Flexible circuit board and display module

Abstract

The embodiment of the application provides a flexible circuit board and a display module, the flexible circuit board comprises a substrate layer and a conductive layer, the conductive layer is arranged on one side surface of the substrate layer, the conductive layer has a plurality of gold finger structures at least at one end along a first direction, the plurality of gold finger structures comprise first gold finger structures located at the outermost two sides along a second direction, and second gold finger structures located between the first gold finger structures, at least one second gold finger structure is provided with at least one isolation groove, the second gold finger structure comprises a plurality of conductive segments along the first direction, and at least one first gold finger structure is continuously arranged along the first direction. The flexibility of the second gold finger structure can be improved, the middle region of the end of the flexible circuit board can be segmented to release stress, the problems of breakage of the second gold finger structure and peeling from the surface of the substrate layer are improved, a certain shape is maintained, use is facilitated, a reinforcing layer is not needed, the binding precision is avoided from being affected, and the flexible circuit board is more light and thin.

Description

Technical Field

[0001] This application relates to the field of display technology, and more specifically, to a flexible circuit board and a display module. Background Technology

[0002] Flexible printed circuit boards (FPCs), with their thinness, bendability, and excellent flexibility, are widely used in portable electronic products such as flexible displays, smart wearables, and foldable terminals. The gold fingers at the bonding end of the FPC, as the core signal connection structure, play a crucial role in ensuring circuit conduction and signal transmission; their structural stability directly determines the overall performance of the electronic product. However, under repeated bending conditions, the gold fingers are highly susceptible to breakage, peeling, and other damage.

[0003] There is a need to provide a solution that can easily, cost-effectively, and reliably improve the bending fracture resistance of gold fingers. Summary of the Invention

[0004] To overcome the technical problems mentioned in the above background, embodiments of this application provide a flexible circuit board, which includes: Substrate layer; and A conductive layer is disposed on one side surface of the substrate layer, and the conductive layer has a plurality of gold finger structures at at least one end along a first direction; the plurality of gold finger structures are arranged at intervals along a second direction; the plurality of gold finger structures include first gold finger structures located on the outermost two sides along the second direction, and at least one second gold finger structure located between the first gold finger structures. Wherein, at least one of the second gold finger structures is provided with at least one isolation groove, and the second gold finger structure includes a plurality of conductive segments located on both sides of the isolation groove along the first direction; at least one of the first gold finger structures is continuously arranged along the first direction; The first direction, the second direction, and the thickness direction of the substrate layer intersect each other in pairs.

[0005] In some embodiments, the end of the flexible circuit board along the first direction includes a bent section and fixed sections located on opposite sides of the bent section along the first direction, wherein the isolation groove is located within the bent section; Preferably, at both ends of the conductive layer along the first direction, the two first gold finger structures are continuously disposed along the first direction; Preferably, the first gold finger structure is an integral continuous copper foil, which is bonded to the surface of the substrate layer; Preferably, at least one end of the conductive layer along the first direction, each of the second gold finger structures includes a plurality of the conductive segments; Preferably, each of the conductive segments is a copper foil segment, and the copper foil segment is bonded to the surface of the substrate layer; Preferably, at at least one end of the conductive layer along the first direction, the number of conductive segments in each of the second gold finger structures is the same.

[0006] In some embodiments, the isolation trench penetrates the conductive layer along the thickness direction of the substrate layer, or the depth of the isolation trench is less than the thickness of the conductive layer; Preferably, along the second direction, the isolation groove includes a plurality of sub-isolation grooves arranged at intervals; Preferably, along the second direction, at least one side of the isolation groove extends to the edge of the second gold finger structure; Preferably, along the second direction, the width of the isolation groove is less than or equal to 80% of the width of the second gold finger structure; Preferably, along the second direction, the width of the isolation groove is greater than or equal to 50% of the width of the second gold finger structure; Preferably, along the second direction, both sides of the isolation groove extend to the edge of the second gold finger structure, and adjacent conductive segments are isolated from each other along the first direction; Preferably, in each of the second gold finger structures, the lengths of the isolation grooves along the first direction are all equal.

[0007] In some embodiments, the length of the isolation groove along the first direction is 0.08 mm to 0.4 mm; Preferably, the length of the isolation groove along the first direction is 0.1mm to 0.3mm.

[0008] In some embodiments, along the first direction, the length of the gold finger structure is L, and the number of conductive segments is N, where 0.5mm ≤ L / N; Preferably, 0.5mm ≤ L / N ≤ 2mm; Preferably, 0.5mm ≤ L / N ≤ 1.5mm; Preferably, 1.0mm ≤ L < 2.5mm, N = 2 or 3; Preferably, 2.5mm ≤ L < 4mm, N = 3 or 4; Preferably, 4.0mm≤L, N≥4; Preferably, 4.0mm≤L, N=4.

[0009] In some embodiments, the edges of the conductive segments that are close to each other are rounded. Preferably, the radius of the rounded corner is 0.05mm to 0.2mm; Preferably, the radius of the rounded corner is 0.05mm to 0.1mm.

[0010] In some embodiments, the flexible circuit board further includes a filler layer disposed within the isolation groove; Preferably, the filler layer comprises an insulating material; Preferably, the filling layer comprises an inorganic non-metallic material or an organic insulating material; Preferably, the filler layer comprises one or more of the following: a solder resist ink layer and / or a polyimide layer.

