Flexible circuit board and display device

Abstract

The present disclosure provides a flexible circuit board and a display device, the flexible circuit board comprising a substrate and at least one signal line, the signal line comprising two sub-signal lines oppositely arranged on two sides of the substrate respectively, at least one of the two sub-signal lines comprising a plurality of first portions and a plurality of second portions, the first portions and the second portions being alternately arranged and connected end to end along the direction of the signal line, and the first portions having a thickness greater than that of the second portions. By alternately changing the thickness of at least one of the two sub-signal lines on the two sides of the substrate along the direction of the signal line, the length of the stress neutral plane in the direction of the signal line can be extended. Since the longer the stress neutral plane is under the same stress on the flexible circuit board, the stress distributed at each position will be smaller, which can avoid the signal line breakage caused by stress concentration, thereby solving the problem of poor reliability of the flexible circuit board.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of display, in particular, to a flexible circuit board and a display device comprising the same. BACKGROUND

[0002] Currently, a display device is usually composed of a display panel and a flexible circuit board. In a specific case, a predetermined area of the flexible circuit board is bent, and the bending performance of the flexible circuit board greatly affects the reliability of the display device. Therefore, how to improve the bending performance of the flexible circuit board becomes a problem to be solved. SUMMARY

[0003] The present disclosure provides a flexible circuit board and a display device, the flexible circuit board comprising a substrate and a signal line, the signal line comprising two sub-signal lines oppositely arranged on two sides of the substrate, and at least one of the two sub-signal lines alternately changes in thickness along the extension direction of the signal line, so that the stress neutral plane of the connecting line is a curve, and the signal line breakage caused by stress concentration can be avoided, and the problem of poor bending performance of the flexible circuit board is solved.

[0004] The first aspect of the present disclosure provides a flexible circuit board, comprising a substrate and at least one signal line, the signal line comprising two sub-signal lines oppositely arranged on two sides of the substrate, at least one of the two sub-signal lines comprising a plurality of first portions and a plurality of second portions, the first portions and the second portions being alternately arranged and connected end to end along the direction of the signal line, and the thickness of the first portions being greater than the thickness of the second portions.

[0005] The present disclosure forms two sub-signal lines on two sides of the substrate, and the thickness of at least one of the two sub-signal lines alternately changes along the extension direction of the signal line, so that the stress neutral plane of the flexible circuit board is a curve along the direction of the signal line, and the length of the stress neutral plane along the direction of the signal line is extended. Since the longer the stress neutral plane is under the same stress, the stress distributed at each position will be smaller, this way can avoid the signal line breakage caused by stress concentration, and further solve the problem of poor reliability of the flexible circuit board.

[0006] In an implementation form of the first aspect of the present disclosure, the first portions and the second portions are of the same layer and material.

[0007] In the above scheme, the materials of the first portions and the second portions are the same, so that when the sub-signal line is subjected to bending stress, the stress is uniformly distributed on the sub-signal line, and stress concentration can be avoided.

[0008] In an implementation form of the first aspect of the present disclosure, one of the two sub-signal lines is composed of a plurality of first portions and a plurality of second portions.

[0009] In the above scheme, the thickness of one of the two sub-signal lines in the extension direction thereof alternately changes, so that the formation of the efficiency-reducing structure can be avoided.

[0010] In an implementation form of the first aspect of the present disclosure, two of the two sub-signal lines are composed of a plurality of first portions and a plurality of second portions.

[0011] For example, the first portion of one of the two sub-signal lines is in the same projection on the substrate as the second portion of the other of the two sub-signal lines.

[0012] In the above scheme, the thickness of one of the two sub-signal lines in the extension direction thereof alternately changes, so that the length of the stress neutral plane can be further extended, the stress distribution can be more uniform, and the connection line can be prevented from breaking, thereby ensuring the reliability of the flexible circuit board.

