Circuit board, display module and electronic device

Abstract

Embodiments of the present application provide a kind of circuit board, display module and electronic equipment, applied to display technical field.The circuit board includes: substrate and the circuit layer being set on substrate;Substrate includes strain detection layer, and strain detection layer is insulated with the circuit layer and is stacked;Strain detection layer is provided with the multiple sensing units of array arrangement;Interlayer conductive structure, through the insulating region between strain detection layer and circuit layer, multiple sensing units are electrically connected with circuit layer by interlayer conductive structure.The present application is integrated with the strain detection layer that is insulated with the circuit layer in the circuit board, and realizes the transmission of sensing signal on strain detection layer by using interlayer conductive structure, when the circuit board is made as the flexible circuit board that is bent in display module, the real strain state of the flexible circuit board that is bent can be fed back in real time;When the circuit board is applied to flexible display panel, the electrical signal on flexible display panel can be monitored using sensing signal, to carry out electrical failure analysis to flexible display panel.

Description

Technical Field

[0001] This invention relates to the field of display technology, specifically to a circuit board, a display module, and an electronic device. Background Technology

[0002] As display panels evolve towards thinner, lighter, higher resolution, and ultra-narrower bezels, the structural reliability of circuit boards such as chip-on-film (COF) and flexible printed circuits (FPC), which are core components connecting the display panel and the driving circuit, is of paramount importance. During the bonding process between the circuit board and the display panel or printed circuit board assembly, as well as subsequent bending and assembly, complex stress deformations occur within the material.

[0003] Strain values ​​play a crucial role in mechanical design and analysis, often serving as indicators of critical failure locations. Specific degrees of deformation are frequently the direct cause of failure modes such as solder joint cracking, circuit breaks, or short circuits. Current technologies cannot provide real-time feedback and display of the actual strain state of bent circuit boards and flexible panels within modules, thus failing to guarantee in-situ real-time monitoring of circuit board deformation and electrical status, and early warning of electrical failure risks. Summary of the Invention

[0004] This invention provides a circuit board, a display module, and an electronic device to solve the problem that existing display modules cannot provide real-time feedback on the actual strain state of bent circuit boards or flexible panels.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: One aspect of the present invention provides a circuit board, including a substrate and a circuit layer disposed on the substrate; wherein the substrate includes a strain detection layer, the strain detection layer being insulated from and stacked with the circuit layer; a plurality of sensing units arranged in an array are disposed on the strain detection layer; an interlayer conductive structure penetrates the insulating region between the strain detection layer and the circuit layer, and the plurality of sensing units are electrically connected to the circuit layer through the interlayer conductive structure.

[0006] In one embodiment, the substrate further includes a substrate layer stacked with the strain detection layer, wherein the strain detection layer is disposed on the side of the substrate layer opposite to the circuit layer.

[0007] In one implementation, the substrate layer is a flexible material layer.

[0008] In one embodiment, the strain detection layer is wrapped with an insulating protective layer, and the strain detection layer and the external insulating protective layer are combined to form the substrate.

[0009] In one implementation, each of the multiple sensing units includes multiple sub-units, which are respectively disposed in different regions. Each sub-unit includes sensing lines arranged in a serpentine pattern, and the sensing lines of the multiple sub-units of a sensing unit are interconnected.

[0010] In one implementation, among the plurality of sub-units of the sensing unit, the sensing circuit includes parallel sub-circuits, which are any of the following: curved, horizontal, vertical, and inclined relative to the horizontal.

[0011] In one embodiment, a conductive contact pad is provided on the circuit layer, and the sensing unit is connected to the conductive contact pad through the interlayer conductive structure; and / or, a first functional circuit is provided on the circuit layer, and the sensing unit is connected to the first functional circuit through the interlayer conductive structure.

[0012] In one implementation, the first functional circuit includes IC chip power supply lines and / or IC chip redundant pin lines.

[0013] In one embodiment, the substrate includes at least two mutually insulated and stacked strain detection layers, and the sensing unit of each strain detection layer is electrically connected to the circuit layer through different interlayer conduction structures.

[0014] In one implementation, multiple sensing units are arranged in an array along the row and column directions. Multiple sensing units in each row are connected by a walk line, and multiple sensing units in each column are connected by a column walk line. The walk lines and column walk lines are insulated from each other.

