Light-emitting device and display device

Abstract

The invention discloses a light-emitting device and a display device. The light-emitting device comprises a plurality of light-emitting elements, a wiring layer, an insulating layer and a plurality of bonding pads arranged at intervals. Wherein the plurality of light-emitting elements are arranged at intervals. The wiring layer is formed over the plurality of light-emitting elements and is electrically connected to each of the light-emitting elements. The insulating layer covers the wiring layer, an opening is formed in the insulating layer, and part of the wiring layer is exposed out of the opening. A plurality of bonding pads arranged at intervals are formed on the wiring layer in the opening, each bonding pad comprises an electrode protection layer, the electrode protection layer comprises a tin alloy layer, and the tin alloy layer is formed above the wiring layer exposed in the opening. Therefore, the tin alloy layer can avoid oxidation of copper metal of the wiring layer. And meanwhile, the formed tin alloy layer can also be used as a welding layer during subsequent die bonding, so that the cost can be reduced, and the die bonding yield and the device reliability are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a light-emitting device and a display device. Background Art

[0002] Light-emitting diodes are widely used in display devices, vehicle lamps, general lighting lamps and other fields due to their high reliability, long life and low power consumption. For example, light-emitting diodes can be used as backlight sources for various display devices. At present, the size of micro-chips (micro-LED chips, generally less than 100nm) is too small, and it is difficult to grab the chips and fix them on the display panel. Therefore, the three RGB chips are formed into a unit pixel package, so that the process of grabbing the unit pixel and fixing it to the display panel is relatively simple.

[0003] Due to the need to control manufacturing costs and take into account the conductivity of components, metal copper is selected as the conductive electrode for the unit pixel package. However, the exposed copper surface is easily oxidized by air, which affects the electrode welding and current conduction of the unit pixel package. In order to prevent the oxidation of copper on the electrode surface, a layer of metal that is not easily oxidized is usually added to the electrode surface as a surface protection layer. When applied, it is also necessary to add solder paste and other flux to the electrode and the pad for heating and welding to fix the connection and complete the circuit connection. Although these commonly used metal materials are relatively stable in nature, they occupy a higher cost in production, reducing the market competitiveness of the product. At the same time, the use of solder paste during welding is also likely to affect the device yield. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a light-emitting device and a display device to further reduce the manufacturing cost and improve the device yield.

[0005] In order to achieve the above-mentioned object and other related objects, the present invention provides a light emitting device, comprising:

[0006] A plurality of light-emitting elements, wherein the plurality of light-emitting elements are arranged at intervals;

[0007] A wiring layer is formed above the plurality of light emitting elements and is electrically connected to each of the light emitting elements;

[0008] An insulating layer covers the wiring layer, an opening is formed on the insulating layer, and a portion of the wiring layer is exposed in the opening;

[0009] A plurality of pads arranged at intervals are formed on the wiring layer in the opening, the pads include an electrode protection layer, the electrode protection layer includes a tin alloy layer, and the tin alloy layer is formed above the wiring layer exposed in the opening.

[0010] According to one aspect of the present invention, a display device is further provided, comprising the above-mentioned light-emitting device.

[0011] Compared with the prior art, the light emitting device and the display device of the present invention have at least the following beneficial effects:

[0012] The light-emitting device of the present invention comprises a plurality of light-emitting elements, a wiring layer, an insulating layer and a plurality of pads arranged at intervals. Among them, the plurality of light-emitting elements are arranged at intervals. The wiring layer is formed above the plurality of light-emitting elements and is electrically connected to each light-emitting element. The insulating layer covers the wiring layer, and an opening is formed on the insulating layer, and the opening exposes a portion of the wiring layer. A plurality of pads arranged at intervals are formed on the wiring layer in the opening, and the pad comprises an electrode protection layer, and the electrode protection layer comprises a tin alloy layer, and the tin alloy layer is formed above the wiring layer exposed in the opening. Thus, the tin alloy layer is directly formed above the wiring layer, which can avoid oxidation of copper metal in the wiring layer. At the same time, the formed tin alloy layer can also be used as a welding layer during subsequent solid crystal bonding. During subsequent solid crystal bonding, there is no need to apply solder paste separately to achieve solid crystal packaging of the light-emitting device. By directly forming the tin alloy layer on the light-emitting device, the problem of short circuit caused by the migration of solder paste due to the subsequent coating of solder paste is avoided, and the formed tin alloy layer has a uniform thickness, a relatively flat surface, and a relatively uniform thickness. During solid soldering, there will be no skew, displacement, or overflow of solder paste in the solid crystal, which is beneficial to the solid crystal yield.