[0011] In some embodiments, the substrate layer includes a circuit layer and insulating layers disposed on opposite sides of the circuit layer, and the conductive layer is disposed on the side of one of the insulating layers opposite to the circuit layer; each of the gold finger structures is electrically connected to the circuit layer. Preferably, at least one of the conductive segments is electrically connected to the circuit layer; Preferably, each of the conductive segments is electrically connected to the circuit layer.

[0012] Another object of this application is to provide a display module comprising: A display panel having a display area and a non-display area, the non-display area including a bonding area having multiple bonding pads; and As described in the above embodiments, the gold fingers of the flexible circuit board are connected to the bonding pads.

[0013] In some embodiments, the display module further includes a conductive adhesive layer disposed between the bonding pads and each of the gold finger structures.

[0014] Another objective of this application is to provide a display device that includes a display module as described in the above embodiments or a flexible circuit board as described in the above embodiments.

[0015] The flexible circuit board and display module provided in this application have the following advantages: The flexible circuit board provided in this application embodiment has a gold finger structure at at least one end of the conductive layer along a first direction, including first gold finger structures located on both outermost sides along a second direction, and at least one second gold finger structure located between the first gold finger structures. The at least one first gold finger structure is continuously arranged along the first direction, allowing at least one side of the end of the flexible circuit board to maintain a certain degree of flexibility, facilitating the shape maintenance of the edge of the end of the flexible circuit board, and thus facilitating electrical connection between the flexible circuit board and the component to be connected by an operator. At least one second gold finger structure has an isolation groove, where the thickness of the second gold finger structure can be substantially reduced, and the remaining portion of the second gold finger structure along the second direction can be substantially reduced. This enhances the flexibility of the second gold finger structure, allowing the middle region of the end of the flexible circuit board to release stress in segments, improving or even preventing the second gold finger structure from breaking or peeling off from the surface of the substrate layer. Overall, this flexible circuit board combines the advantages of being less prone to breakage and peeling, and maintaining a certain shape for ease of use. It eliminates the need for a reinforcing layer, does not affect bonding accuracy, reduces the manufacturing cost of the flexible circuit board, simplifies the manufacturing process, and makes the flexible circuit board thinner and lighter with a wider range of applications. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a flexible circuit board provided in one embodiment of this application; Figure 2 yes Figure 1 The enlarged view of the flexible circuit board shown clearly illustrates the first and second gold finger structures. Figure 3 yes Figure 1 A cross-sectional view along the SS line, wherein the isolation groove is a groove that does not penetrate in the thickness direction; Figure 4 yes Figure 1 Another cross-sectional view along the SS line, where the isolation groove is a groove that runs through the thickness direction; Figure 5 yes Figure 1 Another cross-sectional view of the SS line, in which each conductive segment is connected to the circuit layer; Figure 6 yes Figure 1 Another cross-sectional view of the SS line in the middle, in which part of the conductive segment is connected to the circuit layer; Figure 7 yes Figure 1 A schematic diagram of a second gold finger structure in a flexible circuit board is shown. Figure 8 yes Figure 1 Another schematic diagram of the second gold finger structure in the flexible circuit board shown; Figure 9 yes Figure 1 The diagram shows a deformable structure of a flexible circuit board, wherein the isolation groove includes multiple sub-grooves; Figure 10 This is a schematic diagram of the structure of a flexible circuit board provided in another embodiment of this application; Figure 11 yes Figure 10 The enlarged view of the flexible circuit board shown clearly illustrates the first and second gold finger structures. Figure 12 yes Figure 10 A schematic diagram of a second gold finger structure in a flexible circuit board is shown. Figure 13 yes Figure 10 Another schematic diagram of the second gold finger structure in the flexible circuit board shown; Figure 14 This is a schematic diagram of the structure of a flexible circuit board provided in another embodiment of this application; Figure 15 yes Figure 14 The enlarged view of the flexible circuit board shown clearly illustrates the first and second gold finger structures. Figure 16 yes Figure 14 A schematic diagram of a second gold finger structure in a flexible circuit board is shown. Figure 17 yes Figure 14 Another schematic diagram of the second gold finger structure in the flexible circuit board shown; Figure 18 This is a cross-sectional view of the flexible circuit board in the second gold finger structure according to another embodiment of this application; Figure 19 This is a schematic diagram of the second gold finger structure of a flexible circuit board provided in another embodiment of this application; Figure 20 This is a schematic diagram of the structure of the display module provided in the embodiment of this application; Figure 21 This is a schematic diagram of the structure of the display panel in the display module provided in the embodiments of this application; Figure 22 This is a cross-sectional structural diagram of a display module provided in an embodiment of this application; Figure 23This is a cross-sectional structural diagram of a display module provided in an embodiment of this application; Figure 24 This is a cross-sectional structural diagram of a display module provided in an embodiment of this application.

[0018] The attached figures are labeled as follows: 300 - Display Module; 200-Display panel, 91-Display area, 92-Non-display area, 93-Bending area, 94-Bonding area, 940-Bonding pads, 95-Conductive adhesive layer; 100 - Flexible circuit board; 40 - Substrate layer, 41 - Circuit layer, 42 - Insulating layer, 43 - Through hole, 44 - Conductive structure; 50 - Conductive layer, 53 - Gold finger structure, 51 - First gold finger structure; 52-Second gold finger structure, 520-Isolation groove, 5201-Sub-isolation groove, 521-Closed hole, 522-Notch, 523-Through groove; 525 - Conductive segment; 526 - Rounded corners; 60 - Filler layer; X - First direction, Y - Second direction, Z - Third direction. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0021] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. It should be noted that, unless otherwise specified, different features in the embodiments of this application can be combined with each other.

