Light-emitting substrate and display device

Abstract

The present invention discloses a light-emitting substrate and a display device. In the light-emitting substrate, a first solder pad in a light-emitting area includes a first metal layer located on a base substrate and a second metal layer located on a side of the first metal layer away from the base substrate. The material of the second metal layer includes a copper-nickel-titanium alloy. Since nickel and titanium are resistant to oxidation, the present invention designs the number of nickel atoms and / or titanium atoms contained per unit area in a cross-section farther from the base substrate to be greater than the number of nickel atoms and / or titanium atoms contained per unit area in another cross-section closer to the base substrate. In this way, the number of nickel atoms and / or titanium atoms in the surface of the second metal layer farther from the base substrate is greater, thereby making the surface of the second metal layer resistant to oxidation. Therefore, during the production process of the light-emitting substrate, the second metal layer in the light-emitting area will not be oxidized, thereby avoiding the problem of oxidation during the production process of the 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 and a display device. Background Art

[0002] Mini / Micro LED light-emitting substrates have high requirements for the resistance of metal traces, so copper is often used as the wiring material. During the light-emitting substrate production process, Mini / Micro LED bonding, flexible printed circuit board (FPCB) bonding, or integrated circuit bonding are required. Summary of the invention

[0003] Embodiments of the present invention provide a light-emitting substrate and a display device, which can avoid the problem of oxidation of the pads in the light-emitting area, thereby ensuring reliable electrical connection between the light-emitting unit and the light-emitting substrate, and further improving product yield.

[0004] Therefore, an embodiment of the present invention provides a light-emitting substrate, comprising a base substrate, the base substrate having a light-emitting area, the light-emitting area comprising a plurality of first pads located on the base substrate, the plurality of first pads being used for binding and connecting with a plurality of light-emitting units;

[0005] Any one of the plurality of first pads comprises: a first metal layer located on the base substrate, and a second metal layer located on a side of the first metal layer facing away from the base substrate;

[0006] The material of the first metal layer includes copper, and the material of the second metal layer includes copper-nickel-titanium alloy;

[0007] In at least two cross-sections of the second metal layer parallel to the plane of the substrate, the number of nickel atoms per unit area in a cross-section farther from the substrate is greater than the number of nickel atoms per unit area in another cross-section closer to the substrate;

[0008] And / or, the number of titanium atoms contained per unit area in the cross section farther from the substrate is greater than the number of titanium atoms contained per unit area in the other cross section closer to the substrate.

[0009] Optionally, in the above-mentioned light-emitting substrate provided by an embodiment of the present invention, the thickness of the second metal layer is 30 nm-100 nm.

[0010] Optionally, in the above-mentioned light-emitting substrate provided by an embodiment of the present invention, in the material of the second metal layer, the mass fraction of Cu accounts for 90% to 95%, the mass fraction of Ni accounts for 4.5% to 9%, and the mass fraction of Ti accounts for 0.5% to 1%.

[0011] Optionally, in the above-mentioned light-emitting substrate provided by the embodiments of the present invention, the material of the second metal layer further includes Si or C or O, and the mass fraction of any one of the Si, the C, and the O is less than 0.1%.

[0012] Optionally, in the above-mentioned light-emitting substrate provided by the embodiments of the present invention, the substrate further has a bonding area, and the bonding area includes a plurality of second pads located on the substrate, and the plurality of second pads are used for bonding connection with a circuit board; any one of the plurality of second pads includes: a third metal layer located on the substrate, and a fourth metal layer located on a side of the third metal layer away from the substrate; wherein,

[0013] The third metal layer and the first metal layer are arranged in the same layer, and the fourth metal layer and the second metal layer are arranged in the same layer.

[0014] Optionally, in the above-mentioned light-emitting substrate provided by the embodiments of the present invention, it further includes a first wiring layer located between the first pad and the substrate, and the first wiring layer includes a first metal sub-layer, a first wiring sub-layer, and a second metal sub-layer that are stacked; wherein,

[0015] The first metal layer is electrically connected to the second metal sub-layer, and the third metal layer is electrically connected to the second metal sub-layer;

[0016] The materials of the first metal sub-layer and the second metal sub-layer include molybdenum niobium alloy, and the material of the first wiring sub-layer includes copper.

