CN115631700A

CN115631700A - Display panel

Info

Publication number: CN115631700A
Application number: CN202211166254.1A
Authority: CN
Inventors: 汪文强
Original assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2022-09-23
Filing date: 2022-09-23
Publication date: 2023-01-20

Abstract

The embodiment of the application discloses a display panel, which comprises at least one bending area, plane areas positioned on two sides of the bending area and a back plate body; the back plate support piece is arranged on one side surface of the back plate body; the bonding layer is arranged between the back plate body and the back plate support member, and the bonding layer is only positioned in the plane area; a groove is formed in one side surface, close to the back plate supporting piece, of the back plate body and/or one side surface, close to the back plate body, of the back plate supporting piece, the groove is located at the edge, close to the bending area, of the plane area, and the bonding layer fills the groove. The beneficial effects of this application embodiment lie in, a display panel of this application embodiment has got rid of the tie coat of district of buckling, has reduced the thickness of display panel district of buckling, resists the shear stress when display panel buckles through increasing the thickness that the tie coat is close to district one end of buckling, avoids the tie coat problem of coming unstuck to appear when buckling.

Description

Display panel

Technical Field

The application relates to the field of backplanes, in particular to a display panel.

Background

With the continuous deepening and breakthrough of the flexible OLED technology research, a complete industrial layout has been formed in the global scope, and the folding mobile phone is more and more favored by consumers. The folding mobile phone product is a mainstream product of the future mobile phone market. By virtue of the superior performance of the OLED, terminal display products, such as mobile phones and notebook computers, are gradually developing to be light and thin. Under such background conditions, the yield improvement and reliability of the OLED module are one of the technical issues in the current stage. In order to improve the production yield of the OLED module, the bending stress of the folded screen is required to be managed and designed. The most effective way to achieve this is to reduce the film thickness and improve the stack design.

In order to reduce the bending stress of the module as much as possible, the adhesive layer between the back plate and the back plate supporting member of the OLED module is usually designed in a sectional manner, i.e. the bending region at the bottom layer of the back plate is not adhered with adhesive, so as to break the back plate and the back plate supporting member in the thickness direction, thereby reducing the thickness of the module at the bending region to reduce the bending stress. However, as shown in fig. 1, since the adhesive layer at the bending region is broken, if the adhesive layer is thinner or the adhesive force between the adhesive layer and the upper and lower film layers is insufficient, the module debonding phenomenon occurs at the left and right positions of the segmented adhesive, and the bubble bulging phenomenon is gradually caused, that is, the local stress of the adhesive layer near the bending region is discontinuous or too large in the module bending process, which causes the excessive adhesive or debonding to be the main cause of the bubble formation. This phenomenon directly affects the improvement of the production yield of the folding screen. Therefore, when the mode that the bending stress is reduced by thinning the OLED module is adopted, how to effectively stop the segmented glue from not debonding is considered.

Disclosure of Invention

The embodiment of the application provides a display panel, can solve the display panel among the prior art and distinguish the technical problem that the edge comes unstuck easily at buckling.

The embodiment of the application provides a display panel, which comprises at least one bending area, plane areas positioned on two sides of the bending area and a back plate body; the back plate support piece is arranged on one side surface of the back plate body; and a bonding layer disposed between the backplate body and the backplate support, the bonding layer being disposed only in the planar region; a groove is formed in one side surface, close to the back plate support piece, of the back plate body and/or one side surface, close to the back plate body, of the back plate support piece, the groove is located at the edge, close to the bending area, of the plane area, and the bonding layer fills the groove.

Optionally, in some embodiments of the present application, the adhesive layer includes a first adhesive layer disposed between the backplane body and the backplane support; and the second bonding layer is filled in the groove and is bonded with the first bonding layer, wherein one side edge of the second bonding layer is aligned with one side edge of the first bonding layer.

Optionally, in some embodiments of the present application, a ratio of a distance between the grooves on two sides of the same bending region to a width of the bending region is greater than 1.1 and less than 1.25.

Optionally, in some embodiments of the present application, a ratio of a width of the groove to a width of the bending region is greater than 0.16 and less than 0.25.

