Unit pixel and display device

Abstract

Provided in the present application is a unit pixel, comprising a plurality of light-emitting elements arranged at intervals. At least one of the light-emitting elements comprises: a semiconductor stack, which comprises a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence; an insulating layer, which covers the semiconductor stack, wherein the insulating layer comprises a plurality of openings, the plurality of openings including a first opening and a second opening; and electrode pads, which include a first electrode pad and a second electrode pad, the first electrode pad being electrically connected to the first semiconductor layer through the first opening, and the second electrode pad being electrically connected to the second semiconductor layer through the second opening. A wiring layer is located on the light-emitting elements and electrically connected to the light-emitting elements; the electrode pads of the light-emitting elements each comprise a contact region for coming into contact through an opening of the insulating layer, and the wiring layer comes into at least partial contact with the contact region of each of the electrode pads of the light-emitting elements.

Description

Unit pixel and display device Technical Field

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

[0002] Due to their high reliability, long lifespan, and low power consumption, LED chips are widely used in a variety of fields, including display devices, automotive lighting, and general lighting. For example, RGB LED chips can be used as unit pixels in various display devices. Currently, the tiny chips (micro-LED chips, generally less than 100nm) are too small to be easily attached to the display panel. Therefore, the three RGB chips are packaged into a single unit pixel, which simplifies the process of attaching the unit pixel to the display panel.

[0003] However, the reliability of existing unit pixel packages is relatively poor, and how to obtain a unit pixel with high reliability remains a difficult problem. Technical Solutions

[0004] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a unit pixel and a display device to improve the light-emitting effect and reliability.

[0005] In order to achieve the above-mentioned object and other related objects, the present invention provides a unit pixel, comprising: a plurality of light-emitting elements arranged at intervals, wherein at least one of the light-emitting elements comprises: a semiconductor stack, comprising a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence; an insulating layer, covering the semiconductor stack, the insulating layer comprising a plurality of openings, the plurality of openings comprising a first opening and a second opening; an electrode pad, comprising a first electrode pad and a second electrode pad, the first electrode pad being electrically connected to the first semiconductor layer through the first opening, and the second electrode pad being electrically connected to the second semiconductor layer through the second opening; a wiring layer, located above the light-emitting element and electrically connected to the light-emitting element; wherein the electrode pad of the light-emitting element comprises a contact area that contacts the insulating layer opening, and the wiring layer is at least partially in contact with the electrode pad contact area of ​​the light-emitting element. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0007] FIG1 is a schematic plan view of a display device according to an embodiment of the present invention;

[0008] FIG2 is a schematic plan view of a unit pixel according to an embodiment of the present invention;

[0009] FIG3 is a schematic cross-sectional view taken along the section line AA′ of FIG2 ;

[0010] FIG4 is a partial enlarged schematic diagram of FIG3;

[0011] FIG5 is a schematic plan view of a light emitting element according to an embodiment of the present invention;

[0012] FIG. 6 is a schematic cross-sectional view taken along the cutting line BB′ of FIG. 5 .

[0013] FIG7 is a schematic plan view of a unit pixel according to another embodiment of the present invention;

[0014] FIG8 is a schematic plan view of a unit pixel according to another embodiment of the present invention;

[0015] FIG9 is a schematic cross-sectional view taken along the section line C-C′ of FIG8 ;

[0016] FIG10 is a partial enlarged schematic diagram of FIG9;

[0017] FIG11 is a schematic structural diagram showing the formation of a filling layer according to another embodiment of the present invention;

[0018] FIG. 12 is a schematic structural diagram showing the formation of a wiring layer according to another embodiment of the present invention. Modes for Carrying Out the Invention

[0019] The following specific embodiments illustrate the embodiments of the present invention. Those skilled in the art will readily appreciate the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different perspectives and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features of the embodiments may be combined with each other unless they conflict.

[0020] It should be noted that the diagrams provided in the embodiments of the present invention are only schematic illustrations of the basic concept of the present invention. Although the diagrams only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation, the form, quantity, and proportion of each component in actual implementation can be changed at will, and the component layout form 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 conditions for the implementation of this application. Therefore, they have no technical 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 efficacy and purpose of the present invention.

[0021] In the existing technology, a unit pixel includes at least three light-emitting elements, which emit red light, green light, and blue light respectively, and contact the electrode pads of the light-emitting elements through the wiring layer to electrically connect them and reorganize the circuits of the three light-emitting elements. On the one hand, there is no need for wire bonding, which can effectively improve the area ratio of the light-emitting element to the unit pixel. On the other hand, the number of pads of the unit pixel can be minimized by wiring layer reorganization. At the same time, the pads are expanded to the area outside the light-emitting element on the unit pixel, increasing the size of a single pad, reducing the circuit design of the back-end application, facilitating the back-end patch, and can simply and effectively reduce the size of the package. However, since the size of the light-emitting element in this application is less than 100μm×100μm, the size of the insulating layer opening is smaller than that of the insulating layer opening of a conventional light-emitting element, resulting in a steeper sidewall of the insulating layer opening, which causes the electrode pad formed on the insulating layer opening to have cracks and poor electrical contact. The wiring layer contacts the electrode pad of the light-emitting element, which may cause the circuit of the unit pixel reorganization to be open or short-circuited.

[0022] In order to solve the above problems, the present application provides a unit pixel, including:

[0023] A plurality of light-emitting elements arranged at intervals, wherein at least one of the light-emitting elements comprises: a semiconductor stack comprising a first semiconductor layer, an active layer, and a second semiconductor layer stacked in sequence; an insulating layer covering the semiconductor stack, the insulating layer comprising a plurality of openings, the plurality of openings comprising a first opening and a second opening; and electrode pads comprising a first electrode pad and a second electrode pad, the first electrode pad being electrically connected to the first semiconductor layer through the first opening, and the second electrode pad being electrically connected to the second semiconductor layer through the second opening;

[0024] a wiring layer, located above the light-emitting element and electrically connected to the light-emitting element;

[0025] The electrode pad of the light-emitting element includes a contact area that contacts the opening of the insulating layer, and the wiring layer is in at least partial contact with the contact area of ​​the electrode pad of the light-emitting element. Optionally, a transparent layer is further included, and the multiple light-emitting elements are spaced apart on the transparent layer. The contact area of ​​the electrode pad of the light-emitting element includes a first area and a second area, the first area being the area where the first electrode pad of the light-emitting element contacts the first opening of the insulating layer, and the second area being the area where the second electrode pad of the light-emitting element contacts the second opening of the insulating layer.

