Light-emitting substrate and display device

Abstract

The utility model discloses a light emitting substrate and a display device. The light emitting substrate comprises a substrate; the driving layer is arranged on the substrate and is provided with a plurality of conductive pads; the light-emitting units are located on the side, away from the substrate, of the driving layer, each light-emitting unit is provided with a plurality of electrodes, each electrode is electrically connected with one conductive pad through a corresponding solder part, and the solder parts comprise silver elements; wherein the orthographic projection of the electrode on the substrate is located in the orthographic projection range of the solder part on the substrate, or a part of the orthographic projection of the electrode on the substrate is a first exceeding area, the electrode comprises a first metal layer located in the first exceeding area, the first metal layer is made of silver, the first exceeding area is located outside the orthographic projection of the solder part on the substrate, and the first metal layer is made of silver. The area S of the first exceeding region meets the condition that the electrodes of the light-emitting unit comprise a first electrode and a second electrode, and L is the minimum distance between the first electrode and the second electrode.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a light-emitting substrate and a display device. Background Art

[0002] With the development of display technology, LED (mini Light-Emitting Diode) display substrates are becoming the most advantageous next-generation display media due to their advantages such as pure color, wide dynamic range, high brightness, high definition, low operating voltage, low power consumption, long life, impact resistance, wide viewing angle, and stable and reliable operation. LED display substrates include multiple LED chips arranged in an array. The research and development of LED chips, especially mini-LED and micro-LED chips, has become a major topic in the display field.

[0003] In an LED light-emitting substrate, the LED light-emitting chip is soldered to a pad through solder to achieve conduction. However, the current LED light-emitting substrate is prone to the problem of short circuit between the cathode and anode of the LED light-emitting chip. Utility Model Content

[0004] The present disclosure aims to solve at least one of the technical problems existing in the prior art, and proposes a light-emitting substrate and a display device.

[0005] The present disclosure provides a light-emitting substrate, comprising:

[0006] substrate;

[0007] a driving layer disposed on the substrate, the driving layer having a plurality of conductive pads;

[0008] a plurality of light-emitting units located on a side of the driving layer away from the substrate, the light-emitting units having a plurality of electrodes, each of the electrodes being electrically connected to one of the conductive pads via a corresponding solder portion, the solder portion comprising silver;

[0009] wherein the orthographic projection of the electrode on the substrate is located within the orthographic projection range of the solder portion on the substrate, or,

[0010] A portion of the orthographic projection of the electrode on the substrate is a first protruding area. The electrode includes a first metal layer located in the first protruding area, and the material of the first metal layer includes silver. The first protruding area is located outside the orthographic projection of the solder portion on the substrate, and an area S of the first protruding area satisfies: The electrodes of the light-emitting unit include a first electrode and a second electrode, and L is the minimum distance between the first electrode and the second electrode.

[0011] In some embodiments, L is in the range of 0.1 to 0.3 mm.

[0012] In some embodiments, the orthographic projection of the conductive pad on the substrate is within the orthographic projection range of the corresponding solder portion on the substrate, and the distance between the orthographic projection edge of the conductive pad and the orthographic projection edge of the solder portion is less than or equal to 0.16 mm.

[0013] In some embodiments, the electrode includes a first surface facing the substrate, a second surface facing away from the substrate, and a first side surface connecting the first surface and the second surface, at least a portion of the first side surface is in contact with the solder portion.

[0014] In some embodiments, the electrode includes a second metal layer, the material of the second metal layer includes a second metal, and the second metal includes copper; the material of the solder portion includes an alloy of silver, the second metal, and tin;

[0015] wherein the second metal layer is in direct contact with the solder portion, or

[0016] The electrode further includes a third metal layer located between the second metal layer and the solder portion, and a material of the third metal layer includes silver.

[0017] In some embodiments, the electrode includes a first metal layer located in the first excess region, and the electrode further includes a third metal layer;

[0018] The third metal layer and the first metal layer are connected to form an integral structure.

[0019] In some embodiments, the first electrode includes a first main portion extending along a first direction, and a first protrusion and a second protrusion connected to the first main portion on a side facing the second electrode, the first protrusion and the second protrusion are arranged along the first direction; a dimension of the first protrusion in the second direction is greater than a dimension of the second protrusion in the second direction; the second direction is a direction from the first electrode to the second electrode, and the first direction is perpendicular to the second direction;

[0020] The orthographic projection of the second protrusion on the substrate is located within the orthographic projection range of the corresponding solder portion on the substrate.

[0021] In some embodiments, the plurality of conductive pads include a first conductive pad electrically connected to the first electrode and a second conductive pad electrically connected to the second electrode;

[0022] The first conductive pad includes a second main portion extending along the first direction and at least one third protrusion connected to a side of the second main portion facing the second conductive pad, wherein an orthographic projection of the second main portion on the substrate overlaps with an orthographic projection of the first main portion on the substrate;

[0023] The orthographic projection of the first protrusion on the substrate is within the orthographic projection range of one of the third protrusions on the substrate, or the orthographic projection of the first protrusion on the substrate partially overlaps with the orthographic projection of one of the third protrusions on the substrate.

[0024] In some embodiments, the plurality of conductive pads include a first conductive pad electrically connected to the first electrode and a second conductive pad electrically connected to the second electrode;

[0025] The first conductive pad includes a second main portion extending along the first direction and at least one third protrusion connected to a side of the second main portion facing the second conductive pad, wherein an orthographic projection of the second main portion on the substrate overlaps with an orthographic projection of the first main portion on the substrate;

[0026] A portion of the orthographic projection of the second protrusion on the substrate is a second excess area, the second excess area is located outside the orthographic projection of the first conductive pad on the substrate, and the maximum distance between the edge of the second excess area and the edge of the orthographic projection of the first conductive pad does not exceed 0.16 mm.

[0027] In some embodiments, the plurality of conductive pads include a first conductive pad electrically connected to the first electrode and a second conductive pad electrically connected to the second electrode;

[0028] The first conductive pad includes a second main portion extending along the first direction and two third protrusions connected to a side of the second main portion facing the second conductive pad, wherein an orthographic projection of the second main portion on the substrate overlaps with an orthographic projection of the first main portion on the substrate;

[0029] The orthographic projection of the second protrusion on the substrate is located within the orthographic projection range of one of the third protrusions on the substrate, and the orthographic projection of the first protrusion on the substrate overlaps with the orthographic projection of another of the third protrusions on the substrate.

[0030] In some embodiments, the plurality of conductive pads include a first conductive pad electrically connected to the first electrode and a second conductive pad electrically connected to the second electrode;

[0031] The first conductive pad includes a second main portion extending along the first direction and at least one third protrusion connected to a side of the second main portion facing the second conductive pad, wherein an orthographic projection of the second main portion on the substrate overlaps with an orthographic projection of the first main portion on the substrate;

[0032] An orthographic projection of at least one of the first protrusion and the second protrusion on the substrate overlaps with an orthographic projection of the third protrusion on the substrate;

[0033] The first protrusion faces a first inner edge of the second main body, and the first inner edge extends along a third direction;

[0034] The second conductive pad includes a first edge facing the second main body and a second edge connected to the first edge, the first edge extends along the first direction, and the second edge is arranged opposite to the third protrusion; the third protrusion has a second inner edge facing the second edge, and the second inner edge and the second edge both extend along the third direction, and the third direction intersects with the first direction and the second direction.