[0015] In one implementation, a switching element is connected in series on each walking line and each column walking line, one or more walking lines are grouped together and connected to a signal input terminal, and one or more column walking lines are grouped together and connected to a signal acquisition terminal.

[0016] In one implementation, the circuit layer includes a strain detection circuit, and a plurality of the sensing units are connected to the strain detection circuit through the interlayer conduction structure.

[0017] In one embodiment, the interlayer conductive structure includes a vertical through-hole.

[0018] In addition, the present invention also provides a display module, including a display panel and a circuit board as described above, wherein the circuit board is electrically connected to the display panel.

[0019] In one embodiment, the display panel includes a bonding area disposed on a first end face, the first end face being the display surface of the display panel, and the display module further includes a printed circuit board assembly (PCBA) component disposed on a second end face of the display panel opposite to the first end face; wherein the circuit board is in a bent state, and the PCBA component and the bonding area are electrically connected to the circuit layer respectively.

[0020] In one embodiment, the display panel is a flexible display panel, including a planar portion and a bent portion, wherein a bonding area is provided at the end of the bent portion away from the planar portion; the circuit board is arranged parallel to the planar portion, and the circuit layer is electrically connected to the bonding area.

[0021] In addition, the present invention also provides an electronic device including a display module as described above.

[0022] At least one of the above technical solutions of the present invention has the following beneficial effects: The circuit board described in this embodiment of the invention integrates a strain detection layer that is insulated from the circuit layer, and utilizes an interlayer conductive structure to transmit the induced signal on the strain detection layer, thus constructing an internal strain monitoring system within the circuit board. This enables the circuit board itself to sense mechanical deformation. When the circuit board is used as a flexible circuit board in a display module, it can provide real-time feedback on the actual strain state of the flexible circuit board. When the circuit board is applied to a flexible display panel, it can use the induced signal to monitor the electrical signals on the flexible display panel to perform electrical failure analysis on the flexible display panel. Attached Figure Description

[0023] Figure 1 This is a cross-sectional structural diagram of the circuit board described in Embodiment 1 of this application; Figure 2 This is one of the structural schematic diagrams of a display module using the circuit board described in the embodiments of this application; Figure 3 This is a second schematic diagram of the structure of a display module using the circuit board described in the embodiments of this application; Figure 4 This is the third schematic diagram of the structure of the display module using the circuit board described in the embodiments of this application; Figure 5 This is a cross-sectional view of the circuit board described in Embodiment 2 of this application; Figure 6 This is one of the schematic diagrams showing the arrangement of sensing units on the circuit board in the embodiments of this application; Figure 7 This is a second schematic diagram of the arrangement of sensing units on the circuit board in an embodiment of this application; Figure 8This is the third schematic diagram of the arrangement of sensing units on the circuit board in this embodiment of the application; Figure 9 This is one of the circuit connection diagrams of the sensing unit disposed on the circuit board in the embodiments of this application; Figure 10 This is a second schematic diagram of the circuit connection of the sensing unit on the circuit board in an embodiment of this application; Figure 11 This is the third schematic diagram of the circuit connection of the sensing unit on the circuit board in the embodiments of this application; Figure 12 This is a schematic diagram of the layout structure of the sensing unit in an embodiment of this application; Figure 13 This is one of the schematic diagrams showing the circuit layout of the sensing unit in the embodiments of this application; Figure 14 This is the second schematic diagram of the circuit layout of the sensing unit in the embodiments of this application; Figure 15 This is the third schematic diagram of the circuit layout of the sensing unit in the embodiments of this application; Figure 16 This is the fourth schematic diagram of the circuit layout of the sensing unit in the embodiments of this application; Figure 17 This is the fifth schematic diagram of the circuit layout of the sensing unit in the embodiments of this application; Figure 18 A schematic diagram illustrating the principle of the strain inference model of the sensing unit; Figure 19 This is a cross-sectional view of the circuit board described in Embodiment 3 of this application; Figure 20 This is a cross-sectional structural diagram of the circuit board described in Embodiment 4 of this application; Figure 21 This is the fourth schematic diagram of the structure of the display module using the circuit board described in the embodiments of this application. Detailed Implementation

[0024] 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, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "a" or "one," and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "connected" or "linked," and similar terms, are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship also changes accordingly.