[0026] Optionally, a filling layer is further included, which is filled between adjacent light-emitting elements. Taking the transparent layer as a reference, the surface of the filling layer away from the transparent layer is lower than the highest surface of the electrode pad of the light-emitting element, or the surface of the filling layer away from the transparent layer is higher than the highest surface of the electrode pad of the light-emitting element.

[0027] Optionally, the filling layer includes a plurality of openings exposing electrode pads of the light-emitting element.

[0028] Optionally, at least one or more openings of the filling layer expose a contact region of the electrode pad of the light-emitting element, and the wiring layer partially contacts the contact region of the electrode pad of the light-emitting element through the opening of the filling layer.

[0029] Optionally, in a projection direction perpendicular to the transparent layer, a projection area of ​​at least one or more openings of the filling layer is larger than a projection area of ​​the first opening and / or the second opening of at least one light-emitting element insulating layer.

[0030] Optionally, in a projection direction perpendicular to the transparent layer, the projection of at least one or more openings of the filling layer at least partially overlaps with the projection of at least one first opening and / or second opening of the light-emitting element insulating layer.

[0031] Optionally, the wiring layer includes a first wiring layer, a second wiring layer, a third wiring layer and a fourth wiring layer, 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, the second light-emitting element and the third light-emitting element respectively include the first electrode pad and the second electrode pad, the first wiring layer is electrically connected to the first electrode pad of the first light-emitting element, the second light-emitting element and the third light-emitting element, the second wiring layer is electrically connected to the second electrode pad of the first light-emitting element, the third wiring layer is electrically connected to the second electrode pad of the second light-emitting element, and the fourth wiring layer is electrically connected to the second electrode pad of the third light-emitting element.

[0032] Optionally, the filling layer opening portion includes a first opening portion, a second opening portion, a third opening portion, a fourth opening portion, a fifth opening portion and a sixth opening portion, the first opening portion at least partially exposes the first area of ​​the first electrode pad of the first light-emitting element, the second opening portion at least partially exposes the second area of ​​the second electrode pad of the first light-emitting element, the third opening portion at least partially exposes the first area of ​​the first electrode pad of the second light-emitting element, the fourth opening portion at least partially exposes the second area of ​​the second electrode pad of the second light-emitting element, the fifth opening portion at least partially exposes the first area of ​​the first electrode pad of the third light-emitting element, and the sixth opening portion at least partially exposes the second area of ​​the second electrode pad of the third light-emitting element.

[0033] Optionally, the first wiring layer includes a first area portion contacting the first electrode pads of the first light-emitting element, the second light-emitting element and the third light-emitting element through the first opening portion, the third opening portion and the fifth opening portion, the second wiring layer is in contact with the second area portion of the second electrode pad of the first light-emitting element through the second opening portion, the third wiring layer is in contact with the second area portion of the second electrode pad of the second light-emitting element through the fourth opening portion, and the fourth wiring layer is in contact with the second area portion of the second electrode pad of the third light-emitting element through the sixth opening portion.

[0034] Optionally, the opening of the filling layer is elliptical or circular.

[0035] Optionally, there is no filling layer on the surface of the light emitting element electrode pad.

[0036] Optionally, in a projection direction perpendicular to the transparent layer, a projection of a contact area of ​​at least one of the light-emitting element electrode pads partially overlaps with a projection of the wiring layer.

[0037] Optionally, in a projection direction perpendicular to the transparent layer, a projection of a contact area of ​​at least one of the light-emitting element electrode pads is located within a projection of the wiring layer.

[0038] Optionally, in a projection direction perpendicular to the transparent layer, a projection of at least one of the light-emitting element electrode pads is located within a projection of the wiring layer.

[0039] Optionally, the wiring layer is in complete contact with the electrode pad contact region of the light emitting element.

[0040] Optionally, there is a minimum distance between the first wiring layer partially formed on the first light-emitting element and the second wiring layer partially formed on the first light-emitting element, or there is a minimum distance between the first wiring layer partially formed on the second light-emitting element and the third wiring layer partially formed on the second light-emitting element, or there is a minimum distance between the first wiring layer partially formed on the third light-emitting element and the fourth wiring layer partially formed on the third light-emitting element, and the minimum distance is between 1 and 50 μm.

[0041] Optionally, the minimum width of the wiring layer is not less than 1-50 μm.

[0042] Optionally, the contact area between the wiring layer and the light emitting element electrode pad contact region accounts for at least 50% of the area of ​​the light emitting element electrode pad contact region.

[0043] Yet another aspect of the present application provides a display device, including a panel substrate, and a plurality of pixel modules fixed to the panel substrate, wherein the pixel modules include the unit pixels provided in the present application.

[0044] The display device includes the above-mentioned unit pixel provided in the present application, and thus has good display effect and reliability.

[0045] FIG. 1 is a schematic plan view of a display device according to an embodiment of the present invention.

[0046] 1 , a display device 10000 may include a panel substrate 2100 and a plurality of pixel modules 1000 .

[0047] The display device 10000 is not particularly limited and may include a micro LED TV, a smart watch, a VR display device such as a VR head-mounted device, or an AR display device such as augmented reality glasses.

[0048] The panel substrate 2100 may include circuits for passive matrix driving or active matrix driving. In one embodiment, the panel substrate 2100 may include wiring and resistors internally. In another embodiment, the panel substrate 2100 may include wiring, transistors, and capacitors. The panel substrate 2100 may also have pads on its upper surface that can be electrically connected to the arranged circuits.

[0049] In one embodiment, a plurality of pixel modules 1000 are neatly arranged on a panel substrate 2100. Each pixel module 1000 may include a circuit substrate 1001 and a plurality of unit pixels 100 disposed on the circuit substrate 1001. In another embodiment, the plurality of unit pixels 100 may also be directly arranged on the panel substrate 2100.

[0050] FIG2 is a schematic plan view of a unit pixel 100 according to an embodiment, FIG3 is a schematic cross-sectional view taken along the cutting line AA′ of FIG2 , and FIG4 is a partially enlarged schematic view of FIG3 .