[0035] In some embodiments, the second electrode has a third edge facing the first main portion and a fourth edge connected to the third edge, the third edge includes a straight portion and a first recessed portion, the straight portion extending in the same direction as the first main portion, the first recessed portion is disposed opposite to the second protruding portion and is curved in a direction away from the second protruding portion;

[0036] The first protrusion has a first inner edge facing the second main body; the fourth edge is arranged opposite to the first protrusion, and the fourth edge and the first inner edge both extend along a third direction, and the third direction intersects with the extension direction of the first main body and intersects with the arrangement direction of the first conductive pad and the second conductive pad.

[0037] In some embodiments, the plurality of conductive pads include a first conductive pad electrically connected to the first electrode and a second conductive pad electrically connected to the second electrode;

[0038] The first conductive pad includes a second main body and a third protrusion connected to a side of the second main body facing the second conductive pad, the light-emitting unit includes: a plurality of first electrodes located on the same side of the second electrode and arranged along a first direction, the first conductive pads being electrically connected to the first electrodes in a one-to-one correspondence;

[0039] The orthographic projection of the first electrode on the substrate is within the orthographic projection range of the corresponding first conductive pad on the substrate; or, the orthographic projection of the first electrode on the substrate covers and exceeds the orthographic projection of the first conductive pad on the substrate, and the distance between the orthographic projection edge of the first electrode and the orthographic projection edge of the first conductive pad is less than or equal to 0.16 mm.

[0040] In some embodiments, the edge of the second conductive pad facing the first conductive pad has a second recessed portion corresponding one-to-one to the third protrusion, and the second recessed portion and the corresponding third protrusion are arranged opposite to each other in a second direction, and the second direction is the direction from the first electrode to the second electrode.

[0041] In some embodiments, the light-emitting unit is electrically connected to the two first conductive pads, and among the two third protrusions of the two first conductive pads, the edge of each third protrusion toward the other third protrusion is arc-shaped, and the distance between the two opposite edges of the two third protrusions gradually increases along the direction from the first conductive pad to the second conductive pad.

[0042] In some embodiments, the plurality of conductive pads include a first conductive pad electrically connected to the first electrode and a second conductive pad electrically connected to the second electrode; and a minimum distance between the first conductive pad and the second conductive pad is in the range of 0.1 to 0.3 mm.

[0043] The present disclosure also provides a display device, comprising the above-mentioned light-emitting substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0045] Figure 1 Schematic diagram of a light-emitting substrate provided in some embodiments.

[0046] Figure 2A FIG. 4 is a plan view of a conductive pad provided in some embodiments.

[0047] Figure 2B 1 is a plan view of a light-emitting unit provided in some embodiments.

[0048] Figure 3 for Figure 2A Conductive pads and Figure 2B Schematic diagram of the electrodes of the light-emitting unit after superposition.

[0049] Figure 4Ais a cross-sectional view of an electrode provided in some embodiments.

[0050] Figure 4B This is a cross-sectional view of the connection between the light-emitting unit and the conductive pad provided in some embodiments.

[0051] Figure 5 This is a schematic diagram of a light-emitting substrate provided in some embodiments of the present disclosure.

[0052] Figure 6A This is a cross-sectional view of the electrical connection between the light-emitting unit and the conductive pad provided in some embodiments of the present disclosure.

[0053] Figure 6B Another cross-sectional view of the electrical connection between the light-emitting unit and the conductive pad provided in some embodiments of the present disclosure.

[0054] Figure 6C This is a cross-sectional view of the electrical connection between the light-emitting unit and the conductive pad provided in some other embodiments of the present disclosure.

[0055] Figure 6D This is another cross-sectional view of the electrical connection between the light-emitting unit and the conductive pad provided in other embodiments of the present disclosure.

[0056] Figure 7A This is a plan view of a conductive pad provided in some embodiments of the present disclosure.

[0057] Figure 7B This is a plan view of a light-emitting unit provided in some embodiments of the present disclosure.

[0058] Figure 7C FIG. 4 is a plan view of a solder portion provided in some embodiments of the present disclosure.

[0059] Figure 7D for Figure 7A Conductive pads and Figure 7C Plan view of the solder parts after superposition.

[0060] Figure 7E for Figure 7A Conductive pads in Figure 7B The light-emitting unit and Figure 7C A plan view of the solder parts after they are stacked.

[0061] Figure 8A It is a plan view of a conductive pad provided in some other embodiments of the present disclosure.

[0062] Figure 8B This is a plan view of a light-emitting unit provided in some other embodiments of the present disclosure.

[0063] Figure 8C 1 is a plan view of a solder portion provided in some other embodiments of the present disclosure.

[0064] Figure 8D for Figure 8A Conductive pads and Figure 8C Plan view of the solder parts after superposition.

[0065] Figure 8E for Figure 8A Conductive pads in Figure 8B The light-emitting unit and Figure 8C Plan view of the solder parts after superposition.

[0066] Figure 9A It is a plan view of a conductive pad provided in some further embodiments of the present disclosure.

[0067] Figure 9B It is a plan view of a light-emitting unit provided in some further embodiments of the present disclosure.

[0068] Figure 9C FIG. 1 is a plan view of a solder portion provided in some further embodiments of the present disclosure.

[0069] Figure 9D for Figure 9A Conductive pads and Figure 9C Plan view of the solder parts after superposition.

[0070] Figure 9E for Figure 9A Conductive pads in Figure 9B The light-emitting unit and Figure 9C Plan view of the solder parts after superposition.

[0071] Figure 10A It is a plan view of a conductive pad provided in some other embodiments of the present disclosure.

[0072] Figure 10B It is a plan view of a light-emitting unit provided in some other embodiments of the present disclosure.

[0073] Figure 10C 1 is a plan view of a solder portion provided in some further embodiments of the present disclosure.

[0074] Figure 10D for Figure 10A Conductive pads and Figure 10C Plan view of the solder parts after superposition.

[0075] Figure 10E for Figure 10A Conductive pads and Figure 10B A plan view of the superimposed light-emitting units.

[0076] Figure 11 This is a schematic diagram of a display device provided in some embodiments of the present disclosure. DETAILED DESCRIPTION

[0077] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0078] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0079] Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should have the usual meanings understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0080] As used herein, "parallel" and "perpendicular" include the conditions described and conditions similar to the conditions described, and the range of the similar conditions is within an acceptable deviation range, wherein the acceptable deviation range is determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range for approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range for approximate perpendicularity can also be, for example, a deviation within 5°.

[0081] It will be understood that when a layer or element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present therebetween.

[0082] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0083] Figure 1 Schematic diagram of a light-emitting substrate provided in some embodiments. Optionally, the light-emitting substrate can be used in a backlight module. Figure 1 As shown, the light-emitting substrate includes a driving layer 20 provided on one side of a substrate 10 and a plurality of light-emitting units 30 located on a side of the driving layer 20 away from the substrate 10. The driving layer 20 includes a plurality of conductive pads 21, and the plurality of conductive pads 21 include a plurality of first conductive pads 211 and a plurality of second conductive pads 212. The light-emitting unit 30 is, for example, a Mini-LED light-emitting chip or a Micro-LED light-emitting chip. The light-emitting unit 30 has a plurality of electrodes 31, for example, the plurality of electrodes 31 include a first electrode 311 and a second electrode 312, one of the first electrode 311 and the second electrode 312 being an anode and the other being a cathode. Each electrode 31 of the light-emitting unit 30 corresponds to a solder portion 40, and each electrode 31 is electrically connected to a conductive pad 21 through a corresponding solder portion 40. Specifically, the first electrode 311 is electrically connected to the first conductive pad 211 through the solder portion 40, and the second electrode 312 is electrically connected to the second conductive pad 212 through the solder portion 40.

