Flexible circuit board and electronic device

Abstract

A flexible circuit board and an electronic device. The flexible circuit board has a first connection end (11), a second connection end (12), and a bending region (13) between the first connection end (11) and the second connection end (12); the bending region (13) comprises a flexible main body (21) and a reinforcement layer (22); the flexible main body (21) comprises a first bending region (131) close to the first connection end (11), a second bending region (132) close to the second connection end (12), and a middle region (133) located between the first bending region (131) and the second bending region (132); the reinforcement layer (22) is arranged on the surface of the flexible main body (21), and comprises a first reinforcement portion (221) located in the middle region (133) and second reinforcement portions (222) respectively located in the first bending region (131) and the second bending region (132), wherein the rigidity of the first reinforcement portion (221) is greater than the rigidity of the second reinforcement portion (222). The flexible circuit board has better bending performance and stability, and a narrow bezel design of an electronic device can be achieved.

Description

Flexible circuit board and electronic device

[0001] This application claims priority to Chinese Patent Application No. 202410831984.1, filed on June 25, 2024, the disclosure of which is incorporated herein in its entirety as part of the present application. TECHNICAL FIELD

[0002] Embodiments of the present disclosure relate to a flexible circuit board and an electronic device. BACKGROUND

[0003] Flexible Printed Circuit (FPC), also known as flexible circuit board or flexible circuit, is favored for its light weight, thin thickness, and free bending and folding. In some electronic devices, the flexible circuit board can be used as a connection circuit for electronic components and integrated circuits, so that the integrated circuits can control the working state of the electronic components. SUMMARY

[0004] At least one embodiment of the present disclosure provides a flexible circuit board having a first connection end, a second connection end, and a bending region between the first connection end and the second connection end, wherein the bending region includes a flexible main body and a reinforcing layer; the flexible main body includes a first bending region close to the first connection end, a second bending region close to the second connection end, and an intermediate region between the first bending region and the second bending region; the reinforcing layer is arranged on the surface of the flexible main body and includes a first reinforcing part in the intermediate region and a second reinforcing part in the first bending region and the second bending region, respectively, wherein the rigidity of the first reinforcing part is greater than the rigidity of the second reinforcing part.

[0005] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the first reinforcing part includes a first reinforcing sub-layer arranged on the surface of the flexible main body and located in the intermediate region, and the second reinforcing part includes a second reinforcing sub-layer arranged on the surface of the flexible main body and located in the first bending region and the second bending region.

[0006] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the average thickness of the second reinforcing sub-layer is less than the average thickness of the first reinforcing sub-layer.

[0007] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the thickness of the second reinforcing sub-layer gradually decreases in a direction away from the intermediate region.

[0008] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the first reinforcing portion further comprises a third reinforcing sublayer, the third reinforcing sublayer is arranged on the side of the first reinforcing sublayer away from the flexible main body, and the first reinforcing sublayer and the second reinforcing sublayer are made of the same material and are integrally connected.

[0009] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the thickness of the first reinforcing sublayer and the second reinforcing sublayer ranges from 0.01 mm to 0.15 mm, and the thickness of the third reinforcing sublayer ranges from 0.01 mm to 0.25 mm.

[0010] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the first bending area and the second bending area respectively have opposite first edge areas and second edge areas in the width direction of the bending area, and the second reinforcing sublayer is arranged in the first edge area and the second edge area.

[0011] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the first reinforcing sublayer and the second reinforcing sublayer are disconnected at the boundary between the first bending area and the intermediate area and the boundary between the second bending area and the intermediate area.

[0012] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the average thickness of the second reinforcing sublayer is 1 / 3 to 1 / 2 of the average thickness of the first reinforcing sublayer.

[0013] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the width of the bending area is C, the size of the first edge area and the second edge area in the width direction is d, and the shortest distance between the first edge area and the second edge area is e, then: e = C-2d, 0.5mm≤d≤1mm.

[0014] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the material of the first reinforcing sublayer is different from the material of the second reinforcing sublayer, and the rigidity of the material of the first reinforcing sublayer is greater than the rigidity of the material of the second reinforcing sublayer.

[0015] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the first reinforcing sublayer is made of a metal material or an organic material, and the second reinforcing sublayer is made of foam or ink.

[0016] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the material of the first reinforcing sublayer is the same as the material of the second reinforcing sublayer, and is a cured glue.

[0017] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the thickness of the second reinforcing sub-layer is less than the thickness of the first reinforcing sub-layer, and at the boundary between the first reinforcing sub-layer and the second reinforcing sub-layer, the cross section of the first reinforcing sub-layer and the second reinforcing sub-layer as a whole is in an arc shape or a stepped shape.

[0018] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the second reinforcing sub-layer comprises at least one hollow part.

[0019] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the second reinforcing sub-layer comprises a plurality of hollow parts, and the plurality of hollow parts are arranged along the length direction and the width direction of the bending area.

[0020] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the plurality of hollow parts are in a strip shape and extend along the width direction.

[0021] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the arrangement density of the plurality of hollow parts gradually increases or gradually decreases in the direction away from the middle area.

[0022] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the plurality of hollow parts are in a strip shape and extend along the width direction. The size of the plurality of hollow parts in the width direction of the bending area is c, the size of the plurality of hollow parts in the length direction of the bending area is a, the distance between adjacent two hollow parts in the width direction and the length direction is b, and the width of the bending area is C. Then, 0.5mm≤b≤1mm, 0.05mm≤a≤(2A-3b) / 3, and 0.5mm≤c≤C-b.

[0023] Wherein, A is the alignment tolerance, and A is 0.1mm-1.0mm.

[0024] At least one embodiment of the present disclosure provides an electronic device, which comprises a component and a flexible circuit board provided by an embodiment of the present disclosure. The bending area of the flexible circuit board is bent along the edge of the component, and the reinforcing layer is located on the surface of the flexible main body close to the component.