[0051] This embodiment provides a unit pixel, as shown in Figure 2, which includes a transparent layer 100, a plurality of light-emitting elements arranged at intervals on the transparent layer 100, a filling layer 300 filled between adjacent light-emitting elements, a wiring layer 400 located above the light-emitting elements and the filling layer 300 and electrically connected to the light-emitting elements, and an insulating protective layer 500 located above the wiring layer 400.

[0052] 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, which may be a light-transmitting substrate such as PET, glass, quartz, sapphire, or transparent ceramic. 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 provided 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.

[0053] The unit pixel 100 includes a plurality of light-emitting elements 10a, 10b, and 10c. The light-emitting elements 10a, 10b, and 10c can emit light of different colors. The light-emitting elements 10a, 10b, and 10c within each unit pixel 100 can be arranged in a row as shown in FIG1 . In one embodiment, the light-emitting elements 10a, 10b, and 10c can be arranged vertically relative to a display screen that realizes an image. However, the present invention is not limited to this, and the light-emitting elements 10a, 10b, and 10c can also be arranged horizontally relative to the display screen that realizes an image.

[0054] In an optional embodiment, the light-emitting element primarily refers to a micron-sized light-emitting diode, with a width and length ranging from 2 μm to 5 μm, 5 μm to 10 μm, 10 μm to 20 μm, 20 μm to 50 μm, or 50 μm to 100 μm, and a thickness ranging from 2 μm to 15 μm, or further from 5 μm to 10 μm. In this embodiment, the unit pixel 100 includes a first light-emitting element 10a, a second light-emitting element 10b, and a third light-emitting element 10c. Each light-emitting element also includes a first electrode pad 41 and a second electrode pad 42.

[0055] 2 , a filling layer 300 fills the gaps between adjacent light-emitting elements or is formed around the sidewalls of each light-emitting element to electrically isolate adjacent light-emitting elements while preventing color mixing or light interference between adjacent light-emitting elements, thereby improving the contrast of the unit pixel 100. The filling layer 300 is provided as a black glue layer that absorbs light.

[0056] Since the thickness of the light-emitting element ranges from 2 to 15 μm, and the spacing between adjacent light-emitting elements is less than 50 μm, a material with good fluidity is used for filling and then solidifying when forming the filling layer 300. The particle size of the black filling component filled in the filling layer 300 is preferably no greater than 1 / 10 of the thickness of the light-emitting element, which can avoid the problem of poor coverage of the filling layer 300 on the light-emitting element due to the excessive particle size of the black filling component, thereby affecting the contrast of the unit pixel 100. The filling layer 300 can specifically be a component formed by dispersing a black filling component with a particle size no 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 300 includes, but is not limited to, carbon black, titanium nitride, iron oxide, ferroferric oxide, iron powder, etc. The particle size of the black filling component is preferably in the range of 10-100 nm, or 100-200 nm, or 200-300 nm, or 300 nm-500 nm. The filling layer 300 may also be made of black dye.

[0057] To prevent color mixing or interference between adjacent light-emitting elements, the filling layer 300 covers at least the active layer of the light-emitting element and, further, covers all sidewalls of the light-emitting element. Alternatively, the thickness of the filling layer 300 can be greater than that of the light-emitting element to prevent light leakage from the bottom of the light-emitting element and cause optical interference. The thickness of the filling layer 300 is preferably less than 15 μm.

[0058] In one embodiment, as shown in FIG4 , with the transparent layer 100 as a reference, a surface 300s of the filling layer 300 away from the transparent layer 100 is lower than the highest surface 40s of the electrode pad of the light-emitting element, that is, the filling layer 300 only covers the sidewalls of the light-emitting element, and the highest surfaces 50s of the first electrode pad 41 and the second electrode pad 42 of the light-emitting element are directly exposed.

[0059] 2 and 3 again, the wiring layer 400 is formed over the plurality of light emitting elements and the filling layer 300 and is in contact with the electrode pads of the light emitting elements.

[0060] The wiring layer 400 includes several sub-wiring layers. In an alternative embodiment, as shown in FIG3 , the wiring layer 400 includes a first wiring layer 410, a second wiring layer 420, a third wiring layer 430, and a fourth wiring layer 440. The first wiring layer 410 serves as a common wiring layer, connecting the first electrode pad 41 of the first light-emitting element 10 a, the second light-emitting element 10 b, and the third light-emitting element 10 c in series. The second electrode pad 42 of the first light-emitting element 10 a is connected to the second wiring layer 420, the second electrode pad 42 of the second light-emitting element 10 b is connected to the third wiring layer 430, and the second electrode pad 42 of the third light-emitting element 10 c is connected to the fourth wiring layer 440.

[0061] Alternatively, the first wiring layer 410 serves as a common wiring, connecting the second electrode pads 42 of the first light-emitting element 10a, the second light-emitting element 10b and the third light-emitting element 10c in series, the first electrode pad 41 of the first light-emitting element 10a is connected to the second wiring layer 420, the first electrode pad 41 of the second light-emitting element 10b is connected to the third wiring layer 430, and the first electrode pad 41 of the third light-emitting element 10c is connected to the fourth wiring layer 440.

[0062] The wiring layer 400 can be a single-layer or multi-layer structure made of at least one material selected from titanium, copper, chromium, nickel, gold, platinum, aluminum, titanium nitride, tantalum nitride, or tantalum, prepared by sputtering, evaporation, or the like. In this embodiment, the wiring layer 400 is a composite metal layer formed of Ti and Cu, and the thickness of the wiring layer 400 ranges from 50 nm to 1000 nm, for example, 100 nm, 200 nm, 500 nm, 600 nm, 800 nm, etc. The material selection for the wiring layer 400 ensures good adhesion to the filling layer 300, and the thickness is set to ensure good growth of the conductive pads while achieving good electrical connection with the light-emitting element.

[0063] FIG5 is a schematic plan view of a light-emitting element 10a according to an embodiment of the present invention, and FIG6 is a schematic cross-sectional view taken along line BB' in FIG5 . Here, light-emitting element 10a is used as an example for description. However, since light-emitting elements 10b and 10c have substantially similar structures, redundant descriptions thereof will be omitted.

