A light-emitting substrate, a display device and a manufacturing method

Abstract

The present invention provides a light-emitting substrate, a display device and a manufacturing method, which relate to the field of display technology. The light-emitting substrate can avoid the problem of oxidation of the wiring in the binding area caused by binding the light-emitting units in the light-emitting area, thereby ensuring the binding quality of the subsequent circuit board and improving the product yield. It includes a binding area and a light-emitting area, the binding area includes a plurality of first pads, and the plurality of first pads are used to bind and connect with the circuit board; any one of the plurality of first pads includes a first metal sublayer and a first conductive sublayer stacked; the material of the first metal sublayer is a metal or a metal alloy; the first conductive sublayer has oxidation resistance and covers the first metal sublayer; the light-emitting area includes a plurality of second pads, and the plurality of second pads are used to bind and connect with a plurality of light-emitting units. The present invention is used to manufacture a light-emitting substrate.

Description

Technical Field

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

[0002] Mini / Micro LED light-emitting substrates have high requirements on the resistance of metal wiring, so copper metal is often used as wiring material. In the production process of the light-emitting substrate, Mini / Micro LED binding, flexible printed circuit board or integrated circuit binding are required separately. Summary of the invention

[0003] Embodiments of the present invention provide a light-emitting substrate, a display device and a manufacturing method, wherein the light-emitting substrate can avoid the problem of oxidation of the wiring in the binding area due to binding of the light-emitting units in the light-emitting area, thereby ensuring the binding quality of subsequent circuit boards and further improving product yield.

[0004] To achieve the purpose, the embodiment of the present invention adopts the following technical solution:

[0005] In a first aspect, a light-emitting substrate is provided, comprising a binding area and a light-emitting area;

[0006] The binding area includes a plurality of first pads, and the plurality of first pads are used for binding and connecting with the circuit board; any one of the plurality of first pads includes a first metal sublayer and a first conductive sublayer which are stacked; the material of the first metal sublayer includes a metal or a metal alloy; the first conductive sublayer has oxidation resistance and covers the first metal sublayer;

[0007] The light emitting area includes a plurality of second pads, and the plurality of second pads are used for binding and connecting with a plurality of light emitting units.

[0008] Optionally, the light-emitting substrate further includes a substrate, the first conductive sublayer is located on a side away from the substrate relative to the first metal sublayer, and a material of the first conductive sublayer includes metal oxide or metal alloy.

[0009] Optionally, the material of the first metal sublayer includes copper, and the material of the first conductive sublayer includes indium zinc oxide or indium tin oxide.

[0010] Optionally, any one of the plurality of second pads includes a second metal sublayer, and the second metal sublayer is disposed in the same layer as the first metal sublayer.

[0011] Optionally, the binding area further includes a first connecting portion and a first flat layer, the first connecting portion is located on a side away from the substrate relative to the first conductive sublayer, and the first flat layer covers an area between the plurality of first pads;

[0012] The light emitting area further includes a second connecting portion and a second planar layer, the second connecting portion is located at a side away from the substrate relative to the second metal sublayer, and the second planar layer covers the area between the plurality of second pads;

[0013] Wherein, the first planar layer and the second planar layer are arranged on the same layer.

[0014] Optionally, the material of the first metal sublayer includes copper or an alloy containing molybdenum, and the material of the first conductive sublayer includes an alloy containing copper and nickel.

[0015] Optionally, any one of the multiple second pads includes a second metal sublayer and a second conductive sublayer that are stacked, and the second conductive sublayer is located on a side away from the substrate relative to the second metal sublayer; wherein the second metal sublayer is arranged on the same layer as the first metal sublayer, and the second conductive sublayer is arranged on the same layer as the first conductive sublayer.

[0016] Optionally, the binding area further includes a first connection portion, and a first protection layer and a first flat layer that are stacked, wherein the first connection portion is located on a side of the first conductive sublayer away from the substrate, and the first flat layer is located on a side of the first protection layer away from the substrate and covers an area between the plurality of first pads;

[0017] The light-emitting area further includes a second connection portion, and a second protection layer and a second flat layer which are stacked, wherein the second connection portion is located on a side of the second conductive sublayer away from the substrate, the second protection layer covers an area between the plurality of second pads, and the second flat layer is located on a side of the second protection layer away from the substrate;

[0018] The first protection layer and the second protection layer are arranged on the same layer, and the first planarization layer and the second planarization layer are arranged on the same layer.

[0019] Optionally, the light-emitting substrate further includes a substrate;

[0020] The plurality of first solder pads are exposed facing the surface of the substrate for binding the circuit board; the plurality of second solder pads are exposed away from the surface of the substrate for binding the light emitting unit.

[0021] Optionally, the plurality of second pads are divided into a plurality of groups of second pads, and each group of the second pads includes a cathode pad and an anode pad arranged in pairs;

[0022] The light-emitting substrate further includes a substrate, a first routing line, a second routing line arranged on the same layer as the plurality of second pads, and a third flat layer, wherein the first routing line is arranged close to the substrate relative to the second routing line, and the third flat layer is arranged close to the substrate relative to the second routing line and covers the first routing line;

[0023] The first trace is electrically connected to at least one of the plurality of first pads, and is used to transmit an electrical signal provided by the circuit board;

[0024] The second routing line is used to realize series connection or parallel connection of multiple groups of the second pads, and is also used to be electrically connected to the first routing line through a via hole penetrating the third planar layer.

[0025] In a second aspect, a display device is provided, comprising: the above-mentioned light-emitting substrate, a circuit board and a plurality of light-emitting units;

[0026] The circuit board is electrically connected to a plurality of first pads of the light emitting substrate, and the plurality of light emitting units are electrically connected to a plurality of second pads of the light emitting substrate.

[0027] In a third aspect, a method for manufacturing a display device is provided, comprising:

[0028] forming the above-mentioned light-emitting substrate;

[0029] Binding a plurality of light-emitting units to a plurality of second pads of the light-emitting substrate;

[0030] A plurality of first solder pads are bonded to the circuit board and the light emitting substrate.

[0031] The embodiment of the present invention provides a light-emitting substrate, a display device and a manufacturing method, including a binding area and a light-emitting area; the binding area includes a plurality of first pads, the plurality of first pads are used to bind and connect with a circuit board; any one of the plurality of first pads includes a first metal sublayer and a first conductive sublayer stacked; the material of the first metal sublayer includes a metal or a metal alloy; the first conductive sublayer has oxidation resistance and covers the first metal sublayer; the light-emitting area includes a plurality of second pads, the plurality of second pads are used to bind and connect with a plurality of light-emitting units. In the light-emitting substrate, since the first pad of the binding area includes the first metal sublayer and the first conductive sublayer, and the first conductive sublayer has oxidation resistance and covers the first metal sublayer; then, in the manufacturing process of the light-emitting substrate, when the light-emitting unit is connected to the second pad in the light-emitting area, the first conductive sublayer of the binding area will not be oxidized, thereby ensuring the binding quality of the subsequent circuit board, thereby improving the product yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 A schematic diagram of a partial structure of a light-emitting substrate provided by an embodiment of the present invention;

[0034] Figure 2 For along Figure 1 A schematic cross-sectional view of the AA' direction;

[0035] Figure 3 For Figure 2 A schematic diagram of a structure after a light emitting diode and a packaging layer are formed on the basis of the light emitting diode;

[0036] Figure 4-7 A schematic diagram of the manufacturing process structure of another display device provided by an embodiment of the present invention;

[0037] Figure 8-9 A schematic diagram of the manufacturing process structure of another display device provided by an embodiment of the present invention;

[0038] Figure 10-13 A schematic diagram of the manufacturing process structure of another display device provided by an embodiment of the present invention;

[0039] Figure 14-20 A schematic diagram of the manufacturing process structure of another display device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] In the embodiments of the present invention, words such as "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. This is only for the purpose of clearly describing the technical solutions of the embodiments of the present invention, and shall not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0042] In the embodiments of the present invention, “plurality” means two or more than two, unless otherwise clearly and specifically defined.

