Display panel, display device, and tiled display device

Abstract

A display panel comprises: a substrate, a bridging structure, a plurality of back electrodes, and a plurality of connecting leads. The substrate comprises a first surface and a second surface disposed opposite each other, and at least one selected first side surface. The bridging structure comprises a third surface and a fourth surface, and at least one selected second side surface. A plurality of back electrodes are arranged in parallel and spaced relation on the fourth surface. The third portion of each connecting lead is electrically connected to a back electrode; the third surface and the fourth surface have a first spacing. The first common edge is the intersection of the selected second side surface and the fourth surface, the second common edge is the intersection of the selected second side surface and the third surface, the orthographic projection of the first common edge on the third surface and the orthographic projection of the second common edge on the third surface have a second spacing, and the ratio of the first spacing to the second spacing is between 0.27 and 1.73. The distance between the second common edge and the first selected side surface is a third spacing, and the value range of the third spacing is between 0.5 mm and 2.0 mm. The above-mentioned display panel is used to display images.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of display, and in particular, to a display panel, a display device and a spliced display device. BACKGROUND

[0002] Micro LED (Micro Light Emitting Diode) and Mini LED (Mini Light Emitting Diode Display) have smaller particles, i.e. smaller volume, compared to traditional LEDs, and are widely used in display devices to form Micro LED / Mini LED display devices, which have higher display effects. SUMMARY

[0003] In one aspect, a display panel is provided, comprising: a substrate, a bridge structure, a plurality of back electrodes, and a plurality of connecting leads. The substrate comprises a first surface and a second surface arranged oppositely, and a plurality of first side surfaces connecting the first surface and the second surface; the plurality of first side surfaces comprises at least one selected first side surface. The bridge structure is arranged on the second surface; the bridge structure comprises a third surface and a fourth surface arranged oppositely, and a plurality of second side surfaces connecting the third surface and the fourth surface; the third surface is closer to the substrate than the fourth surface; the plurality of second side surfaces comprises at least one selected second side surface; each selected second side surface corresponds to one selected first side surface. The plurality of back electrodes are arranged in parallel and at intervals on the fourth surface. The plurality of connecting leads are arranged in parallel and at intervals; each connecting lead comprises a first part on one side of the first surface, a second part on one side of the selected first side surface, and a third part on one side of the second surface; the third part of each connecting lead is electrically connected to one back electrode; the third part of the connecting lead comprises a part on the second surface, a part on the selected second side surface, and a part on one side of the fourth surface; the third surface and the fourth surface have a first interval. Wherein, a first common edge is the intersection line of the selected second side surface and the fourth surface, a second common edge is the intersection line of the selected second side surface and the third surface, the orthographic projection of the first common edge on the third surface and the orthographic projection of the second common edge on the third surface have a second interval, and the ratio of the first interval to the second interval is 0.27-1.73. The distance between the second common edge and the first selected side surface is a third interval, and the value of the third interval is 0.5-2.0 mm.

[0004] In some embodiments, the connecting lead has a first thickness at a portion corresponding to the region where the fourth surface is located, a second thickness at a portion corresponding to the region where the second surface is located, and a third thickness at a position corresponding to the selected second side surface; wherein the first thickness is greater than or equal to the second thickness, and the difference between the first thickness and the second thickness is 0-1 μm; the third thickness is greater than the first thickness or the second thickness, and the difference between the third thickness and the first thickness or the second thickness is 1 μm-3 μm.

[0005] In some embodiments, a cross section of the selected second side surface perpendicular to the first common edge or the second common edge is a straight line segment, a curved line segment, or a broken line segment, and the curved line segment curves away from the second surface.

[0006] In some embodiments, the selected second side surface is a plane, and an included angle between the selected second side surface and the third surface ranges from 10° to 80°.

[0007] In some embodiments, the selected second side surface comprises a plurality of sub-surfaces connected in sequence; among two adjacent sub-surfaces, the sub-surface farther away from the selected first side surface is relatively farther away from the second surface than the other sub-surface.

[0008] In some embodiments, the plurality of sub-surfaces are planes, and the selected second side surface is in a stepped shape. The selected second side surface comprises at least two first sub-surfaces and at least one second sub-surface arranged alternately, and the sub-surfaces closest to the fourth surface and the second surface among the plurality of sub-surfaces are both first sub-surfaces. The at least two first sub-surfaces are parallel to the selected first side surface; and / or, the second sub-surface is parallel to the second surface.

[0009] In some embodiments, the orthographic projection of the at least two first sub-surfaces on a first reference plane has a first dimension in a first direction; the first reference plane is parallel to the selected first side surface; the first direction is the thickness direction of the substrate; and / or, the orthographic projection of the at least one second sub-surface on a second reference plane has a second dimension in a third direction; the second reference plane is parallel to the second surface; and the third direction is perpendicular to the selected first side surface.

[0010] In some embodiments, the bridge structure comprises a circuit board, the circuit board comprises a fifth surface and a sixth surface arranged oppositely, and a plurality of third side surfaces connecting the fifth surface and the sixth surface, the plurality of third side surfaces comprises at least one selected third side surface; the selected third side surface is the selected second side surface; and a plurality of back electrodes are arranged side by side and spaced apart on the sixth surface.

[0011] In some embodiments, the circuit board comprises a bonding layer and a carrier body arranged in a stack, the bonding layer is closer to the substrate than the carrier body. The selected third side surface of the circuit board is stepped, the distance between the end of the carrier body close to the selected first side surface and the selected first side surface is smaller than the distance between the end of the bonding layer close to the selected first side surface and the selected first side surface.

[0012] In some embodiments, the ratio of the thickness of the bonding layer to the thickness of the carrier body ranges from 1.4 to 1.6.

[0013] In some embodiments, the bridge structure comprises: a circuit board, a buffer structure. The circuit board comprises a fifth surface and a sixth surface arranged oppositely, and a plurality of third side surfaces connecting the fifth surface and the sixth surface, and the plurality of back electrodes are arranged in parallel and spaced apart on the sixth surface. The buffer structure is located on one side of the circuit board close to the selected first side surface; the outer surface of the buffer structure serves as at least part of the selected second side surface, and the outer surface of the buffer structure is the surface of the buffer structure away from the circuit board and the second surface.

[0014] In some embodiments, the buffer structure comprises a plurality of first sub-buffer structures, and at least a portion of each connecting lead is arranged on a first sub-buffer structure in the plurality of first sub-buffer structures.

[0015] In some embodiments, the plurality of connecting leads comprises a plurality of groups of connecting leads, each group of connecting leads comprises at least two connecting leads; the buffer structure comprises a plurality of second sub-buffer structures, and at least a portion of each group of connecting leads is arranged on a second sub-buffer structure in the plurality of second sub-buffer structures.

[0016] In some embodiments, the buffer structure extends along a second direction, the second direction is the extension direction of the intersection line of the first selected side surface and the second surface, and the length of the buffer structure is greater than the distance between the outer sides of the two connecting leads located at the outermost side in the orthogonal projection of the plurality of connecting leads on the second surface, the outer sides of the two connecting leads are the sides away from each other.

[0017] In some embodiments, the surface of the buffer structure away from the circuit board and the second surface is a straight line segment, a curved line segment or a broken line segment perpendicular to the first common edge or the second common edge, the curved line segment curves towards away from the second surface; or the surface of the buffer structure away from the circuit board and the second surface comprises a plurality of sub-surfaces connected in sequence.

[0018] In some embodiments, the buffer structure also wraps the intersection between the selected second side surface and the fourth surface.

[0019] In some embodiments, the material of the buffer structure comprises an organic material.

[0020] In some embodiments, a dimension of the portion of the connection lead on the second surface close to the end of the bridge structure in the second direction is greater than a dimension of other portions of the connection lead in the second direction; the second direction is an extension direction of the intersection line of the first selected side surface and the second surface.

[0021] In some embodiments, each back electrode comprises: a first straight line portion, an oblique line portion, and a second straight line portion. The first straight line portion extends in a direction perpendicular to the second direction; the second direction is an extension direction of the intersection line of the first selected side surface and the second surface. The oblique line portion is connected to the first straight line portion, and an extension direction of the first straight line portion intersects with an extension direction of the oblique line portion. The second straight line portion is connected to the oblique line portion and extends in a direction perpendicular to the second direction; the second straight line portion is away from the selected first side surface relative to the first straight line portion. The third portion of the connection lead is electrically connected to the first straight line portion, and the second straight line portion is used to connect the flexible printed circuit board. The first straight line portions of the plurality of back electrodes are arranged along the second direction, and the second straight line portions of the plurality of back electrodes are arranged along the second direction. A dimension of the plurality of second straight line portions along the second direction is less than a dimension of the plurality of first straight line portions along the second direction.

[0022] In another aspect, a display device is provided. The display device comprises the display panel and the driving circuit board according to any one of the above embodiments. The driving circuit board is electrically connected to the display panel; and the driving circuit board is configured to drive the display panel to display an image.

[0023] In yet another aspect, a tiled display device is provided, comprising a plurality of display devices according to any one of the above embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the present disclosure, the following will briefly introduce the drawings needed to be used in some embodiments of the present disclosure. Obviously, the drawings described in the following description are only the drawings of some embodiments of the present disclosure, and other drawings can also be obtained by those skilled in the art according to these drawings. In addition, the drawings described in the following description can be regarded as schematic diagrams, and are not limited to the actual size, actual process, actual timing of signals, etc. of the products involved in the embodiments of the present disclosure.

[0025] Figure 1 FIG. 1 is a structural diagram of a display panel according to some embodiments;

[0026] Figure 2 FIG. 2 is a structural diagram of a display panel according to some other embodiments;

[0027] Figure 3 FIG. 3 is a flowchart of a preparation process of a display panel according to some embodiments;

[0028] Figure 4 FIG. 4 is a structural diagram of a display panel according to some other embodiments;

[0029] Figure 5 A structural diagram of a display panel according to further embodiments;

[0030] Figure 6 A structural diagram of a bridge structure according to some embodiments; Figure 4 A partial enlarged view at J in the middle;

[0031] Figure 7A A structural diagram of a bridge structure according to some embodiments;

[0032] Figure 7B A structural diagram of a bridge structure according to further embodiments;

[0033] Figure 7C A structural diagram of a bridge structure according to further embodiments;

[0034] Figure 7D A structural diagram of a bridge structure according to further embodiments;

[0035] Figure 7E A structural diagram of a bridge structure according to further embodiments;

[0036] Figure 7F A structural diagram of a bridge structure according to further embodiments;

[0037] Figure 8 A structural diagram of a bridge structure according to further embodiments;

[0038] Figure 9 A structural diagram of a display panel according to further embodiments;

[0039] Figure 10 A structural diagram of a bridge structure according to further embodiments;

[0040] Figure 11 A structural diagram of a bridge structure according to further embodiments;

[0041] Figure 12 A structural diagram of a bridge structure according to further embodiments;

[0042] Figure 13A A structural diagram of a bridge structure according to some further embodiments;

[0043] Figure 13B A structural diagram of a bridge structure according to some further embodiments;

[0044] Figure 13C A structural diagram of a bridge structure according to some further embodiments;

[0045] Figure 13D A structural diagram of a bridge structure according to some further embodiments;

[0046] Figure 14 A structure diagram of a display panel according to some embodiments;

[0047] Figure 15 A structure diagram of a display panel according to some embodiments;

[0048] Figure 16 A structure diagram of a display panel according to some embodiments;

[0049] Figure 17A A structure diagram of a bridge structure according to some embodiments;

[0050] Figure 17B A structure diagram of a bridge structure according to some embodiments;

[0051] Figure 17C A structure diagram of a bridge structure according to some embodiments;

[0052] Figure 18 A structure diagram of a display panel according to some embodiments;

[0053] Figure 19 A structure diagram of a bridge structure according to some embodiments;

[0054] Figure 20 A structure diagram of a display panel according to some embodiments;

[0055] Figure 21 A structure diagram of a bridge structure according to some embodiments;

[0056] Figure 22A A structure diagram of a display device according to some embodiments;

[0057] Figure 22B A structure diagram of a display device according to some embodiments;

[0058] Figure 23 A structure diagram of a display panel according to some embodiments;

[0059] Figure 24 A structure diagram of a tiled display device according to some embodiments;

[0060] Figure 25 A structure diagram of a display panel according to some embodiments;

[0061] Figure 26 A structure diagram of a tiled display device according to some embodiments;

[0062] Figure 27 A flow chart of a manufacturing process of a display panel according to some embodiments. DETAILED DESCRIPTION

[0063] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by a person of ordinary skill in the art belong to the scope of protection of the present disclosure.