[0025] For example, in the electronic device provided by at least one embodiment of the present disclosure, the thickness of the component is B, the alignment tolerance between the flexible circuit board and the component is A, the length of the first bending area and the second bending area is the same, which is 2A, the length of the middle area is B-2A, and A is 0.1mm-1.0mm. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description only relate to some embodiments of the present disclosure and do not limit the present disclosure.

[0027] Fig. 1 is a schematic cross-sectional view of an electronic device;

[0028] Fig. 2 is a schematic enlarged view of the circled part of the electronic device in Fig. 1;

[0029] Fig. 3 is a schematic plan view of a flexible circuit board;

[0030] Fig. 4 is a schematic enlarged view of the circled part of the electronic device in Fig. 2;

[0031] Fig. 5 is a schematic plan view of a flexible circuit board provided by at least one embodiment of the present disclosure;

[0032] Fig. 6 is a schematic plan view of a bending area of a flexible circuit board provided by at least one embodiment of the present disclosure;

[0033] Fig. 7 is a schematic cross-sectional view of a bending area of a flexible circuit board provided by at least one embodiment of the present disclosure;

[0034] Fig. 8 is a schematic cross-sectional view of a bending area of a flexible circuit board provided by at least one embodiment of the present disclosure after bending;

[0035] Fig. 9 is another schematic cross-sectional view of a bending area of a flexible circuit board provided by at least one embodiment of the present disclosure;

[0036] Fig. 10 is still another schematic cross-sectional view of a bending area of a flexible circuit board provided by at least one embodiment of the present disclosure;

[0037] Fig. 11 is still another schematic cross-sectional view of a bending area of a flexible circuit board provided by at least one embodiment of the present disclosure;

[0038] Fig. 12 is a schematic plan view of a bending area of another flexible circuit board provided by at least one embodiment of the present disclosure;

[0039] Fig. 13 is a schematic cross-sectional view of a bending area of another flexible circuit board provided by at least one embodiment of the present disclosure;

[0040] Fig. 14 is another schematic cross-sectional view of a bending area of another flexible circuit board provided by at least one embodiment of the present disclosure;

[0041] Fig. 15 is a schematic cross-sectional view of a bending area of still another flexible circuit board provided by at least one embodiment of the present disclosure;

[0042] Fig. 16 is another schematic cross-sectional view of a bending area of still another flexible circuit board provided by at least one embodiment of the present disclosure;

[0043] FIGS. 17 and 18 are cross-sectional views of a bending region in another flexible circuit board during manufacturing, according to at least one embodiment of the present disclosure;

[0044] FIGS. 19-22 are plan views of a bending region in another flexible circuit board, according to at least one embodiment of the present disclosure;

[0045] FIG. 23 is a plan view of a hollowed-out portion in a bending region in another flexible circuit board, according to at least one embodiment of the present disclosure;

[0046] FIGS. 24 and 25 are cross-sectional views of a bending region in another flexible circuit board, according to at least one embodiment of the present disclosure; and

[0047] FIG. 26 is a cross-sectional view of alignment of a device and a flexible circuit board in an electronic device, according to at least one embodiment of the present disclosure. DETAILED DESCRIPTION

[0048] So that the objects, technical solutions and advantages of the embodiments of the present disclosure are more apparent, the technical solutions of the embodiments of the present disclosure will be described clearly and completely below with reference to the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are some but not all of the embodiments of the present disclosure. Based on the described embodiments of the present disclosure, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong within the scope of the present disclosure.

[0049] Unless otherwise defined, technical terms or scientific terms used in the present disclosure shall have the ordinary meaning commonly understood by one of ordinary skill in the art to which the present disclosure belongs. The terms "first", "second", and similar terms used in the present disclosure do not necessarily denote any order, quantity, or importance, but are used to distinguish different components. The terms "include", "contain", and similar terms mean that the elements or objects before the terms encompass the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms "connected" or "linked" and similar terms do not necessarily mean physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right", and the like are used only to indicate relative positional relationships, and when the absolute positions of the described objects are changed, the relative positional relationships can also be changed accordingly.

[0050] FIG. 1 is a schematic cross-sectional view of an electronic device, taken as an example of a display device, as shown in FIG. 1, the electronic device includes a cover plate 1, an optical adhesive 2, a polarizer 3, a display panel 4, a heat dissipation layer 5, a flexible circuit board 6, and an integrated circuit 7, and the like. One side of the flexible circuit board 6 is electrically connected to the display panel 4, for example, by bonding, and the other side is electrically connected to the integrated circuit 7, for example, by a B2B connector or a ZIF connector, thereby realizing the electrical connection of the integrated circuit 7→ the flexible circuit board 6→ the display panel 4.

[0051] The part where the flexible circuit board 6 is connected to the integrated circuit 7 usually needs to be bent once or more times to realize electrical connection. For example, FIG. 2 shows an enlarged schematic view of the circled part in FIG. 1, as shown in FIGS. 1 and 2, the flexible circuit board 6 needs to be bent by 180° to electrically connect the integrated circuit 7 to the display panel 4. In order to facilitate bending and save space, the bending part is usually elongated. For example, FIG. 3 shows a plan view of the flexible circuit board 6, as shown in FIG. 3, the bending part 61 is elongated.

[0052] In some embodiments, in order to realize the thinness of the product, as shown in FIG. 2, some components 8 are often placed inside and outside the bending part 61. As shown in FIG. 3, the bending part 61 is provided with a silk screen line 9, which can play a role in visually judging the accuracy of the bending position.