[0084] Exemplarily, the light-emitting substrate may further include a reflective layer 50, the reflective layer 50 having a plurality of light-through holes, the solder portion 40 electrically connecting the electrode 31 to the conductive pad 21 through the light-through holes, and the reflective layer 50 may reflect the light of the light-emitting unit 30 to improve the light efficiency. Exemplarily, the light-emitting substrate may further include a support member 70, the support member 70 is used to support the diffuser in the backlight module, thereby providing a certain light mixing distance. Exemplarily, the light-emitting substrate also includes a circuit layer and a component 60 electrically connected to the circuit layer, the component 60 may be a driver chip, a capacitor, a resistor, a connector, and the like.

[0085] Figure 2A is a plan view of a conductive pad provided in some embodiments, Figure 2B is a plan view of a light emitting unit provided in some embodiments, Figure 3 for Figure 2A Conductive pads and Figure 2B Schematic diagram of the electrodes of the light-emitting unit after superposition, Figure 4Ais a cross-sectional view of an electrode provided in some embodiments, Figure 4B FIG. 2 is a cross-sectional view of the connection between the light emitting unit 30 and the conductive pad 21 provided in some embodiments. Figures 2A to 4B As shown, the light-emitting unit 30 includes a light-emitting portion 32, and the first electrode 311 and the second electrode 312 are electrically connected on the same side of the light-emitting portion 32. For example, the light-emitting portion 32 is located on the side of the support layer 72 away from the substrate 10, and the first electrode 311 and the second electrode 312 are located on the side of the support layer 72 close to the substrate 10. The light-emitting portion 32 is connected to the first electrode 311 and the second electrode 312 respectively through the connecting wire 71. Figure 4A As shown, each electrode 31 includes an initial metal layer 31d and a second metal layer 31b located between the initial metal layer 31a and the light-emitting portion 32. Typically, the initial metal layer 31a is a silver layer, allowing the electrode 31 to be soldered to the solder portion 40 to form an alloy. Silver has excellent thermal conductivity, electrical conductivity, solderability, and polishability at room temperature. The thickness of the initial metal layer 31a ranges from 0.1 microns to 5 microns. After the electrode 31 is soldered to the solder, at least a portion of the initial metal layer 31a reacts with the solder to form an alloy.

[0086] It should be noted that the “solder” in the present disclosure refers to the material before being soldered to the electrode 31 , for example, solder paste; and the “solder portion 40 ” refers to the alloy structure formed after soldering to the electrode 31 .

[0087] In some embodiments, the first electrode 311 includes a first main portion 3110 and a first protrusion 3111 and a second protrusion 3112 electrically connected to the first main portion 3110. The first protrusion 3111 and the second protrusion 3112 are located on a side of the first main portion 3110 close to the second electrode 312, and the first protrusion 3111 and the second protrusion 3112 are arranged along a first direction. The dimension of the first protrusion 3111 in the second direction is greater than the dimension of the second protrusion 3112 in the second direction. The second direction is the direction from the first electrode 311 to the second electrode 312, and the first direction is perpendicular to the second direction.

[0088] Exemplarily, both the first protrusion 3111 and the second protrusion 3112 extend beyond the solder pad in the second direction. In this case, during reflow soldering, a portion of the first electrode 311 is not covered by the solder, resulting in direct exposure of the silver metal in the electrode 31. For example, in one embodiment, the first protrusion 3111 and the second protrusion 3112 extend beyond the solder pad in the second direction by 0.16 mm and 0.4 mm, respectively. During reflow soldering, solder (e.g., solder paste) is applied to the conductive pad 21 and then soldered to the electrode 31. During the reflow soldering process, the solder paste climbs along the portion of the first electrode 311 that extends beyond the first conductive pad 211, hereinafter referred to as "tin creeping." The solder portion 40 formed after soldering covers a larger area on the electrode 31 than before soldering. The solder creeping distance is typically no greater than 0.16 mm. In this case, after soldering, a 0.24 mm area of ​​the first protrusion 3111 in the second direction is still not covered by the solder portion 40, resulting in exposed silver.

[0089] If a large area of ​​silver is exposed, then during a reliability test in a water vapor environment, when power is on, the exposed silver metal is ionized into silver ions. Under the action of water vapor and pressure difference, the silver ions migrate from the first electrode 311 to the second electrode 312 along the shortest path and are reduced to silver metal at the second electrode 312, thereby causing a short circuit between the first electrode 311 and the second electrode 312, and further causing abnormal luminescence of the light-emitting substrate.

[0090] In order to solve the above technical problems, the present disclosure provides a light-emitting substrate. Figure 5 This is a schematic diagram of a light-emitting substrate provided in some embodiments of the present disclosure. Figure 6A This is a cross-sectional view of the electrical connection between the light-emitting unit and the conductive pad provided in some embodiments of the present disclosure. Figure 6B This is another cross-sectional view of the electrical connection between the light-emitting unit and the conductive pad provided in some embodiments of the present disclosure. Figure 6C This is a cross-sectional view of the electrical connection between the light-emitting unit and the conductive pad provided in some other embodiments of the present disclosure. Figure 6D This is another cross-sectional view of the electrical connection between the light-emitting unit and the conductive pad provided in other embodiments of the present disclosure. Figure 7A is a plan view of a conductive pad provided in some embodiments of the present disclosure, Figure 7B is a plan view of a light emitting unit provided in some embodiments of the present disclosure, Figure 7C is a plan view of a solder portion provided in some embodiments of the present disclosure, Figure 7D for Figure 7A Conductive pads and Figure 7C The plan view of the solder parts after superposition, Figure 7E for Figure 7A Conductive pads in Figure 7B The light-emitting unit and Figure 7CA plan view of the solder parts after they are stacked. Figure 8A is a plan view of a conductive pad provided in some other embodiments of the present disclosure, Figure 8B is a plan view of a light-emitting unit provided in some other embodiments of the present disclosure, Figure 8C is a plan view of a solder portion provided in some other embodiments of the present disclosure, Figure 8D for Figure 8A Conductive pads and Figure 8C The plan view of the solder parts after superposition, Figure 8E for Figure 8A Conductive pads in Figure 8B The light-emitting unit and Figure 8C Plan view of the solder parts after superposition. Figure 9A is a plan view of a conductive pad provided in some further embodiments of the present disclosure, Figure 9B is a plan view of a light emitting unit provided in some further embodiments of the present disclosure, Figure 9C is a plan view of a solder portion provided in some further embodiments of the present disclosure, Figure 9D for Figure 9A Conductive pads and Figure 9C The plan view of the solder parts after superposition, Figure 9E for Figure 9A Conductive pads in Figure 9B The light-emitting unit and Figure 9C Plan view of the solder parts after superposition.

[0091] like Figure 5 As shown, the light-emitting substrate includes: a substrate 10, a driving layer 20 and a plurality of light-emitting units 30 provided on the substrate 10. The driving layer 20 has a plurality of conductive pads 21, and the light-emitting units 30 are located on a side of the driving layer 20 away from the substrate 10. The light-emitting units 30 have a plurality of electrodes 31, for example, the plurality of electrodes 31 include a first electrode 311 and a second electrode 312. Each electrode 31 is electrically connected to one of the conductive pads 21 through a corresponding solder portion 40. For example, the plurality of conductive pads 21 include a first conductive pad 211 electrically connected to the first electrode 311 and a second conductive pad 212 electrically connected to the second electrode 312, wherein the first electrode 311 is electrically connected to the first conductive pad 211 through a corresponding solder portion 40, and the second electrode 312 is electrically connected to the second conductive pad 212 through a corresponding solder portion 40.

