Flexible circuit board and display device

Abstract

The present disclosure provides a flexible circuit board and a display device. The flexible circuit board includes: a main body area; a binding area, the binding area is combined with a first side of the main body area, and the binding area includes a plurality of binding pins; and an extension area, the extension area is combined with a second side of the main body area, and the first side and the second side are two opposite sides of the main body area. The main body area includes a first sub-main body area and a second sub-main body area, the second sub-main body area is located on a side of the first sub-main body area close to the extension area, the multiple traces include at least a first trace, a second trace and a third trace, the first trace, the second trace and the third trace all extend in the first sub-main body area, and the first trace and the second trace extend in the second sub-main body area. The first sub-main body area has a multi-layer board structure, the second sub-main body area has a single-layer board or a double-layer board structure, and the thickness of the second sub-main body area is less than the thickness of the first sub-main body area.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a flexible circuit board and a display device. Background Art

[0002] Flexible Printed Circuit (FPC) is a highly reliable and flexible printed circuit board made of flexible film as the substrate. Flexible circuit boards have the characteristics of high wiring density, light weight, thin thickness, good bendability, etc., and are widely used in various display devices such as mobile phones, computers and monitors. Summary of the invention

[0003] In one aspect, a flexible circuit board is provided, the flexible circuit board comprising:

[0004] A main body area, the main body area including at least one driving device and a plurality of routing lines;

[0005] a binding region coupled to the first side of the main body region, the binding region comprising a plurality of binding pins; and

[0006] an extended area, the extended area being combined with a second side of the main body area, the first side and the second side being two opposite sides of the main body area,

[0007] The main body area includes a first sub-main body area and a second sub-main body area, and the second sub-main body area is located on a side of the first sub-main body area close to the extension area; the plurality of routing lines at least include a first routing line, a second routing line and a third routing line, and the first routing line, the second routing line and the third routing line all extend in the first sub-main body area, and the first routing line and the second routing line extend in the second sub-main body area; and

[0008] The first sub-body region has a multi-layer board structure, the second sub-body region has a single-layer board or a double-layer board structure, and the thickness of the second sub-body region is smaller than that of the first sub-body region.

[0009] According to some exemplary embodiments, the first sub-body area has a first dimension along a first direction, the first direction is perpendicular to the thickness direction of the flexible circuit board and points from the binding area to the extension area; and the second sub-body area has a second dimension along the first direction, and the ratio of the sum of the first dimension and the second dimension to the first dimension of the first sub-body area is between 1.5 and 5.

[0010] According to some exemplary embodiments, the first dimension is in the range of 5 to 10 mm; and / or the sum of the first dimension and the second dimension is in the range of 7 to 20 mm.

[0011] According to some exemplary embodiments, the first sub-body region has a four-layer board structure.

[0012] According to some exemplary embodiments, the first sub-body area includes a first sub-circuit board, a second sub-circuit board and a protective film, and each of the first sub-circuit board and the second sub-circuit board includes a substrate film and conductive films disposed on opposite sides of the substrate film.

[0013] According to some exemplary embodiments, the first sub-body region has a six-layer board structure.

[0014] According to some exemplary embodiments, the first sub-main area includes a first sub-circuit board, a second sub-circuit board, a third sub-circuit board and a protective film, and each of the first sub-circuit board, the second sub-circuit board and the third sub-circuit board includes a substrate film and a conductive film arranged on opposite sides of the substrate film.

[0015] According to some exemplary embodiments, the first sub-main area includes a first sub-circuit board, a second sub-circuit board, a third sub-circuit board, a fourth sub-circuit board and a protective film, each of the first sub-circuit board and the fourth sub-circuit board includes a substrate film and a conductive film arranged on one side of the substrate film, each of the second sub-circuit board and the third sub-circuit board includes a substrate film and a conductive film arranged on opposite sides of the substrate film, and an adhesive layer is arranged between the first sub-circuit board and the second sub-circuit board, between the second sub-circuit board and the third sub-circuit board, and between the third sub-circuit board and the fourth sub-circuit board.

[0016] According to some exemplary embodiments, the second sub-body region has a double-layer board structure, the double-layer board structure includes a double-layer sub-circuit board, and the double-layer sub-circuit board includes a substrate film and conductive films disposed on opposite sides of the substrate film.

[0017] According to some exemplary embodiments, one of the first sub-circuit board, the second sub-circuit board, and the third sub-circuit board extends continuously with the double-layer sub-circuit board.

[0018] According to some exemplary embodiments, the second sub-body region has a double-layer board structure, the double-layer board structure includes a double-layer sub-circuit board, and the double-layer sub-circuit board includes a substrate film and conductive films disposed on opposite sides of the substrate film.

[0019] According to some exemplary embodiments, one of the second sub-circuit board and the third sub-circuit board extends continuously with the double-layer sub-circuit board.

[0020] According to some exemplary embodiments, the second sub-body region has a single-layer board structure, the single-layer board structure includes a single-layer sub-circuit board, and the single-layer sub-circuit board includes a substrate film and a conductive film disposed on one side of the substrate film.

[0021] According to some exemplary embodiments, one of the first sub-circuit board and the fourth sub-circuit board extends continuously with the single-layer sub-circuit board.

[0022] According to some exemplary embodiments, the first sub-body area has a third dimension along a second direction, the second sub-body area has a fourth dimension along the second direction, the second direction is perpendicular to the thickness direction of the flexible circuit board and perpendicular to the first direction; and the third dimension is equal to the fourth dimension, or the third dimension is greater than the fourth dimension.

[0023] According to some exemplary embodiments, the protruding area has a double-layer plate structure or a single-layer plate structure.

[0024] According to some exemplary embodiments, the extension region and the second sub-body region extend continuously.

[0025] According to some exemplary embodiments, as the first size of the first sub-body region increases, the projected area of ​​the second sub-body region along the thickness direction of the flexible circuit board decreases.

[0026] According to some exemplary embodiments, the binding area has a double-layer board structure or a single-layer board structure.

[0027] According to some exemplary embodiments, the binding area and the second sub-body area are led out from a same sub-circuit board of the first sub-body area.

[0028] According to some exemplary embodiments, the binding region and the second sub-body region are led out from different sub-circuit boards of the first sub-body region.

[0029] On the other hand, a display device is provided, comprising: a display panel; a flexible circuit board as described above; and a battery, wherein a binding area of ​​the flexible circuit board is connected to the display panel, and the flexible circuit board is located on a non-display side of the display panel; and the battery is located on a side of the flexible circuit board facing away from the display panel.

[0030] According to some exemplary embodiments, an orthographic projection of the battery on the display panel at least partially overlaps with an orthographic projection of the second sub-body area on the display panel.

[0031] According to some exemplary embodiments, the display device further includes a middle frame component, at least a portion of the middle frame component is located on a side of the flexible circuit board facing away from the display panel, and an orthographic projection of the middle frame component on the display panel at least partially overlaps with an orthographic projection of the second sub-body area on the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 A schematic diagram of a display device according to an embodiment of the present disclosure is shown;

[0034] Figure 2 A partially exploded schematic diagram of a display device provided by an embodiment of the present disclosure;

[0035] Figure 3A and Figure 3B The display device of the embodiment of the present disclosure is respectively Figure 2 A schematic cross-sectional view taken along the I-I' line;

[0036] Figure 4 is a schematic plan view of a flexible circuit board according to some exemplary embodiments of the present disclosure, which shows the connection between the flexible circuit board and the display panel;

[0037] Figure 5 is a schematic plan view of a flexible circuit board according to some exemplary embodiments of the present disclosure;

[0038] Figure 6 The flexible circuit board according to the embodiment of the present disclosure is Figure 5 A cross-sectional view taken along line II-II';

[0039] Figure 7 is a cross-sectional view of a first sub-body region included in a flexible circuit board according to an embodiment of the present disclosure, which schematically shows a four-layer board structure of the first sub-body region;

[0040] Figure 8 is a cross-sectional view of a first sub-body region included in a flexible circuit board according to an embodiment of the present disclosure, which schematically shows a six-layer board structure of the first sub-body region;

[0041] 9A to 9F for Figure 8 The hierarchical routing diagram of the six-layer board structure shown;