[0022] For ease of understanding, the accompanying drawings show mutually orthogonal first directions X, second directions Y, and third directions Z. The Z direction is the normal direction relative to the plane encompassing the X and Y directions. Furthermore, the view of various elements parallel to the plane encompassing the X and Y directions is called a top view. Alternatively, the plane defined by the first direction X and the second direction Y is a plane parallel to the display surface of the display panel, and the third direction Z is a direction parallel to the thickness direction of the display panel.

[0023] For certain elements, the terms "above" or "above" are sometimes used when describing the position of an element located in a third direction (Z), while "below" or "below" are used when describing a position in the opposite direction. Furthermore, when using terms such as "above," "above," "below," "below," and "relative" to define the positional relationship between two elements, this includes not only the state where the two elements are directly adjacent, but also the state where the two elements are separated by gaps or other elements. Additionally, the terms "first," "second," and "third," etc., are used only for distinguishing descriptions and should not be interpreted as indicating or implying relative importance.

[0024] Currently, the mainstream structures proposed in the industry for flexible circuit boards mainly include two types: integrated continuous gold finger structures and reinforced structures with a PI (polyimide) reinforcement layer on the back. Traditional integrated continuous gold finger structures suffer from significant stress concentration during bending, and are prone to peeling, delamination, detachment, and even breakage after long-term bending, resulting in poor reliability. Conventional PI reinforcement solutions have many drawbacks. Not only are the processing steps complex and production costs high, but the production process is also prone to defects such as bonding misalignment, excess adhesive, and board surface protrusions. Furthermore, the reinforcement structure affects the bonding accuracy of the gold fingers, easily causing problems such as false pressure, poor contact, and abnormal conductivity. In addition, the overall structure is thick, making it difficult to adapt to the trend of thinner and smaller electronic products.

[0025] like Figure 1 , Figure 10 and Figure 14 As shown, this application first provides a flexible circuit board 100. As... Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 18 As shown, the flexible circuit board 100 includes a substrate layer 40 and a conductive layer 50, with the conductive layer 50 disposed on one side surface of the substrate layer 40. Figure 1 , Figure 10 and Figure 14 As shown, the conductive layer 50 has at least one end along the first direction X with a plurality of gold finger structures 53, and the plurality of gold finger structures 53 are arranged at intervals along the second direction Y. Figure 1 , Figure 10 and Figure 14As shown, at at least one end of the conductive layer 50 along the first direction X, the plurality of gold finger structures 53 include first gold finger structures 51 located on both outermost sides along the second direction Y, and at least one second gold finger structure 52 located between the first gold finger structures 51. The first direction X, the second direction Y, and the thickness direction (i.e., the third direction Z) of the substrate layer 40 intersect each other pairwise. Optionally, the first direction X is perpendicular to the third direction Z, the second direction Y is perpendicular to the third direction Z, and the first direction X intersects the second direction Y. Further optionally, the first direction X is perpendicular to the second direction Y.

[0026] In this application, such as Figure 1 , Figure 10 and Figure 14 As shown, at least one second gold finger structure 52 is provided with at least one isolation groove 520. For example... Figure 2 , Figure 11 and Figure 15 As shown, the second gold finger structure 52 includes a plurality of conductive segments 525 located on both sides of the isolation groove 520 along the first direction X. Figure 2 , Figure 11 and Figure 15 As shown, at least one first gold finger structure 51 is continuously arranged along the first direction X.

[0027] The end of the flexible circuit board 100 along the first direction X is used for connection with other components. That is, the flexible circuit board 100 uses the gold finger structure 53 at one end along the first direction X for connection with other components, such as, but not limited to, crimping and plug-in connections. The term "end" of the flexible circuit board 100 as used below refers to the end of the flexible circuit board 100 along the first direction X. In practical applications, the end of the flexible circuit board 100 undergoes bending, twisting, and reciprocating deformation. Compared to the edge region of the end, the middle region of the end is the region with the most severe bending and the highest stress concentration.

[0028] Along the first direction, the end of the flexible circuit board 100 includes a bent section and fixed sections located on both sides of the bent section. An isolation groove 520 is located within the bent section. When the end of the flexible circuit board 100 is bent, due to the isolation groove 520, the position on the flexible circuit board 100 corresponding to the isolation groove 520 can undergo significant deformation. This allows the portions of the second gold finger structure 52 located on opposite sides of the isolation groove 520 to undergo adaptive deformation, preventing problems such as breakage or peeling of the second gold finger structure 52.

[0029] In this embodiment, at least one first gold finger structure 51 is continuously arranged along the first direction X, so that at least one edge of the end of the flexible circuit board 100 maintains a certain degree of toughness, which facilitates the edge of the end of the flexible circuit board 100 to maintain its shape, thereby facilitating the operator to electrically connect it to the component to be connected. Furthermore, since the bending of the first gold finger structure 51 is relatively small, the first gold finger structure 51 has a large contact area with the substrate layer 40, which can resist bending deformation and prevent warping and peeling. At least one second gold finger structure 52 is provided with an isolation groove 520, such as... Figure 3 and Figure 4 As shown, at the isolation groove 520, the thickness T of the second gold finger structure 52 can be substantially reduced. For example... Figure 2 , Figure 9 and Figure 11 As shown, the remaining portion of the second gold finger structure 52 along the second direction Y can be substantially reduced. Therefore, this improves the flexibility of the second gold finger structure 52, allowing stress to be released segmentally in the middle region of the end of the flexible circuit board 100, thus improving or even preventing the second gold finger structure 52 from breaking or peeling off from the surface of the substrate layer 40. Overall, the flexible circuit board 100 combines the advantages of being less prone to breakage and peeling while maintaining a certain shape for ease of use. It eliminates the need for a reinforcing layer, avoiding impact on bonding accuracy, reducing the manufacturing cost of the flexible circuit board 100, simplifying its manufacturing process, and making it thinner and lighter with a wider range of applications.

