Display panel and manufacturing method thereof, display device and tiled display device

Abstract

The invention discloses a display panel and a manufacturing method thereof, a display device and a tiled display device, and belongs to the technical field of display. The display panel comprises a substrate, a bridging structure, a filling structure, a buffer structure and a plurality of side wires. In the display panel, a corner region exists between a second side surface of a bridge structure and a second surface of a substrate, and a filling structure may be located between a buffer structure and the corner region to reduce a gap between the buffer structure and the corner region. In this way, bubbles in the buffer structure can be reduced, the flatness of the buffer surface of the buffer structure is improved, and the side wiring on the buffer structure is prevented from being disconnected.

Description

Technical Field

[0001] The present application relates to the field of display technologies, and particularly to a display panel, a manufacturing method thereof, a display device, and a tiled display device. Background Art

[0002] A display panel is a device with a display function.

[0003] A display panel includes a substrate, a bridge structure (English: Bridge), a buffer structure, and side traces. The bridge structure and the buffer structure are disposed on the back surface of the substrate (the substrate includes a front surface, a back surface, and side surfaces, the front surface and the back surface are oppositely disposed, and the side surfaces are respectively connected to the front surface and the back surface), and at least a part of the side traces is located on at least one side surface of the substrate. Among them, the buffer structure is located on one side of the bridge structure close to the target side surface of the substrate, the target side surface is the side surface provided with the side traces, one end of the side traces is located on the surface of the bridge structure facing away from the substrate, and the other end extends to the front surface of the substrate through the buffer structure, the back surface of the substrate, and the side surface of the substrate in sequence. The buffer structure can reduce the influence of the step difference between the surface of the bridge structure facing away from the substrate and the back surface of the substrate on the side traces.

[0004] However, in the above display panel, the flatness of the surface of the buffer structure is poor, resulting in the side traces formed on the buffer structure being prone to open circuit, and thus the yield of the display panel is low. Summary of the Invention

[0005] Embodiments of the present application provide a display panel, a manufacturing method thereof, a display device, and a tiled display device. The technical solutions are as follows:

[0006] According to one aspect of the present application, a display panel is provided, and the display panel includes:

[0007] A substrate, including opposite first and second surfaces, and a plurality of first side surfaces connecting the first surface and the second surface, the first surface including a display area, and the plurality of first side surfaces including at least one target first side surface;

[0008] A bridge structure, disposed on the second surface, the bridge structure including opposite third and fourth surfaces, and a plurality of second side surfaces connecting the third surface and the fourth surface, the third surface being located on the side of the fourth surface close to the substrate, the plurality of second side surfaces including at least one target second side surface, each target second side surface corresponding to a target first side surface, and the target second side surface having the same orientation as the corresponding target first side surface;

[0009] A filling structure, located outside the target second side surface, and the filling structure is in contact with the bridge structure and the second surface of the substrate respectively;

[0010] A buffer structure, located on a side of the filling structure facing away from the bridging structure, and the buffer structure covers at least a part of the filling structure;

[0011] A plurality of side running lines located on the target first side surface, one end of each side running line is located on a surface of the bridging structure facing away from the substrate, and the other end sequentially passes through the buffer structure, the second surface and the target first side surface and extends to the first surface.

[0012] Optionally, the bridging structure includes an adhesive layer and a circuit board arranged in a stacked manner, the adhesive layer is bonded to the substrate and the circuit board respectively, the adhesive layer has a third side surface, the circuit board has a fourth side surface, and the target second side surface includes the third side surface and the fourth side surface;

[0013] The filling structure includes a first filling portion, the first filling portion is connected to the third side surface of the adhesive layer, and at least a part of the orthographic projection of the first filling portion on the substrate is located outside the orthographic projection of the circuit board on the substrate.

[0014] Optionally, the first filling portion has a fifth side surface facing away from the adhesive layer, and the fifth side surface includes a connected first sub-surface and a second sub-surface;

[0015] The second sub-surface is located on a side of the first sub-surface away from the second surface, and a first included angle between the first sub-surface and the third surface of the bridging structure is greater than a second included angle between the second sub-surface and the third surface of the bridging structure.

[0016] Optionally, the angle range of the first included angle is 60° to 135°, and the angle range of the second included angle is 30° to 80°.

[0017] Optionally, the first sub-surface and the adhesive layer satisfy a dimensional relationship, and the dimensional relationship includes:

[0018] 1 / 3h ≤ d ≤ 2 / 3h;

[0019] Wherein, the d is the dimension of the first sub-surface in a first direction, the first direction is a direction perpendicular to the second surface, and the h is the thickness of the adhesive layer in the first direction.

[0020] Optionally, the first sub-surface has opposite first and second edges, the first edge is parallel and connected to the second surface, and the second edge is connected to the second sub-surface;

[0021] When the first included angle is greater than 90 degrees, in the second direction, the second edge is located on the side of the first edge closer to the target first side surface, and there is a specified distance between the first edge and the second edge in the second direction, where the specified distance is less than or equal to 20 micrometers, and the second direction is perpendicular to the target first side surface.

[0022] Optionally, the first filling portion has a fifth side surface facing away from the adhesive layer, and the fifth side surface includes a first arc surface, the first arc surface has opposite third and fourth edges, the third edge is parallel and connected to the second surface, and the fourth edge is connected to the edge of the third side surface away from the second surface;

[0023] The first arc surface has an intermediate region between the third edge and the fourth edge, and the intermediate region is located on the side of the third edge and the fourth edge closer to the target first side surface.

[0024] Optionally, the first filling portion has a fifth side surface facing away from the adhesive layer, and the fifth side surface includes a second arc surface, the second arc surface has opposite fifth and sixth edges, the fifth edge is parallel and connected to the second surface, and the sixth edge is connected to the edge of the third side surface away from the second surface;

[0025] The fifth edge is located on the side of the sixth edge closer to the target first side surface.

[0026] Optionally, the first filling portion and the adhesive layer are of an integral structure.

[0027] Optionally, the bridging structure includes an adhesive layer and a circuit board arranged in a stacked manner, the adhesive layer is bonded to the substrate and the circuit board respectively, the adhesive layer has a third side surface, the circuit board has a fourth side surface, the target second side surface includes the third side surface and the fourth side surface, and the third included angle between the third side surface and the third surface is an obtuse angle;

[0028] The filling structure includes a second filling portion, the second filling portion is located outside the target second side surface of the bridging structure, and at least part of the second filling portion is located between the third side surface and the second surface;

[0029] The second filling portion wraps the fourth side surface of the circuit board and the junction between the surface of the circuit board on the side away from the adhesive layer.

[0030] Optionally, the material viscosity of the second filling portion is less than 5000 centipoise.

[0031] Optionally, the bridging structure includes an adhesive layer and a circuit board arranged in a stacked manner. The adhesive layer is bonded to the substrate and the circuit board respectively. The adhesive layer has a third side surface, and the circuit board has a fourth side surface. The target second side surface includes the third side surface and the fourth side surface. The third included angle between the third side surface and the third surface is an obtuse angle.

[0032] The filling structure includes a third filling portion. The third filling portion is located outside the target second side surface of the bridging structure. There is a gap between the third filling portion and the third side surface, and the third filling portion wraps the fourth side surface of the circuit board and the junction between the surface of the circuit board facing away from the adhesive layer.

[0033] Optionally, the material viscosity range of the third filling portion is 45,000 centipoise to 55,000 centipoise.

[0034] According to another aspect of the present application, a manufacturing method of a display panel is provided. The method includes:

[0035] Obtain a substrate, the substrate includes opposite first and second surfaces, and a plurality of first side surfaces connecting the first surface and the second surface. The first surface includes a display area, and the plurality of first side surfaces include at least one target first side surface.

[0036] Arrange a bridging structure and a filling structure on the second surface of the substrate. The bridging structure includes opposite third and fourth surfaces, and a plurality of second side surfaces connecting the third surface and the fourth surface. The third surface is located on the side of the fourth surface close to the substrate. The plurality of second side surfaces include at least one target second side surface. Each target second side surface corresponds to a target first side surface, and the target second side surface has the same orientation as the corresponding target first side surface. The filling structure is located outside the target second side surface and is connected to the bridging structure. The filling structure is located outside the target second side surface, and the filling structure is in contact with the bridging structure and the second surface of the substrate respectively.

[0037] Form a buffer structure on the side of the filling structure away from the bridging structure, and the buffer structure covers at least part of the filling structure.

