Flexible circuit board and electronic device

Abstract

The utility model discloses a flexible circuit board and an electronic device, the flexible circuit board is provided with a first connecting end, a second connecting end and a bending area between the first connecting end and the second connecting end, and the bending area comprises a flexible main body and a reinforcing layer; the flexible body comprises a first bending area close to the first connecting end, a second bending area close to the second connecting end and a middle area located between the first bending area and the second bending area. The reinforcing layer is arranged on the surface of the flexible body and comprises a first reinforcing part located in the middle area and second reinforcing parts located in the first bending area and the second bending area respectively, and the rigidity of the first reinforcing part is larger than that of the second reinforcing parts. The flexible circuit board has better bending performance and stability, and the narrow frame design of the electronic device can be realized.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to a flexible circuit board and an electronic device. Background Art

[0002] Flexible printed circuit (FPC), also known as soft circuit board, flexible circuit board, is popular for its excellent properties such as light weight, thin thickness, free bending and folding. In some electronic devices, flexible circuit boards can be used as connecting circuits between electronic components and integrated circuits, so that the integrated circuits can control the working status of electronic components. Utility Model Content

[0003] At least one embodiment of the present disclosure provides a flexible circuit board, which has a first connection end, a second connection end, and a bending area between the first connection end and the second connection end, wherein the bending area includes a flexible body and a reinforcement layer; the flexible body includes a first bending area close to the first connection end, a second bending area close to the second connection end, and an intermediate area between the first bending area and the second bending area; the reinforcement layer is arranged on the surface of the flexible body, including a first reinforcement part located in the intermediate area and a second reinforcement part located in the first bending area and the second bending area respectively, wherein the stiffness of the first reinforcement part is greater than the stiffness of the second reinforcement part.

[0004] For example, in the flexible circuit board provided in at least one embodiment of the present disclosure, the first reinforcement part includes a first reinforcement sublayer, which is arranged on the surface of the flexible body and located in the middle area, and the second reinforcement part includes a second reinforcement sublayer, which is arranged on the surface of the flexible body and located in the first bending area and the second bending area.

[0005] For example, in the flexible circuit board provided in at least one embodiment of the present disclosure, the average thickness of the second strengthening sublayer is less than the average thickness of the first strengthening sublayer.

[0006] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the thickness of the second strengthening sublayer gradually decreases in a direction away from the middle area.

[0007] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the first reinforcement part also includes a third reinforcement sublayer, and the third reinforcement sublayer is arranged on a side of the first reinforcement sublayer away from the flexible body, and the first reinforcement sublayer and the second reinforcement sublayer are made of the same material and are integrally connected.

[0008] For example, in the flexible circuit board provided in at least one embodiment of the present disclosure, the thickness of the first strengthening sublayer and the second strengthening sublayer ranges from 0.01 mm to 0.15 mm, and the thickness of the third strengthening sublayer ranges from 0.01 mm to 0.25 mm.

[0009] For example, in the flexible circuit board provided in at least one embodiment of the present disclosure, the first bending region and the second bending region respectively have relative first edge regions and second edge regions in the width direction of the bending regions, and the second reinforcement sublayer is arranged in the first edge regions and the second edge regions.

[0010] For example, in the flexible circuit board provided in at least one embodiment of the present disclosure, the first strengthening sublayer and the second strengthening sublayer are disconnected at the boundary between the first bending area and the middle area and at the boundary between the second bending area and the middle area.

[0011] For example, in the flexible circuit board provided in at least one embodiment of the present disclosure, the average thickness of the second strengthening sublayer is 1 / 3 to 1 / 2 of the average thickness of the first strengthening sublayer.

[0012] For example, in the flexible circuit board provided in 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:

[0013] e=C-2d,

[0014] 0.5mm≤d≤1mm.

[0015] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the material of the first reinforcement sublayer is different from the material of the second reinforcement sublayer, and the stiffness of the material of the first reinforcement sublayer is greater than the stiffness of the material of the second reinforcement sublayer.

[0016] For example, in the flexible circuit board provided in at least one embodiment of the present disclosure, the first reinforcing sublayer is made of metal material or organic material; and the second reinforcing sublayer is made of foam or ink.

[0017] For example, in the flexible circuit board provided in 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, which is a curing glue.

[0018] For example, in the flexible circuit board provided in at least one embodiment of the present disclosure, the thickness of the second reinforcement sublayer is less than the thickness of the first reinforcement sublayer, and at the boundary between the first reinforcement sublayer and the second reinforcement sublayer, the cross-section of the first reinforcement sublayer and the second reinforcement sublayer is generally arc-shaped or stepped.

[0019] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the second reinforcement sublayer includes at least one hollow portion.

[0020] For example, in the flexible circuit board provided in at least one embodiment of the present disclosure, the second reinforcement sublayer includes a plurality of hollow portions, and the plurality of hollow portions are arranged along the length direction and the width direction of the bending area.

[0021] For example, in the flexible circuit board provided in at least one embodiment of the present disclosure, the plurality of hollow portions are in the shape of long strips and extend along the width direction.

[0022] 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 portions gradually increases or decreases in a direction away from the middle area.

[0023] For example, in the flexible circuit board provided by at least one embodiment of the present disclosure, the size of the plurality of hollow portions in the width direction of the bending area is c, the size in the length direction of the bending area is a, the spacing between two adjacent hollow portions in the width direction and the length direction is b, and the width of the bending area is C, then:

[0024] 0.5mm≤b≤1mm,

[0025] 0.05mm≤a≤(2A-3b) / 3,

[0026] 0.5mm≤c≤Cb,

[0027] Among them, A is the alignment tolerance, which is 0.1mm~1.0mm.