[0013] The display device of the present invention includes the above-mentioned light-emitting device and also has the above-mentioned technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic diagram of a top view of the structure of the light emitting device in Embodiment 1 of the present invention;

[0015] Figure 2 For along Figure 1 A-A' sectional view;

[0016] Figure 3 is a schematic diagram of a top view of the structure of a light emitting device in Embodiment 2 of the present invention;

[0017] Figure 4 For along Figure 3 Middle B-B' section view;

[0018] Figure 5 A schematic diagram of a top view of a light emitting device in an example of Embodiment 2 of the present invention;

[0019] Figure 6 A schematic diagram of a top view of a light emitting device in an example of Embodiment 2 of the present invention;

[0020] Figure 7 Schematic diagram of the top view of the light emitting device in another example of Embodiment 2 of the present invention.

[0021] List of reference numerals:

[0022] 100 Transparent Layer

[0023] 110 First transparent layer

[0024] 120 Second transparent layer

[0025] 201 first light emitting element

[0026] 202 second light emitting element

[0027] 203 third light emitting element

[0028] 300 driver chip

[0029] 400 Filling Layers

[0030] 500 wiring layers

[0031] 600 Insulation

[0032] 700 Pad

[0033] 710 Nickel layer

[0034] 720 Tin alloy layer

[0035] 701 First driving pad

[0036] 702 Second driving pad

[0037] 703 Third drive pad

[0038] 7041 First other pad

[0039] 7042 Second other pad

[0040] 7043 Third other pad DETAILED DESCRIPTION

[0041] The following specific embodiments illustrate the embodiments of the present invention, and those familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0042] It should be noted that the diagrams provided in the embodiments of the present invention are only used to illustrate the basic concept of the present invention in a schematic manner. Although the diagrams only show the components related to the present invention rather than being drawn according to the number, shape and size of the components in actual implementation, the form, quantity and proportion of each component can be changed at will during actual implementation, and the layout of the components may also be more complex. The structures, proportions, sizes, etc. illustrated in the drawings of the specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions that can be implemented in this application, so they have no technical substantive significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in this application without affecting the effects and purposes that can be achieved by the present invention.

[0043] In order to reduce manufacturing costs and improve the die bonding yield and reliability of a light-emitting device, this embodiment provides a light-emitting device, including:

[0044] A plurality of light-emitting elements, wherein the plurality of light-emitting elements are arranged at intervals;

[0045] A wiring layer is formed above the plurality of light emitting elements and is electrically connected to each of the light emitting elements;

[0046] An insulating layer covers the wiring layer, an opening is formed on the insulating layer, and a portion of the wiring layer is exposed in the opening;

[0047] A plurality of pads arranged at intervals are formed on the wiring layer in the opening, and the pads include an electrode protection layer, and the electrode protection layer is a tin alloy layer, and the tin alloy layer is formed above the wiring layer exposed in the opening. Thus, the tin alloy layer is directly formed above the wiring layer, which can avoid oxidation of the copper metal in the wiring layer. At the same time, the formed tin alloy layer can also be used as a welding layer during subsequent solid crystal bonding. During subsequent solid crystal bonding, there is no need to apply solder paste separately to achieve solid crystal packaging of the light-emitting device. The method of directly forming the tin alloy layer on the light-emitting device avoids the subsequent coating of solder paste and the short circuit problem caused by the migration of solder paste. The formed tin alloy layer has a uniform thickness, a relatively flat surface, and a relatively uniform thickness. During solid soldering, there will be no skew, displacement, or overflow of solder paste in the solid crystal, which is beneficial to the solid crystal yield.

[0048] Optionally, the tin alloy layer includes one or more of gold, platinum, palladium, silver and titanium. Other metals in the tin alloy layer except the tin alloy layer can increase the solderability and stability of tin.

[0049] Optionally, the tin alloy layer is partially located in the opening and partially higher than the surface of the insulating layer, wherein the portion higher than the surface of the insulating layer facilitates subsequent soldering and packaging.

[0050] Optionally, a height of the tin alloy layer in the opening is smaller than a height of the tin alloy layer above the surface of the insulating layer.

