CN216980565U

CN216980565U - Display device

Info

Publication number: CN216980565U
Application number: CN202220219525.4U
Authority: CN
Inventors: 卿太峰; 陆旭; 伏安; 王一飞
Original assignee: BOE Technology Group Co Ltd; Chengdu BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Chengdu BOE Optoelectronics Technology Co Ltd
Priority date: 2022-01-25
Filing date: 2022-01-25
Publication date: 2022-07-15
Anticipated expiration: 2032-01-25

Abstract

The utility model relates to the technical field of display, in particular to a display device which can reduce the risk of cracks of a back film. The display device includes: display substrate, notacoria and protective layer. The display substrate comprises a main body part, a bending part and a circuit board connecting part which are connected in sequence. The bending part is positioned at one end of the main body part, and the circuit board connecting part is positioned at the non-light-emitting side of the display substrate. The back film comprises a first sub back film and a second sub back film which are arranged at intervals, and the first sub back film is connected with the back surface of the main body part; the second sub-back film is located between the first sub-back film and the circuit board connecting part and connected with the circuit board connecting part. The protective layer is located the front of kink, and the protective layer includes the first end that is close to the main part and the second end that is close to circuit board connecting portion. And the thickness of the first sub-back film is less than or equal to that of the second sub-back film. The display device is used for image display.

Description

Display device

Technical Field

The utility model relates to the technical field of display, in particular to a display device.

Background

Organic Light Emitting Diodes (OLEDs), which are current type Light Emitting devices, are increasingly used in high performance display substrates due to their characteristics of self-luminescence, fast response, wide viewing angle, and being fabricated on flexible substrates.

Currently, in the related art, a concept of a full-screen display is presented, that is, an image collector is disposed on a non-light-emitting side of a display substrate to improve a screen ratio.

SUMMERY OF THE UTILITY MODEL

It is an object of embodiments of the present invention to provide a display device for reducing the risk of cracking of a backing film. In order to achieve the above purpose, the embodiment of the present invention provides the following technical solutions:

the embodiment of the utility model provides a display module, and the display device comprises: display substrate, notacoria and protective layer. The display substrate comprises a main body part, a bending part and a circuit board connecting part which are sequentially connected; the bending part is positioned at one end of the main body part, and the circuit board connecting part is positioned at the non-light-emitting side of the display substrate. The back film comprises a first sub back film and a second sub back film which are arranged at intervals; the first sub-back film is connected with the back of the main body part and at least covers the main body part; the second sub-back film is positioned between the first sub-back film and the circuit board connecting part, is connected with the circuit board connecting part and at least covers the circuit board connecting part. The protective layer is positioned on the front surface of the bending part; the protective layer comprises a first end close to the main body part and a second end close to the circuit board connecting part; in a direction perpendicular to the plane of the main body portion, the first end is partially overlapped with the first sub-back film, and the second end is partially overlapped with the second sub-back film. Wherein, the thickness of the first sub-back film is less than or equal to that of the second sub-back film.

The display device provided by the embodiment of the utility model comprises: display substrate, notacoria and protective layer. Through dividing the structure of display substrate, divide it into main part, kink and the circuit board connecting portion that connect gradually, through making the kink buckle, can make circuit board connecting portion and the circuit board of binding with it buckle to display substrate's non-light-emitting side, reduce display device's frame size to increase display device's screen and account for the ratio.

Through set up the notacoria between main part and circuit board connecting portion to set up first sub-notacoria in the notacoria and the sub-notacoria interval of second, make and have the clearance between first sub-notacoria and the sub-notacoria of second, can make the kink have great radian of buckling like this, prevent that the kink from breaking because the great stress that leads to receiving is great because of great deformation.

The protective layer is arranged on the front face of the bending portion, the protective layer can be used for protecting the bending portion, and the risk that the one face, protruding from the bending portion, of the bending portion is broken due to the fact that the tensile stress is large is reduced. In addition, the first end of the protective layer is partially overlapped with the first sub-back film, the second end of the protective layer is partially overlapped with the second sub-back film, the overlapped area can be protected, and the risk of cracks or fractures at the joint of the main body part and the bending part and the joint of the bending part and the circuit board connecting part is reduced.

In addition, the thickness of the first sub-back film is set to be smaller than or equal to that of the second sub-back film, so that the second sub-back film can be ensured to have higher temperature and pressure bearing capacity, and the risk of fracture of the second sub-back film can be reduced when the binding operation is performed on the display substrate.

In some embodiments, the crystallinity of the first sub-backsheet is less than the crystallinity of the second sub-backsheet; the toughness of the second sub-back membrane is greater than that of the first sub-back membrane.

In some embodiments, the material of the first sub-backsheet comprises cyclic olefin polymer and the material of the second sub-backsheet comprises polyethylene terephthalate.

In some embodiments, the first sub-backsheet has a thickness ranging from 5 μm to 95 μm, and the second sub-backsheet has a thickness ranging from 10 μm to 95 μm.

In some embodiments, the first sub-backsheet comprises: a first side surface close to the bending part and a second side surface far away from the main body part; the joint of the first side surface and the second side surface is arranged in a chamfer way; and/or, the second sub-backsheet comprises: a third side surface close to the bending part and a fourth side surface far away from the circuit board connecting part; the junction of the third side and the fourth side is chamfered.

In some embodiments, the bending radius of the bending part is R, and a distance between a side surface of the first sub-backsheet near the bending part and a side surface of the second sub-backsheet near the bending part along the bending direction of the bending part is L; wherein L ═ (pi R +100) μm.

In some embodiments, the area of the second sub-backsheet is less than the area of the first sub-backsheet; the orthographic projection of the second sub-back membrane on the main body part is located in the orthographic projection range of the first sub-back membrane on the main body part.

In some embodiments, an overlapping area of the first end and the first sub-backsheet is smaller than an overlapping area of the second end and the second sub-backsheet.

In some embodiments, the display substrate includes a main display area and an auxiliary display area; the light transmittance of the part of the display substrate, which is positioned in the auxiliary display area, is greater than that of the part of the display substrate, which is positioned in the main display area; the second sub-back film is located in the main display area.

In some embodiments, the display device further comprises: the image collector is arranged on one side, away from the main body part, of the first sub-back film; the image collector is located in the auxiliary display area and is arranged in a staggered mode with the second sub-back membrane.

In some embodiments, the display device further comprises: the heat dissipation film is connected with the back surface of the first sub-back film; the heat dissipation film is provided with an opening, and the orthographic projection of the image collector on the heat dissipation film is positioned in the opening.

In some embodiments, the display device further comprises: a support sheet disposed between the heat dissipation film and the second sub-backsheet; the support sheet is configured to support the second sub-backsheet and the circuit board connection portion.

In some embodiments, the display device further comprises: the integrated circuit and the flexible circuit board are bound with the circuit board connecting part; the integrated circuit and the flexible circuit board are both positioned on one side of the circuit board connecting part, which is far away from the main body part, and the flexible circuit board is positioned on one side of the integrated circuit, which is far away from the bending part.