[0026] To address the issue that existing display modules cannot provide real-time feedback on the actual strain state of bent circuit boards and flexible panels, this invention provides a circuit board that integrates a strain detection layer insulated from the circuit layers. By utilizing interlayer conductive structures to transmit induced signals on the strain detection layer, an internal strain monitoring system is constructed within the circuit board. This enables the circuit board itself to sense mechanical deformation. When the circuit board is used as a bent flexible circuit board in a display module, it can provide real-time feedback on the actual strain state of the bent flexible circuit board. When the circuit board is applied to a flexible display panel, the induced signals can be used to monitor the electrical signals on the flexible display panel for electrical failure analysis.

[0027] Figure 1 This is a cross-sectional view of the circuit board provided in Embodiment 1 of the present invention. Figures 2 to 4 This is a schematic diagram showing the different usage states of the circuit board in this embodiment. (See attached diagram.) Figures 1 to 4 As shown, an embodiment of the present invention provides a circuit board, the circuit board 100 including a substrate 110 and a circuit layer 120 disposed on the substrate 110. The substrate 110 includes a strain detection layer 111, the strain detection layer 111 is insulated from the circuit layer 120 and is stacked, and a plurality of sensing units are disposed on the strain detection layer 111. The circuit board 100 also includes an interlayer conductive structure 130, which penetrates the insulation area between the strain detection layer 111 and the circuit layer 120. Multiple sensing units are electrically connected to the circuit layer 120 through the interlayer conductive structure 130.

[0028] Optionally, the strain detection layer 111 serves as a functional embedded layer on the circuit board 100. The material is typically a conductive or semiconductor material with piezoresistive effect or geometric deformation sensitivity, which can respond to mechanical deformation through changes in its own resistance value.

[0029] In one embodiment of the circuit board described in this invention, the circuit board 100 is a flexible circuit board, combined with... Figures 2 to 4 As shown, the circuit board 100 is used in a foldable display module. The display module using this circuit board 100 includes a display panel 300, the circuit board 100, and a PCBA 500. The circuit board 100 is electrically connected to both the display panel 300 and the PCBA 500, with one circuit board 100 connected to one PCBA 500. The number and shape of the circuit boards 100 and PCBA 500 on the display panel 300 can vary depending on the size and resolution of the display module.

[0030] Optionally, PCBA 500 can be configured with, but is not limited to, one or more of the following: controller, memory, power supply, analog-to-digital converter, amplifier, etc.

[0031] like Figure 3 As shown, the display panel 300 may include an array substrate 211 and a display layer 212 disposed on the array substrate 211. The circuit board 100 is connected to the array substrate 211 and the PCBA 500 via metal contact pads 1. Specifically, at the end of the circuit board 100 connected to the array substrate 211 via the metal contact pads 1, an outer lead bonding (OLB) is used; at the end of the circuit board 100 connected to the PCBA 500 via the metal contact pads 1, an inner lead bonding (ILB) is used.

[0032] The circuit board 100 has a chip 2 on its circuit layer 120. On the circuit layer 120 of the circuit board 100, in the area outside the metal contact pad 1, chip 2 and chip 2 traces, there is a solder resist layer (SR) to provide isolation and protection.

[0033] One embodiment of the circuit board described in this invention is as follows: Figure 1 As shown, the substrate 110 also includes a substrate layer 112 stacked with the strain detection layer 111, the strain detection layer 111 being disposed on the side of the substrate layer 112 facing away from the circuit layer 120. In this embodiment, the substrate layer 112 provides basic support for the circuit layer 120. In this embodiment, the substrate layer 112 is a flexible material layer, giving the circuit board 100 a bendable feature, enabling it to be bent to connect the display panel 300 and the PCBA 500.

[0034] In some embodiments, the substrate layer 112 may optionally be made of a polymer film material such as polyimide (PI), polyethylene terephthalate (PET), or polyethylene naphthalate (PEN). Using a flexible material for the substrate layer 112 gives the circuit board 100 the overall mechanical properties of being bendable and foldable, adapting to the dynamic deformation requirements of the flexible display module during assembly and use. When the circuit board 100 is repeatedly bent along with the display panel, the flexible substrate layer 112 can not only withstand its own tensile and compressive stress without breaking, but also act as a buffer layer to absorb some of the external impact energy, protecting the structural integrity of the internal circuit layer 120 and strain detection layer 111, ensuring that the sensing unit 200 maintains stable electrical performance and measurement accuracy under long-term dynamic loads.

