Flexible circuit board, display module and display
By setting the serrated ends in the cover layer of the flexible circuit board and the gold finger structure, the short-circuit connection problem caused by the gathering of the end area of the cover layer during the compression and heat expansion process is solved, and the product yield and life are improved.
Patent Information
- Application Number
- CN202421622203.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-10
- Publication Date
- 2025-06-17
- Estimated Expiration
- 2034-07-10
AI Technical Summary
In the prior art, when ACF fitting is biased or the distance between gold fingers is narrow, it is easy to cause the gold ball to gather in the end area of the cover layer during the compression and heat expansion process, resulting in short-circuit connection, affecting product yield and life.
In the cover layer of the flexible circuit board, the zigzag ends are arranged, and the gold finger structure is arranged intersected, so that at least one convex structure is positioned in the space area between each two adjacent gold finger terminals, thereby acting as an insulating partition when the gold balls gather.
Effectively prevent short-circuit connections caused by the accumulation of gold balls in the end area of the cover layer, improve product yield, reduce the risk of gold ball short-circuit during long-term use, and extend product life.
Smart Images
Figure CN222996738U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of liquid crystal display technology, and particularly to a flexible circuit board, a display module, and a display device. Background Art
[0002] In the bonding process of panel manufacturing, ACF (Anisotropic Conductive Film) plays an important role. ACF is a material that can achieve conductive connection in a short time. Its characteristic is that it conducts electricity in the longitudinal force direction, while having high impedance characteristics in the transverse plane. Through the bursting of conductive particles (such as gold balls) inside the ACF during the hot pressing process, the circuit connection between the liquid crystal panel and the FPC (Flexible Printed Circuit) is realized, while avoiding short circuits between adjacent electrodes. The distribution and quantity of gold balls in the ACF have a direct impact on the conductive performance, and precise process control is required to achieve high conductivity and high reliability.
[0003] In the prior art, a cover layer is provided below the FPC near the bonding area, forming a step under the bonding area. When the ACF is misaligned during bonding or the pitch of the gold fingers is narrow, it is easy to cause the gold balls to gather in the end area of the cover layer during the process of outward expansion under pressure and heat. The gold balls between the two traces are prone to dense short circuits, resulting in poor functionality. At the same time, there is also a risk of short circuits during long-term use due to the too small spacing between the gold balls. Summary of the Invention
[0004] In order to solve at least one problem existing in the prior art, the purpose of this application is to provide a flexible circuit board, a display module, and a display device, which can effectively prevent short circuit connections caused by the aggregation of gold balls in the end area of the cover layer, help improve the product yield, and can also reduce the risk of gold ball short circuits during long-term use, which is beneficial to extending the product life.
[0005] To achieve the above purpose, the flexible circuit board provided by this application includes: a substrate layer, a wire layer, and a cover layer stacked in sequence; wherein,
[0006] One end of the wire layer is provided with a gold finger structure; the gold finger structure includes a plurality of gold finger terminals arranged in parallel;
[0007] The cover layer is an insulating layer and at least does not cover the gold finger structure; the cover layer includes a cover layer main body and a serrated end close to the gold finger structure, and the serrated end includes a plurality of protruding structures arranged in parallel;
[0008] Moreover, the serrated end is arranged crosswise with the gold finger structure, so that at least one protruding structure is positioned in the interval area between every two adjacent gold finger terminals.
[0009] Optionally, the protruding structure is triangular.
[0010] Further optionally, the protruding height range of the protruding structure is 0.2 mm - 0.6 mm.
[0011] Optionally, the protruding structure is an isosceles triangle; the apex angle range of the isosceles triangle is 30° - 90°.
[0012] Optionally, the gold finger terminals include a first gold finger terminal and a second gold finger terminal; wherein the first gold finger terminal is closer to the cover layer body than the second gold finger terminal.
[0013] Further optionally, the second gold finger terminal is arranged with a gap from the adjacent protruding structure; the corresponding gap width is less than 1 / 3 times the width of the spacing area.
[0014] Optionally, the first gold finger terminal is arranged with a gap from the adjacent protruding structure; the corresponding gap width is less than 1 / 4 times the width of the spacing area.
[0015] Optionally, the thickness range of the cover layer is 10 μm - 20 μm.
[0016] To achieve the above object, the present application also provides a display module, including: the flexible circuit board as described above.
[0017] To achieve the above object, the present application also provides a display, including: the display module as described above.
[0018] A flexible circuit board, a display module and a display of the present application, by providing a cover layer on the conductive layer of the flexible circuit board, setting the end of the cover layer close to the gold finger structure to be serrated, and arranging the serrated end to cross the gold finger structure, during the bonding process, after the gold balls in the ACF expand outward under pressure and heat, the protruding structures at the serrated end are between adjacent gold finger terminals, playing an insulating and separating role for the aggregated gold balls. Thus, it can effectively prevent short - circuit connection caused by the aggregation of gold balls in the end area of the cover layer, help improve the product yield, and can also reduce the risk of gold ball short - circuit during long - term use, which is beneficial to extending the product life.