[0030] like Figure 1 , Figure 10 and Figure 14 As shown, in some embodiments of this application, the flexible circuit board 100 is provided with a first gold finger structure 51 and a second gold finger structure 52 at both ends.

[0031] In some embodiments of this application, such as Figure 1 , Figure 10 and Figure 14 As shown, at either end of the flexible circuit board 100, two first gold finger structures 51 are continuously arranged along the first direction X.

[0032] In some alternative embodiments, such as Figure 1 , Figure 10 and Figure 14 As shown, at any end of the flexible circuit board 100, each second gold finger structure 52 includes a plurality of conductive segments 525.

[0033] In some embodiments, the first gold finger structure 51 is a one-piece continuous copper foil that is bonded to the surface of the substrate layer 40. The multiple conductive segments 525 of the second gold finger structure 52 are multiple copper foil segments, each of which is bonded to the surface of the substrate layer 40.

[0034] In some other embodiments, at either end of the flexible circuit board 100, when the number of gold finger structures 53 is relatively large, and the overall width D of the flexible circuit board 100 along the second direction Y (e.g., Figure 1 When the area shown is relatively large, at least one of the second gold finger structures 52 can be arranged continuously along the second direction Y. For example, one or two second gold finger structures 52 located in the middle region can be arranged continuously along the second direction Y.

[0035] In some embodiments, such as Figure 4 and Figure 5 As shown, the substrate layer 40 includes a circuit layer 41 and insulating layers 42 disposed on opposite sides of the circuit layer 41. A conductive layer 50 is disposed on the surface of one of the insulating layers 42 facing away from the circuit layer 41. A gold finger structure 53 is electrically connected to the circuit layer 41. Figure 5 and Figure 6 As shown, the insulating layer 42 has a through hole 43 extending in the third direction Z, and the gold finger structure 53 is connected to the circuit layer 41 through the through hole 43. A conductive structure 44 may be provided inside the through hole 43. The conductive structure 44 may be a ring-shaped conductive structure formed on the inner wall of the through hole 43 by chemical copper plating, electroplating, or other methods, or a conductive columnar structure pre-embedded in the through hole 43.

[0036] In some alternative embodiments, such as Figure 5 As shown, in the second gold finger structure 52, at least one conductive segment 525 may be connected to the circuit layer 41 via a via 43. Alternatively, in some optional embodiments, such as Figure 5 As shown, each conductive segment 525 is connected to the circuit layer 41 via a via 43.

[0037] In some embodiments of this application, such as Figure 3 , Figure 4 As shown, in the third direction Z, the depth t of the isolation trench 520 is less than or equal to the thickness T of the conductive layer 50. Figure 3 As shown, when the depth t of the isolation groove 520 is less than the thickness T of the conductive layer 50, the two conductive segments 525 can maintain a substantial connection and electrical connection through the bottom portion of the isolation groove 520. Since the bottom portion of the isolation groove 520 is relatively thin, it easily adapts and deforms during bending with the flexible circuit board 100, making it less prone to breakage and peeling. In some optional embodiments, t / T ≥ 50%. Further optionally, t / T ≥ 60%. Further optionally, t / T ≥ 70%. The purpose of this configuration is to minimize the thickness of the second gold finger structure 52, thereby improving the overall flexibility of the second gold finger structure 52 and reducing the mutual influence between adjacent conductive segments 525.

[0038] In some alternative embodiments, such as Figure 4 , Figure 5 , Figure 6 and Figure 18 As shown, the depth t of the isolation groove 520 is equal to the thickness T of the conductive layer 50. At this time, the isolation groove 520 is a groove that penetrates the conductive layer 50 along the third direction Z.

[0039] In some alternative embodiments, such as Figure 9 and Figure 13 As shown, the isolation groove 520 includes a plurality of sub-isolation grooves 5201 spaced apart along the second direction Y. The plurality of sub-isolation grooves 5201 together remove a portion of the second gold finger structure 52 along the second direction Y.

[0040] In some embodiments of this application, along the second direction Y, the isolation groove 520 may be configured to extend to at least one edge of the second gold finger structure 52, or it may be configured to be spaced apart from the two edges of the second gold finger structure 52.

[0041] like Figure 1 and Figure 2 As shown, in some embodiments of this application, along the second direction Y, the edge of the isolation groove 520 is spaced apart from the two edges of the second gold finger structure 52. That is, in the top view, as... Figure 2 As shown, the isolation groove 520 is a closed hole 521. Adjacent conductive segments 525 are not completely disconnected in the first direction X; instead, they remain substantially connected and electrically connected. This does not change the electrical connection between each gold finger structure 53 and the component to be connected. When the flexible circuit board 100 is bent and deformed at its end, the connection points between adjacent conductive segments 525 are thinner and narrower, resulting in less mutual influence between adjacent conductive segments 525. Therefore, each conductive segment 525 can essentially adapt and deform independently.