[0013] In an implementation form of the first aspect of the present disclosure, the shape of at least one of the two surfaces of the sub-signal line composed of the plurality of first portions and the plurality of second portions, which faces the substrate or is away from the substrate, is a curved shape.

[0014] In an implementation form of the first aspect of the present disclosure, the surface of the sub-signal line composed of the plurality of first portions and the plurality of second portions, which faces the substrate, is a curved shape, the surface of the sub-signal line, which is away from the substrate, is a plane, and the surface of the substrate, which faces the sub-signal line composed of the plurality of first portions and the plurality of second portions, is conformal to the surface of the sub-signal line, which faces the substrate.

[0015] In an implementation form of the first aspect of the present disclosure, the surface of the sub-signal line composed of the plurality of first portions and the plurality of second portions, which is away from the substrate, is a curved shape, and the surface of the sub-signal line, which faces the substrate, is a plane.

[0016] In an implementation form of the first aspect of the present disclosure, the curved shape includes a zigzag shape and a wave shape.

[0017] In an implementation form of the first aspect of the present disclosure, the plurality of first portions and the plurality of second portions are located in the bending region of the flexible circuit board.

[0018] The second aspect of the present disclosure provides a display device, which comprises a display panel and a flexible circuit board as described in the first aspect. The flexible circuit board is bonded to the display panel. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a top view schematic diagram of the connection between the flexible circuit board and the display panel provided by at least one embodiment of the present disclosure.

[0020] Figure 2 is a cross-sectional view schematic diagram of the connection between the flexible circuit board and the display panel provided by at least one embodiment of the present disclosure.

[0021] Figure 3 is a top view schematic diagram of a flexible circuit board provided by at least one embodiment of the present disclosure.

[0022] Figure 4 is a cross-sectional view schematic diagram of a flexible circuit board provided by at least one embodiment of the present disclosure.

[0023] Figure 5 is a cross-sectional view schematic diagram of a flexible circuit board provided by at least one embodiment of the present disclosure.

[0024] Figure 6 is a cross-sectional view schematic diagram of a flexible circuit board provided by at least one embodiment of the present disclosure.

[0025] Figure 7 is a cross-sectional view schematic diagram of a flexible circuit board provided by at least one embodiment of the present disclosure.

[0026] Figure 8 is a cross-sectional view schematic diagram of a flexible circuit board provided by at least one embodiment of the present disclosure.

[0027] Figure 9 is a cross-sectional view schematic diagram of a flexible circuit board provided by at least one embodiment of the present disclosure.

[0028] Figure 10 is a cross-sectional view schematic diagram of a flexible circuit board provided by at least one embodiment of the present disclosure.

[0029] Figure 11 is a cross-sectional view schematic diagram of a flexible circuit board provided by at least one embodiment of the present disclosure.

[0030] Figure 12 is a cross-sectional view schematic diagram of a flexible circuit board provided by at least one embodiment of the present disclosure.

[0031] Figure 13 is a cross-sectional view schematic diagram of a flexible circuit board provided by at least one embodiment of the present disclosure.

[0032] Figure 14 is a top view schematic diagram of a display device provided by at least one embodiment of the present disclosure.

[0033] Figure 15 is a cross-sectional view schematic diagram of a display device provided by at least one embodiment of the present disclosure. DETAILED DESCRIPTION

[0034] With reference to the drawings of the embodiments of the present disclosure, the technical solutions in the embodiments of the present disclosure will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, but not all the embodiments. Based on the embodiments of the present disclosure, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of the present disclosure.

[0035] To facilitate the understanding of the flexible circuit board and the display device provided by the embodiments of the present disclosure, the related terms involved in the present disclosure are explained as follows.

[0036] Stress neutral surface: the interface between the tensile zone and the compression zone of an object, and the surface formed by all the positions in the material where the tangential stress is zero when the object is bent.

[0037] Curve: a continuous line, and in the present disclosure, the curve specifically refers to a continuous line other than a straight line, for example, a broken line, an arc line, and a wavy line.