[0038] Print a plurality of side-walk traces on the substrate formed with the buffer structure. The plurality of side-walk traces are located on the target first side surface. One end of each side-walk trace is located on the surface of the bridging structure away from the substrate, and the other end extends to the first surface through the buffer structure, the second surface, and the target first side surface in sequence.

[0039] Optionally, the bridging structure includes an adhesive layer and a circuit board;

[0040] The steps of disposing the bridging structure and the filling structure on the second surface of the substrate include:

[0041] Attaching the bridging structure to the second surface of the substrate;

[0042] Heating the substrate with the bridging structure to a target temperature, where the target temperature range is 60° to 90°;

[0043] Applying pressure to the side of the circuit board in the bridging structure facing away from the substrate to squeeze the adhesive layer to form the filling structure.

[0044] According to another aspect of the present application, a display device is provided, and the display device includes:

[0045] A display panel as described above;

[0046] A driving circuit board, which is electrically connected to the display panel; the driving circuit board is configured to drive the display panel to display an image.

[0047] According to another aspect of the present application, a tiled display device is provided, and the tiled display device includes a plurality of the above-mentioned display devices.

[0048] The beneficial effects brought by the technical solutions provided in the embodiments of the present application at least include:

[0049] A display panel including a substrate, a bridging structure, a filling structure, a buffer structure, and a plurality of side traces is provided. In this display panel, there is a corner region between the second side surface of the bridging structure and the second surface of the substrate, and the filling structure can be located between the buffer structure and this corner region to reduce the gap between the buffer structure and this corner region. In this way, the bubbles in the buffer structure can be reduced, the flatness of the buffer surface of the buffer structure can be improved, and the side traces located on the buffer structure can be prevented from being open-circuited, so as to improve the quality of the side traces located on the buffer structure, and further improve the yield of the display panel. Description of the Drawings

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0051] Figure 1 It is a schematic structural diagram of a display panel provided by an embodiment of the present application;

[0052] Figure 2 is Figure 1 A schematic cross-sectional structure diagram of the display panel shown along the A1 - A2 position;

[0053] Figure 3 is Figure 2 A schematic structure diagram of the partial 10A of the display panel shown;

[0054] Figure 4 A schematic structure diagram of a display panel;

[0055] Figure 5 is Figure 4 A flowchart of the manufacturing process of the display panel shown;

[0056] Figure 6 is a schematic structure diagram of another display panel;

[0057] Figure 7 is a schematic structure diagram of another display panel;

[0058] Figure 8 is a schematic structure diagram of another display panel;

[0059] Figure 9 is a schematic structure diagram of another display panel provided by an embodiment of the present application;

[0060] Figure 10 is a schematic structure diagram of another display panel provided by an embodiment of the present application;

[0061] Figure 11 is a schematic diagram of the manufacturing process of a display panel provided by an embodiment of the present application;

[0062] Figure 12 is a schematic structure diagram of another display panel provided by an embodiment of the present application;

[0063] Figure 13 is a schematic structure diagram of another display panel provided by an embodiment of the present application;

[0064] Figure 14 is a schematic structure diagram of another display panel provided by an embodiment of the present application;

[0065] Figure 15 is a schematic structure diagram of another display panel provided by an embodiment of the present application;

[0066] Figure 16 is a schematic structure diagram of another display panel provided by an embodiment of the present application;

[0067] Figure 17 is a schematic structure diagram of another display panel provided by an embodiment of the present application;

[0068] Figure 18 It is a schematic structural diagram of another display panel provided by an embodiment of the present application;

[0069] Figure 19 It is a schematic structural diagram of another display panel provided by an embodiment of the present application;

[0070] Figure 20 It is a schematic structural diagram of another display panel provided by an embodiment of the present application;

[0071] Figure 21 It is a schematic structural diagram of another display panel provided by an embodiment of the present application;

[0072] Figure 22 It is a schematic structural diagram of another display panel provided by an embodiment of the present application;

[0073] Figure 23 It is a flowchart of a manufacturing method of a display panel provided by an embodiment of the present application;

[0074] Figure 24 It is a flowchart of another manufacturing method of a display panel provided by an embodiment of the present application.

[0075] Through the above-mentioned drawings, specific embodiments of the present application have been shown, and there will be more detailed descriptions hereinafter. These drawings and textual descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. Specific Embodiments

[0076] To make the objectives, technical solutions, and advantages of the present application clearer, the following will further describe the embodiments of the present application in detail in conjunction with the drawings.

[0077] To improve product reliability, as well as reduce transportation costs and maintenance costs, large-sized display devices can be assembled by splicing multiple small-sized display devices.

[0078] By reducing the border size of a single small-sized display device and the seam width, the sense of display screen fragmentation caused by splicing can be avoided. The small-sized display device includes a display panel. For example, the wiring on one side of the display surface of the display panel can be connected to a circuit board (such as a flexible printed circuit board) provided on the non-display surface side of the display panel through side wiring. Thus, when multiple small-sized display devices are spliced to form a larger-sized large-sized display device, the distance between adjacent small-sized display devices can be smaller, so that the seam width of the large-sized display device formed by splicing multiple small-sized display devices is reduced, and the display quality is improved.

[0079] Please refer to Figure 1 、Figure 2 and Figure 3 , the display panel 10 may include: a substrate 11, a bridging structure 12, a filling structure 13, a buffer structure 14, and a plurality of side traces 15.

[0080] The substrate 11 may include opposite first and second surfaces 11a and 11b, and a plurality of first side surfaces 11c connecting the first surface 11a and the second surface 11b. The first surface 11a may include a display area, and the plurality of first side surfaces 11c may include at least one target first side surface 11cc.

[0081] The bridging structure 12 may be disposed on the second surface 11b of the substrate 11. The bridging structure 12 may include opposite third and fourth surfaces 12a and 12b, and a plurality of second side surfaces 12c connecting the third surface 12a and the fourth surface 12b. The third surface 12a is located on the side of the fourth surface 12b closer to the substrate 11. The plurality of second side surfaces 12c may include at least one second side surface 12cc. Each second side surface 12cc may correspond to a target first side surface 11cc, and the second side surface 12cc and the corresponding target first side surface 11cc have the same orientation.

[0082] The filling structure 13 may be located outside the second side surface 12cc of the bridging structure 12, and the filling structure 13 is in contact with the bridging structure 12 and the second surface 11b of the substrate 11 respectively.

[0083] The buffer structure 14 may be located on the side of the filling structure 13 facing away from the bridging structure 12, and the buffer structure 14 covers at least a part of the filling structure 13.

[0084] The plurality of side traces 15 may be located on the target first side surface 11cc. One end of each side trace 15 is located on the side of the bridging structure 12 facing away from the substrate 11, and the other end sequentially passes through the buffer structure 14, the second surface 11b, and the target first side surface 11cc and extends to the first surface 11a.

[0085] That is, the buffer structure 14 may be located on the side of the filling structure 13 facing away from the substrate 11. The buffer structure 14 may have a buffer surface 14a facing away from the substrate 11. The buffer surface 14a may be a slope surface. At least a part of the side trace 15 may be located on the buffer structure 14 to reduce the influence of the step difference between the fourth surface 12b of the bridging structure 12 and the second surface 11b of the substrate 11 on the side trace 15 through the buffer structure 14.

[0086] It should be noted that Figure 2Shown is the case where the side running line 15 is located on the target first side surface 11cc. In the embodiments of the present application, the side running line 15 may also be located on one or more other first side surfaces 11c. Correspondingly, the filling structure 13 and the buffer structure 14 may also be located outside other second side surfaces 12c.

[0087] In addition, Figure 3 is Figure 2 an enlarged schematic view of the 10A area in the provided display panel 10 (for clear illustration, Figure 3 only the substrate 11, the bridging structure 12, the filling structure 13 and the buffer structure 14 are shown. The 10A area further includes other film layer structures, and the present application does not limit this).