[0017] Optionally, in the above-mentioned light-emitting substrate provided by the embodiments of the present invention, the light-emitting area further includes: a first passivation layer located between the first wiring layer and the first metal layer, a first planarization layer located between the first passivation layer and the first metal layer, a second planarization layer located on a side of the second metal layer away from the substrate, and a first connection portion located on the second metal layer; the second planarization layer covers the area between the plurality of first pads.

[0018] Optionally, in the above-mentioned light-emitting substrate provided by the embodiments of the present invention, the bonding area further includes: a second passivation layer located between the first wiring layer and the third metal layer, a third planarization layer located between the second passivation layer and the third metal layer, a fourth planarization layer located on a side of the fourth metal layer away from the substrate, and a second connection portion located on the fourth metal layer; wherein,

[0019] The fourth planarization layer covers the area between the plurality of second pads;

[0020] The third flat layer is arranged on the same layer as the first flat layer, the fourth flat layer is arranged on the same layer as the second flat layer, and the second passivation layer is arranged on the same layer as the first passivation layer.

[0021] Optionally, in the above-mentioned light-emitting substrate provided by the embodiment of the present invention, the plurality of first pads are divided into multiple groups of first pads, and each group of the first pads includes a cathode pad and an anode pad arranged in pairs;

[0022] The light-emitting substrate further includes a second wiring layer arranged on the same layer as the plurality of first pads. The second wiring layer is used to realize the series connection or parallel connection of multiple groups of the first pads, and is also used to be electrically connected to the first wiring layer through vias penetrating the first flat layer and the first passivation layer.

[0023] Optionally, in the above-mentioned light-emitting substrate provided by the embodiment of the present invention, a protective layer is further included on the side of the first pads and the second pads facing away from the substrate. The protective layer exposes the first pads and the second pads, and the material of the protective layer includes silicon nitride or silicon oxide.

[0024] Correspondingly, the embodiment of the present invention further provides a display device, including: the above-mentioned light-emitting substrate provided by the embodiment of the present invention, a circuit board, and a plurality of light-emitting units;

[0025] The plurality of light-emitting units are electrically connected to the plurality of first pads of the light-emitting substrate, and the circuit board is electrically connected to the plurality of second pads of the light-emitting substrate.

[0026] Optionally, in the above-mentioned display device provided by the embodiment of the present invention, the light-emitting unit is a MiniLED or a Micro LED.

[0027] The beneficial effects of the present invention are as follows:

[0028] The light-emitting substrate and display device provided by an embodiment of the present invention include a first pad in the light-emitting area of the light-emitting substrate including a first metal layer located on a base substrate and a second metal layer located on a side of the first metal layer facing away from the base substrate. The material of the second metal layer includes a copper-nickel-titanium alloy. Since nickel and titanium are resistant to oxidation, the present invention designs the number of nickel atoms and / or titanium atoms contained per unit area in a cross-section further away from the base substrate to be greater than the number of nickel atoms and / or titanium atoms contained per unit area in another cross-section closer to the base substrate. This allows the number of nickel atoms and / or titanium atoms on the surface of the second metal layer away from the base substrate to be greater, thereby making the surface of the second metal layer resistant to oxidation. Therefore, during the manufacturing process of the light-emitting substrate, the second metal layer in the light-emitting area will not oxidize, thereby avoiding the problem of oxidation during the manufacturing process of the light-emitting substrate. The second metal layer can thus protect the first metal layer and avoid oxidation of the first metal layer during the manufacturing process of the light-emitting substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 For the Figure 2 A schematic cross-sectional view of the AA' direction;

[0030] Figure 2 A schematic top view of a light-emitting substrate provided by an embodiment of the present invention;

[0031] Figure 3 For the Figure 2 Another cross-sectional schematic diagram along the AA' direction. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present invention clearer, the specific implementation methods of the light-emitting substrate and its preparation method, the light-emitting substrate light-emitting device, and related devices provided in the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0033] The thickness and shape of each film layer in the drawings do not reflect the actual proportion of the light-emitting substrate, and are only intended to illustrate the content of the present invention.

[0034] Mini-LED (sub-millimeter light-emitting diode) refers to a light-emitting diode with a size between 80 and 300 um. When Mini-LED is used as the pixel points of a 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, a thinner light source module can be made through a more dense light source arrangement; combined with local dimming technology, the display screen including the Mini-LED backlight module will have better contrast and high dynamic range (HDR) display effects. Micro-LED micro light-emitting diodes with a size less than 80 um can be directly used as the pixel points of display panels such as near-eye, wearable, and handheld terminals.