[0038] In a display device, a flexible circuit board and a display panel are usually included, and the two are electrically connected to each other. Specifically, the flexible circuit board includes signal lines for connecting the display panel and electronic components. When the flexible circuit board is bent due to stress, the signal lines may be broken due to stress concentration, thereby resulting in poor reliability of the flexible circuit board.

[0039] Therefore, at least one embodiment of the present disclosure provides a flexible circuit board, which includes a substrate and at least one signal line. The signal line includes two sub-signal lines arranged on opposite sides of the substrate, respectively. At least one of the two sub-signal lines includes a plurality of first portions and a plurality of second portions. The first portions and the second portions are alternately arranged along the direction of the signal line and connected end to end. The thickness of the first portions is greater than the thickness of the second portions. In the present disclosure, by forming two sub-signal lines on both sides of the substrate, and by alternately changing the thickness of at least one of the two sub-signal lines along the direction of the signal line, the stress neutral surface of the flexible circuit board is a curve along the direction of the signal line, thereby prolonging the total length of the stress neutral surface along the direction of the signal line (i.e., the length of the curve between two points is greater than the length of the straight line). Since the longer the stress neutral surface is under the same stress, the stress distributed at each position is smaller, this method can avoid the signal line breakage caused by stress concentration, thereby solving the problem of poor reliability of the flexible circuit board.

[0040] Below, the flexible circuit board and display device in at least one embodiment of the present disclosure are described in conjunction with the drawings. In addition, as shown in the drawings, in at least one embodiment of the present disclosure, a space rectangular coordinate system is established with the surface of the flexible circuit board (for example, the surface facing the user) as the reference to define the positions of various elements in the display panel and even the display device. In the space rectangular coordinate system, the X-axis and the Y-axis are parallel to the surface of the display panel, the X-axis is parallel to the signal line in the flexible circuit board, the Y-axis is perpendicular to the signal line in the flexible circuit board, and the Z-axis is perpendicular to the surface of the display panel.

[0041] Figure 1 is a top view schematic diagram of the connection of the flexible circuit board and the display panel provided in at least one embodiment of the present disclosure. Figure 2 is a cross-sectional view schematic diagram of the connection of the flexible circuit board and the display panel provided in at least one embodiment of the present disclosure. As shown in Figure 1 and Figure 2 , the flexible circuit board 100 is used to be arranged in the display device and is bonded with the display panel 200. For example, the display panel 200 includes a display area 210 and a non-display area 220, and a plurality of OLED light emitting devices are arranged in the display area 210.

[0042] Specifically, the flexible circuit board 100 includes a bending area S1, and the bending area S1 is arranged corresponding to the non-display area 220 of the display panel 200, and the flexible circuit board 100 is bent at the bending area S1 to make the flexible circuit board 100 bent to the non-light-emitting side of the display panel 200. The flexible circuit board 100 includes a bonding area S2 on one side of the bending area S1 for bonding with the display panel 200, and one end of the flexible circuit board 100 is provided with a connector for connecting with the main board of the display device to electrically connect the display panel 200 and the main board of the display device. In addition, the flexible circuit board 100 is also connected with electronic components such as control chips, resistors or capacitors to form a control circuit of the display panel 200, so that the display panel 200 displays images according to the control signal.

[0043] To improve the bending performance of the flexible circuit board 100 in the bending region S1, in at least one embodiment of this disclosure, at least one sub-signal line 120 in the bending region S1 of the flexible circuit board 100 includes a plurality of alternately connected first portions and a plurality of second portions. That is, the plurality of first portions and the plurality of second portions are located in the bending region S1 of the flexible circuit board 100, so that the thickness of at least one sub-signal line 120 in the bending region S1 is different along the signal line 120 direction. Specifically, in order to make the thickness of at least one sub-signal line 120 different along the signal direction, at least one of the two surfaces of the sub-signal line 120 composed of the plurality of first portions and the plurality of second portions is curved. That is, at least one surface of the at least one sub-signal line 120 facing the substrate or the surface away from the substrate is curved. Further, the curved shape can include a broken line shape and a wavy shape.