[0035] Another embodiment of the circuit board described in this invention is as follows: Figure 5 As shown, the strain detection layer 111 is wrapped with an insulating protective layer 400. The strain detection layer 111 is insulated from the circuit layer 120. With this implementation structure, the strain detection layer 111 and the outer insulating protective layer 400 are combined to form a substrate 110.

[0036] Unlike the structure in which the strain detection layer 111 is disposed on the substrate layer 112, this implementation structure removes the substrate layer 112 in the circuit board 100 and uses the insulating protective layer 400 to directly wrap the strain detection layer 111 to replace the traditional substrate layer 112. While ensuring electrical insulation and mechanical protection, it significantly reduces the overall thickness of the circuit board and meets the design requirements of ultra-thin design.

[0037] It should be noted that the above Figure 1 and Figure 5 As shown, the insulation structure between the strain detection layer 111 and the circuit layer 120 is only one of two exemplary layouts and is not limited thereto. In other embodiments not shown, the strain detection layer 111 can also be embedded between any adjacent insulation layers of the multilayer circuit structure, as long as the strain detection layer and the circuit layer are stacked and electrically insulated from each other, to adapt to different packaging stacking requirements.

[0038] See Figure 1 and Figure 5As shown, in this embodiment of the invention, the circuit board 100 further includes an interlayer conductive structure 130, which provides a vertical electrical interconnection path between the strain detection layer 111 and the circuit layer 120, solving the signal transmission problem between these functional layers. As a preferred implementation, the interlayer conductive structure 130 includes a vertical via. For example, the vertical via can be etched through an insulating layer or substrate layer, and the electrical connection between the strain detection layer 111 and the circuit layer 120 can be achieved by filling with a conductive material. It should be understood that although a vertical via is preferred in this embodiment, in other embodiments, the interlayer conductive structure 130 can also use conductive silver paste vias, metal bumps, or other equivalent structures capable of achieving vertical interlayer conduction, as long as it can reliably establish an electrical connection between the sensing unit 200 of the strain detection layer 111 and the circuit layer 120.

[0039] In embodiments of the present invention, such as Figure 6 and Figure 7 As shown, the strain detection layer 111 is provided with multiple sensing units 200 arranged in an array. The multiple sensing units 200 constitute the basic nodes of the strain sensing network. They are distributed in an array within a preset area of ​​the strain detection layer 111 to collect strain information of the local area.

[0040] In one implementation, multiple sensing units 200 are arranged in an array along row and column directions. Multiple sensing units 200 in each row are connected by a walk line 220, and multiple sensing units 200 in each column are connected by a column walk line 230. The walk lines 220 and column walk lines 230 are mutually insulated. Specifically, as... Figure 6 As shown, this matrix topology organizes discrete sensing units 200 into a regular array structure. The routing lines 220 and column routing lines 230 are orthogonally distributed in space, but are electrically isolated at the intersections by interlayer insulation media. Controlled electrical connections are established only at the nodes of the preset sensing units 200 through vias or contact pads.

[0041] It should be understood that although a regular orthogonal rectangular grid is shown in the figure, in other embodiments, depending on the actual contour of the circuit board 100 or the requirements of the avoidance area, the array may also adopt a trapezoidal, fan-shaped, or non-uniformly spaced arrangement, such as... Figure 8 As shown, as long as the logical topology of row and column addressing remains unchanged, it is sufficient.

[0042] Furthermore, such as Figure 9As shown, a switching element 240 is connected in series on each walk line 220 and each column walk line 230. One or more walk lines 220 are grouped together and connected to a signal input terminal, and one or more column walk lines 230 are grouped together and connected to a signal acquisition terminal, used to realize the input of control signals and the acquisition of sensing signals. Optionally, the switching element 240 can be one or more of thin-film transistors (TFTs), PIN diodes, and MEMS switches. By connecting the switching element 240 in series on each walk line 220 and each column walk line 230, time-division scanning control of multiple sensing units 200 can be realized, without the need to supply power to all sensing units 200 at the same time, thereby significantly reducing instantaneous power consumption and realizing efficient reading and low power management of large-scale array sensing units.