[0035] The light-emitting substrate provided by the present invention can refer to a substrate for providing a light source or a substrate for display, and there is no limitation thereto.

[0036] In related technologies, in order to complete the bonding of Mini / Micro LED to the light-emitting substrate, solder paste needs to be set on the pads of the light-emitting substrate to be electrically connected to the Mini / Micro LED. Then, the Mini / Micro LED is transferred to the corresponding position on the light-emitting substrate, and then the fixation of the Mini / Micro LED to the light-emitting substrate is completed by reflow soldering within the temperature range of 230 °C - 260 °C. The circuit board is bonded to the pads of the light-emitting substrate to be electrically connected to the circuit board, and is realized by hot pressing within the temperature range of 130 °C - 150 °C.

[0037] Since different process conditions are required to bond the Mini / Micro LED and the circuit board to the light-emitting substrate, and the bonding of the two cannot be achieved synchronously. Therefore, for example, in the case of bonding the Mini / Micro LED first, the pad material of the light-emitting substrate to be bonded to the circuit board is extremely prone to oxidation under the process conditions corresponding to the bonding of the Mini / Micro LED, which further leads to the inability to ensure good electrical connection between the circuit board and the light-emitting substrate, thereby reducing the product yield. It can be understood that the same problem will also exist if the light-emitting substrate is first bonded to the circuit board and then to the Mini / Micro LED.

[0038] An embodiment of the present invention provides a light-emitting substrate, which can be configured to be used for display or providing backlight. As Figure 1 shown, the light-emitting substrate includes a substrate 1, the substrate 1 has a light-emitting area A1, and the light-emitting area A1 includes a plurality of first pads (2 and 2') located on the substrate 1, and the plurality of first pads (2 and 2') are used for bonding connection with a plurality of light-emitting units ( Figure 1 not shown);

[0039] Any one of the plurality of first pads (2 and 2') includes: a first metal layer 21 located on the substrate 1, and a second metal layer 22 located on the side of the first metal layer 21 away from the substrate 1;

[0040] The material of the first metal layer 21 includes copper, and the material of the second metal layer 22 includes copper-nickel-titanium alloy (CuNiTi);

[0041] Among at least two cross-sections of the second metal layer 22 parallel to the plane of the substrate 1 (such as cross-section 221 and cross-section 222), the number of nickel atoms per unit area in the cross-section 222 that is farther from the substrate 1 is more than the number of nickel atoms per unit area in the cross-section 221 that is closer to the substrate 1;

[0042] And / or, the number of titanium atoms per unit area in the cross-section 222 that is farther from the substrate 1 is more than the number of titanium atoms per unit area in the cross-section 221 that is closer to the substrate 1.

[0043] In the light-emitting substrate provided by the embodiment of the present invention, in this light-emitting substrate, the first pad of the light-emitting region A1 includes a first metal layer 21 located above the substrate 1 and a second metal layer 22 located on the side of the first metal layer 21 away from the substrate 1. The material of the second metal layer 22 includes copper-nickel-titanium alloy. Since nickel and titanium have better oxidation resistance, in the embodiment of the present invention, the number of nickel atoms and / or titanium atoms per unit area in a cross-section (such as cross-section 222) of the second metal layer 22 that is farther from the substrate 1 is designed to be more than the number of nickel atoms and / or titanium atoms per unit area in another cross-section (such as cross-section 221) that is closer to the substrate 1. In this way, the number of nickel atoms and / or titanium atoms on the surface of the second metal layer 22 that is away from the substrate 1 can be made larger, so that the surface of the second metal layer 22 has oxidation resistance, thereby avoiding the problem of oxidation during the production of the light-emitting substrate. Thus, the second metal layer 22 can play a role in protecting the first metal layer 21 and prevent the first metal layer 21 from being oxidized during the production of the light-emitting substrate.

[0044] The light-emitting substrate provided by the embodiment of the present invention can be a display substrate or a backlight substrate. If it is a display substrate, the light-emitting region A1 constitutes a display region, and the light-emitting unit is a sub-pixel, thereby realizing a display screen. If it is a backlight substrate, the light-emitting region A1 is used to provide a light source to cooperate with a passive display panel to achieve display.