[0044] In at least one embodiment of at least one embodiment of this disclosure, the surface of the sub-signal line 120, which is composed of a plurality of first portions and a plurality of second portions, facing away from the substrate is curved, and the surface facing the substrate is planar. That is, the contact surface between the substrate and the sub-signal line 120 is planar. Further, refer to the following... Figures 3-6 The present disclosure describes a flexible circuit board in which the contact surface between the substrate and the sub-signal line 120 is planar, and the surface of the sub-signal line 120 away from the substrate is zigzag-shaped.

[0045] Figure 3 yes Figure 1 An enlarged schematic diagram of a portion of region S3 within the mid-bend zone. (See diagram below.) Figure 3 The flexible circuit board 100 shown includes a substrate 110 and a plurality of signal lines 120. Figure 4 This is at least one embodiment of at least one of the embodiments of this disclosure. Figure 3 A cross-sectional view of line AB in the middle. (See diagram below.) Figure 4 As shown, the signal line 120 in the bending area S1 of the flexible circuit board 100 includes a first sub-signal line 121 and a second sub-signal line 122 respectively disposed on both sides of the substrate 110. That is, the flexible circuit board 100 is a double-layer circuit board. At least one of the first sub-signal line 121 and the second sub-signal line 122 is connected to a control circuit. At least one of the first sub-signal line 121 and the second sub-signal line 122 includes multiple first portions and multiple second portions. The first portions and the second portions are alternately arranged along the direction of the signal line 120 and connected end-to-end, and the thickness of the first portion is greater than the thickness of the second portion.

[0046] For example, the first sub-signal line 121 includes a first portion and a second portion with different thicknesses along the X-axis direction. The thickness of the second sub-signal line 122 along the X-axis direction remains unchanged. That is, in the X-axis direction, the thickness of the first sub-signal line 121 is alternately changed, and the thickness of the second sub-signal line 122 is uniform. Specifically, the thickness difference between the first portion and the second portion can be between 0.3 microns and 6 microns. For example, the thickness difference between the first portion and the second portion is 0.5 microns, 1 micron, 3 microns, or 5 microns.

[0047] By changing the thickness of at least one sub-signal line 120 along the X-axis direction, when the flexible circuit board 100 is bent along the X-axis direction, the stress neutral plane 130 of the flexible circuit board 100 is bent, so that the length of the stress neutral plane 130 is extended, and when the flexible circuit board 100 is subjected to stress, the stress is more evenly distributed, so that the breaking strength of the signal line 120 can be improved, and the signal line 120 can be prevented from being broken due to stress concentration, thereby solving the problem of poor reliability of the flexible circuit board 100.

[0048] Specifically, the materials of the first sub-signal line 121 and the second sub-signal line 122 can be metal materials, such as copper, aluminum, or silver with good electrical conductivity, etc. In at least one embodiment of the present disclosure, the materials of the first sub-signal line 121 and the second sub-signal line 122 are both copper.

[0049] Further, the first portion 1211 and the second portion 1212 in the first sub-signal line 121 are the same layer and the same material. For example, the materials of the plurality of first portions 1211 and the plurality of second portions 1212 are both copper.

[0050] The method for forming the first sub-signal line 121 includes the following steps. First, a conductive line with uniform thickness is formed on one side of the substrate 110. Second, the thickness of the conductive line in the region where the first portion 1211 is located is increased, or the thickness of the conductive line in the region where the second portion 1212 is located is reduced. Specifically, the thickness of the conductive line can be increased by electroplating, chemical vapor deposition, and physical vapor deposition processes, and the thickness of the conductive line can be reduced by etching and the like.