[0053] As shown in FIG. 2, when the flexible circuit board 6 is in a bent state, the bending radius is large, occupying a space with a length L, FIG. 4 shows an enlarged schematic view of the circled part in FIG. 2, as shown in FIG. 4, the bending part 61 contacts the component 8 at the edge of the component 8, as shown in the circled part in FIG. 4, which causes the surface of the flexible circuit board 6 to be easily scratched by the component 8, and even the circuit to be broken, affecting the normal work of the electronic device.

[0054] At least one embodiment of the present disclosure provides a flexible circuit board and an electronic device, the flexible circuit board has a first connection end, a second connection end, and a bending region between the first connection end and the second connection end, the bending region includes a flexible main body and a reinforcing layer; the flexible main body includes a first bending region close to the first connection end, a second bending region close to the second connection end, and an intermediate region between the first bending region and the second bending region; the reinforcing layer is arranged on the surface of the flexible main body and includes a first reinforcing part in the intermediate region and a second reinforcing part in the first bending region and the second bending region, respectively, wherein the rigidity of the first reinforcing part is greater than the rigidity of the second reinforcing part.

[0055] The flexible circuit board provided by at least one of the embodiments of the present disclosure has the reinforcing layer arranged in the bending area, so that the bending area is prevented from being scratched by components after bending, and the structure of the bending area is protected. In addition, the rigidity of the first reinforcing part in the middle area is greater than the rigidity of the second reinforcing part in the first bending area and the second bending area located on both sides of the middle area, so that the bending curvature of the bending area in the middle area is reduced, and the space occupied by the bending area after bending is reduced, so as to realize the narrow frame design.

[0056] The flexible circuit board and the electronic device provided by the embodiments of the present disclosure are described below through several specific embodiments.

[0057] The present disclosure provides a flexible circuit board, as shown in FIG. 5, which is a schematic plan view of the flexible circuit board, FIG. 6 is a schematic plan view of a bending area of the flexible circuit board, FIG. 7 is a schematic cross-sectional view of the bending area of the flexible circuit board, and FIG. 8 is a schematic cross-sectional view of the bending area of the flexible circuit board after bending. As shown in FIG. 5, the flexible circuit board has a first connecting end 11, a second connecting end 12, and a bending area 13 between the first connecting end 11 and the second connecting end 12.

[0058] For example, the first connecting end 11 has a connector such as a B2B connector or a ZIF connector, so as to electrically connect the flexible circuit board with an integrated circuit or other control device. The second connecting end 12 has a binding circuit, so as to electrically connect the flexible circuit board with an electronic device, such as a display panel. The bending area 13 can be bent, for example, by 180°, so as to stack two devices connected by the flexible circuit board, and realize the narrow frame design. For example, in other embodiments, the connection modes of the first connecting end 11 and the second connecting end 12 can be interchanged, and the embodiments of the present disclosure do not make specific limitations in this regard.

[0059] As shown in FIG. 6 and FIG. 7, the bending area 13 includes a flexible main body 21 and a reinforcing layer 22. In combination with FIG. 5-FIG. 7, the flexible main body 21 includes a first bending area 131 close to the first connecting end 11, a second bending area 132 close to the second connecting end 12, and a middle area 133 between the first bending area 131 and the second bending area 132. The reinforcing layer 22 is arranged on the surface of the flexible main body 21, and includes a first reinforcing part 221 in the middle area 133 and a second reinforcing part 222 in the first bending area 131 and the second bending area 132, respectively. The rigidity of the first reinforcing part 221 is greater than the rigidity of the second reinforcing part 222.

[0060] Thus, the bending area 13 is provided with the reinforcing layer 22, after the bending area 13 is bent, as shown in FIG. 8, the bending area 13 can be prevented from being scratched by the component 8, and the structure of the bending area 13 is protected; in addition, the rigidity of the first reinforcing part 221 of the middle area 133 is greater than the rigidity of the second reinforcing part 222 in the first bending area 131 and the second bending area 132 on both sides of the middle area 133, so that the bending curvature of the bending area 13 (for example, the middle area 133) can be reduced, and the space L occupied by the bending area 13 after bending is reduced, so as to realize the narrow frame design.

[0061] For example, in some embodiments, the flexible body 21 includes a flexible substrate and a circuit pattern and a packaging layer and other structures arranged on the flexible substrate, and specific reference can be made to related technologies. At this time, the reinforcing layer 22 can be an additional structure attached to the inner surface of the flexible body 21 (i.e. the inner surface after bending, such as the left surface shown in FIG. 8), for example, an additional structure attached to one side of the flexible substrate, or an additional structure attached to one side of the packaging layer, so as not to affect the overall structure of the flexible circuit board and the original preparation process.

[0062] For example, the bending area 13 is long strip-shaped, as shown in FIG. 6, the length direction of the bending area 13 is along the horizontal direction in the drawing, and the width direction is along the vertical direction in the drawing. For example, when the bending area 13 is bent, the bending axis is along the width direction, thereby forming the bending shown in FIG. 8.

[0063] For example, in some embodiments, the structures of the first reinforcing part 221 and the second reinforcing part 222 are different, for example, the arrangement range is different, the thickness is different, the material is different, the pattern is different, etc., so that the rigidity of the first reinforcing part 221 is greater than the rigidity of the second reinforcing part 222.

[0064] For example, in some embodiments, the thickness of the first reinforcing part 221 can be 0.02mm-0.40mm, such as 0.02mm, 0.05mm, 0.10mm, 0.15mm, 0.20mm, 0.25mm, 0.30mm, 0.35mm or 0.40mm, etc., and the thickness of the second reinforcing part 222 can be 0.01mm-0.15mm, such as 0.02mm, 0.04mm, 0.06mm, 0.08mm, 0.10mm, 0.12mm, 0.13mm or 0.15mm, etc.

[0065] For example, in some embodiments, as shown in FIG. 7, the first reinforcing portion 221 includes a first reinforcing sub-layer 31 arranged on the surface of the flexible main body 21 at the middle region 133, and the second reinforcing portion 222 includes a second reinforcing sub-layer 32 also arranged on the surface of the flexible main body 21 at the first bending region 131 and the second bending region 132.