[0045] There is no limitation on the emission color of the light-emitting regions included in the light-emitting substrate; the light-emitting regions can be any one of a red light-emitting region, a green light-emitting region, or a blue light-emitting region. The light-emitting substrate can simultaneously include light-emitting regions of three emission colors, namely, a red light-emitting region, a green light-emitting region, and a blue light-emitting region; of course, it can also include only light-emitting regions of one emission color. For example, it can include only a plurality of red light-emitting regions, or only a plurality of green light-emitting regions, or only a plurality of blue light-emitting regions. Specifically, it can be determined according to actual requirements.

[0046] There is no limitation on the control method of the plurality of light-emitting regions. Exemplarily, each light-emitting region can be independently controlled, or a plurality of light-emitting regions can be controlled simultaneously, etc.

[0047] Specifically, the material of the substrate can be a rigid material, such as glass; or a flexible material, such as polyimide.

[0048] In specific implementation, in the above-mentioned light-emitting substrate provided by the embodiments of the present invention, as Figure 1 shown, the second metal layer 22 mainly serves to protect the first metal layer 21. Therefore, the thickness of the second metal layer 22 cannot be too thick to avoid increasing the etching difficulty and thus unable to ensure the pattern topography, nor can it be too thin, otherwise the antioxidant performance is poor. Therefore, considering the two factors of process implementation and antioxidant performance, the embodiments of the present invention set the thickness of the second metal layer 22 to be 30 nm - 100 nm, and the thickness of the first metal layer 21 is approximately in the range of several thousand angstroms.

[0049] In specific implementation, in order to ensure the conductivity and low resistance of the second metal layer, it is required that the content of Cu included in the second metal layer is relatively high. Therefore, in the above-mentioned light-emitting substrate provided by the embodiments of the present invention, as Figure 1 shown, in the material of the second metal layer 22, the mass fraction of Cu accounts for 90% - 95%, the mass fraction of Ni accounts for 4.5% - 9%, and the mass fraction of Ti accounts for 0.5% - 1%. The inventors have found through testing that when the mass fraction of Ni accounts for 4.5% - 9% and the mass fraction of Ti accounts for 0.5% - 1%, the second metal layer 22 has good antioxidant performance.

[0050] In specific implementation, in the above-mentioned light-emitting substrate provided by the embodiments of the present invention, as Figure 1 shown, there may be some impurities in the material of the second metal layer 22. For example, the material of the second metal layer 22 may also include Si or C or O, and the mass fraction of any one of Si, C, and O is less than 0.1%.

[0051] In specific implementation, in the above-mentioned light-emitting substrate provided by the embodiments of the present invention, as Figure 1As shown, the substrate 1 further has a bonding region A2, and the bonding region A2 includes a plurality of second pads 4 located on the substrate 1. The plurality of second pads 4 are used for bonding connection with a circuit board ( Figure 1 not shown); any one of the plurality of second pads 4 includes: a third metal layer 41 located on the substrate 1, and a fourth metal layer 42 located on the side of the third metal layer 41 away from the substrate 1; wherein,

[0052] The third metal layer 41 and the first metal layer 21 are arranged in the same layer, and the fourth metal layer 42 and the second metal layer 22 are arranged in the same layer. Arranging in the same layer means fabricating by a single patterning process. The single patterning process refers to forming the required pattern through a single film-forming and photolithography process. The single patterning process includes processes such as film-forming, exposure, development, etching, and stripping. The third metal layer 41 and the first metal layer 21 are arranged in the same layer, and the fourth metal layer 42 and the second metal layer 22 are arranged in the same layer, thereby reducing the number of patterning processes, simplifying the manufacturing process, and significantly reducing the production cost. And since the second metal layer 22 has antioxidant properties, the surface of the fourth metal layer 42 also has antioxidant properties; therefore, during the fabrication process of the light-emitting substrate, the fourth metal layer 42 in the bonding region does not oxidize, thereby avoiding the oxidation problem during the fabrication of the light-emitting substrate. Thus, the fourth metal layer 42 can protect the third metal layer 41 and prevent the third metal layer 41 from oxidizing during the fabrication of the light-emitting substrate.