[0028] At least one embodiment of the present disclosure provides an electronic device, which includes a device and a flexible circuit board provided by an embodiment of the present disclosure, wherein a bending area of ​​the flexible circuit board is bent along an edge of the device, and the strengthening layer is located on a surface of the flexible body close to the device.

[0029] For example, in the electronic device provided in at least one embodiment of the present disclosure, the thickness of the device is B, the alignment tolerance between the flexible circuit board and the device 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 THE DRAWINGS

[0030] 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 below. Obviously, the drawings in the following description only relate to some embodiments of the present disclosure, but are not intended to limit the present disclosure.

[0031] Figure 1 is a cross-sectional schematic diagram of an electronic device;

[0032] Figure 2 for Figure 1 An enlarged schematic diagram of the circled portion of the electronic device;

[0033] Figure 3 A schematic plan view of a flexible circuit board;

[0034] Figure 4 for Figure 2 An enlarged schematic diagram of the circled portion of the electronic device;

[0035] Figure 5 A schematic plan view of a flexible circuit board provided in at least one embodiment of the present disclosure;

[0036] Figure 6 A schematic plan view of a bending area in a flexible circuit board provided in at least one embodiment of the present disclosure;

[0037] Figure 7 A schematic cross-sectional view of a bending area in a flexible circuit board provided in at least one embodiment of the present disclosure;

[0038] Figure 8 A schematic cross-sectional view of a bending area of ​​a flexible circuit board after bending provided by at least one embodiment of the present disclosure;

[0039] Fig. 9 Another cross-sectional schematic diagram of a bending area in a flexible circuit board provided in at least one embodiment of the present disclosure;

[0040] Fig.10 Another cross-sectional schematic diagram of a bending area in a flexible circuit board provided in at least one embodiment of the present disclosure;

[0041] Fig.11 Another cross-sectional schematic diagram of a bending area in a flexible circuit board provided in at least one embodiment of the present disclosure;

[0042] Fig.12 A schematic plan view of a bending area in another flexible circuit board provided in at least one embodiment of the present disclosure;

[0043] Fig.13 A schematic cross-sectional view of a bending area in another flexible circuit board provided in at least one embodiment of the present disclosure;

[0044] Fig.14 Another cross-sectional schematic diagram of a bending area in another flexible circuit board provided in at least one embodiment of the present disclosure;

[0045] Fig.15A schematic cross-sectional view of a bending area in yet another flexible circuit board provided in at least one embodiment of the present disclosure;

[0046] Fig.16 Another cross-sectional schematic diagram of a bending area in yet another flexible circuit board provided in at least one embodiment of the present disclosure;

[0047] Fig.17 and Fig.18 They are schematic cross-sectional views of a bending area in yet another flexible circuit board during the preparation process provided by at least one embodiment of the present disclosure;

[0048] Figure 19-22 They are respectively plan schematic diagrams of a bending area in yet another flexible circuit board provided in at least one embodiment of the present disclosure;

[0049] Fig.23 A schematic plan view of a hollow portion in a bending area of ​​yet another flexible circuit board provided in at least one embodiment of the present disclosure;

[0050] Fig.24 and Fig.25 They are schematic cross-sectional views of a bending area in yet another flexible circuit board provided in at least one embodiment of the present disclosure; and

[0051] Fig.26 A cross-sectional schematic diagram of the alignment of a device and a flexible circuit board in an electronic device provided by at least one embodiment of the present disclosure. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0053] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0054] Figure 1 is a schematic cross-sectional view of an electronic device, taking the electronic device as a display device as an example. Figure 1 As shown, 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. One side of the flexible circuit board 6 is electrically connected to the display panel 4, such as bonding, and the other side is electrically connected to the integrated circuit 7, such as through a B2B connector or a ZIF connector, so as to realize the circuit connection of the integrated circuit 7 → the flexible circuit board 6 → the display panel 4.

[0055] The connection portion between the flexible circuit board 6 and the integrated circuit 7 usually needs to be bent once or multiple times to achieve electrical connection. For example, Figure 2 Shows Figure 1 An enlarged schematic diagram of the electronic device in the circle, such as Figure 1 and 2 As shown, the flexible circuit board 6 needs to be bent 180° to electrically connect the integrated circuit 7 to the display panel 4. In order to facilitate bending and save space, the bending portion is usually slender. Figure 3 A schematic plan view of a flexible circuit board 6 is shown. Figure 3 As shown, the bending portion 61 is elongated.

[0056] In some embodiments, in order to achieve thinness and lightness of the product, Figure 2 As shown, some components 8 are often placed inside and outside the bending portion 61. Figure 3 As shown, the bending portion 61 is provided with a silk screen line 9, and the silk screen line 9 can help the naked eye judge the accuracy of the bending position.

[0057] like Figure 2 As shown, when the flexible circuit board 6 is in a bent state, the bending arc is large and occupies a space of length L. Figure 4 Shows Figure 2 An enlarged schematic diagram of the circled part in Figure 4 As shown, the bent portion 61 contacts the part 8 at the edge of the part 8, as shown in FIG. Figure 4 As shown in the circle in the figure, the surface of the flexible circuit board 6 is easily scratched by the component 8, and even the circuit is broken, which affects the normal operation of the electronic device.