[0066] For example, in some embodiments, the average thickness of the second reinforcing sub-layer 32 is less than the average thickness of the first reinforcing sub-layer 31.

[0067] In the embodiments of the present disclosure, the thickness of a structure refers to the dimension of the structure in the direction perpendicular to the surface of the flexible main body 21, i.e., the dimension in the vertical direction in FIG. 7, and the average thickness of a structure refers to the average value of the thickness of the structure at each position in the arrangement region thereof.

[0068] For example, in some embodiments, as shown in FIG. 9, the first reinforcing sub-layer 31 has a uniform thickness (i.e., an equal-thickness design) at the middle region 133, i.e., a first thickness, and the second reinforcing sub-layer 32 has a uniform thickness at the first bending region 131 and the second bending region 132, i.e., a second thickness, and the first thickness is greater than the second thickness; or, in other embodiments, the thickness of the second reinforcing sub-layer 32 gradually decreases in the direction away from the middle region 133, for example, as shown in FIG. 7, the thickness of the second reinforcing sub-layer 32 gradually decreases, and the cross section presents an arc shape to achieve a smooth transition; or, as shown in FIG. 10, the thickness of the second reinforcing sub-layer 32 decreases in a stepped manner in the direction away from the middle region 133, and the cross section presents a stepped shape.

[0069] Thus, the rigidity of the first reinforcing sub-layer 31 is greater than the rigidity of the second reinforcing sub-layer 32. After the bending region 13 is bent, the second reinforcing sub-layer 32 can avoid the bending region 13 being scratched by the component 8 at the first bending region 131 and the second bending region 132, thereby achieving the effect of protecting the structure of the bending region 13; the first reinforcing sub-layer 31 has greater rigidity at the middle region 133, thereby reducing the bending curvature of the bending region 13 (e.g., the middle region 133), and further reducing the space L occupied by the bending region 13 after bending, so as to facilitate the realization of a narrow frame design.

[0070] For example, in other embodiments, as shown in FIG. 11, the first reinforcing portion 221 can further include more reinforcing sub-layers, such as a third reinforcing sub-layer 33 arranged on the side of the first reinforcing sub-layer 31 away from the flexible main body 21, and at this time, the first reinforcing sub-layer 31 and the second reinforcing sub-layer 32 can be made of the same material and integrally connected. Thus, the first reinforcing portion 221 has more reinforcing sub-layers to have greater rigidity.

[0071] For example, in the embodiment of FIG. 11, the thickness (i.e., the dimension in the vertical direction in the figure) of the first and second reinforcing sub-layers 31 and 33 ranges from 0.01 mm to 0.15 mm, such as 0.01 mm, 0.03 mm, 0.05 mm, 0.08 mm, 0.10 mm, 0.12 mm, or 0.15 mm, etc.; and the thickness of the third reinforcing sub-layer 33 ranges from 0.01 mm to 0.25 mm, such as 0.01 mm, 0.03 mm, 0.05 mm, 0.08 mm, 0.10 mm, 0.12 mm, 0.15 mm, 0.18 mm, 0.20 mm, 0.22 mm, or 0.25 mm, etc.

[0072] For example, for small- and medium-sized products such as watches, cell phones, and the like, and for medium-sized products such as tablets, notebook computers, and the like, the thickness of the first and second reinforcing sub-layers 31 and 33 ranges from 0.01 mm to 0.10 mm, and the thickness of the third reinforcing sub-layer 33 ranges from 0.01 mm to 0.20 mm, such as 0.01 mm, 0.03 mm, 0.05 mm, 0.08 mm, 0.10 mm, 0.12 mm, 0.15 mm, 0.18 mm, or 0.20 mm, etc.; for example, for large- and medium-sized products such as televisions, monitors, and the like, the thickness of the first and second reinforcing sub-layers 31 and 33 ranges from 0.03 mm to 0.15 mm, such as 0.03 mm, 0.05 mm, 0.08 mm, 0.10 mm, 0.12 mm, or 0.15 mm, etc.; and the thickness of the third reinforcing sub-layer 33 ranges from 0.03 mm to 0.25 mm, such as 0.03 mm, 0.05 mm, 0.08 mm, 0.10 mm, 0.12 mm, 0.15 mm, 0.18 mm, 0.20 mm, 0.22 mm, or 0.25 mm, etc.

[0073] For example, in some embodiments, the first reinforcing sub-layer 31, the second reinforcing sub-layer 32 and the third reinforcing sub-layer 33 are an integral structure, for example, in the manufacturing process, the first reinforcing sub-layer 31, the second reinforcing sub-layer 32 and the third reinforcing sub-layer 33 are integrally formed, and then the part of the integrally formed reinforcing material located at the first bending area 131 and the second bending area 132 is subjected to groove processing to obtain the integral first reinforcing sub-layer 31, the second reinforcing sub-layer 32 and the third reinforcing sub-layer 33. At this time, in the middle area 133, the thickness of the first reinforcing sub-layer 31 and the third reinforcing sub-layer 33 can be 0.02mm-0.40mm, such as 0.02mm, 0.05mm, 0.10mm, 0.15mm, 0.20mm, 0.25mm, 0.30mm, 0.35mm or 0.40mm, etc.; in the first bending area 131 and the second bending area 132, the thickness of the second reinforcing sub-layer 32 can be 0.01mm-0.15mm, such as 0.02mm, 0.04mm, 0.06mm, 0.08mm, 0.10mm, 0.12mm, 0.13mm or 0.15mm, etc.