[0043] In this embodiment, multiple walk lines 220 or multiple column walk lines 230 can be combined and connected to the same external interface to further optimize the number of pins. For example, three adjacent walk lines 220 can be grouped together and share a single drive signal input terminal, and activated sequentially through time-division multiplexing or encoding; or multiple column walk lines 230 can be converged to an analog multiplexer before entering the ADC for sampling. The specific number and combination of groups can be flexibly adjusted according to actual resolution requirements and processing capabilities.

[0044] In one embodiment of the present invention, optionally, as shown... Figure 10 and Figure 11 As shown, the output leads 20 of the row and column traces connecting the sensing unit 200 are output independently. Multiple output leads 20 can be output from one side and extend in one direction on the strain detection layer 111; or they can be output from multiple sides and extend in multiple directions on the strain detection layer 111. The specific output leads 20 can be determined according to the circuit layout requirements of the strain detection layer 111.

[0045] As one implementation method, such as Figure 12 As shown, in the multiple sensing units 200, each sensing unit 200 includes multiple sub-units 210, which are respectively disposed in different areas. Each sub-unit 210 includes sensing lines 201 arranged in a serpentine pattern, and the sensing lines 201 of the multiple sub-units 210 of a sensing unit 200 are interconnected. Using this method, multiple sub-units 210 distributed in different areas are interconnected to form a composite sensing node, enabling a single sensing unit 200 to cover a larger monitoring area.

[0046] Furthermore, to achieve comprehensive perception of complex stress states, in a sensing unit 200, among its multiple sub-units 210, the sensing circuit 201 includes parallel sub-circuits, which can be curved, horizontal, vertical, or inclined relative to the horizontal. For example... Figures 13 to 17As shown, within a sensing unit 200, sub-units 210 in different regions can have different routing directions. For example, as Figure 12 and Figure 13 As shown, a sensing unit 200 includes four regions, and the traces of the sub-units 210 in the four regions extend horizontally (X-axis) and are mainly used to sense tensile or compressive strain along the X-axis; or, extend vertically (Y-axis) and are used to sense tensile or compressive strain along the Y-axis, and the two regions extending in the same direction are staggered; in another embodiment, as... Figure 14 As shown, in a sensing unit 200, four regions are each tilted at 45°, 135°, -135°, and -45° relative to the positive X-axis direction, respectively, to sense stress at that specific angle; in another embodiment, as... Figure 15 As shown, a sensing unit 200 has four regions, including a region where the traces of the subunit 210 extend horizontally (X-axis), a region where the traces extend vertically (Y-axis), a region where the traces extend at a -135° angle, and a region where the traces extend at a -45° angle. Alternatively, as... Figure 16 As shown, the traces of the sub-units 210 in the four regions extend along the horizontal direction (X-axis); or, as... Figure 17 As shown, the traces of the sub-units 210 in the four regions are arranged in a curved arc, and the curvature of the traces is different in different regions.

[0047] By adopting the above-described implementation structure and integrating sub-units 210 with multiple vector directions within the same sensing unit 200, stress changes in different directions can be identified, enabling refined and comprehensive in-situ monitoring of the stress state of the circuit board 100.

[0048] More importantly, the sensing lines 201 within each sub-unit 210 are arranged in a serpentine pattern. This geometric configuration was not designed merely for aesthetics or ease of wiring, but rather as a targeted optimization based on the physical principles of strain effects. Figure 18 As shown, and based on the strain effect formula for metallic conductors: ; ; ; ; ; ; .

[0049] in, This is the original resistance value of the conductor (i.e., the trace). The original length of the conductor. Poisson's ratio, R is the resistivity, H is the original width of the conductor, and R is the resistivity. · L represents the resistance value under tensile stress. · H represents the conductor length under tensile stress. · The conductor width changes under tensile conditions. This represents the stress value.

[0050] As shown in the formula, the relationship between the deformation length L of the conductor and the resistance R is measured by K, which is determined by the conductor material selection itself. Corresponding thresholds can be set according to the different material properties.

[0051] It should be understood that, such as Figure 12 As shown, although in this embodiment of the invention, the sensing line 201 of the sensing unit 200 is a regular rectangular serpentine line, in other embodiments, the sensing line 201 may also adopt a wavy, sawtooth, or other tortuous shape that can achieve a multiplication of length. As long as its essence is to improve strain sensitivity by increasing the path length, it is within the protection scope of this invention.