[0058] At least one embodiment of the present disclosure provides a flexible circuit board and an electronic device, wherein the flexible circuit board has a first connection end, a second connection end, and a bending area between the first connection end and the second connection end, wherein the bending area includes a flexible body and a reinforcement layer; the flexible body includes a first bending area close to the first connection end, a second bending area close to the second connection end, and an intermediate area between the first bending area and the second bending area; the reinforcement layer is arranged on the surface of the flexible body, including a first reinforcement part located in the intermediate area and a second reinforcement part located in the first bending area and the second bending area, respectively, wherein the stiffness of the first reinforcement part is greater than the stiffness of the second reinforcement part.

[0059] In the above-mentioned flexible circuit board provided in at least one embodiment of the present disclosure, a reinforcement layer is provided in the bending area to prevent scratches by components after bending, thereby achieving the effect of protecting the structure of the bending area; in addition, the stiffness of the first reinforcement part of the reinforcement layer in the middle area is greater than the stiffness of the second reinforcement part in the first bending area and the second bending area located on both sides of the middle area, thereby reducing the bending curvature of the bending area in the middle area, thereby reducing the space occupied by the bending area after bending, so as to facilitate the realization of a narrow frame design.

[0060] The flexible circuit board and the electronic device provided by the embodiments of the present disclosure are described below through several specific embodiments.

[0061] At least one embodiment of the present disclosure provides a flexible circuit board. Figure 5 shows a plan view of the flexible circuit board, Figure 6 A schematic plan view of the bending area of ​​a flexible circuit board is shown. Figure 7 A schematic cross-sectional view of a bending area of ​​a flexible circuit board is shown. Figure 8 FIG. 4 shows a schematic cross-sectional view of the bending area of ​​the flexible circuit board after bending. Figure 5 As shown, the flexible printed circuit board has a first connection end 11 , a second connection end 12 and a bending area 13 between the first connection end 11 and the second connection end 12 .

[0062] For example, the first connection end 11 has a connection device such as a B2B connector or a ZIF connector to facilitate the electrical connection of the flexible circuit board with an integrated circuit or other control device, and the second connection end 12 has a binding circuit to facilitate the electrical connection of the flexible circuit board with an electronic device, such as a display panel. The bending area 13 can be bent, for example, 180°, to overlap the two devices connected to the flexible circuit board to achieve a narrow frame design. For example, in other embodiments, the connection methods of the first connection end 11 and the second connection end 12 can also be interchangeable, and the embodiments of the present disclosure are not specifically limited to this.

[0063] like Figure 6 and Figure 7 As shown, the bending area 13 includes a flexible body 21 and a reinforcing layer 22; Figure 5-Figure 7 The flexible body 21 includes a first bending area 131 close to the first connection end 11, a second bending area 132 close to the second connection end 12, and an intermediate area 133 located between the first bending area 131 and the second bending area 132; the reinforcement layer 22 is arranged on the surface of the flexible body 21, including a first reinforcement part 221 located in the intermediate area 133 and a second reinforcement part 222 located in the first bending area 131 and the second bending area 132 respectively, and the stiffness of the first reinforcement part 221 is greater than the stiffness of the second reinforcement part 222.

[0064] Therefore, the bending region 13 is provided with a strengthening layer 22, and after the bending region 13 is bent, Figure 8 As shown, the bending area 13 can be prevented from being scratched by the component 8, thereby achieving the effect of protecting the structure of the bending area 13; in addition, the stiffness of the first reinforcement part 221 of the reinforcement layer 22 in the middle area 133 is greater than the stiffness of the second reinforcement part 222 in the first bending area 131 and the second bending area 132 located on both sides of the middle area 133, thereby reducing the bending curvature of the bending area 13 (for example, the middle area 133), thereby reducing the space L occupied by the bending area 13 after bending, so as to facilitate the realization of a narrow frame design.

[0065] For example, in some embodiments, the flexible body 21 includes a flexible substrate, a circuit pattern disposed on the flexible substrate, and a packaging layer covering the circuit pattern. For details, reference may be made to the relevant art. In this case, the strengthening layer 22 may be attached to the inner surface of the flexible body 21 (i.e., the inner surface after bending, such as Figure 8 The additional structure on the left surface of the flexible circuit board (as shown in the figure) is, 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.

[0066] For example, the bending area 13 is in the shape of a long strip, such as Figure 6As shown in FIG. 1 , the length direction of the bending region 13 is along the horizontal direction in the figure, and the width direction is along the vertical direction in the figure. For example, when the bending region 13 is bent, the bending axis is along the width direction, thereby forming a Figure 8 Bend shown.

[0067] For example, in some embodiments, the structures of the first reinforcement part 221 and the second reinforcement part 222 are different, such as different setting ranges, different thicknesses, different materials, different patterns, etc., so that the stiffness of the first reinforcement part 221 is greater than the stiffness of the second reinforcement part 222.

[0068] For example, in some embodiments, the thickness of the first reinforcement portion 221 can be 0.02mm~0.40mm, for example, 0.02mm, 0.05mm, 0.10mm, 0.15mm, 0.20mm, 0.25mm, 0.30mm, 0.35mm or 0.40mm, and the thickness of the second reinforcement portion 222 can be 0.01mm~0.15mm, for example, 0.02mm, 0.04mm, 0.06mm, 0.08mm, 0.10mm, 0.12mm, 0.13mm or 0.15mm, etc.