[0042] The specific shape of the isolation groove 520 is not limited; it can be circular, rectangular, rhomboid, or other shapes, etc. The only requirement is that the second gold finger structure 52 can be partially removed along the second direction Y. For example... Figure 9 As shown, the specific shape of each sub-isolation groove 5201 is not limited; it can be circular, rectangular, rhomboid, or other shapes, etc. In some optional embodiments, such as... Figure 8 As shown, the isolation groove 520 and its sub-isolation groove 5201 are generally rectangular in shape.

[0043] In some embodiments, based on different shapes of the isolation groove 520, the length H (dimension along the first direction X) of the isolation groove 520 at different positions along the second direction Y can be the same or different. For example... Figure 2 As shown, taking the isolation groove 520 as a rectangular groove as an example, the length H of the isolation groove 520 at different positions along the second direction Y is equal.

[0044] In some embodiments of this application, the length H of the isolation groove 520 along the first direction X is greater than 0 and does not exceed 0.4 mm. This is to ensure that the length H of the isolation groove 520 along the first direction X is not too large, thus avoiding excessive removal of the second gold finger structure 52 and affecting its effective usable area. This ensures sufficient contact area between the second gold finger structure 52 and the component to be connected, guaranteeing a stable connection. Furthermore, the shorter length H of the isolation groove 520 along the first direction X prevents unwanted impurities from easily remaining or accumulating within the isolation groove 520, which could affect the second gold finger structure 52 itself and the electrical connection between the second gold finger structure 52 and the component to be connected.

[0045] In some alternative embodiments, the length H of the isolation groove 520 along the first direction X is 0.08 mm to 0.4 mm. The purpose of this setting is to ensure that the length H of the isolation groove 520 along the first direction X is not too small, so that the isolation groove 520 can be effectively formed.

[0046] In some alternative embodiments, the length H of the isolation groove 520 along the first direction X is 0.1 mm to 0.3 mm.

[0047] In some specific embodiments and in some optional embodiments, the length H of the isolation groove 520 along the first direction X is 0.08mm, 0.09mm, 0.1mm, 0.12mm, 0.15mm, 0.18mm, 0.20mm, 0.22mm, 0.25mm, 0.28mm, 0.30mm, 0.32mm, 0.35mm, 0.38mm, 0.40mm, etc.

[0048] The larger the length L of the second gold finger structure 52 along the first direction, the larger the length H of the isolation groove 520 along the first direction X can be set accordingly, so that the conductive segments 525 can be spaced further apart to accommodate greater deformation.

[0049] In some embodiments, the ratio of the width w (the dimension along the second direction Y) of the isolation groove 520 to the width W of the second gold finger structure 52 is w / W≥50. The purpose of this arrangement is that at least half of the second gold finger structure 52 is removed in the width direction at the isolation groove 520, and the width of the remaining portion is small, thereby significantly improving the adaptability of the second gold finger structure 52 to deformation.

[0050] In some alternative embodiments, w / W ≤ 80%. This arrangement aims to ensure that at the isolation slot 520, the second gold finger structure 52 retains at least one-fifth of its width, thus minimizing the increase in resistance between adjacent conductive segments 525 and guaranteeing effective current signal transmission. This is more advantageous for schemes where not all conductive segments 525 are electrically connected to the line layer 41.

[0051] In some specific embodiments of this application, the ratio of the width w of the isolation groove 520 to the width W of the second gold finger structure 52 can be 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, etc.

[0052] like Figure 9 As shown, in some optional embodiments, each sub-isolation groove 5201 can be a closed hole 521. In this embodiment, the width w of the isolation groove 520 refers to the sum of the widths w1 of each sub-isolation groove 5201, such as... Figure 9 As shown.

[0053] In some alternative embodiments, such as Figure 10 , Figure 11 , Figure 12 and Figure 13 As shown, along the second direction Y, at least one side of the isolation groove 520 extends to the edge of the second gold finger structure 52. In this case, the isolation groove 520 on the second gold finger structure 52 manifests as a notch 522 opened from the edge of the second gold finger structure 52. The opening directions of different isolation grooves 520 can be the same or different, such as... Figure 10 As shown. One or more openings of notches 522 may face one of the first gold finger structures 51, and the other or more openings of notches 522 may face another first gold finger structure 51.

[0054] like Figure 13 As shown, for the isolation groove 520 with a notch 522, the isolation groove 520 can also include multiple sub-isolation grooves 5201. In each isolation groove 520, at least one sub-isolation groove 5201 can be connected along the second direction Y to the edge of the second gold finger structure 52, that is, at least one sub-isolation groove 5201 is a notch 522. The other sub-isolation grooves 5201 can be notches 522 or closed holes 521, such as... Figure 13 As shown. In this embodiment, the width w of the isolation groove 520 refers to the sum of the widths w1 of each sub-isolation groove 5201, such as... Figure 9 and Figure 13 As shown.

[0055] In some embodiments, such as Figure 14As shown, along the second direction Y, both sides of the isolation groove 520 extend to the edge of the second gold finger structure 52. Thus, the isolation groove 520 is a through groove 523 that penetrates the second gold finger structure 52 along the second direction Y.

[0056] In some alternative embodiments, the isolation groove 520 penetrates the second gold finger structure 52 in the second direction Y and also penetrates the second gold finger structure 52 in the third direction Z. Thus, adjacent conductive segments 525 are isolated from each other along the first direction X. The purpose of this arrangement is that the isolation groove 520 completely divides the second gold finger structure 52 into multiple parts, allowing each conductive segment 525 to deform independently without interfering with each other when the second gold finger structure 52 is bent or deformed.