[0019] Other features and advantages of the present application will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The drawings are used to provide a further understanding of the present application, and constitute a part of the specification, and together with the embodiments of the present application, are used to explain the present application, and do not constitute a limitation to the present application. In the drawings:
[0021] Figure 1 is a schematic structural diagram of a flexible circuit board in the prior art;
[0022] Figure 2 is Figure 1 a partial enlarged view of part A in
[0023] Figure 3 is a schematic laminated structure diagram of a liquid crystal module;
[0024] Figure 4 is a schematic structural diagram of a flexible circuit board according to an embodiment of the present application;
[0025] Figure 5 is Figure 4 a partial enlarged view of part B in
[0026] Figure 6 is a schematic structural diagram of a display module according to an embodiment of the present application.
[0027] Among them, the following reference numerals are specifically included:
[0028] Flexible circuit board - 100; Substrate layer - 10; Conductor layer - 20; Gold finger structure - 21; Gold finger terminal - 22; First gold finger terminal - 23; Second gold finger terminal - 24; Cover layer - 30; Cover layer main body - 31; Serrated end - 32;
[0029] ACF - 200;
[0030] Liquid crystal panel - 300;
[0031] Bonding area - 400;
[0032] Liquid crystal module - 1000. Detailed implementation manners
[0033] Embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although some embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the present application. It should be understood that the drawings and embodiments of the present application are only for exemplary purposes and are not used to limit the protection scope of the present application.
[0034] As used herein, the term "comprising" and its variations are open-ended, i.e., "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". The relevant definitions of other terms will be given in the following description.
[0035] First of all, it should be noted that in the related art, as Figures 1 to 3 shown, the flexible circuit board 100 includes a substrate layer 10, a wire layer 20, and a cover layer 30 stacked in sequence. The end of the cover layer 30 close to the gold finger structure 21 is a flush structure, forming a step under the bonding area 400. During the bonding process, the ACF 200 is applied to the bonding area 400 between the flexible circuit board 100 and the liquid crystal panel 300. During the process of the gold balls in the ACF 200 expanding outward under pressure and heat, they gather in the end area of the cover layer 30, and the gold balls between the two traces are prone to dense short circuits, resulting in poor function. Moreover, there is a risk of short circuits during long-term use due to the too small spacing between the gold balls.
[0036] Based on this, the present application provides a flexible circuit board, which can effectively prevent short-circuit connections caused by the aggregation of gold balls in the end area of the cover layer, helps to improve the product yield, and can also reduce the risk of gold ball short circuits during long-term use, which is beneficial to extending the product life.
[0037] Next, the embodiments of the present application will be described in detail with reference to the accompanying drawings.
[0038] As Figures 3 - 6 shown, the flexible circuit board 100 provided by the embodiment of the present application includes: a substrate layer 10, a wire layer 20, and a cover layer 30 stacked in sequence.
[0039] One end of the wire layer 20 is provided with a gold finger structure 21; the gold finger structure 21 includes a plurality of gold finger terminals 22 arranged in parallel.
[0040] The cover layer 30 is an insulating layer and at least does not cover the gold finger structure 21. The cover layer 30 includes a cover layer main body 31 and a serrated end 32 close to the gold finger structure 21. The serrated end 32 includes a plurality of protruding structures arranged in parallel.
[0041] Moreover, the serrated end 32 and the gold finger structure 21 are arranged in a cross manner, so that at least one protruding structure is positioned in the interval area between every two adjacent gold finger terminals 22.
[0042] It is understandable that the shape of the protruding structure in the embodiments of the present application can be a shape with a relatively narrow end and a relatively wide bottom, such as a triangle, a trapezoid, a semi-ellipse, or it can also be a rectangle, or it can be a special shape, as long as it can play an insulating and spacing role. The present application does not make specific restrictions on this.
[0043] It should be noted that the modifications of "one" and "several" mentioned in the present application are illustrative rather than restrictive. Those skilled in the art should understand that unless clearly specified otherwise in the context, it should be understood as "one or more"; "several" should be understood as two or more.
[0044] According to the flexible circuit board 100 in the embodiments of the present application, during the bonding process, the gold balls in the ACF 200 expand outward under pressure and heat. However, since the covering layer 30 is an insulating layer and its serrated end 32 is arranged in a crosswise manner with the gold finger structure 21, the protruding structure of the serrated end 32 is between adjacent gold finger terminals 22, playing an insulating and separating role for the aggregated gold balls, thereby effectively preventing short-circuit connections caused by the aggregation of gold balls in the end region of the covering layer 30, helping to improve the product yield, and also being able to reduce the risk of gold ball short circuit during long-term use, which is beneficial to extending the product life.
[0045] Preferably, the protruding structure is triangular. Optionally, the protruding structure is an isosceles triangle; the apex angle range of the isosceles triangle is 30° - 90°. With a regular protruding shape, the convenience of processing and laminating is improved.