[0069] For example, in some embodiments, Figure 7 As shown, the first reinforcement part 221 includes a first reinforcement sublayer 31, which is arranged on the surface of the flexible body 21 and located in the middle area 133. The second reinforcement part 222 includes a second reinforcement sublayer 32, which is also arranged on the surface of the flexible body 21 and located in the first bending area 131 and the second bending area 132.

[0070] For example, in some embodiments, the average thickness of the second strengthening sub-layer 32 is less than the average thickness of the first strengthening sub-layer 31 .

[0071] In the embodiment of the present disclosure, the thickness of a structure refers to the dimension of the structure in a direction perpendicular to the surface of the flexible body 21. Figure 7 The average thickness of a structure refers to the average thickness of the structure at various locations in its setting area.

[0072] For example, in some embodiments, Fig. 9 As shown, the first strengthening sublayer 31 has a uniform thickness in the middle region 133 (i.e., an equal thickness design is adopted), which is a first thickness, and the second strengthening sublayer 32 has a uniform thickness in the first bending region 131 and the second bending region 132, which is a second thickness, and the first thickness is greater than the second thickness; or, in other embodiments, in the direction away from the middle region 133, the thickness of the second strengthening sublayer 32 gradually decreases, for example, as Figure 7As shown, the thickness of the second strengthening sublayer 32 gradually decreases, and the cross section presents an arc shape to achieve a smooth transition; or Fig.10 As shown, in the direction away from the middle region 133 , the thickness of the second strengthening sub-layer 32 decreases in a step-like manner, and the cross section presents a step-like shape.

[0073] Therefore, the rigidity of the first strengthening sublayer 31 is greater than the rigidity of the second strengthening sublayer 32. After the bending area 13 is bent, the second strengthening sublayer 32 can prevent the bending area 13 from being scratched by the component 8 in the first bending area 131 and the second bending area 132, thereby protecting the structure of the bending area 13; the first strengthening sublayer 31 has a greater rigidity in the middle area 133, thereby reducing the bending curvature of the bending area 13 (for example, the middle area 133), thereby reducing the space L occupied by the bending area 13 after bending, so as to realize a narrow frame design.

[0074] For example, in other embodiments, Fig.11 As shown, the first reinforcement part 221 may also include more reinforcement sublayers, such as a third reinforcement sublayer 33, which is disposed on a side of the first reinforcement sublayer 31 away from the flexible body 21. In this case, the first reinforcement sublayer 31 and the second reinforcement sublayer 32 may be made of the same material and connected as one. Thus, the first reinforcement part 221 has more reinforcement sublayers to have greater rigidity.

[0075] For example, in Fig.11 In the embodiment, the thickness of the first strengthening sublayer 31 and the second strengthening sublayer 33 (that is, the dimension in the vertical direction in the figure) ranges from 0.01 mm to 0.15 mm, for example, 0.01 mm, 0.03 mm, 0.05 mm, 0.08 mm, 0.10 mm, 0.12 mm or 0.15 mm, etc.; the thickness of the third strengthening sublayer 33 ranges from 0.01 mm to 0.25 mm, for example, 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.

[0076] For example, for small and medium-sized products such as wearable watches or mobile phones, and for medium-sized products such as tablets and laptops, the thickness range of the first strengthening sublayer 31 and the second strengthening sublayer 33 can be 0.01mm-0.10mm, and the thickness range of the third strengthening sublayer 33 is 0.01mm-0.20mm, such as 0.01mm, 0.03mm, 0.05mm, 0.08mm, 0.10mm, 0.12mm, 0.15mm, 0.18mm or 0.20mm; for example, for medium and large-sized products such as televisions and monitors, For size products, the thickness range of the first strengthening sublayer 31 and the second strengthening sublayer 33 is 0.03mm~0.15mm, for example, 0.03mm, 0.05mm, 0.08mm, 0.10mm, 0.12mm or 0.15mm; the thickness range of the third strengthening sublayer 33 is 0.03mm~0.25mm, for example, 0.03mm, 0.05mm, 0.08mm, 0.10mm, 0.12mm, 0.15mm, 0.18mm, 0.20mm, 0.22mm or 0.25mm.

[0077] For example, in some embodiments, the first strengthening sublayer 31, the second strengthening sublayer 32 and the third strengthening sublayer 33 are an integrated structure. For example, during the preparation process, the first strengthening sublayer 31, the second strengthening sublayer 32 and the third strengthening sublayer 33 are formed integrally, and then the portions of the integrally formed strengthening material located in the first bending area 131 and the second bending area 132 are grooved to obtain the integrated first strengthening sublayer 31, the second strengthening sublayer 32 and the third strengthening sublayer 33. At this time, in the middle area 133, the sum of the thickness of the first strengthening sublayer 31 and the third strengthening sublayer 33 can be 0.02mm~0.40mm, for example, 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 strengthening sublayer 32 can be 0.01mm~0.15mm, for example, 0.02mm, 0.04mm, 0.06mm, 0.08mm, 0.10mm, 0.12mm, 0.13mm or 0.15mm, etc.

[0078] Alternatively, in other embodiments, the second reinforcement portion 222 may also include multiple reinforcement sublayers, but the number of the multiple reinforcement sublayers included in the second reinforcement portion is less than the number of the multiple reinforcement sublayers included in the first reinforcement portion 221, so that the stiffness of the first reinforcement portion 221 is greater than the stiffness of the second reinforcement portion 222.