[0042] Fig. 10A and Fig. 10B is a cross-sectional view of a first sub-body region included in a flexible circuit board according to other embodiments of the present disclosure, schematically showing a six-layer board structure of the first sub-body region;

[0043] Fig.11 is a cross-sectional view of a second sub-body region included in a flexible circuit board according to an embodiment of the present disclosure, which schematically shows a double-layer board structure of the second sub-body region;

[0044] Fig.12 is a cross-sectional view of a second sub-body region included in a flexible circuit board according to an embodiment of the present disclosure, which schematically shows a single-layer board structure of the second sub-body region;

[0045] Fig.13 is a schematic plan view of a flexible circuit board according to other embodiments of the present disclosure;

[0046] Fig.14 is a cross-sectional view of a protruding area included in a flexible circuit board according to an embodiment of the present disclosure, schematically showing a double-layer board structure of the protruding area;

[0047] Fig.15 is a cross-sectional view of a protruding area included in a flexible circuit board according to an embodiment of the present disclosure, which schematically shows a single-layer board structure of the protruding area;

[0048] Fig.16 is a cross-sectional view of a binding area included in a flexible circuit board according to an embodiment of the present disclosure, which schematically shows a double-layer board structure of the binding area;

[0049] Fig.17 is a cross-sectional view of a binding area included in a flexible circuit board according to an embodiment of the present disclosure, which schematically shows a single-layer board structure of the binding area;

[0050] Fig.18 The display device according to the embodiment of the present disclosure is Figure 1 A local enlarged view of part III;

[0051] Fig.19 yes Fig.18 A schematic plan view of a display device is shown;

[0052] Fig. 20 yes Fig.13 A partial plan view of a display device of the illustrated embodiment;

[0053] Fig.21 is a cross-sectional view of a first sub-body region and a second sub-body region included in a flexible circuit board according to an embodiment of the present disclosure;

[0054] Fig. 22is a cross-sectional view of a first sub-body region and a second sub-body region included in a flexible circuit board according to an embodiment of the present disclosure;

[0055] Fig.23 is a cross-sectional view of a first sub-body region and a second sub-body region included in a flexible circuit board according to an embodiment of the present disclosure;

[0056] Fig.24 is a cross-sectional view of a main body area and a protruding area included in a flexible circuit board according to an embodiment of the present disclosure;

[0057] Fig.25 is a cross-sectional view of a main body area and a protruding area included in a flexible circuit board according to an embodiment of the present disclosure; and

[0058] Fig.26 is a cross-sectional view of a first sub-body region and a second sub-body region included in a flexible circuit board according to some exemplary embodiments of the present disclosure. DETAILED DESCRIPTION

[0059] 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.

[0060] 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.

[0061] In this document, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0062] Herein, unless otherwise specifically stated, the expressions "multilayer board", "multilayer board structure" and the like refer to a board having a stacked structure including three or more layers.

[0063] In this document, unless otherwise clearly specified or limited, the term “extending continuously” means that one component extends from another component, or that the two components are formed as a whole.

[0064] An embodiment of the present disclosure provides a flexible circuit board, the flexible circuit board comprising:

[0065] A main body area, the main body area including at least one driving device and a plurality of routing lines;

[0066] a binding region coupled to the first side of the main body region, the binding region comprising a plurality of binding pins; and

[0067] an extended area, the extended area being combined with a second side of the main body area, the first side and the second side being two opposite sides of the main body area,

[0068] The main body region includes a first sub-main body region and a second sub-main body region, the second sub-main body region is located on a side of the first sub-main body region close to the extension region, the plurality of routing lines at least include a first routing line, a second routing line and a third routing line, the first routing line, the second routing line and the third routing line all extend in the first sub-main body region, and the first routing line and the second routing line extend in the second sub-main body region; and

[0069] The first sub-body region has a multi-layer board structure, the second sub-body region has a single-layer board or a double-layer board structure, and the thickness of the second sub-body region is smaller than that of the first sub-body region.

[0070] By designing a thinned portion of the main body area, an avoidance design can be achieved so that components such as batteries and middle frame components can extend below the flexible circuit board. This is conducive to placing large-capacity batteries or avoiding the components.

[0071] It should be understood that a variety of signal routing lines can usually be integrated on a flexible circuit board for transmitting different types of signals. When the number and types of signal routing lines on a flexible circuit board are large, for example, when a variety of signal routing lines for display signals, touch signals, fingerprint recognition signals, etc. are required at the same time, the wiring difficulty in the flexible circuit board will also increase. In this regard, at least a portion of the flexible circuit board can be formed to have a multi-layer routing layer, such as a four-layer or six-layer routing layer, etc., so as to facilitate the arrangement of a variety of routing lines, so that a variety of routing lines can be distributed on different layers, thereby reducing the mutual interference between different types of routing lines. In addition, in the process of making a flexible circuit board with a multi-layer routing layer, it is also necessary to form an insulating layer (and a corresponding adhesive layer) located between adjacent routing layers. If necessary, in order to avoid signal crosstalk between different routing lines, it is also necessary to form an (electromagnetic signal) shielding layer between different routing lines.

[0072] The embodiments of the present disclosure provide a display device, and the type of the display device is not limited, and may be a liquid crystal display device (Liquid Crystal Display, LCD for short) or an electroluminescent display device. In the case where the display device is an electroluminescent display device, the electroluminescent display device may be an organic light-emitting diode (OLED for short) or a quantum dot light-emitting diode (QLED for short).

[0073] Figure 1 FIG. 4 shows a schematic diagram of the display device. Figure 1 As shown, the main structure of the display device includes components such as a frame 1, a cover plate 2, a display panel 3, and a flexible circuit board 4. In the case where the display device is a liquid crystal display device, the display device also includes a backlight assembly. Here, the display panel 3 can be a flexible display panel or a rigid display panel. In the case where the display panel 3 is a flexible display panel, the display device is a flexible display device.

[0074] For example, Figure 1 The upper side of the display panel 3 shown in the figure is the display side, and the lower side is the non-display side; at this time, the flexible circuit board 4 is placed on the non-display side of the display panel 3 after being bound. In one embodiment of the present disclosure, after the flexible circuit board 4 is bound and connected to the display panel 3, the binding end of the display panel 3 is bent toward the non-display side, so that the flexible circuit board 4 is located on the non-display side of the display panel 3, that is, the back side of the display panel 3, so as to realize the narrow frame design of the display screen.

[0075] For example, the display device provided in the embodiments of the present disclosure may be a product or component having any display function, such as a television, a digital camera, a mobile phone, and a tablet computer.

[0076] like Figure 1 As shown, the longitudinal section of the frame 1 is U-shaped, the display panel 3, the flexible circuit board 4 and other accessories are all arranged in the frame 1, the flexible circuit board 4 is placed below the display panel 3 (i.e., the back side, the side away from the display surface of the display panel 3), and the cover plate 2 is arranged on the side of the display panel 3 away from the flexible circuit board 4. In the case where the display is a liquid crystal display, and the liquid crystal display includes a backlight assembly, the backlight assembly is arranged between the display panel 3 and the flexible circuit board 4.

[0077] like Figure 1 As shown, the display panel 3 may include a display unit 31 and a touch layer 32, and the touch layer 32 may be arranged on the light-emitting side of the display unit 31. For example, when the display panel 3 is an OLED display panel, the touch layer 32 may be arranged on the encapsulation layer of the OLED display panel (it may be directly in contact with the encapsulation layer, or may be separated from the encapsulation layer by other layers, such as a flat layer, etc.), wherein the encapsulation layer may be an encapsulation substrate or an encapsulation film; when the display panel 3 is a liquid crystal display panel, the touch layer 32 may be embedded in the liquid crystal layer (i.e., In cell); or, the touch layer 32 may be arranged between the color film substrate and the upper polarizer (i.e., On cell). The position of the touch layer 32 is not limited thereto, and for example, it may also be arranged on the side of the cover plate 2 close to the display panel 3.

