Display module and display device

Abstract

This disclosure provides a display module and display device, relating to the field of display technology. The display module includes: a display panel comprising a plurality of panel partitions sequentially distributed along a first direction and fold lines located between adjacent panel partitions, the fold lines extending along a second direction; each panel partition including a flat area and a bent area connected to the flat area; the first and second directions intersect; and a flexible circuit board comprising a plurality of first plates corresponding one-to-one with each bent area and a second plate connecting adjacent first plates; the bent areas are electrically connected to the corresponding first plates; the first plates are provided with traces; the orthographic projection of the extension line of the fold line along the second direction onto the flat area overlaps with the orthographic projection of the second plate onto the flat area; the second plate is flexible; wherein the flexible circuit board can be bent to the back of the display panel through the bent areas, improving reliability.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and more specifically, to a display module and a display device. Background Technology

[0002] With the rapid development of foldable display technology, large-size foldable display devices are becoming increasingly popular among consumers due to their combination of portability and wide viewing angle.

[0003] In existing foldable display modules, due to the presence of metal traces in the flexible circuit board, the overall wiring structure of the flexible circuit board is difficult to adapt to the partitioned folding layout of the display panel. The folding line area is prone to trace breakage, affecting reliability.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] This disclosure provides a display module and display device that can improve the reliability of the display module.

[0006] According to one aspect of this disclosure, a display module is provided, comprising: The display panel includes a plurality of panel partitions distributed sequentially along a first direction and a fold line located between two adjacent panel partitions. The fold line extends along a second direction. Each panel partition includes a flat area and a bent area connected to the flat area. The first direction and the second direction intersect. A flexible circuit board includes a plurality of first plates corresponding one-to-one with each of the bending areas and a second plate connecting two adjacent first plates. The bending areas are electrically connected to the corresponding first plates. The first plates are provided with traces. The orthographic projection of the extension line of the fold line along the second direction on the straight area overlaps with the orthographic projection of the second plate on the straight area. The second plate is flexible. The flexible circuit board can be bent to the back of the display panel through the bending area.

[0007] In one embodiment of this disclosure, the first plate includes a flexible layer and a composite layer located on at least one side of the flexible layer; The flexible layer and the second plate are the same film layer; the composite layer includes a wiring layer, a cover layer and an electromagnetic shielding layer stacked on the flexible layer in a direction away from the flexible layer, and the wiring layer has a plurality of the wirings.

[0008] In one embodiment of this disclosure, the second plate has a hollow structure, and the orthographic projection of the extension line of the fold line along the second direction on the straight area overlaps with the orthographic projection of the hollow structure on the straight area.

[0009] In one embodiment of this disclosure, the flexible circuit board further includes an adhesive layer, which is disposed at the junction of the first board body and the second board body and covers the end faces of the wiring layer, the cover layer, and the electromagnetic shielding layer.

[0010] In one embodiment of this disclosure, the flexible circuit board further includes a first connector disposed on the first board body, the first connector being electrically connected to the wiring layer; in two adjacent first boards bodies, the two first connectors are electrically connected through flexible leads.

[0011] In one embodiment of this disclosure, the first board body has a first bonding area at one end near the bending area, the first bonding area has a first pad, and the first bonding area has a first alignment mark at both ends along the first direction. The bending area has a second bonding area at one end away from the display panel. The second bonding area has a second pad that is bonded to the first pad. The bending area has a second alignment mark at both ends along the first direction that corresponds to the first alignment mark. The orthographic projection of the first alignment mark on the flat area overlaps with the orthographic projection of the corresponding second alignment mark on the flat area.

[0012] In one embodiment of this disclosure, the flexible circuit board has a support film before bending in the bending area, the support film exposing the first bonding area and covering the second board body, and a gap between the support film and the second board body.

[0013] In one embodiment of this disclosure, the straight area has a third alignment mark, and the bending area has a fourth alignment mark that corresponds one-to-one with the third alignment mark. After the bending area is bent, the orthographic projection of the third alignment mark on the straight area and the orthographic projection of the corresponding fourth alignment mark on the straight area are at a specified distance.

[0014] In one embodiment of this disclosure, each of the bending areas is provided with a driving chip, and one of the driving chips is used to drive a flat area to display a screen.

[0015] According to another aspect of this disclosure, a display device is provided, comprising the display module described in any of the above embodiments.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0018] Figure 1 This is a front view of the display module in one embodiment of the present disclosure, intended to show the state in which the flexible circuit board is not bent to the back of the display panel.

[0019] Figure 2 for Figure 1 The diagram shows the front view of the display panel in the display module shown.

[0020] Figure 3 for Figure 1 The diagram shows a flexible circuit board in the display module.

[0021] Figure 4 for Figure 3 The diagram shows a schematic of the film layers on the flexible circuit board.

[0022] Figure 5 This is a schematic diagram of a flexible circuit board in one embodiment of the present disclosure, intended to illustrate a hollow structure.

[0023] Figure 6 This is a schematic diagram of the film layer of a flexible circuit board in one embodiment of the present disclosure, intended to illustrate the support film when the flexible circuit board is not bent to the back of the display panel.

