CN110536542B

CN110536542B - Flexible circuit board and manufacturing method thereof, display device and mobile terminal

Info

Publication number: CN110536542B
Application number: CN201910801385.4A
Authority: CN
Inventors: 郝佳; 问智博
Original assignee: Oppo Chongqing Intelligent Technology Co Ltd
Current assignee: Oppo Chongqing Intelligent Technology Co Ltd
Priority date: 2019-08-28
Filing date: 2019-08-28
Publication date: 2021-08-31
Anticipated expiration: 2039-08-28
Also published as: CN110536542A

Abstract

The invention provides a flexible circuit board, a manufacturing method thereof, a display device and a mobile terminal. The flexible circuit board comprises a body and a bending part arranged on one side of the body. The bending part is bent relative to the body along a bending line and comprises a flexible substrate and a conductive layer. The conducting layer is arranged on the flexible substrate, a first stress groove is formed in one side face, facing the flexible substrate, of the conducting layer, a second stress groove is formed in the other side face of the conducting layer, and the first stress groove and the second stress groove extend in the direction parallel to the bending line. By using the display device and the mobile terminal of the flexible circuit board, the occupied width of the flexible circuit board can be reduced by bending the bending part of the flexible circuit board, so that the frame width of the display device and the mobile terminal is reduced, and the narrow frame design is realized.

Description

Flexible circuit board and manufacturing method thereof, display device and mobile terminal

Technical Field

The present disclosure relates to electronic devices, and particularly to a flexible printed circuit board, a method for manufacturing the same, a display device, and a mobile terminal.

Background

At present, due to the rapid development of display technology, the OLED display screen has advantages of large viewing angle, power saving, fast response speed, no need of backlight, wide color gamut, high contrast, and Light and thin overall structure, so that the OLED display screen is more and more widely applied.

The front surface of the OLED display panel is generally divided into an active display area and a non-display area. The effective display area corresponds to the visual area, and the non-display area corresponds to the frame area. In the conventional OLED display panel, since the touch sensing circuit is disposed on the cover plate, the touch sensing circuit needs to be electrically connected to the driving chip. Binding the driver chip on the cover plate often occupies a wider frame width. Therefore, the width of the non-display area, especially the width of the frame where the driving chip is located, of the conventional OLED display panel is widened, so that the screen area ratio of the display screen cannot be further improved.

Disclosure of Invention

The purpose of the present disclosure is to provide a flexible circuit board, a display device, and a mobile terminal, so as to obtain a design effect of a narrow bezel.

The utility model provides a flexible circuit board, includes the body and locates the kink of body one side, the kink is for the body is bent along the bending line, the kink includes:

a flexible substrate;

the conducting layer is arranged on the flexible substrate, the conducting layer faces towards one side face of the flexible substrate, a first stress groove is formed in the other side face of the conducting layer, and the first stress groove and the second stress groove are parallel to the bending line direction in an extending mode.

A display device comprises a display panel and a COF circuit structure, wherein the COF circuit structure is arranged on one side of the display panel and is electrically connected with the display panel, and the COF circuit structure comprises a driving chip and a flexible circuit board;

the flexible circuit board comprises a body, a bending part and a turning part, wherein the turning part is arranged on one side of the bending part, which is far away from the body, the body is arranged on the front surface of the display panel, the body is used for being electrically connected with the display panel, the turning part is arranged on the back surface of the display panel through the bending part, and the driving chip is arranged on the turning part and is electrically connected with the flexible circuit board.

A mobile terminal comprises a display device and a shell, wherein the display device is installed on the shell.

Another aspect of the present application also provides a method for manufacturing a flexible circuit board.

A manufacturing method of a flexible circuit board comprises the following steps:

etching one side surface of the conductive layer to form a first stress groove extending along the direction of the bending line;

etching the other side surface of the conductive layer to form a second stress groove extending along the direction of the bending line on the side surface;

the conductive layer is bonded on the flexible substrate.

By using the display device and the mobile terminal with the flexible circuit board, the driving chip can be arranged on one side of the flexible circuit board, which is back to the display panel, by bending the bending part of the flexible circuit board, so that the occupied width of the flexible circuit board can be reduced, the frame width of the display device and the mobile terminal is reduced, and the narrow frame design is realized.

