Flexible printed circuit and display apparatus

Abstract

A flexible printed circuit and a display apparatus. The flexible printed circuit comprises: a component area configured to be connected to a plurality of components; a connection area containing a plurality of wires, the wires being configured to connect the components to an external apparatus and, in the direction perpendicular to the flexible printed circuit, the thickness of the component area being greater than the thickness of the connection area; and a transition area configured to connect the connection area and the component area, wherein a reinforcement part is provided in the transition area, and the reinforcement part is configured to reinforce the strength of the flexible printed circuit.

Description

Flexible circuit boards and display devices

[0001] This application claims priority to Chinese patent application No. 202411708644.6, filed on November 26, 2024, entitled "Flexible Circuit Board and Display Device", the contents of which are to be construed as incorporated herein by reference. Technical Field

[0002] This article relates to, but is not limited to, display technology, particularly a flexible circuit board and display device. Background Technology

[0003] Organic light-emitting diodes (OLEDs) are active-matrix display devices with advantages such as self-illumination, wide viewing angle, high contrast, low power consumption, and extremely fast response speed. With the continuous development of display technology, display devices using OLEDs as light-emitting elements and controlled by thin-film transistors (TFTs) have become the mainstream products in the display field. Summary of the Invention

[0004] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of the claims.

[0005] On one hand, this disclosure provides a flexible circuit board, including: a component area configured to connect with multiple components; a connection area including multiple traces configured to connect the components to an external device; in a direction perpendicular to the flexible circuit board, the thickness of the component area is greater than the thickness of the connection area; a transition area configured to connect the connection area and the component area; wherein, a reinforcing portion is provided in the transition area, the reinforcing portion being configured to strengthen the flexible circuit board.

[0006] In one exemplary embodiment, in a direction perpendicular to the flexible circuit board, the connection area, the component area, and the transition area each include at least two conductive layers; the thickness of the component area is greater than the thickness of the connection area, meaning that the number of conductive layers in the connection area is less than the number of conductive layers in the component area.

[0007] In one exemplary embodiment, in a direction perpendicular to the flexible circuit board, the component area includes a first conductive layer, a first substrate layer, a second conductive layer, a second substrate layer, and a third conductive layer stacked sequentially, and the connection area includes the first conductive layer and the second conductive layer.

[0008] In one exemplary embodiment, in a direction perpendicular to the flexible circuit board, the transition region includes the first conductive layer, the first substrate layer, the second conductive layer, and the second substrate layer, and the reinforcing portion is located in the second substrate layer.

[0009] In one exemplary embodiment, in a direction perpendicular to the flexible circuit board, the transition region includes a first conductive layer, a first substrate layer, a second conductive layer, a second substrate layer, and a third conductive layer; the reinforcing portion is located on the third conductive layer, or the reinforcing portion is located on the third conductive layer and the second substrate layer.

[0010] In one exemplary embodiment, the reinforcing portion includes a plurality of first sub-reinforcing portions, wherein the size of the first sub-reinforcing portions gradually increases along the direction from the component region to the connection region, and the number of the first sub-reinforcing portions gradually increases.

[0011] In one exemplary embodiment, the reinforcing portion includes a plurality of first sub-reinforcing portions, wherein the size of the first sub-reinforcing portions gradually decreases along the direction from the component region to the connection region, and the number of the first sub-reinforcing portions gradually decreases.

[0012] In one exemplary embodiment, the reinforcing portion includes a plurality of second sub-reinforcing portions penetrating the transition region. The plurality of second sub-reinforcing portions are arranged sequentially along the extension direction of the transition region, and the size of the second sub-reinforcing portions gradually decreases along the arrangement direction in the direction from the component region to the connection region.

[0013] In one exemplary embodiment, when the reinforcing portion is located between the third conductive layer and the second substrate layer, the thickness of the transition region decreases in a stepped manner along the direction from the component region to the connection region.

[0014] In one exemplary embodiment, at least two second sub-reinforcing portions are in contact with each other at one end near the component region along the arrangement direction; or, a plurality of second sub-reinforcing portions are spaced apart from each other along the arrangement direction.

[0015] In one exemplary embodiment, along the arrangement direction, the side of the plurality of second sub-reinforcement portions near the component region is an integral structure.

[0016] In one exemplary embodiment, a portion of the integral structure of the plurality of second sub-reinforcing portions is located in the second substrate layer and the third conductive layer, and the remaining portion of the plurality of second sub-reinforcing portions is located in the second substrate layer.

[0017] In one exemplary embodiment, the flexible circuit board extends along a first direction, the component area is located on one side of the connection area in a second direction, and the first direction and the second direction intersect; along the second direction, the size of the transition area is greater than or equal to 2.5 mm and less than or equal to 4.5 mm.

[0018] In one exemplary embodiment, along the first direction, the dimensions of the transition region and the connection region are smaller than the dimensions of the component region.

[0019] On the other hand, embodiments of this disclosure provide a display device, including a display substrate and a flexible circuit board as described above.

