Unit pixel

Abstract

The invention provides a unit pixel which comprises a plurality of light-emitting elements, and the light-emitting elements are arranged at intervals. The wiring layer is formed above the light-emitting element and is electrically connected with the light-emitting element, and the wiring layer comprises a first part, a second part connected with the first part and a third part extending from the first part to the edge of the unit pixel; an insulating layer formed on the wiring layer; wherein the thickness of at least part of the third part is smaller than that of the first part, and the thickness of at least part of the third part is smaller than that of the second part.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a unit pixel. Background Art

[0002] LED chips are widely used in display devices, vehicle lamps, general lighting and other fields due to their high reliability, long life and low power consumption. For example, LED RGB chips can be used as unit pixels of 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] However, the reliability of existing unit pixel packages is relatively poor, and how to obtain a unit pixel with high reliability is still a difficult problem. 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 unit pixel to improve the light-emitting effect and reliability.

[0005] In order to achieve the above-mentioned purpose and other related purposes, the present invention provides a unit pixel, comprising: a plurality of light-emitting elements, the plurality of light-emitting elements are arranged at intervals; a wiring layer, formed above the light-emitting elements, electrically connected to the light-emitting elements, the wiring layer comprising a first part, a second part connected to the first part, and a third part extending from the first part to the edge of the unit pixel; an insulating layer, formed on the wiring layer; wherein the thickness of at least part of the third part is less than the thickness of the first part, and the thickness of at least part of the third part is less than the thickness of the second part.

[0006] Furthermore, the insulating layer has an opening to expose a first portion of the wiring layer.

[0007] Furthermore, the thickness of the first portion is between 1.5 μm and 4 μm, the thickness of the second portion is between 1.5 μm and 4 μm, and the thickness of part of the third portion is between 0.5 μm and 1.2 μm.

[0008] Further, the third portion includes a portion close to an edge of the unit pixel and a portion far from the edge of the unit pixel, and a thickness of the portion close to the edge of the unit pixel is smaller than a thickness of the portion far from the edge of the unit pixel.

[0009] Furthermore, the thickness of the portion close to the edge of the unit pixel is between 0.5 μm and 1.2 μm, and the thickness of the portion far from the edge of the unit pixel is between 1.5 μm and 4 μm.

[0010] Furthermore, the third portion includes a first segment connected to the first portion and a second segment connected to the first segment, the second segment extends from the first segment to an edge of the unit pixel, and a thickness of the first segment is greater than a thickness of the second segment.

[0011] Further, the thickness of the second section is smaller than the thickness of the first portion and / or the second portion.

[0012] Furthermore, the length of the first segment is less than 35 μm, and the length of the second segment is greater than 5 μm.

[0013] Furthermore, the thickness of the first section is between 1.5 μm and 4 μm, and the thickness of the second section is between 0.5 μm and 1.2 μm.

[0014] Further, the first section includes a first layer and a second layer formed on the first layer, the second section does not include the second layer, and a thickness of the second layer is greater than 50% of a thickness of the first layer.

[0015] Further, the wiring layer includes a first layer and a second layer formed on a portion of the first layer, a surface of the first layer in contact with the second layer includes copper, and a surface of the second layer in contact with the first layer includes copper.

[0016] Furthermore, it also includes a protection electrode, which is formed on the first part.

[0017] Furthermore, the thickness of the protective electrode is greater than the thickness of the first portion.

[0018] The present invention further provides a unit pixel, comprising: a plurality of light-emitting elements, which are arranged at intervals; a wiring layer formed above the light-emitting elements and electrically connected to the light-emitting elements; an insulating layer formed on the wiring layer, the insulating layer having an opening portion exposing a portion of the surface of the wiring layer; a protective electrode formed in the opening portion of the insulating layer and in contact with the portion of the wiring layer; wherein the wiring layer includes a portion extending to the edge of the unit pixel having a first thickness and a portion located below the protective electrode having a second thickness, and the first thickness is less than the second thickness.