And the bent part of the flexible circuit board releases the stress generated by bending the bent part through the first stress groove and the second stress groove, so that the bent part can be smoothly and conveniently bent, and the bending radius of the bent part can be reduced. Therefore, the width of the bending part is further reduced by the flexible circuit board, so that the width of the frame occupied by the flexible circuit board is further reduced, and the narrow frame design of the electronic equipment is facilitated.

Drawings

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

fig. 2 is a schematic view of an electrical module according to the COF wiring structure of the display device shown in fig. 1;

fig. 3 is a schematic structural diagram of a display device according to another embodiment of the present disclosure;

FIG. 4 is a schematic structural diagram of the conductive layer at the bending portion shown in FIG. 3;

FIG. 5 is a schematic structural diagram of another embodiment of the display device shown in FIG. 3;

fig. 6 is a flow chart of a method of fabricating a flexible circuit board according to an embodiment of the present disclosure;

FIG. 7 is a schematic diagram of a corresponding detailed structure according to the manufacturing method shown in FIG. 6;

FIG. 8 is a flow chart of another embodiment of the method of fabrication shown in FIG. 6.

The reference numerals are explained below:

10. a display panel; 11. a substrate; 12. a display layer; 13. a touch layer; 20. a COF wiring structure; 21. a driving chip; 22. a flexible circuit board; 221. a flexible substrate; 222. a conductive layer; 223. a first stress groove; 224. a second stress groove; 225. a conductive wire; 226. a body; 227. a bending section; 228. a folding part; 23. an input electrode; 24. an output electrode; 30. and etching the cover plate.

Detailed Description

While this invention is susceptible of embodiment in different forms, there is shown in the drawings and will herein be described in detail, specific embodiments thereof with the understanding that the present description is to be considered as an exemplification of the principles of the disclosure and is not intended to limit the invention to that as illustrated herein.

Thus, a feature indicated in this specification will serve to explain one feature of an embodiment of the disclosure, and not to imply that every embodiment of the invention must have the stated feature. Further, it should be noted that this specification describes many features. Although some features may be combined to show a possible system design, these features may also be used in other combinations not explicitly described. Thus, the combinations illustrated are not intended to be limiting unless otherwise specified.

In the embodiments shown in the drawings, directional references (such as upper, lower, left, right, front and rear) are used to explain the structure and movement of the various elements of the invention not absolutely, but relatively. These descriptions are appropriate when the elements are in the positions shown in the drawings. If the description of the positions of these elements changes, the indication of these directions changes accordingly.

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus their repetitive description will be omitted.

The preferred embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

The present disclosure provides a flexible circuit board. The flexible circuit board can be applied to a plurality of fields such as automobiles, mobile terminals and the like. Also, the flexible circuit board may be applied to various devices such as a display device, a camera, or a microphone. The flexible circuit board is bent through the bending part, the occupied width of the flexible circuit board is reduced, the frame width of a display device and the like is reduced, and the narrow frame design of electronic equipment is achieved.

According to the flexible circuit board, the stress generated by bending the bent part is released, so that the width of the bent part of the flexible circuit board is further reduced, and the width of the occupied frame is further reduced. Thereby being beneficial to realizing the narrow frame design of the electronic equipment.

In particular, the present disclosure provides a display device and a mobile terminal using the same. The structure and function of the flexible circuit board are specifically described herein by taking a display device of a mobile terminal as an example. It is to be understood that the flexible circuit board of this embodiment mode can also be used in other electronic devices, and the display device can also be applied to other electronic devices. The application carrier of the flexible circuit board and the display device is not limited herein.

The mobile terminal comprises a display device and a shell. The display device is mounted on the housing. The shell wraps and covers the back of the display device from the outer side of the mobile terminal. The front surface of the display device is exposed and used for realizing the display function of the mobile terminal. Therefore, it is specified that the front surface of the display device faces the outside of the mobile terminal and the back surface of the display device faces the inside of the mobile terminal.

Referring to fig. 1, the display device of the present embodiment includes a display panel 10 and a COF circuit structure 20. The COF wiring structure 20 is disposed on one side of the display panel 10. The COF circuit structure 20 is used to connect the display panel 10 and a circuit board of the mobile terminal, so as to implement touch control and display functions of the display panel 10 and the mobile terminal.

The front surface of the display panel 10 is divided into an effective display area and a non-display area, and the non-display area is located at the periphery of the display area, adjacent to the display area. The display panel 10 has a substantially rectangular plate shape, and the display region and the non-display region are rectangular. The COF wiring structure 20 is mounted and connected corresponding to the non-display region.