[0020] The flexible circuit board provided in this disclosure strengthens its strength by providing a transition area between the connection area and the component area, and by incorporating reinforcing portions within this transition area. This reduces stress concentration at the junction of the connection and component areas, improves deformation resistance, helps prevent trace breakage near the junction, and extends the lifespan of the flexible circuit board. When the flexible circuit board of this disclosure is applied to a display device, display anomalies caused by trace breakage on the flexible circuit board can be avoided, improving display stability and extending the lifespan of the display device.

[0021] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application can be realized and obtained by means of the solutions described in the description and the accompanying drawings.

[0022] After reading and understanding the accompanying diagrams and detailed descriptions, the other aspects can be understood.

[0023] Overview of the attached figures

[0024] The accompanying drawings are used to provide an understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0025] Figure 1 is a schematic diagram of a display device;

[0026] Figure 2 is a schematic diagram of the planar structure of a display device;

[0027] Figure 3 is a schematic diagram of the planar structure of the display area in a display substrate;

[0028] Figure 4 is a cross-sectional view of the flexible circuit board in Figure 2 along the AA direction in an exemplary embodiment;

[0029] Figure 5 is a top view of the flexible circuit board of Figure 2 in the dashed area B of an exemplary embodiment;

[0030] Figure 6 is a cross-sectional view of Figure 5 along the CC direction in an exemplary embodiment;

[0031] Figure 7 is a top view of the flexible circuit board of Figure 2 in the dashed area B in another exemplary embodiment;

[0032] Figure 8 is a cross-sectional view of Figure 7 along the CC direction in an exemplary embodiment;

[0033] Figure 9 is a top view of the flexible circuit board of Figure 2 in the dashed area B in another exemplary embodiment;

[0034] Figure 10 is a cross-sectional view of Figure 9 along the CC direction in an exemplary embodiment;

[0035] Figure 11 is a top view of the flexible circuit board of Figure 2 in the dashed area B in another exemplary embodiment;

[0036] Figure 12 is a cross-sectional view of Figure 11 along the CC direction in an exemplary embodiment;

[0037] Figure 13 is a cross-sectional view of Figure 11 along the CC direction in yet another exemplary embodiment.

[0038] Detailed Explanation

[0039] This disclosure describes several embodiments, but these descriptions are exemplary and not limiting, and it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with, or may replace, any feature or element of any other embodiment.

[0040] This disclosure includes and contemplates combinations of features and elements known to those skilled in the art. The embodiments, features, and elements disclosed in this disclosure may also be combined with any conventional features or elements to form a unique inventive scheme as defined by the claims. Any feature or element of any embodiment may also be combined with features or elements from other inventive schemes to form another unique inventive scheme as defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in this disclosure may be implemented individually or in any suitable combination. Therefore, the embodiments are not limited except by the limitations imposed by the appended claims and their equivalents. Furthermore, various modifications and changes may be made within the scope of the appended claims.

[0041] Furthermore, in describing representative embodiments, the specification may have presented methods and / or processes as a specific sequence of steps. However, the method or process should not be limited to the specific order of steps described herein, to the extent that the method or process does not depend on the specific order of steps described herein. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation of the claims. Moreover, the claims relating to the method and / or process should not be limited to the steps performed in the order written, and those skilled in the art will readily understand that these orders can be varied and still remain within the spirit and scope of the embodiments disclosed herein.

[0042] In the accompanying drawings, the size of one or more constituent elements, the thickness of layers, or areas are sometimes exaggerated for clarity. Therefore, this disclosure is not necessarily limited to these dimensions, and the shape and size of one or more parts in the drawings do not reflect true proportions. Furthermore, the drawings schematically illustrate ideal examples, and this disclosure is not limited to the shapes or values ​​shown in the drawings.

[0043] The ordinal numbers such as "first," "second," and "third" used in this specification are used to avoid confusion among the constituent elements, not to limit the quantity. The term "multiple" in this disclosure refers to two or more quantities.

[0044] In this specification, for convenience, terms such as "middle," "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer" are used to indicate orientation or positional relationships in conjunction with the accompanying drawings. This is solely for the purpose of facilitating the description and simplification, and does not imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this disclosure. The positional relationships of the constituent elements may be appropriately varied depending on the orientation of the constituent elements being described. Therefore, the use of terms not limited to those described in the specification may be appropriately replaced as needed.

[0045] In this specification, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they may refer to a fixed connection, a detachable connection, or an integral connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection via an intermediate component, or a connection within two components. Those skilled in the art will understand the meaning of these terms in this disclosure as appropriate.

[0046] In this specification, "electrical connection" includes the situation where components are connected together by elements that have a certain electrical function. There are no particular limitations on what constitutes an "electrical function," as long as it allows for the transmission of electrical signals between the connected components. Examples of "electrical functions" include not only electrodes and wiring, but also switching elements such as transistors, resistors, inductors, capacitors, and other elements with various functions.