[0064] As shown in the figure, the light emitting element 10 a may include a semiconductor stack including a first semiconductor layer 21 , an active layer 22 and a second semiconductor layer 23 , an insulating layer 30 formed on the semiconductor stack, and a first electrode pad 41 and a second electrode pad 42 formed on the insulating layer 30 .

[0065] When viewed in plan, light-emitting element 10a may have a rectangular shape with a major axis and a minor axis. For example, the major axis may be less than 100 μm, and the minor axis may be less than 70 μm. Light-emitting elements 10a, 10b, and 10c may have substantially similar shapes and sizes.

[0066] The semiconductor stack (i.e., the first semiconductor layer 21, the active layer 22, and the second semiconductor layer 23) can be grown on a substrate. The substrate can be a gallium nitride substrate, a gallium arsenide (GaAs) substrate, a silicon (Si) substrate, a sapphire substrate, and in particular, a patterned sapphire substrate can be used as a variety of substrates for semiconductor growth. The growth substrate can be separated from the semiconductor layer using mechanical grinding, laser lift-off, chemical lift-off, and other techniques. However, the present invention is not limited to this, and a portion of the substrate can also be left to constitute at least a portion of the first semiconductor layer 21.

[0067] The first semiconductor layer 21 and the second semiconductor layer 23 have opposite polarities. When the first semiconductor layer 21 is n-type, the second semiconductor layer 23 is p-type, and when the first semiconductor layer 21 is p-type, the second semiconductor layer 23 is n-type.

[0068] The first semiconductor layer 21, the active layer 22, and the second semiconductor layer 23 can be grown on the substrate in a chamber using a well-known method such as metal organic chemical vapor deposition (MOCVD). Furthermore, the first semiconductor layer 21 includes n-type impurities (e.g., Si, Ge, Sn), and the second semiconductor layer 23 includes p-type impurities (e.g., Mg, Sr, Ba). In one embodiment, the first semiconductor layer 21 may include GaN or AlGaN containing Si as a dopant, and the second semiconductor layer 23 may include GaN or AlGaN containing Mg as a dopant.

[0069] Although the first semiconductor layer 21 and the second semiconductor layer 23 are shown as single layers in the drawings, these layers can be multiple layers and can also include a superlattice layer. The active layer 22 can include a single quantum well structure or a multiple quantum well structure, and the composition ratio of the nitride-based semiconductor can be adjusted to emit a desired wavelength. For example, the active layer 22 can emit blue light, green light, red light, or ultraviolet light.

[0070] The semiconductor stack is patterned by photolithography, etching, and other methods to form a semiconductor platform P and a mesa M. The mesa M is formed by removing portions of the second semiconductor layer 23 and the active layer 22 to expose a portion of the surface of the first semiconductor layer 21. The semiconductor platform P generally includes a structure of the first semiconductor layer 201, the second semiconductor layer 202, and the active layer 203.

[0071] As shown in FIG6 , at least one of the first semiconductor layers 21 of the light-emitting element 10a may have an inclined side surface. The inclined side surface of the first semiconductor layer 21 may be formed by an element separation process. The side surface of the first semiconductor layer 21 may be inclined at an angle of about 40 degrees to about 80 degrees relative to the bottom surface of the first semiconductor layer 21. The semiconductor platform P may also have an inclined side surface, and the inclination angle relative to the bottom surface of the semiconductor platform P may be in a range of about 40 degrees to about 80 degrees. Since the first semiconductor layer 21 and the semiconductor platform P have inclined side surfaces, the insulating layer 30 described later can be easily formed.

[0072] An insulating layer 30 is formed on and covers the semiconductor stack. The insulating layer 30 includes a first opening and a second opening. The insulating layer 30 may include a distributed Bragg reflector (DBR) comprising stacked insulating layers having different refractive indices. For example, the DBR may include at least two insulating layers selected from SiO2, Si3N4, SiON, TiO2, Ta2O5, Nb2O5, MgF2, and the like. The DBR may include, for example, multiple pairs of low-refractive-index layers and high-refractive-index layers. For example, the DBR may include more than ten pairs of low-refractive-index layers and high-refractive-index layers.

[0073] The distributed Bragg reflector reflects light emitted from the active layer 22. The distributed Bragg reflector can exhibit high reflectivity over a relatively wide wavelength range, including the peak wavelength of light emitted from the active layer 22, and can be designed in consideration of the incident angle of the light. In one embodiment, the distributed Bragg reflector can have a higher reflectivity for light incident at an incident angle of 0 degrees than for light incident at other incident angles. In another embodiment, the distributed Bragg reflector can have a higher reflectivity for light incident at other specific incident angles than for light incident at an incident angle of 0 degrees. For example, the distributed Bragg reflector can have a higher reflectivity for light incident at an incident angle of 10 degrees than for light incident at an incident angle of 0 degrees.

[0074] The first electrode pad 41 and the second electrode pad 42 are disposed on the insulating layer 30. The first electrode pad 41 can be electrically connected to the first semiconductor layer 21 through the first opening OP1, and the second electrode pad 42 can be electrically connected to the second semiconductor layer 23 through the second opening OP2.

[0075] In one embodiment, referring to FIG5 , the electrode pad includes a contact region that contacts the insulating layer opening, and the contact region includes a first region 41 a and a second region 42 a. The first electrode pad 41 includes a first region 41 a that contacts the first opening OP1 of the insulating layer 30. The first electrode pad 41 is electrically connected to the first semiconductor layer 21 of the light-emitting element via the first region 41 a. The second electrode pad 42 includes a second region 42 a that contacts the second opening OP2 of the insulating layer 30. The second electrode pad 42 is electrically connected to the second semiconductor layer 23 of the light-emitting element via the second region 42 a. The projection of the first region 41 a in a direction perpendicular to the semiconductor stack overlaps with the projection of the first opening OP1 in the direction perpendicular to the semiconductor stack. The projection of the second region 42 a in a direction perpendicular to the semiconductor stack overlaps with the projection of the second opening OP2 in the direction perpendicular to the semiconductor stack.

[0076] The first electrode pad 41 and / or the second electrode pad 42 may be formed of a single layer or multiple layers of metal, such as Al, Ti, Cr, Ni, Au, or alloys thereof.