In some embodiments, the display device further comprises: the polaroid, the adhesive layer and the cover plate are arranged on the front surface of the main body part and are sequentially laminated; the cover plate covers the bonding layer, the polarizer, the display substrate and the back film.

In some embodiments, the first sub-backsheet comprises: the first adhesive layer is connected with the back surface of the main body part, and the first supporting layer is positioned on one side, far away from the main body part, of the first adhesive layer; the second sub-backsheet includes: the second adhesive layer is connected with the circuit board connecting part, and the second supporting layer is positioned on one side, far away from the circuit board connecting part, of the second adhesive layer.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in some embodiments of the present invention will be briefly described below, and it is apparent that the drawings in the following description are only drawings of some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings. Furthermore, the drawings in the following description may be regarded as schematic and are not intended to limit the actual size of the product to which embodiments of the utility model relate.

Fig. 1 is a structural diagram of a display device according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of the display device shown in FIG. 1 taken along the direction M-M';

FIG. 3 is another cross-sectional view of the display device of FIG. 1 taken along the direction M-M';

FIG. 4 is a cross-sectional view of the display device of FIG. 1 taken along the direction N-N';

fig. 5 is a structural diagram of a display device before bending processing according to an embodiment of the present invention;

fig. 6 is a structural diagram of a back film after a protective film is attached after the back film is manufactured according to an embodiment of the present invention;

FIG. 7 is a summary table of binding quality test results for a backing film of an embodiment of the utility model and an implementation;

FIG. 8 is a schematic process flow diagram for making a backing film in one implementation;

fig. 9 is a schematic process flow diagram for manufacturing a back film by splicing according to an embodiment of the present invention.

Reference numerals

1-display substrate 1 a-main body portion 1 b-bending portion

1 c-Circuit Board connection part 2-Back film 2 a-first sub-Back film

21 a-first adhesive layer 22 a-first supporting layer 2 b-second sub-back film

21 b-second glue layer 22 b-second support layer 3-protective layer

3 a-first end 3 b-second end 4-release film

5-protective film 6-first side 7-second side

8-third side 9-fourth side 10-image collector

11-radiating film 12-support sheet 13-integrated circuit

14-flexible circuit board 15-polarizer 16-adhesive layer

17-cover plate 100-display device

Detailed Description

For the convenience of understanding, the technical solutions provided by the embodiments of the present invention are described in detail below with reference to the accompanying drawings. It is obvious that the described embodiments are only some, not all embodiments of the proposed solution. All other embodiments obtained by a person skilled in the art based on the embodiments of the present invention without any creative work belong to the protection scope of the embodiments of the present invention.

In the following, the terms "first", "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of the present invention, "a plurality" means two or more unless otherwise specified.

The terms "comprising" and "including" are to be interpreted in an open, inclusive sense, i.e., as "including, but not limited to". In the description herein, the terms "one embodiment," "some embodiments," "an example embodiment," "an example" or "some examples" or the like are intended to indicate that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. The schematic representations of the above terms are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics may be included in any suitable manner in any one or more embodiments or examples.

"A and/or B" includes the following three combinations: a alone, B alone, and a combination of A and B.

The use of "for" or "configured to" herein means open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

In describing some embodiments, expressions of "coupled" and "connected," along with their derivatives, may be used. For example, the term "connected" may be used in describing some embodiments to indicate that two or more elements are in direct physical or electrical contact with each other. As another example, some embodiments may be described using the term "coupled" to indicate that two or more elements are in direct physical or electrical contact. The term "coupled," however, may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. The embodiments disclosed herein are not necessarily limited to the contents herein.

Example embodiments are described herein with reference to cross-sectional and/or plan views as idealized example figures. In the drawings, the thickness of regions are exaggerated for clarity. Variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, example embodiments should not be construed as limited to the shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of the exemplary embodiments.

At present, the non-light-emitting side of the display substrate is usually provided with a back film. After the image collector is arranged on the non-light-emitting side of the display substrate, the image collector is positioned on one side of the back film, which is far away from the display substrate. Therefore, external light rays sequentially penetrate through the display substrate and the back film to be incident to the image collector, and the image collector works. In order to ensure the normal work of the image collector, the back membrane is thin, so that when the binding operation is carried out on the display substrate, the temperature and the pressure during the binding are transmitted to the back membrane, and the back membrane is cracked.

Referring to fig. 1, an embodiment of the utility model provides a display device 100.

In some embodiments, referring to fig. 2 to 4, the display device 100 includes: a display substrate 1, a back film 2 and a protective layer 3.

In some examples, please refer to fig. 2 to 4, which show a substrate 1 including a main body portion 1a, a bending portion 1b and a circuit board connecting portion 1c connected in sequence. The bending portion 1b is located at one end of the main body portion 1a, and the circuit board connecting portion 1c is located at the non-light-emitting side of the display substrate 1.

Illustratively, the thickness of the display substrate 1 may range from 38 μm to 42 μm. For example, the thickness of the display substrate 1 may be 38 μm, 40 μm, 42 μm.

Illustratively, the display substrate 1 may include a plurality of pixel circuits and a plurality of light emitting devices. The plurality of pixel circuits may be electrically connected to the plurality of light emitting devices in a one-to-one correspondence, for example, and each pixel circuit may provide a driving signal to the corresponding light emitting device to drive the light emitting device to emit light.

Of course, there may be other electrical connection methods between the pixel circuit and the light emitting device, and the present invention is not limited thereto.

For example, the Light Emitting device may include an OLED (Organic Light Emitting Diode), a QLED (Quantum Dot Light Emitting Diode), and the like.

It will be appreciated that the display substrate 1 has a light-exiting side and a non-light-exiting side. The light emitting side refers to a side from which light emitted by the light emitting device exits, that is, a side of the display substrate 1 displaying a picture. The non-light-emitting side refers to a side of the display substrate 1 opposite to the light-emitting side.

Illustratively, the display substrate 1 may further include a plurality of signal lines, each of which may be electrically connected to at least two of the pixel circuits to provide a desired electrical signal to the corresponding pixel circuit.

For example, the plurality of pixel circuits and the plurality of light emitting devices may be located in the main body portion 1a, and a portion of each signal line may be located in the main body portion 1a, a portion thereof may be located in the bent portion 1b, and another portion thereof may be located in the circuit board connection portion 1 c.

For example, the circuit board connection part 1c may be bound to a circuit board to receive various electrical signals provided from the circuit board. The various signals may include, for example, electrical signals required for the pixel circuit, including, for example, data signals. The circuit board includes, for example, a flexible circuit board.

After the circuit board is bound with the circuit board connecting part 1c, the circuit board and the signal line are electrically connected. At this time, the electrical signal provided by the circuit board can be transmitted to the pixel circuit sequentially through the portion of the signal line located at the circuit board connecting portion 1c, the portion located at the bending portion 1b, and the portion located at the main body portion 1 a.