[0024] Figure 7 This is a front view of the display panel in one embodiment of the present disclosure.

[0025] Figure 8 This is a schematic diagram of the film layers of a display panel in one embodiment of this disclosure.

[0026] Figure 9 This is a schematic diagram of the back of a display module in one embodiment of the present disclosure, intended to illustrate the state in which the flexible circuit board is bent to the back of the display panel.

[0027] Figure 10 This is a schematic diagram of the film layers of a display module in one embodiment of the present disclosure, intended to illustrate the state in which the flexible circuit board is bent to the back of the display panel.

[0028] Figure 11This is a schematic diagram of the back of a display module in one embodiment of the present disclosure, intended to illustrate the state in which the flexible circuit board is bent to the back of the display panel. Detailed Implementation

[0029] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.

[0030] Although relative terms such as "up" and "down" are used in this specification to describe the relative relationship of one component of an icon to another, these terms are used only for convenience, such as according to the orientation of the examples shown in the accompanying drawings. It is understood that if the device of the icon is flipped upside down, the component described as "up" will become the component described as "down." When a structure is "up" of another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" mounted on the other structure, or that the structure is "indirectly" mounted on the other structure through another structure.

[0031] The terms “a,” “one,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first,” “second,” and “third,” etc., are used only as markers and are not a limitation on the number of objects.

[0032] In this paper, structural layer A is located on the side of structural layer B away from the substrate. This can be understood as structural layer A being formed on the side of structural layer B away from the substrate. When structural layer B is a patterned structure, some structures of structural layer A may also be located at the same physical height as structural layer B or below the physical height of structural layer B, wherein the substrate serves as the height reference.

[0033] In this disclosure, a transistor is a device that includes at least three terminals: a gate electrode, a drain electrode, and a source electrode. The transistor has a channel region between the drain electrode (drain electrode terminal, drain region, or drain electrode) and the source electrode (source electrode terminal, source region, or source electrode), and current can flow through the drain electrode, the channel region, and the source electrode. The channel region refers to the region through which current primarily flows.

[0034] In this embodiment of the disclosure, the first direction DH and the second direction DV intersect, for example, the first direction DH and the second direction DV are perpendicular. The "thickness" of the film layer refers to the dimension of the film layer along a direction perpendicular to the plane formed by the first direction DH and the second direction DV.

[0035] This disclosure provides a display module. See also: Figure 1 , Figure 2 The display module includes a display panel (PNL) and a flexible circuit board (FPC). The display panel (PNL) includes multiple panel partitions (SP) sequentially distributed along a first direction (DH) and folding lines (CR) located between adjacent panel partitions (SP). The folding lines (CR) extend along a second direction (DV) to allow the display panel (PNL) to fold along the folding lines (CR). Each panel partition (SP) includes a flat area (SA) and a bent area (BA) connected to each flat area (SA). The flexible circuit board (FPC) includes multiple first boards (FP1) corresponding to each bent area (BA) and second boards (FP2) connecting adjacent first boards (FP1). The first boards (FP1) have traces. The bent areas (BA) are electrically connected to their corresponding first boards (FP1). The orthographic projection of the extension of the folding line (CR) along the second direction (DV) onto the flat area (SA) overlaps with the orthographic projection of the second board (FP2) onto the flat area (SA). The orthographic projection of the extension of the folding line (CR) along the second direction (DV) onto the flat area (SA) does not overlap with the orthographic projection of the first board (FP1) onto the flat area (SA). The second board (FP2) is flexible, meaning it does not have traces. (See also...) Figure 9 , Figure 10 The flexible printed circuit board (FPC) can be bent to the back of the display panel (PNL) through the bending area (BA).

[0036] In one example, see Figure 1 , Figure 2 The display panel PNL includes two panel partitions SP distributed sequentially along the first direction DH. Each panel partition SP includes a flat area SA and a bent area BA bound to the flat area SA. The ends of the two bent areas BA away from the flat area SA are respectively bound to a first plate body FP1. In another example, the number of panel partitions SP can be three, four, five, etc., without specific limitation, and can be set according to specific needs.

[0037] In this way, bending the flexible circuit board (FPC) to the back of the display panel (PNL) via the bending area BA facilitates a narrow bezel design for the display module, increasing the screen-to-body ratio. With traces on the first board FP1 and no traces on the second board FP2, the second board FP2, due to its flexibility, can synchronously complete the bending action along the folding line CR when the display panel PNL is folded. This avoids fatigue fracture of the traces on the second board FP2 due to folding, thus improving the reliability of the display module. Simultaneously, multiple first boards FP1 are electrically connected to their corresponding bending areas BA, allowing the overall structure of the flexible circuit board (FPC) to adapt to the folding shape of the multi-section folding display panel PNL, improving the overall bending reliability of the flexible circuit board (FPC). Furthermore, by connecting two adjacent first boards FP1 through the second board FP2, multiple first boards FP1 become a whole, avoiding problems such as bending, sagging, offset, and wrinkling of the pads on multiple first boards FP1. This allows the bonding equipment to bond multiple first boards FP1 of the flexible circuit board FPC to the bending area BA at one time, and the bending equipment to bend the entire flexible circuit board FPC to the back of the display panel PNL at one time. This avoids poor bonding and bending, improves production efficiency, and is conducive to mass production.