Optionally, in some embodiments of the present application, an opening area of the groove is smaller than a bottom area of the groove.

Optionally, in some embodiments of the present application, a side edge of the groove near the bending region is in a wave-shaped structure or a broken line structure.

Optionally, in some embodiments of the present application, the groove units are spaced apart from each other along the edge of the planar area close to the bending area, and the distance between two adjacent groove units is equal.

Optionally, in some embodiments of the present application, the opening shape of the groove unit is circular, rectangular, diamond, or trapezoidal.

Optionally, in some embodiments of the present application, the back plate support is provided with at least one stress releasing structure, the stress releasing structure is located in the bending region, when the display panel is bent, one side of the stress releasing structure, which is away from the back plate body, is in an expanded state, and one side of the stress releasing structure, which is close to the back plate body, is in a contracted state.

Optionally, in some embodiments of the present application, the stress relief structure includes a plurality of elongated through holes, and the elongated through holes are distributed in a staggered manner or in an array manner; the strip-shaped through hole comprises two long edges which are oppositely arranged, and the long edges are perpendicular to the bending direction of the back plate supporting piece.

The beneficial effects of this embodiment lie in, the tie coat in the district of buckling has been got rid of to a display panel of this embodiment, has reduced the thickness in display panel district of buckling, resists the shear stress when display panel buckles through increasing the thickness that the tie coat is close to the district one end of buckling, avoids the tie coat problem of coming unstuck to appear when buckling.

Drawings

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

fig. 2 is a schematic structural diagram of a display panel provided in an embodiment of the present application;

fig. 3 is a schematic structural diagram of a display panel provided in this embodiment of the present application after being bent;

FIG. 4 is a line graph of bond line rupture risk values versus groove width provided by an embodiment of the present application;

FIG. 5 is a side cross-sectional view of a backing plate body and a backing plate support provided by an embodiment of the present application;

FIG. 6 is a side cross-sectional view of a back plate body and back plate support member provided in accordance with another preferred embodiment of the present application;

FIG. 7 is a plan view of a backing plate support provided by an embodiment of the present application;

FIG. 8 is a plan view of a backing plate support provided in accordance with another preferred embodiment of the present application;

FIG. 9 is a plan view of a backing plate support provided in accordance with yet another preferred embodiment of the present application.

Description of reference numerals:

a display panel 1;

a back plate body 100; a back plate support 200;

a bonding layer 300; a panel body 400;

a bending zone 101; a planar region 102;

a recess 210; a first adhesive layer 310;

a second adhesive layer 320; a groove unit 211;

a stress relief structure 220; elongated through holes 221;

a first blind hole 222; and a second blind hole 223.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the 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 exemplary embodiments of the invention, are given by way of illustration and explanation only, and are not intended to limit the scope of the invention. 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. The details will be described below.

Examples

In this embodiment, the display panel 1 is mainly used for explaining the display panel 1 of the present invention, as shown in fig. 2 and fig. 3, the display panel 1 includes a back plate body 100, a back plate support 200, a bonding layer 300 and a panel body 400, the display panel 1 in this embodiment is a foldable display panel, the display panel 1 includes a light-emitting surface, the light-emitting surface is located on one side of the panel body 400 far away from the back plate body 100, and in a non-use state, the light-emitting surface of the display panel 1 is bent inward to achieve the purpose of folding the display panel 1, so that the display panel 1 is protected from being scratched by foreign objects, and the volume of the display panel 1 can be reduced.

Backplate body 100 and backplate support piece 200 bond through tie coat 300, and backplate support piece 200 is located backplate body 100 keeps away from one side of play plain noodles, and when display panel 1 buckled, backplate support piece 200's bending deformation is great, and its bending stress that receives is great, in order to promote backplate support piece 200's life, backplate support piece 200 in this embodiment is manganese-containing high strength sheet steel, and its monomer yield limit is not less than 1600Mpa, possesses good toughness and intensity.