[0019] Furthermore, the thickness of the protective electrode is greater than the second thickness.

[0020] Furthermore, the wiring layer includes a first part, a second part connected to the first part, and a third part extending from the first part towards the edge of the unit pixel. The first part has a second thickness, the second part has a second thickness, and the third part has a first thickness.

[0021] Furthermore, the opening of the insulating layer exposes the first part of the wiring layer, and the protection electrode is formed on the first part of the wiring layer.

[0022] Furthermore, the first part includes a first layer and a second layer formed on the first layer. The second part includes a first layer and a second layer formed on the first layer. The third part does not include the second layer.

[0023] Furthermore, the thickness of the first layer is 0.05 μm to 1.5 μm, and the thickness of the second layer is 0.5 μm to 3 μm.

[0024] Furthermore, it further includes a transparent layer, a transfer layer, and a filling layer. The light-emitting element is disposed on the transparent layer. The transfer layer is located between the transparent layer and the light-emitting element. The filling layer is disposed between adjacent light-emitting elements. Description of the Drawings

[0025] Figure 1 A schematic plan view of a unit pixel according to an embodiment of the present application; Figure 2 Is along Figure 1 The schematic cross-sectional view taken along the cutting line A-A' of; Figure 3 A schematic diagram of the wiring layer; Figure 4 A schematic diagram of the first layer of the wiring layer; Figure 5 A schematic diagram of the second layer formed on the first layer in the wiring layer; Figure 6 For Figure 4 The enlarged schematic diagram of the local area A in; Figure 7 For Figure 5 The enlarged schematic diagram of the local area B in; Figure 8 A schematic plan view of a unit pixel according to another embodiment of the present application. Embodiments

[0026] 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.

[0027] 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.

[0028] Figure 1 is a schematic plan view for illustrating a unit pixel of the first embodiment of the present application, Figure 2 is along Figure 1 A schematic cross-sectional view taken along the line AA'.

[0029] This embodiment provides a unit pixel, referring to Figure 2 The unit pixel includes a transparent layer 100 , an adhesive layer 2000 , a plurality of light emitting elements, a filling layer 400 , a wiring layer 500 , an insulating layer 600 , and a protective electrode 700 .

[0030] Reference Figure 2 , the transparent layer 100 may have a light transmittance of more than 60% in the visible light range. Optionally, the transparent layer 100 may be a transparent substrate, and the transparent substrate may be a light-transmitting substrate such as PET, glass, quartz, sapphire, transparent ceramic, etc. The unit pixel 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, specifically preferably 30μm~50μm, 50μm~100μm, 100μm~150μm or 150μm~300μm. A plurality of light-emitting elements are arranged on the surface of the transparent layer 100. The side of the transparent layer 100 away from the light-emitting element is the light-emitting surface of the unit pixel, that is, the light emitted by the light-emitting element is emitted outward through the transparent layer 100.

[0031] Reference Figure 2 , multiple light-emitting elements are arranged on the transparent layer 100. Since different light-emitting elements usually have different thicknesses, an adhesive layer 200 is arranged between the transparent layer 100 and the light-emitting element, wherein the material of the adhesive layer 200 can be an elastic material such as silicone, so that the light-emitting element will partially sink into the adhesive layer 200 to keep the electrode surface of the light-emitting element at the same horizontal height, 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 400 described below as much as possible, so as to improve the contrast of the unit pixel. The thickness of the adhesive layer 200 is preferably 1μm~15μm or 3μm~10μm. If the thickness of the adhesive layer 200 is greater than 15μm, the alignment accuracy of the light-emitting element may be affected.