The display panel 10 is an Organic Light-Emitting Diode (OLED) display panel 10. The display panel 10 includes a substrate 11, a cover plate (not shown), a display layer 12 between the substrate 11 and the cover plate, a touch layer 13, and a transparent conductive connection portion (not shown). Of course, the display panel 10 is not limited to such a hierarchical structure.

The substrate 11 is at the bottom of the OLED display panel 10 in the vertical direction as shown in fig. 1. The substrate 11 may be a glass substrate 11 manufactured based on a Low Temperature Polysilicon (LTPS) process.

The display layer 12 is disposed on the substrate 11. The display layer 12 includes respective OLED devices forming a plurality of pixel regions constituting a light emitting layer of the OLED display panel 10.

The touch layer 13 includes a touch driving circuit and a touch sensing circuit. The touch driving circuit and the touch sensing circuit can be directly fabricated on the substrate 11, that is, the circuit is formed on the substrate 11 by processes such as plating, transfer printing, developing, etching, etc.

The cof (chip on film) circuit structure 20 is a flexible circuit board on which the driving chip 21 for driving the display panel 10 is disposed. Therefore, the COF circuit structure 20 includes a driving chip 21 and a flexible circuit board 22. The driving chip 21 is packaged in the flexible circuit board 22. The COF wiring structure 20 electrically connects the driving chip 21 and the display panel 10 through the flexible circuit board 22, thereby implementing driving control of the display panel 10.

In an embodiment, the flexible circuit board 22 includes a flexible substrate 221 and a conductive layer 222, as shown in fig. 7. The flexible circuit board is single-sided packaged. The flexible substrate 221 serves as a base material of the flexible circuit board 22, so that the flexible circuit board 22 has flexibility and bendability. The conductive layer 222 is provided on the flexible substrate 221, and the conductive layer 222 is a metal layer and has a certain toughness. The conductive layer 222 can be bent along with the flexible substrate 221. It is understood that the flexible circuit board 22 may be a double-sided package, and is not limited thereto. That is, the conductive layer 222 of the flexible circuit board 22 is covered with a flexible packaging layer.

Referring to fig. 1, the flexible circuit board 22 includes a main body 226, a bending portion 227, and a turning portion 228 disposed on a side of the bending portion 227 away from the main body 226. The body 226 is disposed on the front surface of the display panel 10 for electrically connecting with the display panel 10. The folding portion 228 is folded and extended to the back surface of the display panel 10 by the folding portion 227. The body 226, the bending portion 227 and the folding portion 228 may be formed integrally or designed separately, and are not limited herein.

Specifically, in the present embodiment, the body 226 of the flexible circuit board 22 is disposed on the front surface of the display panel 10, and the body 226 is electrically connected to the display panel 10. Specifically, the body 226 is electrically connected to the display layer 12 and the touch layer 13.

The driving chip 21 is disposed on the folded portion 228 of the flexible circuit board 22. The bending portion 227 is used for bending the flexible circuit board 22, and the folding portion 228 is located on the back surface of the touch display panel 10. The driving chip 21 may be disposed on the folded portion 228 located on the back surface of the display panel 10, so that the flexible circuit board 22 occupies a larger width of the non-display area of the display panel 10 due to the arrangement of the driving chip 21, and thus, the effect of a narrow frame of the mobile terminal may be achieved, and the screen occupation ratio may be improved.

The COF wiring structure 20 further includes an input electrode 23 and an output electrode 24. The driver chip 21 is electrically connected to the flexible circuit board 22 via the input electrodes 23 and the output electrodes 24. The body 226 and the folded portion 228 are provided with an input electrode 23 and an output electrode 24. Therefore, input-side wiring and output-side wiring connected to the driver chip 21 are provided on the flexible circuit board 22. The input terminal wiring electrically connects the input electrode 23 and the driver chip 21, and the output terminal wiring electrically connects the output electrode 24 and the driver chip 21.

In this embodiment, the conductive layer 222 at the bending portion 227 is to avoid damage during the bending process. Referring to fig. 3 and 4, a first stress groove 223 is formed on a side of the conductive layer 222 of the bending portion 227 facing the flexible substrate 221. The other side of the conductive layer 222 is formed with a second stress groove 224. The first stress groove 223 and the second stress groove 224 extend in a direction parallel to the bending line. The first stress groove 223 and/or the second stress groove 224 are plural.