[0088] In the related art, during the manufacturing process of the display panel 10, when the buffer structure 14 is formed outside the second side surface 12c of the bridging structure 12, it is difficult for the buffer structure 14 to completely fill the corner area formed by the second side surface 12c of the bridging structure 12 and the second surface 11b of the substrate 11, resulting in a large gap between the buffer structure 14 and this corner area. The gas in this gap can form bubbles in the buffer structure 14, resulting in poor flatness of the buffer surface 14a of the buffer structure 14, and further resulting in low quality of the side running line 15 formed on the surface of the buffer structure 14 (for example, causing the side running line 15 to be easily open-circuited). Compared with the display panel 10 in the related art, in the embodiments of the present application, by providing a filling structure 13 between the bridging structure 12 and the corner area, the gap between the buffer structure 14 and the corner area can be reduced, the bubbles in the buffer structure 14 can be reduced, the flatness of the buffer surface 14a of the buffer structure 14 can be improved, and the side running line located on the buffer structure 14 can be prevented from being open-circuited, so as to improve the quality of the side running line 15 located on the buffer structure 14, and further improve the yield of the display panel 10.

[0089] In summary, the embodiments of the present application provide a display panel including a substrate, a bridging structure, a filling structure, a buffer structure and a plurality of side running lines. In this display panel, there is a corner area between the second side surface of the bridging structure and the second surface of the substrate. The filling structure can be located between the buffer structure and this corner area to reduce the gap between the buffer structure and this corner area. In this way, the bubbles in the buffer structure can be reduced, the flatness of the buffer surface of the buffer structure can be improved, the side running line located on the buffer structure can be prevented from being open-circuited, so as to improve the quality of the side running line located on the buffer structure, and further improve the yield of the display panel.

[0090] Exemplarily, such as Figure 2As shown, one side of the first surface 11a of the substrate 11 can be the front side of the display panel 10. A display area and a bonding area are provided on one side of the first surface 11a of the substrate 11. Film layer structures such as a driving circuit layer 171, a pad structure 172, and a light-emitting device layer 173 are provided in the display area. The light-emitting device layer 173 includes light-emitting devices of at least three colors. The light-emitting devices of multiple colors at least include a first-color light-emitting device 1731, a second-color light-emitting device 1732, and a third-color light-emitting device 1733. The first color, the second color, and the third color are the three primary colors (for example, red, green, and blue). Exemplarily, the light-emitting device can be a Micro LED (Micro Light Emitting Diode) or a Mini LED (Mini Light Emitting Diode Display).

[0091] The display panel 10 may further include a plurality of back electrodes 161 and a plurality of front electrodes 162. The plurality of front electrodes 162 can be arranged at intervals in the bonding area. At least a part of the plurality of front electrodes 162 is electrically connected to the driving circuit layer 171. One end of a plurality of side running lines 15 can be located on the first surface 11a of the substrate 11 and is electrically connected to the plurality of front electrodes 162 in one-to-one correspondence. The plurality of back electrodes 161 can be arranged at intervals and in parallel on the fourth surface 12b of the bridging structure 12. The other end of the plurality of side running lines 15 can be located on the fourth surface 12b of the bridging structure 12 and is electrically connected to the end portions of the plurality of back electrodes 161 close to the target first side surface 11cc in one-to-one correspondence respectively. In addition, the end portions of the plurality of back electrodes 161 far from the target first side surface 11cc can be bound and connected to an external circuit board 174. The external circuit board 174 can be, for example, a flexible printed circuit board FPC or a printed circuit board PCB, etc. It can be understood that except for the end portions of the back electrodes 161 that need to be connected to the side running lines 15 and the external circuit board 174 as described above and need to be exposed, other areas can be covered by an insulating layer to ensure the reliability of the back electrodes 161. This application does not make any limitations here.

[0092] In some examples, as Figure 2 shown, the display panel 10 may further include a protective layer 175 and a packaging layer 176. The protective layer 175 covers the side running lines 15 and is configured to provide all-round protection to the side running lines 15 to prevent the side running lines 15 from contacting air and / or water vapor and causing water and oxygen corrosion, thereby affecting the conductivity of the side running lines 15. The packaging layer 176 can cover one side of the first surface 11a of the substrate 11. On the one hand, the packaging layer 176 is configured to prevent external light from entering the display area and affecting the display effect. On the other hand, the packaging layer 176 can prevent the light emitted by the light-emitting device layer 173 from leaking at the seams of the tiled display device.

[0093] By providing a bridging structure 12 on the second surface 11b of the substrate 11, the bridging structure 12 can serve as a carrier for a plurality of back electrodes 161. When the display panel 10 includes the bridging structure 12, forming a plurality of back electrodes 161 can be achieved through the following two steps: First, form a plurality of back electrodes 161 on the fourth surface 12b of the bridging structure 12. Second, connect the bridging structure 12 to the second surface 11b of the substrate 11 with high precision, such that the second surface 11b of the substrate 11 contacts the third surface 12a of the bridging structure 12, and at the same time, the front electrodes 162 and the back electrodes 161 correspond to each other one by one in the first direction D1. The front electrodes 162 and the corresponding back electrodes 161 can be connected to the same side running line 15. The first direction D1 is perpendicular to the second surface 11b. Optionally, the front electrodes 162 and the back electrodes 161 can be arranged opposite to each other in the first direction D1 to reduce the manufacturing difficulty of the side running line 15. The process of connecting the bridging structure 12 to the second surface 11b of the substrate 11 with high precision is, for example, bonding. Through the above method, the cost can be reduced, and at the same time, the influence of the etching process on the front film layer and the device can be avoided.

[0094] It should be noted that each of the above-mentioned second side surfaces 12cc corresponding to a target first side surface 11cc means that the number of the second side surfaces 12cc corresponds to that of the target first side surfaces 11cc, and moreover, the second side surfaces 12cc are close to the corresponding target first side surfaces 11cc, and the two are arranged along the first direction D1.

[0095] Please refer to Figure 4 and Figure 5 compared with Figure 2 the display panel 10 shown in Figure 4 the display panel 10 in Figure 5 does not have a filling structure 13 provided. In an optional implementation, in order to achieve high-precision and rapid preparation of the side running line 15 of the display panel 10, the side running line 15 can be prepared by a printing process. In this case, as shown in

[0096] Step 201: Form a plurality of front electrodes 162 on the front surface of the initial substrate.

[0097] In this step, other structures in the driving circuit layer 171 are also formed.

[0098] Step 202: Cut the initial substrate to form a plurality of substrates 11.

[0099] A plurality of front electrodes 162 are provided on the first surface 11a of the substrate 11.

[0100] Step 203: Attach the bridging structure 12 to the second surface 11b of the substrate 11.

[0101] A plurality of back electrodes 161 are provided on the fourth surface 12b of the bridging structure 12, and the back electrodes 161 and the front electrodes 162 are facing each other in the first direction D1.

[0102] Step 204: Form a buffer structure 14 outside the second side surface 12cc of the bridging structure 12.

[0103] The buffer structure 14 can be in contact with the second side surface 12c of the bridging structure 12 and the second surface 11b of the substrate 11 respectively. The process of forming the buffer structure 14 is, for example, screen printing, pad printing, transfer printing, and 3D printing.

[0104] Step 205: Use a printing process to form the conductive paste of the side running trace 15 on the first surface 11a, the target first side surface 11cc, the second surface 11b of the substrate 11, the second side surface 12cc and the fourth surface 12b of the bridging structure 12.

[0105] The above printing process is, for example, screen printing, pad printing, transfer printing, and 3D printing.

[0106] Step 206: Cure the conductive paste to form a plurality of side running traces 15.

[0107] Step 207: Form a protective layer 175 on the surface of the plurality of side running traces 15 away from the substrate 11.

[0108] An initial protective layer 175 can be first formed on the surface of the plurality of side running traces 15 away from the substrate 11, and the initial protective layer 175 is cured to form the protective layer 175.

[0109] Step 208: Transfer a plurality of light-emitting devices to the first surface 11a of the substrate 11, and solder the light-emitting devices to the pads in the driving circuit layer 171 to complete die bonding.

[0110] Step 209: Package the plurality of light-emitting devices.

[0111] Through the above steps, a display panel as shown in Figure 4 can be formed.

[0112] In the manufacturing process of the display panel in the related art, for example, after the above step 206, air bubbles existing in the buffer structure 14 can be observed. Please refer to Figure 6 , Figure 7 and Figure 8 , Figure 6 , Figure 7 and Figure 8 are actual pictures taken during the manufacturing process of the display panel. Figure 6, Figure 7 and Figure 8 are the top - view structural schematic diagrams of the display substrate 11 as viewed along the first direction D1. Figure 4 Shown in the figure.