[0078] Figure 2 This is a partially exploded schematic diagram of a display device provided by an embodiment of the present disclosure. Figure 1 and Figure 2 The display unit 31 may include a display area AA and a non-display area NA located at least on one side of the display area AA. Figure 2 Take the non-display area NA surrounding the display area AA as an example. The display area AA can be defined as an area in which an image is displayed, and the display area AA includes a plurality of sub-pixels for realizing an image. The non-display area NA can be defined as an area in which an image is not displayed, and the non-display area NA is used for wiring. For example, a gate driving circuit can be set in the non-display area NA.

[0079] In the case where the display panel 3 includes a touch layer 32, the touch layer 32 can be disposed on the display unit 31. The touch layer 32 can obtain coordinate information from external input (e.g., a user's finger touch), that is, the touch layer 32 can be a touch panel that senses the user's touch; or it can be a fingerprint sensing panel that obtains fingerprint information of the user's finger. For example, the touch layer 32 can sense external input in a capacitive manner. It should be noted that the sensing method of the touch layer 32 in the embodiment of the present disclosure includes but is not limited to the above-mentioned implementation method, and other suitable sensing methods should be within the protection scope of the embodiment of the present disclosure.

[0080] Figure 3A and Figure 3B The display device of the embodiment of the present disclosure is respectively Figure 2 In some embodiments, reference Figure 3A The touch layer 32 can be formed on the display unit 31 through a continuous process. Here, the expression "continuous process" can be understood as: the touch layer 32 can be directly formed on the display unit 31 after the display unit 31 is formed, rather than separately forming the display unit 31 and the touch layer 32, and then setting the touch layer 32 on the display unit 31 through a process such as lamination. Figure 3A For example, when the touch layer 32 is formed in the electroluminescent display device, the touch layer 32 can be directly formed on the encapsulation layer 33. In addition, in order to avoid damaging the encapsulation layer 33 when the touch layer 32 is formed on the encapsulation layer 33, a buffer layer 34 can be formed on the encapsulation layer 33 before the touch layer 32 is formed on the encapsulation layer 33. In other embodiments, refer to Figure 3B , the touch layer 32 may be formed as a separate element, and the touch layer 32 may be adhered to the display unit 31 using the adhesive layer 35. In the case where the touch layer 32 is formed as a separate element (e.g., a separate film layer), the touch layer 32 may further include a carrier film for carrying the touch electrodes. Figure 3B In the illustrated embodiment, the touch layer 32 may include a touch electrode layer 321 and a carrying film 320 carrying the touch electrode layer.

[0081] For example, the carrier film 320 may be a resin film, a glass substrate, a composite film, etc.; the adhesive layer 35 may be a pressure sensitive adhesive (PSA), an optically clear adhesive (OCA), an optically clear resin (OCR), etc.

[0082] It should be noted that in Figure 2In the illustrated embodiment, the display panel 3 may be rectangular in the shape of the plan view. The "rectangle" here includes not only a substantially rectangular shape, but also a shape similar to a rectangle in consideration of process conditions. On this basis, the display panel 3 has a long side and a short side. In some embodiments, the long side and the short side of the display panel 3 are right angles at each intersecting position (i.e., at the corner). In other embodiments, the corners of the display panel 3 are curved, i.e., the corners are smooth.

[0083] In combination with the above embodiments, refer again to Figure 2 , the touch layer 32 may overlap the display unit 31. In some embodiments, the touch layer 32 may have substantially the same size as the display unit 31, that is, Figure 3A and Figure 3B As shown, the edge of the touch layer 32 can be aligned with the edge of the display unit 31, but the embodiment of the present disclosure is not limited thereto. Optionally, the touch layer 32 can only partially overlap with the display unit 31, for example, the touch layer 32 at least partially overlaps with the display area AA of the display unit 31.

[0084] It should be noted that the touch layer 32 includes a touch area B1 provided with a plurality of touch electrodes and a peripheral area B2 provided at the periphery of the touch area B1 and provided with touch leads electrically connected to the touch electrodes. When the touch layer 32 has substantially the same size as the display unit 31, the touch area B1 corresponds to the display area AA, and the peripheral area B2 corresponds to the non-display area NA.

[0085] On this basis, if Figure 2 As shown, the cover plate 2 may include a light-transmitting area C1 and a light-shielding area C2. The light-transmitting area C1 may at least partially overlap with the display area AA of the display unit 31, and the light-transmitting area C1 may allow light generated from the display unit 31 to pass to the outside so as to be seen by human eyes. The light-shielding area C2 may be arranged at the periphery of the light-transmitting area C1, and may at least partially overlap with the non-display area NA of the display unit 31.

[0086] Figure 4 is a schematic plan view of a flexible circuit board according to some exemplary embodiments of the present disclosure, which shows the connection between the flexible circuit board and the display panel. Figure 5 1 is a schematic plan view of a flexible circuit board according to some exemplary embodiments of the present disclosure. Figure 2 , Figure 4 and Figure 5 As shown, a portion of the display panel can be bent along line AX toward the non-display side of the display panel 3, so that the flexible circuit board 4 is located on the back of the display panel 3. The flexible circuit board 4 may include a binding area 41, a main body area 42, and an extension area 43. The binding area 41 and the extension area 43 are respectively located on both sides of the main body area 42.

[0087] The binding area 41 of the flexible circuit board 4 may include a plurality of binding pins 411. The non-display area NA of the display panel 3 may include a plurality of binding pads. The plurality of binding pins 411 are respectively bound to the plurality of binding pads to achieve binding of the flexible circuit board 4 and the display panel 3.

[0088] For example, in some embodiments, in combination Figure 4 As shown, the non-display area NA of the display panel 3 also includes a driving circuit IC37. The data signal sent by the mainboard is electrically connected to the driving circuit IC37 through the wiring on the flexible circuit board 4 (for example, it can be collectively referred to as a data signal control line), processed by the driving circuit IC37, and finally output to the display panel 3, thereby driving the display panel 3 to display.

[0089] The main area 42 of the flexible circuit board 4 may include one or more driving devices, such as a display driving device D1 and / or a touch driving device D2. The main area 42 of the flexible circuit board 4 may also include one or more traces, for example, the traces may include a first trace L1, a second trace L2, and a third trace L3. Exemplarily, the first trace L1 may be a signal trace for transmitting data required for display, the second trace L2 may be a power trace L2, and the third trace L3 may be a touch trace L3. The signal trace L1 may be electrically connected to the display driving device D1, and the touch trace L3 may be electrically connected to the touch driving device D2.

[0090] It should be noted that Figure 4 The display driver device D1 and the touch driver device D2 are schematically shown using a rectangular frame, but this should not be regarded as a limitation on the shapes of the display driver device D1 and the touch driver device D2. In addition, in the embodiment of the present disclosure, only the display driver device D1 and the touch driver device D2 are used as examples to describe the main area 42 of the flexible circuit board 4 to illustrate that electronic components and various wirings can be set in the main area 42. It should be understood that the electronic components set in the main area 42 of the flexible circuit board 4 are not limited to the display driver device D1 and the touch driver device D2. For example, in the area corresponding to the touch driver device D2, a touch IC, a touch driver element related to a touch drive signal, and other touch elements related to a touch sensing signal can be set.

[0091] For example, the driver device may include a driver IC chip. There are many ways (i.e., packaging methods) to combine the driver IC chip with the flexible circuit board 4, such as tape carrier package (TCP), chip on film (COF) packaging, etc. In the TCP method, the flexible circuit board includes a plurality of contact pads, and the plurality of pins of the driver IC chip are welded one-to-one with the plurality of contact pads of the flexible circuit board (e.g., eutectic welding), or are electrically connected one-to-one through anisotropic conductive adhesive (ACF), and at least the welding part is protected by, for example, epoxy resin; in order to increase the bendability of the flexible circuit board under the TCP method, a slit (Slit) may be formed in the packaging part. In the COF packaging method, the flexible circuit board includes a plurality of contact pads, and the plurality of pins of the driver IC chip are directly crimped on the plurality of contact pads of the flexible circuit board through the ACF, so that the plurality of pins of the driver IC chip are electrically connected one-to-one with the plurality of contact pads of the flexible circuit board. For example, the size and arrangement of the contact pads on the flexible circuit board used to combine the driver IC chip can be adjusted accordingly according to different types of packaging methods or driver IC chips to be packaged. For example, these contact pads can be arranged in a long strip or a rectangle. The embodiments of the present disclosure do not limit the packaging method of the driver IC chip.

