Light-emitting substrate, manufacturing method therefor, display panel, and display device

Abstract

A light-emitting substrate, a manufacturing method therefor, a display panel, and a display device. The light-emitting substrate comprises a substrate and a plurality of connecting traces; the substrate has a first surface and a second surface which are opposite to each other, and a side surface connecting the first surface and the second surface; the plurality of connecting traces are arranged in parallel and at intervals; the connecting traces extend from the first surface to the second surface via the side surface; each connecting trace comprises a first trace section provided on the first surface, a second trace section provided on the side surface, and a third trace section provided on the second surface, wherein the second trace section comprises a first end close to the first trace section, and a second end close to the third trace section; the second trace section comprises a first end close to the first trace section, and a second end close to the third trace section; the trace width of the first end of the second trace section is smaller than the trace width of the first trace section; and the trace width of the second end of the second trace section is smaller than the trace width of the third trace section.

Description

Light-emitting substrate and its preparation method, display panel, display device Technical Field

[0001] This disclosure relates to the field of display technology, and in particular to a light-emitting substrate and its preparation method, a display panel, and a display device. Background Technology

[0002] Micro LED (Micro Light Emitting Diode) and Mini LED (Mini Light Emitting Diode Display) are smaller than traditional LEDs, meaning they are smaller in size. They are widely used in display devices, forming Micro LED / Mini LED display devices, which have a higher display effect. Summary of the Invention

[0003] On one hand, a light-emitting substrate is provided. The light-emitting substrate includes a substrate and a plurality of connection traces. The substrate includes a first surface and a second surface disposed opposite to each other, and a side surface connecting the first surface and the second surface; the plurality of connection traces are arranged side by side and spaced apart; the connection traces extend from the first surface through the side surface to the second surface, and each connection trace includes a first segment of trace disposed on the first surface, a second segment of trace disposed on the side surface, and a third segment of trace disposed on the second surface; wherein the second segment of trace includes a first end near the first segment of trace and a second end near the third segment of trace; the linewidth of the first end of the second segment of trace is smaller than the linewidth of the first segment of trace, and the linewidth of the second end of the second segment of trace is smaller than the linewidth of the third segment of trace.

[0004] In some embodiments, the ratio of the line width of the first end of the second trace to the line width of the first trace ranges from 0.75 to 0.85.

[0005] In some embodiments, the ratio of the line width of the second end of the second segment to the line width of the third segment ranges from 0.75 to 0.85.

[0006] In some embodiments, the ratio of the line width of the second end of the second segment to the line width of the third segment is in the range of 1 / 3 to 1 / 2.

[0007] In some embodiments, the line width at the first end of the second trace is greater than the line width at the second end.

[0008] In some embodiments, the line width at the first end and the line width at the second end of the second trace are equal.

[0009] In some embodiments, the second trace includes a first part and a second part connected together, the end of the first part away from the second part is the first end of the second trace, and the end of the second part away from the first part is the second end of the second trace; from the first end of the second trace to the end where the first part and the second part are connected, the line width of the first part gradually increases; from the second end of the second trace to the end where the second part and the first part are connected, the line width of the second part gradually increases.

[0010] In some embodiments, the first part includes a first side and a second side opposite to each other in a first direction, and the second part includes a third side and a fourth side opposite to each other in the first direction; the first direction is perpendicular to the direction from the first end to the second end of the second segment of the trace; one end of the first side is connected to one end of the third side, and one end of the second side is connected to one end of the fourth side.

[0011] In some embodiments, the end of the first part near the second part partially overlaps with the end of the second part near the first part; the portion of the first part near the second part protrudes on the first side of the second trace; and the portion of the second part near the first part protrudes on the second side of the second trace.

[0012] In some embodiments, the position where the first part and the second part are connected is located at the midpoint of the second segment of the trace in a second direction; the second direction is the direction from the first end to the second end of the second segment of the trace.

[0013] In some embodiments, the ratio of the line width of the first end and / or the second end of the second segment to the average line width of the second segment ranges from 0.75 to 0.85.

[0014] In some embodiments, the substrate further includes a first transition surface connected between the first surface and the side surface, and a second transition surface connected between the second surface and the side surface; the connection trace further includes a fourth trace disposed on the first transition surface and a fifth trace disposed on the second transition surface, the fourth trace connecting the first trace and the second trace, and the fifth trace connecting the second trace and the third trace; the linewidth of the end of the fourth trace connected to the first trace is greater than the linewidth of the end of the fourth trace connected to the second trace; and / or, the linewidth of the end of the fifth trace connected to the third trace is greater than the linewidth of the end of the fifth trace connected to the second trace.

[0015] In some embodiments, the line width of the fourth trace gradually decreases from the end where the fourth trace connects to the first trace to the end where the fourth trace connects to the second trace; and / or, the line width of the fifth trace gradually decreases from the end where the fifth trace connects to the third trace to the end where the fifth trace connects to the second trace.

[0016] In some embodiments, the line width of the fourth trace satisfies at least one of the following: the line width of the end of the fourth trace connected to the first trace is equal to the line width of the first trace; the line width of the end of the fourth trace connected to the second trace is equal to the line width of the first end of the second trace; the line width of the end of the fifth trace connected to the third trace is equal to the line width of the third trace; and the line width of the end of the fifth trace connected to the second trace is equal to the line width of the second end of the second trace.

[0017] In some embodiments, the average line width of the fourth trace is less than the maximum line width of the second trace; and / or, the average line width of the fifth trace is less than the maximum line width of the second trace.

[0018] In some embodiments, the surface of the connecting trace is arc-shaped in its cross-section; the cross-section is the section of the connecting trace along its extension direction perpendicular to itself.

[0019] In some embodiments, the light-emitting substrate further includes a plurality of front electrodes and a plurality of light-emitting devices. The plurality of front electrodes are arranged side by side and spaced apart on the first surface. The first segment of each of the plurality of connection traces is electrically connected to one of the plurality of front electrodes. The plurality of light-emitting devices are disposed on the first surface and are located away from the plurality of connection traces relative to the plurality of front electrodes. The plurality of light-emitting devices are electrically connected to the plurality of front electrodes.

[0020] In some embodiments, the light-emitting substrate further includes a bridging structure and a back electrode. The bridging structure is disposed on the second surface and includes 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 is close to the substrate relative to the fourth surface. The plurality of back electrodes are disposed side-by-side and spaced apart on the fourth surface of the bridging structure. A third trace is electrically connected to one of the plurality of back electrodes. The third trace extends from the second surface through the second side surface and the fourth surface to the back electrode, and the portion of the third trace disposed on the back electrode is a third part.

[0021] Wherein, the ratio of the dimension of the third part in the third direction to the dimension of the back electrode in the third direction is 1 / 3 to 1 / 2, and the third direction is the extension direction of the back electrode and the third segment of the trace.

[0022] In some embodiments, the dimensions of the third part in the first direction are the same as the dimensions of the bridging structure and the back electrode in the first direction.

[0023] On the other hand, a display panel is provided, the display panel comprising: a light-emitting substrate as described in any of the above embodiments.

[0024] In another aspect, a display device is provided. The display device includes a display panel as described in the above embodiments and a driving circuit board, wherein the driving circuit board is electrically connected to the display panel.

[0025] In another aspect, a splicing display device is provided, the splicing display device comprising: a plurality of display panels spliced ​​together, the display panels being the display panels described in the above embodiments; or, a plurality of display devices spliced ​​together, the display devices being the display devices described in the above embodiments.

[0026] In another aspect, a driving method for a light-emitting substrate is provided. The driving method includes: forming a photoresist layer on a first surface, a target side surface, and a second surface of the substrate; the substrate includes a first end and a second end opposite to each other, the first end being the end where the target side surface is located; performing two exposures on the photoresist layer followed by development to expose areas where interconnection traces are to be formed; depositing interconnection trace material on the first surface, the target side surface, and the second surface of the substrate; and peeling off the photoresist layer to form multiple interconnection traces; the interconnection traces include a first trace disposed on the first surface, a second trace disposed on the side surface, and a third trace disposed on the second surface; the linewidth of the first end of the second trace is smaller than the linewidth of the first trace, and the linewidth of the second end of the second trace is smaller than the linewidth of the third trace.

[0027] In some embodiments, the step of performing two exposures on the photoresist layer includes: tilting the substrate relative to a stage, with the first surface of the substrate being farther from the stage than the second surface, and the first end of the substrate being higher than the second end of the substrate; exposing a first target area of ​​the photoresist layer on the first surface and the target side surface of the substrate; flipping the substrate so that the second surface of the substrate is farther from the stage than the first surface, while maintaining the substrate tilted relative to the stage, with the first end of the substrate being higher than the second end of the substrate; and exposing a second target area of ​​the photoresist layer on the second surface and the target side surface of the substrate.

[0028] In some embodiments, the photoresist layer is made of negative photoresist; the first target region and the second target region include the region between the interconnect traces to be formed.

[0029] In some embodiments, the opening of the mask used for the exposure includes a first portion and a second portion arranged and connected along a first preset direction, wherein the size of the first portion along a second preset direction is larger than the size of the second portion along the second preset direction; the second preset direction is perpendicular to the first preset direction; during the exposure process, the first portion of the opening of the mask corresponds to the photoresist layer on the target side surface. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in this disclosure, the accompanying drawings used in some embodiments of this disclosure will be briefly described below. Obviously, the drawings described below are only drawings of some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams and are not intended to limit the actual size of the product, the actual flow of the method, the actual timing of the signals, etc. involved in the embodiments of this disclosure.