[0074] Alternatively, in other embodiments, the second reinforcing portion 222 can also include a plurality of reinforcing sub-layers, but the number of the plurality of reinforcing sub-layers included in the second reinforcing portion is less than the number of the plurality of reinforcing sub-layers included in the first reinforcing portion 221, so that the rigidity of the first reinforcing portion 221 is greater than the rigidity of the second reinforcing portion 222.

[0075] For example, in the embodiments of FIGS. 7 and 9-10, the materials of the first reinforcing sub-layer 31 and the second reinforcing sub-layer 32 can be the same or different, as long as the rigidity of the first reinforcing portion 221 is greater than the rigidity of the second reinforcing portion 222. For example, in other embodiments, the thickness of the first reinforcing portion 221 and the second reinforcing portion can also be the same, but have different materials respectively, so that the rigidity of the first reinforcing portion 221 is greater than the rigidity of the second reinforcing portion 222.

[0076] For example, in some embodiments, the first reinforcing sub-layer 31 and the second reinforcing sub-layer 32 can adopt an organic insulating material, such as polyethylene terephthalate (PET) or the like, which has a certain rigidity. In the first bending area 131 and the second bending area 132, it can play a role in blocking the sharp corners of the component 8 and the surface of the flexible circuit board, avoiding direct contact between the two, so as to protect the flexible circuit board from damage; in the middle area 133, it plays a supporting role, so that the middle area 133 is approximately straight after bending, reducing the bending curvature, thereby saving assembly space, as shown in FIG. 8.

[0077] For example, in the embodiment of FIG. 11, the material of the third reinforcing sub-layer 33 can be the same as the material of the first reinforcing sub-layer 31 and the second reinforcing sub-layer 32, thereby thickening the thickness of the first reinforcing portion 221 of the intermediate region 133 to improve the rigidity thereof. Alternatively, in other embodiments, the material of the third reinforcing sub-layer 33 can also be other organic material or metal material to improve the rigidity of the first reinforcing portion 221.

[0078] For example, FIG. 12 shows a plan view of another bending region of a flexible substrate according to at least one embodiment of the present disclosure. In other embodiments, as shown in FIG. 12, the first bending region 131 and the second bending region 132 each have a first edge region 134 and a second edge region 135 opposite to each other in the width direction of the bending region 13 (vertical direction in the figure), and the second reinforcing sub-layer 32 is arranged in the first edge region 134 and the second edge region 135, but not arranged in the region between the first edge region 134 and the second edge region 135. At this time, the second reinforcing sub-layer 32 is hollowed in the intermediate portion of the first bending region 131 and the second bending region 132, thereby reducing the rigidity of the second reinforcing sub-layer 32.

[0079] For example, at the boundary between the first bending region 131 and the intermediate region 133 and the boundary between the second bending region 132 and the intermediate region 133, the first reinforcing sub-layer 31 and the second reinforcing sub-layer 32 are disconnected, i.e., the first reinforcing sub-layer 31 and the second reinforcing sub-layer 32 are not connected together. For example, during the manufacturing process, a cutting line can be made at the boundary between the first bending region 131 and the intermediate region 133 and the boundary between the second bending region 132 and the intermediate region 133 to improve the bending effect.

[0080] For example, in some embodiments, the average thickness of the second reinforcing sub-layer 32 is 1 / 3 to 1 / 2 of the average thickness of the first reinforcing sub-layer 31, such as 1 / 3, 3 / 8, 5 / 12, 13 / 24 or 1 / 2, etc. For example, as shown in FIG. 13, the second reinforcing sub-layer 32 can have a uniform thickness (i.e., using an equal thickness design) in the first edge region 134 and the second edge region 135, which is a third thickness, and a uniform thickness in the intermediate region 133, which is a first thickness, the third thickness being smaller than the first thickness, for example, the third thickness being 1 / 3 to 1 / 2 of the first thickness, such as 1 / 3, 3 / 8, 5 / 12, 13 / 24 or 1 / 2, etc. Alternatively, as shown in FIG. 14, the thickness of the second reinforcing sub-layer 32 gradually decreases in the direction away from the intermediate region 133, for example, the cross section of the second reinforcing sub-layer 32 presents an arc shape, thereby achieving a smooth transition. Alternatively, referring to FIG. 10, the thickness of the second reinforcing sub-layer 32 decreases in a stepped manner in the direction away from the intermediate region 133, and the cross section presents a stepped shape.

[0081] For example, in some embodiments, as shown in FIG. 12, the width of the bending region 13 is C, the size of the first edge region 134 and the second edge region 435 in the width direction of the bending region 13 is d, the shortest distance between the first edge region 134 and the second edge region 135 is e, considering the cutting and fitting process, d≥0.5mm, at the same time, in order to reduce the rigidity of the first bending region 131 and the second bending region 132 as much as possible, it is recommended that d be less than or equal to 1mm, then: e=C-2d, 0.5mm≤d≤1mm.

[0082] The above design fully considers the feasibility of the preparation process and the rigidity design of the second reinforcing sub-layer 32 and the first reinforcing sub-layer 31, while improving the preparation yield of the light-emitting unit and the product reliability.

[0083] For example, in the embodiments of FIGS. 12-14, the materials of the first reinforcing sub-layer 31 and the second reinforcing sub-layer 32 can be the same or different.

[0084] For example, corresponding to the arrangement of FIG. 6 or FIG. 12, the material of the first reinforcing sub-layer 31 and the material of the second reinforcing sub-layer 32 can be different, so that the rigidity of the material of the first reinforcing sub-layer 31 is greater than the rigidity of the material of the second reinforcing sub-layer 32 by selecting the material. For example, the first reinforcing sub-layer 31 can be selected from hard materials such as metal materials, alloy materials or organic materials, etc., such as stainless steel or PET, etc., and the second reinforcing sub-layer 32 can be selected from soft materials such as foam or ink, etc., for example, the ink can be photosensitive anti-soldering ink, etc. Thus, the first reinforcing sub-layer 31 can have greater rigidity, thereby realizing smaller bending curvature, thereby reducing the occupied space L, and at the same time, the second reinforcing sub-layer 32 can have smaller rigidity, realizing the protection effect, avoiding scratching the flexible circuit board.