[0043] In the embodiments of the present invention, the orientation or positional relationship indicated by the term "on" or the like is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0044] Mini-LED (submillimeter light-emitting diode) refers to a light-emitting diode with a size between 80 and 300um. When Mini-LED is used as the pixel point of the display panel to form a self-luminous display, a higher pixel density can be achieved compared to a small-pitch LED display. When Mini-LED is used as a light source in a backlight module, an ultra-thin light source module can be made through a denser arrangement of light sources; combined with regional dimming technology, the display screen including the Mini-LED backlight module will have better contrast and high dynamic lighting rendering display effects. Micro LED micro light-emitting diodes with a size less than 80um can be directly used as pixels of display panels such as near-eye, wearable, and handheld terminals.

[0045] The light-emitting substrate described in the present application may refer to a substrate used to provide a light source or a substrate used for display, without limitation.

[0046] In the related art, in order to complete the binding of Mini / Micro LED and the light-emitting substrate, it is necessary to set solder paste on the pads on the light-emitting substrate to be electrically connected to the Mini / Micro LED, then transfer the Mini / Micro LED to the corresponding position on the light-emitting substrate, and then fix the Mini / Micro LED and the light-emitting substrate by reflow soldering in the temperature range of 230℃-260℃. Then, the circuit board is bound to the pads on the light-emitting substrate to be electrically connected to the circuit board by hot pressing in the temperature range of 130℃-150℃.

[0047] The inventors found that since different process conditions are required to bind the Mini / Micro LED and the circuit board to the light-emitting substrate, the two cannot be bound simultaneously. Therefore, when one of them is bound, the metal at the pad on the light-emitting substrate corresponding to the other is easily oxidized, which makes it impossible to ensure good electrical connection later, thereby reducing the product yield.

[0048] An embodiment of the present invention provides a light-emitting substrate, which can be configured to be used for display or providing backlight, and includes a binding area and a light-emitting area.

[0049] refer to Figure 2 and Figure 6As shown, the binding area OA includes a plurality of first pads 1, which are used for binding and connecting with the circuit board; any one of the plurality of first pads includes a first metal sublayer 11 and a first conductive sublayer 12 which are stacked; the material of the first metal sublayer includes metal or metal alloy; the first conductive sublayer has oxidation resistance and covers the first metal sublayer.

[0050] The light emitting area OB includes a plurality of second pads, and the plurality of second pads are used for binding and connecting with a plurality of light emitting units.

[0051] The material of the first metal sublayer includes metals, such as copper, aluminum, molybdenum, titanium, etc. Considering that copper has low resistivity and strong conductivity, copper is preferably used to make the first metal sublayer; at this time, the material of the first conductive sublayer can be a metal oxide or a metal alloy, for example, the metal oxide can be indium zinc oxide (IZO) or indium tin oxide (ITO). If the material of the first metal sublayer includes a metal alloy, for example, an alloy containing molybdenum; at this time, the material of the first conductive sublayer can be a metal alloy, for example, the metal alloy is a copper-containing alloy, such as a copper-nickel alloy. The first conductive sublayer has oxidation resistance and conductivity, thereby avoiding the problem of oxidation in the process of making the light-emitting substrate. Therefore, the first conductive sublayer can protect the first metal sublayer and avoid oxidation of the first metal sublayer in the process of making the light-emitting substrate.

[0052] The specific structure of the second pad is not limited and can be determined according to actual requirements.

[0053] In the embodiments provided in the present disclosure, the light-emitting substrate may be a display light-emitting substrate or a backlight light-emitting substrate. If it is a display light-emitting substrate, the light-emitting area OB constitutes a display area to realize a display image. If it is a backlight light-emitting substrate, the light-emitting area OB is used to provide a light source.

[0054] Here, there is no limitation on the luminous color of the luminous area included in the luminous substrate; the luminous area can be any one of a red luminous area, a green luminous area or a blue luminous area. The luminous substrate can include luminous areas of three luminous colors: a red luminous area, a green luminous area or a blue luminous area; of course, it can also include luminous areas of only one luminous color, for example: only multiple red luminous areas, or only multiple green luminous areas, or only multiple blue luminous areas. The specifics can be determined according to actual requirements.

[0055] The control method of the multiple light-emitting areas is not limited. For example, each light-emitting area can be controlled independently, or multiple light-emitting areas can be controlled simultaneously.

[0056] In the embodiments provided by the present disclosure, Figure 3 and Figure 7As shown, the light-emitting substrate may further include a substrate 7 and a plurality of light-emitting units formed on the substrate 7. The light-emitting units may include Figure 7 or Figure 3 The light emitting diode 6 is shown. The material of the substrate can be a rigid material, such as glass, or a flexible material, such as polyimide.

[0057] It should be noted that, since the light-emitting diode includes an anode and a cathode, one light-emitting diode needs to be bound through two second pads. The above-mentioned multiple second pads can be divided into multiple groups of second pads, each group of second pads is used to bind one light-emitting diode, and includes a cathode pad and an anode pad arranged in pairs, wherein the second pad bound to the cathode of the light-emitting diode is called a cathode pad, and the second pad bound to the anode of the light-emitting diode is called an anode pad. In the drawings of the embodiments of the present invention, different markings are used to clearly distinguish between the cathode pad and the anode pad. For details, refer to Figure 1 and Figure 2 As shown, the cathode pad is marked as 2' and the anode pad is marked as 2, but the film layer structure included in both is the same.

[0058] The distribution structure and connection method of the plurality of first pads and the plurality of second pads in the above-mentioned light-emitting substrate are not limited. Figure 1 As shown, region OA is a binding region, region OB is a light-emitting region, and a plurality of second pads can be divided into a plurality of groups of second pads. Each group of second pads is used to bind a light-emitting diode and includes a cathode pad 2' and an anode pad 2 arranged in pairs. Two adjacent groups of second pads are connected in series through a trace 81; among the two groups of second pads in series, the anode pad of one group is connected to a trace 82 and is electrically connected to the anode trace 51 through a via 4, and the anode trace 51 is connected to the anode trace 51 through a via ( Figure 1 The cathode pad of another group is connected to another trace 82 and is electrically connected to the cathode trace 52 through another via 4. The cathode trace 52 is electrically connected to the cathode trace 52 through the via ( Figure 1 The first pad 1 is electrically connected to the other first pad 1. Figure 1 In the figure, the cathode pad 2', the anode pad 2, the first pad 1, the trace 81 and the trace 82 are arranged on the same layer and use the same filling pattern; the anode trace 51 and the cathode trace 52 are arranged on the same layer and use the same filling pattern.

[0059] Figure 2 for Figure 1 A schematic cross-sectional view along the AA' direction, Figure 6 for Figure 1 Another cross-sectional diagram along the AA' direction, Figure 3 is Figure 2 Schematic diagram of the structure after the light emitting diode 6 and the packaging layer 9 are formed on the basis. Figure 7is Figure 6 Schematic diagram of the structure after the light emitting diode 6 and the packaging layer 9 are formed on the basis.

[0060] It is understandable that the present application does not limit the driving method of the light-emitting substrate. Figure 1 As shown, the light-emitting substrate drives the light-emitting unit in a passive manner, or a driving circuit including a thin film transistor can be used to provide a signal to the light-emitting unit, or a microchip can be used to provide a signal to the light-emitting unit.

[0061] An embodiment of the present invention provides a light-emitting substrate, in which the first soldering pad in the binding area includes a first metal sublayer and a first conductive sublayer, and the first conductive sublayer is anti-oxidative and covers the first metal sublayer; therefore, during the manufacturing process of the light-emitting substrate, when the light-emitting unit is bound and connected to the second soldering pad in the light-emitting area, the first conductive sublayer in the binding area will not be oxidized, thereby ensuring the binding quality of the subsequent circuit board and further improving the product yield.

[0062] Optional, reference Figure 2 and Figure 6 As shown, the light-emitting substrate includes a substrate 7, and the first conductive sublayer 12 is located on a side away from the substrate 7 relative to the first metal sublayer 11, and the material of the first conductive sublayer includes metal oxide or metal alloy.

[0063] Optionally, the material of the first metal sublayer includes copper, and the material of the first conductive sublayer includes indium zinc oxide or indium tin oxide. Considering that indium zinc oxide has better conductivity and lower resistivity, indium zinc oxide is generally used to make the first conductive sublayer to avoid oxidation of the first metal sublayer made of copper during the process of making the light-emitting substrate.

