Light emitting substrate, display device, and method of manufacturing light emitting substrate

Abstract

A light emitting substrate is provided. The light emitting substrate includes: a first substrate having a plurality of light emitting elements and a plurality of circuit signal lines; a flexible printed circuit and / or a second substrate on the first substrate; and one or more connecting lines and one or more signal lines electrically connecting the plurality of circuit signal lines and the flexible printed circuit together. The one or more signal lines are located on a side of the second substrate and / or the flexible printed circuit close to the first substrate and on a side of the first substrate close to the second substrate and / or the flexible printed circuit. The one or more connection lines are connected to the one or more signal lines. One or more signal lines are connected to the flexible printed circuit.

Description

Technical Field

[0001] This invention relates to display technology, and more particularly to a light-emitting substrate, a display device, and a method for manufacturing the light-emitting substrate. Background Technology

[0002] Mini-LED technology is characterized by its ability to provide higher brightness, better contrast, and improved energy efficiency, and has become a leading solution in the display industry. Integrating mini-LEDs into glass substrates, combined with advanced circuit design, has allowed for the production of thinner, lighter, and more robust displays. Summary of the Invention

[0003] On one hand, this disclosure provides a light-emitting substrate, comprising: a first substrate having a plurality of light-emitting elements and a plurality of circuit signal lines; a flexible printed circuit and / or a second substrate, the flexible printed circuit and / or the second substrate being located on the first substrate; and one or more connecting lines and one or more signal lines, the one or more connecting lines and the one or more signal lines electrically connecting the plurality of circuit signal lines and the flexible printed circuit together; wherein, the one or more signal lines are located on the side of the second substrate and / or the flexible printed circuit closer to the first substrate, and on the side of the first substrate closer to the second substrate and / or the flexible printed circuit; the one or more connecting lines are connected to the one or more signal lines; the one or more signal lines are connected to the flexible printed circuit; a first portion of the one or more connecting lines is located on the first substrate; a second portion of the one or more connecting lines is attached to a lateral side of the first substrate; and a third portion of the one or more connecting lines is located on the side of the first substrate closer to the one or more signal lines, and on the side of the one or more signal lines closer to the first substrate.

[0004] Optionally, the light-emitting substrate includes both the second substrate and the flexible printed circuit; wherein the second substrate is located on the first substrate; the flexible printed circuit is located on the side of the second substrate closer to the first substrate, and on the side of the first substrate closer to the second substrate; the one or more signal lines are located on the side of the second substrate closer to the first substrate, and on the side of the first substrate closer to the second substrate; and the one or more signal lines are attached to the second substrate.

[0005] Optionally, the second substrate is made of an inorganic insulating material; and the ratio of the thickness of the second substrate to the thickness of the first substrate is in the range of 0.6 to 1.0.

[0006] Optionally, the thickness of the second substrate is in the range of 0.3 mm to 0.5 mm.

[0007] Optionally, along a plane intersecting the first substrate, the second substrate, the one or more signal lines, and the one or more connecting lines, the one or more signal lines and the one or more connecting lines are in contact with each other along a first distance; wherein, the first substrate includes a first surface and a second surface, the third portion of the one or more connecting lines is placed on the first surface, and the second portion of the one or more connecting lines is placed on the second surface; the first substrate includes a chamfered portion located between the first surface and the second surface, the chamfered portion having a chamfered edge; along a plane intersecting the first substrate, the second substrate, the one or more signal lines, and the one or more connecting lines, a second distance between the orthographic projection of the edge of the second substrate on the first surface and the line between the first surface and the chamfered portion is less than the first distance; and along a plane intersecting the first substrate, the second substrate, the one or more signal lines, and the one or more connecting lines, a third distance between the line between the first surface and the chamfered portion and the orthographic projection of the second surface on a plane including the first surface is greater than the second distance and less than the first distance.

[0008] Optionally, the alignment accuracy a1 between the first substrate and the second substrate is ±5 μm; the polishing accuracy a2 of the first substrate is ±15 μm; the polishing accuracy a3 of the second substrate is ±15 μm; and the...

[0009] Optionally, the light-emitting substrate further includes a second conductive adhesive layer; wherein the one or more signal lines are connected to the flexible printed circuit through the second conductive adhesive layer.

[0010] Optionally, the light-emitting substrate further includes an adhesive layer for attaching the second substrate to the first substrate.

[0011] Optionally, the light-emitting substrate further includes a pad layer located on the side of the one or more signal lines away from the second substrate; wherein the pad layer partially covers the one or more signal lines; the light-emitting substrate includes a plurality of slits; the pad layer includes a plurality of baffles; the plurality of slits and the plurality of baffles are alternately arranged; the one or more signal lines include one or more terminal leads connected to the one or more connecting lines; and each slit in the plurality of slits exposes a corresponding terminal lead in the one or more terminal leads.

[0012] Optionally, along the direction spanning the plurality of retaining walls and the plurality of slits, the width of each of the plurality of retaining walls is greater than 15 μm.

[0013] Optionally, the one or more signal lines include one or more bonding leads configured to bond to the flexible printed circuit; each bonding lead of the one or more bonding leads is located at the opposite end of a corresponding terminal lead of the one or more signal lines; and the orthographic projection of the pad on the substrate does not overlap with the orthographic projection of the one or more bonding leads on the substrate.

[0014] Optionally, the light-emitting substrate includes: the flexible printed circuit located on the first substrate; and an adhesive layer that attaches the flexible printed circuit to the first substrate; wherein the one or more signal lines are located on the side of the flexible printed circuit closer to the first substrate, and on the side of the first substrate closer to the flexible printed circuit.

[0015] Optionally, the one or more signal lines are in direct contact with the one or more connecting lines.

[0016] Optionally, the light-emitting substrate further includes a first conductive adhesive layer; wherein the one or more signal lines are connected to the one or more connecting lines through the first conductive adhesive layer.

[0017] Optionally, the second and third portions of the one or more connecting lines are in direct contact with the first substrate.

[0018] Optionally, the light-emitting substrate further includes a protective layer covering the one or more connecting lines; wherein the protective layer includes a sealing portion that contacts the second substrate and the one or more connecting lines; and the sealing portion is at least partially located on the lateral side of the second substrate.

[0019] On the other hand, this disclosure provides a light-emitting substrate, comprising: a first substrate having a plurality of light-emitting elements and a plurality of circuit signal lines; a second substrate located on the first substrate; a flexible printed circuit located on a side of the second substrate away from the first substrate; one or more connecting lines and one or more signal lines, the one or more connecting lines and the one or more signal lines connecting the plurality of circuit signal lines and the flexible printed circuit together; wherein the one or more connecting lines are connected to the one or more signal lines; the one or more signal lines are connected to the flexible printed circuit; the one or more signal lines are located on a side of the second substrate away from the first substrate; a first portion of the one or more connecting lines is located on the first substrate; a second portion of the one or more connecting lines is attached to a lateral side of the first substrate; a third portion of the one or more connecting lines is attached to a lateral side of the second substrate; and a fourth portion of the one or more connecting lines is located on a side of the one or more signal lines away from the second substrate.

[0020] Optionally, the second substrate includes a first surface and a second surface, the fourth portion of the one or more signal lines and the one or more connecting lines is placed on the first surface, and the third portion of the one or more connecting lines is placed on the second surface; the second substrate includes a chamfered portion located between the first surface and the second surface, the chamfered portion having a chamfered edge; the first substrate includes a third surface, the second portion of the one or more connecting lines is placed on the third surface; and the second surface and the third surface are substantially flat.

[0021] On the other hand, this disclosure provides a display device including a light-emitting substrate described herein or manufactured by the methods described herein, and one or more integrated circuits connected to the light-emitting substrate.

[0022] On the other hand, this disclosure provides a method for manufacturing a light-emitting substrate, comprising: providing a first substrate having a plurality of light-emitting elements and a plurality of circuit signal lines; attaching a flexible printed circuit and / or a second substrate to the first substrate; and forming one or more connecting lines and one or more signal lines connecting the plurality of circuit signal lines and the flexible printed circuit together; wherein the one or more signal lines are formed on a side of the second substrate and / or the flexible printed circuit near the first substrate and on a side of the first substrate near the second substrate and / or the flexible printed circuit; the one or more connecting lines are connected to the one or more signal lines; the one or more signal lines are connected to the flexible printed circuit; a first portion of the one or more connecting lines is located on the first substrate; a second portion of the one or more connecting lines is attached to a lateral side of the first substrate; and a third portion of the one or more connecting lines is located on a side of the first substrate near the one or more signal lines and on a side of the one or more signal lines near the first substrate. Attached Figure Description

[0023] The following figures are merely illustrative examples based on various disclosed embodiments and are not intended to limit the scope of the invention.