[0113] It should be noted that, since Figure 6 , Figure 7 and Figure 8 all include the following structures: substrate 11, bridging structure 12, buffer structure 14, side - running wiring 15, back electrode 161, and air bubbles. Among them, the buffer structure 14 and the air bubbles are light - transmissive structures. Therefore, Figure 6 , Figure 7 and Figure 8 are all color drawings in order to clearly show the light - transmissive structures in the display panel. It can be understood that in Figure 6 , Figure 7 and Figure 8 , since the colors of the bridging structure 12 and the substrate 11 are different (the bridging structure 12 can be gold - colored and the substrate 11 can be black - colored), and the buffer structure 14 is a light - transmissive structure, the colors of the buffer structure 14 on the side of the bridging structure 12 facing away from the substrate 11 and the buffer structure 14 on the substrate 11 are different. In addition, when photographing the display panel during the manufacturing process, since the buffer structure 14 can reflect light, there are local reflective areas on the buffer structure 14. Exemplarily, the reflective areas can include Figure 6 , Figure 7 and Figure 8 the edge areas of the buffer structure 14 in, and Figure 7 the area of the buffer structure 14 on the substrate 11 in.

[0114] In the preparation process of the display panel 10 shown in the above Figure 4 , the buffer surface 14a of the buffer structure 14 can be sloped. When preparing the side - running wiring 15 by the printing process, the conductive paste can slowly climb on the outer surface of the buffer structure 14, making the formed conductive paste more uniform, so as to reduce the influence of the step difference between the fourth surface 12b of the bridging structure 12 and the second surface 11b of the substrate 11 on the side - running wiring 15. However, as Figure 6As shown, there are bubbles in the buffer structure 14 in the display panel 10. The bubbles cause the flatness of the buffer surface 14a of the buffer structure 14 to be poor, thereby affecting the shape of the side traces 15 located on the buffer structure 14. For example, when there are bubbles in the buffer structure 14, the line width of the side traces 15 corresponding to the position where the bubbles are located is different from the line width of the side traces 15 corresponding to other positions without bubbles. This situation is because when printing the conductive paste, on the one hand, the distance between the surface of the buffer structure 14 corresponding to the position where the bubbles are located and the nozzle for printing the conductive paste is small, which increases the probability of the two being scratched; on the other hand, the surface of the buffer structure 14 corresponding to the position where the bubbles are located is uneven, showing a convex or concave shape, resulting in that under the same printing conditions, the conductive paste is either difficult to concentrate at the position where the bubbles are located and moves and slides and then accumulates in the surrounding area corresponding to the position where the bubbles are located, resulting in the line width of the subsequently formed side traces 15 corresponding to the position where the bubbles are located becoming smaller; the conductive paste either falls directly into the depression and cannot achieve a continuous linear shape. In severe cases, such as Figure 7 and Figure 8 As shown, the side wiring 15 formed subsequently is broken at the location of the bubble, which reduces the line yield of the side wiring 15.

[0115] The bubbles in the buffer structure 14 may have a diameter ranging from 100 μm to 300 μm (micrometers) and are randomly distributed at the junction between the bridge structure 12 and the buffer structure 14. The inventors have found through observation and research that the bubbles can be mainly divided into the following three types.

[0116] The first type is bubbles that escape from the inside to the outside due to reasons such as the attachment process when the bridging structure 12 and the substrate 11 are relatively fixed by bonding. Such bubbles are caused by the overflow of bubbles due to the floating attachment of the bridging structure 12. For example, the looser the attachment between the two, the larger the bubbles formed. Larger bubbles can expand to the buffer surface 14a of the buffer structure 14, and their diameter can reach more than 500μm.

[0117] The second type is the air bubbles caused by the inward shrinkage of the edge of the bonding layer 121. The bridging structure 12 may include a circuit board 122 and a bonding layer 121, so as to attach the bridging structure 12 to the second surface 11b of the substrate 11 through the bonding layer 121. The manufacturing process of the bridging structure 12 may include the following three steps. First, obtain a carrier board for the bridging structure 12, which may be a circuit board 122 with a relatively large size. Then, form a bonding material layer on one surface of the carrier board, and perform a heating and pressing process on the carrier board with the bonding material layer formed thereon to make the flatness of the bonding material layer on the carrier board relatively high. Finally, cut the carrier board with the bonding material layer formed thereon to form the bridging structure 12, which includes a circuit board 122 and a bonding layer 121. Due to the heating and pressing process in the manufacturing process of the bridging structure 12, there are residual stresses after pressurization inside the bonding layer 121 in the formed bridging structure 12. After cutting to form the bridging structure 12, the edge of the bonding layer 121 shrinks under stress, resulting in the inward shrinkage of the bonding layer 121 relative to the circuit board 122, that is, the edge of the positive projection of the bonding layer 121 on the substrate 11 is located inside the edge of the positive projection of the circuit board 122 on the substrate 11, and the distance range between the edge of the positive projection of the bonding layer 121 on the substrate 11 and the edge of the positive projection of the circuit board 122 on the substrate 11 is 20 μm to 50 μm. The included angle between the third side surface 121c of the bonding layer 121 and the third surface 12a of the bridging structure 12 may be an obtuse angle. The inward shrinkage of the bonding layer 121 will cause a triangular gap s1 to exist between the bridging structure 12 attached to the substrate 11 and the substrate 11. During the subsequent formation of the buffer structure, the gas in the triangular gap s1 will form air bubbles and escape into the buffer structure 14.

[0118] The third type is foreign object air bubbles, that is, there are foreign objects (such as dust) near the second side surface 12cc of the bridging structure 12. When directly forming the buffer structure 14 outside the second side surface 12cc of the bridging structure 12, the foreign objects will cause air bubbles to exist inside the buffer structure 14.

[0119] If the air bubbles fail to escape or burst and solidify in the formed buffer structure 14, the existence of the air bubbles will cause some areas of the buffer surface 14a of the buffer structure 14 to bulge. In this case, when the area of the air bubbles does not interfere with the area of the side walking line 15 to be formed, or the size of the air bubbles is small (diameter < 100 μm), the air bubbles will have little impact on the shape (parameters such as line width) of the side walking line 15 formed on the buffer structure 14; when the size of the air bubbles is large (diameter is 100 μm to 150 μm), such as Figure 6The first air bubble in it will cause the line width of the conductive paste printed on the buffer surface 14a of the buffer structure 14 to be thinner at the position where the first air bubble is located; when the size of the air bubble further increases (diameter > 150 μm), since the buffer surface 14a of the buffer structure 14 bulges at the position corresponding to the air bubble compared to other positions, as Figure 7 shown by the second air bubble in it, when printing the conductive paste, the area with the air bubble in the buffer structure 14 is more likely to scrape the nozzle for printing the conductive paste, resulting in the accumulation of the conductive paste around the area with the air bubble, and it is difficult to form the conductive paste on the area with the air bubble, causing the side running line 15 to be open-circuited and reducing the yield of the side running line 15.

[0120] When the air bubble bursts due to its increasing volume during the escape process and before the buffer structure 14 solidifies, the buffer surface 14a of the buffer structure 14 is concave at the position corresponding to the air bubble compared to other positions, as Figure 8 shown by the third air bubble in it. In this case, although the air bubble bursts, the edge of the burst air bubble is in a convex state relative to the center of the burst air bubble. When printing the conductive paste, the edge of the burst air bubble in the buffer structure 14 is more likely to scrape the nozzle for printing the conductive paste, resulting in the accumulation of the conductive paste around the edge of the burst air bubble, and it is difficult to form the conductive paste in the central area of the burst air bubble, causing the side running line 15 to be open-circuited and reducing the yield of the side running line 15. Among them, according to experimental statistics, the probability that the diameter of the air bubble in the buffer structure 14 is less than or equal to 150 μm is greater than 95%; the probability that the diameter of the air bubble is greater than 150 μm is less than 5%. As Figure 2 shown, in the embodiment of the present application, a filling structure 13 is provided on the side of the buffer structure 14 close to the bridging structure 12. The filling structure 13 can fill the area where the adhesive layer 121 shrinks inward, and can also encapsulate the edge of the bonding surface between the bridging structure 12 and the substrate 11 to prevent air bubbles from escaping, which can reduce the air bubbles in the buffer structure 14 and improve the flatness of the buffer surface 14a of the buffer structure 14.

[0121] Please refer to Figure 9 , in an alternative embodiment, the bridging structure 12 may include an adhesive layer 121 and a circuit board 122 stacked. The adhesive layer 121 is bonded to the substrate 11 and the circuit board 122 respectively. The adhesive layer 121 has a third side surface 121c, and the circuit board 122 has a fourth side surface 122c. The second side surface 12cc may include the third side surface 121c and the fourth side surface 122c.