[0053] In a specific implementation, in the above-mentioned light-emitting substrate provided by the embodiment of the present invention, as Figure 1 shown, it further includes a first wiring layer 3 located between the first pads (2 and 2') and the substrate 1. The first wiring layer 3 includes a first metal sub-layer 31, a first wiring sub-layer 32, and a second metal sub-layer 33 arranged in a stacked manner; wherein,

[0054] The first metal layer 21 is electrically connected to the second metal sub-layer 33, and the third metal layer 41 is electrically connected to the second metal sub-layer 33 for transmitting the electrical signal provided by the circuit board;

[0055] The materials of the first metal sub-layer 31 and the second metal sub-layer 33 include a molybdenum niobium alloy, which has adhesiveness and enhances the adhesion between the first wiring layer 3 and the substrate 1. In some cases, in order to prevent the overall area of the first wiring layer 3 from being too large, which may cause excessive stress on the substrate and result in fragmentation, a buffer layer can be provided between the substrate 1 and the first wiring layer 3 to relieve the stress. In addition, the first metal sub-layer 31 with a material including a molybdenum niobium alloy can also enhance the adhesion between the first wiring layer 3 and the buffer layer. The material of the buffer layer is, for example, silicon nitride. At the same time, the second metal sub-layer 33 with a material including a molybdenum niobium alloy is connected to the first pad. Since the molybdenum niobium alloy has adhesiveness, it can ensure a firm connection between the first wiring layer 3 and the first pad, and since the molybdenum niobium alloy has conductivity, it can ensure the conductivity between the first pad and the first wiring layer 3. In addition, the second metal sub-layer 33 with a material including a molybdenum niobium alloy can protect the copper of the first wiring sub-layer 32 from being oxidized. The material of the first wiring sub-layer 32 can include copper, which has good conductivity, can ensure electrical connection between film layers, has a small resistance to reduce current loss during operation, and has a low price, which can reduce the manufacturing cost of the light-emitting substrate.

[0056] In a specific implementation, as Figure 1 shown, the second pad 4 takes the example of including only the third metal layer 41 and the fourth metal layer 42. Of course, the second pad 4 can also be arranged on the same layer as the first wiring layer 3, or the second pad 4 can simultaneously include a film layer arranged on the same layer as the first wiring layer 3 and the third metal layer 41 and the fourth metal layer 42.

[0057] In a specific implementation, in the above-mentioned light-emitting substrate provided by the embodiment of the present invention, as Figure 1 shown, the light-emitting area A1 further includes: a first passivation layer 5 located between the first wiring layer 3 and the first metal layer 21, a first planarization layer 6 located between the first passivation layer 5 and the first metal layer 21, a second planarization layer 7 located on the side of the second metal layer 22 away from the substrate 1, and a first connection portion 01 located on the second metal layer 22. The second planarization layer 7 covers the area between multiple first pads (2 and 2'); wherein,

[0058] the first wiring layer 3 can include an anode wiring 34 and a cathode wiring 35 ( Figure 1(not shown), that is, the anode trace 34 and the cathode trace 35 are both provided with a stacked first metal sublayer 31, a first trace sublayer 32, and a second metal sublayer 33. In order to reduce the voltage drop (IR Drop), the thickness of the first trace sublayer 32 can be between 1μm and 7μm. The specific thickness is related to the product size of the Mini-LED backplane. In theory, the larger the size, the greater the required thickness. The first metal sublayer 31, the first trace sublayer 32, and the second metal sublayer 33 can be sequentially manufactured by a sputtering process. The second metal sublayer 33 can protect the first trace sublayer 32 and prevent the surface of the first trace sublayer 32 from oxidation. The thickness of the first metal sublayer 31 and the second metal sublayer 33 is approximately in the range of several hundred angstroms.

[0059] In specific implementation, Figure 1 As shown, the first passivation layer 5 covers the gap area between the anode wiring 34 and the cathode wiring 35, and separates adjacent wirings to avoid incorrect electrical connection between adjacent wirings. The material of the first passivation layer 5 can be silicon nitride, silicon oxide, silicon oxynitride, etc. The first flat layer 6 covers the area between the anode wiring 34 and the cathode wiring 35. The first flat layer 6 can be an organic film, which is used to fill the gap area between the wirings to avoid large step differences in subsequent processes and ensure that the light-emitting unit will not be displaced when the light-emitting unit is bound, thereby improving the flatness of the light-emitting substrate and increasing the reflectivity of the light-emitting substrate; at the same time, the first flat layer 6 can also play an insulating role.