When the bending portion 227 is bent, the inner arc-shaped wall of the bending portion 227 is pressed, and the outer arc-shaped wall is pulled. Therefore, in the process of deforming the bent portion 227, the conductive layer 222 located at the bent portion 227 is prone to be torn or broken due to uneven force. In contrast, in the bent portion 227 of the flexible circuit board 22 according to the present embodiment, the first stress groove 223 and the second stress groove 224 are respectively opened on two side surfaces of the conductive layer 222 of the bent portion 227. The first stress groove 223 and the second stress groove 224 can help to release the stress concentration generated by bending, and the first stress groove 223 and the second stress groove 224 can also provide a deformation buffering space for the deformation amount of the conductive layer 222, which helps the conductive layer 222 to deform at the bending portion 227.

Therefore, the bending portion 227 of the present embodiment facilitates bending, and reduces the bending stress at the bending portion 227, so as to reduce the curvature radius of the inner arc-shaped wall and the outer arc-shaped wall when the bending portion 227 needs to be bent, thereby further reducing the width occupied by the COF circuit structure 20 in the non-display area of the display device, that is, reducing the width of the non-display area of the display device, and implementing a narrow frame design of the mobile terminal.

Moreover, the conductive layer 222 can improve the yield of the flexible circuit board 22, and improve the reliability and consistency of the mobile terminal. The metal conductive wire inside the bent portion 227 is easily broken due to the deformation of the bent portion 227.

In this embodiment, the first stress grooves 223 and the second stress grooves 224 are staggered. The first stress groove 223 and the second stress groove 224 are disposed in a vertically staggered manner, so that the conductive layer 222 is prevented from being affected by the thin portion due to the opening of the first stress groove 223 and the second stress groove 224.

The plurality of first stress grooves 223 are uniformly distributed on the side surface of the conductive layer 222 facing the flexible substrate 221, so that the extrusion stress of the inner arc-shaped wall of the bending portion 227 can be uniformly dispersed, and the stress concentration of the inner arc-shaped wall of the bending portion is prevented from being broken.

Moreover, the plurality of second stress grooves 224 are uniformly distributed on the other side surface of the conductive layer 222, so that the pulling stress of the outer arc-shaped wall of the bending portion 227 can be uniformly dispersed, and the stress concentration of the outer arc-shaped wall of the bending portion 227 is prevented from being broken.

The first stress groove 223 and the second stress groove 224 are square grooves. That is, the cross sections of the first stress groove 223 and the second stress groove 224 are rectangular, and the first stress groove 223 and the second stress groove 224 in the form of square grooves are convenient to manufacture and implement.

Specifically, the cross sections of the first stress groove 223 and the second stress groove 224 are square. Also, the first stress groove 223 and the second stress groove 224 have the same notch width. The groove depth of the first stress groove 223 and the second stress groove 224 is equal to the notch width. The first stress groove 223 and the second stress groove 224 have a groove depth of half of the thickness of the conductive layer.

The distance between two adjacent first stress grooves 223 or two adjacent second stress grooves 224 is 3 times larger than the notch width of the first stress groove 223 or the second stress groove 224. Therefore, after the first stress groove 223 and the second stress groove 224 are opened in the conductive line layer 222, the thickness of the conductive layer 222 is substantially the same. Therefore, the thickness of the conductive layer 222 is substantially the same, so that the strength of the conductive layer 222 is substantially the same, and the conductive layer 222 can uniformly disperse the bending stress, thereby avoiding stress concentration and easily bending and damaging the conductive layer. Therefore, the conductive layer 222 of the flexible circuit board can avoid uneven thickness of the conductive layer 222 due to the opening of the first stress groove 223 and the second stress groove 224, and uneven stress applied to various parts of the conductive layer 222.

Referring to fig. 5, it is understood that in other embodiments, the cross-sections of the first stress groove 223 and the second stress groove 224 may also be arc-shaped, and the conductive layer 222 is wavy. The arc-shaped first stress groove 223 and the arc-shaped second stress groove 224 can help to disperse stress and better avoid stress concentration caused by bending.

Referring to fig. 7, the conductive layer 222 includes a plurality of conductive lines 225. The conductive line 225 extends in a direction perpendicular to the meander line. Each conductive line 225 is provided with a first stress groove 223 and a second stress groove 224. The conductive line 225 is used as an input terminal wiring for connecting the input electrode 23 and the driver chip 21 and an output terminal wiring for connecting the output electrode 24 and the driver chip 21. The conductive line 225 is connected with current to turn on the driving chip 21.