According to the folding requirement of the display panel 1, the display panel 1 is divided into a bending area 101 and a plane area 102, and the plane area 102 is disposed on two sides of the bending area 101, in this embodiment, the display panel 1 is a single-bending panel, that is, the display panel 1 in this embodiment includes one bending area 101, in other preferred embodiments of the present invention, the display panel 1 may include N bending areas 101 (N is a natural number greater than 1), and the number of the corresponding plane areas 102 is N + 1. In order to reduce the bending stress of the display panel 1, the thickness of the bending region 101 is usually reduced by removing the adhesive layer 300 in the bending region 101, so that the bending stress of the display panel 1 in the bending region 101 is effectively reduced, and the removed adhesive layer 300 is symmetrical with respect to the bending center line of the bending region 101, thereby preventing the asymmetric adhesive layer 300 from affecting the bending of the display panel 1.

The adhesive layer 300 is an Optical Clear Adhesive (OCA) material, and has the technical effects of being colorless and transparent, high in light transmittance, high in adhesive strength, and small in curing shrinkage, and the adhesive layer 300 is located in the planar area 102 and used for bonding the backplane body 100 and the backplane support 200. When the display panel 1 is bent, since the adhesive layer 300 is designed to be broken, the side thereof close to the bending region 101 is easy to fall off under the action of tensile stress. In addition, since the bending direction of the display panel 1 in this embodiment is the direction in which the backplane body 100 is far away from the backplane support 200, so that the adhesive force between the adhesive layer 300 and the backplane support 200 decreases with the increase of the bending times and the bending time, in this embodiment, the groove 210 is formed on the backplane support 200 by etching through a half-etching process, which is intended to fill the adhesive layer 300, increase the contact area between the adhesive layer 300 and the backplane support 200, increase the adhesive force between the adhesive layer 300 and the backplane support 200, and increase the overall thickness of the adhesive layer 300 at the edge of the bending area 101, so as to effectively resist the shear stress applied to the adhesive layer 300 when the display panel 1 is bent, the shear stress is an in-plane force of the adhesive layer 300 per unit area of the shear section when the display panel 1 is bent, the shear section is a longitudinal section of the adhesive layer 300 between the backplane support 200 and the backplane body 100, and since the magnitude of the shear stress is negatively related to the area of the shear section, the larger the thickness of the adhesive layer 300 is, the smaller the shear stress applied to the adhesive layer 300 can be greater than the shear force applied to enable the adhesive layer 300 to be greater than the shear force or offset the problem of the problem that the display panel 300 that the edge of the display panel is not enough to be bent to cause the bubble to fall off when the backplane support 200, thereby effectively avoiding the display panel 200. In another preferred embodiment of the present application, a groove may be formed on the backplane body 100 by etching through a half etching process, and the groove 210 on the backplane support 200 may alternatively exist at the same time, and the purpose of the groove is also to increase the thickness of the adhesive layer 300, so as to effectively resist the shear stress generated when the display panel 1 is bent.

The grooves 210 are located at the edges of two sides of the bending area 101, and the ratio of the distance between the grooves 210 located at two sides of the same bending area 101 to the width of the bending area 101 is 1.1-1.25, so as to prevent the bonding layer 300 inside the grooves 210 from overflowing into the bending area 101 when stressed, because the width and the depth of the grooves 210 determine the size of the bonding layer 300 capable of resisting the shearing stress at the edge of the bending area 101, the narrower the width and the shallower the depth of the grooves 210 are, the smaller the shearing stress that the bonding layer 300 can resist is, the optimal values of the width and the depth of the grooves 210 can be known through mechanical simulation, according to analysis of test results, when the width N of the grooves 210 reaches 0.8 mm-1.6 mm, the stress value of the bonding layer 300 is smaller than a safety reference value (risk value 0.237 Mpa).

As shown in fig. 4, fig. 4 is data of a mechanical simulation test, and it can be known from the figure that when the width of the groove is between 1mm and 1.5mm, the stress value of the adhesive layer 300 will decrease rapidly until it is lower than the safety reference value, and when the width of the groove is greater than 1.7mm, the stress value of the adhesive layer 300 will tend to be stable, and the stress value will be stable at 0.15MPa to 0.2MPa.