[0051] Since the thickness of the second sub-signal line 122 is uniform, the second sub-signal line 122 can be made by a conventional process, without additional manufacturing processes, thereby avoiding a significant reduction in the formation efficiency of the flexible circuit board 100.

[0052] Since different materials have different elastic moduli and strengths, the materials of the first part and the second part will affect the position of the stress neutral surface 130. The first part and the second part are in the same layer and made of the same material, which can avoid stress concentration and breakage of the sub-signal line 120 due to the different properties of the two materials, and can improve the bending performance of the flexible circuit board 100.

[0053] In such Figure 4 In the three-layer structure shown, the first sub-signal line 121 and the second sub-signal line 122 are located on both sides of the substrate 110 and are made of the same material. The position of the stress neutral surface 130 of this three-layer structure mainly depends on the thickness of the first sub-signal line 121 and the second sub-signal line 122. When the difference in thickness between the first sub-signal line 121 and the second sub-signal line 122 is equal to zero, the stress neutral surface 130 coincides with the centerline of the substrate 110. When the difference in thickness between the first sub-signal line 121 and the second sub-signal line 122 is greater than zero and less than a predetermined threshold, the stress neutral surface 130 will be located in the substrate, and the stress neutral surface 130 will be close to the sub-signal line with the larger thickness.

[0054] When the thickness of the first sub-signal line 121 is greater than the thickness of the second sub-signal line 122, and the difference between the two is greater than a predetermined threshold, the stress neutral surface 130 will be located in the first sub-signal line 121; otherwise, the stress neutral surface 130 will be located in the second sub-signal line 122.

[0055] In one optional implementation of this disclosure, such as Figure 4 As shown, to further improve the strength of the signal line 120 and prevent it from breaking, the thickness of the second sub-signal line 122 is less than the thickness of the first portion of the first sub-signal line 121, but greater than the thickness of the second portion of the first sub-signal line 121. The thickness difference between the first portion 1211 of the first sub-signal line 121 and the second sub-signal line 122 is less than a predetermined value, and the thickness difference between the second portion 1212 of the first sub-signal line 121 and the second sub-signal line 122 is also less than a predetermined value. Thus, the stress neutral surface 130 is located in the substrate 110, and according to the thickness variation of the first sub-signal line 121, the stress neutral surface 130 is located on both sides of the centerline of the substrate 110.

[0056] In one optional implementation of this disclosure, such as Figure 5As shown, the thickness of the second sub-signal line 122 is less than the thickness of the first part of the first sub-signal line 121 and greater than the thickness of the second part of the first sub-signal line 121, the thickness difference between the first part 1211 of the first sub-signal line 121 and the second sub-signal line 122 is greater than a predetermined value, and the thickness difference between the second part 1212 of the first sub-signal line 121 and the second sub-signal line 122 is greater than a predetermined value. This can make the stress neutral plane 130 alternately located on both sides of the substrate 110, so that the length of the stress neutral plane 130 is further prolonged, the breaking strength of the signal line 120 can be further improved, the signal line 120 can be prevented from being broken due to stress concentration, and thus the problem of poor reliability of the flexible circuit board 100 is solved.

[0057] In an optional embodiment of at least one of the embodiments of the present disclosure, as shown in Figure 6 As shown, the thickness of the second sub-signal line 122 is less than the thickness of the first part of the first sub-signal line 121 and greater than the thickness of the second part of the first sub-signal line 121, the thickness difference between the first part 1211 of the first sub-signal line 121 and the second sub-signal line 122 is greater than a predetermined value, and the thickness difference between the second part 1212 of the first sub-signal line 121 and the second sub-signal line 122 is greater than a predetermined value. This can make the stress neutral plane 130 alternately located on both sides of the substrate 110, so that the length of the stress neutral plane 130 is further prolonged, the breaking strength of the signal line 120 can be further improved, the signal line 120 can be prevented from being broken due to stress concentration, and thus the problem of poor reliability of the flexible circuit board 100 is solved.