Specifically, in the present embodiment, when the flexible circuit board 22 is packaged, two sides of the conductive layer 222 are provided with adhesive layers. The glue layer fills the first stress trench 223 and the second stress trench 224. Since the adhesive layer has a certain elasticity, the adhesive layer filled in the first stress groove 223 and the second stress groove 224 provides a certain elastic buffer and elastic support for the conductive line 225. The filling glue layer can further enhance the bending elasticity of the conductive wire 225, and the conductive wire 225 is prevented from being damaged in the bending process.

Specifically, the application further provides a manufacturing method of the flexible circuit board.

Referring to fig. 6, a method for manufacturing a flexible circuit board according to the present embodiment includes:

step S1, a side surface of the conductive layer is etched to form a first stress groove extending along the bend line direction.

Referring to fig. 7, fig. 7 shows a specific process of the method for manufacturing the flexible printed circuit board. Specifically, the step of etching the conductive layer is to etch the side surface of the conductive layer by reactive ion bombardment. It will be appreciated that for the etching process of the conductive layer, other etching methods, such as photolithographic etching, etc., may also be used. Step S1 is to etch one side surface of the conductive layer to form a first stress groove.

Before etching the conductive layer, an etching cover plate 30 is placed on the processed side of the conductive layer for reactive ion bombardment etching.

Referring to fig. 8, the method for manufacturing a flexible circuit board according to the present embodiment further includes step S2, turning the conductive layer by 180 degrees.

When the other side of the conductive layer needs to be processed, the conductive layer needs to be turned over so as to facilitate processing.

Step S3, the other side surface of the conductive layer is etched to form a second stress groove extending along the direction of the bend line.

Specifically, the step of etching the conductive layer is to etch the side surface of the conductive layer by reactive ion bombardment. It will be appreciated that for the etching process of the conductive layer, other etching methods, such as photolithographic etching, etc., may also be used.

Before the conductive layer is etched in step S3, an etching cover 30 is placed on the processed side of the conductive layer for reactive ion bombardment etching.

The method for manufacturing a flexible circuit board according to this embodiment further includes, in step S4, translating the etching cover plate on the side surface of the conductive layer in a direction perpendicular to the bending line.

When the etching cap plate 30 is placed, the etching cap plate 30 needs to be shifted by a certain distance relative to the placing position of the etching cap plate 30 in step S1, so that the gap between two adjacent etching cap plates 30 and the first stress groove 223 are arranged in a staggered manner.

Since the cross sections of the first stress groove 223 and the second stress groove 224 are square. Also, the first stress groove 223 and the second stress groove 224 have the same notch width. The groove depth of the first stress groove 223 and the second stress groove 224 is equal to the notch width. The first stress groove 223 and the second stress groove 224 have a groove depth of half of the thickness of the conductive layer. The groove opening widths of the first stress groove 223 and the second stress groove 224 are defined as one distance unit. Therefore, when placing the etching cap 30, it is necessary to shift the etching cap 30 by 2 distance units with respect to the placing position of the etching cap 30 in step S1, that is, the etching cap 30 is shifted by 2 distance units to the left or right in fig. 4.

Therefore, the other side surface of the conductive layer is etched in step S3, and the second stress grooves 224 are formed to be vertically staggered with respect to the first stress grooves 223.

In step S5, the conductive layer is bonded to the flexible substrate.

The conductive layer is bonded to the flexible substrate 221 by a glue layer to fix the conductive layer.

According to the flexible circuit board manufactured by the method, when the bending part 227 is bent, the first stress groove 223 and the second stress groove 224 are respectively arranged on the two opposite side surfaces of the conductive layer at the bending part 227, and the stress generated by bending the conductive layer can be dispersed through the first stress groove and the second stress groove 224, so that stress concentration is avoided, and the conductive layer is prevented from being damaged and losing efficacy. The flexible circuit board can improve the product yield of the flexible circuit board.

The method for manufacturing a flexible printed circuit board according to this embodiment further includes a step S6 of etching the conductive layer in a direction perpendicular to the first stress groove 223 and the second stress groove 224 to divide the conductive layer into a plurality of conductive lines 225.