[0038] It should be noted that existing flexible circuit board bonding and bending equipment can only process one flexible circuit board at a time. After processing one flexible circuit board, the same equipment cannot directly process another flexible circuit board without readjusting the parameters, resulting in reduced production efficiency. The flexible circuit board (FPC) in this embodiment connects multiple first boards (FP1) into a single unit via second boards (FP2). Existing bonding and bending equipment can be used to process the flexible circuit board FPC of the folding display module in one go, eliminating the need to adjust the parameters of the bonding and bending equipment after processing one first board (FP1) before processing another first board (FP1) of the same display module, thus improving production efficiency.

[0039] It should also be noted that the display panel PNL has a front and a back. The front refers to the side of the display panel PNL that displays the image, and the back refers to the side of the display panel PNL that does not display the image.

[0040] It should also be noted that there is a folded area between two adjacent panel partitions SP, and the folded line CR is a line segment located within the folded area.

[0041] In one embodiment of this disclosure, the material of the second plate FP2 may include one or more of the following: polyimide, polyester film, polyethylene naphthalate, etc. The thickness of the second plate FP2 is 25 μm to 100 μm; for example, the thickness of the second plate FP2 may be 25 μm, 35 μm, 45 μm, 55 μm, 65 μm, 75 μm, 85 μm, 95 μm, or 100 μm.

[0042] In one embodiment of this disclosure, see Figure 2 The display panel PNL, in its unfolded state, has a long side and a short side. The long side extends along a first direction DH, and the short side extends along a second direction DV. The bending area BA and the flexible circuit board FPC are located on the long side of the display panel PNL. Each bending area BA is bound with a driver chip DIC. One driver chip DIC is used to apply data voltage to a flat area SA to drive the display screen of that flat area SA. In this way, by configuring one driver chip DIC to drive the display screen of each flat area SA, the signals of each flat area SA are independent, and the display brightness, refresh rate, and screen color can be controlled separately, effectively improving the problems of uneven display and screen tearing in the fold line CR area. At the same time, the load of a single driver chip DIC is smaller, and the drive response is faster, which is beneficial to improving the overall display effect and drive stability. In addition, placing the driver chip DIC on the long side of the display panel PNL makes the display panel PNL suitable for high refresh rate scenarios (such as gaming scenarios, VR scenarios, etc.).

[0043] In one embodiment of this disclosure, see Figure 7 The display panel PNL includes a display area AA and a peripheral area BB located on at least one side of the display area AA. The display area AA of the display panel PNL includes an array of display units. Each display unit includes a sub-pixel PIX and a pixel driving circuit PDC that drives the sub-pixel PIX. The display panel PNL has multiple scan lines GL arranged along a first direction DH in the display area AA, each scan line GL corresponding to a row of display units; each scan line GL is connected to a pixel driving circuit PDC in the corresponding row of display units. The display panel PNL also has multiple data lines DL arranged along a second direction DV in the display area AA, each data line DL corresponding to a column of display units; each data line DL is connected to a pixel driving circuit PDC in the corresponding column of display units. Thus, each pixel driving circuit PDC of a display unit is connected to one scan line GL and one data line DL. When a strobe signal is applied to the scan line GL, the data voltage applied to the data line DL can be applied to the pixel driving circuit PDC, allowing the pixel driving circuit PDC to control the brightness of the sub-pixel PIX based on the written data voltage.

[0044] It should be noted that each flat area SA includes a display sub-area and a peripheral sub-area located on the side of the display sub-area. All display sub-areas together form the display area AA of the display panel PNL, and all peripheral sub-areas together form the peripheral area BB of the display panel PNL. The curved area BA is bound and connected to the peripheral sub-area of ​​the flat area SA.

[0045] Optionally, the sub-pixel PIX can be a current-driven self-emissive element, such as any one of OLED, PLED, QLED, Micro LED, Mini LED, etc. In this embodiment, the sub-pixel PIX can include multiple sub-pixel PIXs of different colors, such as a red sub-pixel for emitting red light, a green sub-pixel for emitting green light, and a blue sub-pixel for emitting blue light. It is understood that in other embodiments of this disclosure, the sub-pixel PIX in the display area AA can also have sub-pixel PIXs of other colors (e.g., a yellow sub-pixel for emitting yellow light, a cyan sub-pixel for emitting cyan light, a white sub-pixel for emitting white light, etc.).

[0046] In one embodiment of this disclosure, see Figure 8 The display panel PNL may include a driving backplane BP and a pixel layer PIXL stacked sequentially. The driving backplane BP may include a substrate SBT and a driving layer DRL stacked on the substrate SBT. The pixel layer PIXL contains sub-pixels PIX, and the driving layer DRL contains a pixel driving circuit PDC for driving the sub-pixels PIX; each sub-pixel PIX can emit light under the drive of the pixel driving circuit PDC to display an image. Furthermore, the display panel PNL also includes a thin-film encapsulation layer TFE located on the side of the pixel layer PIXL away from the substrate SBT, which encapsulates and protects the pixel layer PIXL.