Illustratively, the bent portion 1b is located at one end of the main body portion 1a in the direction in which the signal line extends.

Illustratively, the bent portion 1b is processed by a bending process. For example, referring to fig. 5, before the bending portion 1b is subjected to the bending process, the display substrate 1 is entirely flat, that is, the main body portion 1a, the bending portion 1b and the circuit connecting portion 1c are located on the same plane. Referring to fig. 2 to 4, after the bending portion 1b is processed by the bending process, the whole bending portion 1b is arc-shaped, and one end of the bending portion 1b close to the circuit board connecting portion 1c is bent toward the non-light-emitting side of the display substrate 1, so that the circuit board connecting portion 1c is bent to the non-light-emitting side of the display substrate 1. Accordingly, other components bound to the circuit board connection portion 1c are also located on the non-light-emitting side of the display substrate 1. For example, the other components include an integrated circuit and a flexible circuit board, and for the integrated circuit and the flexible circuit board, reference may be made to the following description, which is not described herein again.

It is understood that the display device 100 further includes a frame, and the display substrate 1 is disposed in the frame to protect the display substrate 1 by the frame. After the bending portion 1b is bent and the circuit board connecting portion 1c is disposed on the non-light-emitting side of the display substrate 1, the frame size of the display device 100 can be effectively reduced, so that the display device 100 is convenient for implementing a narrow frame design. In addition, the area ratio of the main body 1a in the entire display device 100 can be increased on the plane of the main body 1a, thereby increasing the screen ratio of the display device 100.

In some examples, referring to fig. 2 to 4, the back film 2 includes a first sub back film 2a and a second sub back film 2b which are arranged at intervals. The first sub-backing film 2a is connected to the back surface of the main body portion 1a, and covers at least the main body portion 1 a. The second sub-back film 2b is located between the first sub-back film 2a and the circuit board connection portion 1c, is connected to the circuit board connection portion 1c, and covers at least the circuit board connection portion 1 c.

Illustratively, the back film 2 may support the display panel 1. For example, the first sub back film 2a may support the main body portion 1a, and the second sub back film 2b may support the circuit board connection portion 1 c.

Furthermore, in case the display substrate 1 is a flexible display substrate, the back film 2 may also protect the flexible display substrate from scratches and/or contamination.

Illustratively, the first sub-backsheet 2a and the second sub-backsheet 2b are spaced apart, meaning that there is a gap between the first sub-backsheet 2a and the second sub-backsheet 2b, which are not in direct contact. With such an arrangement, a certain distance is formed between the end of the bending portion 1b connected to the main body portion 1a and the end of the bending portion connected to the circuit board connecting portion 1c, so that the bending radian of the bending portion 1b is large, and the bending portion 1b is prevented from being broken due to large stress on the bending portion 1b caused by a small bending radian.

Illustratively, the back surface of the main body portion 1a refers to a surface of the main body portion 1a on the non-light-emitting side of the display substrate 1. That is, the first sub-backsheet 2a is located on the non-light-emitting side of the main body portion 1a, and both are in contact with each other.

Illustratively, the covering of at least the main body portion 1a by the first sub-backsheet 2a includes: the first sub-backing film 2a covers only the main body portion 1a, and the area of the first sub-backing film 2a is equal to that of the main body portion 1 a; alternatively, the first sub back film 2a covers the main body portion 1a and other components, and the area of the first sub back film 2a is larger than that of the main body portion 1 a. The other member may be, for example, a bent portion 1 b.

Exemplarily, the covering of at least the circuit board connection portion 1c by the second sub-back film 2b includes: the second sub-back film 2b covers only the circuit board connection part 1c, that is, the area of the second sub-back film 2b is equal to the area of the circuit board connection part 1 c; alternatively, the second sub back film 2b covers the circuit board connection portion 1c and other components, i.e., the area of the second sub back film 2b is larger than the area of the circuit board connection portion 1 c. The other member may be, for example, a bent portion 1 b.

In some examples, please refer to fig. 2 to 4, the protection layer 3 is located on a front surface of the bending portion 1 b. The protective layer 3 includes a first end 3a near the main body portion 1a and a second end 3b near the circuit board connection portion 1 c. The first end 3a and the first sub-backsheet 2a partially overlap, and the second end 3b and the second sub-backsheet 2b partially overlap, in a direction perpendicular to the plane of the main body portion 1 a.

Illustratively, before the bent portion 1b is subjected to the bending process, the front surface of the bent portion 1b is a side surface of the bent portion 3 on the light emitting side of the display substrate 1. After the bent portion 1b is subjected to the bending process, the front surface of the bent portion 1b is a side surface of the bent portion 1b protruding. That is, the protection layer 3 is located on the surface of the bent portion 1b on the side where it protrudes.

It should be noted that the protective layer 3 is bendable, and the material thereof has good toughness, so that the protective layer 3 can be largely deformed.

Before the bending process is performed on the bent portion 1b, the protective layer 3 may be disposed on the front surface of the bent portion 1b, and then the bending process may be performed on the bent portion 1 b. Thus, when the bent portion 1b is bent, the protective layer 3 protects the bent portion 1b, and the risk of the breakage of the convex surface of the bent portion 1b due to a large tensile stress is reduced.

For example, referring to fig. 2 to 5, the first end 3a of the protection layer 3 partially overlaps the first sub back film 2a, and the second end 3b partially overlaps the second sub back film 2b, and the first end 3a and the second end 3b of the protection layer 3 can be used to respectively protect the corresponding overlapping areas, so as to reduce the risk of cracks or fractures at the joint of the main body portion 1a and the bending portion 1b, and at the joint of the bending portion 1b and the circuit board connecting portion 1 c.

Illustratively, referring to fig. 2, the overlapping area S1 of the first end 3a and the first sub-backsheet 2a is smaller than the overlapping area S2 of the second end 3b and the second sub-backsheet 2 b.

By way of example, this can further enhance the protective effect on the joint of the bent portion 1b and the circuit board connecting portion 1c, further reducing the risk of cracking or breaking at the joint of the bent portion 1b and the circuit board connecting portion 1 c. Also, referring to fig. 2, the second end 3b of the protection layer 3 covers a portion of the second sub back film 2b with a larger area, so that the second sub back film 2b can be protected by the protection layer 3, and the second sub back film 2b is prevented from being broken when being subjected to a stress in a direction perpendicular to the second sub back film 2 b.

Optionally, the protection layer 3 includes a surface far away from the bending portion 1b, the second end 3b of the protection layer 3 has a side surface, the surface is connected with the side surface, and the side surface is further connected with the circuit board connecting portion 1 c. The included angle between the side face and the plane where the circuit board connecting portion 1c is located is small, that is, the slope of the side face is gentle. This may cause the thickness of the second end 3b of the protection layer 3 to increase or decrease relatively slowly, which is beneficial for further protecting the second sub-back film 2 b.