[0051] Optionally, the surface of the tin alloy layer higher than the insulating layer is a flat surface. The tin alloy layer formed by chemical plating is subsequently uniform and has a flat surface, which will not cause the die bonding to be skewed, shifted, or overflow with solder paste, which is beneficial to the die bonding yield and device reliability.

[0052] Optionally, the tin alloy layer is a tin-silver layer. Compared with the nickel-gold layer, the material cost of the tin-silver layer is lower, and no additional tin paste is required, thus avoiding the cost waste caused by the tin paste coating. The tin-silver layer is less susceptible to oxidation than the copper layer, and can isolate the easily oxidized surface from contact with air. At the same time, the tin-silver layer has good electrical conductivity, thermal conductivity and corrosion resistance, and the silver metal therein can increase the solderability and stability of tin.

[0053] Optionally, the silver content in the tin-silver layer is 1% to 2%. This ratio setting makes the tin-silver layer have better welding performance, a denser surface, and is easier to use.

[0054] Optionally, the electrode protection layer further comprises a bonding layer, and the bonding layer is located between the wiring layer and the tin alloy layer in the opening. In this embodiment, the bonding layer is provided between the wiring layer and the tin alloy layer, which can improve the bonding force between the wiring layer and the tin alloy layer, and is beneficial to the reliability of the device.

[0055] Optionally, the thickness of the bonding layer is less than that of the insulating layer, and the bonding layer is located in the opening of the insulating layer. In this case, the interface between the bonding layer and the tin alloy layer is covered by the insulating layer, which can reduce the interface force between the bonding layer and the tin alloy layer, and improve the stability and the solid crystal thrust value.

[0056] Optionally, the thickness of the tin alloy layer is greater than the thickness of the bonding layer.

[0057] Optionally, the thickness of the tin alloy layer is between 8 μm and 30 μm, and the thickness of the bonding layer is between 1 μm and 6 μm.

[0058] Optionally, the bonding layer is a nickel layer, which, in addition to being a bonding layer, can also be used as a barrier layer to prevent element diffusion, improve interface bonding strength, improve component welding performance, provide a better welding surface, and improve welding reliability. Optionally, the wiring layer contains copper. Since the exposed wiring layer contains copper metal, copper is easily oxidized, a layer structure to prevent oxidation needs to be provided on the wiring layer.

[0059] Optionally, the light emitting device further comprises:

[0060] A transparent layer, a plurality of light emitting elements are arranged at intervals on the transparent layer, and a side of the plurality of light emitting elements away from the wiring layer is in contact with the transparent layer.

[0061] Optionally, the transparent layer comprises:

[0062] First transparent layer;

[0063] The second transparent layer is arranged on the first transparent layer, and a plurality of light emitting elements are arranged on the second transparent layer at intervals.

[0064] Optionally, the light emitting device further comprises:

[0065] The filling layer is filled between adjacent light-emitting elements and around the periphery of the plurality of light-emitting elements.

[0066] Optionally, the multiple light-emitting elements include a first light-emitting element, a second light-emitting element and a third light-emitting element, the first light-emitting element is a light-emitting element radiating blue light, the second light-emitting element is a light-emitting element radiating green light, and the third light-emitting element is a light-emitting element radiating red light.

[0067] Optionally, the plurality of pads arranged at intervals include:

[0068] The driving pad is connected to one electrode of multiple light-emitting elements at the same time;

[0069] The other plurality of pads are connected to the other electrodes of the plurality of light emitting elements in a one-to-one correspondence.

[0070] Optionally, the light emitting device further comprises:

[0071] The driving chip is arranged above the transparent layer with a plurality of light emitting elements spaced apart from each other and is electrically connected to the plurality of light emitting elements through a wiring layer; or is arranged above the plurality of light emitting elements and is electrically connected to the plurality of light emitting elements through a wiring layer.

[0072] Optionally, the plurality of pads arranged at intervals include:

[0073] At least two driving pads, including a first driving pad and a second driving pad, the first driving pad drivingly connected to at least two light-emitting elements, and the second driving pad drivingly connected to at least a driving chip;

[0074] A plurality of other pads are electrically connected to different terminals on the driver chip respectively.

[0075] Using a separate driving pad to drive a light-emitting element with inconsistent driving voltages, or using a separate driving pad to drive a driving chip, can avoid energy loss caused by inconsistent driving voltages between light-emitting elements, or between light-emitting elements and driving chips. In addition, it can also avoid damage to the light-emitting element caused by mismatched driving voltages, which is beneficial to the reliability and service life of the light-emitting element.