[0031] Figure 1 is a cross-sectional structural diagram of a display panel according to some embodiments of the present disclosure;

[0032] Figure 2 is a plan view of a display panel according to some embodiments of the present disclosure;

[0033] Figure 3 is a structural diagram of a connection wiring according to some embodiments of the present disclosure;

[0034] Figure 4 is a structural diagram of another connection wiring according to some embodiments of the present disclosure;

[0035] Figure 5 is a structural diagram of the second segment of the connecting trace according to some embodiments of the present disclosure;

[0036] Figure 6 is a perspective structural diagram of a display panel according to some embodiments of the present disclosure;

[0037] Figure 7 is a cross-sectional structural diagram of the connecting traces according to some embodiments of the present disclosure;

[0038] Figure 8 is a cross-sectional structural diagram of the connecting traces according to some embodiments of the related art;

[0039] Figure 9 is another cross-sectional structural diagram of a display panel according to some embodiments of the present disclosure;

[0040] Figure 10 is a connection structure diagram of the third segment of the connection trace and the back electrode according to some embodiments of the present disclosure;

[0041] Figure 11A is a structural diagram of a fabrication process for a connection trace according to some embodiments of the present disclosure;

[0042] Figure 11B is a structural diagram of another connection wiring fabrication process according to some embodiments of the present disclosure;

[0043] Figure 11C is a structural diagram of the fabrication process of another connection wiring according to some embodiments of the present disclosure;

[0044] Figure 11D is a structural diagram of another fabrication process for a connection trace according to some embodiments of the present disclosure;

[0045] Figure 12 is another structural diagram of the connection wiring according to some embodiments of the present disclosure;

[0046] Figure 13A is a structural diagram of a fabrication process for a connection trace according to some embodiments of the present disclosure;

[0047] Figure 13B is a structural diagram of another connection wiring fabrication process according to some embodiments of the present disclosure;

[0048] Figure 13C is a structural diagram of the fabrication process of another connection trace according to some embodiments of the present disclosure;

[0049] Figure 13D is a structural diagram of another fabrication process for a connection trace according to some embodiments of the present disclosure;

[0050] Figure 14A is another structural diagram of the connection wiring according to some embodiments of the present disclosure;

[0051] Figure 14B is another structural diagram of the connection wiring according to some embodiments of the present disclosure;

[0052] Figure 15 is a structural diagram of a mask according to some embodiments of the present disclosure;

[0053] Figure 16 is a plan view of a display device according to some embodiments of the present disclosure;

[0054] Figure 17 is a cross-sectional structural diagram of a display device according to some embodiments of the present disclosure;

[0055] Figure 18 is a structural diagram of a splicing display device according to some embodiments of the present disclosure;

[0056] Figure 19 is a structural diagram of a display panel according to some embodiments of the present disclosure;

[0057] Figure 20 is a structural diagram of a splicing display device according to some embodiments of the present disclosure. Detailed Implementation

[0058] The technical solutions in some embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this disclosure are within the scope of protection of this disclosure.

[0059] Unless the context otherwise requires, throughout the specification and claims, the term "comprise" and its other forms, such as the third-person singular "comprises" and the present participle "comprising," are interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific example," or "some examples," etc., are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0060] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0061] In describing some embodiments, the terms "coupled" and "connected," and their derivative expressions, may be used. The term "connected" should be interpreted broadly; for example, a "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection via an intermediate medium. The term "coupled," for example, indicates that two or more components have direct physical or electrical contact. The term "coupled" or "communicatively coupled" may also refer to two or more components that do not have direct contact with each other but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the content of this document.

[0062] "At least one of A, B and C" has the same meaning as "at least one of A, B or C", and includes the following combinations of A, B and C: only A, only B, only C, combinations of A and B, combinations of A and C, combinations of B and C, and combinations of A, B and C.

[0063] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0064] As used herein, depending on the context, the term "if" may optionally be interpreted as meaning "when," "at," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrases "if it is determined..." or "if [the stated condition or event] is optionally interpreted as meaning "in response to determination..." or "in response to detection of [the stated condition or event]."

[0065] The use of “applies to” or “configured to” in this article implies an open and inclusive language that does not preclude applicability to or configuration to devices that perform additional tasks or steps.

[0066] In addition, the use of “based on” implies openness and inclusivity, because processes, steps, calculations or other actions “based on” one or more of the stated conditions or values ​​may in practice be based on additional conditions or values ​​beyond those stated.

[0067] As used herein, “about,” “approximately,” or “approximately” includes the stated value and the average value within an acceptable range of deviation from the given value, wherein the acceptable range of deviation is determined by a person skilled in the art taking into account the measurement under discussion and the error associated with the measurement of the given quantity (i.e., the limitations of the measurement system).

[0068] As used herein, “parallel,” “perpendicular,” and “equal” include the described situation and situations that are similar to the described situation, within an acceptable range of deviation, which is determined by those skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, “parallel” includes absolute parallelism and approximate parallelism, where an acceptable range of deviation for approximate parallelism may be, for example, within 5°; “perpendicular” includes absolute perpendicularity and approximate perpendicularity, where an acceptable range of deviation for approximate perpendicularity may also be, for example, within 5°; “equal” includes absolute equality and approximate equality, where an acceptable range of deviation for approximate equality may be, for example, a difference between the two equals being less than or equal to 5% of either one.

[0069] It should be understood that when a layer or element is referred to as being on another layer or substrate, it can mean that the layer or element is directly on the other layer or substrate, or that there is an intermediate layer between the layer or element and the other layer or substrate.

[0070] This document describes exemplary embodiments with reference to cross-sectional views and / or plan views, which are idealized exemplary drawings. In the drawings, the thickness of layers and the area of ​​regions are enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as being limited to the shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing processes. For example, etched areas shown as rectangular would typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of the areas of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0071] It should be noted that, for example, 33-3 in the accompanying drawings of this disclosure indicates that component 33 belongs to component 3, and 1b-1 indicates that the second surface 1b belongs to substrate 1. Other similar reference numerals in the accompanying drawings also follow the above description. For example, 1c / 1cc in the accompanying drawings of this disclosure indicates that plane 1c and plane 1cc can both be represented with reference to this plane. Other similar reference numerals in the accompanying drawings also follow the above description.

[0072] To improve product reliability and reduce transportation and maintenance costs, large-size display devices can be assembled by splicing together multiple small-size display devices.

[0073] To avoid a fragmented display caused by splicing, it is necessary to reduce the bezel size of individual small display devices and decrease the seam width. Small display devices include display panels. For example, side traces can be used to connect the traces on the display side of the display panel to a circuit board (e.g., a flexible circuit board) on the non-display side of the display panel. This allows for smaller spacing between adjacent small display devices when multiple small display devices are spliced ​​together to form a larger display device, thus reducing the seam width and improving display quality.

[0074] The following describes the light-emitting substrate, its preparation method, the display panel, and the display device provided in this disclosure.

[0075] In this disclosure, the reference numerals A / B to C appearing in the accompanying drawings indicate that A and B can both refer to the structure indicated by the reference numeral, and that A / B both belong to C. Similar reference numerals appearing in the accompanying drawings also follow the above description.

[0076] In some embodiments, as shown in FIG1, the light-emitting substrate 10 includes a plurality of front electrodes 2, a plurality of connection traces 3, and a plurality of back electrodes 4. The substrate 1 includes a first surface 1a and a second surface 1b disposed opposite to each other, and a side surface 1c connecting the first surface 1a and the second surface 1b. The plurality of front electrodes 2 are arranged side-by-side and spaced apart on the first surface 1a, and the plurality of connection traces 3 are arranged side-by-side and spaced apart. The connection traces 3 extend from the first surface 1a through the side surface 1c to the second surface 1b, and each connection trace 3 includes a first trace 31 disposed on the first surface 1a, a second trace 32 disposed on the side surface 1c, and a third trace 33 disposed on the second surface 1b.

[0077] For example, at least one of the plurality of side surfaces 1c of the substrate 1 is a selected side surface 1cc. Each selected side surface 1cc is provided with a plurality of connection traces 3.

[0078] For example, the first surface 1a of the substrate 1 is the light-emitting surface of the light-emitting substrate 10. A display area AA and a bonding area CC are disposed on one side of the first surface 1a of the substrate 1. A driving circuit layer (not shown in the figure) and a light-emitting device layer 5 are disposed in the display area AA. The light-emitting device layer 5 is located away from the selected side surface 1cc relative to the front electrode 2. The light-emitting device layer 5 includes multiple light-emitting devices 51, which are disposed on the first surface 1a and are located away from the multiple front electrodes 2 and multiple connection lines 3. The light-emitting device layer 5 includes light-emitting devices 51 of at least three colors. The multiple color light-emitting devices 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, second color, and third color are three primary colors (e.g., red, green, and blue). For example, the light-emitting device 51 is a Micro LED (Micro Light Emitting Diode) and a Mini LED (Mini Light Emitting Diode Display).

[0079] As shown in Figures 1 and 2, one side of the first surface 1a of the substrate 1 is the light-emitting surface of the light-emitting substrate 10. Multiple front electrodes 2 extend along a third direction Z and are arranged side-by-side at intervals along a first direction X, which is parallel to the boundary line between the selected side surface 1cc and the first surface 1a. The multiple front electrodes 2 are electrically connected to at least a portion of a driving circuit layer (not shown in the figures). Exemplarily, the driving circuit layer includes multiple signal lines, and the multiple front electrodes 2 are electrically connected to multiple light-emitting devices 51 through these signal lines. The signal lines are configured to transmit signals to the multiple light-emitting devices 51, driving the multiple light-emitting devices 2 to emit light. The first segment 31 of multiple connection traces 3 is located on one side of the first surface 1a of the substrate 1 and is electrically connected to each of the multiple front electrodes 2 in a one-to-one correspondence. The extension direction of the first segment 31 of the multiple connection traces 3 is, for example, a direction perpendicular to the selected side surface 1cc of the substrate 1, i.e., the third direction Z shown in Figure 1.