Through multiple mechanical simulation tests, the result shows that when the width of the groove 210 is larger than 2mm, the stress value of the bonding layer 300 is stably lower than the safety reference value, and the risk is obviously reduced and tends to be stable; in order to avoid the reduction of the bending stiffness of the backplate support 200 caused by the excessive width N of the groove 210, in the embodiment, the width N of the groove 210 is 2mm to 4mm. The ratio of the width of the groove 210 to the width of the bending region 101 is greater than 0.16 and less than 0.25, and the depth of the groove 210 is 0.15-0.3 times of the thickness of the backplate support 200, so that the reduction of bending rigidity of the backplate support 200 caused by the overlarge depth of the groove 210 is avoided.

As shown in fig. 5 and 6, the adhesive layer 300 includes a first adhesive layer 310 and a second adhesive layer 320, wherein the first adhesive layer 310 is disposed between the backplate body 100 and the backplate support 200, and the second adhesive layer 320 is filled in the groove 210 by coating, planarization, or the like. When the second adhesive layer 320 completely fills the groove 210, the upper surface of the second adhesive layer 320 protrudes out of the groove 210 or is flush with the opening surface of the groove 210, so that the second adhesive layer 320 is adhered to the first adhesive layer 310, and the adhesion force between the first adhesive layer 310 and the second adhesive layer 320 is almost equal to the polymerization force inside the first adhesive layer 310 or the second adhesive layer 320, so that the first adhesive layer 310 and the second adhesive layer 320 are adhered to form an integral structure. First tie coat 310 is close to a side edge of kink zone 101 and a side edge that second tie coat 320 is close to kink zone 101 and aligns, in order to avoid display panel 1 when buckling, tie coat 300 overflows to kink zone 101's direction under the stress action of buckling, in the embodiment, the fracture interval of tie coat 300, the ratio of interval between the tie coat 300 that lies in kink zone 101 both sides promptly and kink zone 101's width is 1.1 ~ 1.25, still be equipped with certain buffer interval between tie coat 300 and the kink zone 101 promptly, avoid tie coat 300 atress too big emergence overflow to glue the problem.

In this embodiment, as shown in fig. 7, the groove 210 extends up and down to the edge of the backplate support 200 along the bending center line of the bending region 101, and the opening shape thereof is a long-strip rectangle, in another preferred embodiment of the present invention, as shown in fig. 8, one side edge of the groove 210 close to the bending region 101 is in a wave shape or a broken line shape, the length of the edge of the groove 210 close to one side of the bending region 101 is increased by the broken line or the wave line, the contact area between the edge of the bonding layer 300 and the backplate support 200 is increased, and the edge of the bonding layer 300 is prevented from being separated from the backplate body or the backplate support 200 during bending. In another preferred embodiment of the present invention, as shown in fig. 9, the groove units 211 are arranged at intervals, so as to effectively ensure the rigidity of the backplate support 200 on the premise of increasing the thickness of the adhesive layer 300, and the opening of the groove units 211 is trapezoidal, rhombic, and has a polygonal structure with an arc-shaped side facing the bending region 101.

In particular, in order to avoid the technical problem that the second adhesive layer 320 falls off due to the fact that the second adhesive layer 320 falls off when the second adhesive layer 320 falls off from the bottom of the groove 210 under the action of the bending stress, in this embodiment, the groove 210 is configured to have a structure with a narrow top and a wide bottom, that is, the opening area of the groove 210 is smaller than the bottom area of the groove 210, in another preferred embodiment of the present invention, the sidewall of the groove 210 may be recessed outward to form a "pot" shape, which also serves the technical purpose of limiting the relative position of the second adhesive layer 320 and the groove 210.