[0092] It should be noted that the number of the first line L1, the second line L2 and the third line L3 is not limited, and may be one or more. Here, “more than one” may be, for example, at least two.

[0093] Continue to refer to Figure 4 and Figure 5 , one or more traces included in the main area 42 can extend to the extension area 43, and be electrically connected to the mainboard through the binding area or gold fingers included in the extension area 43. For example, the first trace L1 and the second trace L2 can both extend to the extension area 43. In this way, the data signal, power signal, etc. sent by the mainboard can be transmitted to the display panel 3 through the traces on the flexible circuit board 4.

[0094] Figure 6 The flexible circuit board according to the embodiment of the present disclosure is Figure 5 A cross-sectional view taken along line II-II' in FIG. Figure 5 and Figure 6 The main body area 42 of the flexible circuit board 4 includes a first sub-main body area 421 and a second sub-main body area 422. The first sub-main body area 421 is thicker than the second sub-main body area 422.

[0095] It should be noted that, in this document, unless otherwise specifically described or limited, the term “thickness” refers to a dimension along a direction perpendicular to a display surface of a display panel.

[0096] In some embodiments, the first sub-main area 421 has a multi-layer board structure, for example, the first sub-main area 421 has a four-layer board or a six-layer board structure. The second sub-main area 422 has a single-layer board or a double-layer board structure. It should be noted that the embodiment of the present disclosure does not impose any particular restriction on the number of layers of the first sub-main area 421 and the second sub-main area 422. In the embodiment of the present disclosure, the number of layers of the first sub-main area 421 is greater than the number of layers of the second sub-main area 422, so that the second sub-main area 422 is formed as a thinned area relative to the first sub-main area 421.

[0097] Figure 7 FIG. 1 is a cross-sectional view of a first sub-body region of a flexible circuit board according to an embodiment of the present disclosure, which schematically shows a four-layer board structure of the first sub-body region. Figure 7 As shown, the first sub-main area 421 may include a first sub-circuit board 51 and a second sub-circuit board 52. For example, each sub-circuit board may be a copper clad laminate. The first sub-circuit board 51 may include a substrate film 511, a conductive film 512 disposed on opposite sides of the substrate film 511, and an adhesive layer 513 disposed on one side of the substrate film 511. The second sub-circuit board 52 may include a substrate film 521 and a conductive film 522 disposed on opposite sides of the substrate film 521. The adhesive layer 513 may be disposed between the first sub-circuit board 51 and the second sub-circuit board 52. For example, the first sub-circuit board 51 may include an adhesive layer 513, and the adhesive layer 513 may be disposed on a side of the first sub-circuit board 51 close to the second sub-circuit board 52. Optionally, the adhesive layer may also be disposed on a side of the second sub-circuit board 52 close to the first sub-circuit board 51. In this way, the first sub-circuit board, the protective film, and the second sub-circuit board are bonded together by the adhesive layer 513.

[0098] Continue to refer to Figure 7 The first sub-circuit board 51 and the second sub-circuit board 52 may include an insulating film layer 59 and a protective film 53, respectively. For example, the insulating film layer 59 of the first sub-circuit board 51 is arranged on a side away from the second sub-circuit board 52, and the insulating film layer 59 of the second sub-circuit board 52 is arranged on a side away from the first sub-circuit board 51. For example, the protective films 53 of the first sub-circuit board 51 and the second sub-circuit board 52 may be arranged on a side of the respective insulating film layers 59 away from the substrate film, so as to protect the internal film layers.

[0099] It should be noted that the embodiments of the present disclosure are not limited to Figure 7 In the embodiment shown, for example, in other embodiments, according to the needs of practical applications, the protective film 53 may also be disposed between two sub-circuit boards.

[0100] Figure 8FIG. 1 is a cross-sectional view of a first sub-body region of a flexible circuit board according to an embodiment of the present disclosure, which schematically shows a six-layer board structure of the first sub-body region. Figure 8 As shown, the first sub-main area 421 may include a first sub-circuit board 51, a second sub-circuit board 52 and a third sub-circuit board 54. For example, each sub-circuit board may be a copper clad board. The first sub-circuit board 51 may include a substrate film 511, a conductive film 512 disposed on opposite sides of the substrate film 511, and an insulating film layer 59 disposed on one side of the substrate film 511. The second sub-circuit board 52 may include a substrate film 521, a conductive film 522 disposed on opposite sides of the substrate film 521, and an adhesive layer 523 disposed on both sides of the substrate film 521. The third sub-circuit board 54 may include a substrate film 541, a conductive film 542 disposed on opposite sides of the substrate film 541, and an insulating film layer 59 disposed on one side of the substrate film 541. One adhesive layer 523 may be disposed between the first sub-circuit board 51 and the second sub-circuit board 52, and another adhesive layer 523 may be disposed between the second sub-circuit board 52 and the third sub-circuit board 54. In this way, the first sub-circuit board, the second sub-circuit board and the third sub-circuit board are bonded together by the adhesive layer 523.

[0101] Continue to refer to Figure 8 The first sub-circuit board 51 and the third sub-circuit board 54 may include an insulating film layer 59 and a protective film 53, respectively. For example, the insulating film layer 59 of the first sub-circuit board 51 is arranged on a side away from the second sub-circuit board 52, and the insulating film layer 59 of the third sub-circuit board 54 is arranged on a side away from the second sub-circuit board 52. For example, the protective films 53 of the first sub-circuit board 51 and the third sub-circuit board 54 may be arranged on a side of the respective insulating film layers 59 away from the substrate film, so as to protect the internal film layers.

[0102] It should be noted that the embodiments of the present disclosure are not limited to Figure 8 In the embodiment shown, for example, in other embodiments, according to the needs of practical applications, the protective film 53 may also be disposed between two sub-circuit boards.

[0103] For example, the substrate film may be made of flexible materials such as polyimide or polyester, and the conductive film may be made of conductive metal materials such as copper.

[0104] In this document, unless otherwise specified and limited, the number of layers in the expressions "single-layer board", "double-layer board", "four-layer board", "six-layer board", etc. refers to the number of layers of conductive films in the flexible circuit board. For example, a "single-layer board" is provided with one layer of conductive film, a "double-layer board" is provided with two layers of conductive films, a "four-layer board" is provided with four layers of conductive films, and a "six-layer board" is provided with six layers of conductive films.

[0105] 9A to 9Ffor Figure 8 The schematic diagram of the hierarchical routing of the six-layer board structure shown in the figure. Figure 8 9 , the six-layer board structure of the first sub-body region 421 may include six conductive films. For the convenience of description, in FIG. 9 , the six conductive films are respectively described as a first layer AL1 , a second layer AL2 , a third layer AL3 , a fourth layer AL4 , a fifth layer AL5 and a sixth layer AL6 .

[0106] The first layer AL1 includes driving devices D1, D2 and device routing electrically connected to the driving devices D1, D2. For example, the device routing may be a part of the first routing L1 and a part of the third routing L3. The second layer AL2 includes a power routing L2. The third layer AL3 includes a portion of touch routing and a portion of power routing. For example, the third routing L3 may include an Rx routing L31 for a touch function, and the Rx routing L31 is used to transmit signals to a touch receiving electrode. Part of the touch routing may include the Rx routing L31. The fourth layer AL4 and the fifth layer AL5 may include other types of routing L4. The sixth layer AL6 includes a portion of touch routing. For example, the third routing L3 may also include a Tx routing L32 for a touch function, and the Tx routing L32 is used to transmit signals to a touch sending electrode. Part of the touch routing may include the Tx routing L32.

[0107] It should be noted that the arrangement of the above components and routing is only exemplary and is not a limitation to the embodiments of the present disclosure. In other embodiments, the components and routing arranged on each layer may be adjusted according to actual needs. For example, routing may not be arranged in some conductive layers. For example, in the fourth layer AL4 and the fifth layer AL5, no routing may be arranged, but a shielding layer may be arranged.

[0108] For example, the above-mentioned binding area 41 and the binding pin 411 may be disposed in the second layer AL2.