[0092] In some examples, the solder portion 40 includes silver. For example, the silver in the solder portion 40 may be concentrated on one side of the solder portion 40 near the electrode 31. For example, before the light emitting unit 30 is soldered, the structure of the electrode 31 may be as follows: Figure 4A As shown in FIG, when the electrode 31 is soldered to the solder, the silver in the electrode 31 forms an alloy with the solder to form the solder portion 40. For example, the position of the solder portion 40 close to the electrode 31 is enriched with silver.

[0093] For example, the solder portion 40 includes silver elements and elements of the solder portion 40 itself before soldering (ie, solder); for another example, the solder portion 40 may also include elements of the conductive pad 21 (eg, copper elements).

[0094] For example, the material of the solder portion 40 includes an alloy of silver and tin. For another example, the material of the solder portion 40 includes an alloy of copper, tin, and silver.

[0095] For example, the material of the solder portion 40 is a silver-tin alloy. For another example, the material of the solder portion 40 is a tin-silver-copper alloy.

[0096] like Figure 6A and Figure 6B Schematically shows a first projection relationship between the electrode 31 and the solder portion 40: the orthographic projection of the electrode 31 on the substrate 10 is within the orthographic projection range of the solder portion 40 on the substrate 10. Alternatively, Figure 6C and Figure 6D : shows a second projection relationship between the electrode 31 and the solder portion 40: a portion of the orthographic projection of the electrode 31 on the substrate 10 is a first protruding area A1. The electrode 31 includes a first metal layer 31a located in the first protruding area A1. The material of the first metal layer 31a includes silver. For example, the material of the first metal layer 31a is silver. The first protruding area A1 is located outside the orthographic projection of the solder portion 40 on the substrate 10. The area S of the first protruding area A1 satisfies: Wherein, L is the minimum distance between the first electrode 311 and the second electrode 312 .

[0097] It should be noted that in Figure 6C and Figure 6D In the embodiment of the present disclosure, the second projection relationship is described using only the first electrode 311 as an example. In the embodiment of the present disclosure, the first electrode 311 and the second electrode 312 may satisfy the first projection relationship or the second projection relationship at the same time; or, one of the first electrode 311 and the second electrode 312 may satisfy the first projection relationship and the other may satisfy the second projection relationship.

[0098] It should also be noted that before welding, the film structure of the electrode 31 can be as follows: Figure 4AAs shown in , it includes an initial metal layer 31d and a second metal layer 31b; after the electrode 31 is soldered with the solder, the area of ​​the initial metal layer 31d in contact with the solder may react with the solder to form an alloy in its entirety or in part. If the area in contact with the solder does not completely form an alloy, a metal layer of a certain thickness remains. If a portion of the initial metal layer 31d is not in contact with the solder, the material of this portion remains unchanged. That is, in the present disclosure, for the first projection relationship described above, a portion of the initial metal layer 31d may be retained in the electrode 31, or it may not be retained (that is, the electrode 31 may include a silver metal layer near the solder portion 40, or it may not include a silver metal layer); for the second projection relationship described above, the first metal layer 31a is the portion of the initial metal layer 31d that is not in contact with the solder.

[0099] It should be understood that the first excess area A1 is a partial area of ​​the positive projection of the electrode 31 itself on the substrate 10 before welding, and does not include the migration area generated when silver migration occurs.

[0100] In the disclosed embodiment, the orthographic projection of the electrode 31 on the substrate 10 is within the orthographic projection of the solder portion 40 on the substrate 10, thereby allowing the solder portion 40 to cover the electrode 31, reducing or preventing the problem of short circuit between the first electrode 311 and the second electrode 312 caused by silver ion migration during reliability testing. Alternatively, a portion of the orthographic projection of the electrode 31 on the substrate 10 is a first excess area A1, which is located outside the orthographic projection of the solder portion 40 on the substrate 10, and the area S of the first excess area A1 satisfies: In this case, the area of ​​the electrode 31 not covered by the solder portion 40 is small. During the reliability test, the silver ions are insufficient to migrate to the other electrode 31 over a long distance, thereby reducing or preventing the short circuit problem between the first electrode 311 and the second electrode 312.

[0101] In some embodiments, the minimum distance L between the first electrode 311 and the second electrode 312 is greater than or equal to 0.1 mm, thereby ensuring a certain safety distance between the first electrode 311 and the second electrode 312 and reducing the occurrence of a short circuit between the first electrode 311 and the second electrode 312. Furthermore, L is within the range of 0.1 mm to 0.3 mm, thereby ensuring a certain safety distance between the first electrode 311 and the second electrode 312 while preventing the light-emitting unit 30 from occupying a large area.

[0102] In some embodiments, the minimum distance between the first conductive pad 211 and the second conductive pad 212 connected to the same light-emitting unit 30 is at least 0.1 mm to ensure a certain safety distance between the first conductive pad 211 and the second conductive pad 212, thereby reducing or preventing a short circuit between the first conductive pad 211 and the second conductive pad 212. Furthermore, the minimum distance between the first conductive pad 211 and the second conductive pad 212 connected to the same light-emitting unit 30 is within the range of 0.1 to 0.3 mm, thereby reducing or preventing a short circuit between the first conductive pad 211 and the second conductive pad 212 while preventing the light-emitting unit 30 from occupying a large area.

[0103] In some embodiments, as 6A to 6D As shown, the electrode 31 includes a first surface facing the substrate 10, a second surface facing away from the substrate 10, and a first side surface connecting the first surface and the second surface, and at least a portion of the first side surface is in contact with the solder portion 40, thereby further reducing the exposed area of ​​the silver metal layer.

[0104] In some embodiments, as 6A to 6D As shown, the electrode 31 includes a second metal layer 31b. The material of the second metal layer 31b includes a second metal, and the second metal includes copper. For example, the second metal is copper. The material of the solder portion 40 includes an alloy of silver, the second metal, and tin. For example, the material of the solder portion 40 is an alloy of silver, the second metal, and tin.

[0105] Among them, such as Figure 6A As shown, the orthographic projection of the electrode 31 on the substrate 10 is located within the orthographic projection of the corresponding solder portion 40 on the substrate 10, and the second metal layer 31b of the electrode 31 can be in direct contact with the solder portion 40. In other words, during the soldering process between the electrode 31 and the solder, the entire initial metal layer reacts with the solder to form the solder portion 40 of the alloy material.

[0106] In other examples, such as Figure 6B As shown in the figure, the orthographic projection of electrode 31 on substrate 10 is located within the orthographic projection of the corresponding solder portion 40 on substrate 10. Electrode 31 may also include a third metal layer 31c, located between second metal layer 31b and solder portion 40. The material of third metal layer 31c includes silver, for example, third metal layer 31c is a silver metal layer. In other words, during the soldering process between electrode 31 and solder, a portion of initial metal layer 31a reacts with the solder to form solder portion 40 of the alloy material; the remaining portion remains unreacted, forming third metal layer 31c. The thickness of third metal layer 31c is less than that of initial metal layer 31a.

[0107] In some other examples, such as Figure 6CAs shown in the figure, the orthographic projection of electrode 31 on substrate 10 includes the aforementioned first excess area A1. In addition to the aforementioned first metal layer 31a, electrode 31 also includes a second metal layer 31b. Second metal layer 31b can directly contact solder portion 40. That is, during the soldering process between electrode 31 and solder, all areas of the initial metal layer that come into contact with the solder react with the solder to form a solder portion 40 of the alloy material. Areas of the initial metal layer that do not come into contact with the solder (i.e., first excess area A1) do not participate in the reaction, forming first metal layer 31a.