[0064] Further optional, refer to Figure 6 As shown, any one of the plurality of second pads includes a second metal sub-layer 21 , and the second metal sub-layer 21 is disposed in the same layer as the first metal sub-layer 11 .

[0065] The same-layer arrangement refers to the use of a one-time patterning process. A one-time patterning process refers to forming the required pattern through a one-time film formation and photolithography process. A one-time patterning process includes processes such as film formation, exposure, development, etching and stripping. The second metal sublayer is arranged on the same layer as the first metal sublayer, thereby reducing the number of patterning processes, simplifying the manufacturing process, and significantly reducing production costs.

[0066] It should be noted that making Figure 6 When the display substrate shown in FIG. 1 is used, the following can be made: Figure 4 The display substrate is shown. Figure 4In the embodiment provided in the present disclosure, the material of the first metal sublayer includes copper, and the material of the first conductive sublayer includes indium zinc oxide or indium tin oxide. The second metal sublayer is arranged in the same layer as the first metal sublayer, and the second conductive sublayer is arranged in the same layer as the first conductive sublayer, then the material of the second metal sublayer includes copper, and the material of the second conductive sublayer includes indium zinc oxide or indium tin oxide. Then, if the reflow soldering process is used to complete the binding of the light-emitting unit and the light-emitting substrate, it is necessary to set solder paste between the light-emitting unit and the second solder pad of the light-emitting substrate. Since indium zinc oxide or indium tin oxide cannot achieve a good and fixable contact interface with solder paste, and the material of the second conductive sublayer includes indium zinc oxide or indium tin oxide, solder paste cannot be directly set on the second conductive sublayer, and the second conductive sublayer in the second solder pad needs to be removed to expose the second metal sublayer, thereby obtaining the following. Figure 6 The display substrate shown. The material of the second metal sublayer includes copper, which can be bonded with solder paste, so that the light-emitting unit is bound to the second metal sublayer through a reflow soldering bonding process. The circuit board is generally bonded to the first conductive sublayer by heat curing glue and hot pressing, without removing the part of the first conductive sublayer used for bonding to the circuit board.

[0067] In addition, the materials of the first metal sublayer and the second metal sublayer include copper. In order to increase the adhesion of copper and reduce the difficulty of manufacturing, the first pad may also include a first buffer sublayer, and the first metal sublayer is located on the first buffer sublayer; the second pad may also include a second buffer sublayer, and the second metal sublayer is located on the second buffer sublayer; the first buffer sublayer and the second buffer sublayer are arranged in the same layer, and the material may be a molybdenum-containing alloy, for example: molybdenum-titanium-nickel alloy.

[0068] In the light-emitting substrate, since the first pad in the binding area includes a first metal sublayer and a first conductive sublayer, and the first conductive sublayer is resistant to oxidation and covers the first metal sublayer; therefore, during the manufacturing process of the light-emitting substrate, when the light-emitting unit and the second metal sublayer are bound to the light-emitting area, the first metal sublayer in the binding area will not be oxidized due to the protection of the first conductive sublayer, thereby ensuring the binding quality of the subsequent circuit board and further improving the product yield.

[0069] Further optional, refer to Figure 2-9 As shown, the binding area OA also includes a first connecting portion (not shown) and a first planar layer 14, wherein the first connecting portion is located on a side away from the substrate relative to the first conductive sublayer, and the first planar layer covers the area between the plurality of first pads and exposes the surfaces of the first pads and the second pads.

[0070] The light emitting area OB also includes a second connecting portion (such as Figure 710) and a second planar layer 24, the second connection portion is located on a side away from the substrate relative to the second metal sub-layer, and the second planar layer covers the area between the plurality of second pads.

[0071] The first flat layer and the second flat layer are arranged on the same layer to form an integrated structure.

[0072] The first planarization layer and the second planarization layer can protect the first wiring layer and the second wiring layer respectively, and also play a planarization role to facilitate subsequent processes. The material thereof can be an organic material, such as resin.

[0073] The material of the first connection part may be a thermosetting adhesive, and the material of the second connection part may be a solder paste, a copper paste, or the like.

[0074] In related technologies, such as Fig. 20 As shown, a silicon oxynitride (SiON) insulating layer 104 is also provided between the second resin layer 105 and the thin copper layer 103. However, in the light-emitting substrate provided in the embodiment of the present invention, since a second conductive sublayer is provided above the first metal sublayer, the second metal sublayer is well protected. Therefore, the light-emitting substrate removes the silicon oxynitride insulating layer of the original process, thereby eliminating the PECVD (Plasma Enhanced Chemical Vapor Deposition) process and the silicon oxynitride etching process in the original process, simplifying the original process flow and reducing the manufacturing cost.

[0075] It should be noted that the reference Figure 7 As shown, the light-emitting substrate may further include an encapsulation layer 9 located on and covering the light-emitting unit 6 to play a role of protection and encapsulation. The material of the encapsulation layer may be silica gel.

[0076] In order to facilitate driving, the light-emitting substrate may further include a first wiring located on the substrate and a second wiring arranged on the same layer as the second pad. Figure 1 As shown, the first wiring includes an anode wiring 51 and a cathode wiring 52, and the second wiring includes a wiring 81 and a wiring 82. Figure 6 As shown, the trace 82 includes a third metal sublayer 83 and a third conductive sublayer 84, and the third metal sublayer 83 is connected to the second metal sublayer 21. Figure 6 Separated by dotted lines.

[0077] refer to Figure 6As shown, the anode wiring 51 may include only one layer of structure; or, it may also include a first molybdenum-titanium-nickel alloy sublayer, a copper sublayer, and a second molybdenum-titanium-nickel alloy sublayer stacked in sequence. In order to reduce the voltage drop (IRDrop), the copper sublayer uses thick copper (compared to the copper thickness of the first conductive sublayer). The thickness of the copper is related to the product size of the Mini-LED backplane. The larger the size, the greater the required copper thickness. The first molybdenum-titanium-nickel alloy sublayer, the copper sublayer, and the second molybdenum-titanium-nickel alloy sublayer can be sequentially manufactured by sputtering process. The second molybdenum-titanium-nickel alloy sublayer can protect the copper sublayer and prevent the surface of the copper sublayer from oxidation.

[0078] Furthermore, to protect and insulate the first trace, refer to Figure 6 As shown, the light-emitting substrate may further include a third flat layer 33 covering the first wiring, the first pad 1 and the second pad 2 are located on the third flat layer 33, and the material of the third flat layer may be an organic material, such as resin. Figure 6 As shown, the first metal sub-layer 11 and the third metal sub-layer 83 are connected through vias ( Figure 6 The two electrodes (not shown) are electrically connected to the anode wiring 51 respectively.

[0079] In the embodiments provided in the present disclosure, the material of the first metal sublayer includes copper or an alloy containing molybdenum, and the material of the first conductive sublayer includes an alloy containing copper and nickel.

[0080] If the material of the first metal sublayer includes copper, in order to increase the adhesion of copper and reduce the difficulty of manufacturing, the first pad may also include a first buffer sublayer, and the first metal sublayer is located on the first buffer sublayer. In this case, the first pad includes a three-layer structure of the first buffer sublayer, the first metal sublayer (copper layer) and the first conductive sublayer (copper-nickel alloy layer). The material of the first buffer sublayer may be a molybdenum-containing alloy, and its thickness may be The thickness of the first metal sub-layer can range from The thickness of the first conductive sublayer may range from

[0081] If the material of the first metal sub-layer includes an alloy containing molybdenum, then, reference Figure 2 As shown, the first pad 1 includes a first metal sublayer (molybdenum alloy layer) 11 and a first conductive sublayer (copper-nickel alloy layer) 12. The thickness of the first metal sublayer can be The thickness of the first conductive sublayer may range from

[0082] Whether the first pad adopts a two-layer structure or a three-layer structure needs to be determined according to the resistance requirement.