[0085] For example, in the case where the material of the first reinforcing sub-layer 31 and the material of the second reinforcing sub-layer 32 are different, as shown in FIG. 15, the thickness of the first reinforcing sub-layer 31 can be equal to the thickness of the second reinforcing sub-layer 32; or, as shown in FIG. 16, the average thickness of the first reinforcing sub-layer 31 can be greater than the average thickness of the second reinforcing sub-layer 32; at this time, the first reinforcing sub-layer 31 and the second reinforcing sub-layer 32 can adopt uniform thickness design (refer to FIG. 13, equal thickness design), or, in the direction away from the middle region 133, the thickness of the second reinforcing sub-layer 32 gradually decreases, for example, the cross section of the second reinforcing sub-layer 32 presents an arc shape, realizing smooth transition; or, referring to FIG. 10, in the direction away from the middle region 133, the thickness of the second reinforcing sub-layer 32 decreases in steps, and the cross section presents a stepped shape.

[0086] For example, in some other embodiments, corresponding to the arrangement of Fig. 6 or Fig. 12, the material of the first reinforcing sub-layer 31 can be the same as the material of the second reinforcing sub-layer 32, such as an organic insulating material, for example, a thermosetting glue or a light-cured glue (for example, a UV-cured glue). The glue is a viscous soft material before curing, and is cured after being heated or lighted, so as to increase the rigidity.

[0087] For example, the thickness of the second reinforcing sub-layer 32 can be less than the thickness of the first reinforcing sub-layer 31, and at the boundary between the first reinforcing sub-layer 31 and the second reinforcing sub-layer 32, the cross section of the first reinforcing sub-layer 31 and the second reinforcing sub-layer 32 can be arc-shaped or stepped, or be oblique. For example, the bending arc of the arc shape can be towards the flexible circuit board (in the form shown in the figure), or can be away from the flexible circuit board, and the embodiments of the present disclosure do not make specific limitations thereon. Thus, in the first bending area 131 and the second bending area 132, the thickness of the cured glue is thin, and after curing, the rigidity can still be low, so as to avoid scratching of the flexible circuit board, and the thickness of the cured glue in the middle area 133 is large, and has high rigidity, so as to reduce the bending arc and reduce the occupied space.

[0088] For example, in the preparation process, different thicknesses of the cured glue can be made by controlling the parameters such as the number of glue coating layers, the glue discharge pressure, and the glue discharge speed. For example, on the basis of the above parameters, the coating mode of the starting and ending positions of the middle area 133 can be controlled, so that the transition area presents different shapes.

[0089] For example, as shown in Fig. 17, a plurality of layers of the cured glue can be coated in the middle area 133 to form the first reinforcing sub-layer 31, and a single layer or a plurality of layers of the cured glue with a number less than that of the middle area 133 can be coated in the first bending area 131 and the second bending area 132 to form the second reinforcing sub-layer 32. When a plurality of layers of the cured glue are coated in the middle area 133, if the starting and ending positions of each layer of glue are the same or close to each other, an arc shape is finally formed at the boundary between the first reinforcing sub-layer 31 and the second reinforcing sub-layer 32 due to the natural flow of the cured glue. Thus, by the above process, the thickness of the first reinforcing sub-layer 31 is greater than the thickness of the second reinforcing sub-layer 32, and when the cured glue is cured, a smooth transition is formed at the boundary between the first reinforcing sub-layer 31 and the second reinforcing sub-layer 32, so as to form an arc-shaped cross section, as shown in the circle in Fig. 17.

[0090] Alternatively, as shown in FIG. 18, the starting and ending positions of the multi-layered solidified glue coated in the middle region 133 do not coincide, but in each adjacent two layers, the previous layer is recessed relative to the next layer, that is, the starting and ending positions of the glue coating have a certain interval, so that after solidification, a stepped transition is formed at the junction of the first and second reinforcing sub-layers 31 and 32, thereby forming a stepped cross-section, as shown in the circle in FIG. 18.

[0091] For example, FIG. 19 shows a plan view of another flexible circuit board according to at least one embodiment of the present disclosure. As shown in FIG. 19, the second reinforcing sub-layer 32 includes at least one hollow portion H, for example, a plurality of hollow portions H. For example, the plurality of hollow portions H are arranged along the length direction (horizontal direction in the figure) and width direction (vertical direction in the figure) of the bending region 13, for example, can be arranged as multiple rows and multiple columns, one row and multiple columns, or multiple rows and one column, etc. The arrangement of the hollow portions H can reduce the rigidity of the second reinforcing sub-layer 32, so as to have better bending performance, and at the same time can prevent the flexible circuit board from being scratched. For example, the hollow portions H can make the first and second bending regions 131 and 132 function like hinges, which is conducive to smooth bending at the corners of the component 8.

[0092] For example, in some embodiments, the plurality of hollow portions H are long strips, for example, ellipses, tracks, or H-shaped, etc., which extend along the width direction of the bending region 13, thereby conforming to the bending of the bending region 13 and achieving better bending effect. For example, in other embodiments, the plurality of hollow portions H can also be circular, square, or other suitable shapes, and the embodiments of the present disclosure do not make specific limitations in this regard.