[0032] Reference Figure 1 and Figure 2 In this embodiment, the unit pixel includes a first light-emitting element 301, a second light-emitting element 302 and a third light-emitting element 303. The three light-emitting elements can radiate light of the same color, for example, the first light-emitting element 301, the second light-emitting element 302 and the third light-emitting element 303 can all be blue light-emitting elements; or they can emit light of different colors, for example, the first light-emitting element 301 is a red light-emitting element, the second light-emitting element 302 is a green light-emitting element, and the third light-emitting element 303 is a blue light-emitting element. 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.

[0033] Specifically, each light-emitting element includes a semiconductor stack layer, which may include a first semiconductor layer, a second semiconductor layer, and an active layer arranged in sequence, 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.

[0034] The first light-emitting element 301, the second light-emitting element 302 and the third light-emitting element 303 radiate light of different wavelength ranges, respectively, for example, the first light-emitting element 301 radiates blue light, the second light-emitting element 302 radiates green light, and the third light-emitting element 303 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, and the specific material of the semiconductor stacking layer is selected according to the wavelength of the radiated light, including but 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 301, the second light-emitting element 302 and the third light-emitting element 303 all radiate blue light, and a wavelength conversion layer is set on the light-emitting surface of the second light-emitting element 302 to convert the radiated blue light into green light, and a wavelength conversion layer is set on the light-emitting surface of the third light-emitting element 303 to convert the radiated blue light into red light.

[0035] Each light emitting element further includes a first electrode and a second electrode. The semiconductor stack layer has a mesa exposing the first semiconductor layer, the first electrode is formed on the mesa 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.

[0036] Reference Figure 2 A 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 unit pixel. 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 10~100nm, or 100~200nm, or 200~300nm, or 300nm~500nm. The filling layer 400 can also be made of black dye.

[0037] The filling layer 400 covers at least 50% of the side wall of the light-emitting element close to the light-emitting surface, preferably covers the entire side wall of the light-emitting element, which can prevent color mixing or light interference between adjacent light-emitting elements to improve the contrast of the unit pixel. As an alternative embodiment, the thickness of the filling layer 400 can be greater than the thickness of the light-emitting element, which can prevent light interference caused by light leakage from the bottom of the light-emitting element. The thickness of the filling layer 400 is preferably less than 15μm.

[0038] Reference Figure 1 and Figure 2 The wiring layer 500 is disposed above the light emitting elements and the filling layer 400 , and is electrically connected to each light emitting element through metal wiring therein.

[0039] like Figure 1 As shown, the wiring layer 500 includes a first sub-wiring 510, a second sub-wiring 520, a third sub-wiring 530 and a fourth sub-wiring 540, wherein the first sub-wiring 510 is used as a common wiring, the first electrodes in the first light-emitting element 301, the second light-emitting element 302 and the third light-emitting element 303 are commonly connected to the first sub-wiring 510, the second electrode in the first light-emitting element 301 is connected to the second sub-wiring 520, the second electrode in the second light-emitting element 302 is connected to the third sub-wiring 530, and the second electrode in the third light-emitting element 303 is connected to the fourth sub-wiring 540. The wiring layer 500 can be formed together on the filling layer 400.

[0040] Alternatively, the first sub wiring 510 is used as a common wiring, and the second electrodes in the first light-emitting element 301, the second light-emitting element 302, and the third light-emitting element 303 are commonly connected to the first sub wiring 510, the first electrode in the first light-emitting element 301 is connected to the second sub wiring 520, the first electrode in the second light-emitting element 302 is connected to the third sub wiring 530, and the first electrode in the third light-emitting element 303 is connected to the fourth sub wiring 540. The wiring layer 500 can be formed together on the filling layer 400.

[0041] The insulating layer 600 is located on the upper surface of the wiring layer 500 and fills the periphery of the wiring in the wiring layer 500. The insulating layer 600 is provided with an opening located above the wiring layer 500 and used to form the protection electrode 700. The number of the above-mentioned openings is the same as the number of the protection electrodes 700, that is, one protection electrode 700 corresponds to one opening.