[0083] The material of the first conductive sublayer includes an alloy containing copper and nickel, and the target material ratio of the copper-nickel alloy can be selected according to the resistance requirements and etching conditions. Theoretically, the higher the nickel content, the stronger its oxidation resistance. However, nickel is magnetic. If the nickel content is too high, on the one hand, it will increase the difficulty of making the target material, and on the other hand, it will increase the difficulty of subsequent patterning. Therefore, the nickel ratio cannot be too high. After a lot of research, the applicant found that the ratio range can be selected between Cu:Ni=70:30~95:5. Within the ratio range, it can be ensured that the copper-nickel alloy surface will not oxidize at a temperature of 300°C. At present, the copper-nickel alloy with Cu:Ni=80:20 can withstand high temperatures for half an hour without being oxidized in an environment of 230°. Table 1 shows the difference in resistance under different ratios.

[0084] Table 1

[0085] Material Film thickness / A Sheet resistance (Ω / □) Cu 880 0.35 CuNi(70∶30) 800 5.3 CuNi(90∶10) 3800 0.4 CuNi(95∶5) 3300 0.38

[0086] Optional, reference Figure 2 As shown, any one of the multiple second pads includes a second metal sublayer 21 and a second conductive sublayer 22 which are stacked, and the second conductive sublayer 22 is located on a side away from the substrate 7 relative to the second metal sublayer 21; wherein the second metal sublayer is arranged on the same layer as the first metal sublayer, and the second conductive sublayer is arranged on the same layer as the first conductive sublayer.

[0087] The same-layer arrangement refers to the use of a one-time patterning process. A one-time patterning process refers to forming the required pattern through a one-time film forming and photolithography process. A one-time patterning process includes processes such as film forming, exposure, development, etching and stripping. The second metal sublayer is arranged on the same layer as the first metal sublayer, and the second conductive sublayer is arranged on the same layer as the first conductive sublayer, thereby reducing the number of patterning processes, simplifying the manufacturing process, and significantly reducing production costs.

[0088] The second metal sublayer is arranged in the same layer as the first metal sublayer. If the material of the first metal sublayer includes copper, at this time, the material of the second metal sublayer also includes copper. In order to increase the adhesion of copper and reduce the difficulty of production, the second pad may also include a second buffer sublayer, and the second metal sublayer is located on the second buffer sublayer. The second buffer sublayer is arranged in the same layer as the first buffer sublayer. At this time, the second pad includes a three-layer structure of a second buffer sublayer, a second metal sublayer (copper layer) and a second conductive sublayer (copper-nickel alloy layer). If the material of the first metal sublayer includes an alloy containing molybdenum, at this time, the material of the second metal sublayer also includes an alloy containing molybdenum, and the second pad includes a two-layer structure of a second metal sublayer (molybdenum alloy layer) and a second conductive sublayer (copper-nickel alloy layer). The thickness range of each sublayer can refer to the thickness range of each sublayer included in the aforementioned first pad, which will not be repeated here.

[0089] The second conductive sublayer is arranged at the same time as the first conductive sublayer. If the material of the first conductive sublayer includes an alloy containing copper and nickel, then the material of the second conductive sublayer also includes an alloy containing copper and nickel. The ratio range of copper and nickel in the copper and nickel alloy can refer to the relevant description of the first conductive sublayer mentioned above, which will not be repeated here.

[0090] In the light-emitting substrate, since the first pad in the binding area includes the first metal sublayer and the first conductive sublayer, and the first conductive sublayer is resistant to oxidation and covers the first metal sublayer; then, during the manufacturing process of the light-emitting substrate, when the light-emitting unit and the second conductive sublayer are bound in the light-emitting area, if the material of the first metal sublayer includes copper, the first conductive sublayer protects the first metal sublayer, thereby preventing the first metal sublayer from being oxidized; if the material of the first metal sublayer includes an alloy containing molybdenum, and the material of the first conductive sublayer includes an alloy containing copper and nickel, the first conductive sublayer is resistant to oxidation and will not be oxidized. In summary, both situations can avoid the oxidation of the first wiring layer in the binding area when the light-emitting unit and the second conductive sublayer are bound in the light-emitting area; thereby ensuring the binding quality of the subsequent circuit board, and then improving the product yield.

[0091] Further optional, refer to Figure 2 As shown, the binding area OA also includes a first connecting portion ( Figure 4 The first connecting portion is located on a side of the first conductive sublayer away from the substrate, and the first flat layer is located on a side of the first protective layer away from the substrate and covers the area between the plurality of first pads.

[0092] refer to Figure 2 As shown, the light emitting area OB also includes a second connecting portion ( Figure 3 Marked as 10), and a second protective layer 23 and a second flat layer 24 are stacked, the second connection portion is located on the side of the second conductive sublayer away from the substrate, the second protective layer covers the area between multiple second pads, and the second flat layer is located on the side of the second protective layer away from the substrate.

[0093] The first protective layer and the second protective layer are disposed on the same layer to form an integrated structure; the first flat layer and the second flat layer are disposed on the same layer to form an integrated structure.

[0094] The first protection layer and the second protection layer are arranged on the same layer, and their materials may be silicon oxynitride, silicon nitride, etc.; the first planarization layer and the second planarization layer are arranged on the same layer, and their materials may be organic materials, such as resin, for planarization to facilitate subsequent processes.

[0095] The material of the first connection part may be a thermosetting adhesive, and the material of the second connection part may be a solder paste, a copper paste, or the like.

[0096] The light-emitting substrate may further include a first wiring located on the substrate and a second wiring arranged on the same layer as the second pad. Figure 1 As shown, the first wiring includes an anode wiring 51 and a cathode wiring 52, and the second wiring includes a wiring 81 and a wiring 82. Figure 2 As shown, the trace 82 includes a third metal sublayer 83 and a third conductive sublayer 84, and the third metal sublayer 83 is connected to the second metal sublayer 21. Figure 6 Separated by dotted lines.

[0097] refer to Figure 2 As shown, in the first wiring, the anode wiring 51 may include only one layer structure; or, it may also include a first molybdenum alloy sublayer and a copper sublayer stacked in sequence. Further, in order to prevent the copper sublayer from being oxidized, refer to Figure 2 As shown, the light-emitting substrate may further include a third protective layer 34 covering the wiring 51. The material of the third protective layer may be silicon oxynitride, silicon nitride, etc. Further, in order to planarize to facilitate subsequent processes, refer to Figure 2 As shown, the light-emitting substrate may further include a third flat layer 33 located on the third protective layer 34, the first pad and the second pad are located on the third flat layer 33, and the first metal sublayer 11 and the third metal sublayer 83 are electrically connected to the anode wiring 51 through vias penetrating the third flat layer and the third protective layer. The material of the third flat layer may be an organic material, such as resin. It should be noted that the anode wiring may further include a second molybdenum alloy sublayer located on the copper sublayer, in which case the copper sublayer is protected by the second molybdenum alloy sublayer, and then there is no need to form a third protective layer later. Figure 2 In order to improve the adhesion of the third wiring layer and reduce stress, the light-emitting substrate may further include a buffer layer between the substrate and the first wiring, and the material of the buffer layer may be polyimide or other materials.

[0098] In the embodiments provided in the present disclosure, reference is made to Fig.13 As shown, the light-emitting substrate also includes a substrate 7; a plurality of first pads 1 are exposed on the surface facing the substrate 7 for binding the circuit board 5; a plurality of second pads (anode pads 2 and cathode pads 2') are exposed away from the surface of the substrate 7 for binding the light-emitting unit 6.

[0099] refer to Fig.13 As shown, the light-emitting substrate may further include a peeling layer 44, and the peeling layer 44 is located between the substrate 7 and the first pad 1. The substrate 7 and the peeling layer 44 at least correspond to the area of ​​the first pad 1 for binding the circuit board 5 ( Fig.12The material of the peeling layer can be a mechanically peelable material. The material of the substrate can be a rigid substrate, such as glass, or a flexible substrate, such as polyimide.

[0100] It should be noted that Figure 10-13 In the figure, only the structures of the first pad and the second pad are schematically illustrated, and the multi-layer structure included in the first pad is not reflected.

[0101] In the light-emitting substrate, the first pad includes a first metal sublayer and a first conductive sublayer. Then, when the light-emitting unit and the second metal sublayer are bound, the first pad in the binding area will not be oxidized, thereby ensuring the binding quality of the subsequent circuit board and the first conductive sublayer, thereby improving the product yield. In addition, in the light-emitting substrate, the circuit board is bound to the side of the first metal sublayer close to the peeling layer, thereby reducing the non-luminous area of ​​the light-emitting side, thereby achieving a narrower frame.