[0108] In some other examples, such as Figure 6D As shown in the figure, the orthographic projection of the electrode 31 on the substrate 10 includes the above-mentioned first excess area A1. In addition to the above-mentioned first metal layer 31a, the electrode 31 may also include a second metal layer 31b and a third metal layer 31c located between the second metal layer 31b and the solder portion 40. The material of the third metal layer 31c includes silver. For example, the third metal layer 31c is a silver metal layer. The third metal layer 31c is connected to the first metal layer 31a as an integral structure. That is, during the welding process of the electrode 31 and the solder, the area of ​​the initial metal layer that contacts the solder partially reacts with the solder to form the solder portion 40 of the alloy material, while the other part does not react, forming the third metal layer 31c. The area of ​​the initial metal layer that does not contact the solder (i.e., the first excess area A1) does not participate in the reaction, forming the first metal layer 31a. The thickness of the third metal layer 31c is less than that of the initial metal layer 31a.

[0109] In some embodiments, the orthographic projection of the conductive pad 21 on the substrate 10 is located within the orthographic projection range of the corresponding solder portion 40 on the substrate 10, and the distance between the orthographic projection edge of the conductive pad 21 and the orthographic projection edge of the solder portion 40 is less than or equal to 0.16 mm. Specifically, when the orthographic projection of the electrode 31 on the substrate 10 is located within the orthographic projection range of the conductive pad 21 on the substrate 10, the orthographic projection of the conductive pad 21 on the substrate 10 is located within the orthographic projection range of the solder portion 40 on the substrate 10, so that the solder portion 40 can fully cover the electrode 31; when a portion of the orthographic projection of the electrode 31 on the substrate 10 exceeds the conductive pad 21, during the reflow process, the solder creeps along the electrode 31, and the creeping distance is less than or equal to 0.16 mm, that is, there is a distance of no more than 0.16 mm between the orthographic projection edge of the solder portion 40 and the orthographic projection edge of the conductive pad 21.

[0110] In some embodiments, the orthographic projection of the electrode 31 on the substrate 10 is within the orthographic projection of the solder portion 40 on the substrate 10, and the edge of the orthographic projection of the electrode 31 is retracted by 0.16 mm to obtain a first region. In one example, the orthographic projection of the conductive pad 21 on the substrate 10 at least covers the first region. In addition, a certain safety distance should be left between the conductive pads 21 connected to the first electrode 311 and the second electrode 312 of the same light-emitting unit, for example, a safety distance of at least 0.1 mm. In this case, after the conductive pad 21 is fully coated with solder and reflowed, the orthographic projection of the formed solder portion 40 on the substrate 10 can cover the orthographic projection of the electrode 31 on the substrate 10.

[0111] In some embodiments, as 7A to 9E As shown, the orthographic projection of the second electrode 312 on the substrate 10 is within the orthographic projection of the second conductive pad 212 on the substrate 10, thereby ensuring that the solder portion 40 formed on the second conductive pad 212 can fully cover the surface of the second electrode 312 facing the substrate 10. In other embodiments, a portion of the orthographic projection of the second electrode 312 on the substrate 10 may extend beyond the orthographic projection of the second conductive pad 212 on the substrate 10, with the excess distance being less than or equal to 0.16 mm. In this case, during the reflow process, the solder creeps along the second electrode 312, and the ultimately formed solder portion 40 can also cover the surface of the second electrode 312 facing the substrate 10. In other words, the orthographic projection of the second electrode 312 on the substrate 10 is within the orthographic projection of the solder portion 40 on the substrate 10.

[0112] In the embodiment of the present disclosure, the orthographic projection of the first electrode 311 on the substrate 10 may be located within the orthographic projection of the first conductive pad 211 on the substrate 10, or a portion of the orthographic projection of the first electrode 311 on the substrate 10 may extend beyond the orthographic projection of the first conductive pad 211 on the substrate 10. This will be described below with reference to specific drawings.

[0113] In some embodiments, as 7A to 9EAs shown, the first electrode 311 includes a first main portion 3110 extending along a first direction, and a first protrusion 3111 and a second protrusion 3112 connected to the first main portion 3110 on the side facing the second electrode 312. The first protrusion 3111 and the second protrusion 3112 are arranged along the first direction. The first protrusion 3111 is larger in the first direction than the second protrusion 3112 in the second direction. The second direction is the direction from the first electrode 311 to the second electrode 312, and the first direction is perpendicular to the second direction. The orthographic projection of the second protrusion 3112 on the substrate 10 is located within the orthographic projection of the corresponding solder portion 40 on the substrate 10, so that the second protrusion 3112 can be covered by the solder portion 40, reducing or preventing the problem of short circuit between the first electrode 311 and the second electrode 312 due to exposed silver.

[0114] like 7A to 9E As shown, in some embodiments, the first conductive pad 211 includes a second main body portion 2110 extending along the first direction and at least one third protrusion 2111 connected to the second main body portion 2110 on the side facing the second conductive pad 212, and the orthographic projection of the second main body portion 2110 on the substrate 10 overlaps with the orthographic projection of the first main body portion 3110 on the substrate 10. For example, the orthographic projection of the first main body portion 3110 on the substrate 10 is located within the orthographic projection range of the second main body portion on the substrate 10, which is conducive to the orthographic projection of the solder portion 40 formed on the substrate 10 after the solder is coated on the first conductive pad 211 and the reflow process is performed. It can completely cover the orthographic projection of the first main body portion 3110 on the substrate 10. For another example, a portion of the orthographic projection of the first main body portion 3110 on the substrate 10 exceeds the orthographic projection of the second main body portion 2110 on the substrate 10, and the distance between the edge of the exceeding portion and the edge of the orthographic projection of the second main body portion 2110 does not exceed 0.16 mm. Therefore, when solder is coated on the first conductive pad 211 for the reflow process, the solder climbs on the first main body portion 3110, and the orthographic projection of the formed solder portion 40 on the substrate 10 can completely cover the orthographic projection of the first main body portion 3110 on the substrate 10.

[0115] The orthographic projection of at least one of the first protrusion 3111 and the second protrusion 3112 on the substrate 10 overlaps with the orthographic projection of the third protrusion 2111 on the substrate 10 .

[0116] In some embodiments, as 7A to 7E As shown, the orthographic projection of the first protrusion 3111 on the substrate 10 is located within the orthographic projection range of one of the third protrusions 2111 on the substrate 10, thereby ensuring that the solder portion 40 on the third protrusion 2111 can cover the first protrusion 3111, thereby reducing or preventing the silver exposure on the first protrusion 3111.

[0117] In addition, if Figure 7A and Figure 7E As shown, a part of the orthographic projection of the second protrusion 3112 on the substrate 10 is the second excess area A2, and the second excess area A2 is located outside the orthographic projection of the first conductive pad 211 on the substrate 10, and the maximum distance between the edge of the second excess area A2 and the edge of the orthographic projection of the first conductive pad 211 does not exceed 0.16 mm. In this case, during reflow soldering, the solder climbs along the second protrusion 3112, and the orthographic projection of the finally formed solder portion 40 on the substrate 10 can cover the orthographic projection of the second protrusion 3112 on the substrate 10.

[0118] for 7A to 7E In the embodiment shown, after the solder portion 40 is formed between the first conductive pad 211 and the first electrode 311, and between the second conductive pad 212 and the second electrode 312, the orthographic projections of the first electrode 311 and the second electrode 312 on the substrate 10 are respectively located within the orthographic projection range of the corresponding solder portion 40 on the substrate 10.