[0093] For example, in some embodiments, the plurality of hollow portions H can be uniformly arranged, aligned arranged, or staggered arranged. For example, as shown in FIG. 19, the plurality of hollow portions H are aligned arranged along the row direction and column direction, and are uniformly arranged; or as shown in FIG. 20, the plurality of hollow portions H are aligned arranged along the row direction and staggered arranged along the column direction, and the plurality of hollow portions H are uniformly arranged as a whole; or as shown in FIG. 21, in some embodiments, the arrangement density of the plurality of hollow portions H gradually decreases in the direction away from the middle region 133; or as shown in FIG. 22, in some embodiments, the arrangement density of the plurality of hollow portions H gradually increases in the direction away from the middle region 133. For example, in the embodiments of FIGS. 21 and 22, the arrangement manner of the plurality of hollow portions H in the first and second bending regions 131 and 132 is symmetrical, so that the first and second bending regions 131 and 132 have substantially the same bending effect on both sides of the middle region 133.

[0094] For example, in some embodiments, as shown in FIG. 23, the spacing of two adjacent hollows H in the width direction and the length direction of the bending area 13 is b, taking into account the cutting process and the bending effect, the hollow spacing b is in the range of 0.5mm≤b≤1.0mm, for example, b is 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1.0mm, etc.; the size of the plurality of hollows H in the length direction of the bending area 13 is a, considering the cutting process, a≥0.5mm, for example, a is 0.5mm, 0.6mm, 0.7mm, 0.8mm or 0.9mm, etc.; considering the bending effect, in order to make the first bending area 131 and the second bending area 132 better realize the effect of the hinge, the hollow H at least has 3 columns, then the maximum value of a needs to satisfy (a+b)*3=2A; the size of the plurality of hollows H in the width direction of the bending area 13 is c, considering the cutting process, c≥0.5mm, for example, c is 0.5mm, 0.6mm, 0.7mm, 0.8mm or 0.9mm, etc.; considering the bending effect, the hollow H at least has 1 row, as shown in FIG. 19, the width of the bending area 13 is C, then the maximum value of c needs to satisfy c+b=C, that is, c≤C-b; then: 0.5mm≤b≤1mm, 0.05mm≤a≤(2A-3b) / 3, 0.5mm≤c≤C-b,

[0095] Wherein, A is the alignment tolerance, for example, the alignment tolerance between the bending area 13 and the part 8 is 0.1mm~1.0mm, for example, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1.0mm, etc. Through the above size design, the feasibility of the preparation process and the stability and bending shape of the product obtained can be considered at the same time, and the bending effect and the preparation yield of the flexible circuit board are improved.

[0096] For example, in the above embodiment, the thickness of the first reinforcing sub-layer 31 and the second reinforcing sub-layer 32 can be the same, part of the material of the second reinforcing sub-layer 32 is removed to form a plurality of hollows H, for example, in some examples, the hollow H can penetrate the second reinforcing sub-layer 32, or, in some examples, the hollow H can also not penetrate the second reinforcing sub-layer 32, as shown in FIG. 24.

[0097] For example, in the above embodiment, the thickness of the first reinforcing sub-layer 31 and the second reinforcing sub-layer 32 can also be different, as shown in FIG. 25, the hollow H can penetrate the second reinforcing sub-layer 32, or, in other examples, the hollow H can also not penetrate the second reinforcing sub-layer 32, the embodiment of the present disclosure does not make specific limitation thereto.

[0098] For example, in the above embodiment, the sizes and shapes of the plurality of hollows H are the same, so that the performance of the second reinforcing sub-layer 32 at each position of the first bending region 131 and the second bending region 132 is substantially uniform, to ensure uniform stress during bending and improve the reliability of the bending region 13. In other embodiments, the sizes and shapes of the plurality of hollows H can also be designed to be different, as long as the same technical effect can be achieved.

[0099] At least one embodiment of the present disclosure also provides an electronic device, as shown in FIG. 8 and FIG. 26, which includes a device 8 and a flexible circuit board provided by an embodiment of the present disclosure. The bending region 13 of the flexible circuit board is bent along the edge of the device 8. After bending, the reinforcing layer 22 is located on the surface of the flexible main body 21 close to the device 8, thereby protecting the bending region 13 from being damaged by the device 8.

[0100] For example, in order to better exert the supporting effect of the middle region 133 and make the flexible circuit board as close to a straight line as possible in the middle region 133, the middle region 133 needs to be as long as possible on the premise of ensuring that it does not contact the corners of the device 8. As shown in FIG. 26, considering various assembly tolerances, the alignment tolerance of the flexible circuit board and the device 8 is A, and the thickness of the device 8 is B. In order to make the corners of the device 8 fully located in the first bending region 131 and the second bending region 132, avoid deviating from the first bending region 131 and the second bending region 132 due to alignment errors, and at the same time avoid the length of the first bending region 131 and the second bending region 132 being too long, the length of the first bending region 131 and the second bending region 132 (i.e. the size along the length direction of the bending region 13) is the same, which is 2A, and the length of the middle region 133 is B-2A. A is usually 0.1mm-1.0mm, such as 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or 1.0mm, etc.

[0101] For example, for small and medium-sized products such as wearable watches or mobile phones, A can be 0.5mm, so the length of the first bending region 131 and the second bending region 132 is about 1.0mm, and the length of the middle support region is about B-2.0mm. For example, for medium-sized products such as tablets and notebook computers, A can be about 0.7mm, so the length of the first bending region 131 and the second bending region 132 is about 1.4mm, and the length of the middle support region is about B-1.4mm. For example, for large-sized products such as televisions and displays, A can be about 1.0mm, so the length of the first bending region 131 and the second bending region 132 is about 2.0mm, and the length of the middle support region is about B-2.0mm.

[0102] Thus, the first bending area 131 and the second bending area 132 of the flexible circuit board can fully correspond to the corner positions of the device 8, so that the second reinforcing sub-layer 32 can achieve the isolation and protection effect, the middle area 133 corresponds to the side edge of the device 8, and a straight line or a nearly straight line is achieved, so as to reduce the space occupied by the bending, and facilitate the narrow frame design.

