components may be exaggerated where appropriate in the figures to improve clarity.

Furthermore, the following description of the various embodiments of the invention refers to the accompanying drawings that illustrate specific embodiments of the invention, by which the invention may be practiced. Directional phrases used in this disclosure, such as, for example, "upper," "lower," "front," "rear," "left," "right," "inner," "outer," "side," and the like, refer only to the orientation of the appended drawings and are, therefore, used herein for better and clearer illustration and understanding of the invention, and do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

When certain components are described as being "on" another component, the components can be directly on the other component; there may also be an intermediate member disposed on the intermediate member and the intermediate member disposed on the other member. When an element is referred to as being "mounted to" or "connected to" another element, they may be directly "mounted to" or "connected to" the other element or indirectly "mounted to" or "connected to" the other element through an intermediate element.

Example 1

The embodiment of the invention provides a display device, which comprises a display panel 100, wherein the display panel 100 is used for providing a display picture for the display device. The display device can be any product or component with a display function, such as a mobile phone, a tablet computer, a notebook computer and the like.

As shown in fig. 3, the display panel 100 includes a flexible substrate 10, an array substrate 20, a light emitting layer 30, an encapsulation layer 40, and a cover plate 60.

The array substrate 20 is disposed on a surface of the flexible substrate 10, the array substrate 20 has a plurality of Thin Film Transistor (TFT) devices therein, the TFT devices are arranged in the array substrate 20 in an array, and each TFT device is electrically connected to the light-emitting layer 30.

The light emitting layer 30 is disposed on a surface of the array substrate 20 away from the flexible substrate 10. In the embodiment of the present invention, the light-emitting layer 30 has a plurality of RGB (red, green, and blue) sub-pixels, and each sub-pixel is connected to a TFT device in the array substrate 20. The TFT device controls whether each sub-pixel emits light or not like a switch, and independent light emission of each sub-pixel is realized. The light emitted by each sub-pixel is combined with the light emitted by the adjacent sub-pixels with different RGB into different colors, so that color display is realized.

The array substrate 20 transmits electric energy to the light emitting layer 30, electrons and holes in the light emitting layer 30 move and combine under the driving of an electric field to generate excitons, and the excitons transfer energy to organic light emitting molecules under the action of the electric field to excite the organic light emitting molecules to emit light, so that the electric energy is converted into light energy to realize the light emission of the device.

The encapsulation layer 40 is disposed on a surface of the light emitting layer 30 away from the array substrate 20. The encapsulation layer 40 is used to protect the light emitting layer 30, prevent water and oxygen from invading and corroding the devices in the light emitting layer 30, and prolong the service life of the display panel 100. Meanwhile, the Encapsulation layer 40 is prepared by adopting a Thin-Film Encapsulation (TFE) technology, and the adhesion between the Film layers of the Encapsulation layer 40 is improved while the barrier effect is enhanced by a sandwich-type lamination structure of organic materials and inorganic materials.

The cover plate 60 is disposed on a surface of the encapsulation layer 40 away from the light-emitting layer 30, and is used for protecting the overall structure of the display panel 100. A glue layer 50 is also provided between the cover plate 60 and the encapsulation layer 40. The adhesive layer 50 is an optical adhesive (OCA) for increasing the adhesion between the cover plate 60 and the encapsulation layer 40.

The material of the flexible substrate 10 is Polyimide (PI) with a thickness of 10-200 microns, preferably 80 microns. When the display panel 100 is bent, the display panel 100 has a bending center line 101, as shown in fig. 5, the bending center line 101 is located on the flexible substrate 10 away from the array substrate 20, so when the display panel 100 is bent and wound, the flexible substrate 10 is located on the inner side of the display panel 100, and the bending radius of the inner side is smaller than that of the outer side, so that the flexible substrate 10 located on the inner side and the cover plate 60 located on the outer side can generate a difference in the bending length when bent and wound. However, the flexible substrate 10 made of polyimide has superior flexibility compared to the back plate 80 of the related art, and can contract its own length when bent, thereby reducing a difference in a curled length due to a difference in inner and outer radii, and preventing a Peeling phenomenon.

The flexible substrate 10 has a plurality of grooves 11 on a surface thereof away from the array substrate 20. The recess 11 may be in the shape of a segment of a sphere as shown in fig. 3, or in the shape of a frustum as shown in fig. 4. The frustum shape can be a circular truncated cone shape or a truncated pyramid shape. The grooves 11 are uniformly distributed on the entire surface of the flexible substrate 10, and the distribution rule may be an array arrangement method as shown in fig. 6, or a staggered arrangement method as shown in fig. 7.

The distance between the groove bottom of the groove 11 and the surface of the flexible substrate 10 close to the array substrate 10 is less than half of the thickness of the flexible substrate 10, that is, the depth of the groove 11 is greater than half of the thickness of the flexible substrate 10, and the depth range of the groove 10 is greater than 5 micrometers and less than 200 micrometers. When the depth of the groove 11 is larger, the effect of relieving the bending stress is better, but the groove 11 cannot penetrate through the flexible substrate 10, so that the effect is best when the depth of the groove 11 is larger than half of the thickness of the flexible substrate 10 and smaller than the thickness of the flexible substrate 10, and at the moment, the thickness of the thinnest part of the flexible substrate 10 is smaller than half of the thickness of the thickest part of the flexible substrate.

When the display panel 100 is bent, the flexible substrate 10 located inside the bend is pressed due to the smaller bending radius, and the groove 11 can reduce the bending perimeter of the inner side of the flexible substrate 10 after bending, reduce the bending wrinkles, and make the flexible substrate 10 have a space to release the stress generated by pressing after bending, thereby further reducing the risk of preventing the Peeling phenomenon, and improving the stability of the display panel 100.