[0047] In this specification, "parallel" refers to the state where the angle formed by two straight lines is greater than or equal to -10° and less than 10°, and therefore also includes the state where the angle is greater than or equal to -5° and less than 5°. Similarly, "perpendicular" refers to the state where the angle formed by two straight lines is greater than or equal to 80° and less than 100°, and therefore also includes the state where the angle is greater than or equal to 85° and less than 95°.

[0048] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0049] Figure 1 is a schematic diagram of a display device. As shown in Figure 1, the display device may include a timing controller, a data driver, a scan driver, a light-emitting driver, and a pixel array. The timing controller is connected to the data driver, the scan driver, and the light-emitting driver. The data driver is connected to multiple data signal lines (D1 to Dn), the scan driver is connected to multiple scan signal lines (S1 to Sm), and the light-emitting driver is connected to multiple light-emitting signal lines (E1 to Eo). The pixel array may include multiple sub-pixels Pxij, where i and j can be natural numbers. At least one sub-pixel Pxij may include a circuit unit and a light-emitting element connected to the circuit unit. The circuit unit may include at least a pixel driving circuit, which is connected to the scan signal lines, the data signal lines, and the light-emitting signal lines. In an exemplary embodiment, the timing controller can provide grayscale values ​​and control signals of specifications suitable for the data driver to the data driver, provide clock signals, scan start signals, etc. of specifications suitable for the scan driver to the scan driver, and provide clock signals, transmit stop signals, etc. of specifications suitable for the light-emitting driver to the light-emitting driver. The data driver can use grayscale values ​​and control signals received from the timing controller to generate data voltages to be provided to data signal lines D1, D2, D3, ..., Dn. For example, the data driver can sample grayscale values ​​using a clock signal and apply data voltages corresponding to the grayscale values ​​to data signal lines D1 to Dn in pixel rows, where n can be a natural number. The scan driver can generate scan signals to be provided to scan signal lines S1, S2, S3, ..., Sm by receiving clock signals, scan start signals, etc., from the timing controller. For example, the scan driver can sequentially provide scan signals with on-level pulses to scan signal lines S1 to Sm. For example, the scan driver can be configured as a shift register and can generate scan signals by sequentially transmitting scan start signals in the form of on-level pulses to the next stage circuit under the control of a clock signal, where m can be a natural number. The light-emitting driver can generate transmit signals to be provided to light-emitting signal lines E1, E2, E3, ..., Eo by receiving clock signals, transmit stop signals, etc., from the timing controller. For example, an LED driver can sequentially provide transmit signals with cutoff level pulses to LED signal lines E1 to Eo. For example, the LED driver can be configured as a shift register and can generate transmit signals by sequentially transmitting transmit stop signals in the form of cutoff level pulses to the next stage circuit under the control of a clock signal, where o can be a natural number.

[0050] Figure 2 is a schematic diagram of a planar structure of a display device. As shown in Figure 2, the display device may include a display substrate 11 and a flexible circuit board 12 bonded to the display substrate 11. The display substrate 11 may include a display area AA and a peripheral area PA surrounding the display area AA. A plurality of bonding pads 111 may be provided on one side of the peripheral area PA in the second direction Y. The plurality of bonding pads 111 may be arranged along the first direction X. The flexible circuit board 12 may be bonded to the display substrate 11 through the corresponding bonding pads 111. The first direction X and the second direction Y may intersect each other, for example, the first direction X and the second direction Y may be perpendicular to each other. The flexible circuit board 12 may include a connection area 121 and a component area 122. The component area 122 may house multiple components, such as integrated circuits (ICs), flash memory, resistors, and capacitors. The component area 122 may be configured to connect to the display substrate 11. The connection area 121 may be configured to connect to the motherboard (not shown) of the display device. The connection area 121 may contain communication lines between the multiple components and the motherboard of the display device, facilitating signal transmission with the motherboard, such as power signals, data signals, and control signals. Along the first direction X, the size of the connection area 121 may be smaller than the size of the component area 122.

[0051] In an exemplary embodiment, the peripheral area PA may include a bending region (not shown) disposed between the display area AA and a plurality of bonding pads 111. The bending region may extend along a first direction X, and the display substrate 11 may be bent along the bending region, so that the display substrate 11 located on the side of the bending region away from the display area AA is bent to the back side of the display substrate 11, which helps to achieve a narrow bezel. After bending, the flexible circuit board 12 may be bent to the back side of the display substrate 11, and the main board of the display device may be disposed on the back side of the display substrate 11 for connection with the bent connection area 121.

[0052] In an exemplary embodiment, the shape of the display area 100 can be a quadrilateral, a circle, an ellipse, a polygon of other shapes, or an irregular shape, etc. The corners of the display area 100 can be rounded, and the shape of the edge of the display area can be a straight line, a curve, a broken line, etc. This disclosure does not limit these aspects.