[0058] In order to further improve the strength of the signal line 120 and prevent the signal line 120 from being broken, in an optional embodiment of at least one of the embodiments of the present disclosure, two of the two sub-signal lines 120 are composed of a plurality of first parts and a plurality of second parts. That is, the first sub-signal line 121 and the second sub-signal line 122 are both periodically changed in thickness along the X-axis direction. For example, the first sub-signal line 121 includes a first part 1211 and a second part 1212 which are different in thickness along the X-axis direction. The second sub-signal line 122 includes a first part 1221 and a second part 1222 which are different in thickness along the X-axis direction.

[0059] Figure 7 is a cross-sectional view of the AB line in the embodiment of at least one of the embodiments of the present disclosure along Figure 1 As shown, the thickness of the second sub-signal line 122 is less than the thickness of the first part of the first sub-signal line 121 and greater than the thickness of the second part of the first sub-signal line 121, the thickness difference between the first part 1211 of the first sub-signal line 121 and the second sub-signal line 122 is greater than a predetermined value, and the thickness difference between the second part 1212 of the first sub-signal line 121 and the second sub-signal line 122 is greater than a predetermined value. This can make the stress neutral plane 130 alternately located on both sides of the substrate 110, so that the length of the stress neutral plane 130 is further prolonged, the breaking strength of the signal line 120 can be further improved, the signal line 120 can be prevented from being broken due to stress concentration, and thus the problem of poor reliability of the flexible circuit board 100 is solved. Figure 7As shown, the orthographic projection of the first portion of one of the two sub-signal lines 120 onto the substrate 110 and the orthographic projection of the second portion of the other sub-signal line 120 onto the substrate 110 are substantially completely coincident. Optionally, the thicker first portion 1211 of the first sub-signal line 121 is positioned opposite the thinner second portion 1222 of the second sub-signal line 122. Therefore, the thickness difference between the first sub-signal line 121 and the second sub-signal line 122 increases, thereby increasing the distance between the stress neutral surface 130 at the location of the signal line 120 on the flexible circuit board 100 and the substrate 110.

[0060] Optionally, the first portion 1211 of the first sub-signal line 121 and the first portion 1221 of the second sub-signal line 122 have the same thickness, and the second portion 1212 of the first sub-signal line 121 and the second portion 1222 of the second sub-signal line 122 have the same thickness. This ensures that the stress distribution on the first sub-signal line 121 and the second sub-signal line 122 is substantially the same, thereby avoiding stress concentration on either the first sub-signal line 121 or the second sub-signal line 122, preventing breakage of either the first sub-signal line 121 or the second sub-signal line 122, and thus improving the strength of the signal line 120 and increasing the reliability of the flexible circuit board 100.

[0061] Optionally, the first and second parts are approximately equal in length along the X-axis. The periodic alternation of the first and second parts makes the stress neutral surface 130 smoother and avoids stress concentration.

[0062] Figure 8 In at least one embodiment of this disclosure, along with Figure 1 A cross-sectional view of line AB in the middle. (See diagram below.) Figure 8 As shown, this embodiment is similar to... Figure 7 The difference in the illustrated embodiment lies only in the fact that the orthographic projection of the first portion of one of the two sub-signal lines 120 onto the substrate 110 coincides with the orthographic projection of the second portion of the other sub-signal line 120 onto the substrate 110. The staggered arrangement of the first portion 1211 of the first sub-signal line 121 and the second portion 1222 of the second sub-signal line 122 in this embodiment makes the stress neutral surface 130 smoother and avoids stress concentration.

[0063] In the above embodiments, the contact surface between the substrate 110 and the sub-signal line 120 is described as a plane. In fact, in at least one embodiment of this disclosure, the contact surface between the substrate 110 and the sub-signal line 120 can be a curved surface. The following description, in conjunction with... Figures 9-10 An implementation of the contact surface of the substrate 110 and the sub-signal line 120 will be described.