[0057] If adjacent conductive segments 525 are completely separated along the first direction X, and not all conductive segments 525 are connected to the line layer 41, other methods can be used to make adjacent conductive segments 525 electrically connected. See the following... Figure 23 and Figure 24 As shown, adjacent conductive segments 525 are electrically connected by conductive adhesive layers 95 disposed on their surfaces.

[0058] In some alternative embodiments, such as Figure 1 , Figure 10 and Figure 14 As shown, in each second gold finger structure 52, the length H of the isolation groove 520 along the first direction X is equal. The isolation groove 520 can be a rectangular through groove 523.

[0059] like Figure 8 , Figure 13 and Figure 17 As shown, the number of isolation grooves 520 on any second gold finger structure 52 can be multiple.

[0060] In some alternative embodiments, the number of conductive segments 525 is the same in each of the second gold finger structures 52. In the flexible circuit board 100, as... Figure 1 , Figure 10 and Figure 14 As shown, the length L along the first direction X of each gold finger structure 53 is close, or even equal. Figure 1 , Figure 10 and Figure 14 The length L of the first gold finger structure 51 and the length L of the second gold finger structure 52 are shown. That is, in some embodiments of this application, each second gold finger structure 52 is divided into multiple conductive segments 525 in the same way, either by spacing or partial spacing.

[0061] In the second gold finger structure 52, the number of conductive segments 525 is determined according to the length L of the second gold finger structure 52 along the first direction X. Specifically, the larger the length L of the second gold finger structure 52 along the first direction X, the more isolation grooves 520 and the more conductive segments 525 there are, so as to ensure that the length h of each conductive segment 525 along the first direction X is not too large, and that each conductive segment 525 can effectively adapt to deformation without easily breaking or peeling off.

[0062] It is understandable that, for an isolation groove 520 that penetrates the second gold finger structure 52 in the second direction Y, the length h of each conductive segment 525 along the first direction X is calculated from the edge of the conductive segment 525 along the first direction X, that is, from the edge of the isolation groove 520 along the first direction X. For an isolation groove 520 that does not penetrate the second gold finger structure 52 in the second direction Y, the length h of each conductive segment 525 along the first direction X can be calculated from the midpoint of the isolation groove 520 along the first direction X, or in other words, the length h of each conductive segment 525 along the first direction X can include a portion of the length H of the isolation groove 520 along the first direction X. Here, it is understood that, since the length H of the isolation groove 520 along the first direction X is relatively small, the midpoint of the isolation groove 520 along the first direction X is a general location.

[0063] In some embodiments of this application, the length of the second gold finger structure 52 along the first direction X is L, and the number of conductive segments 525 is N, then L / N ≤ 2mm. That is, the length h of each conductive segment 525 along the first direction X is no more than 2mm. The purpose of this setting is to ensure that the length h of each conductive segment 525 along the first direction X is not too large, and that each conductive segment 525 can effectively adapt to deformation without easily breaking or peeling off.

[0064] In some embodiments of this application, 0.5mm ≤ L / N. The purpose of this setting is to ensure that the length h of each conductive segment 525 along the first direction X is at least 0.5mm. While avoiding effective adaptive deformation of each conductive segment 525, the length h of each conductive segment 525 along the first direction X is appropriate, eliminating the need to provide too many isolation grooves 520 on the second gold finger structure 52, thereby reducing the processing and manufacturing difficulty of the second gold finger structure 52 and its isolation grooves 520.

[0065] In some alternative embodiments, 0.5mm ≤ L / N ≤ 1.5mm.

[0066] In some embodiments of this application, the length L of the second gold finger structure 52 along the first direction X is greater than or equal to 10 mm.

[0067] In some optional embodiments, when 1.0mm ≤ L < 2.5mm, N = 2. That is, two conductive segments 525 are divided on the second gold finger structure 52. The length h of each conductive segment 525 along the first direction X is: 0.5mm ≤ L < 1.25mm. Optionally, the lengths of the two conductive segments 525 are close. Optionally, the length h of each conductive segment 525 along the first direction X is: 0.8mm ≤ L < 1.7mm. Optionally, the length h of each conductive segment 525 along the first direction X is: 1mm ≤ L < 1.5mm. Optionally, the length h of each conductive segment 525 along the first direction X is: 1.1mm ≤ L < 1.4mm. Optionally, the length h of each conductive segment 525 along the first direction X is: 1.2mm ≤ L < 1.5mm.

[0068] In some optional embodiments, N=2 when 2.5mm≤L<4mm. That is, two conductive segments 525 are divided on the second gold finger structure 52. The length h of each conductive segment 525 along the first direction X is: 1.25mm≤L<2mm. Optionally, the lengths of the two conductive segments 525 are close. Optionally, the length h of each conductive segment 525 along the first direction X is: 1.4mm≤L<2mm. Optionally, the length h of each conductive segment 525 along the first direction X is: 1.5mm≤L<2mm.

[0069] In some optional embodiments, when 2.5mm ≤ L < 4mm, N = 3. That is, three conductive segments 525 are divided on the second gold finger structure 52. The length h of each conductive segment 525 along the first direction X is: 0.5mm ≤ L < 2mm. Optionally, the lengths of the three conductive segments 525 are close. Optionally, the length h of each conductive segment 525 along the first direction X is: 0.8mm ≤ L < 1.8mm. Optionally, the length h of each conductive segment 525 along the first direction X is: 1mm ≤ L < 1.8mm. Optionally, the length h of each conductive segment 525 along the first direction X is: 1mm ≤ L < 1.6mm. Optionally, the length h of each conductive segment 525 along the first direction X is: 1mm ≤ L < 1.5mm.