[0060] Specifically, if Figure 1 As shown, the material of the first connection portion 01 on the second metal layer 22 can be solder paste, copper paste, etc.

[0061] In a specific implementation, in the above-mentioned light-emitting substrate provided in the embodiment of the present invention, as Figure 1 As shown, the binding area A2 further includes: a second passivation layer 8 located between the first wiring layer 3 and the third metal layer 41, a third flat layer 9 located between the second passivation layer 8 and the third metal layer 41, a fourth flat layer 10 located on the side of the fourth metal layer 42 facing away from the substrate 1, and a second connection portion 02 located on the fourth metal layer 42; wherein,

[0062] The fourth planar layer 10 covers the areas between the plurality of second pads 4;

[0063] The third planarization layer 9 is provided on the same layer as the first planarization layer 6 to form an integral structure. The material thereof may be an organic material, such as a resin, for planarization to facilitate subsequent processes. The fourth planarization layer 10 is provided on the same layer as the second planarization layer 7 to form an integral structure. The material thereof may be an organic material, such as a resin, for planarization to facilitate subsequent processes. The second passivation layer 9 is provided on the same layer as the first passivation layer 5 to form an integral structure. The material thereof may be silicon oxynitride, silicon nitride, or the like.

[0064] Specifically, as Figure 1 shown, the material of the second connection portion 02 on the fourth metal layer 42 can be a thermosetting adhesive.

[0065] In a specific implementation, in the above-mentioned light-emitting substrate provided by the embodiments of the present invention, as Figure 2 shown, the multiple first pads (2 and 2') are divided into multiple groups of first pads, and each group of first pads includes a pair of cathode pads 2' and anode pads 2 arranged in pairs;

[0066] The light-emitting substrate further includes a second wiring layer disposed on the same layer as the multiple first pads (2 and 2'), and the second wiring layer is used to realize the series connection or parallel connection of the multiple groups of first pads, and the second wiring layer is also electrically connected to the first wiring layer 3 through vias penetrating the first planar layer 6 and the first passivation layer 5.

[0067] Specifically, as Figure 1 and Figure 2 shown, Figure 1 is Figure 2 a schematic cross-sectional view along the AA' direction in Figure 1 shown, the second wiring layer includes traces 11 and 12. As Figure 1 shown, the trace 12 can include a fifth metal layer 121 and a sixth metal layer 122. The fifth metal layer 121 is electrically connected to the first metal layer 21, and the sixth metal layer 122 is electrically connected to the second metal layer 22,

[0068] Of course, in a specific implementation, Figure 1 the trace 12 in Figure 1 can also be only provided with the five-metal layer 121, that is, the

[0069] sixth metal layer 122 in Figure 3 is removed. Figure 3The light-emitting diode 100 shown. It should be noted that since the light-emitting diode 100 includes an anode and a cathode, one light-emitting diode 100 needs to be bonded through two first pads. The above-mentioned multiple first pads can be divided into multiple groups of first pads, and each group of first pads is used to bond one light-emitting diode and includes a pair of cathode pads and anode pads. The first pad bonded to the cathode of the light-emitting diode is called the cathode pad, and the first pad bonded to the anode of the light-emitting diode is called the anode pad. The light-emitting diode 100 is bonded to the cathode pad and the anode pad through the first connecting portion 01 (solder paste or copper paste). In the drawings of the embodiments of the present invention, in order to clearly distinguish the cathode pad and the anode pad, different marks are used for illustration. Specifically, refer to Figure 2 and Figure 3 shown, the cathode pad is marked as 2', and the anode pad is marked as 2, but the film layer structures included in both are the same.