[0053] Figure 3 is a schematic diagram of the planar structure of a display area in a display substrate. As shown in Figure 3, the display area AA of the display substrate 11 may include multiple pixel units P arranged in a matrix. At least one pixel unit P may include a first sub-pixel P1 emitting a first color light, a second sub-pixel P2 emitting a second color light, and a third sub-pixel P3 emitting a third color light. Each sub-pixel may include a circuit unit and a light-emitting element. The circuit unit may include at least a pixel driving circuit. The pixel driving circuit is connected to a scan signal line, a data signal line, and a light-emitting signal line, respectively. The pixel driving circuit is configured to receive the data voltage transmitted by the data signal line and output a corresponding current to the light-emitting element under the control of the scan signal line and the light-emitting signal line. The light-emitting element in each sub-pixel is connected to the pixel driving circuit of the sub-pixel, and the light-emitting element is configured to emit light of a corresponding brightness in response to the current output by the connected pixel driving circuit.

[0054] In an exemplary embodiment, the first sub-pixel P1 can be a red sub-pixel (R) that emits red light, the second sub-pixel P2 can be a blue sub-pixel (B) that emits blue light, and the third sub-pixel P3 can be a green sub-pixel (G) that emits green light. In an exemplary embodiment, the shape of the sub-pixels can be rectangular, rhomboid, pentagonal, or hexagonal, and the three sub-pixels can be arranged in a horizontal, vertical, or triangular manner, etc., which is not limited herein.

[0055] In an exemplary embodiment, a pixel unit may include four sub-pixels. For example, the four sub-pixels may include a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel that emits white (W) light. Alternatively, the four sub-pixels may include a red sub-pixel, a blue sub-pixel, and two green sub-pixels. In an exemplary embodiment, the four sub-pixels may be arranged in a horizontally parallel, vertically parallel, square, or diamond shape, etc., and this disclosure does not limit the arrangement.

[0056] Figure 4 is a cross-sectional view of the flexible circuit board in Figure 2 along the AA direction in an exemplary embodiment. As shown in Figure 4, in the direction perpendicular to the flexible circuit board 12, the first thickness H1 of the connection area 121 is less than the second thickness H2 of the component area 122. The first thickness H1 can be the maximum dimension of the connection area 121 in the direction perpendicular to the flexible circuit board 12, and the second thickness H2 can be the maximum dimension of the component area 122 in the direction perpendicular to the flexible circuit board 12. Multiple components (not shown) can be arranged on at least one surface of the component area 122.

[0057] In an exemplary embodiment, the flexible circuit board 12 of the component area 122 may include at least three conductive layers. For example, the flexible circuit board 12 of the component area 122 may include three to six conductive layers. By increasing the number of conductive layers, wiring space can be increased and the area of ​​the flexible circuit board 12 can be reduced. The flexible circuit board 12 of the connection area 121 may include two conductive layers. The connection area 121 is thinner, which helps in subsequent bending and fastening with the motherboard. The material of the conductive layers may include copper. The connection area 121 contains fewer conductive layers and has lower strength compared to the component area 122. Figure 4 illustrates an example where the component area 122 includes three conductive layers (i.e., a three-layer board) and the connection area 121 includes two conductive layers (i.e., a two-layer board). This disclosure does not limit this.

[0058] As shown in Figure 4, the flexible circuit board 12 may include a first conductive layer 202 and a second conductive layer 203 disposed on both sides of the first substrate layer 201. On the side of the first conductive layer 202 away from the first substrate layer 201, a first auxiliary conductive layer 204, a first cover layer (CVL) 206, and a first electromagnetic interference (EMI) layer 207 may be disposed sequentially. The first cover layer 206 can be connected to the first auxiliary conductive layer 204 through a first adhesive layer 205. On the side of the second conductive layer 203 away from the first substrate layer 201, a second substrate layer 209, a third conductive layer 210, a second auxiliary conductive layer 211, a second cover layer 213, and a second electromagnetic interference (EMI) layer 214 may be disposed sequentially. The second substrate layer 209 can be connected to the second conductive layer 203 through a second adhesive layer 208, and the second cover layer 213 can be connected to the second conductive layer 203 through a third adhesive layer 212, a second auxiliary conductive layer 211, and the second conductive layer 203. The second adhesive layer 208, the second substrate layer 209, the third conductive layer 210, and the second auxiliary conductive layer 211 can be located in the component area 122, and the remaining film layers can cover the connection area 121 and the component area 122. The materials of the first substrate layer 201, the second substrate layer 209, the first cover layer 206, and the second cover layer 213 can be polyimide (PI), the first conductive layer 202, the second conductive layer 203, and the third conductive layer 210 can be copper plating, and the first auxiliary conductive layer 204 and the second auxiliary conductive layer 211 can be copper plating. This disclosure does not limit these aspects.