[0077] Since the size of the light-emitting element in the present application is less than 100μm×100μm, the sizes of the first opening OP1 and the second opening OP2 of the insulating layer 30 are smaller than those of the insulating layer openings of conventional light-emitting elements, resulting in the sidewalls of the first opening OP1 or the second opening OP2 being relatively steep, and the thickness of the first electrode pad 41 or the second electrode pad 42 of the light-emitting element is only 1~2μm, and a good coating cannot be formed on the steep sidewalls of the insulating layer opening, which can easily cause cracks to be generated at the first opening OP1 or the second electrode pad 42 formed on the second opening OP2, which may cause poor electrical contact.

[0078] As shown in Figures 2, 3 and 4, the surface 40s of the electrode pad of the light-emitting element is not covered by the filling layer 300, and the wiring layer 400 is in at least partial contact with the contact area of ​​the electrode pad, which can not only make the wiring layer 400 electrically connected to the light-emitting element, but also prevent the problem of poor contact between the wiring layer 400 and the light-emitting element due to cracks between the electrode pad of the light-emitting element and the opening of the insulating layer 30, thereby improving the reliability of the unit pixel. If the contact area of ​​the light-emitting element electrode pad has poor electrical properties at the opening of the insulating layer, the wiring layer 400 only contacts the non-contact area of ​​the light-emitting element electrode pad, and the unit pixel 100 may be at risk of open circuit or short circuit. In a preferred embodiment, the contact area of ​​the wiring layer 400 and the light-emitting element electrode pad is at least 50% of the area of ​​the light-emitting element electrode pad contact area.

[0079] In one embodiment, the first wiring layer 410 serves as a common wiring, and the first electrode pads 41 in the first, second, and third light-emitting elements 10a, 10b, and 10c are electrically connected to the first wiring layer 410. In a projection direction perpendicular to the transparent layer, the projection of the first wiring layer 410 at least partially overlaps with the first electrode pads 41 in the first, second, and third light-emitting elements 10a, 10b, and 10c. Because the electrode pads of the light-emitting elements are completely exposed by the filling layer 300, the overlapping area between the projections of the first wiring layer 410 and the first electrode pads 41 in the first, second, and third light-emitting elements 10a, 10b, and 10c serves as a contact area. To prevent cracks from forming between the first electrode pads 41 in the first, second, and third light-emitting elements 10a, 10b, and 10c and the first opening OP1 in the insulating layer 30, which could result in poor contact between the wiring layer 400 and the light-emitting elements, the first wiring layer 410 at least partially contacts the first region of the first electrode pad 41. The above design can not only electrically connect the first wiring layer to the first light-emitting element 10a, the second light-emitting element 10b, or the third light-emitting element 10c, but also prevent the problem of poor contact between the first wiring layer and each light-emitting element due to cracks between the first electrode pad in the first light-emitting element 10a, the second light-emitting element 10b, and the third light-emitting element 10c and the first opening of the insulating layer.

[0080] Figure 7 is a schematic plan view of a unit pixel according to another embodiment of the present invention. In a preferred embodiment, as shown in Figure 7 , in a projection direction perpendicular to the transparent layer 300, the projection of the first region 41a of the first electrode pad 41 is located within the projection of the first wiring layer 410, i.e., the first wiring layer 410 is in full contact with the first region 41a of the first electrode pad 41.

[0081] In another preferred embodiment, not shown in the figure, in the projection direction perpendicular to the transparent layer, the projection of the first electrode pad is located within the projection of the first wiring layer, that is, the first wiring layer 410 is in complete contact with the first electrode pad.

[0082] In one embodiment, referring again to FIG. 2 , the second wiring layer 420 is electrically connected to the second electrode pad 42 of the first light-emitting element 10a. The second wiring layer 420 at least partially overlaps with the second region 42a of the second electrode pad 42 of the first light-emitting element 10a. In a preferred embodiment, the projection of the second region 42a of the second electrode pad 42 is located within the projection of the second wiring layer 420 in a direction perpendicular to the projection of the transparent layer 300. That is, the second wiring layer 420 is in full contact with the second region 42a of the second electrode pad 42. In another preferred embodiment, the projection of the second electrode pad 42 is located within the projection of the second wiring layer 420 in a direction perpendicular to the projection of the transparent layer 300. That is, the second wiring layer 420 is in full contact with the second electrode pad 42. This design not only ensures electrical connection between the second wiring layer 420 and the first light-emitting element 10a, but also prevents poor contact between the second wiring layer 420 and the first light-emitting element 10a due to cracks between the second electrode pad 42 of the first light-emitting element 10a and the second opening OP2 of the insulating layer.

[0083] Similarly, in one embodiment, the third wiring layer 430 is electrically connected to the second electrode pad 42 of the second light-emitting element 10b. The third wiring layer 430 at least partially overlaps with the second region 42a of the second electrode pad 42 of the second light-emitting element 10b. In a preferred embodiment, the projection of the second region 42a of the second electrode pad 42 is located within the projection of the third wiring layer 430 in a direction perpendicular to the projection of the transparent layer 300. That is, the third wiring layer 430 is in full contact with the second region 42a of the second electrode pad 42. In another preferred embodiment, the projection of the second electrode pad 42 is located within the projection of the third wiring layer 430 in a direction perpendicular to the projection of the transparent layer 300. That is, the third wiring layer 430 is in full contact with the second electrode pad 42. This design not only ensures electrical connection between the third wiring layer 430 and the second light-emitting element 10b, but also prevents poor contact between the third wiring layer 430 and the second light-emitting element 10b due to cracks between the second electrode pad 42 of the second light-emitting element 10b and the second opening OP2 of the insulating layer.

[0084] In one embodiment, the fourth wiring layer 440 is electrically connected to the second electrode pad 42 of the third light-emitting element 10c. The fourth wiring layer 440 at least partially overlaps with the second region 42a of the second electrode pad 42 of the third light-emitting element 10c. In a preferred embodiment, the projection of the second region 42a of the second electrode pad 42 is located within the projection of the fourth wiring layer 440 in a direction perpendicular to the projection of the transparent layer 300. That is, the fourth wiring layer 440 is in full contact with the second region 42a of the second electrode pad 42. In another preferred embodiment, the projection of the second electrode pad 42 is located within the projection of the fourth wiring layer 440 in a direction perpendicular to the projection of the transparent layer 300. That is, the fourth wiring layer 440 is in full contact with the second electrode pad 42. This design not only ensures electrical connection between the fourth wiring layer 440 and the third light-emitting element 10c, but also prevents poor contact between the fourth wiring layer 440 and the third light-emitting element 10c due to cracks between the second electrode pad 42 of the third light-emitting element 10c and the second opening OP2 of the insulating layer.