[0119] For example, combined 7A to 7E As shown, the orthographic projection of the light-emitting unit 30 on the substrate 10 is a 1.5 mm by 1.5 mm square. The left and right edges of the square are aligned along the first direction, and the upper and lower edges of the square are aligned along the second direction. The distance from the left and right edges of the square to the second main body 2110 is 0.1 mm. The distance from the upper edge of the square to the second conductive pad 212 is 0.1 mm, and the distance from the lower edge to the second conductive pad 212 is 0.1 mm. The width of the first main body 3110 is 0.15 mm. The dimension of the first protrusion 3111 in the second direction is 0.5 mm, and the dimension of the second protrusion 3112 in the second direction is 0.26 mm. The first conductive pad 211 includes a second main portion 2110 and a third protruding portion 2111. The width of the second main portion 2110 is 0.25 mm. A portion of the orthographic projection of the second main portion 2110 on the substrate 10 (its width is 0.1 mm) is located on the side of the orthographic projection of the first main portion 3110 that is closest to the second conductive pad 212. The length of the third protruding portion 2111 in the second direction is 0.4 mm, and the orthographic projection of the third protruding portion 2111 on the substrate 10 overlaps the orthographic projection of the first protruding portion 3111 on the substrate 10. The second protruding area has a dimension of 0.16 mm in the second direction. The distance between the second protruding portion 3112 and the edge of the second conductive pad 212 facing the second main portion 2110 in the second direction is 0.14 mm. The distance between the two opposing edges of the second main portion 2110 and the second conductive pad 212 in the second direction is 0.3 mm. The closest distance between the edge of the second conductive pad 212 extending in the first direction away from the second main portion 2110 and the second edge E2 is 0.3 mm.

[0120] In other embodiments, Figures 8A to 8E As shown, the orthographic projection of the first protrusion 3111 on the substrate 10 partially overlaps with the orthographic projection of one of the third protrusions 2111 on the substrate 10. Figure 3 In terms of Figures 8A to 8E The structure can reduce the silver exposed area of ​​the first protrusion 3111.

[0121] Part of the orthographic projection of the first protrusion 3111 on the substrate 10 is located outside the orthographic projection of the third protrusion 2111 on the substrate 10. This part is referred to as the third protruding area. In one example, the solder portion 40 connected to the first protrusion 3111 extends beyond the edge of the third protrusion 2111 by 0.16 mm and completely covers the third protruding area. In another example, the solder portion 40 connected to the first protrusion 3111 extends beyond the edge of the third protrusion 2111 by 0.16 mm, and a portion of the third protruding area is located outside the orthographic projection of the solder portion 40. This portion is the first protruding area A1, and its area S satisfies the following:

[0122]

[0123] In addition, if Figures 8A to 8D As shown, a part of the orthographic projection of the second protrusion 3112 on the substrate 10 is the second excess area A2, and the second excess area A2 is located outside the orthographic projection of the first conductive pad 211 on the substrate 10, and the maximum distance between the edge of the second excess area A2 and the edge of the orthographic projection of the first conductive pad 211 does not exceed 0.16 mm. In this case, during reflow soldering, the solder climbs along the second protrusion 3112, and the orthographic projection of the finally formed solder portion 40 on the substrate 10 can cover the orthographic projection of the second protrusion 3112 on the substrate 10.

[0124] For example, in Figures 8A to 8EIn the embodiment, the orthographic projection of the light-emitting unit 30 on the substrate 10 is a 1.5 mm by 1.5 mm square. The left and right edges of the square are aligned along the first direction, and the upper and lower edges of the square are aligned along the second direction. The distance from the left and right edges of the square to the second main body 2110 is 0.1 mm. The distance from the upper edge of the square to the second conductive pad 212 is 0.1 mm, and the distance from the lower edge of the square to the second conductive pad 212 is 0.1 mm. The width of the first main body 3110 is 0.15 mm. The dimension of the first protrusion 3111 in the second direction is 0.5 mm, and the dimension of the second protrusion 3112 in the second direction is 0.26 mm. The first conductive pad 211 includes a second main body portion 2110 and a third protruding portion 2111. The width of the second main body portion 2110 is 0.25 mm. A portion of the orthographic projection of the second main body portion 2110 on the substrate 10 (its width is 0.1 mm) is located on the side of the orthographic projection of the first main body portion 3110 close to the second conductive pad 212. The length of the third protruding portion 2111 in the second direction is 0.19 mm. The size of the second protruding portion 3112 in the second direction is 0.16 mm. The distance between the second protruding portion 3112 and the edge of the second conductive pad 212 facing the second main body portion 2110 in the second direction is 0.14 mm. The distance between the two opposing edges of the second main body portion 2110 and the second conductive pad 212 in the second direction is 0.3 mm. Figures 8A to 8E In the solution, when solder is set on the first conductive pad 211 and reflow is performed, the solder climbs along the first protrusion 3111, and the climbing length is 0.16 mm. Finally, the length of the solder portion 40 on the third protrusion 2111 in the second direction is 0.19+0.16=0.35 mm, and the length of the portion of the first protrusion 3111 not covered by the solder portion 40 in the second direction (i.e., the size of the first excess area A1 in the second direction) is 0.05 mm.

[0125] In some further embodiments, Figures 9A to 9E As shown, the first conductive pad 211 includes two third protrusions 2111, which are located on a side of the second main portion 2110 near the second conductive pad 212 and arranged along the first direction. The orthographic projection of the second protrusion 3112 on the substrate 10 is located within the orthographic projection of one of the third protrusions 2111 on the substrate 10, and the orthographic projection of the first protrusion 3111 on the substrate 10 overlaps with the orthographic projection of the other third protrusion 2111 on the substrate 10.

[0126] By making the orthographic projection of the second protrusion 3112 within the orthographic projection of the third protrusion 2111, it can be further ensured that the solder portion 40 on the third protrusion 2111 can cover the second protrusion 3112, further preventing silver from leaking out of the second protrusion 3112. Figure 7E The orthographic projection of the first protrusion 3111 on the substrate 10 is the same as that of the third protrusion 2111 on the substrate 10, or the orthographic projection relationship between the first protrusion 3111 and the third protrusion 2111 is the same as that of the first protrusion 3111 on the substrate 10. Figure 8B The same as in FIG, the orthographic projection of the first protrusion 3111 on the substrate 10 partially overlaps with the orthographic projection of the third protrusion 2111 on the substrate 10.

[0127] In some embodiments, as 7A to 9E As shown, the first protrusion 3111 has a first inner edge E01 connected to the first main body 3110 and facing the second main body 2110. The first inner edge E01 extends along the third direction. The third direction intersects the first direction and the second direction. The second electrode 312 has a third edge E3 facing the first main body 3110 and a fourth edge E4 connected to the third edge E3. The third edge E3 includes a straight portion and a first recessed portion. The straight portion extends in the same direction as the first main body 3110. The first recessed portion is arranged opposite the second protrusion 3112 and curves away from the second protrusion 3112. The provision of the first recessed portion provides a clearance space for the second protrusion 3112, ensuring sufficient spacing between the second protrusion 3112 and the second electrode 312, thereby preventing a short circuit between the first electrode 311 and the second electrode 312.

[0128] In addition, the fourth edge E4 is arranged opposite to the first protrusion 3111, and the fourth edge E4 and the first inner edge E01 of the first protrusion 3111 both extend along a third direction, which intersects the extension direction of the first main body 3110 and the second direction.

[0129] During the preparation of the light-emitting substrate of the present embodiment, a light-emitting structure comprising multiple light-emitting units 30 can be fabricated. For example, the multiple light-emitting units 30 in this light-emitting structure are arranged in an array, with the multiple light-emitting units 30 in the same row connected in series, facilitating testing of the multiple light-emitting units 30. For example, the first protrusion 3111 of one of two adjacent light-emitting units 30 is integrally formed with the second electrode 312 of the other light-emitting unit 30. Accordingly, the first inner edge E01 of the first protrusion 3111 extends along the third direction, i.e., the first inner edge E01 of the first protrusion 3111 is inclined relative to the first main portion 3110, facilitating electrical connection with the second electrode 312 of the other light-emitting unit 30. Simultaneously, the fourth edge E4 is configured to extend along the third direction, thereby ensuring that the second electrode 312 has a sufficient area while leaving a sufficient gap between the fourth edge E4 and the first protrusion 3111 of the first electrode 311.