[0080] For example, continuing to refer to FIG1, the second surface 1b of the substrate 1 is the backlight surface of the light-emitting substrate 10. The third segment 33 of the multiple connecting lines 3 is located on the second surface 1b of the substrate 1, that is, the third segment 33 of the connecting lines 3 is the portion of the connecting lines 3 located on the back side of the light-emitting substrate 10. The extension direction of the third segment 33 of the multiple connecting lines 3 is, for example, the third direction Z. Multiple back electrodes 4 are disposed on the second surface 1b of the substrate and arranged side by side at intervals along the first direction X. The multiple back electrodes 4 can serve as bonding electrodes for connecting flexible circuit boards, and the third segment 33 of the multiple connecting lines 3 is electrically connected to the multiple back electrodes 4 in a one-to-one correspondence.

[0081] In some examples, as shown in Figure 1, the display panel 100 includes a protective layer 6 and a light-blocking layer 7. The protective layer 6 covers the side of the connecting traces 3 and is configured to provide all-around protection to the connecting traces 3, preventing water and oxygen corrosion from contacting air and / or moisture, which could affect the conductivity of the connecting traces 3. The light-blocking layer 7 covers the side of the protective layer 6 away from the connecting traces 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; on the other hand, it can prevent light emitted from the light-emitting device layer 5 from leaking at the seams of the splicing display device.

[0082] In some embodiments of the related technology, the process for preparing multiple interconnecting lines 3 includes: attaching photosensitive films to portions of the first surface 1a, the second surface 1b, and the selected side surface 1cc of the substrate 1; performing three exposures on the photoresist located on the first surface 1a, the second surface 1b, and the selected side surface 1cc, followed by development; etching away the areas corresponding to the interconnecting lines; then performing a stereolithography coating process to coat the portions of the first surface 1a, the second surface 1b, and the selected side surface 1cc of the substrate 1; and finally peeling off the remaining unetched photosensitive film to form multiple interconnecting lines 3.

[0083] In the aforementioned process, the first surface 1a, the second surface 1b, and the selected side surface 1cc are exposed separately. This may result in secondary exposure at the connection points between the selected side surface 1cc and the first surface 1a, and between the selected side surface 1cc and the second surface 1b. Consequently, the photosensitive film in these areas has a higher exposure level, and the area etched to form the connection traces becomes larger. This means that the gaps between adjacent connection traces will decrease, or even disappear. In this case, the connection traces formed by the stereo sputtering deposition process are prone to contact and short circuits at the connection points between the selected side surface 1cc and the first surface 1a, and between the selected side surface 1cc and the second surface 1b. Furthermore, due to the use of three-stage splicing exposure, the alignment errors at the splicing positions of the formed connection traces can be significant, and may even lead to breaks in the splicing of the connection traces.

[0084] Based on this, this application employs a two-exposure process in the fabrication of the interconnect traces. This not only reduces production costs but also further reduces the alignment error of the interconnect traces by reducing the number of times they are spliced.

[0085] In some embodiments, as shown in FIG3, the second trace 32 includes a first end 32a near the first trace 31 and a second end 32b near the third trace 33; the line width L21 of the first end 32a of the second trace 32 is smaller than the line width L1 of the first trace 31, and the line width L22 of the second end 32b of the second trace 32 is smaller than the line width L3 of the third trace 33.

[0086] For example, as shown in FIG3, according to the description in the foregoing section, the photosensitive film has a higher degree of exposure at the positions of the first end 32a and the second end 32b of the second segment of the trace 32. After exposure and development, the probability of the connecting trace 3 formed by the stereolithography coating process short-circuiting at the positions of the first end 32a and the second end 32b of the second segment of the trace 32 is also greater. Therefore, by setting the above-mentioned line width relationship, it is possible to avoid the situation where the connecting trace 3 short-circuits at the positions of the first end 32a and the second end 32b of the second segment of the trace 32.

[0087] In some embodiments, referring to FIG3, the ratio of the line width L21 of the first end 32a of the second trace 32 to the line width L1 of the first trace 31 is in the range of 0.75 to 0.85.

[0088] For example, referring to Figure 3, the ratio of the line width L21 of the first end 32a of the second trace 32 to the line width L1 of the first trace can be 0.75, 0.8 or 0.85, etc., and no specific limitation is made here.

[0089] It should be noted that, as described above, the exposure level at the first end 32a of the second trace 32 is relatively high. After exposure and development at this location, the probability of a short circuit occurring at the first end 32a of the second trace 32 after the stereolithography coating process is also higher. Therefore, by setting the above-mentioned line width ratio, it is possible to avoid the short circuit of the connecting trace 3 at the first end 32a of the second trace 32, while ensuring the conductivity of the second trace 32.

[0090] In some embodiments, referring to Figure 3, the ratio of the line width L22 of the second end 32b of the second trace 32 to the line width L3 of the third trace 33 is in the range of 0.75 to 0.85.

[0091] For example, referring to Figure 3, the ratio of the line width L22 of the second end 32b of the second trace 32 to the line width L3 of the third trace 33 can be 0.75, 0.8, or 0.85, etc., and is not specifically limited here. For example, as shown in Figure 3, when the line width L1 of the first trace 31 is equal to the line width L3 of the third trace 33, the line width L21 of the first end 32a of the second trace 32 and the line width L22 of the second end 32b of the second trace 32 can also be equal.

[0092] It should be noted that, as described above, the exposure level at the second end 32b of the second segment of the trace 32 is relatively high. After exposure and development at this location, the probability of a short circuit occurring at the second end 32b of the second segment of the trace 32 after the stereolithography coating process is also greater. Therefore, by setting the above-mentioned line width ratio, it is possible to avoid the short circuit of the connecting trace 3 at the second end 32b of the second segment of the trace 32, while ensuring the conductivity of the second segment of the trace 32.

[0093] In some embodiments, as shown in FIG4, the ratio of the line width L22 of the second end 32b of the second segment trace 32 to the line width of the third segment trace L3 is in the range of 1 / 3 to 1 / 2.

[0094] For example, referring to Figure 4, the ratio of the line width L22 of the first end 32a of the second trace 32 to the line width L3 of the third trace 33 can be 1 / 3, 2 / 5, or 1 / 2, etc., without specific limitation. For example, referring to Figure 4, when the line width L1 of the first trace 31 is equal to the line width L3 of the third trace 33, the line width L21 of the first end 32a of the second trace 32 can be greater than the line width L22 of the second end 32b of the second trace 32.

[0095] It is understandable that, referring to the description above, the above line width ratio setting can also avoid the short circuit of the connecting trace 3 at the second end 32b of the second segment trace 32, while ensuring the conductivity of the second segment trace 32. The line width L21 of the first end 32a of the second segment trace 32 and the line width L22 of the second end 32b of the second segment trace 32 can be different.

[0096] In some embodiments, as shown in FIG4, the line width L21 of the first end 32a of the second trace 32 is greater than the line width L22 of the second end 32b.

[0097] For example, the line width L21 of the first end 32a of the second segment 32 and the line width L22 of the second end 32b of the second segment 32 can be different. The line width L21 of the first end 32a of the second segment 32 and the line width L22 of the second end 32b of the second segment 32 only need to ensure the conductivity of the second segment 32 while avoiding short circuit at the position of the second end 32b of the second segment 32. This will not be elaborated further here.

[0098] In some embodiments, as shown in FIG3, the line width L21 of the first end 32a of the second trace 32 and the line width L22 of the second end 32b are equal.

[0099] For example, the line width L21 of the first end 32a of the second segment 32 and the line width L22 of the second end 32b of the second segment 32 can be equal. They only need to satisfy the requirement that while ensuring the conductivity of the second segment 32, the connection trace 3 can also avoid short circuit at the position of the second end 32b of the second segment 32. This will not be elaborated here.

[0100] In some embodiments, referring to Figures 3 and 4, the second trace 32 includes a first part 321 and a second part 322 connected together. The end of the first part 321 away from the second part 322 is the first end 32a of the second trace 32, and the end of the second part 322 away from the first part 321 is the second end 32b of the second trace 32. From the first end 32a of the second trace 32 to the end where the first part 321 and the second part 322 are connected, the line width of the first part 321 gradually increases. From the second end 32b of the second trace 32 to the end where the second part 322 and the first part 321 are connected, the line width of the second part 322 gradually increases.

[0101] For example, the end where the first part 321 connects to the second part 322 is referred to as the third end 32c, and the end where the second part 322 connects to the first part 321 is referred to as the fourth end 32d. As shown in Figure 3, the first part 321 and the second part 322 are positioned opposite each other. The linewidth L23 of the third end 32c is equal to the linewidth L24 of the fourth end 32d, and both the linewidths L23 and L24 are greater than the linewidth L21 of the first end 32a of the second segment trace 32. Similarly, the linewidths L23 and L24 of the third end 32c and the fourth end 32d are also greater than the linewidth L22 of the second end 32b of the second segment trace 32. The effect achieved by this linewidth of the second segment trace 32 is similar to the effect of the linewidth setting of the second segment trace 32 described above, and will not be elaborated upon here.

[0102] For example, referring to Figure 4, the first part 321 and the second part 322 are arranged opposite to each other. The line width L23 of the third end 32c is equal to the line width L24 of the fourth end 32d. The line width L23 of the third end 32c and the line width L24 of the fourth end 32d are greater than the line width L21 of the first end 32a of the second segment trace 32. The line width L23 of the third end 32c and the line width L24 of the fourth end 32d are greater than the line width L22 of the second end 32b of the second segment trace 32. Furthermore, the line width of the first end 32a of the second segment trace 32 is greater than the line width of the second end 32b of the second segment trace 32. The effect achieved by this line width of the second segment trace 32 is similar to the effect of the line width setting of the second segment trace 32 described above, and will not be repeated here.