[0024] Figure 1 This is a schematic diagram showing the structure of the relevant display panel.

[0025] Figure 2 This is a floor plan of the relevant display panel.

[0026] Figure 3 It is a magnified view of a region of the relevant display panel.

[0027] Figure 4 It is a microscopic image of the relevant display panel.

[0028] Figure 5 It is a microscopic image of the relevant display panel.

[0029] Figure 6 It is a microscopic image of the relevant display panel.

[0030] Figure 7 These are scanning electron microscope images of the relevant display panel.

[0031] Figure 8 It is a microscopic image of the relevant display panel.

[0032] Figure 9 It is a microscopic image of the relevant display panel.

[0033] Figure 10 This is a schematic diagram illustrating the structure of a display panel according to some embodiments of the present disclosure.

[0034] Figure 11 This is a plan view of a display panel according to some embodiments of the present disclosure.

[0035] Figure 12 This is an exploded view of a display panel according to some embodiments of the present disclosure.

[0036] Figure 13 This is an enlarged view of the display panel according to some embodiments of the present disclosure.

[0037] Figure 14 This is an enlarged view of a first substrate in a display panel according to some embodiments of the present disclosure.

[0038] Figure 15 This illustrates the connection between one or more connecting lines and one or more terminal leads on a second substrate in a display panel according to some embodiments of the present disclosure.

[0039] Figure 16 This is a plan view of a portion of a display panel according to some embodiments of the present disclosure.

[0040] Figure 17 This is a cross-sectional view of a portion of a display panel according to some embodiments of the present disclosure.

[0041] Figure 18 This is a schematic diagram illustrating the structure of a display panel according to some embodiments of the present disclosure.

[0042] Figure 19 This is a schematic diagram illustrating the structure of a display panel according to some embodiments of the present disclosure.

[0043] Figure 20 This is a schematic diagram illustrating the structure of a display panel according to some embodiments of the present disclosure.

[0044] Figure 21 This is a schematic diagram illustrating the structure of a display panel according to some embodiments of the present disclosure.

[0045] Figure 22 This is an enlarged view of a second substrate in a display panel according to some embodiments of the present disclosure. Detailed Implementation

[0046] This disclosure will now be described in more detail with reference to the following embodiments. It should be noted that the following description of some embodiments presented herein is for illustrative and descriptive purposes only. It is not exhaustive or limited to the precise forms disclosed.

[0047] As miniature and micro-LED technology advances towards higher resolutions and higher pixel densities (PPI, pixels per inch), product substrates are transitioning from printed circuit boards to glass substrates. Because glass substrates cannot be drilled through and products are borderless, side wiring processes are required to route front signal lines to the back, where flexible printed circuits (FPCs) can be bonded to drive the display.

[0048] Currently, side-wiring processes are achieved either by sputtering combined with laser etching to form side circuits or by using 3D-printed silver wires. Sputtering and laser etching methods face several challenges. First, to reduce costs, products are shifting towards low-temperature polycrystalline silicon (LTPS) driver circuits on glass substrates to drive LEDs. However, the laser used in the etching process affects the thin-film transistor characteristics of the LTPS driver circuit, resulting in uneven LED brightness when the product is lit, which is an unresolved issue. Second, side-wiring processes have relatively low yields due to problems such as sputtered layer separation.

[0049] The method of 3D printing silver wires is limited by the precision requirements of the printing equipment, making it difficult to print irregular patterns. Furthermore, due to limitations in bonding processes and materials, it cannot accommodate high-precision, long FPC bonding. Therefore, to achieve a 3D printing method for side circuits, a bridging circuit needs to be attached to the back side to connect the 3D-printed wires to the FPC. During this process, since the 3D-printed silver wires need to crawl over the edges of the bridging circuit substrate, there is a risk of wire breakage. This necessitates printing an additional layer before the 3D-printed silver wires to mitigate the slope at the edges of the bridging circuit substrate. Because attaching the bridge and printing the additional layer before the silver wires requires curing at each step, the process is complex and prone to defects. The bridging substrate has a high coefficient of thermal expansion, leading to silver wire breakage during subsequent heating processes or reliability testing. Due to the coefficient of thermal expansion of the bridging substrate and the requirements of the touch panel, a 20μm thick substrate must be used, which is very expensive to produce. Additionally, its very thin thickness leads to high losses during manufacturing.

[0050] Figure 1 This is a schematic diagram showing the structure of the relevant display panel. (Refer to...) Figure 1The related display panel includes a first substrate SUB1 having multiple light-emitting elements (LEs) and multiple circuit signal lines (PDCs), a second substrate SUB2 located on the first substrate SUB1, and a flexible printed circuit (FPC) located on the side of the second substrate SUB2 away from the first substrate SUB1. The related display panel also includes one or more connecting lines CL that connect the multiple circuit signal lines (PDCs) and the flexible printed circuit (FPC) together. A first portion of the one or more connecting lines CL is located on the first substrate SUB1 and connected to the multiple circuit signal lines (PDCs). A second portion of the one or more connecting lines CL is attached to the lateral side of the first substrate SUB1 and the second substrate SUB2. A third portion of the one or more connecting lines CL is located on the side of the second substrate SUB2 and / or the flexible printed circuit (FPC) away from the first substrate SUB1.

[0051] Figure 2 This is a floor plan of the relevant display panel. Figure 3 This is a magnified view of a specific area of ​​the relevant display panel. (See reference) Figure 2 and Figure 3 The relevant display panel includes one or more fan-out lines (FOL) that are connected to one or more connection lines (CL) and to a flexible printed circuit (FPC).

[0052] Figure 4 These are microscopic images of the relevant display panel. In this display panel, the second substrate SUB2 is typically made of polyimide material. (See reference...) Figure 4 After the polyimide-based second substrate is formed, bubbles form, causing the protective layer covering the signal lines to crack. Figure 4 One or more cracked CRKs are shown in the relevant display panel.

[0053] Figure 5 These are microscopic images of the relevant display panel. (See reference) Figure 5 Sometimes, the polyimide-based second substrate in the display panel contains foreign matter FO, which can damage the display panel. Figure 5 The cracks are shown in the signal lines and protective layer.

[0054] Figure 6 These are microscopic images of the relevant display panel. (See reference) Figure 6 After the polyimide-based second substrate is formed and the pad layer printing is completed, the thickness of the pad layer affects the printing of one or more interconnects, resulting in uneven linewidth. In some cases, line breakage (LB) occurs in one or more interconnects.

[0055] Figure 7 These are scanning electron microscope images of the relevant display panel. Figure 7 This shows one or more cracks in the signal line CRK caused by bubbles or foreign objects.

[0056] Reference Figure 1 One or more connecting lines CL pass through a region having a first substrate SUB1 and enter a region having a second substrate SUB2. When transitioning from the region having the first substrate SUB1 to the region having the second substrate SUB2, the one or more connecting lines CL have a slope. The slope affects the shape of the one or more connecting lines CL and affects the line printing of the one or more connecting lines CL.

[0057] Figure 8 These are microscopic images of the relevant display panel. (See reference) Figure 8 One or more connecting lines CL have a first linewidth w1 in a region having a first substrate SUB1 and a second linewidth w2 in a region having a second substrate SUB2. The first linewidth w1 and the second linewidth w2 are different from each other. In one example, the first linewidth w1 is smaller than the second linewidth w2.

[0058] Figure 9 These are microscopic images of the relevant display panel. (See reference) Figure 9 Due to the slope of one or more connecting lines CL when transitioning from the region having the first substrate SUB1 to the region having the second substrate SUB2, one or more lines of the one or more connecting lines CL may break when transitioning from the region having the first substrate SUB1 to the region having the second substrate SUB2.