[0122] The filling structure 13 may include a first filling portion 131. The first filling portion 131 is connected to the third side surface 121c of the adhesive layer 121, and at least part of the orthographic projection of the first filling portion 131 on the substrate 11 is located outside the orthographic projection of the circuit board 122 on the substrate 11.

[0123] The first filling portion 131 can be connected to the adhesive layer 121 and protrude from the circuit board 122 in a direction parallel to the board surface of the substrate 11. In this way, the first filling portion 131 can reduce the influence caused by the shrinkage of the adhesive layer 121, so as to reduce the gap between the bridging structure 12 and the buffer structure 14, and further reduce the air bubbles in the buffer structure 14.

[0124] Please refer to Figure 10 , in an alternative embodiment, the first filling portion 131 may have a fifth side surface 131c facing away from the adhesive layer 121, and the fifth side surface 131c includes a connected first sub-surface 1311 and a second sub-surface 1312.

[0125] The second sub-surface 1312 may be located on a side of the first sub-surface 1311 away from the second surface 11b. A first included angle α1 between the first sub-surface 1311 and the third surface 12a of the bridging structure 12 is greater than a second included angle α2 between the second sub-surface 1312 and the third surface 12a of the bridging structure 12.

[0126] The fifth side surface 131c of the first filling portion 131 may include two sub-surfaces with different slopes. Such a structure has the following two effects. On the one hand, the second sub-surface 1312 with a smaller included angle with the third surface 12a can prevent the adhesive layer 121 from shrinking too much. On the other hand, it is to ensure the sharpness of the cutting tool 181 in the cutting process of forming the bridging structure 12, and the first sub-surface 1311 with a larger included angle with the third surface 12a is cut.

[0127] Please refer to Figure 11 , the first filling portion 131 and the bridging structure 12 can be made by cutting a carrier plate with an adhesive material layer through the same cutting process, so as to simplify the manufacturing process of the display panel 10. The adhesive layer 121 and the first filling portion 131 can be located on the same layer. As Figure 11 shown, the cutting tool 181 used in the cutting process is a double-angle cutting tool 181. The double-angle cutting tool 181 may include two connected first cutting edges 1811 and a second cutting edge 1812. Among them, the first cutting edge 1811 is located on a side of the second cutting edge 1812 close to the edge of the double-angle cutting tool 181. A fifth included angle β1 between the first cutting edge 1811 and the first plane p1 is smaller than a fourth included angle β2 between the second cutting edge 1812 and the first plane. The first plane p1 is a plane perpendicular to the board surface of the circuit board 122. The fourth side surface 122c of the circuit board 122 and the fifth side surface 131c of the first filling portion 131 formed by cutting with the double-angle cutting tool 181 can both be inclined planes, which can improve the phenomenon of shrinkage of the adhesive layer 121.

[0128] In an exemplary embodiment, the angle range of the fifth angle β1 can be 15° to 30°. Within this range, the sharpness of the double-angle tool 181 can be relatively good. The angle range of the fourth angle β2 can be 45° to 60°. Within this range, the sharpness of the double-angle tool 181 is relatively good, and at the same time, the slope of the second sub-surface 1312 of the first filling portion 131 after cutting is relatively small (that is, the angle between the second sub-surface 1312 and the third surface 12a is relatively small), so as to improve the phenomenon of the shrinkage of the adhesive layer 121.

[0129] Please refer to Figure 12 and Figure 13 , optionally, the angle range of the first angle α1 can be 60° to 135°, and the angle range of the second angle α2 can be 30° to 80°. The material of the first filling portion 131 can include an organic material. Exemplarily, the material of the first filling portion 131 can include at least one of a pressure-sensitive adhesive or a thermosetting adhesive. Due to the action of residual stress, the first filling portion 131 formed after cutting may exhibit a shrinkage phenomenon. Since the internal residual stress of the material is affected by aspects such as equipment accuracy, human intervention, and natural aging in the manufacturing process, the shrinkage degree of different display panels may be different. Therefore, as Figure 10 , Figure 11 and Figure 13 shown, the first filling portion 131 can have various forms.

[0130] As Figure 10 and Figure 11 shown, the first filling portion 131 can have a first form. The dashed line m1 represents the position of the first filling portion 131 before shrinkage, and the shape of the dashed line m1 is the same as the shape of the blade of the tool 181. When the residual stress in the adhesive layer 121 and the first filling portion 131 is relatively small, the first filling portion 131 slightly shrinks inward, and the first angle α1 between the first sub-surface 1311 and the third surface 12a becomes larger than the angle between the first sub-surface 1311 and the third surface 12a during cutting. In the second direction D2, the edge retraction dimension X of the first filling portion 131 < d × tan(β1), where the second direction D2 is perpendicular to the target first side surface 11cc, d is the dimension of the first sub-surface 1311 in the first direction D1, the first direction D1 is perpendicular to the second surface 11b, β1 is the fifth angle between the first blade 1811 and the first plane, and the edge in the edge retraction dimension can refer to the edge where the fifth side surface 131c is connected to the second surface 11b. In this form, the first angle α1 can be an acute angle.

[0131] As Figure 12 and Figure 11As shown, the first filling portion 131 may have a second form. When the internal residual stress in the adhesive layer 121 and the first filling portion 131 is relatively large, in the second direction D2, the edge retraction dimension X of the first filling portion 131 is X = d × tan(β1). In this form, the first included angle α1 may be a right angle.

[0132] As Figure 12 and Figure 11 shown, the first filling portion 131 may have a third form. When the internal residual stress in the adhesive layer 121 and the first filling portion 131 is even larger, the edge retraction dimension satisfies the following range: d × tan(β1) < X < [(h - d) × tan(β2) + d × tan(β1)], where h is the thickness of the adhesive layer 121 in the first direction D1. In this form, the first included angle α1 may be an obtuse angle, the first sub-surface 1311 of the first filling portion 131 is in a retracted state, and the first filling portion 131 as a whole protrudes toward the target first side surface 11cc with respect to the circuit board 122.

[0133] Exemplarily, the material of the circuit board 122 is polyimide. The polyimide material has characteristics such as high precision, high temperature resistance, and low expansion and contraction, making the circuit board 122 not easily displaced during subsequent high-temperature processes, such as reflow soldering.

[0134] In some embodiments, the thickness of the adhesive layer 121 is greater than the thickness of the circuit board 122. By setting it like this, the connection firmness between the circuit board 122 and the substrate 11 can be increased, and the circuit board 122 can be prevented from moving during subsequent processes of the display panel 10, which may affect the position accuracy of the back electrode 161. Among them, the thickness range of the circuit board 122 can be 37.5μm to 52.5μm, and the thickness range of the adhesive layer 121 can be 20μm to 60μm. The thickness of the bridging structure 12 is less than or equal to 0.1mm, so that the display panel 10 is relatively thin and light.

[0135] Please refer to Figure 10 , optionally, the first sub-surface 1311 and the adhesive layer 121 satisfy a dimensional relationship, and the dimensional relationship includes:

[0136] 1 / 3h ≤ d ≤ 2 / 3h;

[0137] Wherein, d is the dimension of the first sub-surface 1311 in the first direction D1, the first direction D1 is perpendicular to the second surface 11b, and h is the thickness of the adhesive layer 121 in the first direction D1. It can be seen that the connection between the first sub-surface 1311 and the second sub-surface 1312 is horizontally located at the adhesive layer 121. Since the first included angle α1 is greater than the second included angle α2, the first sub-surface 1311 is more likely to shrink inwards compared to the second sub-surface 1312. When the dimension of the first sub-surface 1311 satisfies the dimension relationship, it is possible to avoid the dimension of the first sub-surface 1311 from being too large, so as to avoid excessive inward shrinkage of the first sub-surface 1311.

[0138] Please refer to Figure 13 , optionally, the first sub-surface 1311 has opposite first and second edges b1 and b2. The first edge b1 is parallel and connected to the second surface 11b, and the second edge b2 is connected to the second sub-surface 1312. When the first included angle α1 is greater than 90 degrees, in the second direction D2, the second edge b2 is located on the side of the first edge b1 closer to the target first side surface 11cc, and the first edge b1 and the second edge b2 have a specified distance L1 in the second direction D2. The specified distance L1 is less than or equal to 20 micrometers, and the second direction D2 is perpendicular to the target first side surface 11cc. When the first sub-surface 1311 shrinks inwards, since the dimension of the first sub-surface 1311 in the second direction D2 is smaller than the dimension of the second sub-surface 1312 in the second direction D2, the inward shrinkage dimension of the first sub-surface 1311 is smaller, making the entire first filling portion 131 protrude towards the target first side surface 11cc relative to the circuit board 122, so as to avoid affecting the subsequent formed buffer structure 14.