[0076] This embodiment also provides a display device, including:

[0077] Display substrate;

[0078] At least one light emitting device is disposed on the surface of the display substrate. The light emitting device is electrically connected to the display substrate. The light emitting device is the above-mentioned light emitting device. It can also reduce manufacturing costs and improve die bonding yield and device reliability.

[0079] The present invention is described in detail below with reference to specific embodiments.

[0080] Example 1

[0081] This embodiment provides a light emitting device, referring to Figure 1 The light emitting device includes a plurality of light emitting elements (201, 202, 203), a wiring layer 500, an insulating layer 600 and a plurality of pads 700 arranged at intervals.

[0082] In this embodiment, refer to Figure 1 Combination Figure 2 , a plurality of light-emitting elements (201, 202, 203) are arranged at intervals on the transparent layer 100. Among them, the transparent layer 100 can have a light transmittance of more than 60% in the visible light range. The transparent layer 100 includes a first surface and a second surface arranged opposite to each other, and the first surface is a light-emitting surface, that is, the light emitted by the light-emitting element is emitted outward through the first surface of the transparent layer 100. The light-emitting device needs to have a certain thickness for easy use by the client, so the thickness of the transparent layer 100 is preferably greater than 10μm, and specifically preferably 30μm to 50μm, 50μm to 100μm or 100μm to 300μm. In this embodiment, the transparent layer 100 includes a first transparent layer 110 and a second transparent layer 120, and the first transparent layer 110 is a transparent substrate. Optionally, the transparent substrate can be a light-transmitting substrate such as PET, glass, quartz, sapphire, transparent ceramics, etc. The second transparent layer 120 is an adhesive layer or a transfer layer, wherein the material of the second transparent layer 120 can be an elastic material such as silicone, so that the light-emitting element will be partially sunken into the second transparent layer 120 to keep the electrode surface of the light-emitting element at the same level, and the height difference of the light-emitting surface of each light-emitting element can be reduced, so that the light emitted from the side of the light-emitting element is absorbed by the filling layer 300 described below as much as possible, so as to improve the contrast of the light-emitting device. The thickness of the second transparent layer 120 is preferably 1μm to 15μm or 3μm to 10μm. If the thickness of the second transparent layer 120 is greater than 15μm, the alignment accuracy of the light-emitting element may be affected.

[0083] A plurality of light-emitting elements arranged at intervals are disposed on the second surface of the transparent layer 100. The light-emitting element in this embodiment mainly refers to a micrometer-level light-emitting diode, whose width or length ranges from 2 to 5 μm, 5 to 10 μm, 10 to 20 μm, 20 to 50 μm or 50 to 100 μm, and whose thickness ranges from 2 to 15 μm, preferably 5 to 10 μm. Specifically, each light-emitting element includes a semiconductor stack layer, and the semiconductor stack layer may include a first semiconductor layer, a second semiconductor layer arranged in sequence, and an active layer disposed therebetween, wherein the first semiconductor layer is an N-type semiconductor layer, the second semiconductor layer is a P-type semiconductor layer, and the active layer is a multi-layer quantum well layer, which can provide red light, green light or blue light radiation. The N-type semiconductor layer, the multi-layer quantum well layer, and the P-type semiconductor layer are only the basic constituent units of the light-emitting element. On this basis, the light-emitting element may also include other functional structural layers that have an optimizing effect on the performance of the light-emitting element.

[0084] In this embodiment, refer to Figure 1 The plurality of light emitting elements include a first light emitting element 201, a second light emitting element 202, and a third light emitting element 203. The first light emitting element 201, the second light emitting element 202, and the third light emitting element 203 radiate light of different wavelength ranges, respectively. For example, the first light emitting element 201 radiates blue light, the second light emitting element 202 radiates green light, and the third light emitting element 203 radiates red light. In one embodiment, different light emitting elements may have different semiconductor stacking layers, so as to directly radiate light of different wavelength ranges. The specific material of the semiconductor stacking layer is selected according to the wavelength of the radiated light, and includes but is not limited to aluminum gallium arsenide, gallium arsenide phosphide, aluminum gallium indium phosphide, gallium nitride, indium gallium nitride, zinc selenide, or gallium phosphide. In another embodiment, different light-emitting elements may have the same semiconductor stacking layer, for example, the semiconductor stacking layers in the first light-emitting element 201, the second light-emitting element 202, and the third light-emitting element 203 all radiate blue light, and a wavelength conversion layer is provided on the light-emitting surface of the second light-emitting element 202 to convert the radiated blue light into green light, and a wavelength conversion layer is provided on the light-emitting surface of the third light-emitting element 203 to convert the radiated blue light into red light. Each light-emitting element further includes a first electrode and a second electrode. The semiconductor stacking layer has a table surface exposing the first semiconductor layer, the first electrode is formed on the table surface and electrically connected to the first semiconductor layer, and the second electrode is formed on the second semiconductor layer and electrically connected to the second semiconductor layer.