[0103] In some embodiments, referring to Figures 3 and 4, the first part 321 includes a first side 321a and a second side 321b opposite to each other in the first direction X, and the second part 322 includes a third side 322a and a fourth side 322b opposite to each other in the first direction X; the first direction X is perpendicular to the direction from the first end 32a to the second end 32b of the second segment trace 32; one end of the first side 321a is connected to one end of the third side 322a, and one end of the second side 321b is connected to one end of the fourth side 322b.

[0104] For example, referring to Figures 3 and 4, one end of the first side 321a is connected to one end of the third side 322a, and one end of the second side 321b is connected to one end of the fourth side 322b. That is, one end of the first side 321a and one end of the third side 322a can intersect at the same point, and one end of the second side 321b and one end of the fourth side 322b intersect at the same point. The included angle formed between the first side 321a and the third side 322a is an obtuse angle, and the included angle formed between the second side 321b and the fourth side 322b is an obtuse angle.

[0105] It should be noted that, referring to Figures 3 and 4, the first part 321 and the second part 322 are arranged opposite to each other and connected. The first part 321 and the second part 322 do not overlap in the orthographic projection of the substrate 1. It can be understood that the end of the first part 321 near the second part 322 and the end of the second part 322 near the first part 321 can be in direct contact.

[0106] For example, referring to FIG3, the dimensions of the first part 321 and the second part 322 in the second direction Y can be the same, and referring to FIG4, the dimensions of the first part 321 and the second part 322 in the second direction Y can also be different. For example, when etching the areas corresponding to the first part 321 and the second part 322 using an exposure and development process, this can be achieved by adjusting the exposure angle of the exposure machine.

[0107] In some embodiments, as shown in FIG5, the first part 321 near the end of the second part 322 partially overlaps with the second part 322 near the end of the first part 321; the portion of the first part 321 near the end of the second part 322 protrudes on the first side F1 of the second segment trace 32; the portion of the second part 322 near the end of the first part 321 protrudes on the second side F2 of the second segment trace 32.

[0108] For example, as shown in FIG5, the end of the first part 321 near the second part 322 partially overlaps with the end of the second part 322 near the first part 321. That is, the overlapping part Q1 can realize the connection between the first part 321 and the second part 322. At the same time, the part Q2 of the first part 321 near the second part 322 that does not overlap with the end of the second part 322 near the first part 321 protrudes on the first side F1 of the second segment 32. The part Q3 of the second part 322 near the first part 321 that does not overlap with the end of the first part 321 near the second part 322 protrudes on the second side F2 of the second segment 32. The directions of the first side F1 and the second side F2 are opposite, and both the directions of the first side F1 and the second side F2 are away from the second segment 32.

[0109] For example, referring to Figure 5, the portion Q2 of the first part 321 near the second part 322 that does not overlap with the portion Q3 of the second part 322 near the first part 321, and the portion Q3 of the second part 322 near the first part 321 that does not overlap with the portion Q3 of the first part 321 near the second part 322, are both stepped. Figure 5 is only one example, where the above connection relationship only needs to ensure that the portion of the first part 321 near the second part 322 partially overlaps with the portion of the second part 322 near the first part 321.

[0110] In some embodiments, as shown in FIG3, the position where the first part 321 and the second part 322 are connected is located at the midpoint of the second segment 32 in the second direction Y; the second direction Y is the direction from the first end 32a to the second end 32b of the second segment 32.

[0111] For example, referring to FIG3, the position where the first part 321 and the second part 322 are connected is located at the midpoint of the second segment 32 in the second direction Y. That is, the dimension H1 of the first part 321 in the second direction Y and the dimension H1 of the second part 322 in the second direction Y can be equal.

[0112] In some embodiments, as shown in FIG3, the ratio of the line width of the first end 32a and / or the second end 32b of the second trace 32 to the average line width L0 of the second trace 32 ranges from 0.75 to 0.85.

[0113] It should be noted that the average line width L0 of the second segment 32 can be the average of the sum of the average line width L10 of the first part 321 and the average line width L20 of the second part 322. For example, L0 = (L10 + L20) / 2. The average line width L10 of the first part 321 can be the average of the sum of the line width L21 of the first end 32a and the line width L23 of the third end 32c of the second segment 32, that is, L10 = (L21 + L23) / 2. The average line width L20 of the second part 322 can be the average of the sum of the line width L22 of the second end 32a and the line width L24 of the fourth end 32d of the second segment 32, that is, L20 = (L22 + L24) / 2.

[0114] For example, the ratio of the line width L21 of the first end 32a of the second segment 32 to the average line width L0 of the second segment 32 is in the range of 0.75, 0.8 or 0.85, etc.

[0115] For example, the ratio of the line width L22 of the second end 32b of the second segment 32 to the average line width L0 of the second segment 32 is in the range of 0.75, 0.8 or 0.85, etc.

[0116] For example, the ratio of the line width L21 of the first end 32a of the second segment 32 to the average line width L0 of the second segment 32 is in the range of 0.75, 0.8 or 0.85, etc., and the ratio of the line width L22 of the second end 32b of the second segment 32 to the average line width L0 of the second segment 32 is in the range of 0.75, 0.8 or 0.85, etc.

[0117] It should be noted that the above ratio range is only an example. Specifically, the ratio includes, but is not limited to, the above values. That is to say, the ratio of the line width of the first end 32a and / or the second end 32b of the second segment 32 to the average line width L0 of the second segment 32 should be within the above range.

[0118] In some embodiments, as shown in FIG6 and in conjunction with FIG3, the substrate 1 further includes a first transition surface 1d connecting the first surface 1a and the side surface 1c, and a second transition surface 1e connecting the second surface 1b and the side surface 1c; the connecting trace 3 further includes a fourth trace 34 disposed on the first transition surface 1d and a fifth trace 35 disposed on the second transition surface 1e, the fourth trace 34 connecting the first trace 31 and the second trace 32, and the fifth trace 35 connecting the second trace 32 and the third trace 33; the line width L41 of the end of the fourth trace 34 connected to the first trace 31 is greater than the line width L42 of the end of the fourth trace 34 connected to the second trace 32; and / or, the line width L51 of the end of the fifth trace 35 connected to the third trace 32 is greater than the line width L52 of the end of the fifth trace 35 connected to the second trace 32.

[0119] For example, the aforementioned side surface 1c is a selected side surface 1cc, and the selected side surface 1cc can be any one of a plurality of side surfaces 1c.

[0120] For example, continuing to refer to FIG6, the first transition surface 1d and the second transition surface 1e are provided, which can enable the connection trace 1 to play a certain buffering role at the bend between the selected side surface 1cc and the first surface 1a, or at the bend between the selected side surface 1cc and the second surface 1b, so as to ensure that the connection trace 3 can stably and smoothly transition between the two opposing main surfaces of the substrate 1, thereby enhancing the reliability of the light-emitting substrate 10.

[0121] For example, as shown in Figure 3, the line width L41 of the end where the fourth segment 34 connects to the first segment 31 is greater than the line width L42 of the end where the fourth segment 34 connects to the second segment 32.

[0122] It should be noted that during the preparation of the fourth segment trace 34, for example, by using an exposure and development process, since the photosensitive film has a higher exposure level at the first end 32a of the corresponding second segment trace 32, the probability of a short circuit occurring at the first end 32a of the second segment trace 32 after exposure and development and subsequent stereolithography coating is greater. Therefore, by setting the above-mentioned line width relationship, it is possible to avoid the situation where the connecting trace 3 short circuits at the end where the fourth segment trace 34 connects to the second segment trace 32.

[0123] For example, as shown in Figure 3, the line width L51 at the end where the fifth segment 35 connects to the third segment 32 is greater than the line width L52 at the end where the fifth segment 35 connects to the second segment 32.

[0124] It should be noted that during the preparation of the fifth trace 35, for example, by using an exposure and development process, since the photosensitive film has a higher exposure level at the second end 32b of the corresponding second trace 32, the probability of a short circuit occurring at the second end 32b of the second trace 32 after exposure and development and subsequent stereolithography coating is greater. Therefore, by setting the above-mentioned line width relationship, it is possible to avoid the situation where the connecting trace 3 is short-circuited at the end where the fifth trace 35 connects to the second trace 32.

[0125] For example, as shown in Figure 3, the line width L41 at the end where the fourth trace 34 connects to the first trace 31 is greater than the line width L42 at the end where the fourth trace 34 connects to the second trace 32; the line width L51 at the end where the fifth trace 35 connects to the third trace 32 is greater than the line width L52 at the end where the fifth trace 35 connects to the second trace 32. The relationship between these line widths is explained in the preceding effect description and will not be repeated here.

[0126] In some embodiments, as shown in FIG3, from the end where the fourth segment 34 is connected to the first segment 31 to the end where the fourth segment 34 is connected to the second segment 32, the line width L4 of the fourth segment 34 gradually decreases; and / or, from the end where the fifth segment 35 is connected to the third segment 33 to the end where the fifth segment 35 is connected to the second segment 32, the line width L5 of the fifth segment 35 gradually decreases.