[0047] Optionally, the substrate SBT can be an inorganic material substrate or an organic material substrate; of course, it can also be a composite substrate formed by stacking inorganic and organic material substrates. For example, in some embodiments of this disclosure, the material of the substrate SBT can be glass materials such as soda-lime glass, quartz glass, and sapphire glass. In other embodiments of this disclosure, the material of the substrate SBT can be polymethyl methacrylate, polyvinyl alcohol, polyvinylphenol, polyethersulfone, polyimide, polyamide, polyacetal, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, or combinations thereof.

[0048] Optionally, in the driving layer DRL, any pixel driving circuit PDC may include a thin-film transistor (TFT) and a storage capacitor. Further, the TFT can be selected from top-gate, bottom-gate, or dual-gate TFTs; the active layer of the TFT can be made of amorphous silicon semiconductor, low-temperature polycrystalline silicon semiconductor, metal-oxide semiconductor, organic semiconductor, carbon nanotube semiconductor, or other types of semiconductor materials; the TFT can be an N-type or P-type TFT.

[0049] It is understood that any two transistors in a pixel driver circuit (PDC) can be of the same or different types. Exemplarily, in some embodiments, some transistors in a PDC can be N-type transistors and some transistors can be P-type transistors. Further exemplarily, in other embodiments, in a PDC, the active layer material of some transistors can be low-temperature polycrystalline silicon (LTPS) semiconductor material, and the active layer material of some transistors can be metal-oxide-semiconductor (MODS) semiconductor material. In some embodiments of this disclosure, the thin-film transistor is a LPS transistor. In other embodiments of this disclosure, some thin-film transistors are LPS transistors, and some thin-film transistors are MODS transistors.

[0050] Optionally, the driving layer DRL may include a semiconductor layer SCL, a gate insulating layer GI, a gate layer GT, an interlayer dielectric layer ILD, a source / drain metal layer SD, a planarization layer PLN, etc., stacked between the substrate SBT and the pixel layer PIXL. Each thin-film transistor and storage capacitor may be located within the semiconductor layer SCL, gate insulating layer GI, gate layer GT, interlayer dielectric layer ILD, source / drain metal layer SD, etc. The positional relationship of each layer can be determined based on the thin-film transistor's layer structure. Further, the semiconductor layer SCL can be used to form the channel region of the transistor, and may also be used to form partial traces or conductive structures by conductiveing ​​if necessary. The gate layer GT can be used to form one or more of the following gate layer GT traces: write control traces, reset control traces, light emission control traces, etc., or it can be used to form the gate of the transistor, or it can be used to form part or all of the electrode plates of the storage capacitor. The source / drain metal layer SD can be used to form data traces, drive power supply voltage traces, etc., or it can be used to form part of the electrode plates of the storage capacitor. Of course, in other embodiments of this disclosure, the driving layer DRL may also include other film layers as needed, such as a light-shielding layer located between the semiconductor layer SCL and the substrate SBT. As needed, any one of the above-mentioned semiconductor layer SCL, gate layer GT, source / drain metal layer SD may be multiple layers. For example, the driving layer DRL may include two different semiconductor layers SCL, or two or three source / drain metal layers SD, or two or three gate layers GT. Correspondingly, the insulating film layers in the driving layer DRL (such as gate insulating layer GI, interlayer dielectric layer ILD, planarization layer PLN, etc.) may be increased or decreased adaptively, or new insulating film layers may be added as needed.

[0051] Optionally, the driving layer DRL may also include a passivation layer, which may be disposed on the surface of the source / drain metal layer SD away from the substrate SBT, in order to protect the source / drain metal layer SD.

[0052] As an example, see Figure 8 The driving layer DRL may include a buffer layer Buff, a semiconductor layer SCL, a gate insulating layer GI, a gate layer GT, an interlayer dielectric layer ILD, a source / drain metal layer SD, and a planarization layer PLN stacked sequentially. The thin film transistor formed in this way is a top-gate thin film transistor.

[0053] In one embodiment of this disclosure, the sub-pixel PIX in the pixel layer PIXL is a thin-film light-emitting element, which may include two stacked electrodes and a light-emitting functional unit sandwiched between the two electrodes. For example, see... Figure 8The pixel layer PIXL may include a light-emitting element layer PEL, a light-emitting functional layer EFL, and a common electrode layer COML stacked sequentially. The light-emitting element layer PEL has multiple light-emitting elements PE in the display area of ​​the display panel; the portion of the light-emitting functional layer EFL connected to the light-emitting elements PE serves as the light-emitting functional unit of the sub-pixel PIX; and the common electrode layer COML serves as a common electrode electrically connected to the light-emitting functional units of each sub-pixel PIX.