[0085] Reference Figure 2A filling layer 400 is provided between adjacent light-emitting elements or around the side walls of the light-emitting elements. The provision of the filling layer 400 can prevent color mixing or light interference between adjacent light-emitting elements, thereby improving the contrast of the light-emitting device. The filling layer 400 is provided as a black glue layer that absorbs light. Specifically, the filling layer 400 can be a component formed by dispersing a black filling component with a particle size not greater than 1 μm in a transparent or translucent material such as silica gel, epoxy resin, polyimide, low-temperature glass, polysiloxane, polysilazane, etc. The black filling component in the filling layer 400 includes but is not limited to carbon black, titanium nitride, iron oxide, ferroferric oxide, iron powder, etc. The particle size range of the black filling component is preferably 10 to 100 nm, or 100 to 200 nm, or 200 to 300 nm, or 300 nm to 500 nm. The filling layer 400 can also be made of black dye.

[0086] Reference Figure 2 The wiring layer 500 is disposed above the light emitting element and the filling layer 400, and is electrically connected to each light emitting element through the metal wiring therein. The wiring layer 500 includes a plurality of wirings, and the wiring layer 500 is surrounded by an insulating layer 600 to electrically isolate adjacent wirings. The wiring layer 500 may be a single layer or multiple layers made of at least one material selected from titanium, copper, chromium, nickel, gold, platinum, aluminum, titanium nitride, tantalum nitride or tantalum.

[0087] Reference Figure 2 The insulating layer 600 is formed on the wiring layer 500, and a portion of the insulating layer 600 can be removed by exposure and development, forming a plurality of openings to expose a portion of the surface of the wiring layer 500. The insulating layer 600 can be formed of materials such as epoxy resin, polysiloxane or photoresist, which can prevent the wiring layer 500 from being oxidized, and electrically isolate different wirings to prevent leakage failure of the light-emitting device.

[0088] Reference Figure 1 and Figure 2 , a plurality of pads 700 arranged at intervals are formed on the wiring layer 500 in the opening of the insulating layer 600. The plurality of pads 700 are respectively a first driving pad 701, a first other pad 7041, a second other pad 7042 and a third other pad 7043. The first driving pad 701 is electrically connected to the first electrodes of the first light-emitting element 201, the second light-emitting element 202 and the third light-emitting element 203 for driving the three light-emitting elements. The first other pad 7041, the second other pad 7042 and the third other pad 7043 are respectively electrically connected to the second electrodes of the first light-emitting element 201, the second light-emitting element 202 and the third light-emitting element 203.

[0089] In the prior art, since the copper exposed on the surface of the exposed wiring layer 500 is easily oxidized by air, nickel-gold is generally plated on the exposed copper surface to prevent copper oxidation on the surface. In subsequent applications, solder paste is generally applied on the nickel-gold surface to encapsulate and fix it. However, the cost of nickel-gold materials is relatively high, and the conventional solder paste brushing process has the risk of short circuit caused by solder paste migration. In addition, uneven solder paste dosage can easily lead to skewed solid crystals, offset solid crystal positions, solder paste overflow, and waste of solder paste.