[0070] The specific connection method of the above-mentioned multiple groups of first pads is not limited. Figure 2 In Figure 2 shown, taking the series connection of adjacent two groups of first pads as an example for illustration. As Figure 1 and Figure 2 shown, in the two groups of first pads connected in series, the anode pad 34 of one group is connected to a trace 12, and the trace 12 is electrically connected to the anode trace 34 through a via 03 passing through the first passivation layer 5 and the first planarization layer 6; the anode trace 34 is electrically connected to a second pad 4 through a via ( Figure 1 not shown) passing through the first passivation layer 5 and the first planarization layer 6; the cathode pad of the other group is connected to another trace 12, and this trace 12 is electrically connected to the cathode trace 35 through another via 03 passing through the first passivation layer 5 and the first planarization layer 6, and the cathode trace 35 is electrically connected to another second pad 4 through a via ( Figure 1 not shown) passing through the first passivation layer 5 and the first planarization layer 6. Figure 2 In

[0071] In specific implementation, in the above-mentioned light-emitting substrate provided by the embodiments of the present invention, as Figure 3As shown, the light-emitting substrate may further include a circuit board 200 , and the circuit board 200 is bound and connected to the second pad 4 via a second connecting portion 02 (thermosetting adhesive).

[0072] It is understandable that the present invention does not limit the driving method of the light emitting substrate. Figure 2 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.

[0073] Specifically, when a microchip provides signals to the light-emitting units, the multiple light-emitting units can be divided into multiple light zones, each of which includes at least one light-emitting unit. Each microchip is used to drive the light-emitting units in at least one light zone to emit light. Each microchip includes multiple pins, and the light-emitting substrate also includes a third pad located in the light-emitting zone. The structure of the third pad is similar to that of the first pad and can be manufactured using the same film layer structure as the first pad.

[0074] In a specific implementation, in the above-mentioned light-emitting substrate provided in the embodiment of the present invention, as Figure 1 As shown, a protective layer 13 may also be included on the side of the first pad (2 and 2') and the second pad 4 facing away from the substrate 1, the protective layer 13 exposes (2 and 2') and the second pad 4, and the material of the protective layer 13 may include silicon nitride or silicon oxide.

[0075] In a specific implementation, in the above-mentioned display device provided in an embodiment of the present invention, the light-emitting unit can be a mini light-emitting diode (English: Mini Light Emitting Diode, abbreviated as: MiniLED), also known as a sub-millimeter light-emitting diode, or a micro light-emitting diode (English: Micro Light Emitting Diode, abbreviated as: Micro LED).

[0076] When the light-emitting substrate provided by the embodiments of the present invention serves as a backlight source, Mini LED backlighting utilizes a large number of ultra-small LED light groups to achieve the backlighting effect. Mini LEDs have a small size and pitch. This allows for a more precise number of local dimming zones, achieving high-dynamic range (HDR) and high-contrast effects, while also shortening the optical distance (OD) to reduce the thickness of the entire device, meeting thinness requirements. Micro LED is a new generation display technology that miniaturizes and matrixes LEDs. Compared to Mini LEDs, it is smaller in size, which means it can further increase the number of local dimming zones and improve the contrast of LCDs.

[0077] Based on the same inventive concept, an embodiment of the present invention further provides a display device, comprising: the above-mentioned light-emitting substrate, a circuit board, and a plurality of light-emitting units provided in an embodiment of the present invention;

[0078] The plurality of light emitting units are electrically connected to the plurality of first pads of the light emitting substrate, and the circuit board is electrically connected to the plurality of second pads of the light emitting substrate.

[0079] 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 and foldable). The display device can be: any product or component with a display function, such as a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, a navigator, etc. Other essential components of the display device should be understood by those of ordinary skill in the art, and will not be described in detail here, nor should they be used as limitations on the present invention. The principle of solving the problem by the display device is similar to that of the aforementioned light-emitting substrate, so the implementation of the display device can refer to the implementation of the aforementioned light-emitting substrate, and the repeated parts will not be described here.

[0080] The light-emitting substrate and display device provided by an embodiment of the present invention include a first pad in the light-emitting area of the light-emitting substrate including a first metal layer located on a base substrate and a second metal layer located on a side of the first metal layer facing away from the base substrate. The material of the second metal layer includes a copper-nickel-titanium alloy. Since nickel and titanium are resistant to oxidation, the present invention designs the number of nickel atoms and / or titanium atoms contained per unit area in a cross-section further away from the base substrate to be greater than the number of nickel atoms and / or titanium atoms contained per unit area in another cross-section closer to the base substrate. This allows the number of nickel atoms and / or titanium atoms on the surface of the second metal layer away from the base substrate to be greater, thereby making the surface of the second metal layer resistant to oxidation. Therefore, during the manufacturing process of the light-emitting substrate, the second metal layer in the light-emitting area will not oxidize, thereby avoiding the problem of oxidation during the manufacturing process of the light-emitting substrate. The second metal layer can thus protect the first metal layer and avoid oxidation of the first metal layer during the manufacturing process of the light-emitting substrate.