[0054] Furthermore, the pixel layer PIXL may also include a pixel definition layer PDL located between the light-emitting element layer PEL and the light-emitting functional layer EFL. The pixel definition layer PDL has multiple through-hole pixel openings corresponding one-to-one with multiple light-emitting elements PE, with each pixel opening exposing at least a portion of the corresponding light-emitting element. For example, the pixel definition layer PDL covers the edge of the light-emitting element PE and exposes at least a portion of the internal region of the light-emitting element PE, so that the pixel definition layer PDL can effectively define the actual effective area of ​​the light-emitting element PE (the area directly connected to the light-emitting functional unit), thereby defining the light-emitting area and light-emitting region of the sub-pixel PIX. The light-emitting functional layer EFL at least covers the light-emitting element PE exposed by the pixel definition layer PDL. The common electrode layer COML may cover the light-emitting functional layer EFL in the display area. The light-emitting elements PE and the common electrode layer COML provide charge carriers such as electrons and holes to the light-emitting functional layer EFL, causing the light-emitting functional layer EFL to emit light. The portion of the light-emitting functional layer EFL located between the light-emitting element layer PEL and the common electrode layer COML can serve as a light-emitting functional unit. The light-emitting elements PE, the common electrode layer COML, and the light-emitting functional unit form the sub-pixel PIX. In this design, one of the light-emitting element PE and the common electrode layer COML serves as the anode of the sub-pixel PIX, and the other serves as the cathode of the sub-pixel PIX.

[0055] In one example, the light-emitting element PE serves as the anode of the sub-pixel PIX, which can be electrically connected to the flexible circuit board FPC via wires, and the common electrode layer COML serves as the cathode of the sub-pixel PIX.

[0056] Understandably, different types of light-emitting elements result in different materials and film layers for the light-emitting functional units. For example, when the light-emitting element is an OLED, the light-emitting functional unit may include an organic electroluminescent material layer, and may include one or more of the following: a hole injection layer, a hole transport layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0057] See Figure 8The thin-film encapsulation layer TFE can be disposed on the surface of the pixel layer PIXL away from the substrate SBT, and it can include alternately stacked inorganic encapsulation layers and organic encapsulation layers. The inorganic encapsulation layer can effectively block external moisture and oxygen, preventing water and oxygen from invading the pixel layer PIXL and causing material aging in the pixel layer PIXL. Optionally, the edge of the inorganic encapsulation layer can be located in the peripheral area. The organic encapsulation layer is located between two adjacent inorganic encapsulation layers to achieve planarization and reduce stress between the inorganic encapsulation layers. The edge of the organic encapsulation layer can be located between the edge of the display area and the edge of the inorganic encapsulation layer. For example, the thin-film encapsulation layer TFE includes a first inorganic encapsulation layer CVD1, an organic encapsulation layer IJP, and a second inorganic encapsulation layer CVD2 stacked sequentially on the side of the pixel layer PIXL away from the substrate SBT. The first inorganic encapsulation layer CVD1 covers the display area and extends to the outside of the barrier; the organic encapsulation layer covers the display area and extends to the inside of the barrier; the second inorganic encapsulation layer CVD2 covers the organic encapsulation layer IJP and extends to the outside of the barrier. On the outside of the retaining wall, the second inorganic encapsulation layer CVD2 is in contact with the first inorganic encapsulation layer CVD1. In this way, the organic encapsulation layer IJP is sealed by the first inorganic encapsulation layer CVD1 and the second inorganic encapsulation layer CVD2, balancing the stress in the first inorganic encapsulation layer CVD1 and the second inorganic encapsulation layer CVD2. The first inorganic encapsulation layer CVD1 and the second inorganic encapsulation layer CVD2 seal the organic encapsulation layer IJP, preventing the organic encapsulation layer IJP from contacting water and oxygen.

[0058] In some embodiments of this disclosure, see Figure 8 The display panel PNL may also include a touch function layer TSL, which may be disposed on the side of the thin film encapsulation layer TFE away from the driving backplane DBP, so that the display panel PNL has touch function.

[0059] Optionally, the pixel driving circuit PDC includes at least a data writing transistor, a driving transistor, and a storage capacitor. The gate of the driving transistor can be electrically connected to one electrode plate of the storage capacitor. The source of the data writing transistor can be electrically connected to the data line DL, and the gate of the data writing transistor can be electrically connected to the scan line GL. The pixel driving circuit PDC is configured such that when a scan signal is applied to the scan line GL, the data writing transistor is turned on, thereby causing the data voltage on the data line DL to be written to the gate of the driving transistor and the storage capacitor. When the data writing transistor is turned off, the data voltage can be maintained by the storage capacitor. The driving transistor can output a driving current to drive the sub-pixel PIX to emit light under the control of the voltage on its gate. It is understood that the pixel driving circuit PDC of this disclosure embodiment may also include other transistors or capacitors to give the pixel driving circuit PDC better driving performance. For example, the pixel driving circuit PDC can be a 7T1C (7 thin film transistors and one storage capacitor), an 8T1C (8 thin film transistors and one storage capacitor), or a pixel driving circuit with other architectures.