[0059] As shown in Figure 4, during the fabrication process of the flexible circuit board 12, the third conductive layer 210 located in the connection area 121 is directly removed, resulting in a height difference of H2-H1 at the junction of the connection area 121 and the component area 122. The resulting step difference is relatively large. Under stress, the stress of the flexible circuit board 12 tends to concentrate at the junction, and the deformation at the junction is obvious, making it a weak stress area of ​​the entire flexible circuit board 12. During operation of the display device, users need to click on the screen, such as for typing or playing games. The screen undergoes slight deformation when pressed, transmitting the force to the flexible circuit board 12 inside the display device. Each click causes the flexible circuit board 12 to undergo a micro-motion of deformation and recovery. During each micro-motion, the deformation of the flexible circuit board 12 is greatest at the junction. After multiple micro-motions, the conductive layer at the junction is prone to reaching its fatigue limit and cracking first, leading to the breakage of traces near the junction. Communication between the display device's motherboard and the screen is generally transmitted via the flexible circuit board 12. Traces breaking in the flexible circuit board 12 will cause display abnormalities. With the requirements for low weight, small size, and large screen-to-body ratio in display devices, the spatial layout of the display device is becoming more compact. The size of the flexible circuit board 12 is smaller, the dimension of the connection area 121 along the second direction Y is smaller, and the trace length of the connection area 121 is shorter, making it more prone to trace breakage and display abnormalities.

[0060] This disclosure provides a flexible circuit board, including:

[0061] The component area is configured to connect to multiple components;

[0062] The connection area includes multiple traces configured to connect the component to an external device; in the direction perpendicular to the flexible circuit board, the thickness of the component area is greater than the thickness of the connection area.

[0063] The transition area is configured to connect the connection area and the component area;

[0064] The transition zone includes a reinforcing section designed to strengthen the flexible circuit board.

[0065] The flexible circuit board provided in this disclosure strengthens its strength by providing a transition area between the connection area and the component area, and by incorporating reinforcing portions within this transition area. This reduces stress concentration at the junction of the connection and component areas, improves deformation resistance, helps prevent trace breakage near the junction, and extends the lifespan of the flexible circuit board. When the flexible circuit board of this disclosure is applied to a display device, display anomalies caused by trace breakage on the flexible circuit board can be avoided, improving display stability and extending the lifespan of the display device.

[0066] In an exemplary embodiment, the “external device” may be the motherboard of the display device, and this disclosure is not limited thereto.

[0067] Figure 5 is a top view of the flexible circuit board of Figure 2 in the dashed area B of an exemplary embodiment. As shown in Figure 5, the flexible circuit board 12 includes a connection area 121, a component area 122, and a transition area 123, with the transition area 123 located between the connection area 121 and the component area 122. Each of the connection area 121, the component area 122, and the transition area 123 includes at least two conductive layers. The number of conductive layers in the connection area 121 is less than the number of conductive layers in the component area 122. The transition area 123 includes a reinforcing portion 220, which is configured to strengthen the flexible circuit board 12, reduce the stress concentration near the junction of the connection area 121 and the component area 122, improve the deformation resistance of the flexible circuit board 12 at the junction, thereby preventing the traces from breaking near the junction and extending the service life of the flexible circuit board 12. When the flexible circuit board 12 with the structure shown in Figure 5 is applied to a display device, display abnormalities caused by broken traces on the flexible circuit board 12 can be avoided, which helps to improve the stability of the display effect and also helps to extend the life of the display device.

[0068] As shown in Figure 5, the flexible circuit board 12 can extend along a first direction X. The component area 122 is located on one side of the connection area 121 in a second direction Y, and the transition area 123 is located between the connection area 121 and the component area 122. Along the first direction X, the size of the transition area 123 can be equal to the size of the connection area 121 and smaller than the size of the component area 122. Along the second direction Y, the size S of the transition area 123 can be greater than or equal to 2.5 mm and less than or equal to 4.5 mm. For example, the size S of the transition area 123 can be greater than or equal to 3 mm and less than or equal to 4 mm. This disclosure does not impose any limitations on this.

[0069] As shown in Figure 5, the reinforcing section 220 includes a plurality of first sub-reinforcing sections 221. Along the direction from the component area 122 to the connection area 121, the size of the first sub-reinforcing sections 221 gradually increases, and the number of first sub-reinforcing sections 221 gradually increases. The size difference between the plurality of first sub-reinforcing sections 221 arranged along the first direction X can be less than or equal to 10%. For example, the sizes of the plurality of first sub-reinforcing sections 221 arranged along the first direction X can be equal. Figure 5 illustrates that the shape of the plurality of first sub-reinforcing sections 221 is circular. In other embodiments, the shape of the plurality of first sub-reinforcing sections 221 can be one or more of the following shapes: ellipse, triangle, rectangle, rhombus, other quadrilateral and polygonal shapes, and irregular shapes, etc. The edges of the first sub-reinforcing sections 221 can be straight lines, broken lines, curves, etc., and the corners of the first sub-reinforcing sections 221 can be rounded, etc. The shape and size parameters of the plurality of first sub-reinforcing sections 221 can be set as needed, and this disclosure does not impose any limitations on this. By gradually increasing the size and number of multiple first sub-reinforcing parts 221 arranged along the direction from component area 122 to connection area 121, the stress on the transition area 123 can be dispersed, a smooth stress transition can be achieved between connection area 121 and component area 122, the degree of deformation at the junction of connection area 121 and component area 122 during each micro-movement is reduced, the structural strength at the junction is strengthened, the traces near the junction are less likely to break, and the probability of display abnormalities in the display device is reduced.