[0102] For further reference, Fig.13 As shown, the light-emitting substrate further includes a first organic layer 41, and a protective layer 43 and a second organic layer 42 which are stacked, wherein the first organic layer 41 covers the first pad 1, and the second organic layer is located on a side of the protective layer away from the substrate and covers the area between the plurality of second pads. Fig.13 As shown, the light-emitting substrate may further include an anode wiring 82 disposed on the same layer as the second pad, and the anode wiring 82 passes through a via hole ( Fig.13 The anode wiring 82 is connected to the anode pad 2. Fig.13 In the light-emitting substrate, the anode pad 2 and the cathode pad 2' are electrically connected to the anode and cathode of the light-emitting diode 6 through the second connecting portion 10, and the circuit board 5 is electrically connected to the anode and cathode of the light-emitting diode 6 through the first connecting portion ( Fig.13 The first pad 1 is electrically connected to the first organic layer 41 (not shown). In the light-emitting substrate, the first pad 1 is located below the first organic layer 41, and the second pad 1 is located above the first organic layer 41.

[0103] In the first pad, the material of the first metal sublayer may be copper or an alloy containing molybdenum, and the material of the first conductive sublayer may be a metal oxide (e.g., indium zinc oxide, indium tin oxide) or a metal alloy (e.g., an alloy containing copper and nickel). If the material of the first metal sublayer includes copper, then the first pad may also include an alloy sublayer containing molybdenum disposed below the first metal sublayer to facilitate the manufacture of the first metal sublayer. It should be noted that, in the case where the light-emitting substrate further includes a first organic layer, a protective layer, and a second organic layer, since the circuit board is bound to the side of the first metal sublayer close to the peeling layer, it is not necessary to set a via in the area of ​​the first organic layer, the protective layer, and the second organic layer corresponding to the first metal sublayer to expose the first pad; then, when the light-emitting unit and the second metal sublayer are bound, the first organic layer, the protective layer, and the second organic layer can protect the first pad to prevent it from being oxidized. At this time, the first pad may include only the first metal sublayer (e.g., copper sublayer, etc.) or the first conductive sublayer (e.g., copper-nickel sublayer, etc.). The material of the first organic layer may be polyimide, and the material of the second organic layer may be resin.

[0104] The second pad may include only one metal sublayer, which may be a copper sublayer or a copper-containing alloy sublayer (eg, a copper-nickel alloy sublayer); of course, it may also include multiple sublayers. Considering the full use of the original process and reducing the production cost, the former is selected.

[0105] It should be noted that the reference Fig.13 As shown, the light-emitting substrate may further include an encapsulation layer 9 located on the cover of the light-emitting unit to play a role of protection and encapsulation. The material of the encapsulation layer may be silica gel.

[0106] Optional, reference Figure 1 As shown, the plurality of second pads are divided into a plurality of groups of second pads, and each group of second pads includes a cathode pad 2 ′ and an anode pad 2 arranged in pairs.

[0107] The light-emitting substrate also includes a substrate, a first routing line, a second routing line arranged on the same layer as the plurality of second pads, and a third flat layer, wherein the first routing line is arranged closer to the substrate relative to the second routing line, and the third flat layer is arranged closer to the substrate relative to the second routing line and covers the first routing line.

[0108] The first trace is electrically connected to at least one of the plurality of first pads and is used for transmitting an electrical signal provided by the circuit board.

[0109] The second routing line is used to realize the series connection or parallel connection of the plurality of second pads, and is also used to be electrically connected to the first routing line through a via hole penetrating the third planar layer.

[0110] The specific connection method of the above-mentioned multiple groups of second pads is not limited. Figure 1 The following example is used to illustrate the connection of two adjacent groups of second pads in series. Figure 1 As shown, region OA is a binding region, region OB is a light-emitting region, and a plurality of second pads can be divided into a plurality of groups of second pads, each group of second pads is used to bind a light-emitting diode, and includes a cathode pad 2' and an anode pad 2 arranged in pairs. The first routing may include an anode routing 51 and a cathode routing 52, and the second routing includes routing 81 and routing 82. Two adjacent groups of second pads are connected in series through routing 81; among the two groups of second pads in series, the anode pad of one group is connected to a routing 82, and routing 82 is electrically connected to the anode routing 51 through a via 4 penetrating the third flat layer; the anode routing 51 is connected to the cathode routing 52 through a via ( Figure 1 The cathode pad of another group is electrically connected to another trace 82, which is electrically connected to the cathode trace 52 through another via 4 penetrating the third flat layer, and the cathode trace 52 is electrically connected to the cathode trace 52 through a via ( Figure 1 The first pad 1 is electrically connected to the other first pad 1. Figure 1 In the figure, the cathode pad 2', the anode pad 2, the first pad 1, the trace 81 and the trace 82 are arranged on the same layer and use the same filling pattern; the anode trace 51 and the cathode trace 52 are arranged on the same layer and use the same filling pattern.

[0111] Of course, the light-emitting substrate may further include a third protective layer, which is located between the third flat layer and the first wiring and covers the first wiring. In this case, the second wiring needs to be electrically connected to the first wiring through a via hole penetrating the third flat layer and the third protective layer.

[0112] An embodiment of the present invention further provides a backlight module, comprising the light-emitting substrate disclosed in the above embodiment.

[0113] According to the relevant technology, the backlight module may further include a diffusion sheet, a driving circuit and other structures, which may be determined according to actual needs and will not be described in detail here.

[0114] The backlight module can be used in any display device or component that needs to provide backlight. The backlight module can be a rigid backlight module or a flexible backlight module (that is, bendable and foldable); there is no limitation here.

[0115] Compared with traditional backlight modules, when Mini-LED is used as a light source in a backlight module, an ultra-thin light source module can be made by arranging the light source more densely; combined with regional dimming technology, the display screen including the Mini-LED backlight module will have better contrast and high dynamic lighting rendering display effect. LCDs using Mini-LED backlights are far superior to current LCDs in terms of brightness, contrast, color reproduction and power consumption, and can even compete with active matrix organic light-emitting diode displays in terms of contrast and power consumption, while also being able to use existing LCD production lines to control production costs.

[0116] For the structure of the light-emitting substrate involved in this embodiment, reference may be made to the relevant descriptions about the light-emitting substrate in the above embodiments, which will not be repeated here.

[0117] An embodiment of the present invention also provides a display device, comprising the light-emitting substrate, circuit board and multiple light-emitting units disclosed in the above embodiment; the circuit board is electrically connected to multiple first pads of the light-emitting substrate, and the multiple light-emitting units are electrically connected to multiple second pads of the light-emitting substrate.

[0118] The display device has the characteristics of high contrast, good brightness, high color reproduction, etc. The display device can be a rigid display device or a flexible display device (i.e., bendable or foldable). The display device can be any product or component with a display function, such as a television, a digital camera, a mobile phone, a tablet computer, etc.

[0119] For the structure of the light-emitting substrate involved in this embodiment, reference may be made to the relevant descriptions about the light-emitting substrate in the above embodiments, which will not be repeated here.

[0120] An embodiment of the present invention further provides a method for manufacturing a display device, comprising:

[0121] S1. Forming a light-emitting substrate as disclosed in the above embodiment.

[0122] S2. Binding a plurality of light-emitting units to a plurality of second pads of the light-emitting substrate.

[0123] Specifically, if the light-emitting unit includes a light-emitting diode, the plurality of second pads are divided into a plurality of groups of second pads, and each group of second pads includes a cathode pad and an anode pad arranged in pairs, then the anode and cathode of the light-emitting diode are electrically connected to the anode pad and the cathode pad, respectively. In this step, a reflow soldering process can be used to complete the binding.

[0124] S3, bonding the circuit board and a plurality of first pads of the light-emitting substrate.

[0125] In this step, the binding can be completed by heat pressing.

[0126] An embodiment of the present invention provides a method for manufacturing a display device, in which, in the light-emitting substrate formed by step S1, the first pad in the binding area includes a first metal sublayer and a first conductive sublayer, and the first conductive sublayer is anti-oxidative and covers the first metal sublayer; then, when executing step S2, the first conductive sublayer in the binding area will not be oxidized, thereby ensuring the binding quality of the circuit board in the subsequent step S3, thereby improving the product yield.