[0127] For example, the aforementioned variation in the linewidth of the fourth segment 34 and the fifth segment 35 allows for a smooth and uniform transition along the extension direction. It should be noted that setting the linewidth at the end where the fourth segment 34 connects to the first segment 31 to be greater than the linewidth at the end where it connects to the second segment 32 facilitates better overlap between the fourth segment 34 and the first segment 31, increasing the contact area and thus enhancing the conductivity of the fourth segment 34. Similarly, setting the linewidth at the end where the fifth segment 35 connects to the third segment 33 to be greater than the linewidth at the end where it connects to the second segment 32 also facilitates better overlap between the fifth segment 35 and the third segment 33, increasing the contact area and thus enhancing the conductivity of the fourth segment 34.

[0128] In some examples, from the end where the fourth trace 34 connects to the first trace 31 to the end where the fourth trace 34 connects to the second trace 32, the line width L4 of the fourth trace 34 gradually decreases.

[0129] In other examples, from the end where the fifth trace 35 connects to the third trace 33 to the end where the fifth trace 35 connects to the second trace 32, the line width L5 of the fifth trace 35 gradually decreases.

[0130] In some other examples, from the end where the fourth trace 34 connects to the first trace 31 to the end where the fourth trace 34 connects to the second trace 32, the line width L4 of the fourth trace 34 gradually decreases; similarly, from the end where the fifth trace 35 connects to the third trace 33 to the end where the fifth trace 35 connects to the second trace 32, the line width L5 of the fifth trace 35 gradually decreases. The trend of line width variation here is described in the preceding section and will not be repeated here.

[0131] In some embodiments, as shown in FIG3, the line width of the fourth segment 34 satisfies at least one of the following: the line width L41 of the end of the fourth segment 34 connected to the first segment 31 is equal to the line width L1 of the first segment 31; the line width L42 of the end of the fourth segment 34 connected to the second segment 32 is equal to the line width L21 of the first end of the second segment 32; the line width L51 of the end of the fifth segment 35 connected to the third segment 33 is equal to the line width L3 of the third segment 33; the line width L52 of the end of the fifth segment 35 connected to the second segment 33 is equal to the line width L22 of the second end of the second segment 32.

[0132] For example, setting the linewidth L41 of the end where the fourth trace 34 connects to the first trace 31 to be equal to the linewidth L1 of the first trace 31 allows for better overlap between the end where the fourth trace 34 connects to the first trace 31, increasing the contact area and thus enhancing the conductivity between the fourth trace 34 and the first trace 31. Similarly, setting the linewidth L42 of the end where the fourth trace 34 connects to the second trace 32 to be equal to the linewidth L21 of the first end 32a of the second trace 32 allows for better overlap between the end where the fourth trace 34 connects to the second trace 32, increasing the contact area and thus enhancing the conductivity between the fourth trace 34 and the second trace 32. The effect of setting the line width L51 at the end where the fifth trace 35 connects to the third trace 33 is described with reference to the effect of setting the line width L41 at the end where the fourth trace 34 connects to the first trace 31. The effect of setting the line width L52 at the end where the fifth trace 35 connects to the second trace 33 is described with reference to the effect of setting the line width L42 at the end where the fourth trace 34 connects to the second trace 32. These details will not be elaborated here.

[0133] In some embodiments, as shown in FIG3, the average line width L40 of the fourth trace 34 is less than the maximum line width Lmax of the second trace 32; and / or, the average line width L50 of the fifth trace 35 is less than the maximum line width Lmax of the second trace 32.

[0134] For example, the average line width L40 of the fourth segment 34 can be the average of the sum of the line width L41 of the end where the fourth segment 34 is connected to the first segment 31 and the line width L42 of the end where the fourth segment 34 is connected to the second segment 32. For example, L40 = (L41 + L42) / 2. The average line width L50 of the fifth segment 35 can be the average of the sum of the line width L51 of the end where the fifth segment 35 is connected to the third segment 33 and the line width L52 of the end where the fifth segment 35 is connected to the second segment 33. For example, L50 = (L51 + L52) / 2.

[0135] In some examples, as shown in Figure 3, the average linewidth L40 of the fourth trace 34 is less than the maximum linewidth Lmax of the second trace 32. As can be seen from the above, during the preparation of the fourth trace 34, for example, by using an exposure and development process, since the photosensitive film has a higher degree of exposure at the first end 32a of the corresponding second trace 32, the probability of a short circuit occurring at the first end 32a of the second trace 32 after exposure and development and subsequent stereolithography coating is also greater. Referring to Figures 6 and 1, the fourth trace 34 is located only on the first transition surface 1d, while the second trace 32 is located on the selected side surface 1cc. Since the first transition surface 1d connects the first surface 1a and the selected side surface 1cc, the area of ​​the first transition surface 1d is relatively smaller than that of the selected side surface 1cc. It can be understood that the length of the fourth trace 34 located on the first transition surface 1d is less than that of the second trace 32 located on the selected side surface 1cc. In other words, the area of ​​the region with higher exposure during the fabrication of the fourth trace 34 is larger than the area of ​​the region with higher exposure during the fabrication of the second trace 32. Therefore, by setting the above-mentioned linewidth relationship, the above-mentioned short circuit situation can be effectively avoided. In addition, the second trace 32 has a maximum linewidth Lmax, which can ensure the signal transmission capability of the connecting trace 3 in the second trace 32.

[0136] In other examples, continuing to refer to Figure 3, the average line width L50 of the fifth trace 35 is less than the maximum line width Lmax of the second trace 32. The effect of this line width setting is similar to the effect of the average line width L40 of the fourth trace being less than the maximum line width Lmax of the second trace 32. That is, the effect of this line width setting can be referred to the effect of the average line width L40 setting of the fourth trace. It will not be elaborated here.

[0137] In other examples, continuing to refer to Figure 3, the average line width L40 of the fourth trace 34 is less than the maximum line width Lmax of the second trace 32, and the average line width L50 of the fifth trace 35 is less than the maximum line width Lmax of the second trace 32. The effect of the line width settings here combines and refers to the effect of the line width in the two embodiments mentioned above, and will not be elaborated here.

[0138] In some embodiments, referring to FIG7, FIG7 is a cross-sectional structural diagram of a connecting trace 3 according to some embodiments of the present disclosure. In the cross-section of the connecting trace 3, the surface of the connecting trace 3 is arc-shaped; the cross-section is the section of the connecting trace 3 along its extension direction perpendicular to itself.

[0139] It should be noted that during the fabrication of the connection trace 3, the current on the connection trace 3 is relatively large, which easily leads to ion migration. Referring to Figure 8, which is a cross-sectional view of the connection trace 3 in the related art, the cross-section is rectangular, meaning it has a pointed shape. The two points of adjacent connection traces that are close to each other are prone to migration under voltage. During the migration of a large number of ions, short circuits can easily occur at these two points, affecting the lifespan and yield of the display device. In this application, referring to Figure 7, the surface of the connection trace 3 is arc-shaped. This design avoids the cross-section of the connection trace 3 being a smoothly transitioning arc shape without pointed edges, making migration less likely under voltage, further preventing short circuits, and improving the lifespan and yield of the light-emitting substrate 10.

[0140] In some embodiments, referring to FIG9, a bridging structure 8 is further included. The bridging structure 8 is disposed on the second surface 1b. The bridging 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. A plurality of back electrodes 4 are disposed side by side and spaced apart on the fourth surface 8b of the bridging structure 8. A third trace 33 is electrically connected to one of the back electrodes 4. The third trace 33 extends from the second surface 1b through the second side surfaces 8c and the fourth surface 8b to the back electrode 4. The portion of the third trace 33 disposed on the back electrode 4 is the third part 333. Referring to FIG10, the ratio of the dimension s33 of the third part 333 in the third direction Z to the dimension s4 of the back electrode 4 in the third direction Z is 1 / 3 to 1 / 2. The third direction Z is the extension direction of the back electrode 4 and the third trace 33.

[0141] For example, as shown in FIG9, the plurality of second side surfaces 8c include at least one second selected side surface 8cc; each second selected side surface 8cc corresponds to a first selected side surface 1cc. A plurality of back electrodes 4 are disposed side-by-side at intervals on the fourth surface 8b. It should be noted that when the light-emitting substrate 10 includes a bridging structure, the selected side surface 1cc of the substrate 1 is referred to as the first selected side surface 1cc.

[0142] By providing a bridging structure 8 on the second surface 1b of the substrate 1, the bridging structure 8 can serve as a carrier for multiple back electrodes 4. When the light-emitting substrate 10 includes the bridging structure 8, forming multiple back electrodes 4 can be achieved through the following two steps: first, multiple back electrodes 4 are formed on the fourth surface 8b of the bridging structure 8; then, the bridging structure 8 is precisely connected to the second surface 1b of the substrate 1, such that the second surface 1b of the substrate 1 is in contact with the third surface 8a of the bridging structure 8, while the front electrode 2 and the back electrode 4 are aligned in the second direction Y. The process of precisely connecting the bridging structure 8 to the second surface 1b of the substrate 1 is, for example, bonding. This method reduces costs and avoids the impact of etching processes on the front film layer and the device.

[0143] It should be noted that the correspondence between each second selected side surface 8cc and a first selected side surface 1cc means that the number of second selected side surfaces 8cc and the number of selected first side surfaces 1cc are corresponding. Moreover, the second selected side surface 8cc is close to the selected first side surface 1cc corresponding to it, and the two are arranged along the second direction Y.

[0144] It is understood that, as shown in Figure 9, when the light-emitting substrate 10 includes the bridging structure 8, the third segment 33 of the connecting trace 3 includes a portion 331 located on the second surface 1b, a portion 332 located on the second selected side surface 8cc, a portion 334 located on one side of the fourth surface 8b, and a portion located on the back electrode 4. The portion located on the back electrode 4, i.e., the third part 333, extends from the first surface, through the first selected side surface 1cc, to the edge of the second surface 1b, then through the second side surface 8cc, and extends to the fourth surface 8b. In this case, the portions 333 on the fourth surface 8b of the third segment 33 of multiple connecting traces 3 are electrically connected to multiple back electrodes 4 in a one-to-one correspondence.