[0130] In some embodiments, as 7A to 9E As shown, the first inner edge E01 of the first protrusion 3111 extends along the third direction. Furthermore, the second conductive pad 212 includes a first edge E1 facing the second main body 2110 and a second edge E2 connected to the first edge E1. The first edge E1 extends along the first direction, and the second edge E2 is disposed opposite the third protrusion 2111. The third protrusion 2111 has a second inner edge E02 connected to the second main body 2110 and facing the second edge E2. Both the second edge E2 and the second inner edge E02 extend along the third direction, thereby ensuring that the solder portion 40 on the third protrusion 2111 fully covers the first protrusion 3111 while leaving a sufficient gap between the third protrusion 2111 and the fourth edge E4.

[0131] For example, in 7A to 7E 、 Figures 8A to 8E 、 Figures 9A to 9E There is a gap of 0.3 mm between the extension line of the second inner edge E02 of the third protrusion 2111 and the second edge E2 of the second conductive pad 212, and a gap between the first inner edge E01 of the first protrusion 3111 and the fourth edge E4 of the second electrode 312 is greater than 0.3 mm.

[0132] In some embodiments, as 7A to 7E 、 Figures 8A to 8E 、 Figures 9A to 9E As shown, the second electrode 312 may further include a fifth edge E5 connected to the third edge E3, and at least a portion of the fifth edge E5 is recessed. This facilitates the solder portion 40 on the second conductive pad 212 to be at the recessed position of the fifth edge E5, covering the side of the second electrode 312, and further reducing the silver exposed area.

[0133] Figure 10A 2 is a plan view of a light emitting unit 30 and a conductive pad 21 provided in some other embodiments of the present disclosure. Figure 10B for Figure 10A The plan view of the light emitting unit 30 and the conductive pad 21 after being stacked, and 7A to 9E Same, Figure 10A and Figure 10B In the embodiment, the plurality of electrodes 31 of the light emitting unit 30 include a first electrode 311 and a second electrode 312, and the plurality of conductive pads 21 include a first conductive pad 211 electrically connected to the first electrode 311 and a second conductive pad 212 electrically connected to the second electrode 312. The first conductive pad 211 includes a second main body 2110 and a third protrusion 2111 connected to a side of the second main body 2110 facing the second conductive pad 212.

[0134] The orthographic projection of the conductive pad 21 on the substrate 10 is within the orthographic projection of the solder portion 40 on the substrate 10, and the distance between the orthographic projection edge of the conductive pad 21 and the orthographic projection edge of the solder portion 40 is less than or equal to 0.16 mm. The orthographic projection of the electrode 31 on the substrate 10 is within the orthographic projection of the solder portion 40 on the substrate 10. For example, the orthographic projection of the electrode 31 on the substrate 10 is within the orthographic projection of the conductive pad 21 on the substrate 10. For another example, the orthographic projection of the electrode 31 on the substrate 10 may extend beyond the orthographic projection of the conductive pad 21 on the substrate 10, but the distance of the extension is less than or equal to 0.16 mm.

[0135] and 7A to 9E The difference is that in Figures 10A to 10E In the embodiment, the light-emitting unit 30 includes a plurality of first electrodes 311. For example, the light-emitting unit 30 includes two first electrodes 311. The plurality of first electrodes 311 are located on the same side of the second electrode 312 and are arranged along the first direction. The first conductive pads 211 are electrically connected to the first electrodes 311 in a one-to-one correspondence. The orthographic projection of the first electrode 311 on the substrate 10 is located within the orthographic projection range of the corresponding first conductive pad 211 on the substrate 10, thereby ensuring that the solder portion 40 formed on the first conductive pad 211 can fully cover the surface of the first electrode 311 facing the substrate 10. In other embodiments, a portion of the orthographic projection of the first electrode 311 on the substrate 10 may exceed the orthographic projection of the first conductive pad 211 on the substrate 10, and the distance between the edge of the exceeding portion and the edge of the orthographic projection of the first conductive pad 211 is less than or equal to 0.16 mm. In this case, during the reflow process, the solder creeps along the first electrode 311, and the solder portion 40 finally formed can also cover the surface of the first electrode 311 facing the substrate 10.

[0136] For example, Figures 10A to 10EAs shown, the second conductive pad 212 has a second recessed portion 212a on its edge facing the first conductive pad 211, corresponding one-to-one with the third protrusion 2111. The second recessed portion 212a and the corresponding third protrusion 2111 are arranged opposite each other in the second direction. The provision of the second recessed portion 212a provides space for the third protrusion 2111 to avoid the third protrusion 2111, ensuring sufficient spacing between the third protrusion 2111 and the second conductive pad 212, thereby preventing a short circuit between the first conductive pad 211 and the second conductive pad 212.

[0137] For example, Figures 10A to 10E As shown, the light-emitting unit 30 is electrically connected to the two first conductive pads 211. The edges of the two third protrusions 2111 of the two first conductive pads 211 are each arc-shaped, facing the other third protrusion 2111. The distance between the two opposing edges of the two third protrusions 2111 gradually increases along the direction from the first conductive pad 211 to the second conductive pad 212. This arrangement ensures that the area of ​​the first conductive pad 211 is sufficiently large while maintaining a sufficient safety distance between the first conductive pad 211 and the second conductive pad 212.

[0138] For example, in Figure 10E In the embodiment, the orthographic projection of the first electrode 311 on the substrate 10 can be located within the orthographic projection range of the first conductive pad 211 on the substrate 10 , and the orthographic projection of the second electrode 312 on the substrate 10 can be located within the orthographic projection range of the second conductive pad 212 on the substrate 10 .

[0139] For example, in Figures 10A to 10E In the embodiment, the shortest distance between the first conducting pad 211 and the second electrode 312 is 0.3 mm, and the shortest distance between the first conducting pad 211 and the second conducting pad 212 is greater than 0.3 mm.

[0140] An embodiment of the present disclosure further provides a display device, comprising the above-mentioned light-emitting substrate.

[0141] In one example, the display device includes a backlight module and a display panel located on a light-emitting side of the backlight module, and the backlight module includes the above-mentioned light-emitting substrate.

[0142] Figure 11 is a schematic diagram of a display device provided in some embodiments of the present disclosure, such as Figure 11As shown, the backlight module includes a middle frame 300, a back plate 200, a diffuser 501, and an optical film 502. The back plate 200 is fixedly connected to the middle frame 300. The light-emitting substrate is located on the back plate 200. The middle frame 300 includes a retaining wall 303, and a first supporting portion 301 and a second supporting portion 302 connected to the retaining wall 303. The edge of the diffuser 501 is supported on the first supporting portion 301, and the optical film 502 is located on the side of the diffuser 501 away from the back plate 200. The edge of the display panel 400 is supported on the second supporting portion 302. The light-emitting substrate may further include a support member 70, which is located on the substrate 10 and supports the diffuser 501.

[0143] In another example, a display device includes a display panel, and the display panel includes the above-mentioned light-emitting substrate.