[0059] Therefore, this disclosure particularly provides a light-emitting substrate, a display device, and a method for manufacturing a light-emitting substrate, which substantially eliminates one or more problems caused by the limitations and disadvantages of the prior art. In one aspect, this disclosure provides a light-emitting substrate. In some embodiments, the light-emitting substrate includes: a first substrate having a plurality of light-emitting elements and a plurality of circuit signal lines; a flexible printed circuit and / or a second substrate, the flexible printed circuit and / or the second substrate being located on the first substrate; and one or more connecting lines and one or more signal lines, the connecting lines and one or more signal lines connecting the plurality of circuit signal lines and the flexible printed circuit together. Optionally, one or more signal lines are located on the side of the second substrate and / or the flexible printed circuit closer to the first substrate, and on the side of the first substrate closer to the second substrate and / or the flexible printed circuit. Optionally, one or more connecting lines are connected to one or more signal lines. Optionally, one or more signal lines are connected to the flexible printed circuit. Optionally, a first portion of one or more connecting lines is located on the first substrate. Optionally, a second portion of one or more connecting lines is attached to a lateral side of the first substrate. Optionally, a third portion of one or more connecting lines is located on the side of the first substrate closer to one or more signal lines, and on the side of one or more signal lines closer to the first substrate.

[0060] Figure 10This is a schematic diagram illustrating the structure of a display panel according to some embodiments of the present disclosure. Figure 11 This is a plan view of a display panel according to some embodiments of the present disclosure. Figure 12 This is an exploded view of a display panel according to some embodiments of this disclosure. (Refer to...) Figures 10 to 12 In some embodiments, the display panel includes a first substrate SUB1 having a plurality of light-emitting elements (LEs), a plurality of circuit signal lines (PDCs), and a bonding pad (CP). The bonding pad CP is connected to the plurality of circuit signal lines (PDCs). The plurality of circuit signal lines (PDCs) are connected to the plurality of light-emitting elements (LEs). In some embodiments, the display panel further includes: a second substrate SUB2 located on the first substrate SUB1; and a flexible printed circuit (FPC) located on the side of the second substrate SUB2 closest to the first substrate SUB1, and on the side of the first substrate SUB1 closest to the second substrate SUB2.

[0061] In some embodiments, the display panel further includes one or more connection lines CL and one or more signal lines SL that connect multiple circuit signal lines PDC and flexible printed circuit FPC together. In some embodiments, one or more connection lines CL are connected to bonding pads CP and to one or more signal lines SL; one or more signal lines SL are connected to one or more connection lines CL and to the flexible printed circuit FPC.

[0062] In some embodiments, one or more signal lines SL are located on the side of the second substrate SUB2 closest to the first substrate SUB1, and on the side of the first substrate SUB1 closest to the second substrate SUB2. In some embodiments, one or more signal lines SL are in direct contact with one or more connection lines CL.

[0063] In some embodiments, a first portion P1 of one or more connection lines CL is located on a first substrate SUB1 and connected to a bonding pad CP; a second portion P2 of one or more connection lines CL is attached to a lateral side of the first substrate SUB1; and a third portion P3 of one or more connection lines CL is located on the side of the first substrate SUB1 closest to one or more signal lines SL. Optionally, the second portion P2 and the third portion P3 of one or more connection lines CL are in direct contact with the first substrate SUB1.

[0064] In some embodiments, the display panel further includes a conductive adhesive layer (CAL). In some embodiments, one or more signal lines (SL) are connected to a flexible printed circuit (FPC) via the conductive adhesive layer (CAL).

[0065] In some embodiments, the display panel further includes an adhesive layer AL for attaching the second substrate SUB2 to the first substrate SUB1. Optionally, the adhesive layer AL is non-conductive.

[0066] In some embodiments, the display panel further includes a protective layer PL covering one or more interconnecting lines CL. The protective layer PL is made of an insulating material.

[0067] In some embodiments, the second substrate SUB2 is made of an inorganic insulating material. The inventors of this disclosure have discovered that by providing a second substrate SUB2 made of an inorganic insulating material, various problems associated with the relevant display panel (e.g., ...) can be avoided. Figures 4 to 9 As shown), in the relevant display panel, the second substrate SUB2 is made of an organic insulating material (e.g., polyimide). In a particular example, the second substrate SUB2 is made of glass.

[0068] In some embodiments, the thickness of the second substrate SUB2 ranges from 0.3 mm to 0.5 mm. In some embodiments, the ratio of the thickness of the second substrate SUB2 to the thickness of the first substrate SUB1 is in the range of 0.6 to 1.0, for example, 0.6 to 0.7, 0.7 to 0.8, 0.8 to 0.9, or 0.9 to 1.0. In a particular example, the thickness of the first substrate SUB1 is 0.5 mm, and the thickness of the second substrate SUB2 is 0.3 mm.

[0069] On the other hand, this disclosure provides a method for manufacturing a light-emitting substrate. In some embodiments, the method includes: providing a first substrate; forming one or more interconnect lines on the first substrate; providing a second substrate; forming one or more signal lines on the second substrate; bonding a flexible printed circuit to the second substrate; and attaching the second substrate to the first substrate, thereby connecting the one or more signal lines to the one or more interconnect lines.

[0070] In some embodiments, forming one or more interconnects on a first substrate includes printing a conductive material (e.g., silver paste) on the first substrate to form one or more interconnects on the first substrate.

[0071] In some embodiments, connecting one or more signal lines to one or more connection lines includes: attaching a second substrate to a first substrate to connect one or more signal lines to an uncured conductive material printed on the first substrate; and subsequently curing the conductive material to form one or more connection lines using the cured conductive material, and connecting one or more signal lines to one or more connection lines.

[0072] In some embodiments, attaching the second substrate to the first substrate includes forming an adhesive layer to attach the second substrate and / or one or more signal lines to the first substrate.

[0073] In some embodiments, bonding the flexible printed circuit to the second substrate includes forming a conductive adhesive layer to bond the flexible printed circuit to the second substrate.

[0074] In some embodiments, the method further includes forming a protective layer covering one or more connection lines.

[0075] The inventors of this disclosure have discovered several problems related to the relevant display panels. For example, the second substrate in the relevant display panel may be too fragile, making one or more interconnects and the protective layer easily damaged, which affects yield. In another example, the second substrate in the relevant display panel may be too thin, causing wrinkles and bubbles to form during the bonding process, which affects one or more interconnects and the protective layer. In yet another example, the second substrate in the relevant display panel may be too thin, causing thermal properties and the coefficient of thermal expansion to affect accuracy during the attachment of the second substrate to the first substrate. In yet another example, the second substrate in the relevant display panel may have strict requirements on the materials used to manufacture the second substrate, resulting in higher costs.

[0076] The inventors of this disclosure have discovered that the display panel of this disclosure overcomes several problems in related display panels. For example, this disclosure greatly simplifies the process of preparing the second substrate, shortens the production cycle, and reduces material costs. In manufacturing the second substrate in related display panels, the manufacturing process typically includes forming one or more signal lines on the second substrate, forming a protective layer covering the one or more signal lines, cutting, laser peeling, applying a thermosetting adhesive coating to the second substrate, applying a protective film, applying a carrier film, punching the film material, and storing it in a refrigerator. In contrast, the manufacturing method according to this disclosure includes providing a second substrate, forming one or more signal lines on the second substrate, forming a protective layer covering the one or more signal lines, cutting, and glass grinding. The manufacturing process of the second substrate according to this disclosure is greatly simplified.

[0077] In this disclosure, the manufacturing process for forming the display panel is also greatly simplified. When manufacturing a related display panel, the manufacturing process typically includes providing a first substrate, attaching a polyimide-based second substrate to the first substrate, degassing the polyimide-based second substrate, curing the polyimide-based second substrate, printing a pad layer, curing the pad layer, printing one or more interconnects, curing one or more interconnects, and bonding a flexible printed circuit to the second substrate. In contrast, the manufacturing process according to this disclosure includes providing a first substrate, printing one or more interconnects, providing a second substrate, bonding a flexible printed circuit to the second substrate, attaching the second substrate to the first substrate, and curing one or more interconnects.

[0078] The inventors of this disclosure have discovered that this disclosure significantly improves the alignment accuracy between the first substrate and the second substrate. In the manufacturing of the relevant display panel, the polyimide-based second substrate is flexible and has an alignment accuracy of ±40 μm. In this disclosure, both the first and second substrates are made of rigid materials, thereby allowing for an alignment accuracy of ±5 μm. This improved alignment accuracy enhances the ability of side wiring processes to produce finer lines.