[0145] The aforementioned bridging structure 8 can enhance the conductive area between the third segment trace 33 and the back electrode 4. That is, the third segment trace 33 can contact the bridging structure 8 through a portion 332 on the second selected side surface 8cc, or the third segment trace 33 can contact the bridging structure 8 through the third portion 333, thereby achieving an electrical connection between the third segment trace 33 and the back electrode 4 through the bridging structure 8.

[0146] For example, the ratio of the dimension s33 of the third part 333 in the third direction Z to the dimension s8 of the bridging structure 8 in the third direction Z can be 1 / 3, 2 / 5, or 1 / 2, etc. There is no specific limitation here, as long as it is within the above ratio range, thereby ensuring the electrical connection between the third trace 33 and the back electrode 4, improving the transmission performance of electrical signals, and thus improving the quality of the display device.

[0147] In some embodiments, continuing to refer to FIG10, the dimension L33 of the third part 333 in the first direction X is the same as the dimension L8 of the bridging structure 8 and the back electrode 4 in the first direction X.

[0148] For example, the third part 333 is set to have a dimension L33 in the first direction X that is the same as the dimension L8 of the bridging structure 8 in the first direction X. This can increase the overlap area when the third part 333 and the bridging structure 8 overlap, further enhance conductivity, improve the transmission performance of electrical signals, and thus improve the quality of the display device.

[0149] The following describes the preparation method of the light-emitting substrate.

[0150] The light-emitting devices in the aforementioned light-emitting substrate 100 are, for example, Micro LEDs or Mini LEDs. Compared to traditional LEDs, these devices have smaller particles, meaning they are smaller in size. Therefore, with a fixed area of ​​the light-emitting substrate 10, more and denser light-emitting devices can be mounted on it, resulting in denser connection traces 3. This places higher demands on the precision and speed of the connection trace fabrication process. In some embodiments, the connection traces are formed using a laser etching patterning process. However, this process has lower precision and slower speed, which is not conducive to the fabrication of connection traces 3 in Micro LED and Mini LED display panels 100. In other embodiments, the connection traces are formed using a three-exposure process, which can lead to large alignment errors at the splicing positions of the formed connection traces, and may even cause the splicing positions of the connection traces to be broken. Therefore, it is necessary to redesign the exposure pattern of the exposure machine.

[0151] Some embodiments of this application provide a method for fabricating a light-emitting substrate, which reduces production costs through a two-exposure process and further reduces the alignment error of the connection traces by reducing the number of splicing operations. As shown in Figures 11A to 11D, the method for fabricating the light-emitting substrate 10 includes:

[0152] S1. As shown in Figure 11A, a photoresist layer 101 is formed on the first surface 1a, the target side surface 1c, and the second surface 1b of the substrate 1. The substrate 1 includes a first end 11 and a second end 12 opposite to each other, and the first end 11 is the end where the target side surface 1c is located.

[0153] For example, at least one of the plurality of side surfaces 1c of the substrate 1 is a selected side surface 1cc, for example, a target side surface 1c is a selected side surface 1cc.

[0154] For example, the material of substrate 1 is a rigid material such as glass or quartz.

[0155] S2. As shown in Figure 11B, the photoresist layer 101 is exposed twice and then developed to expose the area where the connection trace 3 is to be formed.

[0156] It is understandable that the exposure and development process can etch away the area in the photoresist layer 101 where the connection line 3 is to be formed, thus exposing the area P where the connection line 3 is to be formed.

[0157] S3. As shown in Figure 11C, material for the connecting trace 3 is deposited on the first surface 1a, the target side surface 1c, and the second surface 1b of the substrate 1.

[0158] For example, the above deposition process can be a stereolithography deposition process, and the material of the connecting trace 3 is a metal material.

[0159] S4. As shown in Figure 11D, the photoresist layer is peeled off to form multiple connection traces 3. Referring to Figure 1, the connection traces 3 include a first trace 31 disposed on the first surface 1a, a second trace 32 disposed on the side surface 1c, and a third trace 33 disposed on the second surface 1b. The line width L21 of the first end 32a of the second trace 32 is smaller than the line width L1 of the first trace 31, and the line width L22 of the second end 32b of the second trace 32 is smaller than the line width L3 of the third trace 33.

[0160] For example, as described above, the photoresist layer 101 has a higher exposure level at the positions corresponding to the first end 32a and the second end 32b of the second segment of the trace 32. After exposure and development, the probability of the connecting trace 3 formed by the stereo sputtering deposition process short-circuiting at the positions corresponding to the first end 32a and the second end 32b of the second segment of the trace 32 is also greater. Therefore, by setting the above-mentioned line width relationship, it is possible to avoid the connecting trace 3 short-circuiting at the positions corresponding to the first end 32a and the second end 32b of the second segment of the trace 32.

[0161] It should be noted that, referring to Figure 12, the photoresist layer 101 can be directly attached to the first surface 1a, the target side surface 1c, and the second surface 1b of the substrate 1. However, during the attachment process, there is a floating phenomenon. When depositing the material of the connection trace 3, some material will enter the floating area of ​​the photoresist layer 101. This will cause the connection trace 3 formed after metal deposition to be thick in the middle and thin at the edges. Referring to Figure 7, the surface of the connection trace 3 is arc-shaped. When the cross-section of the connection trace 3 is arc-shaped, there is no sharp point. Under the action of voltage, ion migration is not easy to occur, further avoiding short circuits and improving the service life and yield of the light-emitting substrate 10.

[0162] In some embodiments, as shown in Figures 13A to 13D, step S2 specifically includes:

[0163] S21. As shown in Figure 13A, the substrate 1 is tilted relative to the base, the first surface 1a of the substrate 1 is farther away from the base than the second surface 1b, and the first end 11 of the substrate 1 is higher than the second end 12 of the substrate 1.

[0164] For example, a pad is provided between the substrate 1 and the base, and the pad makes the substrate 1 and the base have a certain angle. In order to ensure that the first surface 1a of the substrate 1 and the target side surface 1c of the substrate 1 can be fully exposed, the angle range can be 1 to 45°.

[0165] S22. As shown in FIG13B, the first target region A1 of the photoresist layer 101 on the first surface 1a and the target side surface 1c of the substrate 1 is exposed.

[0166] For example, referring to FIG13B and in conjunction with FIG3, the first target area A1 is the area corresponding to the first part 321 that forms the first segment 31, the fourth segment 34 and the second segment 32.

[0167] S23. As shown in Figure 13C, flip the substrate 1 so that the second surface 1b of the substrate 1 is farther away from the base than the first surface 1a, and keep the substrate 1 tilted relative to the base, with the first end 11 of the substrate 1 higher than the second end 12 of the substrate 1.

[0168] For example, the above-mentioned flipping method is the flipping of the positions of the first surface 1a and the second surface 1b of the substrate 1, for example, the flipping angle is 180°.

[0169] S24. As shown in Figure 13D, in conjunction with Figure 3, the second target region A2 of the photoresist layer 101 on the second surface 1b and the target side surface 1c of the substrate 1 is exposed.

[0170] For example, referring to FIG13D, the second target area A2 is the area corresponding to the second part 322 that forms the third segment 33, the fifth segment 35 and the second segment 32.

[0171] The above describes the fabrication process of forming the interconnect traces 3 in the light-emitting substrate 10. The fabrication process of the light-emitting substrate 10 includes steps R1 to R5 before forming the interconnect traces 3:

[0172] R1 provides substrate 1.

[0173] As shown in FIG2, the substrate 1 includes a first surface 1a and a second surface 1b opposite to each other, and a plurality of side surfaces 1c connecting the first surface 1a and the second surface 1b, wherein at least one of the plurality of side surfaces 1c is a selected side surface 1cc.

[0174] R2, as shown in Figure 2, multiple front electrodes 2 are formed on the first surface 1a of the substrate 1 in parallel and spaced apart, with the multiple front electrodes 2 close to the selected side surface 1cc.

[0175] R3, as shown in Figure 9, a bridging structure 8 is formed on the second surface 1b of the substrate 1.

[0176] The bridging 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 close to the substrate 1 relative to the fourth surface 8b; the plurality of second side surfaces 8c includes at least one second selected side surface 8cc; each second selected side surface 8cc corresponds to a first selected side surface 1cc.

[0177] R4, as shown in Figure 9, multiple back electrodes 4 are formed on the bridging structure 8, and the multiple back electrodes 4 are close to the second selected side surface 8cc.

[0178] It should be noted that, in the above exposure process, referring to Figures 13A and 13C, and in conjunction with Figure 3, the exposure machine is located obliquely above the first transition surface 1d and the second transition surface 1e. Consequently, due to the lower exposure energy in the area where the first segment 31 and the third segment 33 are located away from the exposure machine, the photoresist layer 101 may not be completely etched. As a result, the side of the first segment 31 and the third segment 33 away from the exposure machine will have an undercut structure of the connecting trace 3 as shown in Figure 14A, that is, part of the connecting trace 3 in the figure is missing, or, as shown in Figure 14B, one side of the connecting trace 3 will be arc-shaped. Figures 14A and 14B are both cross-sectional views obtained by taking a section along the extension direction of the connecting trace 3.

[0179] Therefore, as shown in Figure 9, by providing the bridging structure 8, the connection trace 3 can be made to contact the bridging structure 8, thereby ensuring the electrical connection between the connection trace 3 and the back electrode 4. For example, the thickness of the bridging structure 8 is greater than the thickness of the back electrode 4, which helps to increase the contact area between the bridging structure 8 and the back electrode 4. For instance, both the second selected side surface 8cc and the fourth surface 8b of the bridging structure 8 are in contact with the connection trace 3.