[0081] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A light-emitting substrate, characterized in that, It includes a substrate, the substrate having a light-emitting region, the light-emitting region including a plurality of first pads located on the substrate, and the plurality of first pads are used for bonding connection with a plurality of light-emitting units; Any one of the plurality of first pads includes: a first metal layer located on the substrate, and a second metal layer located on a side of the first metal layer away from the substrate; The material of the first metal layer includes copper, and the material of the second metal layer is a copper-nickel-titanium alloy; Among at least two cross-sections of the second metal layer parallel to the plane of the substrate, the number of nickel atoms per unit area in a cross-section farther from the substrate is more than the number of nickel atoms per unit area in another cross-section closer to the substrate; And / or, the number of titanium atoms per unit area in a cross-section farther from the substrate is more than the number of titanium atoms per unit area in another cross-section closer to the substrate.

2. The light-emitting substrate according to claim 1, wherein The thickness of the second metal layer is 30 nm - 100 nm.

3. The light-emitting substrate according to claim 1, wherein In the material of the second metal layer, the mass fraction of Cu accounts for 90% - 95%, the mass fraction of Ni accounts for 4.5% - 9%, and the mass fraction of Ti accounts for 0.5% - 1%.

4. The light-emitting substrate according to claim 3, wherein The material of the second metal layer further includes Si or C or O, and the mass fraction of any one of the Si, the C, and the O is less than 0.1%.

5. The light-emitting substrate according to claim 1, wherein The substrate further has a bonding region, the bonding region including a plurality of second pads located on the substrate, and the plurality of second pads are used for bonding connection with a circuit board; any one of the plurality of second pads includes: a third metal layer located on the substrate, and a fourth metal layer located on a side of the third metal layer away from the substrate; wherein, The third metal layer and the first metal layer are arranged in the same layer, and the fourth metal layer and the second metal layer are arranged in the same layer.

6. The light-emitting substrate according to claim 5, wherein, It further includes a first wiring layer located between the first pad and the substrate, the first wiring layer including a first metal sub-layer, a first wiring sub-layer, and a second metal sub-layer which are stacked; wherein, The first metal layer and the second metal sub-layer are electrically connected, and the third metal layer and the second metal sub-layer are electrically connected; The materials of the first metal sub-layer and the second metal sub-layer include a molybdenum-niobium alloy, and the material of the first wiring sub-layer includes copper.

7. The light-emitting substrate according to claim 6, characterized in that, The light-emitting region further includes: a first passivation layer located between the first wiring layer and the first metal layer, a first planarization layer located between the first passivation layer and the first metal layer, a second planarization layer located on a side of the second metal layer away from the substrate, and a first connection portion located on the second metal layer; the second planarization layer covers the region between the plurality of first pads.

8. The light-emitting substrate according to claim 7, wherein The bonding region further includes: a second passivation layer located between the first wiring layer and the third metal layer, a third planarization layer located between the second passivation layer and the third metal layer, a fourth planarization layer located on a side of the fourth metal layer away from the substrate, and a second connection portion located on the fourth metal layer; wherein, The fourth flat layer covers the area between the plurality of second pads; The third flat layer is arranged on the same layer as the first flat layer, the fourth flat layer is arranged on the same layer as the second flat layer, and the second passivation layer is arranged on the same layer as the first passivation layer.

9. The light-emitting substrate according to claim 7, wherein The plurality of first pads are divided into multiple groups of first pads, and each group of the first pads includes a cathode pad and an anode pad arranged in pairs; The light-emitting substrate further includes a second wiring layer arranged on the same layer as the plurality of first pads. The second wiring layer is used to realize the series connection or parallel connection of multiple groups of the first pads, and is further used to be electrically connected to the first wiring layer through vias penetrating the first flat layer and the first passivation layer.

10. The light-emitting substrate according to claim 5, characterized in that, It further includes a protective layer on the side of the first pads and the second pads away from the substrate. The protective layer exposes the first pads and the second pads, and the material of the protective layer includes silicon nitride or silicon oxide.

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

12. The display device according to claim 11, wherein, The light-emitting unit is a Mini LED or a MicroLED.

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