For example, the thickness of the first sub-back film 2a is set to be smaller than that of the second sub-back film 2b, so that the thickness of the display device 100 can be reduced under the effect of ensuring the main body of the first sub-back film 2a and protecting the flexible substrate of the main body 1a from being scratched and/or contaminated, which is not only beneficial to the light and thin design of the display device 100, but also beneficial to leaving more space for the whole machine. Moreover, when the binding operation is performed on the display substrate 1, since the thickness of the second sub back film 2b is large, the bearing capacity of the second sub back film 2b to temperature and pressure can be increased, and after the temperature and pressure of the binding operation are transmitted to the second sub back film 2b, the risk that the second sub back film 2b is broken can be reduced.

In some examples, referring to fig. 6, one side of the back film 2 is provided with a release film 4, and the other side of the back film 2 is attached with a protective film 5. The protective film 5 is used to protect the back film 2 (i.e., the first sub-back film 2a and the second sub-back film 2b) when the display substrate 1 is transferred between the processes.

In some examples, referring to fig. 6, before assembling the back film 2 and the display substrate 1, the release film 4 is removed, and then the back film 2 is assembled with the display substrate 1. After that, the protective film 5 needs to be removed by the relevant equipment in order to attach other components on the first sub-backing film 2a and the second sub-backing film 2b later.

Exemplarily, the thickness of the first sub-back film 2a is made to be equal to the thickness of the second sub-back film 2b by increasing the thickness of the first sub-back film, so that the risk of fracture of the second sub-back film can be reduced, and the protective film 5 attached to the first sub-back film and the second sub-back film can be ensured to be relatively flat, so that when the protective film 5 is removed by using related equipment, the removal process can be ensured to be relatively stable, the condition that the related equipment is stopped is avoided, and the protective film 5 can be removed quickly.

In some embodiments, the thickness of the first sub-backing film 2a ranges from 5 μm to 95 μm, and the thickness of the second sub-backing film 2b ranges from 10 μm to 95 μm.

Illustratively, the thickness of the first sub-back film 2a may be 5 μm, 30 μm, 75 μm, 95 μm, and the like. The thickness of the second sub back film 2b may be 10 μm, 30 μm, 88 μm, 95 μm, or the like.

It is understood that the thickness of the first sub-backsheet 2a and the thickness of the second sub-backsheet 2b may be any value in the above thickness range, but it is necessary to ensure that the thickness of the first sub-backsheet 2a is equal to or less than the thickness of the second sub-backsheet 2 b.

Therefore, in the display device 100 according to the embodiment of the present invention, the structure of the display substrate 1 is divided into the main body portion 1a, the bent portion 1b, and the circuit board connection portion 1c, which are sequentially connected, and the bent portion 1b is bent, so that the circuit board connection portion 1c and the circuit board bound thereto can be bent to the non-light-emitting side of the display substrate 1, thereby reducing the frame size of the display device 100 and increasing the screen occupation ratio of the display device 100.

Through set up notacoria 2 between main part 1a and circuit board connecting portion 1c to first sub notacoria 2a in notacoria 2 and second sub notacoria 2b interval sets up, makes and has the clearance between first sub notacoria 2a and the second sub notacoria 2b, can make kink 1b have great radian of buckling like this, prevents that kink 1b from breaking because the stress that great deformation leads to receiving is great.

By arranging the protective layer 3 on the front surface of the bent portion 1b, the bent portion 1b can be protected by the protective layer 3, and the risk that the convex surface of the bent portion 1b is broken due to large tensile stress is reduced. Further, by partially overlapping the first end 3a of the protective layer 3 with the first sub back film 2a and partially overlapping the second end 3b with the second sub back film 2b, the region where the two overlap can be protected, thereby reducing the risk of cracks or fractures at the joint between the main body portion 1a and the bent portion 1b and at the joint between the bent portion 1b and the circuit board connection portion 1 c.

Moreover, the thickness of the first sub-back film 2a is set to be less than or equal to the thickness of the second sub-back film 2b, so that the second sub-back film 2b can be ensured to have higher temperature and pressure bearing capacity, and the risk of the second sub-back film 2b breaking when the binding operation is performed on the display substrate 1 can be reduced.

In the related art, the material of the back film is PET (Polyethylene Terephthalate). However, the above PET has a high crystallinity, and after external light passes through the back film, a phase difference is generated due to the complex bending property of PET, and the phase difference enables the external light to form a plurality of wave crests and wave troughs.

In one implementation, the material of the back film is COP (cyclic Olefin Polymer) to reduce or avoid the occurrence of a situation that external light generates rainbow patterns after passing through the back film, and avoid affecting the working state of the image collector. However, the cycloolefin polymer has poor toughness, so that the back film is easy to crack, and the product yield is reduced.

In some examples, please refer to fig. 2 to 4, wherein the crystallinity of the first sub-back film 2a is smaller than the crystallinity of the second sub-back film 2 b. The toughness of the second sub-back film 2b is greater than that of the first sub-back film 2 a.

Illustratively, the crystallinity is a parameter used to indicate the proportion of crystalline domains in the polymer, and a higher crystallinity of a material indicates a higher proportion of crystalline domains in the polymer. Toughness is the ability of a material to absorb energy during plastic deformation and fracture, and the better the toughness of a material, the less likely a brittle fracture will occur.

Illustratively, the present invention sets the crystallinity of the first sub back film 2a to be smaller than the crystallinity of the second sub back film 2b, and can make the proportion occupied by the crystalline region in the first sub back film 2a smaller than the proportion occupied by the crystalline region in the second sub back film 2 b. Like this, after external light passed main part 1a and first sub-notacoria 2a in proper order, the wavelength of external light is comparatively steady, can reduce because the phase difference that the compound zigzag characteristic of first sub-notacoria 2a material produced, has just also reduced external light and has formed the condition that a plurality of crests and troughs and a plurality of crests were superposed together, can reduce effectively and avoid the production of rainbow line even.

It is understood that the binding between the circuit board connection part 1c and the circuit board is performed under the conditions of high temperature and high pressure. The high temperature in the bonding environment and the pressure applied to the circuit board connection portion 1c are also transmitted to the second sub-back film 2 b.

Illustratively, the present invention sets the toughness of the second sub-backsheet 2b to be greater than that of the first sub-backsheet 2a, so that the material of the second sub-backsheet 2b can have a greater ability to absorb energy during plastic deformation and rupture than the material of the first sub-backsheet 2 a. Thus, when the circuit board connecting portion 1c is bonded to the circuit board, the second sub-back film 2b can withstand higher temperature and pressure than the first sub-back film 2a, so that the risk of the second sub-back film 2b breaking can be reduced. Compared with the above implementation manner, the yield of the product (i.e., the display device 100) can be effectively improved.

In some embodiments, the material of the first sub-backsheet 2a comprises a cyclic olefin polymer and the material of the second sub-backsheet 2b comprises polyethylene terephthalate.