[0042] When the material forming the wiring layer 500 is easily oxidized, for example, in one embodiment, when the surface metal of the wiring layer 500 is Cu, the protective electrode 700 can be formed to protect the exposed wiring layer 500. A plurality of protective electrodes 700 are formed on the exposed wiring layer 500 and are electrically connected to the wiring layer 500.

[0043] The insulating layer 600 may be a member 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 avoid leakage failure of unit pixels.

[0044] In one embodiment, the material of the protection electrode 700 may be one or more of nickel, gold, platinum, etc., or may be chromium, tin, or palladium. The thickness of the protection electrode 700 is between 1 and 6 μm, for example, the thickness of the protection electrode 700 may be 2 μm, 3 μm, 4 μm, 5 μm, etc.

[0045] In one embodiment, the protection electrode 700 includes a first layer structure and a second layer structure, the thickness of the first layer structure is greater than the thickness of the second layer structure, in a preferred embodiment, the first layer structure may be a nickel layer, the second layer structure may be a gold layer, the thickness of the first layer structure is 2μm~5μm, and the thickness of the second layer structure is 20 Å~50 Å, and the setting of this thickness ratio can achieve better flatness. In one embodiment, the wiring layer 500 includes copper metal. For example, when the surface metal is copper, part of the copper metal contacts the insulating layer 600, and part of the copper metal is exposed by the opening of the insulating layer 600, thereby contacting the protection electrode 700 and being protected by the protection electrode 700 to prevent oxidation.

[0046] Figure 3 is a schematic diagram of the wiring layer. Figure 4 This is a schematic diagram of the first wiring layer. Figure 5 This is a schematic diagram of a wiring layer in which a second layer is formed on a first layer.

[0047] like Figure 3 As shown, each sub-wiring in the wiring layer 500 includes a first part, a second part and a third part. Now, the first sub-wiring 510 is taken as an example for description. The first sub-wiring 510 includes a first part 500a, a second part 500b connected to the first part 500a, and a third part 500c connected to the first part 500a. The third part 500c includes a first section 500c1 connected to the second section 500b and a second section 500c2 connected to the first section 500c1.

[0048] like Figures 1 to 3 As shown, the insulating layer 600 has an opening to expose the first portion 500a of the wiring layer 500, and the insulating layer is formed on the second portion 500b and the third portion 500c of the wiring layer. In one embodiment, the protection electrode 800 is formed in the opening of the insulating layer 600 and contacts the first portion 500a of the wiring layer 500.

[0049] like Figure 3As shown, the second portion 500b is connected to the first portion 500a, and the second portion 500b includes a region that is partially in contact with the electrode of the light-emitting element. The third portion 500c is connected to the first portion 500a and extends from the first portion 500a to the edge of the unit pixel. In one embodiment, the edge of the first portion 500a extends to the edge of the unit pixel. In one embodiment, each sub-wiring has at least two third portions 500c extending to any two sides of the unit pixel.

[0050] In one embodiment, the wiring layer includes 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. In this embodiment, the wiring layer 500 includes a first layer 501 and a second layer 502, the first layer 501 is in direct contact with the light-emitting element, and the second layer 502 is formed on the first layer 501. Among them, the first layer 501 may include a first sublayer and a second sublayer, the first sublayer is used to adhere the second sublayer to the light-emitting element and the filling layer 400, and the second sublayer mainly plays a conductive role. The material of the first sublayer includes, but is not limited to, one or more of titanium, nickel, titanium nitride, tantalum nitride or tantalum, and the material of the second sublayer includes, but is not limited to, one or more of copper, aluminum or gold. The wiring layer 500 may be prepared by sputtering, evaporation or the like.