[0090] In order to solve the background technology and the above-mentioned technical problems, the present embodiment improves the pad structure. Specifically, in the present embodiment, referring to Figure 2 , each pad 700 includes an electrode protection layer, and the electrode protection layer includes a tin alloy layer 720. Thus, the tin alloy layer 720 is directly formed above the wiring layer 500, which can avoid oxidation of the copper metal of the wiring layer 500. At the same time, the formed tin alloy layer 720 can also be used as a welding layer during subsequent solid crystal bonding. During subsequent solid crystal bonding, there is no need to apply solder paste separately. Only a thin layer of flux is applied on the surface of the tin alloy layer 720 to achieve solid crystal packaging of the light-emitting device. The method of directly forming the tin alloy layer 720 on the light-emitting device avoids the problem of solder paste migration caused by subsequent solder paste coating. The formed tin alloy layer 720 has a uniform thickness, a relatively flat surface, and a relatively uniform thickness. During solid soldering, there will be no skew, displacement, or overflow of solder paste in the solid crystal, which is beneficial to the solid crystal yield. At the same time, it can also avoid direct coating of solder paste and the cost waste caused by the overflow of solder paste. Avoiding solder paste can also improve production efficiency. Optionally, other metals in the tin alloy layer 720 include one or more of gold, platinum, palladium, silver, and titanium. In the present embodiment, the tin alloy layer 720 is a tin-silver layer, which has lower consumables cost than nickel-gold plating. Optionally, the silver content in the tin-silver layer is 1% to 2%. Optionally, the thickness of the tin alloy layer 720 is greater than the thickness of the insulating layer 600, so that part of the tin alloy layer 720 extends from the opening of the insulating layer 600 and is higher than the surface of the insulating layer 600, so as to facilitate subsequent welding. Optionally, the height of the tin alloy layer 720 located in the opening is less than the height of the tin alloy layer 720 higher than the surface of the insulating layer 600. Optionally, each pad 700 may also include other layers arranged between the wiring layer 500 and the electrode protection layer, which is not limited in the present embodiment. In the present embodiment, the electrode protection layer is directly used as the pad 700 without adding other layers, which is conducive to material saving and reducing manufacturing costs.

[0091] In an alternative embodiment, reference Figure 2In order to increase the bonding between the copper in the wiring layer 500 and the tin alloy layer 720, a bonding layer 710 is formed between the wiring layer 500 and the tin alloy layer 720 in the opening of the insulating layer 600. The bonding layer 710 is formed on the wiring layer 500 exposed in the opening, and the tin alloy layer 720 is formed on the bonding layer 710. Such a configuration can increase the adhesion between the wiring layer 500 and the tin alloy layer 720, which is beneficial to the reliability of the light-emitting device. In this embodiment, the bonding layer 710 is a nickel layer. In addition to being a bonding layer, the nickel layer can also be used as a barrier layer to prevent element diffusion, improve the interface bonding strength, improve the welding performance of components, provide a better welding surface, and improve the reliability of welding.

[0092] In this embodiment, refer to Figure 2 , the thickness of the nickel layer 710 is less than the thickness of the insulating layer 600, and the nickel layer 710 is located in the opening of the insulating layer 600 and is covered by the insulating layer 600. Optionally, the thickness of the nickel layer 710 is less than or equal to half of the thickness of the insulating layer 600, for example, the thickness of the insulating layer 600 is 6μm, and the thickness of the nickel layer 710 is 3μm. The tin alloy layer 720 is formed on the nickel layer 710 in the opening, and the tin alloy layer 720 is partially covered by the insulating layer 600 and partially protrudes from the surface of the insulating layer 600. At this time, the interface between the nickel layer 710 and the tin alloy layer 720 is covered by the insulating layer 600, which can reduce the interface force between the nickel layer 710 and the tin alloy layer 720, improve stability and solid crystal thrust value, and the portion of the tin alloy layer 720 protruding from the insulating layer 600 is used for subsequent welding. Optionally, the nickel layer 710 is also formed by chemical plating to ensure the uniformity of the subsequent formation of the chemically plated tin alloy layer 720 and the bonding force between the wiring layer 500 and the tin alloy layer 720, thereby improving the solid crystal thrust value. Similarly, the tin alloy layer 720 can be a tin-silver layer to further reduce the cost of consumables. Optionally, the silver content in the tin-silver layer is 1% to 2%. The thickness of the tin-silver layer is greater than the thickness of the nickel layer 710, and the thickness of the nickel layer 710 is 1 to 6 μm, for example, 3 μm, and the thickness of the tin-silver layer is 8 μm to 30 μm, for example, 10 μm. The thickness of the tin-silver layer can be set to the same thickness as conventional solder paste welding to facilitate welding at the application end.