[0064] Unless otherwise required by context, the term "comprise" and its other forms such as "comprises" and "comprising" are to be construed as open, inclusive, meaning that "comprising" means "including, but not limited to." In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" and the like are intended to mean that a particular feature, structure, material or characteristic included in at least one embodiment or example of the present disclosure. The illustrative representation of the above terms does not necessarily mean the same embodiment or example. In addition, the specific features, structures, materials or characteristics described can be included in any one or more embodiments or examples in any appropriate manner.

[0065] Hereinafter, the terms "first", "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features. In the description of the embodiments of the present disclosure, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0066] In describing some embodiments, "coupled" and "connected" and their derivatives can be used. For example, the term "connected" can be used to describe some embodiments to indicate that two or more components have direct physical or electrical contact with each other. For example, the term "coupled" can be used to describe some embodiments to indicate that two or more components have direct physical or electrical contact. However, the term "coupled" or "communicatively coupled" can also mean that two or more components have no direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the content herein.

[0067] "A and / or B" includes the following three combinations: A only, B only, and both A and B.

[0068] The use of "adapted to" or "configured to" herein means an open and inclusive language that does not exclude additional devices or steps not specifically recited.

[0069] As used herein, "parallel," "perpendicular," "equal" include the recited condition and conditions approximating the recited condition within an acceptable range of deviation, where the acceptable range of deviation is determined by one of ordinary skill in the art taking into account the measurements at issue and the error associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallel and near parallel, where the acceptable range of deviation for near parallel can be, for example, within 5°; "perpendicular" includes absolute perpendicular and near perpendicular, where the acceptable range of deviation for near perpendicular can also be, for example, within 5°. "Equal" includes absolute equality and near equality, where the acceptable range of deviation for near equality can be, for example, a difference between the two that is less than or equal to 5% of either.

[0070] It will be understood that when a layer or element is referred to as being "on" another layer or substrate, it can be directly on the other layer or substrate, or intervening layers can also be present.

[0071] Exemplary embodiments are described herein with reference to cross-sectional and / or plan view illustrations that are idealized examples. In the interest of clarity, not all of the layer and regions are shown in the drawings with the same dimensions. For example, the thickness of layers and regions can be exaggerated in the drawings. Thus, the exemplary embodiments are not intended to be limited to the illustrations as shown in the drawings, but include variations as would be known to one of ordinary skill in the art. For example, the etched regions shown as rectangular can typically have curved features. Thus, the regions illustrated in the drawings are schematic and not intended to be exact representations of the regions of the device, and are not intended to limit the scope of the exemplary embodiments.

[0072] It is noted that, for example, 11-1 appearing in the drawings of the present disclosure means that the component 11 belongs to the component 1, for example, 1b-1 appearing in the drawings of the present disclosure means that the second surface 1b belongs to the substrate 1, and other similar notations appearing in the drawings of the present disclosure follow the above description. For example, 1 / 2 appearing in the drawings of the present disclosure means that the plane 1 and the plane 2 can both refer to the plane, for example, 81cc / 8cc appearing in the drawings of the present disclosure means that the selected third side surface 81cc and the selected second side surface 8cc can both be represented by the plane. Other similar notations appearing in the drawings of the present disclosure follow the above description.

[0073] To improve product reliability and reduce transportation and maintenance costs, a large-size display device can be assembled by splicing multiple small-size display devices.

[0074] To avoid the split feeling of the display screen caused by splicing, the frame size of a single small-size display device needs to be reduced, and the splicing width needs to be reduced. The small-size display device includes a display panel. For example, the wires on the display side of the display panel can be connected to the circuit board (such as a flexible circuit board) arranged on the non-display side of the display panel through side wires, so that when multiple small-size display devices are spliced to form a large-size display device, the spacing between adjacent small-size display devices can be smaller, thereby reducing the splicing width of the large-size display device formed by splicing multiple small-size display devices, and improving the display quality.

[0075] As shown in Figure 1 , Figure 2 , Figure 4 and Figure 5 , in some embodiments, the display panel 10 includes a substrate 1, a plurality of front electrodes 2, a plurality of connecting leads 3, and a plurality of back electrodes 4. The substrate 1 includes a first surface 1a and a second surface 1b arranged opposite to each other, and a plurality of first side surfaces 1c connecting the first surface 1a and the second surface 1b, at least one of the plurality of first side surfaces 1c of the substrate 1 is a selected first side surface 1cc. Each selected first side surface 1cc is provided with a plurality of connecting leads 3 arranged side by side and spaced apart; each connecting lead extends from the first surface, through the selected first side surface 1cc, to the second surface, that is, each connecting lead 3 includes a first portion 31 located on the side of the first surface 1a, a second portion 32 located on the side of the selected first side surface 1cc, and a third portion 33 located on the side of the second surface 1b.

[0076] Exemplarily, as shown in Figure 1 , the side of the first surface 1a of the substrate 1 is the front of the display panel 10, and the side of the first surface 1a of the substrate 1 is provided with a display area AA and a binding area BB. The display area AA is provided with a film layer structure such as a driving circuit layer and a light emitting device layer 5. The light emitting device layer 5 includes at least three colors of light emitting devices 51, which include at least a first color light emitting device 511, a second color light emitting device 512, and a third color light emitting device 513. The first color, the second color, and the third color are three primary colors (such as red, green, and blue). Exemplarily, the light emitting device 51 is a Micro LED (Micro Light Emitting Diode) and a Mini LED (Mini Light Emitting Diode Display).

[0077] As shown in Figure 1 and Figure 5 , the first surface 1a side of the substrate 1 is the front surface of the display panel 10, and the plurality of front surface electrodes 22 can be disposed in the bonding area BB and arranged in parallel and spaced apart along the second direction Y, which is a direction parallel to the junction line of the selected first side surface 1cc and the first surface 1a. The plurality of front surface electrodes 22 are electrically connected to at least part of the drive circuit layer (not shown in the figure). The first part 31 of the plurality of connection leads 3 is located on the first surface 1a side of the substrate 1 and electrically connected to the plurality of front surface electrodes 22 one by one. The extension direction of the first part 31 of the plurality of connection leads 3 is, for example, perpendicular to the selected first side surface 1cc of the substrate 1, that is Figure 1 the third direction Z shown in

[0078] Exemplarily, as shown in Figure 1 and Figure 5 , the second surface 1b side of the substrate 1 is the back surface of the display panel 10, and the third part 33 of the plurality of connection leads 3 is located on the second surface 1b side of the substrate 1, that is, the third part 33 of the connection lead 3 is the part of the connection lead 3 located on the back surface of the display panel 10. The extension direction of the third part 33 of the plurality of connection leads 3 is, for example, the third direction Z. The plurality of back surface electrodes 4 are disposed on the second surface 1b side of the substrate 1 and arranged in parallel and spaced apart along the second direction Y. The plurality of back surface electrodes 4 can serve as bonding electrodes for connecting the flexible circuit board 9, and the third part 33 of the plurality of connection leads 3 is electrically connected to the plurality of back surface electrodes 4 one by one.

[0079] In some examples, as shown in Figure 1 , the display panel 10 further comprises a protective layer 6 and a light blocking layer 7. The protective layer 6 covers the side surface of the connection lead 3 and is configured to provide all-round protection for the connection lead 3, so as to avoid the connection lead 3 from being in contact with air and / or water vapor and causing water and oxygen corrosion, thereby affecting the electrical conductivity of the connection lead 3. The light blocking layer 7 covers the side of the protective layer 6 away from the connection lead 3 and the side of the first surface 1a of the substrate 1. On the one hand, it is configured to prevent external light from entering the display area AA and affecting the display effect, and on the other hand, it can prevent the light emitted by the light emitting device layer 5 from leaking at the seam of the spliced display device.

[0080] The preparation method of the above-mentioned display panel 10 comprises: forming a plurality of front surface electrodes 2 and a drive circuit layer on the first surface 1a side of the substrate 1; forming a plurality of back surface electrodes 4 on the second surface 1b side of the substrate 1. The process of forming the plurality of front surface electrodes 2 and the drive circuit layer is, for example, an etching process. The process of forming the plurality of back surface electrodes 4 is, for example, laser etching.

[0081] In this case, the first surface la and the second surface lb of the substrate 1 need to be etched, resulting in high manufacturing cost of the display panel 10. Moreover, in the case where the orthogonal projection of the plurality of back electrodes 4 on the substrate 1 overlaps with the area corresponding to the display area AA, the laser light can pass through the substrate 1 to the display area AA of the first surface la, and thus part of the energy of the laser light can pass through the substrate 1 to the display area AA and damage the film layers and devices in the display area AA, resulting in reliability problems such as local corrosion and failure of the light-emitting devices to light up.

[0082] Therefore, in order to reduce the manufacturing cost of the display panel 10 while avoiding the influence of the back surface process of the substrate 1 on the front surface film layers and devices, in some embodiments, as shown in Figure 1 and Figure 4 The display panel 10 further includes a bridge structure 8 disposed on the second surface lb of the substrate 1. The bridge structure 8 includes a third surface 8a and a fourth surface 8b disposed opposite to each other, and a plurality of second side surfaces 8c connecting the third surface 8a and the fourth surface 8b. The third surface 8a is closer to the substrate 1 than the fourth surface 8b. The plurality of second side surfaces 8c includes at least one selected second side surface 8cc. Each selected second side surface 8cc corresponds to one selected first side surface lcc. The plurality of back electrodes 4 are arranged side by side on the fourth surface 8b.

[0083] Exemplarily, the thickness of the bridge structure 8 along a first direction X, which is the thickness direction of the substrate 1, is 20 μm to 200 μm.

[0084] By disposing the bridge structure 8 on the second surface lb of the substrate 1, the bridge structure 8 can serve as a carrier for the plurality of back electrodes 4. In the case where the display panel 10 includes the bridge structure 8, the plurality of back electrodes 4 can be formed by the following two steps: first, forming the plurality of back electrodes 4 on the fourth surface 8b of the bridge structure 8, and then connecting the bridge structure 8 to the second surface lb of the substrate 1 with high precision, so that the second surface lb of the substrate 1 is in contact with the third surface 8a of the bridge structure 8, and the front electrodes 2 and the back electrodes 4 are opposite to each other in the first direction X. The process of connecting the bridge structure 8 to the second surface lb of the substrate 1 with high precision is, for example, bonding. By the above method, the cost can be reduced, and the influence of the etching process on the front surface film layers and devices can be avoided.

[0085] It should be noted that the correspondence between each selected second side surface 8cc and one selected first side surface lcc means that the number of the selected second side surfaces 8cc corresponds to the number of the selected first side surfaces lcc, and the selected second side surface 8cc is closer to the selected first side surface lcc corresponding thereto, and the two are arranged along the first direction X.

[0086] It can be understood that, as shown in Figure 1 andFigure 4 As shown in FIG. 1, in the case where the display panel 10 includes the bridge structure 8, the third part 33 of the connection lead 3 includes a part 331 on the second surface lb, a part 332 on the selected second side surface 8cc, and a part 333 on the fourth surface 8b. The connection lead 3 extends from the first surface, through the selected first side surface lcc, to the edge of the second surface, and then through the second side surface 8cc to the fourth surface 8b. In this case, the part 333 of the third part 33 of the connection lead 3 on the fourth surface 8b is electrically connected to the back electrode 4 one by one.