[0046] Preferably, the protruding height range of the protruding structure is 0.2 mm - 0.6 mm, taking into account the reliability of the function, material saving, and the convenience of bonding.
[0047] In the embodiments of the present application, as Figure 5 shown, the gold finger terminals 22 include the first gold finger terminal 22 and the second gold finger terminal 22; among them, the first gold finger terminal 22 is closer to the covering layer main body 31 than the second gold finger terminal 22. In a specific example, the longer first gold finger terminal 22 is arranged in the middle section of the gold finger structure 21; the shorter second gold finger terminal 22 is arranged at both ends of the gold finger structure 21.
[0048] It should be noted that the concepts of "first" and "second" mentioned in the present application are only used to distinguish different gold finger terminals, and are not used to limit the interdependent relationship or relative importance of these gold finger terminals.
[0049] Preferably, the second gold finger terminal 24 is arranged with a gap from the adjacent protruding structure. Here, the gap arrangement means that there is a gap between the second gold finger terminal 24 and the adjacent protruding structure. The corresponding gap width is less than 1 / 3 times the width of the spacing area.
[0050] Similarly, the first gold finger terminal 23 can also be arranged with a gap from the adjacent protruding structure; the corresponding gap width is less than 1 / 4 times the width of the spacing area.
[0051] Specifically, by arranging the gold finger terminal 22 with a gap from the adjacent protruding structure, the aggregated gold balls can be evacuated through the gap to the area between the gold finger terminal 22 and the cover layer main body 31, thereby further preventing the short circuit connection caused by the aggregation of gold balls. By matching the corresponding gap widths for gold finger terminals 22 of different lengths, the reliability of the function and the rationality of the arrangement of the serrated protruding structures can be taken into account.
[0052] In the embodiment of the present application, the thickness range of the cover layer 30 is preferably 10 μm - 20 μm, so as to take into account the covering functionality, the end gold ball blocking functionality and the material cost. In a specific example, the material of the cover layer 30 is polyimide.
[0053] Figure 6 It is a schematic structural diagram of a display module according to an embodiment of the present application. Refer to Figure 6 As shown, the display module 1000 includes the flexible circuit board 100 and the display panel 300 in the above embodiment.
[0054] It should be noted that the explanations of the flexible circuit board in the above embodiments are also applicable to the display module in the above embodiments, and will not be elaborated here.
[0055] The present application also provides a display, including the display module in the above embodiment.
[0056] In the description of the present application, it should be noted that the relationship between the structures should be understood in a broad sense. The orientation or positional relationship indicated by terms such as "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.
[0057] Moreover, in the drawings, for clarity, the dimensions of layers, regions, components and their relative dimensions may be exaggerated. Wherein the same or similar reference numerals throughout represent the same or similar components or components with the same or similar functions.
[0058] It should be pointed out that the specific values mentioned above are only for exemplarily illustrating the implementation of the present application in detail, and should not be construed as a limitation to the present application. In other embodiments or examples, other values can be selected according to the present application, and no specific limitation is made here.
[0059] Those of ordinary skill in the art can understand that the above are only preferred embodiments of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.
Claims
1. A flexible circuit board, characterized in that: include: A substrate layer, a conductor layer and a covering layer are stacked in sequence; wherein, A gold finger structure is provided at one end of the conductor layer; the gold finger structure comprises a plurality of gold finger terminals arranged in parallel; The covering layer is an insulating layer, at least not covering the gold finger structure; the covering layer comprises a covering layer body and a sawtooth end portion close to the gold finger structure, and the sawtooth end portion comprises a plurality of protruding structures arranged in parallel; Furthermore, the sawtooth end portion and the gold finger structure are arranged crosswise, so that at least one protruding structure is positioned in the interval area between every two adjacent gold finger terminals.
2. The flexible circuit board according to claim 1, characterized in that: The protruding structure is triangular in shape.
3. The flexible circuit board according to claim 2, characterized in that: The protruding height of the protruding structure ranges from 0.2 mm to 0.6 mm.
4. The flexible circuit board according to claim 2, characterized in that: The protruding structure is an isosceles triangle; the vertex angle of the isosceles triangle ranges from 30° to 90°.
5. The flexible circuit board according to claim 1, characterized in that: The gold finger terminal includes a first gold finger terminal and a second gold finger terminal; wherein the first gold finger terminal is closer to the covering layer body than the second gold finger terminal.
6. The flexible circuit board according to claim 5, characterized in that: The second gold finger terminal is provided with a gap from the adjacent protruding structure; the corresponding gap width is less than 1 / 3 of the width of the spacing area.
7. The flexible circuit board according to claim 5, characterized in that: The first gold finger terminal is provided with a gap from the adjacent protruding structure; the corresponding gap width is less than 1 / 4 times the width of the spacing area.
8. The flexible circuit board according to claim 1, characterized in that: The thickness of the covering layer is in the range of 10 μm to 20 μm.
9. A display module, characterized in that: Comprising the flexible circuit board as claimed in any one of claims 1 to 8.
10. A display, characterized in that: Comprising the display module as claimed in claim 9.