[0079] For example, in Figure 7 and Figure 9-10In the embodiment of the present invention, the materials of the first reinforcement sublayer 31 and the second reinforcement sublayer 32 may be the same or different, as long as the stiffness of the first reinforcement portion 221 is greater than the stiffness of the second reinforcement portion 222. For example, in other embodiments, the first reinforcement portion 221 and the second reinforcement portion may have the same thickness but have different materials, so that the stiffness of the first reinforcement portion 221 is greater than the stiffness of the second reinforcement portion 222.

[0080] For example, in some embodiments, the first strengthening sublayer 31 and the second strengthening sublayer 32 can be made of organic insulating materials, such as polyethylene terephthalate (PET), etc. The material has a certain rigidity, and can block the sharp corners of the component 8 from the surface of the flexible circuit board in the first bending area 131 and the second bending area 132 to avoid direct contact between the two, so as to protect the flexible circuit board from damage; the middle area 133 plays a supporting role, so that the middle area 133 is approximately straight after bending, reducing the bending curvature, thereby saving assembly space, such as Figure 8 shown.

[0081] For example, in Fig.11 In the embodiment of the present invention, the material of the third strengthening sublayer 33 can be the same as the material of the first strengthening sublayer 31 and the second strengthening sublayer 32, thereby increasing the thickness of the first strengthening portion 221 in the middle region 133, thereby improving its rigidity. Alternatively, in other embodiments, the material of the third strengthening sublayer 33 can also be other organic materials or metal materials to improve the rigidity of the first strengthening portion 221.

[0082] For example, Fig.12 FIG. 1 shows a plan view of a bending region of another flexible substrate provided by at least one embodiment of the present disclosure. In other embodiments, Fig.12 As shown, the first bending region 131 and the second bending region 132 respectively have a first edge region 134 and a second edge region 135 opposite to each other in the width direction (vertical direction in the figure) of the bending region 13, and the second strengthening sublayer 32 is arranged in the first edge region 134 and the second edge region 135, but not in the region between the first edge region 134 and the second edge region 135. At this time, the second strengthening sublayer 32 is hollowed out in the middle part of the first bending region 131 and the second bending region 132, thereby reducing the rigidity of the second strengthening sublayer 32.

[0083] For example, the first strengthening sublayer 31 and the second strengthening sublayer 32 are disconnected at the boundary between the first bending region 131 and the middle region 133 and at the boundary between the second bending region 132 and the middle region 133, that is, the first strengthening sublayer 31 and the second strengthening sublayer 32 are not connected together. For example, during the preparation process, a cut-off line can be made at the boundary between the first bending region 131 and the middle region 133 and at the boundary between the second bending region 132 and the middle region 133 to improve the bending effect.

[0084] For example, in some embodiments, the average thickness of the second strengthening sublayer 32 is 1 / 3 to 1 / 2 of the average thickness of the first strengthening sublayer 31, such as 1 / 3, 3 / 8, 5 / 12, 13 / 24 or 1 / 2. Fig.13 As shown, the second strengthening sublayer 32 may have a uniform thickness (i.e., an equal thickness design) in the first edge region 134 and the second edge region 135, which is the third thickness, and a uniform thickness in the middle region 133, which is the first thickness. The third thickness is less than the first thickness, for example, the third thickness is 1 / 3 to 1 / 2 of the first thickness, for example, 1 / 3, 3 / 8, 5 / 12, 13 / 24 or 1 / 2, etc.; or, as Fig.14 As shown, in the direction away from the middle region 133, the thickness of the second strengthening sublayer 32 gradually decreases, for example, the cross section of the second strengthening sublayer 32 is in an arc shape, thereby achieving a smooth transition; or, referring to Fig.10 In the direction away from the middle region 133 , the thickness of the second strengthening sublayer 32 decreases in a step-like manner, and the cross section is in a step-like shape.

[0085] For example, in some embodiments, Fig.12 As shown, the width of the bending area 13 is C, the size of the first edge area 134 and the second edge area 435 in the width direction of the bending area 13 is d, and the shortest distance between the first edge area 134 and the second edge area 135 is e. Considering the cutting and bonding process, d ≥ 0.5 mm. At the same time, in order to reduce the rigidity of the first bending area 131 and the second bending area 132 as much as possible, it is recommended that d is less than or equal to 1 mm, then:

[0086] e=C-2d,

[0087] 0.5mm≤d≤1mm.

[0088] The above design fully considers the feasibility of the manufacturing process and the rigidity design of the second strengthening sublayer 32 and the first strengthening sublayer 31 , while improving the manufacturing yield and product reliability of the light-emitting unit.

[0089] For example, in Figure 12-14 In the embodiment, the materials of the first strengthening sub-layer 31 and the second strengthening sub-layer 32 may be the same or different.

[0090] For example, corresponding to Figure 6 or Fig.12 In the case of arrangement, the material of the first strengthening sublayer 31 and the material of the second strengthening sublayer 32 can be different, so that the rigidity of the material of the first strengthening sublayer 31 can be greater than the rigidity of the material of the second strengthening sublayer 32 by selecting the material. For example, the first strengthening sublayer 31 can be made of a hard material, such as a metal material, an alloy material or an organic material, such as stainless steel or PET, and the second strengthening sublayer 32 can be made of a soft material, such as foam or ink, for example, the ink can be a photosensitive solder mask ink. Thus, the first strengthening sublayer 31 can have a larger rigidity, thereby achieving a smaller bending curvature, thereby reducing the occupied space L, and at the same time, the second strengthening sublayer 32 can have a smaller rigidity, achieving a protective effect, and preventing the flexible circuit board from being scratched.