[0060] In one embodiment of this disclosure, see Figure 3 , Figure 4 The first plate FP1 includes a flexible layer SL and a composite layer FL located on at least one side of the flexible layer SL. The flexible layer SL and the second plate FP2 share the same film layer, meaning the flexible layer SL is also a flexible substrate. The composite layer FL includes a trace layer ZL, a cover layer CL, and an electromagnetic shielding layer EML stacked on the flexible layer SL in a direction away from the flexible layer SL. The trace layer ZL has multiple traces. In other words, the composite layer FL is peeled off in the second plate FP2. Thus, by ensuring that the flexible layer SL and the second plate FP2 share the same film layer, the structural continuity between the first plate FP1 and the second plate FP2 is maintained, reducing process complexity and improving overall flatness and structural strength. Simultaneously, within the composite layer FL, the trace layer ZL provides signal and power supply trace routing, the cover layer CL provides insulation protection for the trace layer ZL, and the electromagnetic shielding layer EML provides electromagnetic shielding, effectively suppressing electromagnetic interference and improving signal transmission stability.

[0061] In one example, the number of composite layers FL is one, so that the flexible circuit board FPC is a single-sided structure.

[0062] In another example, see Figure 4 There are two composite layers FL, which are respectively located on both sides of the flexible layer SL, so that the flexible circuit board FPC has a double-sided structure.

[0063] In one embodiment of this disclosure, the wiring layer ZL can be made of conductive metals such as copper, silver, aluminum, and gold; the cover layer CL can be made of materials such as polyimide, polyester film, polyethylene naphthalate, and epoxy resin; and the electromagnetic shielding layer EML can be made of materials such as copper, aluminum, graphite, and conductive cloth.

[0064] In one embodiment of this disclosure, see Figure 5 , Figure 11 The second plate FP2 has a hollow structure LK, which includes multiple spaced through holes. These through holes can be fabricated using laser drilling. The orthographic projection of the extension of the fold line CR along the second direction DV onto the straight region SA overlaps with the orthographic projection of the hollow structure LK onto the straight region SA. Thus, by incorporating the hollow structure LK into the second plate FP2, the hollow structure LK can further release the folding stress at the fold line CR, reduce the tensile and compressive deformation of the second plate FP2 during folding, lower the risk of breakage, and improve the folding resistance and service life of the second plate FP2.

[0065] In one embodiment of this disclosure, along the first direction DH, the distance between the orthographic projection of the extension line of the folding line CR onto the flat area SA and the orthographic projection of the first plate FP1 onto the flat area SA is not less than 2 mm. For example, the distance between the orthographic projection of the extension line of the folding line CR onto the flat area SA and the orthographic projection of the first plate FP1 onto the flat area SA can be 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, etc. In other words, the length of the second plate FP2 along the first direction DH is not less than 2 mm, so that the second plate FP2 has a suitable folding area, realizing the folding of the second plate FP2 with the display panel PNL.

[0066] In one embodiment of this disclosure, see Figure 3 , Figure 4The flexible printed circuit board (FPC) also includes an adhesive layer AL. The adhesive layer AL is located at the junction of the first board FP1 and the second board FP2, and covers the end faces of the trace layer ZL, the cover layer CL, and the electromagnetic shielding layer EML. The end faces of the trace layer ZL, the cover layer CL, and the electromagnetic shielding layer EML refer to the edge surfaces on the second board FP2 that are cut off when the trace layer ZL, the cover layer CL, and the electromagnetic shielding layer EML are located at the junction of the first board FP1 and the second board FP2. When composite layers FL are provided on both sides of the flexible layer SL, the adhesive layer AL is also provided on both sides of the flexible layer SL. The length of the adhesive layer AL along the first direction DH is not less than 30 μm; for example, the length of the adhesive layer AL along the first direction DH can be 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, etc. The length of the adhesive layer AL along the second direction DV is not less than 300μm. For example, the length of the adhesive layer AL along the second direction DV can be 300μm, 305μm, 310μm, 315μm, 320μm, etc. In this way, the adhesive layer AL can seal and protect the end faces of the multilayer structure of the composite layer FL, preventing moisture and dust from entering the interlayer, preventing trace oxidation and interlayer short circuits in the trace layer ZL, and at the same time alleviating stress concentration at the junction of the first board FP1 and the second board FP2, thus improving the folding performance of the flexible circuit board FPC.

[0067] In one embodiment of this disclosure, see Figure 3 , Figure 4 , Figure 9 , Figure 11 The flexible printed circuit board (FPC) also includes a first connector BT1 disposed on the first board FP1. The first connector BT1 is electrically connected to the wiring layer ZL through a via. In two adjacent first boards FP1, the first connector BT1 is disposed at the end of the two first boards FP1 that is close to each other, and the two first connectors BT1 are electrically connected through a flexible lead RL. The flexible lead RL can be plugged into the first connector BT1. In this way, the two adjacent first connectors BT1 are electrically connected through the flexible lead RL to realize the electrical connection between the two adjacent first boards FP1, so that multiple first boards FP1 form a functional whole, eliminating the need for dense wiring on the first board FP1 and improving folding safety.