[0070] In some optional embodiments, when 2.5mm ≤ L < 4mm, N = 4. That is, in this case, four conductive segments 525 are divided on the second gold finger structure 52. Optionally, the length h of each conductive segment 525 along the first direction X is: 0.6mm ≤ L < 2mm. Optionally, the length h of each conductive segment 525 along the first direction X is: 0.8mm ≤ L < 2mm. Optionally, the length h of each conductive segment 525 along the first direction X is: 1mm ≤ L < 2mm. Optionally, the length h of each conductive segment 525 along the first direction X is: 0.8mm ≤ L < 2mm. Optionally, the length h of each conductive segment 525 along the first direction X is: 1mm ≤ L < 1.5mm.

[0071] In some alternative embodiments, 4.0mm ≤ L, N ≥ 4. That is, at least four conductive segments 525 are divided on the second gold finger structure 52. In some alternative embodiments, 4.0mm ≤ L, N = 4.

[0072] In some embodiments of this application, in any second gold finger structure 52, the length h of each conductive segment 525 along the first direction is equal.

[0073] In some embodiments of this application, the length h of the conductive segment 525 along the first direction is equal in multiple second gold finger structures 52.

[0074] In some embodiments of this application, such as Figure 7 , Figure 12 , Figure 13 and Figure 16 As shown, the edges of the conductive segments 525 that are close to each other are provided with rounded corners 526. This allows for a smooth transition at the corners of the conductive segments 525, which can prevent stress concentration at the corners of the isolation groove 520 during the bending of the flexible circuit board 100, especially at the inner corners of the isolation groove 520. Furthermore, it can prevent the conductive segments 525 from peeling off from the substrate layer 40.

[0075] In some alternative embodiments, the radius R of the fillet 526 is 0.05mm to 0.2mm. In some alternative embodiments, the radius R of the fillet 526 is 0.05mm to 0.1mm.

[0076] like Figure 19As shown, in some embodiments of this application, at least one second gold finger structure 52 may be provided with multiple isolation grooves 520, and the multiple isolation grooves 520 may be the same or not completely the same. For example, taking the second gold finger structure 52 as an example, one isolation groove 520 may be a through groove 523 extending through the second gold finger structure 52 along the second direction Y, another isolation groove 520 may be a notch 522 connecting to one side edge of the second gold finger structure 52 along the second direction Y, and yet another isolation groove 520 may be a closed hole 521 spaced apart from both sides of the second gold finger structure 52 along the second direction Y. These three types of isolation grooves 520 can each be provided with reference to the descriptions of the foregoing embodiments.

[0077] In some embodiments of this application, such as Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, in this flexible circuit board 100, the isolation groove 520 may not contain any filling material. That is, in this case, there is an air gap between adjacent conductive segments 525.

[0078] In some embodiments of this application, such as Figure 18 As shown, the flexible circuit board 100 also includes a filler layer 60, which is disposed within the isolation groove 520. The thickness of the filler layer 60 may be less than or equal to the depth t of the isolation groove 520.

[0079] like Figure 18 As shown, in some alternative embodiments, the thickness of the filler layer 60 is equal to the depth t of the isolation groove 520.

[0080] In some alternative embodiments, the filler layer 60 includes an insulating material.

[0081] In some alternative embodiments, the filler layer 60 comprises an inorganic non-metallic material or an organic insulating material.

[0082] In some alternative embodiments, the filler layer 60 comprises one or more of a solder resist ink layer and / or a polyimide layer.

[0083] The flexible circuit board 100 provided in this application embodiment can be applied to any situation where two components need to be electrically or communicatively connected. For example, the flexible circuit board 100 provided in this application embodiment is used in applications including but not limited to display modules 300, camera modules, fingerprint recognition modules, and button modules.

[0084] like Figure 20 , Figure 22 , Figure 23 and Figure 24As shown, this application embodiment also provides a display module 300, which includes a display panel 200 and the flexible circuit board 100 described in the above embodiments. Wherein, as Figure 21 As shown, the display panel 200 has a display area 91 and a non-display area 92, the non-display area 92 including a bonding area 94. Figure 20 As shown, one end of the flexible circuit board 100 is connected to the bonding area 94. Specifically, as... Figure 21 As shown, the bonding area 94 has multiple bonding pads 940. For example... Figure 20 , Figure 22 , Figure 23 and Figure 24 As shown, the bonding pads 940 and the gold finger structure 53 are connected in a one-to-one correspondence. Figure 20 In the diagram, the bonding pad 940 and the gold finger structure 53 (first gold finger structure 51 and second gold finger connector 52) are represented by dashed boxes. This indicates that, in the top view, the two are corresponding and both are obscured and invisible by the substrate layer 40.

[0085] like Figure 21 , Figure 22 , Figure 23 and Figure 24 As shown, in the display panel 200, the non-display area 92 also includes a bending area 93, which can be bent backward so that the bonding area 94 can be flipped to the back of the display panel 200.

[0086] like Figure 22 , Figure 23 and Figure 24 As shown, along the thickness direction of the display panel 200, the bonding pads 940 are directly or indirectly bonded to the gold finger structure 53. For example, Figure 22 As shown, in some optional embodiments, along the thickness direction of the display panel 200, the bonding pad 940 is directly bonded to the gold finger structure 53, and the two can maintain a certain pressure bond through other means. For example... Figure 23 and Figure 24 As shown, in some optional embodiments, a conductive adhesive layer 95 is provided between the bonding pad 940 and the gold finger structure 53 along the thickness direction of the display panel 200. The conductive adhesive layer 95 enables a physical and electrical connection between the bonding pad 940 and the gold finger structure 53. For example, Figure 23 As shown, the conductive adhesive layer 95 can fill the isolation groove 520. (As indicated...) Figure 24 As shown, the isolation groove 520 may be provided with the aforementioned filling layer 60.