[0091] For example, when the material of the first strengthening sublayer 31 is different from the material of the second strengthening sublayer 32, as shown in FIG. Fig.15 As shown, the thickness of the first strengthening sublayer 31 may be equal to the thickness of the second strengthening sublayer 32; or Fig.16 As shown, the average thickness of the first strengthening sublayer 31 can be greater than the average thickness of the second strengthening sublayer 32; in this case, the first strengthening sublayer 31 and the second strengthening sublayer 32 can be designed with uniform thickness (refer to Fig.13 , equal thickness design), or, in the direction away from the middle area 133, the thickness of the second strengthening sublayer 32 gradually decreases, for example, the cross section of the second strengthening sublayer 32 is in an arc shape to achieve a smooth transition; or, refer to Fig.10 In the direction away from the middle region 133 , the thickness of the second strengthening sublayer 32 decreases in a step-like manner, and the cross section is in a step-like shape.

[0092] For example, in other embodiments, corresponding to Figure 6 or Fig.12 In the case of arrangement, the material of the first strengthening sublayer 31 and the material of the second strengthening sublayer 32 can be the same, for example, an organic insulating material such as a curing glue, such as a heat-curing glue or a light-curing glue (such as a UV curing glue), etc. The curing glue is a viscous soft material before curing, and is cured after heating or light exposure to improve the rigidity.

[0093] For example, the thickness of the second strengthening sublayer 32 can be less than the thickness of the first strengthening sublayer 31, and at the boundary between the first strengthening sublayer 31 and the second strengthening sublayer 32, the cross-section of the first strengthening sublayer 31 and the second strengthening sublayer 32 is generally arc-shaped or stepped, or oblique. For example, the curvature of the arc can be toward the flexible circuit board (the form shown in the figure), or it can also be away from the flexible circuit board, and the embodiments of the present disclosure do not specifically limit this. Therefore, in the first bending area 131 and the second bending area 132, the thickness of the curing glue is relatively thin, and it can still maintain a relatively low rigidity after curing, so it can play a role in preventing the flexible circuit board from being scratched, while the thickness of the curing glue in the middle area 133 is relatively large, and has a relatively large rigidity, which can achieve the effect of reducing the curvature of the bending and reducing the occupied space.

[0094] For example, during the preparation process, curing glue of different thicknesses can be produced by controlling the number of glue coating layers, glue dispensing pressure, glue dispensing speed and other parameters. For example, based on the above parameters, the coating method of the starting and ending positions of the glue coating in the middle area 133 can be controlled to make the transition area present different shapes.

[0095] For example, Fig.17 As shown, the first reinforcing sublayer 31 can be formed by coating multiple layers of curing glue in the middle region 133, and a single layer or multiple layers of curing glue with fewer layers than the middle region 133 can be coated in the first bending region 131 and the second bending region 132 to form the second reinforcing sublayer 32. When coating multiple layers of curing glue in the middle region 133, if the starting and ending positions of each layer of glue are the same or close to each other, an arc shape is eventually formed at the junction of the first reinforcing sublayer 31 and the second reinforcing sublayer 32 due to the natural flow of the curing glue. Thus, through the above process, the thickness of the first reinforcing sublayer 31 is greater than the thickness of the second reinforcing sublayer 32, and when the curing glue is cured, a smooth transition is formed at the junction of the first reinforcing sublayer 31 and the second reinforcing sublayer 32, thereby forming an arc-shaped cross-section, as shown in FIG. Fig.17 Shown in the middle circle.

[0096] Or, if Fig.18 As shown in FIG. 1 , the starting and ending positions of the multi-layer curing glue applied in the middle area 133 do not overlap, but in each adjacent two layers, the upper layer is retracted relative to the lower layer, that is, there is a certain interval between the starting and ending positions of the glue application, so that after curing, a step-like transition is formed at the junction of the first reinforcing sublayer 31 and the second reinforcing sublayer 32, thereby forming a step-like cross-section, as shown in FIG. Fig.18 Shown in the middle circle.

[0097] For example, Fig.19 FIG. 1 shows a plan view of another flexible circuit board provided by at least one embodiment of the present disclosure, such as Fig.19As shown, the second strengthening sublayer 32 includes at least one hollow portion H, for example, multiple hollow portions H. For example, multiple hollow portions H are arranged along the length direction (horizontal direction in the figure) and the width direction (vertical direction in the figure) of the bending area 13, for example, they can be arranged in multiple rows and columns, one row and multiple columns, or multiple rows and one column. The provision of the hollow portion H can reduce the rigidity of the second strengthening sublayer 32, so that it has better bending performance, and at the same time prevent the flexible circuit board from being scratched. For example, the hollow portion H can make the first bending area 131 and the second bending area 132 play a hinge-like role, which is conducive to smooth bending at the corners of the component 8.

[0098] For example, in some embodiments, the plurality of hollow portions H are in a long strip shape, such as an ellipse, a racetrack shape, or an H shape, and extend along the width direction of the bending area 13, thereby conforming to the bending of the bending area 13 and achieving a better bending effect. For example, in other embodiments, the plurality of hollow portions H may also be in a circular, square, or other suitable shape, which is not specifically limited in the embodiments of the present disclosure.