[0180] In some embodiments, as shown in Figures 13B and 13D, the photoresist layer 101 is made of negative photoresist; the first target region A1 and the second target region A2 include the region between the interconnecting traces 3 to be formed.

[0181] For example, the material of the photoresist layer 101 is a negative photoresist. That is, under the two exposures of the exposure machine, the area between the connection traces 3 to be formed in the first target area A1 and the second target area A2 is exposed, and then the corresponding unexposed areas in the first target area A1 and the second target area A2 are removed by the developer. In other words, the corresponding unexposed areas in the first target area A1 and the second target area A2 are the areas where the connection traces 3 are to be formed.

[0182] It should be noted that, since the exposure machine is close to the first end 32a and the second end 32b of the second segment 32, the exposure level is relatively high. The exposed area is the region between the connecting lines 3 to be formed. In this case, the area between the connecting lines 3 to be formed will increase in exposure area due to the increased exposure level. When developing and removing the region of the connecting lines 3 to be formed, the width of the removed part is relatively narrower than the region with lower exposure level. At this time, during the process of forming the connecting lines 3 by the deposition process, the line width of the formed connecting lines 3 is narrower at the position where the width of the region forming the connecting lines 3 becomes narrower. Therefore, the line width L21 of the first end 32a of the second segment 32 is smaller than the line width L1 of the first segment 31, and the line width L22 of the second end 32b of the second segment 32 is smaller than the line width L3 of the third segment 33. In other words, the interconnecting traces 3 obtained by exposure, development, and deposition using negative photoresist can naturally form the aforementioned linewidth relationship, without needing to reset the opening shape of the exposure machine, thus simplifying the process and reducing costs.

[0183] In some embodiments, as shown in FIG15, the opening of the mask 20 used for exposure includes a first portion 20a and a second portion 20b arranged and connected along a first preset direction G1. The size of the first portion 20a along the second preset direction G2 is larger than the size of the second portion 20b along the second preset direction G2. The second preset direction G2 is perpendicular to the first preset direction G1. During the exposure process, the second portion 20b of the opening of the mask 20 corresponds to the photoresist layer 101 on the target side surface 1c.

[0184] For example, referring to FIG15, the opening of the photomask 20 includes a second portion 20b extending along a first preset direction G1 and a first portion 20a extending along a second preset direction G2. The size h1 of the first portion 20a along the second preset direction G2 is greater than the size h2 of the second portion 20b along the second preset direction G2. That is, in the photoresist layer 101 exposed by the photomask 20, the exposure area of ​​the region corresponding to the first portion 20a of the photomask 20 is greater than the exposure area of ​​the region corresponding to the second portion 20b of the photomask 20. Thus, in conjunction with FIG3 and FIG13A, in the connection trace 3 deposited after development by negative photoresist, the linewidth of the connection trace 3 formed adjacent to the region corresponding to the first portion 20a of the opening of the photomask 20 is smaller than the linewidth of the connection trace 3 formed adjacent to the region corresponding to the second portion 20a of the opening of the photomask 20. For example, the opening shape of the mask 20 is "L". Since the second part 20b of the opening of the mask 20 corresponds to the target side surface 1c, this setting can increase the contact area between the first part 321 and the second part 322 formed on the target side surface 1c during the two exposure processes (the splicing position), which facilitates better overlap of the first part 321 and the second part 322 and improves the transmission efficiency of electrical signals.

[0185] The embodiments of this disclosure also provide a display panel 100, which has the same technical effects as the light-emitting substrate 10 described above, and will not be described in detail here.

[0186] For example, the display panel 100 includes a display area AA and a peripheral area BB disposed on at least one side of the display area AA. For example, the peripheral area BB may be located on one, two, or three sides of the display area AA, or the peripheral area BB may be disposed around the display area AA.

[0187] For example, the first surface 1a of the substrate 1 is the front side of the substrate 1, corresponding to the display side of the display panel 100, and the second surface 1b of the substrate 1 is the back side of the substrate, corresponding to the non-display side of the display panel 100.

[0188] The embodiments of this disclosure also provide a display device 1000, and there are no special limitations on the specific form of the display device 1000. Referring to FIG16, the display device 1000 includes a display panel 100 as described in the above embodiments. Therefore, the display device 1000 provided by this disclosure has all the beneficial effects of the display panel 100 provided in any of the above embodiments, which will not be described in detail here.

[0189] For example, referring to FIG17, the display device 1000 further includes a driving circuit board 200, which is electrically connected to the display panel 100. For example, the driving circuit board 200 is electrically connected to the back electrode of the display panel 100 through a flexible circuit board 9. The electrical signal provided by the driving circuit board 200 is transmitted to the driving circuit layer of the display panel 100 through the flexible circuit board 9, the back electrode 4, the connecting trace 3 and the front electrode 2 to control the light-emitting device to emit light. The driving circuit board 200 is configured to drive the display panel 100 to display images.

[0190] For example, the driving circuit board 200 and the flexible circuit board 9 are bonded to the non-display side of the display panel 100, that is, the driving circuit board 200 and the flexible circuit board 9 are bonded to the second surface 1b of the substrate 1. Electronic components located on the display side of the display panel 100 (the first surface 1a of the substrate 1) are electrically connected to the driving circuit board 200 via multiple connection traces 3, front electrode 2, and back electrode 4. This reduces the bezel of the display device 1000, increases the screen-to-body ratio of the display device 1000, and facilitates a seamless splicing effect.

[0191] For example, the above-mentioned display device 1000 can be any one of a light-emitting diode (LED) display device, a mini light-emitting diode (Mini LED) display device, or a micro light-emitting diode (Micro LED) display device, and this disclosure does not specifically limit it.

[0192] Exemplarily, the display device 1000 can be any device that displays images, whether moving (e.g., video) or stationary (e.g., still images), and whether text or images. More specifically, the embodiments described are contemplated to be implemented in or associated with a variety of electronic devices, such as (but not limited to) mobile phones, wireless devices, personal digital assistants (PDAs), handheld or portable computers, GPS receivers / navigators, cameras, MP4 video players, camcorders, game consoles, watches, clocks, calculators, television monitors, flat panel displays, computer monitors, automotive displays (e.g., odometer displays, etc.), navigators, augmented reality (AR) devices, virtual reality (VR) devices, cockpit controllers and / or displays, displays of camera views (e.g., displays of rearview cameras in vehicles), electronic photographs, electronic billboards or signs, projectors, architectural structures, packaging and aesthetic structures (e.g., displays of images of a piece of jewelry), and any product or component with display functionality. For example, as shown in FIG15, the display device 1000 can be a mobile phone.

[0193] The above-described display device uses a mobile phone as an example to illustrate some embodiments of this disclosure. However, the implementation of this disclosure is not limited to this, and any other display device can be considered as long as the same technical concept is applied.

[0194] For example, the display device 1000 may also include a frame and other electronic components. The display panel 100 may, for example, be disposed within the frame.

[0195] Some embodiments of this disclosure also provide a splicing display device 10000, as shown in Figures 18 and 20. The splicing display device 10000 includes a plurality of display devices 1000 as provided in the above embodiments.

[0196] As exemplarily shown in Figures 18 and 20, the multiple display devices 1000 in the splicing display device 10000 are arranged in an array. The splicing display device 10000 can display a large screen, and can be used, for example, as an advertising splicing screen, a conference splicing screen, etc.

[0197] For example, as shown in Figures 18 and 20, the display device 1000 is rectangular.

[0198] Referring to Figure 2, in the display panel 100, a plurality of front electrodes 2 are arranged side-by-side at intervals along a first direction X. Correspondingly, a plurality of connecting lines 3 are also arranged side-by-side at intervals along the first direction X. The plurality of front electrodes 2 extend along a third direction Z, which is parallel to the display device 1000 and perpendicular to the first direction X. The display device 1000 includes a plurality of sides. Hereinafter, the side of the display device 1000 closest to the plurality of front electrodes 2 will be referred to as a selected side of the display device 1000.

[0199] For example, as shown in FIG2, the display panel 100 includes a display area AA and two bonding areas CC located on opposite sides of the display area AA. The display panel 100 includes two sets of front electrodes 2, each set of front electrodes 2 including multiple upper electrodes 2, and the two sets of front electrodes 2 are respectively disposed close to the two bonding areas CC.

[0200] Furthermore, as shown in Figure 18, when splicing multiple display devices 1000 including the display panel 100 shown in Figure 2, the selected side surfaces of two adjacent display devices 1000 are both arranged along the first direction X. In this way, among the multiple display devices 1000 arranged in a row along the first direction X, there is basically no seam between two adjacent display devices 1000 along the first direction X; among the multiple display devices 1000 arranged in a column along the third direction Z, there is a splicing gap between two adjacent display devices 1000. That is to say, the size of the splicing gap between two adjacent display devices 1000 in the multiple display devices 1000 arranged in a row along the first direction X is smaller than the size of the splicing gap between two adjacent display devices 1000 in the multiple display devices 1000 arranged in a column along the third direction Z.

[0201] However, the size of the bonding area CC in the third direction Z is very small. Therefore, when actually viewing the splicing display device 10000, the seam between two adjacent display devices 1000 is difficult to be seen by the naked eye within the viewing distance. This makes the display image of the splicing display device 10000 more complete and can present a better display effect.

[0202] Some embodiments of this disclosure also provide a splicing display device 10000, as shown in FIG19, the splicing display device 1000 including a plurality of display panels 100 as provided in the above embodiments.