[0127] The present invention further provides a method for manufacturing a display device. The structure of the light-emitting substrate included in the display device can refer to Figure 6 or Fig. 9 As shown, the method includes:

[0128] S11, forming a metal film and a conductive film in sequence and patterning them to obtain Figure 4 The illustrated first metal sub-layer 11 , the second metal sub-layer 21 , the first conductive sub-layer 12 located on the first metal sub-layer 11 , and the second conductive sub-layer 22 located on the second metal sub-layer 21 .

[0129] Here, the metal sublayer film and the conductive sublayer film can be deposited in one step by sputtering process, and can be patterned by etching in one step by copper etching solution to form a first metal sublayer, a first conductive sublayer, a second metal sublayer and a second conductive sublayer. In S11, a mask is required to form the desired pattern.

[0130] It should be noted that the first pad and the second pad formed by S11 include two-layer structures respectively. The materials of the first metal sublayer and the second metal sublayer include copper. In order to increase the adhesion of copper and reduce the difficulty of manufacturing, the first pad may also include a first buffer sublayer, and the first metal sublayer is located on the first buffer sublayer; the second pad may also include a second buffer sublayer, and the second metal sublayer is located on the second buffer sublayer; the first buffer sublayer and the second buffer sublayer are arranged in the same layer, and the material may be a molybdenum-containing alloy, for example: molybdenum-titanium-nickel alloy. If the first pad and the second pad also include a first buffer sublayer and a second buffer sublayer, respectively, the buffer sublayer film, the metal sublayer film and the conductive sublayer film can be deposited in one step by a sputtering process, and can be patterned by etching in one step using a copper etching solution to form a first buffer sublayer, a second buffer sublayer, a first metal sublayer, a second metal sublayer, a first conductive sublayer and a second conductive sublayer.

[0131] S12, removing the portion of the second conductive sublayer used for binding with the light-emitting unit (i.e., removing the second conductive sublayer at the location of the second pad), to obtain Figure 6 The light-emitting substrate shown.

[0132] The material of the second conductive sublayer includes indium zinc oxide or indium tin oxide. Considering that indium zinc oxide has better conductivity and lower resistivity, indium zinc oxide is generally used. Indium zinc oxide can be etched by any acidic substance. Figure 5 As shown, the mesh etching process is used to etch away the portion of the second conductive sub-layer used for binding with the light-emitting unit, thereby facilitating the subsequent use of solder paste to bind the light-emitting unit to the second metal sub-layer through a reflow soldering and die bonding process. Figure 5 In the process, the tool 40 is used to push the IZN etching paste 30 from the mask plate 20 to the area to be etched.

[0133] S13, binding the light-emitting unit and the second metal sub-layer.

[0134] Specifically, solder paste brushing, LED component bonding, reflow soldering, silicone encapsulation and other processes are performed in sequence to complete the binding of the light-emitting unit and the second metal sublayer, thereby forming a Figure 7 Since the first conductive sublayer protects the first metal sublayer, oxidation of the first metal sublayer in S13 can be avoided, thereby ensuring the binding quality of subsequent circuit boards and improving product yield.

[0135] S14, binding the circuit board and the first conductive sublayer.

[0136] Specifically, the circuit board and the first conductive sublayer may be bound together through the first connecting portion.

[0137] The manufacturing method of the light-emitting substrate is simple, easy to implement and highly operable.

[0138] Optionally, before S12, removing the portion of the second conductive sublayer used for binding with the light-emitting unit, and after S11, sequentially forming and patterning a metal film and a conductive film, the method further includes:

[0139] S15, forming an organic thin film and patterning it to obtain a first flat layer and Figure 6 As shown in the second planar layer 24 , the second planar layer is provided with a second via hole in a region corresponding to the second metal sub-layer to expose the second pad.

[0140] The materials of the first planar layer and the second planar layer may be organic materials, such as resin. In S15, a mask plate is required to form a desired pattern.

[0141] At this time, S13, binding the light-emitting unit and the second metal sublayer includes:

[0142] S131, forming a second connection portion in the second via hole, the second connection portion being electrically connected to the second metal sub-layer. The material of the second connection portion can be solder paste, copper paste, etc., and solder paste is usually used in practice.

[0143] S132. Bind the light-emitting unit onto the second connecting portion.

[0144] Specifically, a reflow soldering die bonding process may be used for bonding, wherein the reflow soldering peak temperature is about 240° C. and the holding time is 90 seconds.

[0145] Of course, after S132, in order to better protect the light-emitting unit, the light-emitting unit will be encapsulated with encapsulation materials such as silicone to form a Figure 7 The encapsulation layer shown is 9. Generally, the curing temperature of silicone is 150°C and maintained for 4 hours.

[0146] Optionally, after S13, binding the light-emitting unit and the second metal sublayer, and before S14, binding the circuit board and the first conductive sublayer, the method further includes:

[0147] Combination Figure 8 and Fig. 9 , S16, partially etching the area of ​​the first flat layer 14 corresponding to the first conductive sublayer 12 to form a first via hole to expose the first pad. It should be noted that before S16, the light-emitting area has been packaged. Since the packaging layer is relatively thick, the first via hole formed by etching in S16 has little effect on the light-emitting area, so there is no need to use an additional mask plate.

[0148] S14, binding the circuit board and the first conductive sublayer includes:

[0149] S141 . Form a first connecting portion in the first via hole, wherein the first connecting portion is electrically connected to the first conductive sublayer.

[0150] S142. Bind the circuit board onto the first connecting portion.

[0151] Here, the material of the first connection part may be a thermosetting adhesive, and the circuit board may be bound by hot pressing, and the temperature is generally 130° C. to 150° C.

[0152] It should be noted that the second via and the first via are formed respectively by S15 and S16, so that in S13, when the light-emitting unit and the second metal sublayer are bound, a first flat layer is provided above the first pad, and the first flat layer can protect the first pad and prevent it from being oxidized. Therefore, when this method is used, the first pad can also include only the first metal sublayer without the need to set the first conductive sublayer, and correspondingly, the second pad can also include only the second metal sublayer without the need to set the second conductive sublayer.

[0153] In addition, since the first pad includes the first metal sublayer and the first conductive sublayer, the first conductive sublayer plays a good protective role on the first metal sublayer, so S16 can also be incorporated into S15, that is, in S15, the first via hole and the second via hole are formed at the same time to expose the first pad and the second pad, and the formed light-emitting substrate structure can refer to Figure 6 Thus, in S13, when the light-emitting unit and the second metal sublayer are bonded, even if the first pad is exposed, the first conductive sublayer can avoid oxidation of itself and the first metal sublayer because of its good oxidation resistance.

[0154] In the manufacturing method, a mask plate is used in S11 and S15. Fig. 9 The light-emitting substrate shown in FIG. 1 further includes, before S11, forming a first wiring, the first wiring including an anode wiring 51 and a cathode wiring ( Fig. 9 Not shown). Then, forming Fig. 9 The light-emitting substrate shown requires a total of 4 masks (4Mask).

[0155] In the related art, the light-emitting substrate is formed as Fig. 20 As shown, the four-step mask manufacturing method generally includes: S100, Fig.14 As shown, a thick copper layer 101 is formed on a glass substrate 100; S101, forming Fig.15 The first resin layer (Resin-1) 102 shown in FIG. 102; S102, forming Fig.15 The thin copper layer 103 shown; S103, forming Fig.16 The silicon nitride oxide insulating layer 104 is shown; S104, forming Fig.17 The second resin layer (Resin-2) 105 shown in FIG. Fig.18 As shown in FIG. 1 , a hole is opened in the diode bonding area (LED Bonding Pad) and the flexible circuit board bonding area (FPC Bonding Pad); S105, dry etching is performed on the opening area to expose the thin copper layer, thereby forming a Fig.19 The Mini-LED light-emitting substrate shown in the figure. Then, the back-end process is carried out. The back-end process includes: brushing solder paste, transferring light-emitting diodes, reflow soldering, screen printing silicone, and silicone curing. The completed light-emitting substrate is as follows Fig. 20 As shown. The peak temperature of reflow soldering is about 240℃, and the holding time is 90s. The curing temperature of silicone is 150℃, and it is kept for 4h. These temperature processes will cause the copper surface of the binding area of ​​the flexible circuit board to turn dark red and oxidize, which will cause poor binding of the subsequent flexible circuit board and reduce the product yield. Fig. 20In the embodiment, the anode 108 and the cathode 109 of the micro light emitting diode 107 are electrically connected to the thin copper layer 103 through the solder paste 110 respectively, and the light emitting substrate also includes a silicone encapsulation layer 106.