[0052] In this embodiment of the invention, optionally, the circuit layer 120 includes a strain detection circuit, and multiple sensing units 200 are connected to the strain detection circuit through an interlayer conductive structure 130. Optionally, the strain detection circuit can be formed by etching copper foil traces in the circuit layer 120, including but not limited to a Wheatstone bridge circuit, a differential amplifier circuit, or an analog-to-digital converter interface circuit. By connecting the sensing units 200 to the strain detection circuit of the circuit layer 120, strain signals on the sensing units 200 can be monitored and acquired.

[0053] Based on the circuit board of the above embodiments of the present invention, the embodiments of the present invention further describe in detail the electrical connection mode and functional expansion between the sensing unit 200 and the circuit layer 120. As one implementation method, such as... Figure 1 As shown, a metal contact pad 1 is disposed on the circuit layer 120, and the sensing unit 200 is connected to the metal contact pad 1 through the interlayer conductive structure 130; and / or, as shown Figure 19 As shown, a first functional line is provided on the circuit layer 120, and the sensing unit 200 is connected to the first functional line through the interlayer conduction structure 130. In some embodiments, the first functional line includes IC chip power supply lines and / or IC chip redundant pin lines.

[0054] When the sensing unit 200 is connected to the dedicated metal contact pad 1 and the redundant pin lines of the IC chip, the sensing unit 200 has an independent signal transmission channel; when the sensing unit 200 is connected to the power supply line of the IC chip, it can be directly powered by the IC to achieve sharing with the internal power network of the IC chip. This realizes the reuse of the existing resources of the line layer 120, which not only saves wiring space, but more importantly, gives the sensing unit 200 the diagnostic capability to correlate with the state of the circuit under test.

[0055] It should be understood that the connection methods between the aforementioned sensing units and the circuit layer 120 are not mutually exclusive. In actual products, one method can be used alone according to monitoring needs, or they can be used in combination in different areas of the same circuit board 100 to achieve optimal allocation of monitoring resources.

[0056] In some embodiments, optionally, the substrate 110 includes at least two mutually insulated and stacked strain detection layers 111, and the sensing unit 200 of each strain detection layer 111 is electrically connected to the circuit layer 120 through different interlayer conductive structures 130. Figure 20 As shown, taking the strain detection layer 111 wrapped by an insulating protective layer as an example, the strain detection layer 111 with two layers can be used for different sensing functions. For example, the sensing unit 200 in the lower strain detection layer 111 near the circuit layer 120 or the IC chip mounting area can be connected to the IC chip power supply line. Taking advantage of its proximity to the heat source and stress concentration area, it is specifically responsible for the electrical failure diagnosis and local thermomechanical coupling monitoring of the IC chip. At the same time, the sensing unit 200 in the upper strain detection layer 111 far away from the circuit layer 120 can be connected to the redundant pin lines of the IC chip or the independent metal contact pad 1, so that it is protected from the interference of the complex electric field of the lower layer and focuses on sensing the overall macroscopic bending, torsional deformation and environmental impact of the circuit board 100.

[0057] It should be noted that the above-described strain detection layer structure is for illustrative purposes only and is not intended to be limiting. Where process conditions permit, three or more strain detection layers 111 can be configured. The thickness of the insulation material between each layer, the density of the sensing units 200, and the connection pattern can all be independently designed and optimized according to the specific monitoring objectives.

[0058] The circuit board described in this embodiment of the invention is applied to... Figure 2 and Figure 3 The following description uses a display panel as an example of the embodiment shown. In another embodiment of the present invention, as... Figure 21As shown, the circuit board of each embodiment of the present invention can also be applied to a flexible display panel, including a planar portion 11 and a bent portion 12. A bonding area 13 is provided at the end of the bent portion 12 away from the planar portion 11. The circuit board 100 is arranged parallel to the planar portion, and the circuit layer 120 is electrically connected to the bonding area 13.

[0059] Because flexible display panels have the ability to be bent repeatedly, the bent parts will fold during user use. Flexible display panels using this implementation structure circuit board can capture the transient strain waveform and amplitude of each folding action using the sensing unit 200. Combined with strain and electrical failure analysis models, the usage status and lifespan of the bent parts of the flexible display panel can be assessed in a timely manner.

[0060] Another aspect of the present invention provides a display module, which includes a display panel 300 and a circuit board 100 as described in any of the foregoing embodiments, wherein the circuit board 100 is electrically connected to the display panel 300.