[0064] Specifically, in at least one embodiment of this disclosure, the surface of the sub-signal line 120, which is composed of a plurality of first parts and a plurality of second parts, facing the substrate 110 is curved, and the surface away from the substrate 110 is planar. The surface of the substrate 110 facing the sub-signal line 120, which is composed of a plurality of first parts and a plurality of second parts, is conformal to the surface of the sub-signal line 120 facing the substrate 110.

[0065] By making the contact surface between the substrate 110 and the sub-signal line 120 curved, the contact area between the substrate 110 and the sub-signal line 120 can be increased, avoiding the concentration of bending stress on the contact surface that would cause the sub-signal line 120 to peel off from the substrate 110. This can improve the bending performance of the flexible circuit board 100 and ensure the reliability of the flexible circuit board 100.

[0066] Specifically, the fabrication process of the flexible circuit board 100 may include the following steps. First, a substrate 110 with at least a portion of its surface curved is provided, for example, by forming strip-shaped grooves of varying depths along the X-axis in a portion of a planar region of the substrate 110. Second, sub-signal lines 120 are formed in the strip-shaped grooves in a conformal manner, for example, by electroplating, chemical vapor deposition, or physical vapor deposition. Finally, the surface of the sub-signal lines 120 is planarized.

[0067] In at least one implementation, such as Figure 9 As shown, the flexible circuit board 100 and Figure 4 The difference in the flexible circuit board 100 in the illustrated embodiment is that the side of the first sub-signal line 121 facing the substrate 110 is curved, while the side facing away from the substrate 110 is flat. The specific structure of this flexible circuit board 100 can be found in the flexible circuit board 100 described in the above embodiments, and will not be repeated here.

[0068] In at least one implementation, such as Figure 10 As shown, the flexible circuit board 100 and Figure 7 The difference in the flexible circuit board 100 in the illustrated embodiment is that the side of the first sub-signal line 121 facing the substrate 110 is curved, and the side away from the substrate 110 is flat; the side of the second sub-signal line 122 facing the substrate 110 is curved, and the side away from the substrate 110 is flat. The specific structure of this flexible circuit board 100 can be referred to the flexible circuit board 100 in the above embodiments, and will not be repeated here.

[0069] In at least one implementation, such as Figure 11 As shown, the flexible circuit board 100 and Figure 8The difference in the flexible circuit board 100 in the illustrated embodiment is that the side of the first sub-signal line 121 facing the substrate 110 is curved, and the side away from the substrate 110 is flat; the side of the second sub-signal line 122 facing the substrate 110 is curved, and the side away from the substrate 110 is flat. The specific structure of this flexible circuit board 100 can be referred to the flexible circuit board 100 in the above embodiments, and will not be repeated here.

[0070] In the above embodiments, the curve is described using a broken line as an example. In fact, in at least one embodiment of this disclosure, the curve can be wavy. The following is in conjunction with... Figure 12 The structure of a flexible circuit panel with a wavy, curved shape is described.

[0071] In at least one implementation, such as Figure 12 As shown, the flexible circuit board 100 and Figure 4 The difference in the flexible circuit board 100 of the illustrated embodiment is that the curved surface on one side of the first sub-signal line 121 is wavy. The wavy surface on one side of the first sub-signal line 121 makes the stress neutral surface 130 smoother, avoids stress concentration, and thus improves the bending performance of the flexible circuit board 100.

[0072] In addition, you can refer to Figures 7-11 In the embodiment shown, the zigzag shape in the above embodiment is replaced with a wavy shape to make the stress neutral surface 130 smoother, avoid stress concentration, and thus improve the bending performance of the flexible circuit board 100.