[0109] The Rx line L31 and Tx line L32 of the power line L2 and the touch line L3 are located on the second layer, the third layer and the sixth layer respectively, and the orthographic projections of the power line L2 and the touch line L3 on the substrate film intersect with each other. In the above embodiment, the shielding between the power line L2 and the touch line L3 is achieved by the shielding layer of the fourth layer AL4 and the fifth layer AL5. For example, the shielding layer of the fourth layer AL4 and the fifth layer AL5 may include a metal material, and the shielding layer may be suspended or configured to be electrically connected to the ground wire. In this way, signal interference between the power line L2 and the touch line L3 can be avoided. In practical applications, the shielding layer can be set accordingly according to the number of layers of the flexible circuit board and the actual wiring layout.

[0110] Return to reference Figure 8The six-layer board structure of the first sub-main area 421 includes three sub-circuit boards, each of which includes two layers of conductive film, that is, the six-layer board structure of the first sub-main area 421 has a "2 layers + 2 layers + 2 layers" combination mode.

[0111] Optionally, the six-layer board structure of the first sub-body area 421 may have a combination mode of “1 layer+2 layers+2 layers+1 layer”. Fig. 10A FIG. 1 is a cross-sectional view of a first sub-body region of a flexible circuit board according to some other embodiments of the present disclosure, which schematically shows a six-layer board structure of the first sub-body region. Fig. 10A As shown, the first sub-main area 421 may include a first sub-circuit board 51, a second sub-circuit board 52, a third sub-circuit board 54 and a fourth sub-circuit board 55. For example, each sub-circuit board may be a copper clad laminate. The first sub-circuit board 51 may include a substrate film 511, a conductive film 512 disposed on one side of the substrate film 511, and an adhesive layer 513 disposed on a side of the conductive film 512 away from the substrate film 511. The second sub-circuit board 52 may include a substrate film 521, a conductive film 522 disposed on opposite sides of the substrate film 521, and an adhesive layer 523 disposed on a side of the conductive film 522 away from the substrate film 521. The third sub-circuit board 54 may include a substrate film 541 and a conductive film 542 disposed on opposite sides of the substrate film 541. The fourth sub-circuit board 55 may include a substrate film 551, a conductive film 552 disposed on one side of the substrate film 551, and an adhesive layer 553 disposed on a side of the conductive film 552 away from the substrate film 551. The adhesive layer 513 may be disposed between the first sub-circuit board 51 and the second sub-circuit board 52, and the adhesive layer 523 may be disposed between the second sub-circuit board 52 and the third sub-circuit board 54. For example, the adhesive layer 513 of the first sub-circuit board may be disposed on a side close to the second sub-circuit board 52, and the adhesive layer 523 of the second sub-circuit board may be disposed on a side close to the third sub-circuit board 54. The adhesive layer 553 of the fourth sub-circuit board may be disposed on a side close to the third sub-circuit board 54. In this way, the first sub-circuit board, the second sub-circuit board, the third sub-circuit board and the fourth sub-circuit board are bonded together by the adhesive layers 513, 523, 553.

[0112] Continue to refer to Fig. 10A The first sub-circuit board 51 and the fourth sub-circuit board 55 may respectively include a protective film 53 . For example, the protective film 53 of the first sub-circuit board 51 is arranged on a side away from the second sub-circuit board 52 , and the protective film 53 of the fourth sub-circuit board 55 is arranged on a side away from the third sub-circuit board 54 .

[0113] It should be noted that the embodiments of the present disclosure are not limited to Fig. 10AIn the embodiment shown in FIG. 1 , for example, in other embodiments, the protective film 53 may also be disposed between two sub-circuit boards according to the needs of practical applications. Fig. 10B The protective film 53 may be disposed between the first sub-circuit board 51 and the second sub-circuit board 52 , between the second sub-circuit board 52 and the third sub-circuit board 54 , and between the third sub-circuit board 54 and the fourth sub-circuit board 55 , respectively.

[0114] Fig.11 FIG. 1 is a cross-sectional view of the second sub-body region of the flexible circuit board according to an embodiment of the present disclosure, which schematically shows the double-layer board structure of the second sub-body region. Fig.11 As shown, the second sub-body area 422 has a double-layer board structure, which may include a double-layer sub-circuit board 56. For example, the double-layer sub-circuit board 56 may be a copper-clad board. The double-layer sub-circuit board 56 may include a substrate film 561, a conductive film 562 disposed on opposite sides of the substrate film 561, and an adhesive layer 563 disposed on the conductive film 562 on both sides away from the substrate film 561.

[0115] Fig.21 FIG. 1 is a cross-sectional view of a first sub-body region and a second sub-body region included in a flexible circuit board according to an embodiment of the present disclosure. Figure 8 , Fig.11 and Fig.21 In the case where the six-layer board structure of the first sub-body area 421 adopts a "2-layer + 2-layer + 2-layer" layout, the double-layer sub-circuit board 56 of the second sub-body area 422 can be composed of Figure 8 The first sub-circuit board 51, the second sub-circuit board 52 and the third sub-circuit board 54 are led out. That is, the double-layer sub-circuit board 56 of the second sub-body area 422 is connected to the Figure 8 One of the first sub-circuit board 51, the second sub-circuit board 52 and the third sub-circuit board 54 is continuously extended. Fig.21 In the illustrated embodiment, the film layers 561, 562, 563 on the double-layer sub-circuit board 56 are respectively extended from the film layers 521, 522, 523 on the second sub-circuit board 52. In this way, the process of forming the main body area can be simplified.

[0116] Fig. 22 FIG. 1 is a cross-sectional view of a first sub-body region and a second sub-body region included in a flexible circuit board according to an embodiment of the present disclosure. Fig. 10A , Fig.11 and Fig. 22 In the case where the six-layer board structure of the first sub-body area 421 adopts the "1 layer + 2 layers + 2 layers + 1 layer" layout, the double-layer sub-circuit board 56 of the second sub-body area 422 can be composed of Fig. 10AThat is, the double-layer sub-circuit board 56 of the second sub-main area 422 is connected to one of the second sub-circuit board 52 and the third sub-circuit board 54. Fig. 10A One of the second sub-circuit board 52 and the third sub-circuit board 54 is continuously extended. Fig. 22 In the illustrated embodiment, the film layers 561, 562 on the double-layer sub-circuit board 56 are respectively extended from the film layers 541, 542 on the third sub-circuit board 54. The adhesive layer 563 may be extended from the adhesive layers 523, 553 located on both sides of the third sub-circuit board 54. In this way, the process of forming the main body area can be simplified.

[0117] In some exemplary embodiments, the conductive film 562 located on the upper side of the double-layer sub-circuit board 56 forms a first conductive layer, and the conductive film 562 located on the lower side of the double-layer sub-circuit board 56 forms a second conductive layer. For example, the first conductive layer may include a signal trace and a power trace, namely the first trace L1 and the second trace L2 mentioned above. The second conductive layer may also include a signal trace and a power trace, namely the first trace L1 and the second trace L2 mentioned above. Optionally, the second conductive layer may include a shielding layer, for example, the shielding layer may include a metal material, and the shielding layer may be suspended, or configured to be electrically connected to a ground line.

[0118] Fig.12 FIG. 1 is a cross-sectional view of a second sub-body region included in a flexible circuit board according to an embodiment of the present disclosure, which schematically shows a single-layer board structure of the second sub-body region. Fig.12 As shown, the second sub-body area 422 has a single-layer board structure, which may include a single-layer sub-circuit board 57. For example, the single-layer sub-circuit board 57 may be a copper-clad board. The single-layer sub-circuit board 57 may include a substrate film 571, a conductive film 572 disposed on one side of the substrate film 571, and an adhesive layer 573 disposed on a side of the conductive film 572 away from the substrate film 571.

[0119] Fig.23 FIG. 1 is a cross-sectional view of a first sub-body region and a second sub-body region included in a flexible circuit board according to an embodiment of the present disclosure. Fig. 10A , Fig.12 and Fig.23 In the case where the six-layer board structure of the first sub-body area 421 adopts the "1 layer + 2 layers + 2 layers + 1 layer" layout, the single-layer sub-circuit board 57 of the second sub-body area 422 can be composed of Fig. 10A That is, the single-layer sub-circuit board 57 of the second sub-body area 422 is connected to one of the first sub-circuit board 51 and the fourth sub-circuit board 55. Fig. 10A One of the first sub-circuit board 51 and the fourth sub-circuit board 55 is continuously extended. Fig.23In the illustrated embodiment, the film layers 571, 572, 573 on the single-layer sub-circuit board 57 are respectively extended from the film layers 511, 512, 513 on the first sub-circuit board 51. In this way, the process of forming the main body area can be simplified.