[0061] In one application scenario, the display module can be as follows: Figure 4 The illustrated implementation shows a display module that is either a rigid display panel or a micro-curved screen display panel. In another application scenario, the display module can be, for example... Figure 21 The embodiment shown is a display module for a flexible display panel.

[0062] The specific implementation structure of the display module using this circuit board 100 can be combined with the above. Figures 1 to 21 The detailed description will not be repeated here.

[0063] One embodiment of the present invention also provides an electronic device, which includes the display module of any of the foregoing embodiments. In this embodiment, the display module integrated within the electronic device inherits the in-situ strain monitoring and electrical failure diagnosis capabilities of the circuit board. In actual products, the electronic device may also include conventional components such as a processor, memory, battery, communication module, camera assembly, and housing. These components work in conjunction with the display module to achieve complete electronic functions. Optionally, the electronic device may be any portable or fixed terminal equipped with a display function, such as a smartphone, tablet computer, laptop computer, smartwatch, virtual reality (VR) headset, in-vehicle display, or medical monitor.

[0064] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0065] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A circuit board, characterized in that, include: A substrate and a circuit layer disposed on the substrate; wherein the substrate includes a strain detection layer, the strain detection layer being insulated from and stacked with the circuit layer; and a plurality of sensing units arranged in an array are disposed on the strain detection layer. An interlayer conductive structure extends through the insulation region between the strain detection layer and the circuit layer, and multiple sensing units are electrically connected to the circuit layer through the interlayer conductive structure.

2. The circuit board according to claim 1, characterized in that, The substrate further includes a substrate layer stacked with the strain detection layer, wherein the strain detection layer is disposed on the side of the substrate layer opposite to the circuit layer.

3. The circuit board according to claim 2, characterized in that, The substrate layer is a flexible material layer.

4. The circuit board according to claim 1, characterized in that, The strain detection layer is wrapped with an insulating protective layer, and the strain detection layer and the outer insulating protective layer are combined to form the substrate.

5. The circuit board according to claim 1, characterized in that, In a plurality of sensing units, each of the sensing units includes a plurality of sub-units, which are respectively disposed in different regions. Each of the sub-units includes sensing lines arranged in a serpentine pattern, and the sensing lines of the plurality of sub-units of a sensing unit are interconnected.

6. The circuit board according to claim 5, characterized in that, In a plurality of sub-units of the sensing unit, the sensing circuit includes parallel sub-circuits, which are any of the following: curved, horizontal, vertical, and inclined relative to the horizontal.

7. The circuit board according to claim 1, characterized in that, A conductive contact pad is provided on the circuit layer, and the sensing unit is connected to the conductive contact pad through the interlayer conductive structure; and / or, a first functional circuit is provided on the circuit layer, and the sensing unit is connected to the first functional circuit through the interlayer conductive structure.

8. The circuit board according to claim 7, characterized in that, The first functional circuit includes IC chip power supply lines and / or IC chip redundant pin lines.

9. The circuit board according to claim 1 or 7, characterized in that, The substrate includes at least two mutually insulated and stacked strain detection layers, and the sensing unit of each strain detection layer is electrically connected to the circuit layer through different interlayer conduction structures.

10. The circuit board according to claim 1, characterized in that, Multiple sensing units are arranged in an array along the row and column directions. Multiple sensing units in each row are connected by a walk line, and multiple sensing units in each column are connected by a column walk line. The walk lines and column walk lines are insulated from each other.

11. The circuit board according to claim 10, characterized in that, Each walking line and each column line is connected in series with a switching element. One or more walking lines are connected to a signal input terminal, and one or more column lines are connected to a signal acquisition terminal.

12. The circuit board according to claim 1, characterized in that, The circuit layer includes a strain detection circuit, and multiple sensing units are connected to the strain detection circuit through the interlayer conduction structure.

13. The circuit board according to claim 1, characterized in that, The interlayer conductive structure includes vertical through holes.

14. A display module, characterized in that, include: Display panel; as well as The circuit board as described in any one of claims 1 to 13, wherein the circuit board is electrically connected to the display panel.

15. The display module according to claim 14, characterized in that, The display panel includes a bonding area disposed on a first end face, the first end face being the display surface of the display panel. The display module further includes a printed circuit board assembly (PCBA) component disposed on a second end face of the display panel facing away from the first end face. The circuit board is in a bent state, and the PCBA component and the bonding area are electrically connected to the circuit layer, respectively.

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