[0070] Figure 6 is a cross-sectional view of Figure 5 along the CC direction in an exemplary embodiment. The difference between Figure 6 and Figure 4 is only in the transition area 123. The arrangement of the connection area 121 and the component area 122 can be referred to the above description of Figure 4, and will not be repeated here.

[0071] As shown in Figure 6, in the direction perpendicular to the flexible circuit board 12, the thickness of the transition region 123 can be equal to the thickness of the component region 122, both being the second thickness H2. The film layer configuration of the transition region 123 can be the same as that of the component region 122. Multiple first sub-reinforcing portions 221 can be located within the third conductive layer 210 and the second auxiliary conductive layer 211 of the transition region 123. The third conductive layer 210 and the second auxiliary conductive layer 211 at locations where the first sub-reinforcing portions 221 are not located can be removed, and the third adhesive layer 212 can be filled between the multiple first sub-reinforcing portions 221.

[0072] In other embodiments, the component region 122 may also include at least one conductive layer located on the side of the third conductive layer 210 away from the second substrate layer 209, and a plurality of first sub-reinforcing portions 221 may penetrate the at least one conductive layer. The surface of the second substrate layer 209 may be exposed between the plurality of first sub-reinforcing portions 221. The first sub-reinforcing portions 221 may be located in which film layers as needed, and this disclosure does not limit this.

[0073] Figure 7 is a top view of the flexible circuit board of Figure 2 in the dashed area B in another exemplary embodiment. The difference between Figure 7 and Figure 5 is that the arrangement of the multiple first sub-reinforcing parts 221 is different. The rest can be referred to the description of Figure 5 above, and will not be repeated here.

[0074] As shown in Figure 7, the size of the first sub-reinforcing portion 221 gradually decreases along the direction from the component area 122 to the connection area 121, and the number of the first sub-reinforcing portions 221 also gradually decreases. The shape and size of the multiple first sub-reinforcing portions 221 can be referred to the description of Figure 5 above, and will not be repeated here. By setting the size and number of the multiple first sub-reinforcing portions 221 arranged along the direction from the component area 122 to the connection area 121 to gradually decrease, the stress on the transition area 123 can be dispersed, a smooth stress transition can be achieved between the connection area 121 and the component area 122, the degree of deformation at the junction of the connection area 121 and the component area 122 during each micro-movement can be reduced, the structural strength at the junction can be strengthened, the traces near the junction are less likely to break, and the probability of display abnormalities in the display device can be reduced.

[0075] Figure 8 is a cross-sectional view of Figure 7 along the CC direction in an exemplary embodiment. The only difference between Figure 8 and Figure 6 is the size of the adjacent first sub-reinforcing part 221. The rest can be referred to the description of Figure 6 above, and will not be repeated here.

[0076] Figure 9 is a top view of the flexible circuit board of Figure 2 in the dashed area B in another exemplary embodiment. The difference between Figure 9 and Figure 5 is the setting of the reinforcing part 220. The rest can be referred to the description of Figure 5 above, and will not be repeated here.

[0077] As shown in Figure 9, the reinforcing portion 220 may include a plurality of second sub-reinforcing portions 222, which may be arranged sequentially along a first direction X. Each second sub-reinforcing portion 222 may be a strip extending along a second direction Y, and may penetrate the transition region 123 along the second direction Y. The size of the second sub-reinforcing portions 222 gradually decreases along the first direction X in the direction from the component region 122 to the connection region 121. In Figure 9, the ends of the plurality of second sub-reinforcing portions 222 near the component region 122 may contact each other, forming a sawtooth-shaped reinforcing portion 220. In other embodiments, the plurality of second sub-reinforcing portions 222 may be arranged at intervals along the first direction X. The minimum distance between adjacent second sub-reinforcing portions 222 may be a first spacing, the size of which can be set as needed. For example, at least two first spacings may be equal; this disclosure does not limit this. Figure 9 illustrates an example where multiple second sub-reinforcing sections 222 are trapezoidal in shape. In other embodiments, the shape and size of the multiple second sub-reinforcing sections 222 can be set as needed. The edges of the second sub-reinforcing sections 222 can be straight lines, broken lines, curves, etc., and the corners of the second sub-reinforcing sections 222 can be rounded, etc. This disclosure does not impose any limitations on this. By setting multiple second sub-reinforcing sections 222 to be strips extending along the second direction Y, and the size of the second sub-reinforcing sections 222 gradually decreases along the first direction X in the direction from the component area 122 to the connection area 121, the stress on the transition area 123 can be dispersed, a smooth transition of stress can be achieved between the connection area 121 and the component area 122, the degree of deformation at the junction of the connection area 121 and the component area 122 during each micro-movement is reduced, the structural strength at the junction is strengthened, the traces near the junction are less likely to break, and the probability of display abnormalities in the display device is reduced.