[0051] In one embodiment, if Figures 2 to 5 As shown, the first part 500a of the wiring layer 500 includes a first layer first sub-part 501a and a second layer first sub-part 502a, the second part 500b of the wiring layer 500 includes a first layer second sub-part 501b and a second layer second sub-part 502b, and the third part 500c of the wiring layer 500 includes a first layer third sub-part 501c and a second layer third sub-part 502c.

[0052] like Figure 4 As shown, the first layer 501 includes a first layer first sub-portion 501a, a first layer second sub-portion 501b and a first layer third sub-portion 501c, wherein the first layer first sub-portion 501a is connected to the first layer second sub-portion 501b and the first layer third sub-portion 501c respectively. The first layer third sub-portion 501c is connected to the first layer first sub-portion 501a and extends from the first layer first sub-portion 501a to the edge of the unit pixel.

[0053] The thickness of the first layer 501 is 0.05 μm to 1.5 μm, wherein the thickness of the first sub-layer is 10 nm to 200 nm, and the thickness of the second sub-layer is 200 nm to 1300 nm.

[0054] If the wiring layer 500 only includes the first layer 501, the thickness of the first layer 501 is only 0.05μm~1.5μm, the thickness is relatively thin, and the structural strength is relatively weak. The wiring layer 500 may have the risk of breaking during the use of the unit pixel. Therefore, the wiring layer 500 of the present invention forms the second layer 502 on the first layer 501, and the structural strength of the wiring layer 500 is increased by thickening the overall thickness of the wiring layer 500, thereby preventing the wiring layer 500 from having the risk of breaking during the use of the unit pixel. In a possible embodiment, the thickness of the second layer 502 is greater than 50% of the thickness of the first layer 501. If the thickness of the second layer 502 is less than 50% of the thickness of the first layer 501, the structural strength of the wiring layer 500 cannot be effectively enhanced. Preferably, the thickness of the second layer 502 is between 0.5μm~3μm. In a preferred embodiment, the thickness of the second layer 502 is greater than the thickness of the first layer 501. In one embodiment, the second layer 502 can be a metal such as Cu and Ni. In a preferred embodiment, the contact surface between the first layer 501 and the second layer 502 includes copper, and the contact surface between the second layer 502 and the first layer 501 includes copper, which can increase the bonding force between the second layer 502 and the first layer 501 located below the second layer 502 and avoid poor electrical contact.

[0055] By setting a second layer 502 which is 50% thicker than the first layer 502 on the first layer 501 of the wiring layer 500, the overall thickness of the wiring layer 500 is increased to strengthen the structural strength of the wiring layer 500. However, during the unitization process, the unit pixels need to be cut into unit pixels by laser or other equipment. During the cutting process, if the metal thickness of the wiring layer 500 increases, the number of cutting knives or the cutting power may increase exponentially; on the one hand, the increase in the number of knives may reduce the efficiency of pixel unitization and thus increase production costs; on the other hand, the increase in the number of cutting knives or the cutting power may cause thermal effects, so that the cutting path (i.e., the edge of the unit pixel) will have burn marks, affecting the yield of the product structure.

[0056] Figure 6 for Figure 4 A magnified schematic diagram of the local area A in the middle. Figure 7 for Figure 5 Enlarged schematic diagram of local area B in the middle.