[0079] During the manufacturing of the display panel, small air bubbles may remain after the protective film is applied to the second substrate. These bubbles are not easily eliminated during the degassing process, and they often enlarge during subsequent heating steps, leading to damage to the protective layer on the polyimide-based second substrate.

[0080] If foreign objects are introduced during the application of the protective film in the manufacturing of the display panel, these objects may damage one or more connecting lines and the protective layer. This type of defect can significantly impact the product's lifespan. Because the defect may not immediately cause direct line breakage, it is difficult to detect during the manufacturing process.

[0081] Figure 13 This is an enlarged view of a display panel according to some embodiments of the present disclosure. (Refer to...) Figure 13 Along a plane intersecting the first substrate SUB1, the second substrate SUB2, one or more signal lines SL, and one or more connection lines CL, the one or more signal lines and one or more connection lines are in contact with each other along a first distance d1. In some embodiments, the first distance d1 is greater than 50 μm to minimize the resistance between the one or more signal lines SL and the one or more connection lines CL (e.g., less than 1 Ω).

[0082] In some embodiments, the second distance d2 represents a safety distance for alignment accuracy between the second substrate SUB2 and the first substrate SUB1. The safety distance ensures that the second substrate SUB2 does not protrude beyond the edge of the first substrate SUB1, thereby maintaining the integrity of the seamless splicing.

[0083] Figure 14 This is an enlarged view of a first substrate in a display panel according to some embodiments of the present disclosure. (Refer to...) Figure 14 In some embodiments, the first substrate SUB1 includes a first surface S1 on which a third portion of one or more connecting lines CL are disposed, and a second surface S2 on which a second portion of one or more connecting lines CL are disposed. In some embodiments, the first substrate SUB1 includes a chamfered portion CMP located between the first surface S1 and the second surface S2, wherein the chamfered portion CMP has a chamfered edge. In some embodiments, reference is made to... Figure 13 and Figure 14Along a plane intersecting the first substrate SUB1, the second substrate SUB2, one or more signal lines SL, and one or more connection lines CL, the second distance d2 is the distance between the orthographic projection of the edge of the second substrate SUB2 onto the first surface S1 and the line between the first surface S1 and the chamfered portion CMP. In some embodiments, considering that the alignment accuracy between the first substrate SUB1 and the second substrate SUB2 is ±5μm, the second distance d2 is greater than 5μm.

[0084] In some embodiments, the alignment accuracy a1 between the first substrate SUB1 and the second substrate SUB2 is ±5 μm; the polishing accuracy a2 of the first substrate SUB1 is ±15 μm; and the polishing accuracy a3 of the second substrate SUB2 is ±15 μm. In some embodiments, the second distance d2 can be expressed as... In one example, d2 ≥ 21.8 μm.

[0085] In some embodiments, refer to Figure 13 and Figure 14 Along a plane intersecting the first substrate SUB1, the second substrate SUB2, one or more signal lines SL, and one or more connection lines CL, the third distance d3 is the distance between the line between the first surface S1 and the chamfered portion CMP and the orthographic projection of the second surface S2 onto the plane containing the first surface S1. In some embodiments, the third distance d3 is in the range of 10 μm to 50 μm, for example, 10 μm to 20 μm, 20 μm to 30 μm, 30 μm to 40 μm, or 40 μm to 50 μm. By setting the third distance d3, the strength and durability of the first substrate SUB1 can be enhanced, and the risk of breakage at the edges can be mitigated. This ensures that the chamfer not only protects the edges from damage but also maintains the integrity of one or more connection lines CL near the edges.

[0086] Reference Figure 13 In some embodiments, the protective layer PL includes a sealing portion SP that contacts the second substrate SUB2 and one or more connection lines CL to ensure complete sealing of the one or more connection lines CL. In some embodiments, the sealing portion SP is at least partially located on the lateral side of the second substrate SUB2.

[0087] As described above, in manufacturing the relevant display panel, a second substrate is first attached to a first substrate, and then one or more connection lines are printed on the second substrate using one or more terminal leads as a reference. In this disclosure, the second substrate is made of inorganic material instead of organic material, which significantly improves the alignment accuracy between the first substrate and the second substrate. Figure 15This illustration shows the connection between one or more connecting lines and one or more terminal leads on a second substrate in a display panel according to some embodiments of the present disclosure. In some embodiments, one or more terminal leads TL on the second substrate SUB2 are respectively connected to one or more signal lines on the second substrate SUB2. In the process of manufacturing the display panel of the present disclosure, in some embodiments, conductive material is first printed on a first substrate SUB1 to form one or more uncured connecting lines, and then the second substrate SUB2 is attached to the first substrate SUB1 by aligning one or more terminal leads TL with one or more uncured connecting lines, thereby connecting one or more terminal leads TL to one or more uncured connecting lines. Subsequently, one or more uncured connecting lines are cured to form one or more connecting lines CL. Compared with the process of manufacturing the relevant display panel, the one or more connecting lines CL according to the present disclosure do not have a slope transitioning from the area having the first substrate SUB1 to the area having the second substrate SUB2, thereby significantly reducing the occurrence of defects such as line breaks and line width inhomogeneity.

[0088] Figure 16 This is a plan view of a portion of a display panel according to some embodiments of the present disclosure. Figure 17 This is a cross-sectional view of a portion of a display panel according to some embodiments of the present disclosure. Figure 17 It is along Figure 16 Cross-sectional view of line A-A'. (Refer to...) Figure 16 and Figure 17 In some embodiments, the display panel includes a second substrate SUB2, one or more signal lines SL located on the second substrate SUB2, and a pad UNL located on the side of the one or more signal lines SL away from the second substrate SUB2. The pad UNL covers the one or more signal lines SL except for one or more terminal leads TL connected to one or more connection lines. Optionally, each terminal lead in the one or more terminal leads TL is part of a corresponding signal line in the one or more signal lines SL.

[0089] In some embodiments, the length of each terminal lead in one or more terminal leads TL is greater than 60 μm, for example greater than 70 μm, greater than 80 μm, greater than 90 μm, or greater than 100 μm.

[0090] In some embodiments, the display panel includes a plurality of slits SLT; the underlay UNL includes a plurality of baffles BR; the plurality of slits SLT and the plurality of baffles BR are alternately arranged. Each slit in the plurality of slits SLT exposes a corresponding terminal lead in one or more terminal leads TL. The plurality of baffles BR are used to prevent one or more uncured wires from deforming and short-circuiting under pressure before the one or more uncured wires are cured to form one or more connections. In some embodiments, along the direction spanning the plurality of baffles BR and the plurality of slits SLT, the width w of each baffle in the plurality of baffles BR is greater than 15 μm, for example, greater than 20 μm, greater than 25 μm, greater than 30 μm, or greater than 35 μm.

[0091] In some embodiments, one or more signal lines SL further include one or more bonding leads BL. Each bonding lead in the one or more bonding leads BL is located at the opposite end of a corresponding signal line in the one or more signal lines SL, relative to a corresponding terminal lead in the one or more terminal leads TL. The one or more bonding leads BL are configured to bond to a flexible printed circuit. In some embodiments, the orthographic projection of the pad UNL on the substrate does not overlap with the orthographic projection of the one or more bonding leads on the substrate.

[0092] Figure 18 This is a schematic diagram illustrating the structure of a display panel according to some embodiments of the present disclosure. (Refer to...) Figure 18 In some embodiments, the display panel includes a first substrate SUB1 having a plurality of light-emitting elements (LEs), a plurality of circuit signal lines (PDCs), and a bonding pad (CP). The bonding pad CP is connected to the plurality of circuit signal lines (PDCs). The plurality of circuit signal lines (PDCs) are connected to the plurality of light-emitting elements (LEs). In some embodiments, the display panel further includes a flexible printed circuit (FPC) located on the first substrate SUB1.

[0093] In some embodiments, the display panel further includes one or more connection lines CL connecting a plurality of circuit signal lines PDC and a flexible printed circuit FPC, and one or more signal lines SL. In some embodiments, the one or more connection lines CL are connected to a bonding pad CP and to one or more signal lines SL; the one or more signal lines SL are connected to the flexible printed circuit FPC.

[0094] In some embodiments, one or more signal lines SL are located on the side of the flexible printed circuit FPC closest to the first substrate SUB1, and on the side of the first substrate SUB1 closest to the flexible printed circuit FPC. In some embodiments, one or more signal lines SL are in direct contact with one or more connection lines CL.