[0078] Figure 10 is a cross-sectional view along the CC direction of Figure 9 in an exemplary embodiment, illustrating a portion of the structure of a single second sub-reinforcement 222. The difference between Figure 10 and Figure 4 lies only in the transition region 123. The arrangement of the connection region 121 and the component region 122 can be referred to the aforementioned description of Figure 4, and will not be repeated here.

[0079] As shown in Figure 10, in the direction perpendicular to the flexible circuit board 12, the thickness of the transition region 123 can be equal to the thickness of the component region 122, both being the second thickness H2. The film layer configuration of the transition region 123 can be the same as that of the component region 122. Multiple second sub-reinforcing portions 222 can be located within the third conductive layer 210 and the second auxiliary conductive layer 211 of the transition region 123. The third conductive layer 210 and the second auxiliary conductive layer 211 at locations where the second sub-reinforcing portions 222 are not located can be removed, and the third adhesive layer 212 can be filled between the multiple second sub-reinforcing portions 222.

[0080] In other embodiments, the component region 122 may also include at least one conductive layer located on the side of the third conductive layer 210 away from the second substrate layer 209, and a plurality of second sub-reinforcing portions 222 may penetrate the at least one conductive layer. The surface of the second substrate layer 209 may be exposed between the plurality of second sub-reinforcing portions 222. The locations of the second sub-reinforcing portions 222 in which film layers are located may be determined as needed, and this disclosure does not limit this.

[0081] Figure 11 is a top view of the flexible circuit board of Figure 2 in the dashed area B in another exemplary embodiment. The difference between Figure 11 and Figure 9 is that the number of second sub-reinforcing parts 222 is smaller, and the plurality of second sub-reinforcing parts 222 are an integral structure on the side near the component area 122. The rest can be referred to the description of Figure 9 above, and will not be repeated here.

[0082] In an exemplary embodiment, the dimensions of the integral structure of the plurality of second sub-reinforcing portions 222 on the side near the component area 122 and the dimensions of the portions of the plurality of second sub-reinforcing portions 222 that are separated from each other can be set as needed, and this disclosure does not limit this.

[0083] Figure 12 is a cross-sectional view of Figure 11 along the CC direction in an exemplary embodiment. The difference between Figure 12 and Figure 4 is only in the transition area 123. The arrangement of the connection area 121 and the component area 122 can be referred to the above description of Figure 4, and will not be repeated here.

[0084] As shown in Figure 12, in the direction perpendicular to the flexible circuit board 12, the thickness of the transition region 123 can be less than the second thickness H2 of the component region 122 and greater than the first thickness H1 of the connection region 121. Multiple second sub-reinforcing portions 222 can be located within the transition region 123 as the second adhesive layer 208 and the second substrate layer 209. The third conductive layer 210 and the second auxiliary conductive layer 211 within the transition region 123 can be removed, thereby reducing the thickness of the transition region 123. By setting the second thickness H2 of component area 122, the thickness of transition area 123, and the first thickness H1 of connection area 121 to gradually decrease in sequence, the step difference between component area 122 and connection area 121 is reduced, which helps to reduce the stress concentration at the junction of component area 122 and connection area 121. Furthermore, by setting multiple second sub-reinforcing parts 222 in the second substrate layer 209, the stress in transition area 123 is dispersed, the deformation of transition area 123 during each micro-movement is reduced, and the structural strength at the junction is strengthened, making the traces near the junction less prone to breakage and reducing the probability of display abnormalities in the display device.

[0085] In other embodiments, the component region 122 may also include at least one conductive layer located on the side of the third conductive layer 210 away from the second substrate layer 209, and the transition region 123 may include fewer conductive layers than the third conductive layer 210. This disclosure does not limit this.

[0086] Figure 13 is a cross-sectional view of Figure 11 along the CC direction in another exemplary embodiment. The difference between Figure 13 and Figure 12 is that the thickness of the transition region 123 decreases in a stepped manner along the direction from the component region 122 to the connection region 121. The rest of the structure can be referred to the description of Figure 12 above, and will not be repeated here.

[0087] As shown in Figure 13, a plurality of second sub-reinforcing portions 222 may be located within the transition region 123, comprising the second adhesive layer 208, the second substrate layer 209, the third conductive layer 210, and the second auxiliary conductive layer 211. The portion of the multiple second sub-reinforcing portions 222 that is integrally formed near the component region 122 may be located within the second adhesive layer 208, the second substrate layer 209, the third conductive layer 210, and the second auxiliary conductive layer 211. The portions of the multiple second sub-reinforcing portions 222 that are separated from each other may be located within the second adhesive layer 208 and the second substrate layer 209, such that the thickness of the transition region 123 decreases in a stepped manner along the direction from the component region 122 to the connection region 121.