[0099] For example, in some embodiments, the plurality of hollow portions H may be arranged evenly, aligned, or staggered. Fig.19 As shown, the plurality of hollow portions H are aligned and arranged uniformly along the row direction and the column direction; or, as shown Fig. 20 As shown, the plurality of hollow portions H are aligned along the row direction and staggered along the column direction, and the plurality of hollow portions H are uniformly arranged overall; or, as shown Fig.21 As shown, in some embodiments, in the direction away from the middle area 133, the arrangement density of the plurality of hollow portions H gradually decreases; or, as shown in FIG. Fig. 22 As shown in FIG. 1 , in the direction away from the middle area 133, the arrangement density of the plurality of hollow portions H gradually increases. Fig.21 and Fig. 22 In the embodiment, the arrangement of the plurality of hollow portions H in the first bending region 131 and the second bending region 132 is symmetrical, so that the first bending region 131 and the second bending region 132 have substantially the same bending effect on both sides of the middle region 133 .

[0100] For example, in some embodiments, Fig.23As shown, the distance between two adjacent hollow parts H in the width direction and the length direction of the bending area 13 is b. Considering the cutting process and the bending effect, the hollow distance b ranges from 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 hollow parts 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, 0.9mm or 1.0mm, etc. 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 achieve the hinge effect, the hollow part H must have at least 3 columns, and the maximum value of a must satisfy (a+b)*3=2A; the size of the plurality of hollow parts H in the width direction of the bending area 13 is c, and 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 part H has at least 1 row, such as Fig.19 As shown, the width of the bending area 13 is C, and the maximum value of c must satisfy c+b=C, that is, c≤Cb; then:

[0101] 0.5mm≤b≤1mm,

[0102] 0.05mm≤a≤(2A-3b) / 3,

[0103] 0.5mm≤c≤Cb,

[0104] Wherein, A is the alignment tolerance, for example, the alignment tolerance between the bending area 13 and the component 8, which is 0.1 mm to 1.0 mm, for example, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm or 1.0 mm, etc. Through the above-mentioned size design, the feasibility of the preparation process and the stability and bending shape of the prepared product can be taken into account at the same time, thereby improving the bending effect and preparation yield of the flexible circuit board.

[0105] For example, in the above embodiment, the thickness of the first strengthening sublayer 31 and the second strengthening sublayer 32 may be the same, and part of the material of the second strengthening sublayer 32 is removed to form a plurality of hollow portions H. For example, in some examples, the hollow portion H may penetrate the second strengthening sublayer 32, or, in some examples, the hollow portion H may not penetrate the second strengthening sublayer 32, such as Fig.24 shown.

[0106] For example, in the above embodiment, the thickness of the first strengthening sublayer 31 and the second strengthening sublayer 32 may also be different. Fig.25As shown, the hollow portion H may penetrate the second strengthening sublayer 32 , or, in other examples, the hollow portion H may not penetrate the second strengthening sublayer 32 , and the embodiments of the present disclosure do not specifically limit this.

[0107] For example, in the above embodiment, the sizes and shapes of the plurality of hollow portions H are the same, so that the performance of the second strengthening sublayer 32 at various positions of the first bending region 131 and the second bending region 132 is basically the same, so as to ensure uniform force during bending and improve the reliability of the bending region 13. In other embodiments, the sizes and shapes of the plurality of hollow portions H may also be designed to be different, as long as substantially the same technical effects can be achieved.

[0108] At least one embodiment of the present disclosure further provides an electronic device, such as Figure 8 and Fig.26 As shown, the electronic device includes a device 8 and a flexible circuit board provided in an embodiment of the present disclosure. The bending area 13 of the flexible circuit board is bent along the edge of the device 8. After bending, the strengthening layer 22 is located on the surface of the flexible body 21 close to the device 8, thereby protecting the bending area 13 from being damaged by the device 8.

[0109] For example, in order to better play the supporting role of the middle area 133 and make the flexible circuit board as close to a straight line as possible in the middle area 133, the middle area 133 needs to be as long as possible without contacting the corners of the device 8. Fig.26 As shown, considering various assembly tolerances, assuming that the alignment tolerance between 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 in the first bending area 131 and the second bending area 132, avoid deviation from the first bending area 131 and the second bending area 132 due to alignment errors, and at the same time avoid the first bending area 131 and the second bending area 132 being too long, the length of the first bending area 131 and the second bending area 132 (that is, the dimension along the length direction of the bending area 13) are the same, which is 2A, and the length of the middle area 133 is B-2A, and A is usually 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.

[0110] For example, for small and medium-sized products such as wearable watches or mobile phones, A can be 0.5mm, and the length of the first bending area 131 and the second bending area 132 is approximately 1.0mm, and the length of the middle support area is approximately B-2.0mm; for example, for medium-sized products such as tablets and laptops, A can be approximately 0.7mm, and the length of the first bending area 131 and the second bending area 132 is approximately 1.4mm, and the length of the middle support area is approximately B-1.4mm; for example, for medium and large-sized products such as televisions and monitors, A can be approximately 1.0mm, and the length of the first bending area 131 and the second bending area 132 is approximately 2.0mm, and the length of the middle support area is approximately B-2.0mm.

[0111] Therefore, 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 reinforcement sublayer 32 can achieve isolation and protection. The middle area 133 corresponds to the side of the device 8 to achieve a straight or nearly straight line shape to reduce the space occupied by the bend, which is conducive to narrow frame design.

[0112] For example, the electronic device provided in the embodiment of the present disclosure may be a display device, such as an OLED display device or an LCD display device, etc. In this case, the device 8 may be an OLED display panel or an LCD display panel, and the display device may be: a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, a navigator, or any other product or component with a display function.