[0095] In some embodiments, a first portion P1 of one or more connection lines CL is located on a first substrate SUB1 and connected to a bonding pad CP; a second portion P2 of one or more connection lines CL is attached to a lateral side of the first substrate SUB1; and a third portion P3 of one or more connection lines CL is located on the side of the first substrate SUB1 closest to one or more signal lines SL. Optionally, the second portion P2 and the third portion P3 of one or more connection lines CL are in direct contact with the first substrate SUB1.

[0096] In some embodiments, the display panel further includes an adhesive layer AL for attaching the flexible printed circuit (FPC) to the first substrate SUB1. Optionally, the adhesive layer AL is non-conductive.

[0097] In some embodiments, the display panel further includes a protective layer PL covering one or more interconnecting lines CL. The protective layer PL is made of an insulating material.

[0098] On the other hand, this disclosure provides a method for manufacturing a light-emitting substrate. In some embodiments, the method includes: providing a first substrate; forming one or more interconnecting lines on the first substrate; providing a flexible printed circuit; forming one or more signal lines on the flexible printed circuit; and attaching the flexible printed circuit to the first substrate, thereby connecting the one or more signal lines to the one or more interconnecting lines.

[0099] In some embodiments, forming one or more interconnects on a first substrate includes printing a conductive material (e.g., silver paste) on the first substrate to form one or more interconnects on the first substrate.

[0100] In some embodiments, connecting one or more signal lines to one or more connection lines includes: attaching a flexible printed circuit to a first substrate to connect one or more signal lines to an uncured conductive material printed on the first substrate; and subsequently curing the conductive material to form one or more connection lines using the cured conductive material, and connecting the one or more signal lines to the one or more connection lines.

[0101] In some embodiments, attaching a flexible printed circuit to a first substrate includes forming an adhesive layer to attach the flexible printed circuit and / or one or more signal lines to the first substrate.

[0102] In some embodiments, the method further includes forming a protective layer covering one or more connection lines.

[0103] Figure 19 This is a schematic diagram illustrating the structure of a display panel according to some embodiments of the present disclosure. (Refer to...) Figure 19In some embodiments, the display panel includes a first substrate SUB1 having a plurality of light-emitting elements (LEs), a plurality of circuit signal lines (PDCs), and a bonding pad (CP). The bonding pad CP is connected to the plurality of circuit signal lines (PDCs). The plurality of circuit signal lines (PDCs) are connected to the plurality of light-emitting elements (LEs). In some embodiments, the display panel further includes: a second substrate SUB2 located on the first substrate SUB1; and a flexible printed circuit (FPC) located on the side of the second substrate SUB2 closest to the first substrate SUB1, and on the side of the first substrate SUB1 closest to the second substrate SUB2.

[0104] In some embodiments, the display panel further includes one or more connection lines CL and one or more signal lines SL that connect multiple circuit signal lines PDC and flexible printed circuit FPC together. In some embodiments, one or more connection lines CL are connected to bonding pads CP and to one or more signal lines SL; one or more signal lines SL are connected to one or more connection lines CL and to the flexible printed circuit FPC.

[0105] In some embodiments, one or more signal lines SL are located on the side of the second substrate SUB2 closest to the first substrate SUB1, and on the side of the first substrate SUB1 closest to the second substrate SUB2. In some embodiments, the display panel further includes a first conductive adhesive layer CAL1. In some embodiments, one or more signal lines SL are connected to one or more connecting lines CL through the first conductive adhesive layer CAL1.

[0106] In some embodiments, a first portion P1 of one or more connection lines CL is located on a first substrate SUB1 and connected to a bonding pad CP; a second portion P2 of one or more connection lines CL is attached to a lateral side of the first substrate SUB1; and a third portion P3 of one or more connection lines CL is located on the side of the first substrate SUB1 closest to one or more signal lines SL. Optionally, the second portion P2 and the third portion P3 of one or more connection lines CL are in direct contact with the first substrate SUB1.

[0107] In some embodiments, the display panel further includes a second conductive adhesive layer CAL2. In some embodiments, one or more signal lines SL are connected to the flexible printed circuit (FPC) via the second conductive adhesive layer CAL2.

[0108] In some embodiments, the display panel further includes an adhesive layer AL for attaching the second substrate SUB2 to the first substrate SUB1. Optionally, the adhesive layer AL is non-conductive.

[0109] In some embodiments, the display panel further includes a protective layer PL covering one or more interconnecting lines CL. The protective layer PL is made of an insulating material.

[0110] In some embodiments, the second substrate SUB2 is made of an inorganic insulating material. The inventors of this disclosure have discovered that by providing a second substrate SUB2 made of an inorganic insulating material, various problems associated with the relevant display panel (e.g., ...) can be avoided. Figures 4 to 9 As shown), in the relevant display panel, the second substrate SUB2 is made of an organic insulating material (e.g., polyimide). In a particular example, the second substrate SUB2 is made of glass.

[0111] In some embodiments, the thickness of the second substrate SUB2 ranges from 0.3 mm to 0.5 mm. In some embodiments, the ratio of the thickness of the second substrate SUB2 to the thickness of the first substrate SUB1 is in the range of 0.6 to 1.0, for example, 0.6 to 0.7, 0.7 to 0.8, 0.8 to 0.9, or 0.9 to 1.0. In a particular example, the thickness of the first substrate SUB1 is 0.5 mm, and the thickness of the second substrate SUB2 is 0.3 mm.

[0112] On the other hand, this disclosure provides a method for manufacturing a light-emitting substrate. In some embodiments, the method includes: providing a first substrate; forming one or more interconnect lines on the first substrate; providing a second substrate; forming one or more signal lines on the second substrate; bonding a flexible printed circuit to the second substrate; and attaching the second substrate to the first substrate, thereby connecting the one or more signal lines to the one or more interconnect lines.

[0113] In some embodiments, forming one or more interconnects on a first substrate includes printing a conductive material (e.g., silver paste) on the first substrate to form one or more interconnects on the first substrate.

[0114] In some embodiments, connecting one or more signal lines to one or more connection lines includes: forming a first conductive adhesive layer to connect the one or more signal lines to the one or more connection lines. Optionally, before connecting the one or more signal lines to the one or more connection lines, the method further includes: printing a conductive material (e.g., silver paste) on a first substrate, and curing the conductive material to form the one or more connection lines. The inventors of this disclosure have found that by first curing the conductive material to form the one or more connection lines, the one or more connection lines are less prone to deformation.

[0115] In some embodiments, attaching the second substrate to the first substrate includes forming an adhesive layer to attach the second substrate and / or one or more signal lines to the first substrate.

[0116] In some embodiments, bonding the flexible printed circuit to the second substrate includes forming a second conductive adhesive layer to bond the flexible printed circuit to the second substrate.

[0117] In some embodiments, the method further includes forming a protective layer covering one or more connection lines.

[0118] The inventors of this disclosure have discovered several problems related to the relevant display panels. For example, the second substrate in the relevant display panel may be too fragile, making one or more interconnects and the protective layer easily damaged, which affects yield. In another example, the second substrate in the relevant display panel may be too thin, causing wrinkles and bubbles to form during the bonding process, which affects one or more interconnects and the protective layer. In yet another example, the second substrate in the relevant display panel may be too thin, causing thermal properties and the coefficient of thermal expansion to affect accuracy during the attachment of the second substrate to the first substrate. In yet another example, the second substrate in the relevant display panel may have strict requirements on the materials used to manufacture the second substrate, resulting in higher costs.

[0119] The inventors of this disclosure have discovered that the display panel of this disclosure overcomes several problems in related display panels. For example, this disclosure greatly simplifies the process of preparing the second substrate, shortens the production cycle, and reduces material costs. In manufacturing the second substrate in related display panels, the manufacturing process typically includes forming one or more signal lines on the second substrate, forming a protective layer covering the one or more signal lines, cutting, laser peeling, applying a thermosetting adhesive coating to the second substrate, applying a protective film, applying a carrier film, punching the film material, and storing it in a refrigerator. In contrast, the manufacturing method according to this disclosure includes providing a second substrate, forming one or more signal lines on the second substrate, forming a protective layer covering the one or more signal lines, cutting, and glass grinding. The manufacturing process of the second substrate according to this disclosure is greatly simplified.