[0057] In order to solve the above problem, in one embodiment, Figures 3 to 5 As shown, the first layer 501 is formed on the second layer 502, and the second layer 502 includes a second layer first sub-portion 502a formed on the first layer first sub-portion 501a, a second layer second sub-portion 502b formed on the first layer second sub-portion 501b, and a second layer third sub-portion 502c partially formed on the first layer third sub-portion 501c. Figure 6As shown, the first layer third sub-portion 501c includes a first region 501c1 connected to the first layer first sub-portion 501a and a second region 501c2 connected to the first region 501c1, and the second region 501c2 extends from the first region 501c1 to the edge of the unit pixel and to the edge of the unit pixel. Figure 7 As shown, the second layer third sub-portion 502c is formed on the first area 501c1, and the second layer third sub-portion 502c is not formed on the second area 501c2. In order to increase the structural strength of the wiring layer, the thickness of the second layer 502 needs to be greater than 50% of the thickness of the first layer 501, so that the wiring layer 500 may have sufficient structural strength to prevent the risk of disconnection. However, in order to avoid the influence of the pixel unitization process on the cutting, the thickness of at least part of the third part 500c is less than the thickness of the first part 500a, and the thickness of at least part of the third part 500c is less than the thickness of the second part 500b. Among them, the first layer third sub-portion 501c has a part close to the edge of the unit pixel and a part away from the edge of the unit pixel, and the second layer third sub-portion 502c is formed on the part away from the edge of the unit pixel. That is, the third part 500c includes a part close to the edge of the unit pixel and a part away from the edge of the unit pixel, and the thickness of the part close to the edge of the unit pixel is less than the thickness of the part away from the edge of the unit pixel. In one embodiment, the thickness of the third portion 500c near the edge of the unit pixel is smaller than the thickness of the first portion 500a, and the thickness of the third portion 500c near the edge of the unit pixel is smaller than the thickness of the second portion 500b.

[0058] In one embodiment, the thickness of the first portion 500a is between 1.5 μm and 4 μm, the thickness of the second portion 500b is between 1.5 μm and 4 μm, the thickness of the third portion 500c away from the edge of the unit pixel is between 1.5 μm and 4 μm, and the thickness of the third portion 500c close to the edge of the unit pixel is between 0.5 μm and 1.2 μm. The thicknesses of the first portion 500a, the second portion 500b, and the third portion 500c away from the edge of the unit pixel are equal, and are all greater than the thickness of the third portion 500c close to the edge of the unit pixel. By only increasing the thickness of the wiring layer away from the unit edge, the structural strength of the wiring layer 500 can be enhanced and the risk of disconnection can be reduced; the influence of the increase in the thickness of the wiring layer on the cutting during the pixel unitization process can also be avoided, thereby not affecting the yield of the unit pixel.

[0059] In one embodiment, the thickness of the wiring layer 500 including the first layer 501 and the second layer 502 is between 1.5 μm and 4 μm. If the thickness is less than 1.5 μm, the structural strength of the wiring layer 500 is insufficient to reduce the risk of wire breakage; if the thickness is greater than 4 μm, it is difficult to control the line width, thereby affecting the yield.

[0060] In one embodiment, if Figures 2 to 5 As shown, the third part 500c includes a first section 500c1 connected to the second part 500b and a second section 500c2 connected to the first section 500c1, and the second section 500c2 extends from the first section 500c1 to the edge of the unit pixel and to the edge of the unit pixel. The first section 500c1 includes a first layer 501 and a second layer 502 formed on the first layer 501, and the second section 500c2 is composed of the first layer 501, that is, the thickness of the first section 500c1 is greater than the thickness of the second section 500c2, so that while ensuring the structural strength of the wiring layer 500, the influence of the wiring layer close to the edge of the unit pixel (cutting road) on cutting during the pixel unitization process can be avoided as much as possible.

[0061] In one embodiment, the thickness of the first section 500c1 is between 1.5 μm and 4 μm, and the thickness of the second section 500c2 is between 0.5 μm and 1.2 μm.

[0062] In one embodiment, the thickness of the first section 500c1 is the same as the thickness of the first portion 500a and the second portion 500b. In other words, the thickness of the first portion 500a is greater than the thickness of the second section 500c2, and the thickness of the second portion 500a is greater than the thickness of the second section 500c2.

[0063] In one embodiment, the length of the first section 500c1 is less than 35um, and the length of the second section 500c2 is greater than 5um. During the pixel unitization process, a certain cutting path needs to be reserved between unit pixels. If the length of the second section 500c2 is less than 5μm, the thickening of the wiring layer 500 will affect it during the cutting process.