[0087] The preparation process of the plurality of connection leads 3 is, for example, as follows: a whole-surface connection metal layer is formed on at least one selected first side surface lcc of the substrate 1, for example, by a three-dimensional sputtering process. The formed connection metal layer covers the first surface la of the substrate 1, the selected first side surface lcc of the substrate 1, and the side of the second surface lb of the substrate 1. The connection metal layer on the side of the second surface lb of the substrate 1 covers the second surface lb, the selected second side surface 8cc, and the fourth surface 8b. Then, the connection metal layer is patterned by laser etching to form a plurality of independent connection leads 3. Correspondingly, the connection metal layer on the first surface la of the substrate 1, the selected first side surface lcc of the substrate 1, and the side of the second surface lb of the substrate 1 forms the first part 31, the second part 32, and the third part 33 of the connection lead 3, respectively.

[0088] The light emitting device in the display panel 10 is, for example, a Micro LED or a Mini LED. Compared with a traditional LED, the light emitting device has a smaller particle size, i.e., a smaller volume. Therefore, under the condition that the area of the display area AA of the display panel 10 is constant, more and denser light emitting devices are installed on the display panel 10, so that the connection leads 3 of the display panel 10 are denser, which puts higher requirements on the precision and preparation speed of the preparation process of the connection leads 3. The preparation process of forming a connection metal layer and patterning by laser etching has low precision and slow preparation speed, which is not conducive to the preparation of the connection leads 3 of the Micro LED and Mini LED display panel 10.

[0089] In order to realize high-precision and fast preparation of the connection leads 3 of the Micro LED and Mini LED display panel 10, in some embodiments, the connection leads 3 are prepared by a printing process. In this case, as shown in FIG. 2, the preparation process of the display panel 10 includes the following steps: Figure 3 As shown in FIG. 2, the preparation process of the display panel 10 includes the following steps:

[0090] S1: Form a plurality of front electrodes 2 on the front surface of the initial substrate. In this step, other structures in the driving circuit layer are also formed.

[0091] S2: cutting the initial substrate to form a plurality of substrates 1, wherein a plurality of front electrodes 2 are provided on the front surface of each substrate 1.

[0092] S3: attaching the bridge structure 8 to the back surface of the substrate 1 , with a plurality of back electrodes 4 provided on the fourth surface of the bridge structure 8 , and the back electrodes 4 and the front electrodes 2 facing each other in the first direction X.

[0093] S4: Using a printing process, a conductive paste for connecting leads is formed on the front surface, the selected first side surface, the back surface, the selected second side surface and the fourth surface of the bridging structure of the substrate. The above printing process is, for example, screen printing, pad printing, transfer printing and 3D printing.

[0094] S5: curing the conductive paste to form a plurality of connecting leads 3 .

[0095] S6: forming an initial protective layer on the surfaces of the plurality of connecting leads 3 away from the substrate.

[0096] S7: Curing the initial protective layer to form a protective layer 6.

[0097] S8: Transferring the plurality of light-emitting devices to the front side of the substrate, soldering the light-emitting devices to the solder pads in the driving circuit layer, and completing the die bonding.

[0098] S9: Encapsulating a plurality of light-emitting devices.

[0099] In the manufacturing process of the display panel 10, on the one hand, when the selected second side surface 8cc of the bridge structure 8 is a plane perpendicular to the third surface 8a, in step S5, since the bridge structure 8 and the second surface 1b of the substrate 1 are stepped, the step difference from the second surface 1b directly to the fourth surface 8b is large, making it difficult for the conductive paste to climb upright on the selected second side surface 8cc, increasing the difficulty of printing and affecting the uniformity of the conductive paste leveling. As a result, the formed connecting lead 3 is prone to breakage at the boundary K between the selected second side surface 8cc and the fourth surface 8b (see FIG. 1 ). Figure 2 Furthermore, the conductive paste for the connecting leads, after being printed, undergoes two curing processes: the curing of the conductive paste for the connecting leads and the curing of the initial protective layer. These curing processes are often performed at high temperatures, requiring the material for the connecting leads 3 to undergo two high-temperature processes, making them susceptible to deformation. Furthermore, the stress at the junction K further increases the likelihood of breakage in the connecting leads 3.

[0100] Based on this, Figure 4 and Figure 5As shown, some embodiments of the present disclosure provide a display panel 10, the third surface 8a and the fourth surface 8b of the bridge structure 8 have a first interval L1. Wherein the first common edge H is the intersection line of the selected second side surface 8cc and the fourth surface 8b, the second common edge N is the intersection line of the selected second side surface 8cc and the third surface 8a, the first common edge H has a second interval L2 with the orthogonal projection of the second common edge N on the third surface 8a, and the ratio of the first interval L1 to the second interval L2 is 0.27-1.73. The distance between the second common edge N and the first selected side surface is a third interval L3, and the value of the third interval L3 is 0.5-2.0 mm.

[0101] It can be understood that the third surface 8a and the fourth surface of the bridge structure 8 have a first interval L1, which is the size of the bridge structure 8 along the first direction X, that is, the thickness of the bridge structure 8. When the orthogonal projection of the first common edge H on the third surface 8a has a second interval L2 with the orthogonal projection of the second common edge N on the third surface 8a, the second interval L2 is the size of the orthogonal projection of the selected second side surface 8cc on the third surface 8a along the third direction Z, that is, the selected second side surface 8cc is not a plane perpendicular to the third surface 8a, but a slope surface. By setting the ratio of the first interval L1 to the second interval L2 to be 0.27-1.73, the angle between the planes where the first common edge H and the second common edge N are located and the plane where the third surface 8a is located ranges from 15° to 60°; by setting in this way, the inclination of the selected second side surface 8cc is limited, so that the slope angle of the selected second side surface 8cc is 15°-60°. In this way, when the connecting lead 3 is prepared by a printing process, the conductive paste can slowly climb on the selected second side surface 8cc, which reduces the printing difficulty and improves the uniformity of the conductive paste flow, so that the subsequently formed connecting lead 3 is more reliable, and the problem of fracture of the connecting lead 3 at the junction K of the selected second side surface 8cc and the fourth surface 8b is avoided. Moreover, since the selected second side surface 8cc is a slope surface, the connecting lead 3 formed on the selected second side surface 8cc is substantially conformal to the selected second side surface 8cc, that is, the surface of the connecting lead 3 is also a slope surface. In the process of high-temperature curing of the initial connecting lead and the initial protective layer, the connecting lead 3 is not easy to deform, so as not to be easy to break.

[0102] Exemplarily, the ratio of the first interval L1 to the second interval L2 can be 0.27, 0.50, 1, 1.50, 1.73.

[0103] It can be understood that when the second common edge N is at a third interval L3 from the first selected side surface, the third interval L3 is the distance between the edge of the selected second side surface 8cc close to the selected first side surface 1cc and the selected first side surface 1cc. Through the setting of the third interval L3 in the range of 0.5mm-2.0mm, a certain gap is left between the selected second side surface 8cc and the selected first side surface 1cc in the third direction Z, so that the selected second side surface 8cc and the selected first side surface 1cc can avoid direct connection, but be connected through a part of the second surface 1b. In this way, when the connecting lead 3 is prepared by the printing process, part of the third part of the connecting lead is located on the second surface and part of it is located on the bridge structure, which increases the stability of the combination of the connecting lead and the substrate. At the same time, the connecting lead extends from the second surface to the fourth surface through the selected second side surface, which can avoid continuous climbing of the conductive paste on the selected first side surface 1cc and the selected second side surface 8cc, and the conductive paste can slowly climb on the selected second side surface 8cc and the selected first side surface 1cc. At the same time, the printing difficulty is reduced, the conductive paste is uniformly distributed, the connecting lead 3 formed subsequently is more reliable, and the risk of breaking of the connecting lead 3 is reduced. Moreover, since the connecting lead 3 formed on the selected second side surface 8cc is substantially conformal to the selected second side surface 8cc, i.e., the surface of the connecting lead 3 also presents a slope, the stress on the connecting lead 3 is more uniform, and deformation is less likely to occur during the high-temperature curing of the initial connecting lead and the high-temperature curing of the initial protective layer.

[0104] Exemplarily, the third interval L3 can be 0.5mm, 1.0mm, 1.5mm, 1.8mm, 2.0mm.

[0105] It should be noted that the third surface 8a and the fourth surface 8b can be parallel or not parallel. In the case where the third surface 8a and the fourth surface 8b are not parallel, the first interval L1 is the average interval of the third surface 8a and the fourth surface 8b. The orthogonal projection of the first common edge H on the third surface 8a and the orthogonal projection of the second common edge N on the third surface 8a can be parallel or not parallel. In the case where the orthogonal projection of the first common edge H on the third surface 8a and the orthogonal projection of the second common edge N on the third surface 8a are not parallel, the second interval L2 is the average interval of the orthogonal projection of the first common edge H on the third surface 8a and the orthogonal projection of the second common edge N on the third surface 8a. The second common edge N and the first selected side surface can be parallel or not parallel. In the case where the second common edge N and the first selected side surface are not parallel, the third interval L3 is the average interval of the second common edge N and the first selected side surface.

[0106] In some implementations, as Figure 1 and Figure 2As shown, the dimension D7 of the end portion C of the connecting lead 3 located on the second surface 1b and close to the bridge structure 8 in the second direction Y is greater than the dimension D8 of the other portion of the connecting lead 3 in the second direction Y. This is because the end portion C of the connecting lead 3 located on the second surface 1b and close to the bridge structure 8 corresponds to the position before the conductive paste climbs along the selected second side surface 8cc. It can be understood that, compared with the state when the conductive paste is printed on a plane (for example, the second plane), especially when the selected second side surface 8cc is flat, when the conductive paste is printed on the step G of the selected second side surface 8cc, climbing is more difficult and the moving speed will be slowed down, which causes a certain accumulation of the conductive paste at the position before climbing. The accumulation position corresponds to the end C of the part of the connecting lead 3 located on the second surface 1b close to the bridging structure 8, so that the dimension D7 of the end C of the part of the connecting lead 3 located on the second surface 1b close to the bridging structure 8 in the second direction Y is larger than the dimension D8 of the other parts of the connecting lead 3 in the second direction Y, resulting in low dimensional uniformity of the third part 33 of the connecting lead 3 in the direction perpendicular to its extension direction. At the same time, the thickness uniformity of the third part 33 of the connecting lead 3 is also low.

[0107] In some embodiments, as Figure 6 As shown, the portion of the connecting lead 3 located in the area corresponding to the fourth surface 8b has a first thickness d1, the portion of the connecting lead 3 in the area corresponding to the second surface 1b has a second thickness d2, and the connecting lead 3 has a third thickness d3 at the position corresponding to the selected second side surface 8cc; wherein, the first thickness d1 is greater than or equal to the second thickness d2, and the difference between the first thickness d1 and the second thickness d2 is 0 to 1 μm; the third thickness d3 is greater than the first thickness d1 or the second thickness d2, and the difference between the third thickness d3 and the first thickness d1 or the second thickness d2 is 1 μm to 3 μm.

[0108] When the difference between the first thickness d1 and the second thickness d2 is 0-1 μm, the difference between the thickness of the portion 331 of the third portion 33 of the connection lead 3 on the second surface 1b and the thickness of the portion 333 of the third portion 33 of the connection lead 3 on the side of the fourth surface 8b is less than or equal to 1 μm, so that the thickness difference between the two portions is controlled within 1 μm. Correspondingly, the portion 331 of the third portion 33 of the connection lead 3 on the second surface 1b is formed before the conductive paste climbs the selected second side surface 8cc, and the portion 333 of the third portion 33 of the connection lead 3 on the side of the fourth surface 8b is formed after the conductive paste completes the climbing of the selected second side surface 8cc. Since the selected second side surface 8cc is a slope, compared with a flat surface, the difficulty of climbing is reduced when printing the conductive paste, and the conductive paste accumulation at the position before climbing is reduced, and the thickness and size of the connection lead at the position are reduced. By such an arrangement, the thickness difference of the connection lead 3 is small at the corresponding position before the conductive paste climbs the selected second side surface 8cc and at the corresponding position after the conductive paste completes the climbing of the selected second side surface 8cc.