[0120] In this disclosure, the manufacturing process for forming the display panel is also greatly simplified. When manufacturing a related display panel, the manufacturing process typically includes providing a first substrate, attaching a polyimide-based second substrate to the first substrate, degassing the polyimide-based second substrate, curing the polyimide-based second substrate, printing a pad layer, curing the pad layer, printing one or more interconnects, curing one or more interconnects, and bonding a flexible printed circuit to the second substrate. In contrast, the manufacturing process according to this disclosure includes providing a first substrate, printing one or more interconnects, providing a second substrate, bonding a flexible printed circuit to the second substrate, attaching the second substrate to the first substrate, and curing one or more interconnects.

[0121] The inventors of this disclosure have discovered that this disclosure significantly improves the alignment accuracy between the first substrate and the second substrate. In the manufacturing of the relevant display panel, the polyimide-based second substrate is flexible and has an alignment accuracy of ±40 μm. In this disclosure, both the first and second substrates are made of rigid materials, thereby allowing for an alignment accuracy of ±5 μm. This improved alignment accuracy enhances the ability of side wiring processes to produce finer lines.

[0122] During the manufacturing of the display panel, small air bubbles may remain after the protective film is applied to the second substrate. These bubbles are not easily eliminated during the degassing process, and they often enlarge during subsequent heating steps, leading to damage to the protective layer on the polyimide-based second substrate.

[0123] If foreign objects are introduced during the application of the protective film in the manufacturing of the display panel, these objects may damage one or more connecting lines and the protective layer. This type of defect can significantly impact the product's lifespan. Because the defect may not immediately cause direct line breakage, it is difficult to detect during the manufacturing process.

[0124] Figure 20 This is a schematic diagram illustrating the structure of a display panel according to some embodiments of the present disclosure. (Refer to...) Figure 20 In some embodiments, the display panel includes a first substrate SUB1 having a plurality of light-emitting elements (LEs), a plurality of circuit signal lines (PDCs), and a bonding pad (CP). The bonding pad CP is connected to the plurality of circuit signal lines (PDCs). The plurality of circuit signal lines (PDCs) are connected to the plurality of light-emitting elements (LEs). In some embodiments, the display panel further includes a flexible printed circuit (FPC) located on the first substrate SUB1.

[0125] In some embodiments, the display panel further includes one or more connection lines CL and one or more signal lines SL that connect multiple circuit signal lines PDC and flexible printed circuit FPC together. In some embodiments, one or more connection lines CL are connected to bonding pads CP and to one or more signal lines SL; one or more signal lines SL are connected to one or more connection lines CL and to the flexible printed circuit FPC.

[0126] In some embodiments, one or more signal lines SL are located on the side of the flexible printed circuit (FPC) closest to the first substrate SUB1, and on the side of the first substrate SUB1 closest to the flexible printed circuit (FPC). In some embodiments, the display panel further includes a first conductive adhesive layer CAL1. In some embodiments, one or more signal lines SL are connected to one or more connection lines CL via the first conductive adhesive layer CAL1.

[0127] In some embodiments, a first portion P1 of one or more connection lines CL is located on a first substrate SUB1 and connected to a bonding pad CP; a second portion P2 of one or more connection lines CL is attached to a lateral side of the first substrate SUB1; and a third portion P3 of one or more connection lines CL is located on the side of the first substrate SUB1 closest to one or more signal lines SL. Optionally, the second portion P2 and the third portion P3 of one or more connection lines CL are in direct contact with the first substrate SUB1.

[0128] In some embodiments, the display panel further includes an adhesive layer AL for attaching the flexible printed circuit (FPC) to the first substrate SUB1. Optionally, the adhesive layer AL is non-conductive.

[0129] In some embodiments, the display panel further includes a protective layer PL covering one or more interconnecting lines CL. The protective layer PL is made of an insulating material.

[0130] On the other hand, this disclosure provides a method for manufacturing a light-emitting substrate. In some embodiments, the method includes: providing a first substrate; forming one or more interconnecting lines on the first substrate; providing a flexible printed circuit; forming one or more signal lines on the flexible printed circuit; and attaching the flexible printed circuit to the first substrate, thereby connecting the one or more signal lines to the one or more interconnecting lines.

[0131] In some embodiments, forming one or more interconnects on a first substrate includes printing a conductive material (e.g., silver paste) on the first substrate to form one or more interconnects on the first substrate.

[0132] In some embodiments, connecting one or more signal lines to one or more connection lines includes: forming a first conductive adhesive layer to connect the one or more signal lines to the one or more connection lines. Optionally, before connecting the one or more signal lines to the one or more connection lines, the method further includes: printing a conductive material (e.g., silver paste) on a first substrate and curing the conductive material to form the one or more connection lines.

[0133] In some embodiments, attaching a flexible printed circuit to a first substrate includes forming an adhesive layer to attach the flexible printed circuit and / or one or more signal lines to the first substrate.

[0134] In some embodiments, the method further includes forming a protective layer covering one or more connection lines.

[0135] Figure 21 This is a schematic diagram illustrating the structure of a display panel according to some embodiments of the present disclosure. (Refer to...) Figure 21In some embodiments, the display panel includes a first substrate SUB1 having a plurality of light-emitting elements (LEs), a plurality of circuit signal lines (PDCs), and a bonding pad (CP). The bonding pad (CP) is connected to the plurality of circuit signal lines (PDCs). The plurality of circuit signal lines (PDCs) are connected to the plurality of light-emitting elements (LEs). In some embodiments, the display panel further includes a second substrate SUB2 located on the first substrate SUB1, and a flexible printed circuit (FPC) located on the side of the second substrate SUB2 away from the first substrate SUB1.

[0136] In some embodiments, the display panel further includes one or more connection lines CL and one or more signal lines SL that connect multiple circuit signal lines PDC and flexible printed circuit FPC together. In some embodiments, one or more connection lines CL are connected to bonding pads CP and to one or more signal lines SL; one or more signal lines SL are connected to one or more connection lines CL and to the flexible printed circuit FPC.

[0137] In some embodiments, one or more signal lines SL are located on the side of the second substrate SUB2 away from the first substrate SUB1. In some embodiments, one or more signal lines SL are in direct contact with one or more connection lines CL.

[0138] In some embodiments, a first portion P1 of one or more connecting lines CL is located on a first substrate SUB1 and connected to a bonding pad CP; a second portion P2 of one or more connecting lines CL is attached to a lateral side of the first substrate SUB1; a third portion P3 of one or more connecting lines CL is attached to a lateral side of a second substrate SUB2; and a fourth portion P4 of one or more connecting lines CL is located on the side of one or more signal lines SL away from the second substrate SUB2. Optionally, the second portion P2 is in direct contact with the first substrate SUB1. Optionally, the third portion P3 is in direct contact with the second substrate SUB2.

[0139] In some embodiments, the display panel further includes a conductive adhesive layer (CAL). In some embodiments, one or more signal lines (SL) are connected to a flexible printed circuit (FPC) via the conductive adhesive layer (CAL). Optionally, the flexible printed circuit (FPC) is located on the side of the conductive adhesive layer (CAL) away from the one or more signal lines (SL).

[0140] In some embodiments, the display panel further includes an adhesive layer AL for attaching the second substrate SUB2 to the first substrate SUB1. Optionally, the adhesive layer AL is non-conductive.

[0141] In some embodiments, the display panel further includes a protective layer PL covering one or more interconnecting lines CL. The protective layer PL is made of an insulating material.

[0142] Figure 22This is an enlarged view of a second substrate in a display panel according to some embodiments of the present disclosure. (Refer to...) Figure 22 In some embodiments, the second substrate SUB2 includes a first surface S1 on which one or more signal lines and one or more connection lines CL are placed, and a second surface S2 on which one or more connection lines CL are placed. In some embodiments, the second substrate SUB2 includes a chamfered portion CMP located between the first surface S1 and the second surface S2, wherein the chamfered portion CMP has a chamfered edge. In some embodiments, the first substrate SUB1 includes a third surface S3 on which one or more connection lines CL are placed. In some embodiments, the second surface S2 and the third surface S3 are substantially (e.g., at least 80%, at least 85%, at least 90%, at least 95%, at least 99%, or 100%) flat. The inventors of this disclosure have found that by making the second surface S2 and the third surface S3 substantially flat, the one or more connection lines CL according to this disclosure do not have a slope transitioning from the region having the first substrate SUB1 to the region having the second substrate SUB2, significantly reducing the occurrence of defects such as line breaks and line width inhomogeneity.