It is understood that the crystallinity of the cyclic olefin polymer is less than that of polyethylene terephthalate, and the cyclic olefin polymer has less influence on light. Therefore, after the external light passes through the first sub-back film 2a formed by the cyclic olefin polymer, the wavelength of the external light is stable, the phase difference generated by the complex bending characteristic of the material of the first sub-back film 2a is reduced, the condition that a plurality of wave crests and wave troughs and a plurality of wave crests formed by the external light are superposed together is reduced, and the generation of rainbow patterns is effectively reduced or even avoided.

The toughness of the polyethylene terephthalate is greater than that of the cycloolefin polymer, and the ability of the second sub-film 2b formed of the polyethylene terephthalate to absorb energy during plastic deformation and rupture is greater than that of the first sub-film 2a formed of the cycloolefin polymer to absorb energy during plastic deformation and rupture. Therefore, when the circuit board connecting portion 1c is bonded to the circuit board, the second sub-back film 2b can bear higher temperature and higher pressure, so that the risk of breaking the second sub-back film 2b is reduced, and the yield of the display device 100 is improved.

Illustratively, the tensile strength of the polyethylene terephthalate is 138N/cm²The tensile strength of the cycloolefin polymer is only 40N/cm². The first sub-backsheet 2a formed of a cycloolefin polymer is brittle and has poor toughness. The second sub-back film 2b formed of polyethylene terephthalate is easily broken when the circuit board connection part 1c is bonded to the circuit board.

Referring to fig. 7, "one implementation" in fig. 7 means that the entirety of the back film 2 is formed using a cyclic olefin polymer. In the binding verification of a chip (such as an integrated circuit) and in the binding verification test of a circuit board, the chip and the circuit board are bound by adopting three different temperature conditions and pressure conditions respectively, and the corresponding serial numbers are 2-1, 2-2 and 2-3. Under each temperature condition and pressure condition, the lighting result of the display substrate after 18 bonding chips and circuit boards is counted, and in the lighting result statistics, NG (Not Good) proportions are respectively as follows: 61%, 67%, the total NG ratio under three different temperature and pressure conditions being 63%. Under two different temperature conditions and pressure conditions, in the statistics of the quality engineer check (spot inspection is performed on the normal display substrate in the lighting result), the NG ratios are respectively as follows: 100%, 0%, and a total NG ratio of 63% under two different temperature and pressure conditions. Here, the non-display in NG means that the display substrate does not display an image, and the non-display means that the display substrate displays an image abnormality.

The "present invention" in fig. 7 means that, among the back films, the first sub back film is formed using a cycloolefin polymer, and the second sub back film is formed using polyethylene terephthalate. In the chip binding verification and the circuit board binding verification test, the chip and the circuit board are bound respectively under three temperature conditions and pressure conditions which are the same as the implementation modes, and the corresponding serial numbers are 3-1, 3-2 and 3-3. Under each temperature condition and pressure condition, counting the lighting results of the display substrates with 25 bound chips and circuit boards, wherein in the counting of the lighting results, the NG proportions are respectively as follows: 44%, 0%, 96%, the total NG ratio under three different temperature conditions and pressure conditions being 47%. Under a temperature condition and a pressure condition, in the statistics of the result of the quality engineer inspection (normal display substrate sampling inspection in the lighting result), the proportion of NG is as follows: 17%, the total NG proportion is 17%.

From the above, the total NG ratio in the present invention is smaller than that in the above-described one implementation. The utility model adopts the first sub-back film formed by the cycloolefin polymer and the second sub-back film formed by the polyethylene terephthalate to form the back film by splicing, and can effectively improve the yield of the display device 100.

In some embodiments, referring to fig. 3 and 6, the first sub-backsheet 2a includes: a first adhesive layer 21a connected with the back surface of the main body part 1a, and a first supporting layer 22a positioned on the side of the first adhesive layer 21a far away from the main body part 1 a. The second sub-backsheet 2b includes: a second adhesive layer 21b connected to the circuit board connecting portion 1c, and a second supporting layer 22b located on a side of the second adhesive layer 21b away from the circuit board connecting portion 1 c.

Exemplarily, the first adhesive layer 21a is used for bonding the main body portion 1a and the first support layer 22 a; the second adhesive layer 21b is used to bond the circuit board connection part 1c and the second support layer 22 b.

Illustratively, the first adhesive layer 21a and the second adhesive layer 21b may both be pressure-sensitive adhesives.

Exemplarily, in conjunction with fig. 3 and 6, the first support layer 22a in the first sub back film 2a is used for supporting the main body portion 1a and the partially folded portion 1b in contact therewith, and the material of the first support layer 22a may be, for example, a cyclic olefin polymer. The display substrate 1 may be, for example, a flexible display substrate, the material of the base of the display substrate 1 is generally PI (Polyimide), the Polyimide material is soft, and the first supporting layer 22a is hard, so that the flexible display substrate can be supported.

Illustratively, the second support layer 22b in the second sub-backing film 2b is used to support the circuit board connection portion 1c and the partially bent portion 1b in contact therewith. The material of the second support layer 22b may be, for example, polyethylene terephthalate. The display substrate 1 may be, for example, a flexible display substrate, the material of the base of the display substrate 1 is generally PI (Polyimide), the Polyimide material is soft, and the second support layer 22b is hard, so that the flexible display substrate can be supported.

For example, the thickness of the first support layer 22a may be 50 μm, and the thickness of the first glue layer 21a may be 25 μm. Thus, the thickness of the first sub-back film 2a is 50 μm +25 μm — 75 μm. The thickness of the second support layer 22b may be 75 μm, and the thickness of the second glue layer 21b may be 13 μm. Thus, the thickness of the second sub back film 2b is 88 μm, which is 75 μm +13 μm. The thickness of the first sub-back film 2a is smaller than that of the second sub-back film 2b, so that the overall thickness of the display device 100 can be reduced under the effects of ensuring that the first sub-back film 2a supports the display substrate 1 and protecting the flexible substrate of the flexible display substrate from being scratched and/or contaminated.

In some embodiments, referring to fig. 2 and 3, the first sub-backsheet 2a includes: a first side surface 6 close to the bending part 1b and a second side surface 7 far away from the main body part 1 a; the junction of the first side 6 and the second side 7 is chamfered. And/or, the second sub-backsheet 2b includes: a third side 8 close to the bending part 1b and a fourth side 9 far from the circuit board connecting part 1 c; the junction of the third side 8 and the fourth side 9 is chamfered.

For example, "chamfer" refers to a process of cutting a corner of a workpiece to a bevel, including straight chamfer and round chamfer. By arranging the chamfer, the phenomenon of stress concentration can be reduced, and the strength of the material is enhanced.

Illustratively, the junction between the first side surface 6 and the second side surface 7 is a chamfer, and the chamfer may be a straight chamfer as shown in fig. 2 or a round chamfer as shown in fig. 3.

For example, in the case where the chamfer at the junction of the first side 6 and the second side 7 is a straight chamfer, the first side 6 and the second side 7 may both be planar, e.g., vertically disposed, and connected by a bevel. In the case where the chamfer at the joint of the first side surface 6 and the second side surface 7 is a round chamfer, the first side surface 6 may be, for example, a curved surface, and the second side surface 7 may be a flat surface, which are directly connected.