[0068] In one embodiment of this disclosure, see Figures 1-3The first board FP1 has a first bonding area PAD1 at the end near the bending area BA. The first bonding area PAD1 has a first pad. The two ends of the first bonding area PAD1 along the first direction DH have a first alignment mark MR1. The end of the bending area BA away from the display panel PNL has a second bonding area PAD2. The second bonding area PAD2 has a second pad that is bonded to the first pad. The two ends of the bending area BA along the first direction DH have a second alignment mark MR2 that corresponds to the first alignment mark MR1. The orthographic projection of the first alignment mark MR1 on the flat area SA overlaps with the orthographic projection of the corresponding second alignment mark MR2 on the flat area SA. Thus, when binding the first board FP1 to the bending area BA, the first alignment mark MR1 and the second alignment mark MR2 can be captured by a camera device (such as a CCD camera). The first alignment mark MR1 and the second alignment mark MR2 form a precise alignment reference, which improves the binding accuracy of the first pad of the first binding area PAD1 and the second pad of the second binding area PAD2, prevents misalignment from causing cold solder joints and open circuits, and improves the connection quality between the first board FP1 and the bending area BA.

[0069] In one example, see Figures 1-3 There are two bending areas BA and two first plates FP1. Correspondingly, each first plate FP1 has two first alignment marks MR1 ​​at both ends of the first binding area PAD1 along the first direction DH, and each bending area BA has two second alignment marks MR2. The four first alignment marks MR1 ​​are divided into the two outermost first alignment marks MR1 ​​and the two innermost first alignment marks MR1, and the four second alignment marks MR2 are divided into the two outermost second alignment marks MR2 and the two innermost second alignment marks MR2. When binding, the camera device can first grab the two outermost first alignment marks MR1 ​​and the two outermost second alignment marks MR2 on the flexible circuit board FPC and align them, and then grab the two innermost first alignment marks MR1 ​​and the two innermost second alignment marks MR2 and align them, so as to realize the binding connection between the bending area BA and the flexible circuit board FPC.

[0070] In one embodiment of this disclosure, see Figure 6The flexible printed circuit board (FPC) has a support film ZC before bending in the bending area BA. The support film ZC is made of a rigid material and is parallel to the plane formed by the first direction DH and the second direction DV. The support film ZC exposes the first bonding area PAD1 and covers the second board body FP2. There is a gap between the support film ZC and the second board body FP2. The thickness of the support film ZC is 0.05mm to 0.15mm, for example, the thickness of the support film ZC can be 0.05mm, 0.08mm, 0.11mm, 0.14mm or 0.15mm. After bending the flexible printed circuit board FPC to the back of the display panel PNL, the support film ZC is peeled off. Thus, the support film ZC can improve the flatness and support of the flexible circuit board FPC, making multiple first boards FP1 a highly supportive whole. During the bonding and bending processes of the flexible circuit board FPC, the support film ZC can provide a larger vacuum adsorption area for the suction cups of the bonding and bending equipment, which is beneficial for the bonding and bending of the flexible circuit board FPC to the back of the display panel PNL.

[0071] In one embodiment of this disclosure, see Figure 9 , Figure 11 The flat area SA has a third alignment mark MR3, and the bending area BA has a fourth alignment mark MR4 that corresponds one-to-one with the third alignment mark MR3. After the bending area BA is bent, the orthographic projection of the third alignment mark MR3 on the flat area SA and the orthographic projection of the corresponding fourth alignment mark MR4 on the flat area SA are at a specified distance. After the flexible circuit board (FPC) is bent to the back of the display panel PNL, the third alignment mark MR3 and the fourth alignment mark MR4 can be used as a reference for detecting and positioning the bending stroke and bending angle, accurately controlling the bending shape of the bending area BA, preventing excessive bending from damaging the panel and circuits, ensuring the consistency of each bending action, and improving the stability of the display module.

[0072] In one example, see Figure 9 , Figure 11There are two bending zones (BA) and two straight zones (SA). Correspondingly, there are two third alignment marks (MR3) on each straight zone (SA). The third alignment marks (MR3) are located in the outer sub-area of ​​the straight zone (SA). The third alignment marks (MR3) can be located on the back of the display panel (PNL). There are two fourth alignment marks (MR4) on each bending zone (BA). The four third alignment marks (MR3) are spaced apart along the first direction (DH), and the four fourth alignment marks (MR4) are spaced apart along the first direction (DH). During the bending process of the bending zone (BA), the camera device can first capture the two outermost third alignment marks (MR3) and the two outermost fourth alignment marks (MR4) for alignment, and then capture the two innermost third alignment marks (MR3) and the two innermost fourth alignment marks (MR4) for verification and correction to facilitate the bending of the bending zone (BA). When the flexible circuit board (FPC) is bent to the back of the display panel (PNL) through the bending zone (BA), there is a specified distance between the third alignment marks (MR3) and the corresponding fourth alignment marks (MR4). The specified distance can be set according to specific needs and is not specifically limited here.