[0093] Example 2

[0094] This embodiment provides a light emitting device, referring to Figure 3 and 4 The solder pad 700 in the light emitting device also includes the tin alloy layer 720 in Example 1 or includes the nickel layer 710 and the tin alloy layer 720. The similarities are not repeated here. The differences are as follows:

[0095] In this embodiment, refer to Figure 3 , 4 Or 5, the light emitting device further includes a driving chip 300, such as Figure 3 and4 As shown, the driving chip 300 can be disposed on the transparent layer 100 and spaced apart from the plurality of light emitting elements (201, 202, 203); Figure 5 As shown, it can also be arranged above the light-emitting elements (201, 202, 203), and stacked up and down with the light-emitting elements (201, 202, 203). The driver chip 300 is used to process the data signals of the controller and the pixel points. A plurality of terminals are arranged on the surface of the driver chip 300, and each light-emitting element is electrically connected to different terminals on the driver chip 300 through a wiring layer. Optionally, the driver chip 300 is an active driver IC chip. The use of an active driver IC chip can improve the display quality of the light-emitting device, and can be driven at a lower driving voltage, thereby increasing the service life of the display device. The positions of the driver chip 300 and the light-emitting element on the transparent layer 100 can be arbitrary, as long as they do not affect the arrangement of other structures. In order to avoid the driver chip 300 being too large in size, occupying too much space in the entire light-emitting device, and affecting the light output of the light-emitting part. The size of the driver chip 300 is between about 1μm and 110μm. Specifically, the size of the driving chip 300 may be 5 μm, 10 μm, 20 μm, 50 μm, 70 μm or 100 μm.

[0096] Optionally, the pad 700 includes at least two driving pads and a plurality of other pads, wherein the at least two driving pads are respectively a first driving pad 701 and a second driving pad 702, wherein the first driving pad 701 drives and connects at least two light-emitting elements, and the second driving pad 702 at least drives and connects the driver chip 300. There are three other pads 704, namely a first other pad 7041, a second other pad 7042 and a third other pad 7043. Among them, the three other pads 704 are respectively electrically connected to other different terminals on the driver chip 300. The first other pad 7041 (Row / Clk) and the second other pad 7042 (Col / Data) are grounded by inputting data signals and timing signals to the driver chip 300, and the third other pad 7043 (Gnd) is electrically connected to the driver chip 300.

[0097] In one example, the at least two driving pads include a first driving pad 701 and a second driving pad 702. The first driving pad 701 (VGB) is electrically connected to the first light-emitting element 201 and the second light-emitting element 202, and a driving voltage is input thereto. The second driving pad 702 (VR) is electrically connected to the third light-emitting element 203 and the driving chip 300, so as to input a driving voltage to the third light-emitting element 203 and the driving chip 300 at the same time.

[0098] In another example, the at least two driving pads include a first driving pad 701, a second driving pad 702, and a third driving pad 703. The first driving pad 701 (VGB) is electrically connected to the first light-emitting element 201 and the second light-emitting element 202, and a driving voltage is input thereto. The second pad is electrically connected to the driving chip 300 to input a driving voltage to the driving chip 300. The third driving pad 703 (VR) is electrically connected to the third light-emitting element 203 to input a driving voltage to the third light-emitting element 203 alone.

[0099] In another example, the at least two driving pads include a first driving pad 701 and a second driving pad 702. The first driving pad 701 (VGB) is electrically connected to the first light emitting element 201, the second light emitting element 202, and the third light emitting element 203, and a driving voltage is input thereto. The second driving pad 702 is electrically connected to the driving chip 300 to input a driving voltage to the driving chip 300.

[0100] In the above three examples, a separate driving pad is used to drive the third light emitting element 203 (red light emitting element), or a separate driving pad is used to drive the driving chip, which can avoid energy loss caused by inconsistent driving voltages between light emitting elements, or between the light emitting elements and the driving chip 300. In addition, it can also avoid damage to the light emitting element caused by mismatched driving voltages, which is beneficial to the reliability and service life of the light emitting element.

[0101] Example 3

[0102] This embodiment provides a display device, which includes a display substrate and at least one light-emitting device disposed on the display substrate. The light-emitting device is the light-emitting device in Embodiment 1.

[0103] Specifically, the pad of each light emitting device is electrically connected to the display substrate, and the light emitting surface of the light emitting device is away from the display substrate. When there are more than two light emitting devices, more than two light emitting devices are arranged at intervals on the display substrate, and each light emitting device is electrically connected to the display substrate.

[0104] Since the light emitting device included in this embodiment is the light emitting device mentioned above, it also has the technical effects of low manufacturing cost, high die bonding yield and high device reliability.