[0139] Please refer to Figure 14 and Figure 15 , in an optional implementation manner, the first filling portion 131 may have a fifth side surface 131c facing away from the adhesive layer 121. The fifth side surface 131c includes a first arc surface 1313. The first arc surface 1313 has opposite third and fourth edges b3 and b4. The third edge b3 is parallel and connected to the second surface 11b, and the fourth edge b4 is connected to the edge of the third side surface 121c away from the second surface 11b. The first arc surface 1313 has an intermediate region z1 between the third edge b3 and the fourth edge b4. The intermediate region z1 may be located on the side of the third edge b3 and the fourth edge b4 closer to the target first side surface 11cc. The first filling portion 131 can be formed by extruding the adhesive layer 121, which can simplify the manufacturing process of the display panel 10.

[0140] A high-temperature and high-pressure process can be added after the bridging structure 12 is attached to the substrate 11. According to the temperature-viscosity curve, by using the property that the organic material has a reduced viscosity and increased fluidity at a preset temperature, the ambient temperature of the substrate 11 provided with the bridging structure 12 is set to the preset temperature. By increasing the air pressure by placing the substrate 11 provided with the bridging structure 12 in a closed space, or by uniformly pressing a heavy object against the side of the bridging structure 12 facing away from the substrate 11, the adhesive layer 121 can flow sufficiently, which can solve the problem of the bridging structure 12 floating and pasting, and can also make the adhesive layer 121 uniformly overflow at the second side surface 12cc of the bridging structure 12 to form a first filling portion 131 to solve the problem of the adhesive layer 121 shrinking inwards. The range of the preset temperature can be 60° to 90°. In this way, the bubbles in the subsequently formed buffer structure 14 can be reduced to improve the flatness of the buffer surface 14a of the buffer structure 14, and further improve the yield of the side walking lines 15 located on the buffer structure 14.

[0141] It can be understood that, as Figure 14 shown, when the first filling portion 131 is in the Figure 14 form shown, there may be a very small gap between the buffer structure 14, the fifth side surface 131c of the first filling portion 131, and the second surface 11b of the substrate 11. Since the size of this gap is extremely small, the probability of the air in this gap forming bubbles in the buffer structure 14 is small. Even if the air in this gap forms bubbles in the buffer structure 14, the size of the bubbles is small and will not affect the flatness of the surface of the buffer structure 14.

[0142] Please refer to Figure 16 and Figure 17 , in an optional implementation manner, the first filling portion 131 may have a fifth side surface 131c facing away from the adhesive layer 121. The fifth side surface 131c includes a second arc surface 1314. The second arc surface 1314 has opposite fifth edge b5 and sixth edge b6. The fifth edge b5 is parallel and connected to the second surface 11b, and the sixth edge b6 is connected to the edge of the third side surface 121c away from the second surface 11b. The fifth edge b5 may be located on the side of the sixth edge b6 close to the target first side surface 11cc. In this way, the fifth side surface 131c of the first filling portion 131 can be in a slope shape. The bubbles in the subsequently formed buffer structure 14 can be reduced to improve the flatness of the buffer surface 14a of the buffer structure 14, and further improve the yield of the side walking lines 15 located on the buffer structure 14.

[0143] After the high-temperature and high-pressure process, the form in which the adhesive layer 121 overflows (i.e., the form of the formed first filling portion 131) will have two forms due to reasons such as different materials, different ambient temperatures, or different surface tensions of the adhesive layer 121. Among them, the first form is as Figure 15As shown, the second form is as follows Figure 17 shown Figure 17 In Figure 17 , the environmental temperature of the adhesive layer 121 in the high-temperature and high-pressure process is set appropriately, so that the fluidity of the adhesive layer 121 is better, and the fifth side surface 131c of the first filling portion 131 formed can be in a sloped shape.

[0144] Figure 15 The environmental temperature of the adhesive layer 121 in during the high-temperature and high-pressure process is lower or higher than that of the adhesive layer 121 in Figure 17 during the high-temperature and high-pressure process, making the fluidity of the adhesive layer 121 relatively poor, the surface tension of the adhesive layer 121 is large, and the fifth side surface 131c of the first filling portion 131 formed can be in an arc shape.

[0145] Please refer to Figure 18 , Figure 19 and Figure 20 , optionally, the first filling portion 131 and the adhesive layer 121 can be an integral structure, which can improve the connection stability between the adhesive layer 121 and the first filling portion 131, and can also avoid gaps between the adhesive layer 121 and the first filling portion 131.

[0146] Please refer to Figure 21 , optionally, the bridging structure 12 can include an adhesive layer 121 and a circuit board 122 arranged in a stacked manner. The adhesive layer 121 is bonded to the substrate 11 and the circuit board 122 respectively. The adhesive layer 121 has a third side surface 121c, and the circuit board 122 has a fourth side surface 122c. The second side surface 12cc includes the third side surface 121c and the fourth side surface 122c, and the third included angle α3 between the third side surface 121c and the third surface 12a is an obtuse angle.

[0147] The filling structure 13 can include a second filling portion 132, and the second filling portion 132 is located outside the second side surface 12cc of the bridging structure 12, and at least part of the second filling portion 132 is located between the third side surface 121c and the second surface 11b.

[0148] The second filling portion 132 can wrap the fourth side surface 122c of the circuit board 122 and the junction portion T between the surface of the circuit board 122 facing away from the adhesive layer 121.

[0149] Optionally, the material viscosity of the second filling portion 132 is less than 5000 centipoises (cp).

[0150] The buffer structure 14 needs to have a good surface flatness to support the side routing 15. In the embodiment of the present application, the viscosity range of the buffer material of the buffer structure 14 is 15000 cp to 30000 cp. The adhesive layer 121 in the bridging structure 12 has a retraction phenomenon. If the filling structure 13 is not provided and the buffer material is directly printed outside the second side surface 12cc of the bridging structure 12, since the buffer material at this viscosity has a certain fluidity, the air bubbles between the buffer material and the bridging structure 12 may escape from the buffer material. At the same time, the buffer material at this viscosity has a certain resistance to the overflow of air bubbles, making the air bubbles unable to break through the buffer material and escape completely, resulting in the air bubbles being sealed in the buffer material and solidifying with the buffer material. When the volume of the air bubble is relatively large, the escaping force of the air bubble is relatively large and can break through the buffer material and escape completely, but the leveling property of the buffer material is not sufficient to level again before curing, resulting in a poor surface flatness of the formed buffer structure 14.

[0151] In the embodiment of the present application, the second filling portion 132 formed of a material with a lower viscosity (higher fluidity) can be used to fill the space between the second side surface 12c of the bridging structure 12 and the second surface 11b of the substrate 11, and then the buffer structure 14 is formed on the second filling portion 132 to reduce the air bubbles in the buffer structure 14. That is, first print the filling material outside the second side surface 12cc of the bridging structure 12. The viscosity of the filling material is less than 5000 cp, and the ultrasonic device is used to vibrate the substrate 11 to promote the flow of the filling material, and at the same time enable the air bubbles to escape from the filling structure 13. Moreover, after the air bubbles escape and burst, the surface of the area where the air bubbles escape and burst in the printed filling material can be leveled again to avoid affecting the flatness of the surface of the printed filling material, so that the surface flatness of the printed filling material is better. After the filling material fills the space between the second side surface 12c of the bridging structure 12 and the second surface 11b of the substrate 11, the filling material is cured to form the second filling portion 132, and then the buffer material is printed on the second filling portion 132, so that the flatness of the buffer surface 14a of the formed buffer structure 14 is better, thereby improving the yield of the side routing 15 located on the buffer structure 14.