[0143] In some embodiments, the second substrate SUB2 is made of an inorganic insulating material. The inventors of this disclosure have discovered that by providing a second substrate SUB2 made of an inorganic insulating material, various problems associated with the relevant display panel (e.g., ...) can be avoided. Figures 4 to 9 As shown), in the relevant display panel, the second substrate SUB2 is made of an organic insulating material (e.g., polyimide). In a particular example, the second substrate SUB2 is made of glass.

[0144] In some embodiments, the thickness of the second substrate SUB2 ranges from 0.3 mm to 0.5 mm. In some embodiments, the ratio of the thickness of the second substrate SUB2 to the thickness of the first substrate SUB1 is in the range of 0.6 to 1.0, for example, 0.6 to 0.7, 0.7 to 0.8, 0.8 to 0.9, or 0.9 to 1.0. In a particular example, the thickness of the first substrate SUB1 is 0.5 mm, and the thickness of the second substrate SUB2 is 0.3 mm.

[0145] On the other hand, this disclosure provides a method for manufacturing a light-emitting substrate. In some embodiments, the method includes: providing a first substrate; providing a second substrate; attaching the second substrate to the first substrate; grinding the first substrate and the second substrate such that the surfaces of the lateral sides of the first substrate and the second substrate are substantially flat; forming one or more signal lines on the second substrate; forming one or more interconnecting lines on the first substrate and the second substrate, the one or more interconnecting lines being connected to the one or more signal lines; and bonding a flexible printed circuit to the second substrate.

[0146] In some embodiments, forming one or more interconnect lines on a first substrate and a second substrate includes: printing a conductive material (e.g., silver paste) on the first substrate to form one or more interconnect lines on the first substrate and the second substrate.

[0147] In some embodiments, forming one or more interconnects includes: forming a first portion P1 of one or more interconnects CL located on a first substrate SUB1 and connected to a bonding pad CP; forming a second portion P2 of one or more interconnects CL attached to a lateral side of the first substrate SUB1; forming a third portion P3 of one or more interconnects CL attached to a lateral side of a second substrate SUB2; and forming a fourth portion P4 of one or more interconnects CL located on a side of one or more signal lines SL away from the second substrate SUB2. Optionally, the second portion P2 is in direct contact with the first substrate SUB1. Optionally, the third portion P3 is in direct contact with the second substrate SUB2.

[0148] In some embodiments, the method further includes attaching a second substrate to a first substrate. In some embodiments, attaching the second substrate to the first substrate includes forming an adhesive layer to attach the second substrate to the first substrate.

[0149] In some embodiments, bonding the flexible printed circuit to the second substrate includes forming a conductive adhesive layer to bond the flexible printed circuit to the second substrate.

[0150] In some embodiments, the method further includes forming a protective layer covering one or more connection lines.

[0151] The inventors of this disclosure have discovered several problems related to the relevant display panels. For example, the second substrate in the relevant display panel may be too fragile, making one or more interconnects and the protective layer easily damaged, which affects yield. In another example, the second substrate in the relevant display panel may be too thin, causing wrinkles and bubbles to form during the bonding process, which affects one or more interconnects and the protective layer. In yet another example, the second substrate in the relevant display panel may be too thin, causing thermal properties and the coefficient of thermal expansion to affect accuracy during the attachment of the second substrate to the first substrate. In yet another example, the second substrate in the relevant display panel may have strict requirements on the materials used to manufacture the second substrate, resulting in higher costs.

[0152] The inventors of this disclosure have discovered that the display panel of this disclosure overcomes several problems in related display panels. For example, this disclosure greatly simplifies the process of preparing the second substrate, shortens the production cycle, and reduces material costs. In manufacturing the second substrate in related display panels, the manufacturing process typically includes forming one or more signal lines on the second substrate, forming a protective layer covering the one or more signal lines, cutting, laser peeling, applying a thermosetting adhesive coating to the second substrate, applying a protective film, applying a carrier film, punching the film material, and storing it in a refrigerator. In contrast, the manufacturing method according to this disclosure includes providing a second substrate, forming one or more signal lines on the second substrate, forming a protective layer covering the one or more signal lines, cutting, and glass grinding. The manufacturing process of the second substrate according to this disclosure is greatly simplified.

[0153] In this disclosure, the manufacturing process for forming the display panel is also greatly simplified. When manufacturing a related display panel, the manufacturing process typically includes providing a first substrate, attaching a polyimide-based second substrate to the first substrate, degassing the polyimide-based second substrate, curing the polyimide-based second substrate, printing a pad layer, curing the pad layer, printing one or more interconnects, curing one or more interconnects, and bonding a flexible printed circuit to the second substrate. In contrast, the manufacturing process according to this disclosure includes providing a first substrate, providing a second substrate, printing and curing one or more interconnects, bonding a flexible printed circuit to the second substrate, and attaching the second substrate to the first substrate.

[0154] The inventors of this disclosure have discovered that this disclosure significantly improves the alignment accuracy between the first substrate and the second substrate. In the manufacturing of the relevant display panel, the polyimide-based second substrate is flexible and has an alignment accuracy of ±40 μm. In this disclosure, both the first and second substrates are made of rigid materials, thereby allowing for an alignment accuracy of ±5 μm. This improved alignment accuracy enhances the ability of side wiring processes to produce finer lines.

[0155] During the manufacturing of the display panel, small air bubbles may remain after the protective film is applied to the second substrate. These bubbles are not easily eliminated during the degassing process, and they often enlarge during subsequent heating steps, leading to damage to the protective layer on the polyimide-based second substrate.

[0156] If foreign objects are introduced during the application of the protective film in the manufacturing of the display panel, these objects may damage one or more connecting lines and the protective layer. This type of defect can significantly impact the product's lifespan. Because the defect may not immediately cause direct line breakage, it is difficult to detect during the manufacturing process.

[0157] On the other hand, this disclosure provides a display device including a display panel manufactured as described herein or according to the methods described herein, and one or more integrated circuits connected to the display panel. Examples of suitable display devices include, but are not limited to, electronic paper, mobile phones, tablet computers, televisions, monitors, laptop computers, digital photo albums, GPS, etc. Optionally, the display device is an organic light-emitting diode (OLED) display device. Optionally, the display device is a miniature OLED display device. Optionally, the display device is a miniature OLED display device. Optionally, the display device is a quantum dot display device.

[0158] On the other hand, this disclosure provides a method for manufacturing a light-emitting substrate. In some embodiments, the method includes: providing a first substrate having a plurality of light-emitting elements and a plurality of circuit signal lines; attaching a flexible printed circuit and / or a second substrate to the first substrate; and forming one or more connecting lines and one or more signal lines connecting the plurality of circuit signal lines and the flexible printed circuit together. Optionally, one or more signal lines are formed on a side of the second substrate and / or the flexible printed circuit near the first substrate and on a side of the first substrate near the second substrate and / or the flexible printed circuit. Optionally, one or more connecting lines are connected to one or more signal lines. Optionally, one or more signal lines are connected to the flexible printed circuit. Optionally, a first portion of one or more connecting lines is located on the first substrate. Optionally, a second portion of one or more connecting lines CL is attached to a lateral side of the first substrate. Optionally, a third portion of one or more connecting lines is located on a side of the first substrate near the one or more signal lines and on a side of the one or more signal lines near the first substrate.

[0159] For illustrative and descriptive purposes, the foregoing description of embodiments of the invention has been provided. It is not exhaustive, nor is it intended to limit the invention to the precise forms or exemplary embodiments disclosed. Therefore, the foregoing description should be considered illustrative rather than restrictive. Clearly, many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to explain the principles of the invention and its best mode of practical application, thereby enabling those skilled in the art to understand the various embodiments of the invention and the various modifications suitable for the particular use or implementation contemplated. The scope of the invention is intended to be defined by the appended claims and their equivalents, wherein, unless otherwise stated, all terms are to be interpreted in their broadest reasonable sense. Therefore, the terms “the invention,” “the present invention,” etc., do not necessarily limit the scope of the claims to specific examples, and references to exemplary embodiments of the invention do not imply limitation of the invention, nor should such limitation be inferred. The invention is defined only by the spirit and scope of the appended claims. Furthermore, these claims may involve the use of “first,” “second,” etc., followed by nouns or elements. These terms should be understood as nomenclature and should not be construed as limiting the number of elements modified by these nomenclatures unless a specific number has been given. Any advantages and benefits described may not apply to all embodiments of the invention. It should be understood that changes to the described embodiments can be made by those skilled in the art without departing from the scope of the invention as defined by the appended claims. Furthermore, the elements and components in this disclosure are not intended for public distribution, whether or not they are expressly recited in the appended claims.