[0109] When the difference between the third thickness d3 and the first thickness d1 or the second thickness d2 is 1 μm-3 μm, the difference between the thickness of the portion 331 of the third portion 33 of the connection lead 3 on the second surface 1b and the thickness of the portion 332 of the third portion 33 of the connection lead 3 on the selected second side surface 8cc, and the difference between the thickness of the portion 333 of the third portion 33 of the connection lead 3 on the side of the fourth surface 8b and the thickness of the portion 332 of the third portion 33 of the connection lead 3 on the selected second side surface 8cc are all less than or equal to 3 μm, so that the thickness difference between any two of the portion 331 of the third portion 33 of the connection lead 3 on the second surface 1b, the portion 332 of the third portion 33 of the connection lead 3 on the selected second side surface 8cc and the portion 333 of the third portion 33 of the connection lead 3 on the side of the fourth surface 8b is controlled within 3 μm. By such an arrangement, the overall thickness difference of the third portion 33 of the connection lead 3 is small, so that the thickness uniformity of the third portion 33 of the connection lead 3 is improved, the size difference between the end portion of the portion of the connection lead 3 on the second surface 1b close to the bridge structure 8 and other portions of the connection lead 3 is reduced, and the risk of fracture of the connection lead 3 is reduced.

[0110] Exemplarily, the first thickness d1 can be 2 μm, 2.5 μm, 2.7 μm, 3 μm.

[0111] Exemplarily, the second thickness d2 can be 2 μm, 2.2 μm, 2.5 μm, 3 μm.

[0112] Exemplarily, the third thickness d3 can be 3 μm, 3.7 μm, 4.0 μm, 4.5 μm, 5 μm.

[0113] The above-mentioned third thickness d3 is greater than the first thickness d1 or the second thickness d2. This is because when the connecting lead 3 is prepared by printing, it is necessary to print and lift the needle at the position corresponding to the selected second side surface 8cc. The moving speed of the conductive paste is slowed down, causing the conductive paste to accumulate, and the actual measured thickness of the connecting lead 3 is high at the position corresponding to the selected second side surface 8cc.

[0114] For example, the difference between the first thickness d1 and the second thickness d2 may be 0 μm, 0.1 μm, 0.5 μm, or 1 μm.

[0115] For example, the difference between the third thickness d3 and the first thickness d1 may be 1 μm, 1.5 μm, 2.0 μm, 2.5 μm, 2.7 μm, or 3.0 μm, and the difference between the third thickness d3 and the second thickness d2 may be 1 μm, 1.8 μm, 2.0 μm, 2.5 μm, or 3.0 μm.

[0116] It should be noted that the first thickness d1 is the average thickness of each portion of the connecting lead 3 located in the region corresponding to the fourth surface 8b, that is, the average thickness of the portion 333 of the third portion 33 of the connecting lead 3 located on the fourth surface 8b side. Furthermore, the direction of the first thickness d1 is the first direction X, which is perpendicular to the fourth surface 8b. The second thickness d2 is the average thickness of each portion of the connecting lead 3 located in the region corresponding to the second surface 1b, that is, the average thickness of the portion 331 of the third portion 33 of the connecting lead 3 located on the second surface 1b. Furthermore, the direction of the second thickness d2 is the first direction X, which is perpendicular to the second surface 1b. The third thickness d3 is the average thickness of each portion of the connecting lead 3 located in the region corresponding to the selected second side surface 8cc, that is, the average thickness of the portion 332 of the third portion 33 of the connecting lead 3 located on the selected second side surface 8cc. Furthermore, the direction of the third thickness d3 is perpendicular to the selected second side surface 8cc.

[0117] In some embodiments, as Figures 7A-7F As shown, a cross section of the selected second side surface 8cc perpendicular to the first common edge H or the second common edge N is a straight line segment, a curved line segment or a broken line segment, and the curved line segment bends away from the second surface 1b.

[0118] like Figure 7A As shown, when the cross-section of the second side surface 8cc perpendicular to the first common edge H or the second common edge N is selected as a straight line segment, the second side surface 8cc is selected as an inclined plane. Compared with the case where the second side surface 8cc is selected to be perpendicular to the third surface 8a, the uniformity of the leveling of the conductive paste is improved when preparing the connecting lead 3 through the printing process, and the formed connecting lead 3 is more reliable.

[0119] like Figure 7BAs shown in FIG. 6, when the cross section of the selected second side surface 8cc perpendicular to the first common edge H or the second common edge N is a curved segment, the selected second side surface 8cc is an inclined curved surface. Compared with the case that the selected second side surface 8cc is perpendicular to the third surface 8a, the uniformity of the conductive paste flow is improved when the connecting lead 3 is prepared by the printing process, and the formed connecting lead 3 is more reliable. Moreover, the curved segment is curved away from the second surface 1b, that is, the selected second side surface is an outward convex curved surface. By arranging the curved segment to be curved away from the second surface 1b, a relatively upright slope is avoided to be formed on the selected second side surface 8cc near the fourth surface 8b, and the problem that the conductive paste is difficult to climb the upright slope when the initial connecting lead is printed is avoided.

[0120] It should be noted that when the cross section of the selected second side surface 8cc perpendicular to the first common edge H or the second common edge N is a curved segment, the number of the curved segments can be one or multiple, which is not limited herein. In the case that the curved segments include multiple curved segments, the multiple curved segments are sequentially connected and the whole is inclined.

[0121] As shown in FIG. 7, when the cross section of the selected second side surface 8cc perpendicular to the first common edge H or the second common edge N is a polyline segment, the selected second side surface 8cc is overall sawtooth-shaped. Compared with the case that the selected second side surface 8cc is perpendicular to the third surface 8a, the uniformity of the conductive paste flow is improved when the connecting lead 3 is prepared by the printing process, and the formed connecting lead 3 is more reliable. Figures 7C-7F In some embodiments, as shown in FIG. 8, the selected second side surface 8cc is a plane, and the included angle between the selected second side surface 8cc and the third surface 8a ranges from 10° to 80°.

[0122] Figure 7A When the included angle a between the selected second side surface 8cc and the third surface 8a ranges from 10° to 80°, the included angle b between the selected second side surface 8cc and the fourth surface 8b ranges from 100° to 170°. In this way, the conductive paste can be kept in a slow climbing state on the selected second side surface 8cc when the connecting lead 3 is prepared by the printing process.

[0123] By arranging the included angle a between the selected second side surface 8cc and the third surface 8a to be less than or equal to 80°, the included angle a between the selected second side surface 8cc and the third surface 8a is not too large, so that a relatively upright slope is avoided to be formed, and the problem that the conductive paste is difficult to climb the upright slope when the initial connecting lead is printed is avoided. By arranging the included angle a between the selected second side surface 8cc and the third surface 8a to be greater than or equal to 10°, the included angle a between the selected second side surface 8cc and the third surface 8a is not too small, which is beneficial to ensure the third interval L3.

[0124] By arranging the included angle a between the selected second side surface 8cc and the third surface 8a to be less than or equal to 80°, the included angle a between the selected second side surface 8cc and the third surface 8a is not too large, so that a relatively upright slope is avoided to be formed, and the problem that the conductive paste is difficult to climb the upright slope when the initial connecting lead is printed is avoided. By arranging the included angle a between the selected second side surface 8cc and the third surface 8a to be greater than or equal to 10°, the included angle a between the selected second side surface 8cc and the third surface 8a is not too small, which is beneficial to ensure the third interval L3. ​

[0125] For example, the selected second side surface 8cc and the third surface 8a can form an angle a of 10°, 20°, 30°, 40°, 45°, 60°, 80°.

[0126] In some embodiments, as shown in Figure 7D the selected second side surface 8cc comprises a plurality of sub-surfaces 8cc1 connected in sequence; of the two adjacent sub-surfaces 8cc1, the sub-surface 8cc1 farther away from the selected first side surface 1cc is relatively farther away from the second surface 1b than the other sub-surface 8cc1.

[0127] By such arrangement, the two adjacent sub-surfaces 8cc1 can be arranged in a direction from the second common edge N to the first common edge H, and the arrangement direction forms an angle with the third plane of the bridge structure 8 smaller than 90°. In this way, when the connecting lead 3 is prepared by printing process, the conductive paste can slowly climb on the selected second side surface 8cc, which reduces the printing difficulty and improves the flow leveling of the conductive paste, so that the subsequently formed connecting lead 3 is more reliable, and the problem of fracture of the connecting lead 3 at the junction K of the selected second side surface 8cc and the fourth surface 8b (see the crack of the connecting lead in Figure 2 ) is avoided. Moreover, since the connecting lead 3 formed on the selected second side surface 8cc is substantially conformal to the selected second side surface 8cc, that is, the surface of the connecting lead 3 also presents a slope, the connecting lead 3 is not prone to deformation during the high-temperature curing of the initial connecting lead and the high-temperature curing of the initial protective layer.

[0128] It should be noted that, of the two adjacent sub-surfaces 8cc1, the sub-surface 8cc1 farther away from the selected first side surface 1cc is relatively farther away from the second surface 1b than the other sub-surface 8cc1, which means that the sub-surface 8cc1 farther away from the selected first side surface 1cc and the sub-surface 8cc1 farther away from the second surface 1b are the same sub-surface 8cc1. Hereinafter, the sub-surface 8cc1A and the sub-surface 8cc1B of the selected second side surface 8cc are taken as examples for specific description. As shown in Figure 7D of the selected second side surface 8cc, the sub-surface 8cc1A is the sub-surface 8cc1 farther away from the selected first side surface 1cc, and at the same time, the sub-surface 8cc1A is the sub-surface 8cc1 farther away from the second surface 1b.

[0129] Exemplarily, the plurality of sub-surfaces 8cc1 are all curved surfaces, or the plurality of sub-surfaces 8cc1 are all planar surfaces, or some of the plurality of sub-surfaces 8cc1 are curved surfaces and the rest of the plurality of sub-surfaces 8cc1 are planar surfaces. When some of the plurality of sub-surfaces 8cc1 are curved surfaces and the rest of the plurality of sub-surfaces 8cc1 are planar surfaces, the arrangement of the planar sub-surfaces 8cc1 and the curved sub-surfaces 8cc1 is not limited.

[0130] In some embodiments, as shown in FIG. 1, the plurality of sub-surfaces 8cc1 are planar surfaces, and the selected second side surface 8cc is in the form of a stepped surface. The selected second side surface 8cc comprises at least two first sub-surfaces 8cc1a and at least one second sub-surface 8cc1b arranged alternately, and the sub-surfaces 8cc1 closest to the fourth surface 8b and the second surface 1b among the plurality of sub-surfaces 8cc1 are all first sub-surfaces 8cc1a. The at least two first sub-surfaces 8cc1a are parallel to the selected first side surface 1cc; and / or, the second sub-surface 8cc1b is parallel to the second surface 1b. Figures 7D-7F

[0131] Figures 7D-7F Exemplarily, when the plurality of sub-surfaces 8cc1 are planar surfaces and the selected second side surface 8cc is in the form of a stepped surface, the selected second side surface 8cc comprises at least two connecting surfaces and at least one stepped surface, the first sub-surfaces 8cc1a are the connecting surfaces, and the second sub-surfaces 8cc1b are the stepped surfaces. The sub-surfaces 8cc1 adjacent to the fourth surface 8b or the second surface 1b among the plurality of sub-surfaces 8cc1 are all first sub-surfaces 8cc1a, as shown in FIG. 1. Figure 7D Figure 7E When the at least two first sub-surfaces 8cc1a are parallel to the selected first side surface 1cc, the connecting surfaces are perpendicular to the third surface 8a, and the second sub-surfaces 8cc1b are not limited and can be parallel to the second surface 1b or not, as shown in FIG. 1. Figure 7D Figure 7F When the second sub-surfaces 8cc1b are parallel to the second surface 1b, the stepped surfaces are parallel to the third surface 8a, and the first sub-surfaces 8cc1a are not limited and can be parallel to the selected first side surface 1cc or not, as shown in FIG. 1.