[0156] Compared with the related art, the method for manufacturing the light-emitting substrate provided in the embodiment of the present invention does not increase the number of mask plates, and can avoid the problem of oxidation of the first metal sublayer made of copper in the process of manufacturing the light-emitting substrate, thereby ensuring the binding quality of the circuit board and improving the product yield. In addition, in the light-emitting substrate provided in the embodiment of the present invention, since a second conductive sublayer is arranged above the first metal sublayer, the second metal sublayer is well protected. Therefore, the method for manufacturing the light-emitting substrate removes the process of the silicon oxynitride protective layer in the original process, thereby eliminating the PECVD (Plasma Enhanced Chemical Vapor Deposition) process and the silicon oxynitride etching process in the original process, simplifying the original process flow and reducing the manufacturing cost.

[0157] The embodiment of the present invention also provides a method for manufacturing a display device. The structure of the light-emitting substrate included in the display device can refer to Figure 2 As shown, the method includes:

[0158] S21, forming a metal film and a conductive film in sequence and patterning them to obtain a first metal sublayer, a second metal sublayer, a first conductive sublayer located on the first metal sublayer, and a second conductive sublayer located on the second metal sublayer.

[0159] Here, the metal sublayer film and the conductive sublayer film can be deposited in one step by sputtering process, and can be patterned by etching in one step by etching solution to form the first metal sublayer, the first conductive sublayer, the second metal sublayer and the second conductive sublayer. In S21, a mask plate is required to form the required pattern.

[0160] It should be noted that the first routing layer and the second routing layer formed by S21 include two-layer structures respectively. If the materials of the first metal sublayer and the second metal sublayer include copper, in order to increase the adhesion of copper and reduce the difficulty of manufacturing, the first pad may also include a first buffer sublayer, and the first metal sublayer is located on the first buffer sublayer; the second pad may also include a second buffer sublayer, and the second metal sublayer is located on the second buffer sublayer. If the first pad and the second pad also include a first buffer sublayer and a second buffer sublayer, respectively, the buffer sublayer film, the metal sublayer film and the conductive sublayer film can be deposited in one step by a sputtering process, and the etching solution can be used for one-step etching for patterning to form a first buffer sublayer, a second buffer sublayer, a first metal sublayer, a second metal sublayer, a first conductive sublayer and a second conductive sublayer.

[0161] If the materials of the first metal sublayer and the second metal sublayer include an alloy containing molybdenum, at this time, the first soldering pad includes a two-layer structure of the first metal sublayer (molybdenum-containing alloy layer) and the first conductive sublayer (copper-nickel-containing alloy layer), and the second soldering pad includes a two-layer structure of the second metal sublayer (molybdenum-containing alloy layer) and the second conductive sublayer (copper-nickel-containing alloy layer).

[0162] S22, binding the light-emitting unit and the second conductive sublayer.

[0163] Specifically, solder paste brushing, LED mounting, reflow soldering, silicone encapsulation process, etc. can be performed in sequence to complete the binding of the light-emitting unit and the second metal sublayer. When performing S22, if the material of the first metal sublayer includes copper, the first conductive sublayer protects the first metal sublayer, thereby preventing the first metal sublayer from being oxidized; if the material of the first metal sublayer includes an alloy containing molybdenum, the material of the first conductive sublayer includes an alloy containing copper and nickel, and the first conductive sublayer has oxidation resistance and will not be oxidized. In summary, both situations can avoid the oxidation of the first wiring layer in the binding area when the light-emitting unit and the second conductive sublayer are bound in the light-emitting area; thereby ensuring the binding quality of the subsequent circuit board, and then improving the product yield.

[0164] S23, binding the circuit board and the first conductive sublayer.

[0165] Specifically, the circuit board and the first conductive sublayer may be bound together through the first connecting portion.

[0166] The manufacturing method of the light-emitting substrate is simple, easy to implement and highly operable.

[0167] Optionally, before S22, binding the light-emitting unit and the second conductive sublayer, and after S21, sequentially forming and patterning the metal film and the conductive film, the method further includes:

[0168] S24, forming a first thin film and a second thin film in sequence and patterning them to obtain a first protective layer, a second protective layer, a first flat layer, a second flat layer and a second via hole, wherein the second via hole penetrates the second protective layer and the second flat layer to expose the second pad.

[0169] The material of the first film may be silicon nitride oxide, silicon nitride, etc., for forming the first protective layer and the second protective layer; the material of the second film may be resin, for forming the first flat layer and the second flat layer. In S24, a mask plate is required to form the desired pattern.

[0170] S22, binding the light-emitting unit and the second conductive sublayer includes:

[0171] S221, forming a second connection portion in the second via hole, the second connection portion being electrically connected to the second conductive sublayer. The second connection portion may be solder paste, copper paste, etc., and solder paste is usually used in practice.

[0172] S222. Bind the light-emitting unit onto the second connecting portion.

[0173] Specifically, a reflow soldering die bonding process may be used for bonding, wherein the reflow soldering temperature is 230-260° C. and the holding time is 90 seconds.

[0174] Of course, after S222, in order to better protect the light-emitting unit, the light-emitting unit will be encapsulated with encapsulation materials such as silicone. Generally, the curing temperature of silicone is 150°C and maintained for 4 hours.

[0175] After S22, binding the light-emitting unit and the second conductive sublayer, and before S23, binding the circuit board and the first conductive sublayer, the method further includes:

[0176] S25, partially etching the first protective layer and the first flat layer in the area corresponding to the first conductive sublayer to form a first via hole to expose the first pad. It should be noted that before S25, the light-emitting area has been packaged. Since the packaging layer is relatively thick, the first via hole is etched in S25, which has little effect on the light-emitting area, so there is no need to use an additional mask plate.

[0177] S23, binding the circuit board and the first conductive sublayer includes:

[0178] S231 . Form a first connecting portion in the first via hole, wherein the first connecting portion is electrically connected to the first conductive sublayer.

[0179] S232, binding the circuit board onto the first connecting portion.

[0180] Here, the first connection part may be a thermosetting adhesive, and the circuit board may be bound by hot pressing, and the temperature is generally 130° C. to 150° C.

[0181] It should be noted that the second via and the first via are formed respectively by S24 and S25, so that in S22, when the light-emitting unit and the second metal sublayer are bound, a first protective layer and a first flat layer are provided above the first pad, and the first protective layer and the first flat layer can protect the first pad and prevent it from being oxidized. Therefore, when this method is used, the first pad can also include only a copper sublayer or a copper-containing alloy sublayer, without the need to provide a two-layer conductive structure, and accordingly, the second pad can also include only a copper sublayer or a copper-containing alloy sublayer.

[0182] In addition, since the first pad includes the first metal sublayer and the first conductive sublayer, and the first conductive sublayer plays a good protective role on the first metal sublayer, S25 can also be incorporated into S24, that is, in S24, the first via hole and the second via hole are formed at the same time to expose the first pad and the second pad. In this way, when S22 is used to bind the light-emitting unit and the second metal sublayer, even if a part of the first pad is exposed due to the first via hole, the first conductive sublayer has good oxidation resistance, so that the first pad and the first metal sublayer can be prevented from being oxidized.

[0183] In the manufacturing method, a mask plate is used in each of S21 and S24. Figure 2 The light-emitting substrate shown in FIG. 1 further comprises, before step S21, forming a first wiring, a third protective layer 34 and a third flat layer 33 respectively, wherein the first wiring comprises an anode wiring 51 and a cathode wiring ( Figure 2 (not shown). To form the third wiring, a mask plate is required, and to form the third protection layer 33 and the third flat layer 34, a mask plate is required. Figure 2 The light-emitting substrate shown requires a total of 4 masks (4Mask).