[0105] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A light emitting device, characterized in that: include: A plurality of light emitting elements, wherein the plurality of light emitting elements are arranged at intervals; A wiring layer formed above the plurality of light emitting elements and electrically connected to each of the light emitting elements; an insulating layer, covering the wiring layer, wherein an opening is formed on the insulating layer, and the opening exposes a portion of the wiring layer; A plurality of pads are arranged at intervals and are formed on the wiring layer in the opening. The pads include an electrode protection layer. The electrode protection layer includes a tin alloy layer. The tin alloy layer is formed above the wiring layer exposed in the opening.

2. The light emitting device according to claim 1, characterized in that: The tin alloy layer also includes one or more of gold, platinum, palladium, silver and titanium.

3. The light emitting device according to claim 1, characterized in that: The tin alloy layer is partially located in the opening and partially protrudes above the surface of the insulating layer.

4. The light emitting device according to claim 3, characterized in that: The height of the tin alloy layer in the opening is smaller than the height of the tin alloy layer above the surface of the insulating layer.

5. The light emitting device according to claim 3, characterized in that The surface of the tin alloy layer higher than the insulating layer is a flat surface.

6. The light emitting device according to claim 1, characterized in that: The tin alloy layer is a tin-silver layer.

7. The light emitting device according to claim 6, characterized in that: The content of silver in the tin-silver layer is 1% to 2%.

8. The light emitting device according to claim 1, characterized in that: The electrode protection layer further includes a bonding layer, and the bonding layer is located between the wiring layer and the tin alloy layer in the opening.

9. The light emitting device according to claim 8, characterized in that: The thickness of the bonding layer is smaller than that of the insulating layer, and the bonding layer is located in the opening of the insulating layer.

10. The light emitting device according to claim 8, characterized in that: The thickness of the tin alloy layer is greater than the thickness of the bonding layer.

11. The light emitting device according to claim 10, characterized in that: The thickness of the tin alloy layer is between 8 μm and 30 μm, and the thickness of the bonding layer is between 1 μm and 6 μm.

12. The light emitting device according to claim 8, characterized in that: The bonding layer is a nickel layer, and the wiring layer includes copper.

13. The light emitting device according to claim 1, characterized in that: The light emitting device further comprises: A transparent layer, the plurality of light emitting elements are arranged at intervals on the transparent layer, and a side of the plurality of light emitting elements away from the wiring layer is in contact with the transparent layer.

14. The light emitting device according to claim 13, characterized in that: The transparent layer comprises: First transparent layer; The second transparent layer is disposed on the first transparent layer, and the plurality of light emitting elements are disposed on the second transparent layer at intervals.

15. The light emitting device according to claim 1, characterized in that: The light emitting device further comprises: The filling layer is filled between adjacent light emitting elements and around the peripheries of the plurality of light emitting elements.

16. The light emitting device according to claim 1, characterized in that: The plurality of light-emitting elements include a first light-emitting element, a second light-emitting element and a third light-emitting element. The first light-emitting element is a light-emitting element radiating blue light, the second light-emitting element is a light-emitting element radiating green light, and the third light-emitting element is a light-emitting element radiating red light.

17. The light emitting device according to claim 1, characterized in that: The plurality of pads arranged at intervals include: The driving pad is connected to one electrode of the plurality of light emitting elements at the same time; The other plurality of pads are connected to the other electrodes of the plurality of light emitting elements in a one-to-one correspondence.

18. The light emitting device according to claim 1, characterized in that: The light emitting device further comprises: A driving chip is arranged above the transparent layer with intervals from the plurality of light-emitting elements and is electrically connected to the plurality of light-emitting elements through a wiring layer; or is arranged above the plurality of light-emitting elements and is electrically connected to the plurality of light-emitting elements through the wiring layer.

19. The light emitting device according to claim 18, characterized in that: The plurality of pads arranged at intervals include: At least two driving pads, including a first driving pad and a second driving pad, wherein the first driving pad is drivingly connected to at least two light-emitting elements, and the second driving pad is drivingly connected to at least the driving chip; A plurality of other pads are electrically connected to different terminals on the driving chip respectively.

20. A display device, characterized in that: include: Display substrate; At least one light-emitting device is disposed on the surface of the display substrate, the light-emitting device is electrically connected to the display substrate, and the light-emitting device is the light-emitting device according to any one of claims 1 to 19.

Images