[0132] ​​​​By selecting the stepped arrangement of the second side surface 8cc, compared with the case that the second side surface 8cc is a flat surface parallel to the third surface 8a, the vertical climbing state of the conductive paste on the selected second side surface 8cc is changed to a segmented climbing state when the connecting lead 3 is prepared by a printing process, which reduces the printing difficulty and improves the uniformity of the conductive paste flow, so that the subsequently formed connecting lead 3 is more reliable, and the problem of fracture of the connecting lead 3 at the junction K of the selected second side surface 8cc and the fourth surface 8b is avoided. Moreover, since the connecting lead 3 formed on the selected second side surface 8cc is substantially conformal to the selected second side surface 8cc, that is, the surface of the connecting lead 3 also presents a slope, the connecting lead 3 is not prone to deformation during the high-temperature curing of the initial connecting lead and the high-temperature curing of the initial protective layer.

[0133] In some embodiments, as shown in FIG. 1A, the size of the normal projection of the at least two first sub-surfaces 8cc1a on the first reference plane in the first direction X is a first size D1; the first reference plane is parallel to the selected first side surface 1cc; and the first direction X is the thickness direction of the substrate 1. Figures 7D-7F

[0134] By such an arrangement, the selected second side surface 8cc is a plurality of connecting surfaces with the same height, and the first interval L1 with a large difference is divided into a plurality of smaller differences in the first direction X. In this way, when the connecting lead 3 is prepared by a printing process, the uniformity of the conductive paste flow on the selected second side surface 8cc is improved, which reduces the printing difficulty and improves the uniformity of the conductive paste flow.

[0135] In some embodiments, as shown in FIG. 1A, the size of the normal projection of the at least two first sub-surfaces 8cc1a on the first reference plane in the first direction X is a first size D1; the first reference plane is parallel to the selected first side surface 1cc; and the first direction X is the thickness direction of the substrate 1. Figures 7D-7F

[0136] In this way, the normal projections of the adjacent two second sub-surfaces 8cc1b of the selected second side surface 8cc on the third surface 8a do not overlap with each other, and the normal projections of the adjacent two second sub-surfaces 8cc1b on the plane parallel to the selected first side surface 1cc are arranged at equal intervals, and the second interval L2 is divided into a plurality of parts with the same size in the third direction Z. In this way, when the connecting lead 3 is prepared by a printing process, the uniformity of the conductive paste flow on the selected second side surface 8cc is improved.

[0137] In some embodiments, as shown in FIG. 1A, the size of the normal projection of the at least two first sub-surfaces 8cc1a on the first reference plane in the first direction X is a first size D1; the first reference plane is parallel to the selected first side surface 1cc; and the first direction X is the thickness direction of the substrate 1. Figure 7D ​​As shown, the orthographic projections of the at least two first sub-surfaces 8cc1a on the first reference plane all have a first dimension D1 in the first direction X. Also, the orthographic projections of the at least one second sub-surface 8cc1b on the second reference plane all have a second dimension D2 in the third direction Z. Moreover, the first dimension D1 and the second dimension D2 are equal.

[0138] By so doing, the selected second side surface 8cc is divided into steps of equal size, and the connecting surfaces are also of equal size. The first interval L1 with a large step difference is divided into a plurality of intervals with small step differences in the first direction X, and the second interval L2 is divided into a plurality of intervals of uniform size in the third direction Z. In this way, when the connecting leads 3 are prepared by printing, the conductive paste flows evenly on the selected second side surface 8cc.

[0139] The composition of the bridge structure and the specific implementation of the selected second side surface being a sloping surface are described below.

[0140] In some embodiments, as shown in Figure 8 The bridge structure 8 includes a circuit board 81, which includes a fifth surface 81a and a sixth surface 81b arranged opposite to each other, and a plurality of third side surfaces 81c connecting the fifth surface 81a and the sixth surface 81b, the plurality of third side surfaces 81c including at least one selected third side surface 81cc; the selected third side surface 81cc is the selected second side surface 8cc; and a plurality of back electrodes 4 arranged side by side and spaced apart on the sixth surface 81b.

[0141] In the case where the bridge structure 8 includes the circuit board 81, the fifth surface 81a of the circuit board 81 is the third surface 8a of the bridge structure 8; and the sixth surface 81b of the circuit board 81 is the fourth surface 8b of the bridge structure 8. At this time, the circuit board 81 can serve as a carrier for the plurality of back electrodes 4.

[0142] In some embodiments, as shown in Figure 8 and Figure 9 The circuit board 81 includes a bonding layer 811 and a carrier body 812 arranged in a stack, the bonding layer 811 being closer to the substrate 1 than the carrier body 812. As shown in Figure 8 The bonding layer 811 and the carrier body 812 are cut so that the side of the bonding layer 811 and the carrier body 812 closer to the selected first side surface is a bevel, i.e., the selected third side surface 81cc of the circuit board 81 is a bevel, so as to realize that the first common edge H of the selected third side surface 81cc of the circuit board 81 is farther away from the selected first side surface 81cc than the second common edge N, and the orthographic projections of the two on the second surface of the substrate have a second interval.

[0143] As shown in Figure 9As shown, the selected third side surface 81cc of the circuit board 81 is stepped, and the distance D4 between the end of the carrier body 812 close to the selected first side surface 1cc and the selected first side surface 1cc is less than the distance D3 between the end of the adhesive layer 811 close to the selected first side surface 1cc and the selected first side surface 1cc.

[0144] The carrier body 812 is a part of the circuit board 81 that serves as a carrier of the plurality of back electrodes 4, and the adhesive layer 811 is used to connect the carrier body 812 and the back plate. It can be understood that the adhesive layer 811 is closer to the substrate 1 relative to the carrier body 812, and can achieve the function of connecting the carrier body 812 and the back plate. By setting the distance D4 between the end of the carrier body 812 close to the selected first side surface 1cc and the selected first side surface 1cc to be less than the distance D3 between the end of the adhesive layer 811 close to the selected first side surface 1cc and the selected first side surface 1cc, the selected third side surface 81cc of the circuit board 81 is formed to be stepped, and the ratio of the first interval L1 to the second interval L2 can be 0.27-1.73, so that when the connecting lead 3 is prepared by a printing process, the conductive paste can slowly climb on the selected third side surface 81cc, which reduces the printing difficulty and makes the conductive paste more evenly distributed.

[0145] As shown in the example, Figure 9 In the case where the selected third side surface 81cc of the circuit board 81 is stepped, the number of the first sub-surfaces 8cc1 can be two, the end surface 811a of the adhesive layer 811 close to the selected first side surface 1cc serves as the first sub-surface 8cc1a close to the substrate 1, and the end surface 812a of the carrier body 812 close to the selected first side surface 1cc serves as the first sub-surface 8cc1a away from the substrate 1. The end surface 811a of the adhesive layer 811 close to the selected first side surface 1cc, the end surface 812a of the carrier body 812 close to the selected first side surface 1cc, and the second sub-surface 8cc1b therebetween together form the selected second side surface 8cc.

[0146] By such a setting, the carrier body 812 and the adhesive layer 811 can be cut in multiple times, and the cutting line of the adhesive layer 811 is closer to the selected first side surface 1cc relative to the cutting line of the carrier body 812, thereby forming the stepped selected third side surface 81cc, which simplifies the forming method of the selected third side surface 81cc of the circuit board 81.

[0147] As an example, the material of the carrier body is polyimide. The polyimide material has high precision, high temperature resistance, low expansion, and other characteristics, so that the carrier body is not easy to displace in subsequent high temperature processes, such as reflow soldering.

[0148] In some embodiments, asFigure 9 As shown, the thickness d3 of the adhesive layer 811 is greater than the thickness d4 of the carrier body 812.

[0149] By such arrangement, the connection firmness of the carrier body and the substrate 1 can be increased, and the positional accuracy of the back electrode 4 can be prevented from being affected by the movement of the carrier body 812 in the subsequent process of the display panel 10.

[0150] In some embodiments, as shown in Figure 9 As shown, the ratio of the thickness d3 of the adhesive layer 811 to the thickness d4 of the carrier body 812 ranges from 1.4 to 1.6.

[0151] It can be understood that when the difference between the thickness d3 of the adhesive layer 811 and the thickness d4 of the carrier body 812 is too large, the thickness of the thicker one of the adhesive layer 811 and the carrier body 812 will be close to the thickness of the circuit board 8, so that even if the selected second side surface 8cc is formed in a stepped manner, the step difference of the selected second side surface 8cc is still large, and the purpose of slowly climbing the conductive paste on the selected second side surface 8cc cannot be achieved. By setting the ratio of the thickness d3 of the adhesive layer 811 to the thickness d4 of the carrier body 812 to range from 1.4 to 1.6, the difference between the thickness d3 of the adhesive layer 811 and the thickness d4 of the carrier body 812 will not be too large, and the selected second side surface 8cc can be formed in a stepped manner. Compared to the case where the selected second side surface 8cc is a flat surface of the vertical third surface 8a, the uniformity of the conductive paste flow is improved when the connecting lead 3 is prepared by the printing process, the connecting lead 3 formed is more reliable, the printing difficulty is reduced, and the conductive paste is uniformly distributed. Exemplarily, the ratio of the thickness d3 of the adhesive layer 811 to the thickness d4 of the carrier body 812 can be 1.4, 1.5, or 1.6.

[0152] In order to increase the feasibility of the high-precision attachment of the circuit board 81 to the second surface 1b of the substrate 1, in some examples, as shown in Figure 10 and Figure 11 As shown, before the circuit board 81 is attached to the second surface 1b of the substrate 1, the side of the adhesive layer 811 away from the carrier body 812 is provided with a release film E, and the side of the carrier body 812 away from the adhesive layer 811 is provided with a reinforcing film F. The release film E can prevent the adhesive layer 811 from adhering to other foreign matters before the circuit board 81 is attached, thereby affecting the adhesion performance. The reinforcing film F can increase the strength of the carrier body 812, so as to avoid the curling or bending of the carrier body during the attachment of the circuit board 81, thereby affecting the attachment. It should be noted that the release film E needs to be removed before the circuit board 81 is attached, and the reinforcing film F needs to be removed after the circuit board 81 is attached.

[0153] The above embodiments are to improve the structure of the circuit board 81 itself to form the inclined selected second side surface of the bridge structure. Another implementation manner is described below.

[0154] In some embodiments, as shown in Figure 12 The bridge structure 8 includes the circuit board 81 and the buffer structure 82. The circuit board 81 includes the fifth surface 81a and the sixth surface 81b arranged oppositely, and the plurality of third side surfaces 81c connecting the fifth surface 81a and the sixth surface 81b. The plurality of back electrodes 4 are arranged in parallel and spaced apart on the sixth surface 81b. The buffer structure 82 is located on the side of the circuit board 81 close to the selected first side surface 1cc. The outer surface 82a of the buffer structure 82 serves as at least part of the selected second side surface 8cc. The outer surface 82a of the buffer structure 82 is the surface of the buffer structure 82 away from the circuit board 81 and the second surface 1b.