[0085] In one embodiment, as shown in the figure, the shortest distance L1 between the first wiring layer 410 and the second wiring layer 420 formed on the first light-emitting element 10a is between 1 and 50 μm. If the shortest distance L1 is too small, a short circuit may occur between the first wiring layer 410 and the second wiring layer 420. Similarly, the shortest distance L1 between the first wiring layer 410 and the third wiring layer 430 formed on the second light-emitting element is also between 1 and 50 μm, and the shortest distance L1 between the first wiring layer 410 and the fourth wiring layer 440 formed on the third light-emitting element 10c is also between 1 and 50 μm.

[0086] In one embodiment, the width of the wiring layer 400 is between 1 μm and 50 μm.

[0087] 2 and 3 again, the insulating protective layer 500 is located on the upper surface of the wiring layer 400 and fills the periphery of the wiring in the wiring layer 400. The insulating protective layer 500 defines an opening 500a above the wiring layer 400. The unit pixel can be mounted on the circuit substrate using the wiring layer 400 through the opening 500a and a bonding material such as solder.

[0088] The insulating protection layer 500 may be formed of materials such as epoxy resin, polysiloxane or photoresist, which can prevent the wiring layer 400 from being oxidized and electrically isolate different wirings to avoid leakage failure of unit pixels.

[0089] Referring again to Figures 2 and 3 , the unit pixel of this embodiment further includes an adhesive layer 200, which is positioned between the transparent layer 300 and the light-emitting element, allowing the light-emitting element to adhere to the transparent layer 300 via the adhesive layer 200. The adhesive layer 200 may completely cover the entire surface of the transparent layer 300, but is not limited thereto. Alternatively, the adhesive layer 200 may be positioned only below the light-emitting element, allowing the light-emitting element to adhere to the transparent layer 300 via the adhesive layer 200. Because different light-emitting elements typically have different thicknesses, providing the adhesive layer 200 between the transparent layer 300 and the light-emitting element can reduce height differences between the light-emitting elements, allowing light emitted from the sides of the light-emitting element to be absorbed by the filling layer 300 as much as possible, thereby improving the contrast of the unit pixel 100. The thickness of the adhesive layer 200 ranges from 1 μm to 15 μm, or from 3 μm to 10 μm.

[0090] Referring again to Figures 2 and 3, the unit pixel of this embodiment further includes a protective electrode 600. When the material forming the wiring layer 400 is easily oxidized, for example, in one embodiment, when the surface metal of the wiring layer 400 is Cu, the wiring layer exposed by the opening of the insulating protective layer 500 is easily oxidized. Therefore, a protective electrode 600 can be formed at the opening of the insulating protective layer 500 to protect the exposed wiring layer 400. A plurality of protective electrodes 600 are formed on the exposed wiring layer 400 to form an electrical connection with the wiring layer 400.

[0091] In one embodiment, the material of the protective electrode 600 can be one or more of nickel, gold, platinum, or chromium, tin, or palladium. The thickness of the protective electrode 600 is between 1 and 6 μm, for example, 2 μm, 3 μm, 4 μm, 5 μm, etc.

[0092] In one embodiment, the protective electrode 600 includes a first layer structure and a second layer structure, wherein the thickness of the first layer structure is greater than that of the second layer structure. In a preferred embodiment, the first layer structure may be a nickel layer, and the second layer structure may be a gold layer. The thickness of the first layer structure is 2μm to 5μm, and the thickness of the second layer structure is 20 Å to 50 Å. This thickness ratio can achieve good flatness. In one embodiment, the wiring layer 400 includes copper metal. For example, when the surface metal is copper, a portion of the copper metal contacts the insulating protective layer 500, while a portion of the copper metal is exposed by the opening of the insulating protective layer 500, thereby contacting the protective electrode 600 and being protected by the protective electrode 600 to prevent oxidation.

[0093] FIG8 is a schematic cross-sectional view for illustrating a unit pixel according to another embodiment, FIG9 is a schematic cross-sectional view taken along the cutting line C-C' of FIG8 , FIG10 is a partially enlarged schematic view of FIG9 , FIG11 is a structural schematic view showing the formation of a filling layer according to another embodiment of the present invention, and FIG12 is a structural schematic view showing the formation of a wiring layer according to another embodiment of the present invention.

[0094] 7 , 8 and 9 , the unit pixel according to this embodiment is substantially similar to the unit pixel described above, with the difference being the positional relationship between the filling layer and the light emitting element.

[0095] In this embodiment, as shown in the figure, with the transparent layer 100 as a reference, the surface 300s of the filling layer 300 away from the transparent layer 100 is higher than the highest surface 50s of the light-emitting element electrode pad. That is, the filling layer 300 is formed on a portion of the surface of the light-emitting element electrode pad and contacts the surface of the light-emitting element electrode pad. The filling layer 300 includes a plurality of openings 300a to expose the surface of the light-emitting element electrode pad. The wiring layer is formed on the filling layer and is electrically connected to the light-emitting element through the filling layer openings.

[0096] As shown in the figure, at least one or more filling layer openings 300a expose the contact area of ​​the light-emitting element electrode pad, and the wiring layer 400 partially contacts the contact area of ​​the light-emitting element electrode pad through the filling layer opening 300a. This design can not only make the wiring layer 400 electrically connected to the light-emitting element, but also prevent the problem of poor contact between the wiring layer 400 and the light-emitting element due to cracks between the electrode pad of the light-emitting element and the opening of the insulating layer 30, thereby improving the reliability of the unit pixel. If the contact area of ​​the light-emitting element electrode pad has poor electrical properties at the opening of the insulating layer, the wiring layer 400 only contacts the non-contact area of ​​the light-emitting element electrode pad, and the unit pixel 100 may be at risk of open circuit or short circuit. In a preferred embodiment, the contact area of ​​the wiring layer 400 and the light-emitting element electrode pad is at least 50% of the area of ​​the light-emitting element electrode pad contact area.