[0120] In some exemplary embodiments, the conductive film 572 of the single-layer sub-circuit board 57 may include a signal trace and a power trace, namely, the first trace L1 and the second trace L2 mentioned above.

[0121] Return to reference Figure 5 , the orthographic projection of the combination of the first sub-main area 421 and the second sub-main area 422 (i.e., the entire main area 42) on the display panel or the substrate film has a rectangular shape. The "rectangle" here not only includes the shape of a basic rectangle, but also includes a shape similar to a rectangle in consideration of the process conditions. On this basis, the main area 42 has a long side and a short side. In some embodiments, the long side and the short side of the main area 42 are right angles at each intersecting position (i.e., the corner). In other embodiments, the corners of the main area 42 are curved, i.e., the corners are smooth.

[0122] like Figure 5 As shown, the direction in which the short side of the main body area 42 extends is defined as the first direction A1, and the direction in which the long side extends is defined as the second direction A2. The size of the main body area 42 along the first direction A1 is H, the size of the first sub-main body area 421 along the first direction A1 is H1, and the size of the second sub-main body area 422 along the first direction A1 is H2. The size of the first sub-main body area 421 along the second direction A2 is W1, and the size of the second sub-main body area 422 along the second direction A2 is W2.

[0123] In the embodiment of the present disclosure, the area of ​​the orthographic projection of the main body area 42 on the display panel or the substrate film is associated with the area of ​​the orthographic projection of the first sub-main body area 421 on the display panel or the substrate film. For example, as the area of ​​the first sub-main body area 421 decreases, the area of ​​the main body area 42 needs to be increased. In other words, when the area of ​​the first sub-main body area 421 with a six-layer board structure decreases, the area of ​​the entire main body area 42 needs to be increased, that is, the area of ​​the second sub-main body area 422 needs to be increased, so that sufficient wiring area is still guaranteed to arrange the above-mentioned multiple routing lines.

[0124] In some embodiments, the size H of the main body region 42 is associated with the size H1 of the first sub-main body region 421. For example, as the size H1 of the first sub-main body region 421 decreases, the size H of the main body region 42 needs to increase. For example, the ratio of the size H of the main body region 42 to the size H1 of the first sub-main body region 421 can be between 1.5 and 5. For example, the size H1 of the first sub-main body region 421 can be within 5 to 10 mm, such as about 7 mm; the size H of the main body region 42 can be within 7 to 20 mm, such as about 12 mm.

[0125] It should be noted that the minimum value of the size H1 of the first sub-body area 421 needs to meet the signal shielding requirement. In the above exemplary embodiment, the minimum value of the size H1 of the first sub-body area 421 is set to about 5 mm to meet the signal shielding requirement.

[0126] Continue to refer to Figure 5 , the size W1 of the first sub-body area 421 is substantially equal to the size W2 of the second sub-body area 422. That is, the orthographic projection of each of the first sub-body area 421 and the second sub-body area 422 on the display panel or the substrate film has a rectangular shape. By designing such a regular shape, it is convenient to realize the process of forming the first sub-body area and the second sub-body area.

[0127] In the embodiment of the present disclosure, the shape and position of the second sub-body area 422 can be designed according to actual avoidance requirements. Fig.13 Schematic diagram of a flexible circuit board according to other embodiments of the present disclosure. Fig.13 As shown, the size W2 of the second sub-body region 422 is smaller than the size W1 of the first sub-body region 421. For example, the size W2 of the second sub-body region 422 may be less than or equal to one half of the size W1 of the first sub-body region 421.

[0128] For example, the orthographic projection of the main body area 42 on the display panel or substrate film has a rectangular shape, the orthographic projection of the first sub-main body area 421 on the display panel or substrate film has an inverted L-shape, and the orthographic projection of the second sub-main body area 422 on the display panel or substrate film has a rectangular shape.

[0129] In the embodiment of the present disclosure, the extension area 43 of the flexible circuit board 4 may have a double-layer board structure or a single-layer board structure. For example, the extension area 43 of the flexible circuit board 4 and the second sub-body area 422 of the flexible circuit board may extend continuously.

[0130] For example, Fig.14 FIG. 1 is a cross-sectional view of a protruding area of ​​a flexible circuit board according to an embodiment of the present disclosure, which schematically shows a double-layer board structure of the protruding area. Fig.14As shown, the extension area 43 has a double-layer board structure, which may include a double-layer sub-circuit board 431. For example, the double-layer sub-circuit board 431 may be a copper-clad board. The double-layer sub-circuit board 431 may include a substrate film 4311, a conductive film 4312 disposed on opposite sides of the substrate film 4311, and an adhesive layer 4313 disposed on the conductive film 4312 on both sides away from the substrate film 4311.

[0131] The double-layer sub-circuit board 431 and the double-layer sub-circuit board 56 can be extended continuously. For example, when the six-layer board structure of the first sub-body area 421 adopts the "2 layers + 2 layers + 2 layers" layout, the double-layer sub-circuit board 431 can be composed of Figure 8 The double-layer sub-circuit board 431 is connected to one of the first sub-circuit board 51, the second sub-circuit board 52 and the third sub-circuit board 54. Figure 8 One of the first sub-circuit board 51, the second sub-circuit board 52 and the third sub-circuit board 54 is continuously extended. For another example, when the six-layer board structure of the first sub-body area 421 adopts the "1 layer + 2 layers + 2 layers + 1 layer" layout, the double-layer sub-circuit board 431 can be composed of Fig. 10A The second sub-circuit board 52 and the third sub-circuit board 54 are led out. That is, the double-layer sub-circuit board 431 and Fig. 10A One of the second sub-circuit board 52 and the third sub-circuit board 54 is continuously extended. In this way, the process of forming the main body area can be simplified.

[0132] Fig.24 is a cross-sectional view of a main body region and an extension region of a flexible circuit board according to an embodiment of the present disclosure. Fig.24 The double-layer sub-circuit board 431 can be made of Fig. 10A That is, the film layers 4311 , 4312 , 4313 on the double-layer sub-circuit board 431 extend from the film layers 521 , 522 , 523 on the second sub-circuit board 52 , respectively.

[0133] In some exemplary embodiments, the conductive film 4312 located on the upper side of the double-layer sub-circuit board 431 forms a first conductive layer, and the conductive film 4312 located on the lower side of the double-layer sub-circuit board 431 forms a second conductive layer. For example, the first conductive layer may include a signal trace and a power trace, namely the first trace L1 and the second trace L2 mentioned above. The second conductive layer may also include a signal trace and a power trace, namely the first trace L1 and the second trace L2 mentioned above. Optionally, the second conductive layer may include a shielding layer, for example, the shielding layer may include a metal material, and the shielding layer may be suspended, or configured to be electrically connected to a ground line.

[0134] Fig.15FIG. 1 is a cross-sectional view of a protruding area of ​​a flexible circuit board according to an embodiment of the present disclosure, which schematically shows a single-layer board structure of the protruding area. Fig.15 As shown, the extension area 43 has a single-layer board structure, which may include a single-layer sub-circuit board 432. For example, the single-layer sub-circuit board 432 may be a copper-clad board. The single-layer sub-circuit board 432 may include a substrate film 4321, a conductive film 4322 disposed on one side of the substrate film 4321, and an adhesive layer 4323 disposed on a side of the conductive film 4322 away from the substrate film 4321.

[0135] The single-layer sub-circuit board 432 and the above-mentioned single-layer sub-circuit board 57 can be extended continuously. For example, when the six-layer board structure of the first sub-body area 421 adopts the "1 layer + 2 layers + 2 layers + 1 layer" layout, the single-layer sub-circuit board 432 can be composed of Fig. 10A The single-layer sub-circuit board 432 is connected to one of the first sub-circuit board 51 and the fourth sub-circuit board 55. Fig. 10A One of the first sub-circuit board 51 and the fourth sub-circuit board 55 is continuously extended. In this way, the process of forming the extended area can be simplified.