Similarly, before the conductive layer is etched in step S6, the etching cap 30 is placed on the processed side of the conductive layer, and the placing direction of the etching cap 30 is perpendicular to the placing direction of the etching cap 30 in step S1 and step S3, so that the plurality of conductive lines 225 are formed in the direction perpendicular to the first stress groove 223 and the second stress groove 224.

It is understood that in other embodiments, a flexible encapsulation layer may also be bonded over conductive lines 225. The flexible encapsulation layer encapsulates both sides of the conductive wires 225.

While the present disclosure has been described with reference to several exemplary embodiments, it is understood that the terminology used is intended to be in the nature of words of description and illustration, rather than of limitation. As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalences of such meets and bounds are therefore intended to be embraced by the appended claims.

Claims

1. The utility model provides a flexible circuit board, its characterized in that includes the body and locates the kink of body one side, the kink for the body is bent along the bending line, the kink includes:

a flexible substrate;

the conductive layer is a metal layer and is arranged on the flexible substrate, a first stress groove is formed in one side surface, facing the flexible substrate, of the conductive layer, a second stress groove is formed in the other side surface of the conductive layer, and the first stress groove and the second stress groove extend in a direction parallel to the bending line;

glue layers are arranged on the side surface of the conducting layer, facing the flexible substrate, and the other side surface of the conducting layer, and the glue layers are filled in the first stress groove and the second stress groove; the conductive layer is adhered to the flexible substrate.

2. The flexible circuit board of claim 1, wherein the first stress groove and the second stress groove are staggered.

3. The flexible circuit board of claim 1, wherein the first stress groove and/or the second stress groove are multiple.

4. The flexible circuit board of claim 3, wherein the first stress grooves are uniformly distributed on a side surface of the conductive layer facing the flexible substrate, and the second stress grooves are uniformly distributed on the other side surface of the conductive layer.

5. The flexible circuit board of claim 1, wherein the first stress slot and the second stress slot are square slots.

6. The flexible circuit board of claim 1, wherein the first stress slot and the second stress slot are square in cross-section.

7. The flexible circuit board of claim 1, wherein the first stress groove and the second stress groove have a groove depth equal to half the thickness of the conductive layer.

8. The flexible circuit board according to claim 3, wherein a distance between two adjacent first stress grooves or two adjacent second stress grooves is greater than 3 times a width of the notch of the first stress groove or the second stress groove.

9. The flexible circuit board of claim 1, wherein the conductive layer has a plurality of conductive lines extending in a direction perpendicular to the bending line, and each of the conductive lines has the first stress groove and the second stress groove.

10. A display device, comprising a display panel and a COF circuit structure, wherein the COF circuit structure is disposed on one side of the display panel and electrically connected to the display panel, and the COF circuit structure comprises a driving chip and the flexible circuit board of any one of claims 1 to 9;

the flexible circuit board comprises a body, a bending part and a folding part, wherein the folding part is arranged on one side of the bending part, which is far away from the body, the body is arranged on the front surface of the display panel, the body is used for being electrically connected with the display panel, the folding part is arranged on the back surface of the display panel through the bending part, and the driving chip is arranged on the folding part and is electrically connected with the flexible circuit board.

11. The display device according to claim 10, wherein the COF wiring structure further comprises an input electrode and an output electrode, and the driving chip is electrically connected to the flexible circuit board through the input electrode and the output electrode.

12. The display device according to claim 10, wherein the display panel is an organic light emitting diode display panel.

13. A mobile terminal comprising the display device of any one of claims 10-12 and a housing, the display device being mounted on the housing.

14. A method for manufacturing a flexible circuit board is characterized by comprising the following steps:

etching one side surface of the conductive layer to form a first stress groove extending along the direction of the bending line; wherein the conductive layer is a metal layer;

the conducting layer is adhered to the flexible substrate; the side face, facing the flexible substrate, of the conducting layer and the other side face of the conducting layer are both provided with glue layers, and the glue layers are filled in the first stress groove and the second stress groove.

15. The method for manufacturing a flexible circuit board according to claim 14, further comprising the step of,

and translating the etched cover plate on the side surface of the conductive layer along the direction vertical to the bending line.

16. The method for manufacturing a flexible circuit board according to claim 14, further comprising the step of,

and etching the conductive layer along a direction vertical to the first stress groove and the second stress groove to enable the conductive layer to be divided into a plurality of conductive wires.

17. The method of claim 14, wherein the step of etching the conductive layer is specifically etching the side of the conductive layer by reactive ion bombardment.