By adopting the arrangement mode, the stress at the joint of the first side surface 6 and the second side surface 7 can be reduced, the stress concentration phenomenon at the joint is avoided, the fixing strength between the first side surface 6 and the second side surface 7 is favorably enhanced, and the strength of the first sub-back film 2a for supporting the main body part 1a is also favorably ensured to be large enough.

Illustratively, the junction between the third side 8 and the fourth side 9 is a chamfer, and the chamfer may be a straight chamfer as shown in fig. 2 or a round chamfer as shown in fig. 3.

For example, in the case where the chamfer at the junction of the third side 8 and the fourth side 9 is a straight chamfer, the third side 8 and the fourth side 9 may both be flat, e.g., vertically disposed, and connected by a bevel. In the case that the chamfer at the junction of the third side 8 and the fourth side 9 is a rounded chamfer, the third side 8 may be a cambered surface, and the fourth side 9 may be a flat surface, which are directly connected.

By adopting the arrangement mode, the stress at the joint between the third side surface 8 and the fourth side surface 9 can be reduced, the phenomenon of stress concentration at the joint is avoided, the fixing strength between the third side surface 8 and the fourth side surface 9 is favorably enhanced, and the strength of the second sub-back film 2b for supporting the circuit board connecting part 1c is also favorably ensured to be large enough.

In some embodiments, referring to fig. 3 and 5, the bending radius of the bent portion 1b is R, and the distance between the surface of the first sub-backsheet 2a on the side close to the bent portion 1b and the surface of the second sub-backsheet 2b on the side close to the bent portion 1b along the bending direction of the bent portion 1b is L; wherein L ═ (pi R +100) μm.

It can be understood that, after the bending processing is performed on the bent portion 1b, one side surface of the first sub back film 2a close to the bent portion 1b is the first side surface 6; the surface of the second sub-back film 2b near the bent portion 1b is the third side 8. The above-mentioned "bending direction along the bent portion 1 b" means a direction along the back surface of the bent portion 1b and directed from one end of the bent portion 1b to the other end, and the direction of the direction is arc-shaped.

For example, referring to fig. 5, the distance L is a distance between the first side 6 and the third side 8 before the bending portion 1b is bent. The value of the above-mentioned pitch L may be kept constant after the bending of the bent portion 1 b.

For example, after the structure shown in fig. 5 is manufactured, the bent portion 1b of the display substrate 1 may be bent to position the circuit board connection portion 1c on the non-light-emitting side of the display substrate 1, where the shape of the bent portion 1b may be an arc, and the bending radius thereof is R. The length of the distance L is set to (pi R +100) μm, so that a proper distance between the first sub-back film 2a and the second sub-back film 2b after bending can be ensured, the bending quality can be ensured, stress concentration caused by large deformation of the bending part 1b during bending can be avoided, and the risk of breakage of the bending part 1b can be reduced.

For example, the bent portion 1b may have a circular arc shape after being bent. The deformation of each part in the arc is relatively uniform, so that the stress applied to each part of the bending part 1b during bending can be dispersed, and the condition that the bending part 1b is broken due to stress concentration during bending can be effectively avoided.

In some embodiments, referring to fig. 4 and 6, the area of the second sub-backsheet 2b is smaller than the area of the first sub-backsheet 2 a. The orthographic projection of the second sub-back film 2b on the main body part 1a is positioned in the orthographic projection range of the first sub-back film 2a on the main body part 1 a.

For example, the first sub back film 2a may cover the entire main body portion 1a, and the second sub back film 2b may cover a part of the main body portion 1a, in a direction perpendicular to the plane of the main body portion 1a, wherein the part of the main body portion 1a not covered by the second sub back film 2b may be used to dispose other components (such as a battery, etc.) of the display device 100.

By setting the area of the second sub back film 2b smaller than the area of the first sub back film 2a and setting the orthographic projection of the second sub back film 2b on the main body portion 1a to be within the orthographic projection range of the first sub back film 2a on the main body portion 1a, the space of the display device 100 for setting other components can be increased.

In addition, in the process of passing through the display substrate 1, the external light can pass through the part of the main body portion 1a not covered by the second sub back film 2b and the part of the first sub back film 2a not covered by the second sub back film 2b from the light-emitting side of the display substrate 1, so that the external light can be effectively prevented from entering the second sub back film 2b, and rainbow stripes are prevented from being generated.

In some embodiments, referring to fig. 1 and 4, the display substrate 1 includes a main display area a1 and an auxiliary display area a 2. The light transmittance of the portion of the display substrate 1 positioned in the auxiliary display region a2 is greater than that of the portion of the display substrate 1 positioned in the main display region a 1. The second sub-backsheet 2b is positioned in the main display area a 1.

In some examples, among the plurality of light emitting devices and the plurality of pixel circuits located in the main body portion 1a, a portion of the light emitting devices are located in the main display region a1, and another portion of the light emitting devices are located in the auxiliary display region a2, and both of the pixel circuits electrically connected to the light emitting devices located in the main display region a1 and the pixel circuits electrically connected to the light emitting devices located in the auxiliary display region a2 are located in the main display region a 1.

This makes it possible to make both the portion of the display substrate 1 located in the main display area a1 and the portion located in the auxiliary display area a2 usable for image display.

It is understood that the pixel circuit includes an opaque material, which has a blocking effect on the external light incident on the pixel circuit. According to the utility model, by arranging the pixel circuits in the main display area A1, the structure of the auxiliary display area A2 for blocking external light can be reduced, so that the external light can penetrate through the gap between any two adjacent light-emitting devices in the auxiliary display area A2 from one side of the display substrate 1 and be emitted from the other side of the display substrate 1, and the light transmittance of the part of the display substrate 1 in the auxiliary display area A2 is increased.

By disposing the second sub-backsheet 2b in the main display region a1, it is possible to prevent external light passing through the auxiliary display region a2 from entering the second sub-backsheet 2b to generate rainbow patterns.

In some embodiments, referring to fig. 4, the display device 100 further includes: and an image collector 10 disposed on the side of the first sub-back film 2a away from the main body 1 a. The image collector 10 is located in the auxiliary display area a2, and is disposed to be offset from the second sub-back film 2 b.

For example, the image collector 10 may be a camera or a fingerprint sensor.

For example, the external light may sequentially pass through the portion of the display substrate 1 located in the auxiliary display area a2 and the portion of the first sub-back film 2a located in the auxiliary display area a2, enter the image collector 10, be collected by the image collector 10, and be imaged.

Since the light transmittance of the portion of the display substrate 1 located in the auxiliary display area a2 is greater than that of the portion of the display substrate 1 located in the main display area a1, the loss of external light after passing through the portion of the display substrate 1 located in the auxiliary display area a2 is less, which is beneficial to ensuring the imaging effect of the image collector 10.