[0184] Compared with the related art, the method for manufacturing the light-emitting substrate provided in the embodiment of the present invention does not increase the number of mask plates, and can avoid the problem of oxidation of the first metal sublayer made of copper in the process of manufacturing the light-emitting substrate, thereby ensuring the binding quality of the circuit board and further improving the product yield.

[0185] The embodiment of the present invention further provides a method for manufacturing a display device. The structure of the light-emitting substrate included in the display device can refer to Fig.13 As shown, the method includes:

[0186] S31, forming a peeling layer on the substrate, wherein the peeling layer is located in the binding area and the light emitting area.

[0187] The material of the peeling layer can be a mechanically peelable material. The material of the substrate can be a rigid material, such as glass, or a flexible material, such as polyimide (PI).

[0188] S32, forming a first pad 1 and a second pad (cathode pad 2' and anode pad 2) on the peeling layer; the first pad includes a first metal sublayer and a first conductive sublayer stacked. The formed light-emitting substrate can refer to Fig.10 shown.

[0189] Before proceeding with the binding process, refer to Fig.11 As shown, a local laser lift-off (LLO) process and light-emitting substrate cutting are completed at the circuit binding board position to obtain a single light-emitting substrate to be bound, and then a subsequent binding process is performed on the single light-emitting substrate to be bound.

[0190] S33, binding the light emitting unit and the second pad.

[0191] Specifically, solder paste brushing, light emitting diode mounting, reflow soldering, silicone encapsulation and the like can be performed in sequence to complete the binding of the light emitting unit and the second wiring layer.

[0192] S34, removing at least the area of ​​the substrate and the peeling layer corresponding to the portion of the first metal sub-layer used for binding the circuit board ( Fig.12 Marked 50 in the figure), and partially exposing the first metal sublayer.

[0193] Specifically, local cutting may be used to remove the area in the substrate and the peeling layer corresponding to the portion of the first metal sub-layer used for binding the circuit board.

[0194] S35 , bonding the circuit board and the first metal sub-layer.

[0195] Specifically, the circuit board and the first metal sub-layer may be bound together through the first connecting portion.

[0196] In this method, the first pad formed includes a first metal sublayer and a first conductive sublayer. Then, when the light-emitting unit and the second metal sublayer are bound, the first pad in the binding area will not be oxidized, thereby ensuring the binding quality of the subsequent circuit board and the first conductive sublayer, thereby improving the product yield. In addition, in this method, the circuit board is bound to the side of the first metal sublayer close to the peeling layer, thereby reducing the non-luminous area of ​​the light-emitting side, thereby achieving a narrower frame.

[0197] Further optional, refer to Fig.13 As shown, the light-emitting substrate further includes a first organic layer 41, a protective layer 43, a second organic layer 42, a via ( Fig.13 The first organic layer covers the first pad. The second pad is located above the first organic layer, the protective layer covers the second pad and the first organic layer, and the second organic layer is located above the protective layer. The via penetrates the second organic layer and the protective layer to expose the second pad, and the light-emitting unit is electrically connected to the second pad through the second connecting portion.

[0198] Then, the step of forming the first pad on the peeling layer requires a mask plate; in addition, forming the second pad, forming the first organic layer, forming the protective layer, the second organic layer and the via hole requires a mask plate respectively. Fig.13The light-emitting substrate shown requires a total of 4 mask plates. Compared with the related art, the number of mask plates is not increased, and the problem of oxidation of the first pad during the production of the light-emitting substrate can be avoided, thereby ensuring the binding quality of the circuit board and improving the product yield. In addition, in this method, the circuit board is bound to the side of the first metal sublayer close to the peeling layer, thereby reducing the non-luminous area on the light-emitting side, thereby achieving a narrower frame.

[0199] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A light-emitting substrate, comprising a binding area and a light-emitting area, characterized in that: The binding area includes a plurality of first pads, and the plurality of first pads are used for binding and connecting with the circuit board; any one of the plurality of first pads includes a first metal sublayer and a first conductive sublayer which are stacked; the material of the first metal sublayer includes a metal or a metal alloy; the first conductive sublayer has oxidation resistance and covers the first metal sublayer; The light-emitting area includes a plurality of second pads, and the plurality of second pads are used for binding and connecting with a plurality of light-emitting units; The light-emitting substrate further includes a substrate. The first conductive sublayer is located on a side away from the substrate relative to the first metal sublayer. The material of the first conductive sublayer includes metal oxide or metal alloy.

2. The light-emitting substrate according to claim 1, characterized in that: The material of the first metal sub-layer includes copper, and the material of the first conductive sub-layer includes indium zinc oxide or indium tin oxide.

3. The light-emitting substrate according to claim 2, characterized in that: Any one of the plurality of second pads includes a second metal sublayer, and the second metal sublayer is disposed in the same layer as the first metal sublayer.

4. The light-emitting substrate according to claim 3, characterized in that: The binding area further includes a first connection portion and a first flat layer, the first connection portion is located at a side away from the substrate relative to the first conductive sublayer, and the first flat layer covers the area between the plurality of first pads; The light emitting area further includes a second connecting portion and a second planar layer, the second connecting portion is located at a side away from the substrate relative to the second metal sublayer, and the second planar layer covers the area between the plurality of second pads; Wherein, the first planar layer and the second planar layer are arranged on the same layer.

5. The light-emitting substrate according to claim 1, characterized in that: The material of the first metal sub-layer includes copper or an alloy containing molybdenum, and the material of the first conductive sub-layer includes an alloy containing copper and nickel.

6. The light-emitting substrate according to claim 5, characterized in that: Any one of the multiple second pads includes a second metal sublayer and a second conductive sublayer that are stacked, and the second conductive sublayer is located on a side away from the substrate relative to the second metal sublayer; wherein the second metal sublayer is arranged on the same layer as the first metal sublayer, and the second conductive sublayer is arranged on the same layer as the first conductive sublayer.

7. The light-emitting substrate according to claim 6, characterized in that: The binding area further includes a first connection portion, and a first protection layer and a first flat layer which are stacked, wherein the first connection portion is located on a side of the first conductive sublayer away from the substrate, and the first flat layer is located on a side of the first protection layer away from the substrate and covers an area between the plurality of first pads; The light-emitting area further includes a second connection portion, and a second protection layer and a second flat layer which are stacked, wherein the second connection portion is located on a side of the second conductive sublayer away from the substrate, the second protection layer covers an area between the plurality of second pads, and the second flat layer is located on a side of the second protection layer away from the substrate; The first protection layer and the second protection layer are arranged on the same layer, and the first planarization layer and the second planarization layer are arranged on the same layer.

8. The light emitting substrate according to claim 1, characterized in that: The light-emitting substrate further comprises a substrate; The plurality of first solder pads are exposed facing the surface of the substrate for binding the circuit board; the plurality of second solder pads are exposed away from the surface of the substrate for binding the light emitting unit.

9. The light-emitting substrate according to claim 1, characterized in that: The plurality of second pads are divided into a plurality of groups of second pads, each group of the second pads comprising a cathode pad and an anode pad arranged in pairs; The light-emitting substrate further includes a substrate, a first routing line, a second routing line arranged on the same layer as the plurality of second pads, and a third flat layer, wherein the first routing line is arranged close to the substrate relative to the second routing line, and the third flat layer is arranged close to the substrate relative to the second routing line and covers the first routing line; The first trace is electrically connected to at least one of the plurality of first pads, and is used to transmit an electrical signal provided by the circuit board; The second routing line is used to realize series connection or parallel connection of multiple groups of the second pads, and is also used to be electrically connected to the first routing line through a via hole penetrating the third planar layer.

10. A display device, characterized in that: A light-emitting substrate, a circuit board and a plurality of light-emitting units according to any one of claims 1 to 9; The circuit board is electrically connected to a plurality of first pads of the light emitting substrate, and the plurality of light emitting units are electrically connected to a plurality of second pads of the light emitting substrate.

11. A method for manufacturing a display device according to claim 10, characterized in that: include: Forming a light-emitting substrate as described in any one of claims 1 to 9; Binding a plurality of light-emitting units to a plurality of second pads of the light-emitting substrate; A plurality of first solder pads are bonded to the circuit board and the light emitting substrate.

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