[0113] There are a few points to note:

[0114] (1) The drawings of the embodiments of the present disclosure only relate to the structures related to the embodiments of the present disclosure, and other structures may refer to the general design.

[0115] (2) For the sake of clarity, in the drawings used to describe the embodiments of the present disclosure, the thickness of layers or regions is exaggerated or reduced, that is, these drawings are not drawn according to the actual scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element or there may be intermediate elements.

[0116] (3) In the absence of conflict, the embodiments of the present disclosure and the features therein may be combined with each other to obtain new embodiments.

[0117] The above are only specific implementations of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and the protection scope of the present disclosure shall be based on the protection scope of the claims.

Claims

1. A flexible circuit board, characterized in that: A first connection end, a second connection end, and a bending area between the first connection end and the second connection end, wherein the bending area includes: a flexible body, comprising a first bending region near the first connection end, a second bending region near the second connection end, and an intermediate region between the first bending region and the second bending region, and A strengthening layer is arranged on the surface of the flexible body, including a first strengthening portion located in the middle area and second strengthening portions located in the first bending area and the second bending area, respectively. Wherein, the stiffness of the first reinforcement part is greater than the stiffness of the second reinforcement part.

2. The flexible circuit board according to claim 1, characterized in that: The first reinforcement portion includes a first reinforcement sublayer, and the first reinforcement sublayer is arranged on the surface of the flexible body and located in the middle area. The second reinforcement portion includes a second reinforcement sublayer, and the second reinforcement sublayer is arranged on the surface of the flexible body and located in the first bending area and the second bending area.

3. The flexible circuit board according to claim 2, characterized in that: An average thickness of the second strengthening sub-layer is smaller than an average thickness of the first strengthening sub-layer.

4. The flexible circuit board according to claim 3, characterized in that: In a direction away from the middle region, the thickness of the second strengthening sublayer gradually decreases.

5. The flexible circuit board according to claim 2, characterized in that: The first reinforcement portion further includes a third reinforcement sublayer, and the third reinforcement sublayer is arranged on a side of the first reinforcement sublayer away from the flexible body. The first strengthening sublayer and the second strengthening sublayer are made of the same material and are integrally connected.

6. The flexible circuit board according to claim 5, characterized in that: The thickness of the first strengthening sublayer and the second strengthening sublayer ranges from 0.01 mm to 0.15 mm. The thickness of the third strengthening sublayer ranges from 0.01 mm to 0.25 mm.

7. The flexible circuit board according to claim 2, characterized in that: The first bending region and the second bending region respectively have a first edge region and a second edge region opposite to each other in a width direction of the bending region, and the second strengthening sublayer is disposed in the first edge region and the second edge region.

8. The flexible circuit board according to claim 7, characterized in that: The first strengthening sublayer and the second strengthening sublayer are disconnected at a boundary between the first bending region and the middle region and at a boundary between the second bending region and the middle region.

9. The flexible circuit board according to claim 7, characterized in that: The average thickness of the second strengthening sub-layer is 1 / 3 to 1 / 2 of the average thickness of the first strengthening sub-layer.

10. The flexible circuit board according to claim 7, characterized in that: 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.

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

12. The flexible circuit board according to claim 11, characterized in that: The first strengthening sublayer is made of metal material or organic material; The second strengthening sublayer is made of foam or ink.

13. The flexible circuit board according to claim 2, characterized in that: The material of the first strengthening sub-layer is the same as that of the second strengthening sub-layer, which is curing glue.

14. The flexible circuit board according to claim 13, characterized in that: The thickness of the second strengthening sublayer is smaller than that of the first strengthening sublayer, and at the boundary between the first strengthening sublayer and the second strengthening sublayer, the cross-sections of the first strengthening sublayer and the second strengthening sublayer are generally arc-shaped or step-shaped.

15. The flexible circuit board according to claim 2, characterized in that: The second reinforcement sublayer includes at least one hollow portion.

16. The flexible circuit board according to claim 2, characterized in that: The second reinforcement sublayer includes a plurality of hollow portions, and the plurality of hollow portions are arranged along the length direction and the width direction of the bending area.

17. The flexible circuit board according to claim 16, characterized in that: The plurality of hollow portions are in a strip shape and extend along the width direction.

18. The flexible circuit board according to claim 16, characterized in that: In a direction away from the middle area, the arrangement density of the plurality of hollow portions gradually increases or decreases.

19. The flexible circuit board according to claim 16, characterized in that: The size of the plurality of hollow portions in the width direction of the bending region is c, the size in the length direction of the bending region is a, the spacing between two adjacent hollow portions in the width direction and the length direction is b, and the width of the bending region is C, then: 0.5mm≤b≤1mm, 0.05mm≤a≤(2A-3b) / 3, 0.5mm≤c≤Cb, Among them, A is the alignment tolerance, which is 0.1mm~1.0mm.

20. An electronic device, characterized in that: include: Devices, and The flexible circuit board according to any one of claims 1 to 19, wherein the bending area of ​​the flexible circuit board is bent along the edge of the device, and the strengthening layer is located on the surface of the flexible body close to the device.

21. The electronic device according to claim 20, characterized in that: The thickness of the device is B, the alignment tolerance between the flexible circuit board and the device is A, The lengths of the first bending region and the second bending region are the same, which is 2A. The length of the middle area is B-2A, A is 0.1mm~1.0mm.

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