[0097] In one embodiment, as shown in FIG11 , the filling layer opening 300a includes a first opening 300a1, a second opening 300a2, a third opening 300a3, a fourth opening 300a4, a fifth opening 300a5, and a sixth opening 300a6. The first opening 300a1 exposes the first electrode pad 41 of the first light-emitting element 10a, the second opening 300a2 exposes the second electrode pad 42 of the first light-emitting element 10a, the third opening 300a3 exposes the first electrode pad 41 of the second light-emitting element 10b, the fourth opening 300a4 exposes the second electrode pad 42 of the second light-emitting element 10b, the fifth opening 300a5 exposes the first electrode pad 41 of the third light-emitting element 10c, and the sixth opening 300a6 exposes the second electrode pad 42 of the third light-emitting element 10c.

[0098] In one embodiment, the first opening portion 300a1 exposes at least a portion of the first area 41a of the first electrode pad 41 of the first light-emitting element 10a, the second opening portion 300a2 exposes at least a portion of the second area 42a of the second electrode pad 42 of the first light-emitting element 10a, the third opening portion 300a3 exposes at least a portion of the first area 41a of the first electrode pad 41 of the second light-emitting element 10b, the fourth opening portion 300a4 exposes at least a portion of the second area 42a of the second electrode pad 42 of the second light-emitting element 10b, the fifth opening portion 300a5 exposes at least a portion of the first area 41a of the first electrode pad 41 of the third light-emitting element 10c, and the sixth opening portion 300a6 exposes at least a portion of the second area 42a of the second electrode pad 42 of the third light-emitting element 10c.

[0099] In a projection direction perpendicular to the transparent layer 300, the projection of at least one or more filling layer openings 300a at least partially overlaps with an opening in the insulating layer of at least one light-emitting element. As shown in FIG11 , the projection of the first filling layer opening 300a1 partially overlaps with the projection of the first opening OP1 in the insulating layer of the first light-emitting element 10a. The projection of the second filling layer opening 300a2 partially overlaps with the projection of the second opening OP2 in the insulating layer of the first light-emitting element 10a. The projection of the third filling layer opening 300a3 partially overlaps with the projection of the first opening OP1 in the insulating layer of the first light-emitting element 10b. The projection of the fourth filling layer opening 300a4 partially overlaps with the projection of the second opening OP2 in the insulating layer of the first light-emitting element 10b. The projection of the fifth filling layer opening 300a5 partially overlaps with the projection of the first opening OP1 in the insulating layer of the third light-emitting element 10c. The projection of the sixth filling layer opening 300a6 partially overlaps with the projection of the second opening OP2 in the insulating layer of the third light-emitting element 10c.

[0100] In one embodiment, as shown in FIG11 , the projected area of ​​at least one or more filling layer openings 300a is larger than the projected area of ​​at least one first opening OP1 and / or second opening OP2 of the light-emitting element insulating layer 30. In one embodiment, referring to FIG12 , a wiring layer 400 is formed on the filling layer 300. The first wiring layer 410 is electrically connected to the first light-emitting element 10a, the second light-emitting element 10b, and the third light-emitting element 10c via the first opening 300a1, the third opening 300a3, and the fifth opening 300a5. The first wiring layer 410 includes a first portion 400a1 that contacts the first electrode pad 41 of the first light-emitting element 10a through the first opening 300a1, a second portion 400a2 that contacts the first electrode pad 41 of the second light-emitting element 10b through the second opening 300a2, and a third portion 400a3 that contacts the first electrode pad 41 of the third light-emitting element 10c through the third opening 300a3. The first portion 400a1 of the first wiring layer 410 partially contacts the first region 41a of the first electrode pad 41 of the first light-emitting element, the second portion of the first wiring layer 410 partially contacts the first region 41a of the first electrode pad 41 of the second light-emitting element, and the third portion of the first wiring layer 410 partially contacts the first region 41a of the first electrode pad 41 of the third light-emitting element. The second wiring layer 420 includes a fourth portion 400a4 that contacts the second electrode pad 42 of the first light-emitting element 10a through the second opening 300a2. The fourth portion 400a4 of the second wiring layer 420 partially contacts the second region 42a of the second electrode pad 42 of the first light-emitting element 10a. The third wiring layer 430 includes a fifth portion 400a5 that contacts the second electrode pad 42 of the second light-emitting element 10b through the fourth opening 400a4. The fifth portion 400a5 of the third wiring layer 430 partially contacts the second region 42a of the second electrode pad 42 of the second light-emitting element 10b. The fourth wiring layer 440 includes a sixth portion 400a6 that contacts the second electrode pad 42 of the third light-emitting element 10c through a sixth opening 400a6. The sixth portion 400a6 of the fourth wiring layer 440 partially contacts the second region 42a of the second electrode pad 42 of the third light-emitting element 10c. This design not only allows the wiring layer 400 to be electrically connected to the light-emitting element, but also prevents poor contact between the wiring layer 400 and the light-emitting element due to cracks between the electrode pad of the light-emitting element and the opening of the insulating layer 30, thereby improving the reliability of the unit pixel. If the contact area of ​​the light-emitting element electrode pad has poor electrical properties at the opening of the insulating layer, the wiring layer 400 will only contact the non-contact area of ​​the light-emitting element electrode pad, and the unit pixel 100 may be at risk of open circuit or short circuit.

[0101] In the projection direction perpendicular to the transparent layer, the projection of the first part 400a1 of the first wiring layer 410 coincides with the projection of the first opening 300a1 of the filling layer, the projection of the second part 400a2 of the first wiring layer 410 coincides with the projection of the third opening 300a3 of the filling layer, the projection of the third part 400a3 of the first wiring layer 410 coincides with the projection of the fifth opening 300a5 of the filling layer, the projection of the fourth part 400a4 of the second wiring layer 420 coincides with the projection of the second opening 300a2 of the filling layer, the projection of the fifth part 400a5 of the third wiring layer 430 coincides with the projection of the fourth opening 300a4 of the filling layer, and the projection of the sixth part 400a6 of the fourth wiring layer 440 coincides with the projection of the sixth opening 300a6 of the filling layer.