[0064] In one embodiment, the protective electrode 700 is formed on the first portion 500a, and the thickness of the protective electrode 700 is greater than the thickness of the first portion 500a. During the use of the unit pixel by the client, the protective electrode 700 is combined with the electrode pad of the display substrate by solder paste and other welding materials. The protective electrode 700 is greater than the thickness of the first portion 500a of the wiring layer, which can improve the welding reliability and prevent the increase of the thickness of the wiring layer 500 from causing the increase of the internal stress and affecting the bonding of the bottom metal in the wiring layer 500.

[0065] In one embodiment, if Figure 2 As shown, the wiring layer (500c2) extending to the edge of the unit pixel has a first thickness, and the portion of the wiring layer 500 (500b) located below the protective electrode 700 has a second thickness, and the first thickness is less than the second thickness. While ensuring the structural strength of the wiring layer 500, the influence of the wiring layer close to the unit pixel edge (cutting path) on cutting during the pixel unitization process is avoided as much as possible.

[0066] In one embodiment, the protective electrode 700 formed in the opening of the insulating layer 600 and in contact with the wiring layer 500 has a third thickness, the third thickness is greater than the first thickness, and the third thickness is greater than the second thickness. During the use of the unit pixel by the client, the protective electrode 700 is combined with the electrode pad of the display substrate by solder paste and other welding materials. The protective electrode 700 is greater than the thickness of the first part 500a of the wiring layer, which can improve the welding reliability and avoid the increase of the thickness of the wiring layer 500. The increase in internal stress can affect the bonding of the bottom metal in the wiring layer 500.

[0067] In one embodiment, if Figure 8 As shown, Figure 8 Schematic plan view of a unit pixel of another embodiment of the present application. The wiring layer 500 includes a first portion 500a, a second portion 500b connected to the first portion 500a, and a third portion 500c connected to the first portion 500a. A protective electrode 700 is formed on the first portion 500a and contacts the protective electrode 700. The second portion 500b is connected to the first portion 500a, and the second portion 500b includes a region that is partially in contact with the electrode of the light-emitting element. The third portion 500c is connected to the first portion 500a and extends from the first portion 500a to the edge of the unit pixel. The first portion 500a has a second thickness, the second portion 500b has a second thickness, and the third portion 500c has a first thickness. The second thickness is greater than the first thickness. The first portion 500a includes a first layer 501 and a second layer 502, the second portion 500b includes a first layer 501 and a second layer 502, and the third portion consists only of the first layer 501. The thickness of the second layer 502 is greater than 50% of the thickness of the first layer 501. The thickness of the first layer 501 is 0.05 μm to 1.5 μm, and the thickness of the second layer 502 is 0.5 μm to 3 μm. In a unit pixel of a smaller size, the distribution space of the wiring layer 500 is more limited. If the third part 500c is divided into a first section and a second section, the distribution space of the first section and the second section may be affected. Through the above structural design, the structural strength of the wiring layer 500 can be enhanced in a unit pixel of a smaller size, and at the same time, the influence of the wiring layer close to the unit pixel edge (cutting road) on the cutting during the pixel unitization process can be avoided as much as possible.

Claims

1. A unit pixel, include: A plurality of light emitting elements, wherein the plurality of light emitting elements are arranged at intervals; a wiring layer formed above the light emitting element and electrically connected to the light emitting element, the wiring layer comprising a first portion, a second portion connected to the first portion, and a third portion extending from the first portion to an edge of the unit pixel; an insulating layer formed on the wiring layer; Wherein, at least a portion of the third portion has a thickness smaller than that of the first portion, and at least a portion of the third portion has a thickness smaller than that of the second portion.

2. The unit pixel according to claim 1, It is characterized in that The insulating layer has an opening that exposes a first portion of the wiring layer.