[0155] It should be noted that the outer surface 82a of the buffer structure 82, which is the surface of the buffer structure 82 away from the circuit board 81 and the second surface 1b, means that as shown in Figure 12 The surface of the buffer structure 82 can be divided into three parts. The first part is the first inner surface 82b of the buffer structure 82 in contact with the circuit board 81. The second part is the second inner surface 82c of the buffer structure 82 in contact with the second surface 1b of the substrate 1. The third part is the outer surface 82a of the buffer structure, that is Figure 12 the part indicated by the dashed rectangle.

[0156] The above buffer structure 82 is located on the side of the circuit board 81 close to the selected first side surface 1cc. By arranging the buffer structure 82 on the side of the circuit board close to the selected first side surface 1cc, the outer surface 82a of the buffer structure serves as at least part of the selected second side surface 8cc. Therefore, the junction edge between the outer surface 82a of the buffer structure and the second inner surface 82c serves as the second common edge N, and the first common edge H is the junction edge between the sixth surface 81b of the circuit board 81 and the selected third side surface 81cc. Compared with the case without the buffer structure 82, the second common edge N is farther away from the first common edge H, which is conducive to forming the second interval L2 between the second common edge N and the first common edge H, so that the selected second side surface 8cc is a slope surface. The uniformity of the conductive paste flow during the preparation of the connecting lead 3 by the printing process is improved, and the connecting lead 3 formed is more reliable.

[0157] The outer surface 82a of the buffer structure serves as at least part of the selected second side surface 8cc. Therefore, during the preparation of the connecting lead 3 by the printing process, the conductive paste can slowly climb the slope on the outer surface 82a of the buffer structure.

[0158] The bridge structure 8 includes: a circuit board 81, a buffer structure 82, an outer surface 82a of the buffer structure 82 serving as at least a portion of the selected second side surface 8cc, and at least four cases as follows:

[0159] The first case: as shown in Figure 12 and Figure 13A , the side surface of the circuit board 81 close to the selected first side surface 1cc is a plane perpendicular to the third surface 8a. The buffer structure 82 is located on the side of the circuit board 81 close to the selected first side surface 1cc, and the size d7 of the buffer structure 82 along the first direction X is less than the thickness d5 of the circuit board 81. In this case, the side surface 81c of the circuit board 81 close to the selected first side surface 1cc and the outer surface 82a of the buffer structure 82 together constitute the selected second side surface 8cc. By arranging the buffer structure 82, the slope of the portion of the selected second side surface 8cc close to the second surface 1b of the substrate 1 is reduced.

[0160] The second case: as shown in Figure 12 and Figure 13B , the side surface of the circuit board 81 close to the selected first side surface 1cc is a plane perpendicular to the third surface 8a. The buffer structure 82 is located on the side of the circuit board 81 close to the selected first side surface 1cc, and the size d5 of the buffer structure 82 along the first direction X is greater than or equal to the thickness d7 of the circuit board 81. In this case, the outer surface 82a of the buffer structure 82 is the selected second side surface 8cc. By arranging the buffer structure 82, the overall slope of the selected second side surface 8cc is reduced.

[0161] The third case: as shown in Figure 12 and Figure 13C , the circuit board 81 includes oppositely arranged fifth surface 81a and sixth surface 81b, and a plurality of third side surfaces 81c connecting the fifth surface 81a and the sixth surface 81b, the plurality of third side surfaces 81c including at least one selected third side surface 81cc; the cross section of the selected third side surface 81cc perpendicular to the first common edge H or the second common edge N is a straight line segment, a curve segment or a polyline segment, the curve segment bends away from the second surface 1b; or, the selected third side surface 81cc includes a plurality of sub-surfaces 8cc1 connected in sequence. The buffer structure 82 is located on the side of the circuit board 81 close to the selected first side surface 1cc. Moreover, the size d7 of the buffer structure 82 along the first direction X is less than the thickness d5 of the circuit board 81. In this case, the selected third side surface 81cc and the outer surface 82a of the buffer structure 82 together constitute the selected second side surface 8cc, and the overall slope of the selected second side surface 8cc is reduced. Among them, by selecting the third side surface 81cc, the slope of the portion of the selected second side surface 8cc away from the second surface 1b of the substrate 1 is reduced, and by arranging the buffer structure 82, the slope of the portion of the selected second side surface 8cc close to the second surface 1b of the substrate 1 is reduced.

[0162] The fourth case: as shown in Figure 12 and Figure 13D , the circuit board 81 includes a fifth surface 81a and a sixth surface 81b arranged opposite to each other, and a plurality of third side surfaces 81c connecting the fifth surface 81a and the sixth surface 81b, the plurality of third side surfaces 81c including at least one selected third side surface 81cc; the selected third side surface 81cc is a straight line segment, a curved line segment or a broken line segment in the cross section perpendicular to the first common edge H or the second common edge N, and the curved line segment is curved towards away from the second surface 1b; or, the selected third side surface 81cc includes a plurality of sub-surfaces 8cc1 connected in sequence. The buffer structure 82 is located on the side of the circuit board 81 close to the selected first side surface 1cc. Moreover, the size d5 of the buffer structure 82 along the first direction X is greater than or equal to the thickness d7 of the circuit board 81. In this case, the outer surface 82a of the buffer structure is the selected second side surface 8cc. In this way, by selecting the third side surface 81cc, the slope of the selected second side surface 8cc is slowed down, and by setting the buffer structure 82, the slope of the selected second side surface 8cc is further slowed down. Among them, the third case and the fourth case are the implementation mode of combining the improvement of the structure of the circuit board itself and the setting of the buffer structure.

[0163] In some embodiments, as shown in Figure 14 , the buffer structure 82 includes a plurality of first sub-buffer structures 821, and at least a part of each connection lead 3 is arranged on a first sub-buffer structure 821 in the plurality of first sub-buffer structures 821.

[0164] In this case, the number of the plurality of first sub-buffer structures 821 is consistent with the number of the plurality of connection leads 3, and the plurality of first sub-buffer structures 821 are arranged along the second direction Y, which is equivalent to forming a plurality of arc island-shaped buffer blocks on the side surface of the circuit board 81. In this way, when the connection lead 3 is prepared by printing process, the conductive paste forming each connection lead 3 can slowly climb along the outer surface of the corresponding first sub-buffer structure 821. It should be noted that the description of the outer surface of the first sub-buffer structure 821 is described in the foregoing description of the outer surface 82a of the buffer structure, and will not be described again.

[0165] In some embodiments, as shown in Figure 15 , the plurality of connection leads 3 includes a plurality of groups of connection leads 3, each group of connection leads 3 including at least two connection leads 3; the buffer structure 82 includes a plurality of second sub-buffer structures 822, and at least a part of each group of connection leads 3 is arranged on a second sub-buffer structure 822 in the plurality of second sub-buffer structures 822.

[0166] In this case, the number of the plurality of second sub-buffer structures 822 is consistent with the number of the plurality of groups of connection leads 3, and the plurality of first sub-buffer structures 821 are arranged along the second direction Y, which is equivalent to forming a plurality of groups of buffer strips on the side surface of the circuit board 81. In this way, when the connection leads 3 are prepared by a printing process, the conductive paste forming each group of connection leads 3 can slowly climb up along the outer surface of the corresponding second sub-buffer structure 822. It should be noted that the description of the outer surface of the second sub-buffer structure 822 can refer to the foregoing description of the outer surface 82a of the buffer structure, and will not be repeated here.

[0167] For example, as shown in FIG. 8, each group of connection leads 3 includes three connection leads 3. Figure 15

[0168] In some embodiments, as shown in FIG. 8, the buffer structure 82 extends along the second direction Y, which is the extension direction of the intersection line of the selected first side surface 1cc and the second surface 1b, and the length D5 of the buffer structure 82 is greater than the distance D6 between the outer sides P of the two connection leads 3 located at the outermost sides in the orthogonal projection of the plurality of connection leads 3 on the second surface 1b, the outer sides P of the two connection leads 3 being the sides away from each other. Figure 16 By such an arrangement, it is equivalent to forming a whole strip-shaped buffer layer on the side surface of the circuit board 81, which simplifies the preparation process of the buffer structure 82, and at the same time, each connection lead 3 away from the selected first side surface 1cc is provided with a part of the buffer structure 82. In this way, when the connection leads 3 are prepared by a printing process, each connection lead 3 can slowly climb up along a part of the outer surface 82a of the buffer structure.

[0169] In some embodiments, as shown in FIG. 8, the cross section of the buffer structure 82 away from the surface of the circuit board 81 and the second surface 1b perpendicular to the first common edge H or the second common edge N is a straight line segment, a curved line segment or a polyline segment, the curved line segment curves towards away from the second surface 1b; or the surface of the buffer structure 82 away from the surface of the circuit board 81 and the second surface 1b includes a plurality of sub-surfaces 82a1 connected in sequence.

[0170] Figures 17A-17C The surface of the above-mentioned buffer structure 82 away from the surface of the circuit board 81 and the second surface 1b is the outer surface 82a of the buffer structure. In the case that the outer surface 82a of the buffer structure is at least part of the selected second side surface 8cc, by the above-mentioned arrangement, the slope on the outer surface 82a of the buffer structure is slowed down, that is, the slope of at least part of the selected second side surface 8cc is slowed down, and when the connection leads 3 are prepared by a printing process, the conductive paste slowly climbs up on the outer surface 82a of the buffer structure.

[0171] The surface of the above-mentioned buffer structure 82 away from the surface of the circuit board 81 and the second surface 1b is the outer surface 82a of the buffer structure. In the case that the outer surface 82a of the buffer structure is at least part of the selected second side surface 8cc, by the above-mentioned arrangement, the slope on the outer surface 82a of the buffer structure is slowed down, that is, the slope of at least part of the selected second side surface 8cc is slowed down, and when the connection leads 3 are prepared by a printing process, the conductive paste slowly climbs up on the outer surface 82a of the buffer structure.

[0172] ​​In some embodiments, as shown in Figure 18 and Figure 19 the buffer structure 82 extends along the second direction Y, the second direction Y being the extending direction of the junction line of the selected first side surface 1cc and the second surface 1b, and the length D5 of the buffer structure 82 is greater than the distance D6 between the outer sides P of the two connection leads 3 located at the outermost of the plurality of connection leads 3 in the orthographic projection of the second surface 1b, the outer sides P of the two connection leads 3 being the sides of the two connection leads 3 away from each other. Moreover, the buffer structure 82 comprises a plurality of third sub-buffer structures 823 arranged along the first direction X and having the same size along the second direction Y, the plurality of third sub-buffer structures 823 being such that the buffer structure outer surface 82a is stepped.

[0173] By such arrangement, the step difference on the buffer structure outer surface 82a is reduced, the first interval L1 with larger step difference is decomposed into a plurality of smaller step differences along the first direction X, and the second interval L2 is divided into a plurality of segments along the third direction Z. In this way, the flow leveling of the conductive paste on the selected second side surface 8cc when preparing the connection leads 3 by printing process is improved; and the buffer structure 82 as a whole is a strip structure, and the preparation process is simple.

[0174] Exemplarily, as shown in Figure 18 and Figure 19 the number of the plurality of third sub-buffer structures 823 is four, which are the third sub-buffer structure 823a, the third sub-buffer structure 823b, the third sub-buffer structure 823c and the third sub-buffer structure 823d, as shown in Figure 19 the thickness d5 of the circuit board 81 along the first direction X is 0.1 mm, and the thickness of the plurality of third sub-buffer structures 823 along the first direction X is equal, for example, the thickness d6 of each third sub-buffer structure 823 along the first direction X is 20 pm. By such arrangement, the step difference between adjacent step surfaces of the buffer structure outer surface 82a is more uniform, and the flow leveling of the conductive paste on the selected second side surface 8cc when preparing the connection leads 3 by printing process is improved, and the subsequently formed connection leads 3 will not be broken due to large step difference.

[0175] In some embodiments, as shown in Figure 13B , Figure 13D and Figure 17B the junction T between the side surface 81c of the circuit board 81 close to the selected first side surface 1cc and the sixth surface 81b of the circuit board 81.