[0102] In one embodiment, the filling layer opening 300a is elliptical or circular.

[0103] 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 skilled in 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 one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A unit pixel, comprising: A plurality of light-emitting elements arranged at intervals, wherein at least one of the light-emitting elements includes: a semiconductor stack including a first semiconductor layer, an active layer, and a second semiconductor layer stacked in sequence; an insulating layer covering the semiconductor stack, the insulating layer including a plurality of openings, the plurality of openings including a first opening and a second opening; electrode pads including a first electrode pad and a second electrode pad, the first electrode pad being electrically connected to the first semiconductor layer through the first opening, and the second electrode pad being electrically connected to the second semiconductor layer through the second opening; A wiring layer located above the light-emitting element and electrically connected to the light-emitting element; Wherein, the electrode pads of the light-emitting element include a contact area in contact with the openings of the insulating layer, and the wiring layer is at least partially in contact with the contact area of the electrode pads of the light-emitting element.

2. The unit pixel according to claim 1, wherein It further includes a transparent layer, the plurality of light-emitting elements are arranged at intervals on the transparent layer, the contact area of the electrode pads of the light-emitting element includes a first area and a second area, the first area is the area where the first electrode pad of the light-emitting element is in contact with the first opening of the insulating layer, and the second area is the area where the second electrode pad of the light-emitting element is in contact with the second opening of the insulating layer.

3. The unit pixel according to claim 2, characterized in that, It further includes a filling layer, the filling layer is filled between adjacent light-emitting elements, taking the transparent layer as a reference, the surface of the filling layer far from the transparent layer is lower than the highest surface of the electrode pads of the light-emitting element or the surface of the filling layer far from the transparent layer is higher than the highest surface of the electrode pads of the light-emitting element.

4. The unit pixel according to claim 3, wherein The filling layer includes a plurality of openings exposing the electrode pads of the light-emitting element.

5. The unit pixel according to claim 4, wherein At least one or more of the openings of the filling layer expose the contact area of the electrode pads of the light-emitting element, and the wiring layer is in partial contact with the contact area of the electrode pads of the light-emitting element through the openings of the filling layer.

6. The unit pixel according to claim 4, characterized in that, In the projection direction perpendicular to the transparent layer, the projection area of at least one or more of the openings of the filling layer is greater than the projection area of the first opening and / or the second opening of the insulating layer of at least one light-emitting element.

7. The unit pixel according to claim 4, characterized in that, In the projection direction perpendicular to the transparent layer, the projection of at least one or more of the openings of the filling layer at least partially overlaps with the projection of the first opening and / or the second opening of the insulating layer of at least one light-emitting element.

8. The unit pixel according to claim 4, wherein, The wiring layer includes a first wiring layer, a second wiring layer, a third wiring layer, and a fourth wiring layer, 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, the second light-emitting element, and the third light-emitting element respectively include the first electrode pad and the second electrode pad, the first wiring layer is electrically connected to the first electrode pads of the first light-emitting element, the second light-emitting element, and the third light-emitting element, the second wiring layer is electrically connected to the second electrode pad of the first light-emitting element, the third wiring layer is electrically connected to the second electrode pad of the second light-emitting element, and the fourth wiring layer is electrically connected to the second electrode pad of the third light-emitting element.

9. The unit pixel according to claim 8, wherein, The filling layer opening includes a first opening, a second opening, a third opening, a fourth opening, a fifth opening, and a sixth opening. The first opening exposes at least a first region of the first electrode pad of the first light-emitting element, the second opening exposes at least a second region of the second electrode pad of the first light-emitting element, the third opening exposes at least a first region of the first electrode pad of the second light-emitting element, the fourth opening exposes at least a second region of the second electrode pad of the second light-emitting element, the fifth opening exposes at least a first region of the first electrode pad of the third light-emitting element, and the sixth opening exposes at least a second region of the second electrode pad of the third light-emitting element.

10. The unit pixel according to claim 9, characterized in that, The first wiring layer is in partial contact with the first regions of the first electrode pads of the first light-emitting element, the second light-emitting element, and the third light-emitting element through the first opening, the third opening, and the fifth opening. The second wiring layer is in partial contact with the second region of the second electrode pad of the first light-emitting element through the second opening. The third wiring layer is in partial contact with the second region of the second electrode pad of the second light-emitting element through the fourth opening. The fourth wiring layer is in partial contact with the second region of the second electrode pad of the third light-emitting element through the sixth opening.

11. The unit pixel according to claim 4, wherein, The filling layer opening is oval or circular.

12. The unit pixel according to claim 3, characterized in that, There is no filling layer on the surface of the light-emitting element electrode pad.

13. The unit pixel according to claim 12, characterized in that, In the projection direction perpendicular to the transparent layer, the projection of the contact region of at least one light-emitting element electrode pad overlaps partially with the projection of the wiring layer.

14. The unit pixel according to claim 12, wherein In the projection direction perpendicular to the transparent layer, the projection of the contact region of at least one light-emitting element electrode pad is located within the projection of the wiring layer.

15. The unit pixel according to claim 12, characterized in that, In the projection direction perpendicular to the transparent layer, the projection of at least one light-emitting element electrode pad is located within the projection of the wiring layer.

16. The unit pixel according to claim 1, characterized in that, The contact region between the wiring layer and the electrode pad of the light-emitting element is in full contact.

17. The unit pixel according to claim 8, wherein There is a minimum distance between the first wiring layer partially formed on the first light-emitting element and the second wiring layer partially formed on the first light-emitting element, or between the first wiring layer partially formed on the second light-emitting element and the third wiring layer partially formed on the second light-emitting element, or between the first wiring layer partially formed on the third light-emitting element and the fourth wiring layer partially formed on the third light-emitting element. The minimum distance is between 1 and 50 μm.

18. The unit pixel according to claim 1, wherein, The minimum width of the wiring layer is not less than 1 to 50 μm.

19. The unit pixel according to claim 1, characterized in that, The contact area of the contact region between the wiring layer and the light-emitting element electrode pad accounts for at least more than 50% of the area of the contact region of the light-emitting element electrode pad.

20. A display device, characterized in that, It includes a panel substrate and a plurality of pixel modules fixed to the panel substrate. The pixel module includes the unit pixel according to any one of claims 1 to 19.

Images