[0152] In addition, since the interface T is relatively sharp, if the buffer structure 14 is in direct contact with the interface T, the shape of the buffer structure 14 at this position will not be smooth enough, which will lead to a low surface flatness of the buffer structure 14. The second filling portion 132 in the embodiment of the present application can wrap the interface T between the fourth side surface 122c of the circuit board 122 and the surface of the circuit board 122 on the side away from the adhesive layer 121. This can prevent the interface T from affecting the flatness of the buffer surface 14a of the buffer structure 14. Moreover, in the related art, since the buffer structure needs to fill the space between the second side surface 12c of the bridging structure 12 and the second surface 11b of the substrate 11, the formed buffer structure has a depression. The second filling portion 132 can fill the space between the second side surface 12c of the bridging structure 12 and the second surface 11b of the substrate 11, which can prevent the subsequent formation of a depression in the buffer structure 14.

[0153] Please refer to Figure 22 Optionally, the bridging structure 12 includes a stacked adhesive layer 121 and a circuit board 122, the adhesive layer 121 is respectively bonded to the substrate 11 and the circuit board 122, the adhesive layer 121 has a third side surface 121c, the circuit board 122 has a fourth side surface 122c, the second side surface 12cc includes the third side surface 121c and the fourth side surface 122c, and the third angle α3 between the third side surface 121c and the third surface 12a is an obtuse angle.

[0154] The filling structure 13 includes a third filling portion 133, which is located outside the second side surface 12cc of the bridging structure 12. There is a gap between the third filling portion 133 and the third side surface 121c, and the third filling portion 133 wraps the fourth side surface 122c of the circuit board 122 and the boundary portion T between the surface of the circuit board 122 facing away from the adhesive layer 121.

[0155] Optionally, the viscosity of the material of the third filling part 133 ranges from 45,000 centipoise to 55,000 centipoise.

[0156] In the embodiment of the present application, a third filling portion 133 formed of a material with a relatively high viscosity (relatively low fluidity) can be used to seal the space between the second side surface 12c of the bridge structure 12 and the second surface 11b of the substrate 11. This third filling portion 133 can inhibit the escape of bubbles. The buffer structure 14 is then formed on the third filling portion 133 to reduce the number of bubbles in the buffer structure 14. In other words, the relatively high viscosity of the third filling portion 133 can prevent bubbles from escaping, resulting in a higher surface flatness for the third filling portion 133, and thus a higher surface flatness for the buffer structure 14.

[0157] like Figure 22As shown, in an alternative embodiment, there is a gap s2 between a partial region of the third filling portion 133 and the bridging structure 12. The size of the gap s2 ranges from 1 μm to 150 μm in a direction perpendicular to the target first side surface 11cc, and ranges from 1 μm to 100 μm in a direction perpendicular to the plate surface of the substrate 11.

[0158] In summary, the embodiments of the present application provide a display panel including a substrate, a bridging structure, a filling structure, a buffer structure, and multiple side traces. In this display panel, there is a corner region between the second side surface of the bridging structure and the second surface of the substrate. The filling structure can be located between the buffer structure and this corner region to reduce the gap between the buffer structure and this corner region. In this way, the bubbles in the buffer structure can be reduced, the flatness of the buffer surface of the buffer structure can be improved, and the side traces located on the buffer structure can be prevented from being open-circuited, so as to improve the quality of the side traces located on the buffer structure, and thus the yield of the display panel can be improved.

[0159] The embodiments of the present application also provide a manufacturing method of a display panel. Please refer to Figure 23 , the manufacturing method of the display panel includes:

[0160] Step 301, obtain a substrate.

[0161] The substrate 11 may include opposite first surface 11a and second surface 11b, and multiple first side surfaces 11c connecting the first surface 11a and the second surface 11b. The first surface 11a may include a display area, and the multiple first side surfaces 11c may include at least one target first side surface 11cc. Film layer structures such as a front electrode 162 and a driving circuit layer 171 are provided on the first surface of the substrate.

[0162] Step 302, provide a bridging structure and a filling structure on the second surface of the substrate.

[0163] The bridging structure 12 may be provided on the second surface 11b of the substrate 11. The bridging structure 12 may include opposite third surface 12a and fourth surface 12b, and multiple second side surfaces 12c connecting the third surface 12a and the fourth surface 12b. The third surface 12a is located on the side closer to the substrate 11 than the fourth surface 12b. The multiple second side surfaces 12c may include at least one second side surface 12cc. Each second side surface 12cc may correspond to a target first side surface 11cc, and the second side surface 12cc has the same orientation as the corresponding target first side surface 11cc. The filling structure 13 may be located outside the second side surface 12cc of the bridging structure 12, and the filling structure 13 is in contact with the second side surface 12cc of the bridging structure 12 and the second surface 11b of the substrate 11 respectively.

[0164] Step 303: Form a buffer structure on a side of the filling structure facing away from the bridging structure, and the buffer structure covers at least a part of the filling structure.

[0165] The process of forming the buffer structure 14 is, for example, screen printing, pad printing, transfer printing, and 3D printing.

[0166] Step 304: Print a plurality of side traces on the substrate with the buffer structure formed thereon.

[0167] Among them, the plurality of side traces are located on the target first side surface. One end of each side trace is located on a surface of the bridging structure facing away from the substrate, and the other end extends to the first surface through the buffer structure, the second surface, and the target first side surface in sequence.

[0168] Exemplarily, the process of forming the plurality of side traces 15 is a printing process. The printing process is, for example, screen printing, pad printing, transfer printing, and 3D printing.

[0169] In some embodiments, in the manufacturing method of the display panel, when the bridging structure includes an adhesive layer 121 and a circuit board 122, as Figure 24 shown, step 302 may include the following three sub-steps:

[0170] Sub-step 3021: Attach the bridging structure to the second surface of the substrate.

[0171] There is a back electrode 161 on the fourth surface 12b of the bridging structure 12. The process of disposing the bridging structure 12 on the second surface of the substrate 11 is, for example, high-precision attachment, so that the back electrode 161 is directly opposite to the front electrode 162 in the first direction D1.

[0172] Sub-step 3022: Heat the substrate with the bridging structure to a target temperature.

[0173] The target temperature range is 60° to 90°. Within this temperature range, the fluidity of the adhesive layer 121 is relatively good.

[0174] Sub-step 3023: Apply pressure to a side of the circuit board in the bridging structure facing away from the substrate to squeeze the adhesive layer and form a filling structure.

[0175] Uniformly applying pressure to the side of the bridging structure 12 facing away from the substrate 11 with a heavy object, so that the adhesive layer 121 flows sufficiently, can solve the problem of the bridging structure 12 floating, and can also make the adhesive layer 121 uniformly overflow at the target second side surface 12cc of the bridging structure 12 to form a first filling portion 131 to solve the problem of the adhesive layer 121 shrinking. In this way, the bubbles in the subsequently formed buffer structure 14 can be reduced to improve the flatness of the buffer surface 14a of the buffer structure 14, and further improve the yield of the side traces 15 located on the buffer structure 14.

[0176] In summary, the embodiment of the present application provides a manufacturing method of a display panel. The display panel includes a substrate, a bridging structure, a filling structure, a buffer structure, and a plurality of side running traces. In the display panel, there is a corner region between the second side surface of the bridging structure and the second surface of the substrate. The filling structure can be located between the buffer structure and the corner region to reduce the gap between the buffer structure and the corner region. In this way, the bubbles in the buffer structure can be reduced, the flatness of the buffer surface of the buffer structure can be improved, and the side running traces located on the buffer structure can be prevented from being open-circuited, so as to improve the quality of the side running traces located on the buffer structure, and further improve the yield of the display panel.

[0177] On the other hand, the embodiment of the present application provides a display device. The display device includes: a display panel in any of the above embodiments; a driving circuit board, the driving circuit board is electrically connected to the display panel; the driving circuit board is configured to drive the display panel to display an image.

[0178] The display device can be any device that displays moving (e.g., video), stationary (e.g., still image), textual, or graphical content. More specifically, it is contemplated that the embodiments may be implemented in or associated with a variety of electronic devices, such as (but not limited to) mobile phones, wireless devices, personal digital assistants (PDAs), handheld or portable computers, GPS receivers / navigators, cameras, MP4 video players, camcorders, game consoles, watches, clocks, calculators, television monitors, flat panel displays, computer monitors, automotive displays (e.g., odometer displays, etc.), navigators, cockpit controllers and / or displays, displays for camera views (e.g., displays for rear view cameras in vehicles), electronic photos, electronic billboards or signs, projectors, architectural structures, packaging, and aesthetic structures (e.g., displays for images of a piece of jewelry), etc.

[0179] Exemplarily, the above display device may further include a frame and other electronic accessories, etc. Among them, the display panel can be disposed within the frame.