[0136] Fig.25 is a cross-sectional view of a main body region and an extension region of a flexible circuit board according to an embodiment of the present disclosure. Fig.25 , the single-layer sub-circuit board 432 can be composed of Fig. 10A That is, the film layers 4321 , 4322 , 4323 on the single-layer sub-circuit board 432 are respectively extended from the film layers 511 , 512 , 513 on the first sub-circuit board 51 .

[0137] In some exemplary embodiments, the conductive film 4322 of the single-layer sub-circuit board 432 may include a signal trace and a power trace, namely, the first trace L1 and the second trace L2 mentioned above.

[0138] In the above embodiment, the extension area of ​​the flexible circuit board is designed to have a double-layer board or a single-layer board structure, so that the flexible circuit board can be easily bent in the extension area, which is beneficial for bending the flexible circuit board to the back of the display panel for electrical connection with the main board.

[0139] In some embodiments, an electromagnetic shielding layer 435 is disposed on one side (eg, a side away from the display panel) of the second sub-body region 422 and the extension region 43 of the flexible circuit board 4. Fig.18 For example, the electromagnetic shielding layer 435 can be one or more of conductive rubber, conductive cloth, conductive foam and conductive shielding glue. By setting the electromagnetic shielding layer, the interference of external signals on the signals transmitted by the wiring on the flexible circuit board can be shielded.

[0140] Fig.26 is a cross-sectional view of a first sub-body region and a second sub-body region included in a flexible circuit board according to some exemplary embodiments of the present disclosure. Fig.26 , the left part corresponds to the first sub-main area, and the right part corresponds to the second sub-main area. The first sub-main area includes substrate films 511, 521, 531, and 541. A conductive film 512 is provided on one side surface (upper side surface) of the substrate film 511, conductive films 522 are provided on both side surfaces of the substrate film 521, conductive films 532 are provided on both side surfaces of the substrate film 531, and conductive films 542 are provided on one side surface (lower side surface) of the substrate film 541. That is, the first sub-main area has six layers of conductive films, and has a combination of "1 layer + 2 layers + 2 layers + 1 layer". The second sub-main area includes a substrate film 561, and conductive films 562 are provided on both side surfaces of the substrate film 561. That is, the second sub-main area has two layers of conductive films.

[0141] In this embodiment, the second sub-main area and the first sub-main area extend continuously. Fig.26 The base film 561 is extended from the base film 531 , and the conductive film 562 is extended from the conductive film 532 .

[0142] For example, a copper layer TL is disposed on at least one of the conductive films. The above-mentioned wirings can be formed in the copper layer TL, that is, by forming the copper layer TL on the conductive film and forming the wirings through a patterning process such as a composition process.

[0143] It should be noted that in Fig.26 In the illustrated embodiment, the copper clad layer TL is disposed only on the conductive film 512, one conductive film 522, one conductive film 532 / 562, and the conductive film 542, and the copper clad layer TL is not disposed on another conductive film 522 and another conductive film 532 / 562. Such a configuration is exemplary and is not a limitation of the embodiments of the present disclosure. The conductive film corresponding to the copper clad layer can be determined according to the actual needs of the wiring layout.

[0144] Continue to refer to Fig.26 The first sub-body area and the second sub-body area may further include an electromagnetic shielding layer EMI for protecting electronic components and wiring in the first sub-body area and the second sub-body area from external electromagnetic interference.

[0145] For example, adhesive layers 513, 523, 533, 563 may be provided between the film layers. In the second sub-body region, a protective film 53 may be provided between the adhesive layer 563 and the electromagnetic shielding layer EMI.

[0146] For example, in the first sub-body region, a protective layer PTL may be disposed on the side of the adhesive layer 513 away from the substrate film. An insulating film layer 59 may be disposed between the copper cladding layer TL and the electromagnetic shielding layer EMI.

[0147] In the embodiment of the present disclosure, the binding area 41 of the flexible circuit board 4 may have a double-layer board structure or a single-layer board structure. For example, the binding area 41 of the flexible circuit board 4 may be led out from one of the sub-circuit boards in the six-layer board structure of the first sub-body area 421 .

[0148] In some embodiments, the lead-out layers of the binding area 41, the second sub-body area 422, and the extension area 43 of the flexible circuit board 4 may be the same, that is, they are all led out from the same sub-circuit board in the six-layer board structure of the first sub-body area 421. In this way, when the above-mentioned traces extend from one area to another, the traces can extend in the same layer without extending to other layers through vias, which is conducive to reducing the impedance of the traces.

[0149] For example, Fig.16 FIG. 1 is a cross-sectional view of a binding area of ​​a flexible circuit board according to an embodiment of the present disclosure, which schematically shows a double-layer board structure of the binding area. Fig.16 As shown, the binding area 41 has a double-layer board structure, which may include a double-layer sub-circuit board 411. For example, the double-layer sub-circuit board 411 may be a copper-clad board. The double-layer sub-circuit board 411 may include a substrate film 4111, a conductive film 4112 disposed on opposite sides of the substrate film 4111, and an adhesive layer 4113 disposed on the conductive film 4112 on both sides away from the substrate film 4111.

[0150] The double-layer sub-circuit board 411 and the double-layer sub-circuit board 56 can be extended continuously. For example, when the six-layer board structure of the first sub-body area 421 adopts the "2 layers + 2 layers + 2 layers" layout, the double-layer sub-circuit board 411 can be composed of Figure 8 The double-layer sub-circuit board 411 is connected to one of the first sub-circuit board 51, the second sub-circuit board 52 and the third sub-circuit board 54. Figure 8 One of the first sub-circuit board 51, the second sub-circuit board 52 and the third sub-circuit board 54 is continuously extended. For another example, when the six-layer board structure of the first sub-body area 421 adopts the "1 layer + 2 layers + 2 layers + 1 layer" layout, the double-layer sub-circuit board 411 can be composed of Fig. 10A The second sub-circuit board 52 and the third sub-circuit board 54 are led out. That is, the double-layer sub-circuit board 411 and Fig. 10A One of the second sub-circuit board 52 and the third sub-circuit board 54 is continuously extended.

[0151] Fig.17 FIG. 1 is a cross-sectional view of a binding region included in a flexible circuit board according to an embodiment of the present disclosure, which schematically shows a single-layer board structure of the binding region. Fig.17 As shown, the binding area 41 has a single-layer board structure, which may include a single-layer sub-circuit board 412. For example, the single-layer sub-circuit board 412 may be a copper-clad board. The single-layer sub-circuit board 412 may include a substrate film 4121, a conductive film 4122 disposed on one side of the substrate film 4121, and an adhesive layer 4123 disposed on a side of the conductive film 4122 away from the substrate film 4121.

[0152] The single-layer sub-circuit board 412 and the above-mentioned single-layer sub-circuit board 57 can be extended continuously. For example, when the six-layer board structure of the first sub-body area 421 adopts the "1 layer + 2 layers + 2 layers + 1 layer" layout, the single-layer sub-circuit board 412 can be composed of Fig. 10A The first sub-circuit board 51 and the fourth sub-circuit board 55 are led out. That is, the single-layer sub-circuit board 412 is connected to the Fig. 10A One of the first sub-circuit board 51 and the fourth sub-circuit board 55 is continuously extended.

[0153] In some embodiments, the lead-out layers of the binding area 41 of the flexible circuit board 4 and the second sub-body area 422 may be different. For example, the binding area 41 may be led out from the second layer AL2 of the six-layer board structure of the first sub-body area 421, and the second sub-body area 422 may be led out from the sixth layer AL6 of the six-layer board structure of the first sub-body area 421. In this embodiment, it can be ensured that the extension area of ​​the flexible circuit board extends out from the first sub-body area in a plane, which is conducive to the formation of the extension area.

[0154] Fig.18 The display device according to the embodiment of the present disclosure is Figure 1 A local enlarged view of part III. Fig.19 yes Fig.18 A schematic plan view of a display device is shown. Figure 1 , Figure 2 , Fig.18 and Fig.19 The display device may further include a battery 6. It should be noted that the term "battery" herein may include any form of power storage component, including but not limited to a lithium battery, a battery compartment with a protective shell, and the like.