[0176] Since the intersection between the side surface 81c of the circuit board 81 close to the selected first side surface 1cc and the sixth surface 81b of the circuit board 81 is relatively sharp, the conductive paste is subjected to a relatively large force at this position, and is prone to deformation during the high-temperature curing of the initial connecting lead and the high-temperature curing of the initial protective layer, thereby increasing the possibility of breakage of the connecting lead 3. Based on this, by wrapping the buffer structure 82 around the intersection T between the side surface 81c of the circuit board 81 close to the selected first side surface 1cc and the sixth surface 81b of the circuit board 81, when the connecting lead 3 is prepared by the printing process, the conductive paste forming the connecting lead 3 can bypass the intersection between the side surface 81c of the circuit board 81 close to the selected first side surface 1cc and the sixth surface 81b of the circuit board 81 to reach the sixth surface 81b to connect with the back electrode 4, thereby achieving a smooth transition and reducing the risk of breakage of the conductive paste at the intersection between the side surface 81c of the circuit board 81 close to the selected first side surface 1cc and the sixth surface 81b of the circuit board 81.

[0177] It can be understood that when the buffer structure 82 wraps the intersection T between the side surface 81c of the circuit board 81 close to the selected first side surface 1cc and the sixth surface 81b of the circuit board 81, the dimension d7 of the buffer structure 82 along the first direction X is greater than or equal to the thickness d5 of the circuit board 81, corresponding to the second case and the fourth case described above.

[0178] It should be noted that when the buffer structure 82 wraps the intersection T between the side surface 81c of the circuit board 81 close to the selected first side surface 1cc and the sixth surface 81b of the circuit board 81, the portion 8b1 (i.e. Figure 17B the portion corresponding to the dashed-dotted rectangular frame in FIG. 8B) of the outer surface 82a of the buffer structure 82 on the side of the fourth surface 8b forms the fourth surface 8b.

[0179] In some embodiments, the material of the buffer structure 82 includes an organic material.

[0180] For example, the material of the buffer structure 82 can be resin, polyimide.

[0181] The organic material described above is not prone to deformation at high temperatures, and the buffer material is prepared by using the organic material described above. When the connecting lead 3 is prepared by the printing process, the buffer structure 82 is not prone to deformation during the high-temperature curing of the initial connecting lead and the high-temperature curing of the initial protective layer, and the conductive paste can stably and slowly climb along the buffer structure 82.

[0182] In some embodiments, as Figure 20As shown, each back electrode 4 includes a first straight portion 41, a diagonal portion 42, and a second straight portion 43. The first straight portion 41 extends perpendicular to the second direction Y, which is the direction of extension of the boundary between the first selected side surface and the second surface 1b. The diagonal portion 42 is connected to the first straight portion 41, and the extension direction of the first straight portion 41 intersects with the extension direction of the diagonal portion 42. The second straight portion 43 is connected to the diagonal portion 42 and extends perpendicular to the second direction Y. The second straight portion 43 is farther away from the selected first side surface 1cc than the first straight portion 41. The third portion 33 of the connecting lead 3 is electrically connected to the first straight portion 41, and the second straight portion 43 is used to connect to the flexible circuit board 9. The first straight portions 41 of the plurality of back electrodes 4 are arranged along the second direction Y, and the second straight portions 43 of the plurality of back electrodes 4 are arranged along the second direction Y. The dimension D10 of the plurality of second straight portions 43 along the second direction Y is smaller than the dimension D9 of the plurality of first straight portions 41 along the second direction Y.

[0183] The dimension D10 of the plurality of second straight portions 43 along the second direction Y is smaller than the dimension D9 of the plurality of first straight portions 41 along the second direction Y. This allows the plurality of oblique portions 42 connecting the plurality of second straight portions 43 and the plurality of first straight portions 41 to extend toward the centerline O of the fourth surface 8b. The region corresponding to the plurality of oblique portions 42 thus forms the fan-out region SS of the back electrode 4. This allows the plurality of second straight portions 43 to converge inward relative to the plurality of first straight portions 41, resulting in a smaller region corresponding to the plurality of second straight portions 43 than to the region corresponding to the plurality of first straight portions 41, facilitating electrical connection to the flexible printed circuit board 9.

[0184] For example, Figure 20 As shown, the minimum dimension D11 of the bridge structure 8 along the second direction Y is the dimension D9 of the plurality of first straight portions 41 along the second direction Y. The maximum dimension D11 of the bridge structure 8 along the second direction Y is (M-30 μm), where M is the dimension of the substrate 1 along the second direction Y.

[0185] For example, Figure 20 As shown, the dimension D12 of the bridge structure 8 along the third direction Z ranges from 3 mm to 50 mm. This dimension range is appropriately selected so that the area of ​​the fourth surface 8 b of the bridge structure 8 is sufficient for the plurality of oblique portions 42 to form the fan-out region SS of the back electrode 4. The dimension D12 of the bridge structure 8 along the third direction Z ranges from 3 mm to 50 mm, for example.

[0186] In some examples, such as Figure 1As shown, the second straight portion 43 is directly electrically connected to the flexible circuit board 9, or the second straight portion 43 is electrically connected to the flexible circuit board 9 through an external lead. The flexible circuit board 9 is, for example, a COF (Chip On Film) flexible circuit board 9.

[0187] In some examples, such as Figure 21 As shown, a fourth interval L4 is formed between the first straight portion 41, which is close to the edge of the selected first side surface 1cc, and the intersection of the selected second side surface 8cc and the fourth surface 8b. The fourth interval L4 ranges from 0 to 1 mm. For example, the fourth interval L4 is 0 mm, 0.5 mm, or 1 mm.

[0188] For example, Figure 21 As shown, the length D13 of the first straight portion 41 along its extending direction is greater than or equal to 60 μm. The length D13 of the first straight portion 41 along its extending direction is, for example, 60 μm, 80 μm, or 90 μm.

[0189] For example, Figure 21 As shown, the dimension D14 of the first straight portion 41 along the second direction Y is greater than 50 μm. The dimension D14 of the first straight portion 41 along the second direction Y is, for example, 55 μm, 60 μm, or 70 μm.

[0190] For example, Figure 21 As shown, the distance D15 between two adjacent first straight portions 41 is greater than or equal to 100 μm.

[0191] This arrangement can prevent short circuits between two adjacent first straight portions 41 and leave enough space for the protective layer 6 to ensure the protective effect of the protective layer 6. The spacing between two adjacent first straight portions 41 is, for example, 100 μm, 120 μm, or 150 μm.

[0192] On the other hand, Figure 22A and Figure 22B As shown, a display device 100 is provided, comprising a display panel 10 and a driving circuit board 20 provided in any of the aforementioned embodiments. The driving circuit board 20 is electrically connected to the display panel 10; for example, the driving circuit board 20 is electrically connected to the back electrode of the display panel 10 via the flexible circuit board 9. The electrical signal provided by the driving circuit board 20 is transmitted to the driving circuit layer of the display panel 10 via the flexible circuit board 9, the back electrode 4, the connecting traces 3, and the front electrode 2 to control the light-emitting device to emit light. The driving circuit board 20 is configured to drive the display panel 10 to display an image.

[0193] The display device 100 can be any device that displays, whether in motion (e.g., video), fixed (e.g., a still image), textual, or graphical. More particularly, it is contemplated that the embodiments can be implemented in or in association with a variety of electronic devices such as, but not limited to, mobile telephones, wireless devices, personal data assistants (PDAs), handheld or portable computers, GPS receivers / navigators, cameras, MP3 players, camcorders, game consoles, wrist watches, clocks, calculators, television monitors, flat panel displays, computer monitors, auto displays (e.g., odometer display, etc.), cockpit controls and / or displays, camera view displays (e.g., display of a rear view camera in a vehicle), electronic photographs, electronic billboards or signs, projections, architectural structures, packaging, and aesthetic structures (e.g., display of images on a piece of jewelry) and the like.

[0194] Exemplarily, the display device 100 can further include a frame and other electronic accessories, etc. Wherein, the display panel 10 can be disposed in the frame, for example.

[0195] In another aspect, a tiled display device 1000 is provided, comprising a plurality of display devices 100 as provided by any of the above embodiments.

[0196] Exemplarily, as shown in Figure 24 and Figure 26 , the plurality of display devices 100 in the tiled display device 1000 are arranged in an array.

[0197] Exemplarily, as shown in Figure 24 and Figure 26 , the display device 100 is rectangular, for example.

[0198] In the display panel 10, the plurality of front electrodes 22 are arranged in parallel and spaced apart along the second direction Y, and correspondingly, the plurality of connecting leads 3 are also arranged in parallel and spaced apart along the second direction Y, and the third direction Z is another direction parallel to the display device 100 and perpendicular to the second direction Y. The display device 100 includes a plurality of sides, and in the following, the side of the display device 100 close to the plurality of front electrodes 22 is referred to as the selected side of the display device 100 for description.

[0199] Exemplarily, as shown in Figure 23 , the display panel 10 includes a display area AA and two binding areas BB located on opposite sides of the display area AA, and the display panel 10 includes two groups of front electrodes 2, each group of front electrodes 2 includes a plurality of front electrodes 2, and the two groups of front electrodes 2 are respectively close to the two binding areas BB.

[0200] Further, as shown in Figure 24 , the plurality of front electrodes 2 include a plurality of front electrodes 2 as shown in Figure 23As shown in the display panel 10, the display device 100 is spliced, and the selected side of each of the two adjacent display devices 100 is arranged along the second direction Y. In this way, in the plurality of display devices 100 arranged in a row along the second direction Y, there is substantially no joint gap between the two adjacent display devices 100 along the second direction Y. In the plurality of display devices 100 arranged in a column along the third direction Z, there is a joint gap between the two adjacent display devices 100. That is, in the plurality of display devices 100 arranged in a row along the second direction Y, the size of the joint gap between the two adjacent display devices 100 is smaller than the size of the joint gap between the two adjacent display devices 100 arranged in a column along the third direction Z.

[0201] However, the size of the binding area BB in the third direction Z is small. Therefore, in actual viewing, the joint gap between the two adjacent display devices 100 is difficult to be found by the naked eye within the viewing distance, so that the display screen of the spliced display device 1000 is relatively complete, and a better display effect can be presented.

[0202] For example, as shown in the display panel 10, Figure 25 The display panel 10 includes a display area AA and a binding area BB located on one side of the display area AA, and a plurality of front electrodes 22 are arranged in the binding area BB.

[0203] Further, as shown in the display panel 10, Figure 26 The display panel 10 includes a display area AA and a binding area BB located on one side of the display area AA, and a plurality of front electrodes 22 are arranged in the binding area BB. Figure 25 As shown in the display panel 10, the display device 100 is spliced, and the selected side of each of the two adjacent display devices 100 is arranged along the second direction Y. In this way, in the plurality of display devices 100 arranged in a row along the second direction Y, there is substantially no joint gap between the two adjacent display devices 100 along the second direction Y. In the plurality of display devices 100 arranged in a column along the third direction Z, there is a joint gap between the two adjacent display devices 100. That is, in the plurality of display devices 100 arranged in a row along the second direction Y, the size of the joint gap between the two adjacent display devices 100 is smaller than the size of the joint gap between the two adjacent display devices 100 arranged in a column along the third direction Z.

[0204] However, the size of the binding area BB in the third direction Z is small. Therefore, in actual viewing, the joint gap between the two adjacent display devices 100 is difficult to be found by the naked eye within the viewing distance, so that the display screen of the spliced display device 1000 is relatively complete, and a better display effect can be presented.

[0205] In another aspect, a preparation method of a display panel 10 is provided. As shown in the display panel 10, Figure 27 The preparation method of the display panel 10 includes:

[0206] R1: providing an initial substrate.

[0207] R2: forming a front side film layer structure on the front side of the initial substrate.

[0208] Exemplarily, the front side film layer structure comprises a drive circuit layer.