[0203] For example, as shown in FIG19, the display panel 100 includes a display area AA and a bonding area CC located on one side of the display area AA, and a plurality of front electrodes 2 are disposed in the bonding area CC.

[0204] Furthermore, as shown in Figure 20, when splicing multiple display devices 1000 including the display panel 100 shown in Figure 19, the selected sides of two adjacent display devices 1000 are arranged along the first direction X. In this way, among the multiple display devices 1000 arranged in a row along the first direction X, there is basically no seam between two adjacent display devices 1000 along the first direction X; among the multiple display devices 1000 arranged in a column along the third direction Z, there is a splicing gap between two adjacent display devices 1000. That is to say, the size of the splicing gap between two adjacent display devices 1000 in the multiple display devices 1000 arranged in a row along the first direction X is smaller than the size of the splicing gap between two adjacent display devices 1000 in the multiple display devices 1000 arranged in a column along the third direction Z.

[0205] However, the size of the bonding area CC in the third direction Z is very small. Therefore, when actually viewing the splicing display device 10000, the seam between two adjacent display devices 1000 is difficult to be seen with the naked eye within the viewing distance. This makes the display image of the splicing display device 10000 more complete and can present a better display effect.

[0206] The splicing display device 10000 adopts the display device 1000 provided in the above embodiment and has the same technical effect as the display device 1000 described above, which will not be elaborated here.

[0207] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A light-emitting substrate, comprising: A substrate, the substrate including a first surface and a second surface disposed opposite to each other, and a side surface connecting the first surface and the second surface; Multiple connection traces are arranged side-by-side and spaced apart; the connection traces extend from the first surface through the side surface to the second surface, and the connection traces include a first trace disposed on the first surface, a second trace disposed on the side surface, and a third trace disposed on the second surface. The second segment of the trace includes a first end near the first segment of the trace and a second end near the third segment of the trace; the line width of the first end of the second segment of the trace is smaller than the line width of the first segment of the trace, and the line width of the second end of the second segment of the trace is smaller than the line width of the third segment of the trace.

2. The light-emitting substrate according to claim 1, wherein, The ratio of the line width of the first end of the second segment to the line width of the first segment ranges from 0.75 to 0.

85.

3. The light-emitting substrate according to claim 1 or 2, wherein, The ratio of the line width of the second end of the second segment to the line width of the third segment ranges from 0.75 to 0.

85.

4. The light-emitting substrate according to claim 1 or 2, wherein, The ratio of the line width at the second end of the second segment to the line width of the third segment ranges from 1 / 3 to 1 / 2.

5. The light-emitting substrate according to any one of claims 1 to 4, wherein, The line width at the first end of the second segment is greater than the line width at the second end.

6. The light-emitting substrate according to any one of claims 1 to 3, wherein, The line width at the first end and the line width at the second end of the second segment are equal.

7. The light-emitting substrate according to any one of claims 1 to 6, wherein, The second segment of the trace includes a first part and a second part connected together. The end of the first part away from the second part is the first end of the second segment of the trace, and the end of the second part away from the first part is the second end of the second segment of the trace. From the first end of the second segment to the end where the first part connects to the second part, the line width of the first part gradually increases; From the second end of the second segment to the end where the second part connects to the first part, the line width of the second part gradually increases.

8. The light-emitting substrate according to claim 7, wherein, The first part includes a first side and a second side opposite to each other in a first direction, and the second part includes a third side and a fourth side opposite to each other in the first direction; the first direction is perpendicular to the direction from the first end to the second end of the second segment of the trace; One end of the first side is connected to one end of the third side, and one end of the second side is connected to one end of the fourth side.

9. The light-emitting substrate according to claim 8, wherein, The end of the first part near the second part partially overlaps with the end of the second part near the first part; The portion of the first part near one end of the second part protrudes on the first side of the second segment of the trace; The portion of the second part near one end of the first part protrudes on the second side of the second segment of the trace.

10. The light-emitting substrate according to any one of claims 7 to 9, wherein, The position where the first part and the second part are connected is located at the midpoint of the second segment of the trace in the second direction; the second direction is the direction from the first end to the second end of the second segment of the trace.

11. The light-emitting substrate according to any one of claims 1 to 10, wherein, The ratio of the line width of the first end and / or the second end of the second segment to the average line width of the second segment ranges from 0.75 to 0.

85.

12. The light-emitting substrate according to any one of claims 1 to 11, wherein, The substrate further includes a first transition surface connecting the first surface and the side surface, and a second transition surface connecting the second surface and the side surface; The connection trace further includes a fourth trace disposed on the first transition surface and a fifth trace disposed on the second transition surface. The fourth trace connects the first trace and the second trace, and the fifth trace connects the second trace and the third trace. The line width at the end where the fourth segment connects to the first segment is greater than the line width at the end where the fourth segment connects to the second segment; and / or, The line width at the end where the fifth segment connects to the third segment is greater than the line width at the end where the fifth segment connects to the second segment.

13. The light-emitting substrate according to claim 12, wherein, From the end where the fourth trace connects to the first trace to the end where the fourth trace connects to the second trace, the trace width of the fourth trace gradually decreases; and / or, From the end where the fifth trace connects to the third trace to the end where the fifth trace connects to the second trace, the line width of the fifth trace gradually decreases.

14. The light-emitting substrate according to claim 12 or 13, wherein, The line width of the fourth segment of the trace must satisfy at least one of the following: The line width of the end of the fourth trace that connects to the first trace is equal to the line width of the first trace. The line width at the end where the fourth segment connects to the second segment is equal to the line width at the first end of the second segment. The line width at the end where the fifth segment connects to the third segment is equal to the line width of the third segment. The line width at the end where the fifth segment connects to the second segment is equal to the line width at the second end of the second segment.

15. The light-emitting substrate according to any one of claims 12 to 14, wherein, The average line width of the fourth segment is less than the maximum line width of the second segment; and / or, The average line width of the fifth segment is less than the maximum line width of the second segment.

16. The light-emitting substrate according to any one of claims 1 to 15, wherein, In the cross-section of the connecting trace, the surface of the connecting trace is arc-shaped; the cross-section is the section of the connecting trace along its extension direction perpendicular to itself.

17. The light-emitting substrate according to any one of claims 1 to 16, further comprising: Multiple front electrodes are arranged side-by-side and spaced apart on the first surface, and the first segment of each of the multiple connection traces is electrically connected to one of the multiple front electrodes. Multiple light-emitting devices are disposed on the first surface, and the multiple light-emitting devices are far away from the multiple connection traces relative to the multiple front electrodes, and the multiple light-emitting devices are electrically connected to the multiple front electrodes.

18. The light-emitting substrate according to any one of claims 1 to 17, further comprising: A bridging structure is disposed on the second surface, the bridging structure includes 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 is close to the substrate relative to the fourth surface; Multiple back electrodes are arranged side-by-side and spaced apart on the fourth surface of the bridging structure. A third trace is electrically connected to one of the multiple back electrodes. The third trace extends from the second surface, through the second side surface and the fourth surface to the back electrode. The portion of the third trace on the back electrode is the third part. Wherein, the ratio of the dimension of the third part in the third direction to the dimension of the back electrode in the third direction is 1 / 3 to 1 / 2, and the third direction is the extension direction of the back electrode and the third segment of the trace.

19. The light-emitting substrate according to claim 18, wherein the dimension of the third part in the first direction is the same as the dimension of the bridging structure and the back electrode in the first direction.

20. A display panel, comprising: The light-emitting substrate as described in any one of claims 1 to 19.

21. A display device, comprising: The display panel as described in claim 20; A driving circuit board, which is electrically connected to the display panel.

22. A splicing display device, comprising: Multiple interconnected display panels, wherein the display panels are the display panels as described in claim 20; or, Multiple interconnected display devices, wherein the display devices are as described in claim 21.

23. A method for preparing a light-emitting substrate, wherein, include: A photoresist layer is formed on the first surface, the target side surface, and the second surface of the substrate; The substrate includes a first end and a second end opposite to each other, wherein the first end is the end where the target side surface is located; The photoresist layer is exposed twice and then developed to expose the area where the interconnection traces are to be formed; Material for connecting traces is deposited on the first surface, the target side surface, and the second surface of the substrate; The photoresist layer is peeled off to form multiple connection traces; the connection traces include a first trace disposed on the first surface, a second trace disposed on the side surface, and a third trace disposed on the second surface; the line width of the first end of the second trace is smaller than the line width of the first trace, and the line width of the second end of the second trace is smaller than the line width of the third trace.

24. The method for preparing a light-emitting substrate according to claim 23, wherein, The process of exposing the photoresist layer twice includes: The substrate is tilted relative to the base, the first surface of the substrate is farther away from the base than the second surface, and the first end of the substrate is higher than the second end of the substrate; The first target area of ​​the photoresist layer on the first surface and the target side surface of the substrate is exposed; The substrate is flipped so that the second surface of the substrate is farther away from the base than the first surface, while the substrate is kept tilted relative to the base, with the first end of the substrate higher than the second end of the substrate; The second target area of ​​the photoresist layer on the second surface and the target side surface of the substrate is exposed.

25. The method for preparing a light-emitting substrate according to claim 24, wherein, The photoresist layer is made of negative photoresist; The first target area and the second target area include the area between the connection traces to be formed.

26. The method for preparing a light-emitting substrate according to any one of claims 23 to 25, wherein, The opening of the mask used for the exposure includes a first part and a second part arranged and connected along a first preset direction, wherein the size of the first part along the second preset direction is larger than the size of the second part along the second preset direction; The second preset direction is perpendicular to the first preset direction; During the exposure process, the first portion of the opening in the mask corresponds to the photoresist layer on the target side surface.

Images