Claims

1. A light-emitting substrate, comprising: The first substrate has multiple light-emitting elements and multiple circuit signal lines; A flexible printed circuit and / or a second substrate, wherein the flexible printed circuit and / or the second substrate are located on the first substrate; as well as One or more connecting lines and one or more signal lines, wherein the one or more connecting lines and the one or more signal lines electrically connect the plurality of circuit signal lines and the flexible printed circuit together; Wherein, one or more signal lines are located on the side of the second substrate and / or the flexible printed circuit closer to the first substrate, and on the side of the first substrate closer to the second substrate and / or the flexible printed circuit. The one or more connecting lines are connected to the one or more signal lines; The one or more signal lines are connected to the flexible printed circuit; The first portion of the one or more connecting lines is located on the first substrate; The second portion of the one or more connecting lines is attached to the lateral side of the first substrate; and The third portion of the one or more connecting lines is located on the side of the first substrate closer to the one or more signal lines, and on the side of the one or more signal lines closer to the first substrate.

2. The light-emitting substrate according to claim 1, comprising both the second substrate and the flexible printed circuit; in, The second substrate is located on the first substrate; The flexible printed circuit is located on the side of the second substrate closer to the first substrate, and on the side of the first substrate closer to the second substrate. The one or more signal lines are located on the side of the second substrate closer to the first substrate, and on the side of the first substrate closer to the second substrate; as well as The one or more signal lines are attached to the second substrate.

3. The light-emitting substrate according to claim 2, wherein, The second substrate is made of an inorganic insulating material; and The ratio of the thickness of the second substrate to the thickness of the first substrate is in the range of 0.6 to 1.

0.

4. The light-emitting substrate according to claim 2, wherein, The thickness of the second substrate is in the range of 0.3 mm to 0.5 mm.

5. The light-emitting substrate according to claim 2, wherein, Along a plane intersecting the first substrate, the second substrate, the one or more signal lines, and the one or more connecting lines, the one or more signal lines and the one or more connecting lines are in contact with each other at a first distance; The first substrate includes a first surface and a second surface, the third portion of the one or more connecting lines is placed on the first surface, and the second portion of the one or more connecting lines is placed on the second surface; The first substrate includes a chamfered portion located between the first surface and the second surface, the chamfered portion having a chamfered edge; Along a plane intersecting the first substrate, the second substrate, the one or more signal lines, and the one or more connection lines, a second distance between the orthographic projection of the edge of the second substrate onto the first surface and the line between the first surface and the chamfered portion is less than the first distance; and Along a plane intersecting the first substrate, the second substrate, the one or more signal lines, and the one or more connection lines, a third distance between the line between the first surface and the chamfered portion and the orthographic projection of the second surface onto the plane containing the first surface is greater than the second distance and less than the first distance.

6. The light-emitting substrate according to claim 5, wherein, The alignment accuracy a1 between the first substrate and the second substrate is ±5μm; The polishing precision a2 of the first substrate is ±15μm; The polishing precision a3 of the second substrate is ±15μm; and The 7. The light-emitting substrate according to claim 2 further includes a second conductive adhesive layer; in, The one or more signal lines are connected to the flexible printed circuit through the second conductive adhesive layer.

8. The light-emitting substrate according to claim 2, further comprising an adhesive layer for attaching the second substrate to the first substrate.

9. The light-emitting substrate according to claim 2, further comprising a pad layer located on the side of the one or more signal lines away from the second substrate; in, The padding partially covers the one or more signal lines; The light-emitting substrate includes multiple slits; The cushion layer includes multiple retaining walls; The plurality of slits and the plurality of retaining walls are alternately arranged; The one or more signal lines include one or more terminal leads connected to the one or more connection lines; and Each of the plurality of slits exposes a corresponding terminal lead in one or more of the terminal leads.

10. The light-emitting substrate according to claim 9, wherein, Along the direction spanning the plurality of retaining walls and the plurality of slits, the width of each of the plurality of retaining walls is greater than 15 μm.

11. The light-emitting substrate according to claim 9, wherein, The one or more signal lines include one or more bonding leads configured to be bonded to the flexible printed circuit; Each of the one or more bonding leads is located at the opposite end of the corresponding signal line among the one or more terminal leads; as well as The orthographic projection of the pad layer on the substrate does not overlap with the orthographic projection of the one or more bonding leads on the substrate.

12. The light-emitting substrate according to claim 1, comprising: The flexible printed circuit is located on the first substrate; as well as An adhesive layer that attaches the flexible printed circuit to the first substrate; The one or more signal lines are located on the side of the flexible printed circuit closer to the first substrate, and on the side of the first substrate closer to the flexible printed circuit.

13. The light-emitting substrate according to any one of claims 1 to 12, wherein, The one or more signal lines are in direct contact with the one or more connecting lines.

14. The light-emitting substrate according to any one of claims 1 to 12, further comprising a first conductive adhesive layer; in, The one or more signal lines are connected to the one or more connecting lines through the first conductive adhesive layer.

15. The light-emitting substrate according to any one of claims 1 to 14, wherein, The second and third portions of the one or more connecting lines are in direct contact with the first substrate.

16. The light-emitting substrate according to any one of claims 1 to 15, further comprising a protective layer covering the one or more connecting lines; in, The protective layer includes a sealing portion that contacts the second substrate and the one or more connecting lines; and The sealing portion is located at least partially on the lateral side of the second substrate.

17. A light-emitting substrate, comprising: The first substrate has multiple light-emitting elements and multiple circuit signal lines; The second substrate is located on the first substrate; A flexible printed circuit is located on the side of the second substrate away from the first substrate; One or more connecting lines and one or more signal lines, the one or more connecting lines and the one or more signal lines connecting the plurality of circuit signal lines and the flexible printed circuit together; Wherein, the one or more connecting lines are connected to the one or more signal lines; The one or more signal lines are connected to the flexible printed circuit; The one or more signal lines are located on the side of the second substrate away from the first substrate; The first portion of the one or more connecting lines is located on the first substrate; The second portion of the one or more connecting lines is attached to the lateral side of the first substrate; A third portion of the one or more connecting lines is attached to a lateral side of the second substrate; and The fourth portion of the one or more connecting lines is located on the side of the one or more signal lines away from the second substrate.

18. The light-emitting substrate according to claim 17, wherein, The second substrate includes a first surface and a second surface, the fourth portion of the one or more signal lines and the one or more connecting lines is placed on the first surface, and the third portion of the one or more connecting lines is placed on the second surface; The second substrate includes a chamfered portion located between the first surface and the second surface, the chamfered portion having a chamfered edge; The first substrate includes a third surface, and the second portion of the one or more connecting lines is disposed on the third surface; and The second and third surfaces are substantially flat.

19. A display device comprising a light-emitting substrate according to any one of claims 1 to 18 and one or more integrated circuits connected to the light-emitting substrate.

20. A method for manufacturing a light-emitting substrate, comprising: A first substrate having multiple light-emitting elements and multiple circuit signal lines is provided; Attach the flexible printed circuit and / or the second substrate to the first substrate; as well as Form one or more connection lines and one or more signal lines that connect the plurality of circuit signal lines and the flexible printed circuit together; Wherein, one or more signal lines are formed on the side of the second substrate and / or the flexible printed circuit near the first substrate and on the side of the first substrate near the second substrate and / or the flexible printed circuit. The one or more connecting lines are connected to the one or more signal lines; The one or more signal lines are connected to the flexible printed circuit; The first portion of the one or more connecting lines is located on the first substrate; The second portion of the one or more connecting lines is attached to the lateral side of the first substrate; and The third portion of the one or more connecting lines is located on the side of the first substrate closer to the one or more signal lines, and on the side of the one or more signal lines closer to the first substrate.

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