[0209] R3: forming a plurality of front side electrodes 2 on the front side of the initial substrate in parallel and spaced apart.

[0210] R4: cutting the initial substrate to form a plurality of substrates 1; each substrate 1 comprises a first surface la and a second surface lb arranged oppositely, and a plurality of first side surfaces lc connecting the first surface la and the second surface lb; the plurality of first side surfaces lc comprises at least one selected first side surface lcc.

[0211] The front side electrodes 2 and the film layer structure such as the drive circuit layer are arranged on the front side of the substrate 1. The front side electrodes 2 are close to the selected first side surface lcc.

[0212] R5: arranging a bridge structure 8 on the second surface lb of the substrate 1; the bridge structure 8 comprises a third surface 8a and a fourth surface 8b arranged oppositely, and a plurality of second side surfaces 8c connecting the third surface 8a and the fourth surface 8b; the third surface 8a is close to the fourth surface 8b with respect to the substrate 1; the plurality of second side surfaces 8c comprises at least one selected second side surface 8cc; each selected second side surface 8cc corresponds to one selected first side surface lcc. The third surface 8a and the fourth surface 8b have a first interval L1. Wherein, a first common edge H is the intersection line of the selected second side surface 8cc and the fourth surface 8b, and a second common edge N is the intersection line of the selected second side surface 8cc and the third surface 8a; the normal projection of the first common edge H on the third surface 8a and the normal projection of the second common edge N on the third surface 8a have a second interval L2; the ratio of the first interval L1 to the second interval L2 is between 0.27 and 1.73. The distance between the second common edge N and the first selected side surface is a third interval L3, and the value of the third interval L3 is between 0.5 mm and 2.0 mm.

[0213] The process of connecting the bridge structure 8 to the fourth surface 8b of the substrate 1 is, for example, high-precision attachment, so that the back side electrodes 4 and the front side electrodes 2 are opposite in the first direction X.

[0214] Before R5, a plurality of back side electrodes 4 are formed on the fourth surface 8b of the bridge structure 8, and the plurality of back side electrodes 4 are close to the selected second side surface 8c. Exemplarily, a plurality of back side electrodes are formed by using a wet etching process.

[0215] R6: forming a plurality of connection leads 3 arranged in parallel and spaced apart; each of the plurality of connection leads 3 comprises a first portion 31 located on the side of the first surface la, a second portion 32 located on the side of the selected first side surface lcc, and a third portion 33 located on the side of the second surface lb; the third portion 33 of each of the connection leads 3 is electrically connected to one of the back electrodes 4; the third portion 33 of the connection lead 3 comprises a portion located on the second surface lb, a portion located on the selected second side surface 8cc, and a portion located on the side of the fourth surface 8b.

[0216] Exemplarily, the process of forming the plurality of connection leads 3 is a printing process. The printing process is, for example, screen printing, pad printing, transfer printing, and 3D printing.

[0217] In some embodiments, the method of manufacturing the display panel 10 further comprises, after step R6:

[0218] R7: forming a protective layer 6 on the side of the connection lead 3 away from the selected second side surface 8cc.

[0219] R8: forming a light-blocking layer 7 on the side of the protective layer 6 away from the selected second side surface 8cc, and on the side of the first surface la of the substrate 1.

[0220] In other embodiments, in the case where the bridge structure 8 comprises a circuit board 81 and a buffer structure 82, step R4 comprises:

[0221] R4.1: attaching the circuit board 81 to the second surface lb of the substrate 1.

[0222] The process of connecting the circuit board 81 to the fourth surface 8b of the substrate 1 is, for example, high-precision attachment, so that the back electrode 4 and the front electrode 2 are directly opposite in the first direction X.

[0223] R4.2: forming the buffer structure 82 on the side surface of the circuit board 81 close to the selected first side surface lcc.

[0224] The process of forming the buffer structure 82 is, for example, screen printing, pad printing, transfer printing, and 3D printing.

[0225] The above-mentioned manufacturing process, for example, the printing process, is described only as an example and is not limited to the actual production process.

[0226] The above-mentioned, only for the specific embodiments of the present disclosure, but the scope of protection of the present disclosure is not limited to this, any skilled in the art of the technical personnel in the technical range disclosed by the present disclosure, think of changes or replacement, should be covered in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A display panel, comprising: A substrate comprising a first surface and a second surface disposed opposite to each other, and a plurality of first side surfaces connecting the first surface and the second surface; the plurality of first side surfaces including at least one selected first side surface; a bridge structure disposed on the second surface; the bridge structure comprising a third surface and a fourth surface disposed opposite to each other, and a plurality of second side surfaces connecting the third surface and the fourth surface; the third surface being closer to the substrate than the fourth surface; the plurality of second side surfaces including at least one selected second side surface; each selected second side surface corresponding to a selected first side surface; A plurality of back electrodes are arranged in parallel and at intervals on the fourth surface; a plurality of connecting leads, the plurality of connecting leads being arranged in parallel and spaced apart; each connecting lead comprising a first portion located on one side of the first surface, a second portion located on one side of the selected first side surface, and a third portion located on one side of the second surface; the third portion of each connecting lead being electrically connected to a back electrode; the third portion of the connecting lead comprising a portion located on the second surface, a portion located on the selected second side surface, and a portion located on one side of the fourth surface; the third surface and the fourth surface being spaced apart by a first distance; The first common edge is the intersection line of the selected second side surface and the fourth surface, the second common edge is the intersection line of the selected second side surface and the third surface, the orthographic projection of the first common edge on the third surface and the orthographic projection of the second common edge on the third surface have a second interval, and the ratio of the first interval to the second interval is between 0.27 and 1.73; The distance between the second common edge and the selected first side surface is a third interval, and the value range of the third interval is 0.5 mm to 2.0 mm.

2. The display panel according to claim 1, wherein The portion of the connecting lead located in the area corresponding to the fourth surface has a first thickness, the portion of the connecting lead in the area corresponding to the second surface has a second thickness, and the connecting lead has a third thickness at a position corresponding to the selected second side surface; The first thickness is greater than or equal to the second thickness, and the difference between the first thickness and the second thickness is 0-1 μm; the third thickness is greater than the first thickness or the second thickness, and the difference between the third thickness and the first thickness or the second thickness is 1 μm-3 μm.

3. The display panel according to claim 1, wherein: A cross section of the selected second side surface perpendicular to the first common edge or the second common edge is a straight line segment, a curved line segment, or a broken line segment, and the curved line segment bends away from the second surface.

4. The display panel according to claim 1, wherein: The selected second side surface is a plane, and the angle between the selected second side surface and the third surface is in the range of 10° to 80°.

5. The display panel according to claim 1, wherein: The selected second side surface includes a plurality of sub-surfaces connected in sequence; Of the two adjacent sub-surfaces, the sub-surface farther from the selected first side surface is farther from the second surface relative to the other sub-surface. The display panel according to claim 5 , wherein: The plurality of sub-surfaces are planes, and the selected second side surface is stepped; The selected second side surface includes at least two first sub-surfaces and at least one second sub-surface that are alternately arranged, and the sub-surface closest to the fourth surface and the sub-surface closest to the second surface among the multiple sub-surfaces are both first sub-surfaces; The at least two first sub-surfaces are parallel to the selected first side surface; and / or The second sub-surface is parallel to the second surface.

7. The display panel according to claim 6, wherein: The orthographic projections of the at least two first sub-surfaces on the first reference plane have a first size in the first direction; the first reference plane is parallel to the selected first side surface; The first direction is the thickness direction of the substrate; and / or The orthographic projection of the at least one second sub-surface on the second reference plane has a second dimension in the third direction; the second reference plane is parallel to the second surface; and the third direction is perpendicular to the selected first side surface.

8. The display panel according to any one of claims 1 to 7, wherein: The bridging structure comprises: A circuit board, comprising a fifth surface and a sixth surface arranged opposite to each other, and a plurality of third side surfaces connecting the fifth surface and the sixth surface, wherein the plurality of third side surfaces include at least one selected third side surface; the selected third side surface serves as the selected second side surface; and the plurality of back electrodes are arranged in parallel and spaced apart on the sixth surface.

9. The display panel according to claim 8, wherein: The circuit board comprises an adhesive layer and a carrier body that are stacked, wherein the adhesive layer is closer to the substrate relative to the carrier body; The selected third side surface of the circuit board is stepped, and the distance between the end of the carrier body close to the selected first side surface and the selected first side surface is smaller than the distance between the end of the adhesive layer close to the selected first side surface and the selected first side surface.

10. The display panel according to claim 9, wherein: The ratio of the thickness of the adhesive layer to the thickness of the carrier body is in a range of 1.4 to 1.

6.

11. The display panel according to any one of claims 1 to 7, wherein: The bridging structure comprises: A circuit board; the circuit board includes a fifth surface and a sixth surface arranged opposite to each other, and a plurality of third side surfaces connecting the fifth surface and the sixth surface; the plurality of back electrodes are arranged in parallel and spaced apart on the sixth surface; The buffer structure is located on a side of the circuit board close to the selected first side surface; the outer surface of the buffer structure serves as at least a part of the selected second side surface, and the outer surface of the buffer structure is the surface of the buffer structure away from the circuit board and the second surface.

12. The display panel according to claim 11, wherein: The buffer structure includes a plurality of first sub-buffer structures, and at least a portion of each connecting lead is correspondingly arranged on one of the plurality of first sub-buffer structures.

13. The display panel according to claim 11, wherein: The multiple connecting leads include multiple groups of connecting leads, each group of connecting leads includes at least two connecting leads; the buffer structure includes multiple second sub-buffer structures, and at least a portion of each group of connecting leads is correspondingly arranged on a second sub-buffer structure among the multiple second sub-buffer structures.

14. The display panel according to claim 11, wherein: The buffer structure extends along a second direction, which is the extension direction of the boundary line between the selected first side surface and the second surface, and the length of the buffer structure is greater than the distance between the outer edges of the two outermost connecting leads in the orthographic projection of the multiple connecting leads on the second surface, and the outer edges of the two connecting leads are the sides of the two connecting leads that are away from each other.

15. The display panel according to claim 11, wherein The cross-section of the surface of the buffer structure away from the circuit board and the second surface, which is perpendicular to the first common edge or the second common edge, is a straight line segment, a curve segment or a broken line segment, and the curve segment bends away from the second surface; or, the surface of the buffer structure away from the circuit board and the second surface includes multiple sub-surfaces connected in sequence.

16. The display panel according to claim 11, wherein The buffer structure further wraps a boundary portion between a side surface of the circuit board close to the selected first side surface and the sixth surface of the circuit board.

17. The display panel according to claim 11, wherein: The material of the buffer structure includes organic material.

18. The display panel according to any one of claims 1 to 7, wherein: The dimension of the end portion of the connecting lead located on the second surface and close to the bridging structure in the second direction is greater than the dimension of the other portions of the connecting lead in the second direction; the second direction is the extension direction of the boundary line between the selected first side surface and the second surface.

19. The display panel according to any one of claims 1 to 7, wherein: Each of the back electrodes comprises: a first straight portion extending in a direction perpendicular to a second direction; the second direction being an extending direction of a boundary line between the selected first side surface and the second surface; an oblique portion connected to the first straight portion, wherein an extending direction of the first straight portion intersects an extending direction of the oblique portion; a second straight portion connected to the oblique portion and extending in a direction perpendicular to the second direction; the second straight portion is farther away from the selected first side surface than the first straight portion; The third portion of the connecting lead is electrically connected to the first straight portion, and the second straight portion is used to connect to the flexible circuit board; The first straight portions of the plurality of back electrodes are arranged along the second direction, the second straight portions of the plurality of back electrodes are arranged along the second direction, and the size of the plurality of second straight portions along the second direction is smaller than the size of the plurality of first straight portions along the second direction.

20. A display device comprising: The display panel according to any one of claims 1 to 19; 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.

21. A spliced ​​display device comprising a plurality of display devices according to claim 20.

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