[0073] Furthermore, on the same bending area BA, the driver chip DIC is located between two fourth alignment marks MR4 and is bent to the back of the display panel PNL.

[0074] In one embodiment of this disclosure, see Figure 3 , Figure 4 , Figure 9 , Figure 10 Each first board FP1 has a component EP. The component EP can be located on the side of the electromagnetic shielding layer EML away from the flexible layer SL, and is electrically connected to the traces of the trace layer ZL through vias. The component EP can include electronic components such as capacitors, resistors, and diodes. When the flexible circuit board FPC is bent to the back of the display panel PNL, the component EP is located on the side of the flexible circuit board FPC away from the flat area SA.

[0075] In one embodiment of this disclosure, see Figure 3 , Figure 4 One of the first plates FP1 has a protrusion extending along a first direction DH. The protrusion is provided with a second connector BT2 for electrical connection with the whole machine. The second connector BT2 and the component EP are located on the same side of the first plate FP1 to facilitate signal interaction between the flexible circuit board FPC and the whole machine.

[0076] In one embodiment of this disclosure, see Figure 6 The support membrane ZC also exposes the first connector BT1, component EP, and second connector BT2.

[0077] In one embodiment of this disclosure, see Figure 9 , Figure 10 The display module also includes a cover plate CG and a support plate BKT. The cover plate CG is positioned near the front of the display panel PNL, while the support plate BKT is located on the side of the flexible printed circuit board (FPC) away from the display panel PNL. Both the cover plate CG and the support plate BKT can be folded at the fold line CR. Thus, after the flexible printed circuit board (FPC) is bent to the back of the display panel PNL, it can be bonded to the support plate BKT using adhesive, providing support for the bent FPC.

[0078] This disclosure also provides a display device, including the display module and driving module described in any of the above embodiments. The driving module may include chips such as a timing controller and a power management chip to drive the display module to display an image. This display device can be a smartphone, tablet computer, laptop computer, automotive display, television, or other type of display device. This display device has the beneficial effects of the aforementioned display module, which will not be elaborated upon here.

[0079] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A display module, characterized by include: The display panel includes a plurality of panel partitions distributed sequentially along a first direction and a fold line located between two adjacent panel partitions. The fold line extends along a second direction. Each panel partition includes a flat area and a bent area connected to the flat area. The first direction and the second direction intersect. A flexible circuit board includes a plurality of first plates corresponding one-to-one with each of the bending areas and a second plate connecting two adjacent first plates. The bending areas are electrically connected to the corresponding first plates. The first plates are provided with traces. The orthographic projection of the extension line of the fold line along the second direction on the straight area overlaps with the orthographic projection of the second plate on the straight area. The second plate is flexible. The flexible circuit board can be bent to the back of the display panel through the bending area.

2. The display module of claim 1, wherein, The first plate includes a flexible layer and a composite layer located on at least one side of the flexible layer; The flexible layer and the second plate are the same film layer; the composite layer includes a wiring layer, a cover layer and an electromagnetic shielding layer stacked on the flexible layer in a direction away from the flexible layer, and the wiring layer has a plurality of the wirings.

3. The display module of claim 2, wherein, The second plate has a hollow structure, and the orthographic projection of the extension line of the fold line along the second direction on the flat area overlaps with the orthographic projection of the hollow structure on the flat area.

4. The display module of claim 2, wherein, The flexible circuit board further includes an adhesive layer, which is disposed at the junction of the first board body and the second board body and covers the end faces of the wiring layer, the cover layer and the electromagnetic shielding layer.

5. The display module according to claim 2, characterized in that, The flexible circuit board further includes a first connector disposed on the first board body, the first connector being electrically connected to the wiring layer; in two adjacent first boards bodies, the two first connectors are electrically connected through flexible leads.

6. The display module of claim 1, wherein, The first plate has a first bonding area at one end near the bending area, the first bonding area has a first pad, and the first bonding area has a first alignment mark at both ends along the first direction; The bending area has a second bonding area at one end away from the display panel. The second bonding area has a second pad that is bonded to the first pad. The bending area has a second alignment mark at both ends along the first direction that corresponds to the first alignment mark. The orthographic projection of the first alignment mark on the flat area overlaps with the orthographic projection of the corresponding second alignment mark on the flat area.

7. The display module of claim 6, wherein, The flexible circuit board has a support film before bending in the bending area. The support film exposes the first bonding area and covers the second board body, and there is a gap between the support film and the second board body.

8. The display module of claim 1, wherein, The straight area has a third alignment mark, and the bending area has a fourth alignment mark that corresponds one-to-one with the third alignment mark. After the bending area is bent, the orthographic projection of the third alignment mark on the straight area and the orthographic projection of the corresponding fourth alignment mark on the straight area are at a specified distance.

9. The display module of any one of claims 1-8, wherein, Each of the bending areas is equipped with a driving chip, and one of the driving chips is used to drive the display screen of one of the straight areas.

10. A display device, characterized by comprising: Includes the display module as described in any one of claims 1 to 9.

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