[0103] For example, the electronic device provided by the embodiment of the present disclosure can be a display device, such as an OLED display device or an LCD display device, and at this time, the device 8 can be an OLED display panel or an LCD display panel, and the display device can be a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator, or any product or component having a display function.

[0104] The following points also need to be explained:

[0105] (1) The drawings of the embodiment of the present disclosure only involve the structures involved in the embodiment of the present disclosure, and other structures can be referred to the general design.

[0106] (2) In order to be clear, the thickness of the layer or area is enlarged or reduced in the drawings used to describe the embodiments of the present disclosure, that is, the drawings are not drawn according to the actual proportion. It can be understood that when an element such as a layer, a film, an area or a substrate is referred to as being located “on” or “under” another element, the element can be “directly” located on or under another element or there can be an intermediate element.

[0107] (3) In the case of no conflict, the embodiments of the present disclosure and the features in the embodiments can be combined with each other to obtain new embodiments.

[0108] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A flexible circuit board having a first connecting end, a second connecting end, and a bending region between the first connecting end and the second connecting end, wherein, The bending area includes: The flexible body includes a first bending region near the first connecting end, a second bending region near the second connecting end, and an intermediate region located between the first bending region and the second bending region. A reinforcing layer is disposed on the surface of the flexible body, including a first reinforcing portion located in the intermediate region and second reinforcing portions located in the first bending region and the second bending region, respectively. The stiffness of the first reinforced part is greater than that of the second reinforced part.

2. The flexible circuit board according to claim 1, wherein, The first reinforcing portion includes a first reinforcing sublayer, which is disposed on the surface of the flexible body and located in the middle region. The second reinforcing portion includes a second reinforcing sublayer disposed on the surface of the flexible body, located in the first bending region and the second bending region.

3. The flexible circuit board according to claim 2, wherein, The average thickness of the second reinforcing sublayer is less than the average thickness of the first reinforcing sublayer.

4. The flexible circuit board according to claim 3, wherein, The thickness of the second reinforcing sublayer gradually decreases in the direction away from the central region.

5. The flexible circuit board according to claim 2, wherein, The first reinforcing portion further includes a third reinforcing sublayer, which is disposed on the side of the first reinforcing sublayer away from the flexible body. The first reinforcing sublayer and the second reinforcing sublayer are made of the same material and are integrally connected.

6. The flexible circuit board according to claim 5, wherein, The thickness of the first reinforcing sublayer and the second reinforcing sublayer ranges from 0.01 mm to 0.15 mm. The thickness of the third reinforcing sublayer ranges from 0.01 mm to 0.25 mm.

7. The flexible circuit board according to claim 2, wherein, The first bending region and the second bending region have opposing first edge regions and second edge regions in the width direction of the bending region, respectively, and the second reinforcing sublayer is disposed in the first edge region and the second edge region.

8. The flexible circuit board according to claim 7, wherein, At the boundaries of the first bending region and the intermediate region, and at the boundaries of the second bending region and the intermediate region, the first reinforcing sublayer and the second reinforcing sublayer are disconnected.

9. The flexible circuit board according to claim 7 or 8, wherein, The average thickness of the second reinforcing sublayer is 1 / 3 to 1 / 2 of the average thickness of the first reinforcing sublayer.

10. The flexible circuit board according to any one of claims 7-9, wherein, The width of the bent area is C, the dimensions of the first edge area and the second edge area in the width direction are d, and the shortest distance between the first edge area and the second edge area is e. Then: e = C - 2d, 0.5mm ≤ d ≤ 1mm.

11. The flexible circuit board according to claim 2, wherein, The material of the first reinforcing sublayer is different from the material of the second reinforcing sublayer. The stiffness of the material in the first reinforcing sublayer is greater than that of the material in the second reinforcing sublayer.

12. The flexible circuit board according to claim 11, wherein, The first reinforcing sublayer is made of metallic or organic materials; The second reinforcing sublayer is made of foam or ink.

13. The flexible circuit board according to claim 2, wherein, The material of the first reinforcing sublayer is the same as that of the second reinforcing sublayer, which is a cured adhesive.

14. The flexible circuit board according to claim 13, wherein, The thickness of the second reinforcing sublayer is less than that of the first reinforcing sublayer, and at the boundary between the first and second reinforcing sublayers, the cross-sections of the first and second reinforcing sublayers are generally arc-shaped or stepped.

15. The flexible circuit board according to claim 2, wherein, The second reinforcing sublayer includes at least one hollow portion.

16. The flexible circuit board according to claim 2, wherein, The second reinforcing sublayer includes multiple hollow sections, which are arranged along the length and width directions of the bending region.

17. The flexible circuit board according to claim 16, wherein, The plurality of hollowed-out sections are elongated and extend along the width direction.

18. The flexible circuit board according to claim 16 or 17, wherein, In the direction away from the central region, the arrangement density of the plurality of hollowed-out portions gradually increases or decreases.

19. The flexible circuit board according to claim 16 or 17, wherein, The dimensions of the plurality of hollowed-out portions in the width direction of the bending area are c, and the dimensions in the length direction of the bending area are a. The distance between two adjacent hollowed-out portions in the width and length directions is b. The width of the bending area is C. Then: 0.5mm≤b≤1mm, 0.05mm≤a≤(2A-3b) / 3, 0.5mm≤c≤Cb. Where A is the alignment tolerance, which is 0.1mm to 1.0mm.

20. An electronic device comprising: Devices, and The flexible circuit board according to any one of claims 1-19, wherein the bending region of the flexible circuit board is bent along the edge of the device, and the reinforcing layer is located on the surface of the flexible body near the device.

21. The electronic device according to claim 20, wherein, The thickness of the device is B, and the alignment tolerance between the flexible circuit board and the device is A. The first bending region and the second bending region have the same length, which is 2A. The length of the intermediate region is B-2A. A is 0.1mm to 1.0mm.

Images