[0088] In other embodiments, the component region 122 and the transition region 123 may also include at least one conductive layer located on the side of the third conductive layer 210 away from the second substrate layer 209. When the transition region 123 includes more conductive layers, the thickness of the transition region 123 may be in a more stepped shape in the direction from the component region 122 to the connection region 121, which is not limited in this disclosure.

[0089] In the exemplary embodiments, the structures in Figures 5 to 13 can be combined arbitrarily with each other, and this disclosure does not limit them.

[0090] The flexible circuit board provided in this disclosure requires minimal modification to the original manufacturing process and is suitable for widespread application. It can be used not only in display devices but also in other types of electronic products, and this disclosure does not impose any limitations on it.

[0091] This disclosure also provides a display device, including a display substrate and the flexible circuit board described in any of the above embodiments. The display device can be any product or component with display functionality, such as an OLED display, QLED display, LED display, mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or navigator; this disclosure is not limited thereto.

[0092] In an exemplary embodiment, the component area of ​​the flexible circuit board can be bonded to the display substrate, and the connection area of ​​the flexible circuit board can be connected to the motherboard of the display device. This disclosure does not limit this.

[0093] Although embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A flexible circuit board, comprising: The component area is configured to connect to multiple components; The connection area includes multiple traces, which are configured to connect the component to an external device; In the direction perpendicular to the flexible circuit board, the thickness of the component area is greater than the thickness of the connection area; The transition area is configured to connect the connection area and the component area; The transition zone includes a reinforcing section designed to strengthen the flexible circuit board.

2. The flexible circuit board according to claim 1, wherein, In a direction perpendicular to the flexible circuit board, the connection area, the component area, and the transition area each include at least two conductive layers; The thickness of the component area is greater than the thickness of the connection area, including: the number of conductive layers in the connection area is less than the number of conductive layers in the component area.

3. The flexible circuit board according to claim 2, wherein, In a direction perpendicular to the flexible circuit board, the component area includes a first conductive layer, a first substrate layer, a second conductive layer, a second substrate layer, and a third conductive layer stacked sequentially, and the connection area includes the first conductive layer and the second conductive layer.

4. The flexible circuit board according to claim 3, wherein, In a direction perpendicular to the flexible circuit board, the transition region includes the first conductive layer, the first substrate layer, the second conductive layer, and the second substrate layer, with the reinforcing portion located in the second substrate layer.

5. The flexible circuit board according to claim 3, wherein, In a direction perpendicular to the flexible circuit board, the transition region includes the first conductive layer, the first substrate layer, the second conductive layer, the second substrate layer, and the third conductive layer; the reinforcing portion is located in the third conductive layer, or the reinforcing portion is located in the third conductive layer and the second substrate layer.

6. The flexible circuit board according to claim 4 or 5, wherein, The reinforcing portion includes a plurality of first sub-reinforcing portions, the size of which gradually increases along the direction from the component area to the connection area, and the number of the first sub-reinforcing portions gradually increases.

7. The flexible circuit board according to claim 4 or 5, wherein, The reinforcing portion includes a plurality of first sub-reinforcing portions, the size of the first sub-reinforcing portions gradually decreases along the direction from the component area to the connection area, and the number of the first sub-reinforcing portions gradually decreases.

8. The flexible circuit board according to claim 4 or 5, wherein, The reinforcing portion includes a plurality of second sub-reinforcing portions that penetrate the transition region. The plurality of second sub-reinforcing portions are arranged sequentially along the extension direction of the transition region. Along the direction from the component area to the connection area, the size of the second sub-reinforcing portions gradually decreases along the arrangement direction.

9. The flexible circuit board according to claim 8, wherein, When the reinforcement portion is located between the third conductive layer and the second substrate layer, the thickness of the transition region decreases in a stepped manner along the direction from the component area to the connection area.

10. The flexible circuit board according to claim 8, wherein, Along the arrangement direction, at least two second sub-reinforcing portions are in contact with each other at one end near the component region; or, along the arrangement direction, a plurality of second sub-reinforcing portions are spaced apart from each other.

11. The flexible circuit board according to claim 8, wherein, Along the arrangement direction, the side of the plurality of second sub-reinforcement portions near the component area is an integral structure.

12. The flexible circuit board according to claim 11, wherein, A portion of the integral structure of the plurality of second sub-reinforcing portions is located in the second substrate layer and the third conductive layer, while the remaining portion of the plurality of second sub-reinforcing portions is located in the second substrate layer.

13. The flexible circuit board according to claim 1, wherein, The flexible circuit board extends along a first direction, and the component area is located on one side of the connection area in a second direction, wherein the first direction and the second direction intersect. Along the second direction, the size of the transition region is greater than or equal to 2.5 mm and less than or equal to 4.5 mm.

14. The flexible circuit board according to claim 13, wherein, Along the first direction, the dimensions of the transition region and the connection region are smaller than the dimensions of the component region.

15. A display device comprising a display substrate and a flexible circuit board as claimed in any one of claims 1-14.

Images