[0087] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0088] Finally, this application also provides a display device (not shown) that includes the display module 300 described in the above embodiments, or the flexible circuit board described in the above embodiments.

[0089] The display device may include devices with image processing capabilities, such as mobile phones, desktop computers, laptops, tablets, automotive displays, wearable devices, etc. Because the display device includes the flexible circuit board described in the above embodiments of the display module 300 of this application, the performance of the display device is reliable.

[0090] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A flexible circuit board, characterized in that, include: Substrate layer; as well as A conductive layer is disposed on one side surface of the substrate layer, and the conductive layer has a plurality of gold finger structures at at least one end along a first direction; The plurality of gold finger structures are arranged at intervals along a second direction; the plurality of gold finger structures include first gold finger structures located on the outermost two sides along the second direction, and at least one second gold finger structure located between the first gold finger structures; Wherein, at least one of the second gold finger structures is provided with at least one isolation groove, and the second gold finger structure includes a plurality of conductive segments located on both sides of the isolation groove along the first direction; at least one of the first gold finger structures is continuously arranged along the first direction; The first direction, the second direction, and the thickness direction of the substrate layer intersect each other in pairs.

2. The flexible circuit board as described in claim 1, characterized in that, The flexible circuit board includes a bent section at its end along the first direction, and fixed sections located on opposite sides of the bent section along the first direction, wherein the isolation groove is located within the bent section; Preferably, at both ends of the conductive layer along the first direction, the two first gold finger structures are continuously disposed along the first direction; Preferably, the first gold finger structure is an integral continuous copper foil, which is bonded to the surface of the substrate layer; Preferably, at least one end of the conductive layer along the first direction, each of the second gold finger structures includes a plurality of the conductive segments; Preferably, each of the conductive segments is a copper foil segment, and the copper foil segment is bonded to the surface of the substrate layer; Preferably, at at least one end of the conductive layer along the first direction, the number of conductive segments in each of the second gold finger structures is the same.

3. The flexible circuit board as described in claim 1, characterized in that, Along the thickness direction of the substrate layer, the isolation groove penetrates the conductive layer, or the depth of the isolation groove is less than the thickness of the conductive layer; Preferably, along the second direction, the isolation groove includes a plurality of sub-isolation grooves arranged at intervals; Preferably, along the second direction, at least one side of the isolation groove extends to the edge of the second gold finger structure; Preferably, along the second direction, the width of the isolation groove is less than or equal to 80% of the width of the second gold finger structure; Preferably, along the second direction, the width of the isolation groove is greater than or equal to 50% of the width of the second gold finger structure; Preferably, along the second direction, both sides of the isolation groove extend to the edge of the second gold finger structure, and adjacent conductive segments are isolated from each other along the first direction; Preferably, in each of the second gold finger structures, the lengths of the isolation grooves along the first direction are all equal.

4. The flexible circuit board as described in claim 1, characterized in that, The length of the isolation groove along the first direction is 0.08mm~0.4mm; Preferably, the length of the isolation groove along the first direction is 0.1mm to 0.3mm.

5. The flexible circuit board as described in claim 1, characterized in that, Along the first direction, the length of the gold finger structure is L, and the number of conductive segments is N, where 0.5mm ≤ L / N; Preferably, 0.5mm ≤ L / N ≤ 2mm; Preferably, 0.5mm ≤ L / N ≤ 1.5mm; Preferably, 1.0mm ≤ L < 2.5mm, N = 2 or 3; Preferably, 2.5mm ≤ L < 4mm, N = 3 or 4; Preferably, 4.0mm≤L, N≥4; Preferably, 4.0mm≤L, N=4.

6. The flexible circuit board as described in claim 1, characterized in that, The conductive segments have rounded corners at their adjacent edges; Preferably, the radius of the rounded corner is 0.05mm to 0.2mm; Preferably, the radius of the rounded corner is 0.05mm to 0.1mm.

7. The flexible circuit board as described in any one of claims 1 to 6, characterized in that, The flexible circuit board further includes a filler layer, which is disposed within the isolation groove; Preferably, the filler layer comprises an insulating material; Preferably, the filling layer comprises an inorganic non-metallic material or an organic insulating material; Preferably, the filler layer comprises one or more of the following: a solder resist ink layer and / or a polyimide layer.

8. The flexible circuit board as described in any one of claims 1 to 6, characterized in that, The substrate layer includes a circuit layer and insulating layers disposed on opposite sides of the circuit layer, and the conductive layer is disposed on the side of one of the insulating layers opposite to the circuit layer; each of the gold finger structures is electrically connected to the circuit layer. Preferably, at least one of the conductive segments is electrically connected to the circuit layer; Preferably, each of the conductive segments is electrically connected to the circuit layer.

9. A display module, characterized in that, include: The display panel has a display area and a non-display area, the non-display area including a bonding area, the bonding area having a plurality of bonding pads; as well as The flexible circuit board according to any one of claims 1 to 8, wherein each of the gold finger structures of the flexible circuit board is correspondingly connected to the bonding pad.

10. The display module as described in claim 9, characterized in that, The display module also includes a conductive adhesive layer, which is disposed between the bonding pads and each of the gold finger structures.

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