Because the bending deformation of the back plate supporting member 200 is relatively large when the display panel 1 is bent, in order to further reduce the bending stress of the back plate supporting member 200, in this embodiment, the stress releasing structure 220 is arranged at the position of the back plate supporting member 200 corresponding to the bending region 101, the stress releasing structure 220 is a hollow structure, and when the display panel 1 is bent, one end of the stress releasing structure 220 away from the back plate body 100 is in an expanded state, so that the tensile stress of the back plate supporting member 200 away from one side of the back plate body 100 is released; the end of the stress releasing structure 220 close to the backplate body 100 is in a contracted state, so as to release the contraction stress of the backplate support 200 close to one side of the backplate body 100.

Specifically, in the present embodiment, the stress releasing structure 220 is a plurality of strip-shaped through holes 221 distributed in an array, as shown in fig. 5 and 7, a long side direction of the stress releasing structure is perpendicular to a bending direction of the display panel 1, that is, a long side direction of the strip-shaped through hole 221 is parallel to an arrangement direction of the grooves 210 or extending directions of two ends of the groove. One end or both ends of the elongated through hole 221 are respectively disposed between the other two elongated through holes, so as to improve the uniformity of the stress releasing structure 220 and ensure that the stress applied to the back plate support 200 can be uniformly released. In another preferred embodiment of the present invention, the elongated through holes 221 may also be distributed in a staggered manner.

In another preferred embodiment of the present invention, the stress releasing structure 220 is a plurality of spaced blind holes, as shown in fig. 6, the blind holes include a first blind hole 222 and a second blind hole 223, the first blind hole 222 is located on a side surface of the backplate support 200 facing the backplate body 100, the second blind hole 223 is located on a side surface of the backplate support 200 away from the backplate body 100, and the first blind hole 222 and the second blind hole 223 are disposed in a staggered manner in a direction perpendicular to the backplate support 200, so as to ensure the rigidity of the backplate support 200 and avoid the technical problem of fracture during bending.

The foregoing detailed description is directed to a display panel provided in an embodiment of the present application, and specific examples are applied herein to illustrate the principles and implementations of the present application, and the above description of the embodiments is only provided to help understand 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 display panel comprises at least one bending area and plane areas positioned at two sides of the bending area, and is characterized by also comprising

A back plate body;

the back plate support piece is arranged on one side surface of the back plate body; and

a bonding layer disposed between the backplate body and the backplate support, the bonding layer being located only in the planar region;

a groove is formed in one side surface, close to the back plate support piece, of the back plate body and/or one side surface, close to the back plate body, of the back plate support piece, the groove is located at the edge, close to the bending area, of the plane area, and the bonding layer fills the groove.

2. The display panel according to claim 1,

the bonding layer comprises

The first bonding layer is arranged between the back plate body and the back plate support piece; and

and the second bonding layer is filled in the groove and is bonded with the first bonding layer, wherein one side edge of the second bonding layer is aligned with one side edge of the first bonding layer.

3. The display panel according to claim 2,

the ratio of the space between the grooves on two sides of the same bending area to the width of the bending area is more than 1.1 and less than 1.25.

4. The display panel according to claim 2,

the ratio of the width of the groove to the width of the bending area is more than 0.16 and less than 0.25.

5. The display panel according to claim 1,

the opening area of the groove is smaller than the bottom area of the groove.

6. The display panel according to claim 1,

one side edge of the groove close to the bending area is of a wavy structure or a broken line structure.

7. The display panel according to claim 1,

the groove comprises a plurality of groove units, the groove units are distributed at intervals along the edge of the plane area close to the bending area, and the distance between every two adjacent groove units is equal.

8. The display panel according to claim 1,

the opening of the groove unit is circular, rectangular, rhombic or trapezoidal.

9. The display panel according to claim 1,

the backboard support piece is provided with at least one stress release structure, the stress release structure is located in the bending area, when the display panel is bent, one side of the stress release structure, which is far away from the backboard body, is in an expansion state, and one side of the stress release structure, which is close to the backboard body, is in a contraction state.

10. The display panel according to claim 9,

the stress release structure comprises a plurality of strip-shaped through holes, and the strip-shaped through holes are distributed in a staggered manner or in an array manner;

the strip-shaped through hole comprises two long edges which are oppositely arranged, and the long edges are perpendicular to the bending direction of the back plate supporting piece.