The embodiment of the present invention further provides a method for manufacturing the display panel 100, wherein the manufacturing process is shown in fig. 8, and the method includes the following specific steps:

step S10) provides a substrate 70: the substrate 70 is an insulating substrate such as a glass substrate or a quartz substrate. The substrate 70 has a plurality of protruding structures 71 on a surface thereof. The raised structure 71 may be in the shape of a segment of a sphere as shown in fig. 9, or may be in the shape of one of the platforms as shown in fig. 10. Wherein, the frustum shape can be a circular truncated cone shape or a prismoid shape. The distribution rule of the protruding structures 71 on the substrate 70 is the same as the distribution rule of the grooves 11 on the flexible substrate 10.

Step S20) forms the flexible substrate 10: a polyimide material is coated on one surface of the substrate 70 having the projection structures 71, and is cured to form a film, thereby forming the flexible substrate 10 shown in fig. 11.

Step S30) forming the array substrate 20, the light-emitting layer 30, and the encapsulation layer 40: the array substrate 20 is formed on a surface of the flexible substrate 10 away from the substrate 70 by a TFT process. The light emitting layer 30 is then formed on a surface of the array substrate 20 away from the flexible substrate 10 by ink jet printing or the like. Finally, the encapsulation layer 40 is formed on a surface of the light emitting layer 30 away from the array substrate 20 by a thin film encapsulation technique, so as to form a layered structure as shown in fig. 12.

Step S40) attaching the cover plate 60: a transparent glass cover plate 60 is prepared, and the cover plate 60 is attached to a surface of the encapsulation layer 40 away from the light-emitting layer 30 through the adhesive layer 50, so as to form a layered structure as shown in fig. 13.

Step S50) peeling the substrate 70: the underlying substrate 70 is peeled off by a laser separation technique to finally form the display panel 100 as shown in fig. 3.

According to the display panel 100 and the display device provided by the embodiment of the invention, polyimide is adopted as the flexible substrate 10, and the excellent flexibility of the polyimide flexible substrate 10 is utilized to enable the polyimide flexible substrate to shrink the length of the polyimide flexible substrate when being bent, so that the difference of the curling length caused by the different radiuses of the inner side and the outer side of the bending can be reduced, and the Peeling phenomenon is further prevented. Meanwhile, the embodiment of the invention further relieves the stress caused by bending by arranging the groove 11 at the inner side of the bending of the flexible substrate 10, and reduces the generation of bending wrinkles, thereby avoiding the Peeling phenomenon and improving the stability of the display panel 100.

Example 2

The flexible substrate 10 has a plurality of grooves 11 on a surface thereof away from the array substrate 20. The groove 11 is a long strip, and the cross section thereof may be an arc shape as shown in fig. 3, or a trapezoid shape as shown in fig. 4. As shown in fig. 14, the grooves 11 are arranged in an array on the entire surface of the flexible substrate 10, and the longest side of the elongated grooves 11 is parallel to the bending center line 101.

The embodiment of the present invention may also be manufactured by using the manufacturing method provided in embodiment 1, and the only difference is that the protrusion structures 71 of the substrate 70 are different, the protrusion structures 71 on the substrate 70 used in the embodiment of the present invention are matched with the elongated grooves 11 in batch, and the remaining manufacturing process is similar to that in embodiment 1, and therefore not described herein again.

Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that features described in different dependent claims and herein may be combined in ways different from those described in the original claims. It is also to be understood that features described in connection with individual embodiments may be used in other described embodiments.

Claims

1. A display panel, comprising:

the flexible substrate is provided with a plurality of grooves on one surface, and the grooves are uniformly distributed on the whole surface of the flexible substrate;

the array substrate is arranged on one surface of the flexible substrate away from the groove;

and the light-emitting layer is arranged on one surface of the array substrate, which is far away from the flexible substrate.

2. The display panel of claim 1, wherein the grooves are arranged in a staggered arrangement or an array arrangement on the surface of the flexible substrate.

3. The display panel of claim 1, wherein the grooves are one or a combination of a segment shape, a mesa shape, and a stripe shape.

4. The display panel according to claim 3, wherein the display panel has a bending center line, the bending center line is located on a side of the flexible substrate away from the array substrate, and the display panel is bent around the bending center line;

when the groove is in a long strip shape, one side with the longest length is parallel to the bending central line.

5. The display panel of claim 1,

the thickness of the flexible substrate is 10-200 microns;

the depth of the groove is greater than half of the thickness of the flexible substrate.

6. The display panel of claim 1, further comprising:

the packaging layer is arranged on one surface of the light-emitting layer, which is far away from the array substrate;

the cover plate is arranged on one surface of the luminous layer far away from the packaging layer;

and the adhesive layer is arranged between the packaging layer and the cover plate.

7. A method of manufacturing a display panel according to any one of claims 1 to 6, comprising the steps of:

providing a substrate: a plurality of protruding structures are arranged on one surface of the substrate;

forming a flexible substrate on one surface of the substrate with the convex structures;

sequentially forming an array substrate and a light-emitting layer on one surface of the flexible substrate far away from the substrate;

the substrate is peeled by laser techniques.

8. The method for manufacturing a display panel according to claim 7, wherein the protrusion structure is one or a combination of two of a segment shape, a mesa shape and a stripe shape.

9. The method for manufacturing a display panel according to claim 7, wherein the protruding structures are arranged on the surface of the substrate in a staggered arrangement or an array arrangement.

10. The method for manufacturing a display panel according to claim 7, further comprising, before the step of peeling the substrate, the steps of:

forming an encapsulation layer on the light emitting layer;

and attaching the cover plate to one surface of the packaging layer far away from the light-emitting layer through an adhesive layer.