[0144] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present disclosure, and such modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A light-emitting substrate, comprising: substrate; a driving layer disposed on the substrate, the driving layer having a plurality of conductive pads; a plurality of light-emitting units located on a side of the driving layer away from the substrate, the light-emitting units having a plurality of electrodes, each of the electrodes being electrically connected to one of the conductive pads via a corresponding solder portion, the solder portion comprising silver; wherein the orthographic projection of the electrode on the substrate is located within the orthographic projection range of the solder portion on the substrate, or, A portion of the orthographic projection of the electrode on the substrate is a first protruding area. The electrode includes a first metal layer located in the first protruding area, and the material of the first metal layer includes silver. The first protruding area is located outside the orthographic projection of the solder portion on the substrate, and an area S of the first protruding area satisfies: The electrodes of the light-emitting unit include a first electrode and a second electrode, and L is the minimum distance between the first electrode and the second electrode.

2. The light-emitting substrate according to claim 1, wherein L is in the range of 0.1 to 0.3 mm.

3. The light-emitting substrate according to claim 1, wherein The orthographic projection of the conductive pad on the substrate is located within the orthographic projection range of the corresponding solder portion on the substrate, and the distance between the orthographic projection edge of the conductive pad and the orthographic projection edge of the solder portion is less than or equal to 0.16 mm. The light-emitting substrate according to claim 1 , wherein: The electrode includes a first surface facing the substrate, a second surface facing away from the substrate, and a first side surface connecting the first surface and the second surface, wherein at least a portion of the first side surface is in contact with the solder portion.

5. The light-emitting substrate according to any one of claims 1 to 4, wherein The electrode includes a second metal layer, the material of the second metal layer includes a second metal, and the second metal includes copper; the material of the solder portion includes an alloy of silver, the second metal, and tin; wherein the second metal layer is in direct contact with the solder portion, or The electrode further includes a third metal layer located between the second metal layer and the solder portion, and a material of the third metal layer includes silver. The light-emitting substrate according to claim 5 , wherein: The electrode includes a first metal layer located in the first excess area, and the electrode further includes a third metal layer; The third metal layer and the first metal layer are connected to form an integral structure.

7. The light-emitting substrate according to any one of claims 1 to 4, wherein The first electrode includes a first main portion extending along a first direction, and a first protrusion and a second protrusion connected to a side of the first main portion facing the second electrode, wherein the first protrusion and the second protrusion are arranged along the first direction; The dimension of the first protrusion in the second direction is greater than the dimension of the second protrusion in the second direction; The second direction is a direction from the first electrode to the second electrode, and the first direction is perpendicular to the second direction; The orthographic projection of the second protrusion on the substrate is located within the orthographic projection range of the corresponding solder portion on the substrate.

8. The light-emitting substrate according to claim 7, wherein The plurality of conductive pads include a first conductive pad electrically connected to the first electrode and a second conductive pad electrically connected to the second electrode; The first conductive pad includes a second main portion extending along the first direction and at least one third protrusion connected to a side of the second main portion facing the second conductive pad, wherein an orthographic projection of the second main portion on the substrate overlaps with an orthographic projection of the first main portion on the substrate; The orthographic projection of the first protrusion on the substrate is within the orthographic projection range of one of the third protrusions on the substrate, or the orthographic projection of the first protrusion on the substrate partially overlaps with the orthographic projection of one of the third protrusions on the substrate.

9. The light-emitting substrate according to claim 7, wherein The plurality of conductive pads include a first conductive pad electrically connected to the first electrode and a second conductive pad electrically connected to the second electrode; The first conductive pad includes a second main portion extending along the first direction and at least one third protrusion connected to a side of the second main portion facing the second conductive pad, wherein an orthographic projection of the second main portion on the substrate overlaps with an orthographic projection of the first main portion on the substrate; A portion of the orthographic projection of the second protrusion on the substrate is a second excess area, the second excess area is located outside the orthographic projection of the first conductive pad on the substrate, and the maximum distance between the edge of the second excess area and the edge of the orthographic projection of the first conductive pad does not exceed 0.16 mm.

10. The light emitting substrate according to claim 7, wherein The plurality of conductive pads include a first conductive pad electrically connected to the first electrode and a second conductive pad electrically connected to the second electrode; The first conductive pad includes a second main portion extending along the first direction and two third protrusions connected to a side of the second main portion facing the second conductive pad, wherein an orthographic projection of the second main portion on the substrate overlaps with an orthographic projection of the first main portion on the substrate; The orthographic projection of the second protrusion on the substrate is located within the orthographic projection range of one of the third protrusions on the substrate, and the orthographic projection of the first protrusion on the substrate overlaps with the orthographic projection of another of the third protrusions on the substrate.

11. The light-emitting substrate according to claim 7, wherein The plurality of conductive pads include a first conductive pad electrically connected to the first electrode and a second conductive pad electrically connected to the second electrode; The first conductive pad includes a second main portion extending along the first direction and at least one third protrusion connected to a side of the second main portion facing the second conductive pad, wherein an orthographic projection of the second main portion on the substrate overlaps with an orthographic projection of the first main portion on the substrate; An orthographic projection of at least one of the first protrusion and the second protrusion on the substrate overlaps with an orthographic projection of the third protrusion on the substrate; The first protrusion faces a first inner edge of the second main body, and the first inner edge extends along a third direction; The second conductive pad includes a first edge facing the second main body and a second edge connected to the first edge, the first edge extends along the first direction, and the second edge is arranged opposite to the third protrusion; the third protrusion has a second inner edge facing the second edge, and the second inner edge and the second edge both extend along the third direction, and the third direction intersects with the first direction and the second direction.

12. The light-emitting substrate according to claim 7, wherein The second electrode has a third edge facing the first main portion and a fourth edge connected to the third edge, the third edge including a straight portion and a first recessed portion, the straight portion extending in the same direction as the first main portion, the first recessed portion being arranged opposite to the second protruding portion and curving in a direction away from the second protruding portion; The first protrusion has a first inner edge facing the second protrusion; the fourth edge is arranged opposite to the first protrusion, and the fourth edge and the first inner edge both extend along a third direction, and the third direction intersects with the extension direction of the first main body and intersects with the second direction.

13. The light-emitting substrate according to any one of claims 1 to 4, wherein The plurality of conductive pads include a first conductive pad electrically connected to the first electrode and a second conductive pad electrically connected to the second electrode; The first conductive pad includes a second main body and a third protrusion connected to a side of the second main body facing the second conductive pad, the light-emitting unit includes: a plurality of first electrodes located on the same side of the second electrode and arranged along a first direction, the first conductive pads being electrically connected to the first electrodes in a one-to-one correspondence; The orthographic projection of the first electrode on the substrate is within the orthographic projection range of the corresponding first conductive pad on the substrate; or, the orthographic projection of the first electrode on the substrate covers and exceeds the orthographic projection of the first conductive pad on the substrate, and the distance between the orthographic projection edge of the first electrode and the orthographic projection edge of the first conductive pad is less than or equal to 0.16 mm.

14. The light-emitting substrate according to claim 13, wherein The edge of the second conductive pad facing the first conductive pad has a second recessed portion corresponding one-to-one to the third protruding portion, and the second recessed portion and the corresponding third protruding portion are arranged opposite to each other in a second direction, and the second direction is the direction from the first electrode to the second electrode.

15. The light-emitting substrate according to claim 13, wherein The light-emitting unit is electrically connected to the two first conductive pads. Among the two third protrusions of the two first conductive pads, the edge of each third protrusion facing the other third protrusion is arc-shaped, and the distance between the two opposite edges of the two third protrusions gradually increases along the direction from the first conductive pad to the second conductive pad.

16. The light-emitting substrate according to any one of claims 1 to 4, wherein The plurality of conductive pads include a first conductive pad electrically connected to the first electrode and a second conductive pad electrically connected to the second electrode; a minimum distance between the first conductive pad and the second conductive pad is in the range of 0.1 to 0.3 mm. 17 . A display device comprising the light-emitting substrate according to claim 1 .

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