[0180] On the other hand, the embodiment of the present application provides a tiled display device. The tiled display device includes a plurality of the above display devices. The plurality of display devices in the tiled display device can be arranged in an array.

[0181] In the present application, the term "at least one of A and B" is merely a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, at least one of A and B can represent: A exists alone, A and B exist simultaneously, and B exists alone.

[0182] It should be noted that in the accompanying drawings, the dimensions of layers and regions may be exaggerated for clarity of illustration. Also, it is understood that when an element or layer is referred to as being "on" another element or layer, it can be directly on the other element, or there may be intervening layers. Additionally, it is understood that when an element or layer is referred to as being "under" another element or layer, it can be directly under the other element, or there may be more than one intervening layer or element. Further, it is understood that when a layer or element is referred to as being "between" two layers or two elements, it can be the only layer between the two layers or two elements, or there may also be more than one intervening layer or element. Like reference numerals throughout the specification indicate like elements.

[0183] In this application, the terms "first", "second", "third" and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "plurality" means two or more unless otherwise specifically defined.

[0184] The above are only alternative embodiments of this application and are not intended to limit this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of this application shall be included within the protection scope of this application.

Claims

1. A display panel, characterized in that, The display panel includes: a substrate including opposite first and second surfaces, and a plurality of first side surfaces connecting the first surface and the second surface, the first surface including a display area, and the plurality of first side surfaces including at least one target first side surface; a bridging structure disposed on the second surface, the bridging structure including opposite third and fourth surfaces, and a plurality of second side surfaces connecting the third surface and the fourth surface, the third surface being on a side of the fourth surface close to the substrate, the plurality of second side surfaces including at least one target second side surface, each target second side surface corresponding to a target first side surface, and the target second side surface having the same orientation as the corresponding target first side surface; a filling structure located outside the target second side surface, and the filling structure being in contact with the bridging structure and the second surface of the substrate respectively; a buffer structure located on a side of the filling structure away from the bridging structure, and the buffer structure covering at least part of the filling structure; a plurality of side traces located on the target first side surface, one end of each side trace being on a surface of the bridging structure away from the substrate, and the other end sequentially passing through the buffer structure, the second surface, and the target first side surface and extending to the first surface.

2. The display panel according to claim 1, wherein The bridging structure includes an adhesive layer and a circuit board stacked, the adhesive layer being adhered to the substrate and the circuit board respectively, the adhesive layer having a third side surface, the circuit board having a fourth side surface, and the target second side surface including the third side surface and the fourth side surface; The filling structure includes a first filling portion, the first filling portion being connected to the third side surface of the adhesive layer, and at least part of a positive projection of the first filling portion on the substrate being located outside a positive projection of the circuit board on the substrate.

3. The display panel according to claim 2, wherein The first filling portion has a fifth side surface facing away from the adhesive layer, and the fifth side surface includes a connected first sub-surface and a second sub-surface; The second sub-surface is on a side of the first sub-surface away from the second surface, and a first angle between the first sub-surface and the third surface of the bridging structure is greater than a second angle between the second sub-surface and the third surface of the bridging structure.

4. The display panel according to claim 3, wherein The angle range of the first angle is 60° to 135°, and the angle range of the second angle is 30° to 80°.

5. The display panel according to claim 3, characterized in that, The first sub-surface and the adhesive layer satisfy a dimensional relationship, and the dimensional relationship includes: 1 / 3h ≤ d ≤ 2 / 3h; wherein, d is a dimension of the first sub-surface in a first direction, the first direction being a direction perpendicular to the second surface, and h is a thickness of the adhesive layer in the first direction.

6. The display panel according to claim 3, wherein, The first sub-surface has opposite first and second edges, the first edge being parallel and connected to the second surface, and the second edge being connected to the second sub-surface; When the first included angle is greater than 90 degrees, in the second direction, the second edge is located on the side of the first edge closer to the target first side surface, and there is a specified distance between the first edge and the second edge in the second direction, and the specified distance is less than or equal to 20 micrometers. The second direction is perpendicular to the target first side surface.

7. The display panel according to claim 2, wherein, The first filling portion has a fifth side surface facing away from the adhesive layer. The fifth side surface includes a first arc surface. The first arc surface has opposite third and fourth edges. The third edge is parallel and connected to the second surface, and the fourth edge is connected to the edge of the third side surface away from the second surface. The first arc surface has an intermediate region between the third edge and the fourth edge, and the intermediate region is located on the side of the third edge and the fourth edge closer to the target first side surface.

8. The display panel according to claim 2, wherein The first filling portion has a fifth side surface facing away from the adhesive layer. The fifth side surface includes a second arc surface. The second arc surface has opposite fifth and sixth edges. The fifth edge is parallel and connected to the second surface, and the sixth edge is connected to the edge of the third side surface away from the second surface. The fifth edge is located on the side of the sixth edge closer to the target first side surface.

9. The display panel according to claim 2, wherein, The first filling portion and the adhesive layer are of an integral structure.

10. The display panel according to claim 1, characterized in that, The bridging structure includes a stacked adhesive layer and a circuit board. The adhesive layer is bonded to the substrate and the circuit board respectively. The adhesive layer has a third side surface, and the circuit board has a fourth side surface. The target second side surface includes the third side surface and the fourth side surface. The third included angle between the third side surface and the third surface is an obtuse angle. The filling structure includes a second filling portion. The second filling portion is located outside the target second side surface of the bridging structure, and at least part of the second filling portion is located between the third side surface and the second surface. The second filling portion wraps the junction between the fourth side surface of the circuit board and the surface of the circuit board on the side away from the adhesive layer.

11. The display panel according to claim 10, wherein The material viscosity of the second filling portion is less than 5000 centipoises.

12. The display panel according to any one of claims 2, characterized in that, The bridging structure includes a stacked adhesive layer and a circuit board. The adhesive layer is bonded to the substrate and the circuit board respectively. The adhesive layer has a third side surface, and the circuit board has a fourth side surface. The target second side surface includes the third side surface and the fourth side surface. The third included angle between the third side surface and the third surface is an obtuse angle. The filling structure includes a third filling portion. The third filling portion is located outside the target second side surface of the bridging structure. There is a gap between the third filling portion and the third side surface, and the third filling portion wraps the junction between the fourth side surface of the circuit board and the surface of the circuit board on the side away from the adhesive layer.

13. The display panel according to any one of claims 12, characterized in that, The material viscosity range of the third filling portion is 45000 centipoises to 55000 centipoises.

14. A manufacturing method of a display panel, characterized in that, The method includes: Obtain a substrate, the substrate including opposite first and second surfaces, and a plurality of first side surfaces connecting the first surface and the second surface, the first surface including a display area, and the plurality of first side surfaces including at least one target first side surface; Provide a bridging structure and a filling structure on the second surface of the substrate, the bridging structure including opposite third and fourth surfaces, and a plurality of second side surfaces connecting the third surface and the fourth surface, the third surface being on the side of the fourth surface close to the substrate, the plurality of second side surfaces including at least one target second side surface, each target second side surface corresponding to a target first side surface, and the target second side surface having the same orientation as the corresponding target first side surface, the filling structure being located outside the target second side surface and connected to the bridging structure, the filling structure being located outside the target second side surface, and the filling structure being in contact with the bridging structure and the second surface of the substrate respectively; Form a buffer structure on the side of the filling structure facing away from the bridging structure, and the buffer structure covers at least a part of the filling structure; Print a plurality of side traces on the substrate with the buffer structure formed thereon, the plurality of side traces being located on the target first side surface, one end of each side trace being on the side of the bridging structure facing away from the substrate, and the other end extending to the first surface successively through the buffer structure, the second surface and the target first side surface.

15. The method according to claim 14, characterized in that, The bridging structure includes an adhesive layer and a circuit board; The providing a bridging structure and a filling structure on the second surface of the substrate includes: Attach the bridging structure to the second surface of the substrate; Heat the substrate with the bridging structure to a target temperature, the target temperature range being 60° to 90°; Apply pressure to the side of the circuit board in the bridging structure facing away from the substrate to squeeze the adhesive layer to form the filling structure.

16. A display device, characterized in that, Include: A display panel according to any one of claims 1 to 13; A driving circuit board, the driving circuit board being electrically connected to the display panel; The driving circuit board is configured to drive the display panel to display an image.

17. A splicing display device, characterized in that, Include a plurality of display devices according to claim 16.

Images