Moreover, the image collector 10 and the second sub-back film 2b are arranged in a staggered manner, so that interference and/or collision between the image collector 10 and the second sub-back film 2b can be avoided, and rainbow marks generated by external light collected by the image collector 10 can be avoided.

Illustratively, the display device 100 may be any product or component having a display function and an image capturing function, such as a mobile phone, a tablet computer, a notebook computer, a laptop computer, a personal computer, a display, a wearable device, and the like.

In some embodiments, referring to fig. 4, the display device 100 further includes: and a heat dissipation film 11 connected to the back surface of the first sub back film 2 a. The heat dissipation film 11 has an opening in which an orthographic projection of the image acquirer 10 on the heat dissipation film 11 is located.

Illustratively, the back surface of the first back film 6 is the surface of the first back film 6 on the side away from the display substrate 1. Therefore, the heat dissipation film 11 is located on the side of the first sub back film 2a away from the display substrate 1.

For example, the heat dissipation film 11 may be electrically connected to the first sub-back film 2a, and the heat dissipation film 11 is grounded, so that the heat dissipation film 11 may discharge static electricity on the first sub-back film 2 a. The heat dissipation film 11 also has a function of dissipating heat, and can dissipate heat generated by the display substrate 1.

Illustratively, the heat dissipation film 11 may include a metal material disposed in an entire layer.

It will be appreciated that the heat spreading film 11 is typically disposed in a single layer and is opaque to light. By arranging the opening in the heat dissipation film 11 and enabling the orthographic projection of the image collector 10 on the heat dissipation film 11 to be located in the opening, external light can be enabled to normally enter the image collector 10 without being blocked by the heat dissipation film 11 after passing through the first sub-back film 2a, and the image collector 10 can be guaranteed to normally work.

Illustratively, the opening in the heat dissipation film 11 may be slightly larger than the image pickup device 10 in a direction perpendicular to the plane of the main body portion 1a, so as to prevent the heat dissipation film 11 from colliding with the image pickup device 10.

Illustratively, the thickness of the heat dissipation film 11 may range from 18 μm to 32 μm. The thickness of the heat dissipation film 11 may be 18 μm, 25 μm, 32 μm, or the like, for example.

In some embodiments, referring to fig. 2-4, the display device 100 further comprises: a support sheet 12 disposed between the heat dissipation film 11 and the second sub-backsheet 2 b. The support sheet 12 is configured to support the second sub-backsheet 2b and the circuit board connection portion 1 c.

For example, after the second sub back film 2b is bent to the non-light-emitting side of the display substrate 1, the bent portion 1b is in a circular arc shape, and thus, a gap is formed between the first sub back film 2a and the second sub back film 2 b. By providing the support sheet 12 between the heat dissipation film 11 and the second sub-backsheet 2b, the gap between the first sub-backsheet 2a and the second sub-backsheet 2b can be filled, and the second sub-backsheet 2b and the circuit board connection portion 1c can be supported, preventing the first sub-backsheet 2a and/or the second sub-backsheet 2b from being loosened.

For example, in one display device 100, the sum of the thicknesses of the heat dissipation film 11 and the support sheet 12 may be a fixed value.

Illustratively, the support sheet 12 may be a double-sided tape having a certain thickness and elasticity.

Illustratively, the support sheet 12 may have a thickness in the range of 84 μm to 300 μm. The support sheet 12 may have a thickness of 84 μm, 200 μm, 300 μm, or the like, for example.

In some embodiments, referring to fig. 4, the display device 100 further includes: an integrated circuit 13 and a flexible circuit board 14 bound to the circuit board connection portion 1 c; the integrated circuit 13 and the flexible circuit board 14 are both located on the side of the circuit board connecting portion 1c away from the main body portion 1a, and the flexible circuit board 14 is located on the side of the integrated circuit 13 away from the bending portion 1 b.

Illustratively, the integrated circuit 13 may be used to provide the display signal to the display substrate 1, and the integrated circuit 13 may be a driving chip, for example. The flexible circuit board 14 may transmit various display signals or touch signals.

Illustratively, the flexible circuit board 14 may be a multilayer board, which may reduce the space occupied by the flexible circuit board 14 in the length direction of the display device 100 shown in fig. 1. For example, the length of the battery in the display device 100 can be made longer, so that the thickness of the battery can be made thinner, thereby reducing the overall thickness of the display device 100 and facilitating the light and thin design of the display device 100. Various electronic components, such as resistors, capacitors, etc., may also be disposed on the flexible circuit board 14.

The integrated circuit 13 and the flexible circuit board 14 are both located on the side of the circuit board connection portion 1c away from the main body portion 1a, so that the integrated circuit 13 and the flexible circuit board 14 do not interfere with the main body portion 1 a.

In some embodiments, referring to fig. 4, the display device 100 further includes: a polarizer 15, an adhesive layer 16, and a cover 17, which are provided on the front surface of the main body 1a and laminated in this order. The cover plate 17 covers the adhesive layer 16, the polarizer 15, the display substrate 1, and the back film 2.

Illustratively, the polarizer 15 is disposed on the front surface of the main body 1a (i.e., the light-emitting side of the display substrate 1), so as to reduce the light reflectivity of the light-emitting side surface of the display device 100 and improve the display contrast of the display device 100.

For example, the polarizer 15 may have a thickness ranging from 0.01mm to 0.12 mm. The thickness of the polarizer 15 may be, for example, 0.01mm, 0.07mm, 0.12mm, or the like.

Illustratively, an adhesive layer 16 is disposed between the polarizer 15 and the cover 17 for adhering the polarizer 15 and the cover 17.

For example, the material of the Adhesive layer 16 may be OCA (optical Clear Adhesive, special Adhesive for gluing transparent optical elements). The thickness of the adhesive layer 16 may range from 0.01mm to 0.15 mm. The thickness of the adhesive layer 16 may be, for example, 0.01mm, 0.08mm, 0.15mm, or the like

Illustratively, the cover plate 17 is disposed on a side of the adhesive layer 16 away from the display substrate 1, and the cover plate 17 has a larger area and covers the adhesive layer 16, the polarizer 15, the display substrate 1, the back film 2, and the like to protect the adhesive layer 16, the polarizer 15, the display substrate 1, the back film 2, and the like.

For example, the cover 17 may be made of glass, which has high light transmittance and high hardness, and may be protected by a member covered with the cover 17. The thickness of the cover 17 may range from 0.02mm to 1 mm. The thickness of the cover 17 may be, for example, 0.02mm, 0.5mm, 1mm, or the like.

Next, a process for manufacturing the back film 2 in the display device 100 according to the present invention will be described with reference to fig. 8 and 9.

In one implementation, the backing film 2 comprises the same support material, see fig. 8, for example the backing film 2 comprises polyethylene terephthalate (PET). The display area corresponds to the area where the main body portion 1a is located in fig. 5, the connection area corresponds to the area where the circuit board connection portion 1c is located in fig. 5, and the area between the display area and the connection area corresponds to the bending area 1b in fig. 5.