3. The unit pixel according to claim 1, It is characterized in that The thickness of the first portion is between 1.5 μm and 4 μm, the thickness of the second portion is between 1.5 μm and 4 μm, and the thickness of part of the third portion is between 0.5 μm and 1.2 μm.

4. The unit pixel according to claim 1, It is characterized in that The third portion includes a portion close to an edge of a unit pixel and a portion far from the edge of the unit pixel, and a thickness of the portion close to the edge of the unit pixel is smaller than a thickness of the portion far from the edge of the unit pixel.

5. The unit pixel according to claim 4, It is characterized in that The thickness of the portion close to the edge of the unit pixel is between 0.5 μm and 1.2 μm, and the thickness of the portion far from the edge of the unit pixel is between 1.5 μm and 4 μm.

6. The unit pixel according to claim 1, It is characterized in that The third portion includes a first segment connected to the first portion and a second segment connected to the first segment, the second segment extends from the first segment to an edge of the unit pixel, and the thickness of the first segment is greater than that of the second segment.

7. The unit pixel according to claim 6, It is characterized in that The thickness of the second section is smaller than the thickness of the first portion and / or the second portion.

8. The unit pixel according to claim 6, It is characterized in that The length of the first segment is less than 35 um, and the length of the second segment is greater than 5 um.

9. The unit pixel according to claim 6, It is characterized in that The thickness of the first section is between 1.5 μm and 4 μm, and the thickness of the second section is between 0.5 μm and 1.2 μm.

10. The unit pixel according to claim 6, It is characterized in that The first section includes a first layer and a second layer formed on the first layer, the second section does not include the second layer, and a thickness of the second layer is greater than 50% of a thickness of the first layer.

11. The unit pixel according to claim 1, It is characterized in that The wiring layer includes a first layer and a second layer formed on a portion of the first layer, a surface of the first layer in contact with the second layer includes copper, and a surface of the second layer in contact with the first layer includes copper.

12. The unit pixel according to claim 2, It is characterized in that Also included is a protection electrode formed on the first portion.

13. The unit pixel according to claim 12, It is characterized in that The thickness of the protection electrode is greater than the thickness of the first portion.

14. A unit pixel, include: A plurality of light emitting elements, wherein the plurality of light emitting elements are arranged at intervals; A wiring layer, formed above the light emitting element and electrically connected to the light emitting element; an insulating layer formed on the wiring layer, the insulating layer having an opening portion exposing a portion of the surface of the wiring layer; A protection electrode is formed in the opening of the insulating layer and contacts the part of the wiring layer; The wiring layer includes a portion extending to an edge of a unit pixel having a first thickness and a portion located under the protection electrode having a second thickness, and the first thickness is smaller than the second thickness.

15. The unit pixel according to claim 14, It is characterized in that The thickness of the protection electrode is greater than the second thickness.

16. The unit pixel according to claim 14, It is characterized in that The wiring layer includes a first portion, a second portion connected to the first portion, and a third portion extending from the first portion to the edge of the unit pixel, the first portion has a second thickness, the second portion has a second thickness, and the third portion has a first thickness.

17. The unit pixel according to claim 16, It is characterized in that The opening of the insulating layer exposes the first portion of the wiring layer, and the protection electrode is formed on the first portion of the wiring layer.

18. The unit pixel according to claim 16, It is characterized in that The first portion includes a first layer and a second layer formed on the first layer, the second portion includes a first layer and a second layer formed on the first layer, and the third portion does not include the second layer.

19. The unit pixel according to claim 18, It is characterized in that The thickness of the first layer is 0.05 μm to 1.5 μm, and the thickness of the second layer is 0.5 μm to 3 μm.

20. The unit pixel according to any one of claims 1 to 19, It is characterized in that It also includes a transparent layer, a transfer layer, and a filling layer. The light-emitting element is arranged on the transparent layer, the transfer layer is located between the transparent layer and the light-emitting element, and the filling layer is arranged between adjacent light-emitting elements.

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