[0073] To protect the flexible circuit board 100 and prevent the signal lines 120 from corrosion by water vapor and oxygen in the air, in at least one embodiment of this disclosure, such as Figure 13 As shown, encapsulation layers 140 can be provided on both sides of the flexible circuit board 100.

[0074] In the embodiments described above, the structure of the flexible circuit board 100 applied in a display device is used as an example for explanation. In reality, the above structure can also be applied to non-bending areas, and the structure of the flexible circuit board 100 can also be used in various electronic devices, such as flexible wearable devices. Furthermore, the flexible circuit board 100 can also be formed as a film layer in the driving circuit layer of a flexible display panel within the flexible display panel.

[0075] Figure 14 This is a top view of a display device provided in one embodiment of the present disclosure. Figure 15 For along Figure 14 A cross-sectional view along the CD line. At least one embodiment of this disclosure provides a display device, such as... Figure 14 and Figure 15As shown, the display device 300 comprises the flexible circuit board 100 and the display panel 200 as in the above embodiments.

[0076] The display device 300 further comprises a housing 301 and a cover plate 302, wherein the cover plate 302 is transparent, and the housing 301 and the cover plate 302 constitute a containing space in which the flexible circuit board 100 and the display panel 200 are arranged.

[0077] The display device 300 further comprises electronic elements such as a battery, a mainboard, and a camera 303. The housing 301 and the cover plate 302 are used to protect the electronic elements such as the flexible circuit board 100, the display panel 200, the battery, the mainboard, and the camera 303 arranged inside.

[0078] Specifically, the display device can be an electronic product such as a smart phone, a computer display, a game console, and a television.

[0079] The display device provided by the embodiments of the present disclosure and the flexible circuit board provided by the embodiments of the present disclosure belong to the same inventive concept, and have corresponding structures and beneficial effects. Details not described in detail in the embodiments of the display device can be referred to the embodiments of the flexible circuit board, which will not be described here.

[0080] The above only describes the preferred embodiments of the present disclosure and should not be used to limit the present disclosure. Any modifications, equivalent replacements, etc. made within the spirit and principle of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A flexible circuit board, characterized in that, The system includes: a substrate and at least one signal line. The signal line includes at least two sub-signal lines. Each sub-signal line includes a first sub-signal line and a second sub-signal line respectively disposed opposite to each other on both sides of the substrate. Both the first and second sub-signal lines include multiple first portions and multiple second portions. The first portions of the first and second sub-signal lines have the same thickness, and the second portions of the first and second sub-signal lines also have the same thickness. In each sub-signal line, the first and second portions are alternately arranged along the direction of the signal line and connected end to end. The thickness of the first portion is greater than the thickness of the second portion. The orthographic projection of the first portion of the first sub-signal line onto the substrate and the orthographic projection of the second portion of the second sub-signal line onto the substrate at least partially overlap. as well as The surfaces of the first sub-signal line and the second sub-signal line facing the substrate are curved, and the surfaces facing away from the substrate are planar. The surface of the substrate is conformal to the surface of the corresponding first sub-signal line and the second sub-signal line. In this configuration, the first part and the second part corresponding to each sub-signal line are in the same layer and made of the same material. The first sub-signal line and the second sub-signal line are made of the same material. When the thickness difference between the two is zero, the stress neutral surface coincides with the centerline of the substrate. When the thickness difference between the two is greater than zero and less than a predetermined threshold, the stress neutral surface is located in the substrate and close to the sub-signal line with greater thickness. When the thickness difference between the two is greater than the predetermined threshold, the stress neutral surface is located in the sub-signal line with greater thickness.

2. The flexible circuit board according to claim 1, characterized in that, The curved shape includes both polygonal and wavy shapes.

3. The flexible circuit board according to claim 1, characterized in that, The plurality of first portions and the plurality of second portions are located in the bending area of ​​the flexible circuit board.

4. A display device, characterized in that, include: Display panel; as well as The flexible circuit board as described in any one of claims 1-3 is bonded to the display panel.

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