The whole layer of PET is attached to the release film 4' and the whole layer of pressure sensitive adhesive, and the portion of the polyethylene terephthalate material between the display area and the connection area is half-cut (half-cut lines are shown as a half-cut line a ' and a half-cut line B ' in fig. 8) to form a U-shaped groove, which corresponds to the area where the bending portion 1B of the display device 100 is located. Thereafter, a protective film 5 is covered over the PET layer to protect the cut PET layer.

In an embodiment of the utility model, see fig. 9, the backing film 2 comprises two different materials: cycloolefin polymer material (COP) and polyethylene terephthalate (PET). The display region shown in fig. 9 corresponds to the region where the main body portion 1a in fig. 5 is located, the non-display region corresponds to the region where the bent portion 1b and the circuit board connection portion 1c in fig. 5 are located, and the connection region corresponds to the region where the bent portion 1b in fig. 5 is located. The first adhesive layer 21a and the second adhesive layer 21b of the back film 2 are both pressure-sensitive adhesives

As shown in fig. 9 (1), the entire COP is attached to the release film 4 and the entire pressure-sensitive adhesive, and half-cut is performed at the boundary position between the display region and the non-display region in the COP material.

As in (2) in fig. 9, the COP of the corresponding non-display region after half-cutting and the pressure-sensitive adhesive are removed.

As in (3) of fig. 9, PET and pressure sensitive adhesive of the same size are spliced in the non-display area. The contact part between the COP and the PET is a splicing line. And the sum of the thicknesses of the COP material and the pressure-sensitive adhesive after splicing is less than or equal to the sum of the thicknesses of PET and the pressure-sensitive adhesive.

As shown in fig. 9 (4), the COP and the PET are half-cut simultaneously on both sides of the splicing line, and the half-cut lines are shown as a half-cut line a and a half-cut line B in fig. 9, so that the precision of the distance between the half-cut line a and the half-cut line B can be ensured. This pitch corresponds to pitch L in fig. 5.

As shown in fig. 9 (5), COP, PET, and pressure sensitive adhesive between the half-cut line a and the half-cut line B are removed to form a U-shaped groove. The region where the remaining part of the COP is located at this time corresponds to the region where the first sub back film 2a in fig. 6 is located, and the region where the remaining part of the PET is located corresponds to the region where the second sub back film 2b in fig. 6 is located.

As shown in fig. 9 (6), a protective film 5 is attached over the cut COPs and PET to protect the COPs and PET.

Thus, the back film 2 is completed.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and the present invention shall be covered thereby. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. A display device, characterized in that the display device comprises:

the display substrate comprises a main body part, a bending part and a circuit board connecting part which are sequentially connected; the bending part is positioned at one end of the main body part, and the circuit board connecting part is positioned at the non-light-emitting side of the display substrate;

the back film comprises a first sub back film and a second sub back film which are arranged at intervals; the first sub-back film is connected with the back of the main body part and at least covers the main body part; the second sub back film is positioned between the first sub back film and the circuit board connecting part, is connected with the circuit board connecting part and at least covers the circuit board connecting part; and (c) a second step of,

the protective layer is positioned on the front surface of the bent part; the protective layer comprises a first end close to the main body part and a second end close to the circuit board connecting part; in a direction perpendicular to the plane of the main body part, the first end is partially overlapped with the first sub-back film, and the second end is partially overlapped with the second sub-back film;

the thickness of the first sub-back film is smaller than or equal to that of the second sub-back film.

2. The display device according to claim 1,

the crystallinity of the first sub-back film is smaller than that of the second sub-back film;

the toughness of the second sub-back membrane is greater than that of the first sub-back membrane.

3. The display device according to claim 2, wherein the material of the first sub-film comprises cyclic olefin polymer, and the material of the second sub-film comprises polyethylene terephthalate.

4. The display device according to claim 1, wherein the first sub-back film has a thickness in a range of 5 μm to 95 μm, and the second sub-back film has a thickness in a range of 10 μm to 95 μm.

5. The display device according to claim 1, wherein the first sub-backsheet comprises: a first side surface close to the bending part and a second side surface far away from the main body part; the joint of the first side surface and the second side surface is arranged in a chamfer angle manner;

and/or the presence of a gas in the gas,

the second sub-backsheet includes: a third side surface close to the bending part and a fourth side surface far away from the circuit board connecting part; the junction of the third side and the fourth side is chamfered.

6. The display device according to claim 1, wherein a bending radius of the bending portion is R, and a distance between a side surface of the first sub-backsheet near the bending portion and a side surface of the second sub-backsheet near the bending portion along a bending direction of the bending portion is L;

wherein L ═ pi R +100) μm.

7. The display device according to claim 1, wherein an area of the second sub-backsheet is smaller than an area of the first sub-backsheet;

the orthographic projection of the second sub-back membrane on the main body part is located in the orthographic projection range of the first sub-back membrane on the main body part.

8. The display device according to claim 1, wherein an overlapping area of the first end and the first sub-back film is smaller than an overlapping area of the second end and the second sub-back film.

9. The display device according to claim 1, wherein the display substrate includes a main display area and an auxiliary display area; the light transmittance of the part of the display substrate, which is positioned in the auxiliary display area, is greater than that of the part of the display substrate, which is positioned in the main display area;

the second sub-back film is located in the main display area.

10. The display device according to claim 9, wherein the display device further comprises: the image collector is arranged on one side, away from the main body part, of the first sub-back film;

the image collector is located in the auxiliary display area and is arranged in a staggered mode with the second sub-back membrane.

11. The display device according to claim 10, further comprising: the heat dissipation film is connected with the back surface of the first sub-back film;

the heat dissipation film is provided with an opening, and the orthographic projection of the image collector on the heat dissipation film is positioned in the opening.

12. The display device according to claim 11, further comprising: a support sheet disposed between the heat dissipation film and the second sub-backsheet;

the support sheet is configured to support the second sub-backsheet and the circuit board connection portion.

13. The display device according to claim 1, further comprising: the integrated circuit and the flexible circuit board are bound with the circuit board connecting part;

the integrated circuit and the flexible circuit board are both positioned on one side of the circuit board connecting part, which is far away from the main body part, and the flexible circuit board is positioned on one side of the integrated circuit, which is far away from the bending part.

14. The display device according to claim 1, characterized in that the display device further comprises: the polaroid, the adhesive layer and the cover plate are arranged on the front surface of the main body part and are sequentially laminated;

the cover plate covers the adhesive layer, the polarizer, the display substrate and the back film.

15. The display device according to claim 1, wherein the first sub-film comprises: the first adhesive layer is connected with the back surface of the main body part, and the first supporting layer is positioned on one side, far away from the main body part, of the first adhesive layer;

the second sub-backsheet includes: the second adhesive layer is connected with the circuit board connecting part, and the second supporting layer is positioned on one side, far away from the circuit board connecting part, of the second adhesive layer.