[0155] The orthographic projection of the battery 6 on the display panel 3 does not overlap with the orthographic projection of the second sub-body area 422 on the display panel 3. The first sub-body area 421 has a thicker six-layer plate structure, and the battery 6 or the middle frame member 7 does not extend below the first sub-body area 421.

[0156] The orthographic projection of the battery 6 on the display panel 3 at least partially overlaps with the orthographic projection of the body area 42 on the display panel 3. For example, the orthographic projection of the battery 6 on the display panel 3 at least partially overlaps with the orthographic projection of the second sub-body area 422 on the display panel 3.

[0157] In the embodiment of the present disclosure, by designing the second sub-body area 422 to be thinner than the first sub-body area 421, the battery 6 can extend below the second sub-body area 422. In this way, the area of ​​the battery 6 equipped with the display device is increased, and accordingly, the capacity of the battery 6 can be increased.

[0158] It should be noted that the embodiments of the present disclosure are not limited to avoiding the battery 6. By designing a thinned second sub-body area 422, other components of the display device (such as a middle frame component) can be extended to the bottom of the second sub-body area, thereby achieving the purpose of avoiding the battery 6. Fig. 20 yes Fig.13 A partial plan view of a display device of the embodiment shown, as Fig. 20 As shown, the display device includes a middle frame member 7, and the middle frame member 7 can extend below the second sub-body area 422, that is, the orthographic projection of the middle frame member 7 on the display panel 3 at least partially overlaps with the orthographic projection of the second sub-body area 422 on the display panel 3. Therefore, through such a design, components such as the battery and the middle frame member can be avoided, and when the display device is a small-sized display device such as a mobile phone, such a avoidance design is particularly advantageous.

[0159] In the specific implementation process, the flexible circuit board 4 can be bent to the back of the display panel to realize the narrow frame design of the display device. The display device provided in the embodiment of the present disclosure can be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, a navigator, etc. Other essential components of the display device should be understood by ordinary technicians in the field, and will not be repeated here, nor should they be used as a limitation to the embodiment of the present disclosure.

[0160] The above is only a specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A flexible circuit board, characterized in that: The flexible circuit board comprises: A main body area, the main body area including at least one driving device and a plurality of routing lines; a binding region coupled to the first side of the main body region, the binding region comprising a plurality of binding pins; and an extended area, the extended area being combined with a second side of the main body area, the first side and the second side being two opposite sides of the main body area, The main body area includes a first sub-main body area and a second sub-main body area, and the second sub-main body area is located on a side of the first sub-main body area close to the extension area; the plurality of routing lines at least include a first routing line, a second routing line and a third routing line, and the first routing line, the second routing line and the third routing line all extend in the first sub-main body area, and the first routing line and the second routing line extend in the second sub-main body area; and The first sub-body area has a multi-layer board structure, the second sub-body area has a single-layer board or double-layer board structure, the thickness of the second sub-body area is less than the thickness of the first sub-body area; the lower part of the second sub-body area is used to place batteries or middle frame components.

2. The flexible circuit board according to claim 1, wherein: The first sub-body area has a first dimension along a first direction, the first direction is perpendicular to the thickness direction of the flexible circuit board and points from the binding area to the extension area; as well as The second sub-body region has a second size along the first direction, and a ratio of a sum of the first size and the second size to a first size of the first sub-body region is between 1.5 and 5.

3. The flexible circuit board according to claim 2, wherein: The first dimension is in the range of 5 to 10 mm; and / or the sum of the first dimension and the second dimension is in the range of 7 to 20 mm.

4. The flexible circuit board according to any one of claims 1 to 3, wherein: The first sub-body region has a four-layer plate structure.

5. The flexible circuit board according to claim 4, wherein: The first sub-body area includes a first sub-circuit board, a second sub-circuit board and a protective film. Each of the first sub-circuit board and the second sub-circuit board includes a base film and conductive films arranged on opposite sides of the base film.

6. The flexible circuit board according to any one of claims 1 to 3, wherein: The first sub-body region has a six-layer board structure.

7. The flexible circuit board according to claim 6, wherein: The first sub-main area includes a first sub-circuit board, a second sub-circuit board, a third sub-circuit board and a protective film, and each of the first sub-circuit board, the second sub-circuit board and the third sub-circuit board includes a substrate film and conductive films arranged on opposite sides of the substrate film.

8. The flexible circuit board according to claim 6, wherein: The first sub-main area includes a first sub-circuit board, a second sub-circuit board, a third sub-circuit board, a fourth sub-circuit board and a protective film, each of the first sub-circuit board and the fourth sub-circuit board includes a base film and a conductive film arranged on one side of the base film, each of the second sub-circuit board and the third sub-circuit board includes a base film and a conductive film arranged on opposite sides of the base film, and an adhesive layer is arranged between the first sub-circuit board and the second sub-circuit board, between the second sub-circuit board and the third sub-circuit board, and between the third sub-circuit board and the fourth sub-circuit board.

9. The flexible circuit board according to claim 7, wherein: The second sub-body area has a double-layer board structure, the double-layer board structure includes a double-layer sub-circuit board, and the double-layer sub-circuit board includes a substrate film and conductive films arranged on opposite sides of the substrate film.

10. The flexible circuit board according to claim 9, wherein: One of the first sub-circuit board, the second sub-circuit board and the third sub-circuit board is continuously extended with the double-layer sub-circuit board.

11. The flexible circuit board according to claim 8, wherein: The second sub-body area has a double-layer board structure, the double-layer board structure includes a double-layer sub-circuit board, and the double-layer sub-circuit board includes a substrate film and conductive films arranged on opposite sides of the substrate film.

12. The flexible circuit board according to claim 11, wherein: One of the second sub-circuit board and the third sub-circuit board is continuously extended with the double-layer sub-circuit board.

13. The flexible circuit board according to claim 8, wherein: The second sub-body area has a single-layer board structure, the single-layer board structure includes a single-layer sub-circuit board, and the single-layer sub-circuit board includes a substrate film and a conductive film arranged on one side of the substrate film.

14. The flexible circuit board according to claim 13, wherein: One of the first sub-circuit board and the fourth sub-circuit board is continuously extended with the single-layer sub-circuit board.

15. The flexible circuit board according to claim 2, wherein: The first sub-body area has a third size along a second direction, and the second sub-body area has a fourth size along the second direction, wherein the second direction is perpendicular to the thickness direction of the flexible circuit board and perpendicular to the first direction; as well as The third size is equal to the fourth size, or the third size is greater than the fourth size.

16. The flexible circuit board according to any one of claims 1 to 3, wherein: The protruding area has a double-layer plate structure or a single-layer plate structure.

17. The flexible circuit board according to claim 16, wherein: The extension region and the second sub-body region extend continuously.

18. The flexible circuit board according to claim 2, wherein: As the first size of the first sub-body area increases, the projection area of ​​the second sub-body area along the thickness direction of the flexible circuit board decreases.

19. The flexible circuit board according to claim 9, wherein: The binding area has a double-layer board structure or a single-layer board structure.

20. The flexible circuit board according to claim 19, wherein: The binding area and the second sub-body area are led out from the same sub-circuit board of the first sub-body area.

21. The flexible circuit board according to claim 19, wherein: The binding area and the second sub-body area are led out from different sub-circuit boards of the first sub-body area.

22. A display device, characterized in that: The display device comprises: Display panel; The flexible circuit board according to any one of claims 1 to 21; and Battery, Wherein, the binding area of ​​the flexible circuit board is connected to the display panel, and the flexible circuit board is located on the non-display side of the display panel; and The battery is located on a side of the flexible circuit board facing away from the display panel.

23. The display device according to claim 22, wherein: An orthographic projection of the battery on the display panel at least partially overlaps with an orthographic projection of the second sub-body area on the display panel.

24. The display device according to claim 22, wherein: The display device also includes a middle frame component, at least a portion of which is located on a side of the flexible circuit board facing away from the display panel, and an orthographic projection of the middle frame component on the display panel at least partially overlaps with an orthographic projection of the second sub-body area on the display panel.

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