Micro-luminescent structure, preparation method and luminescent device

Abstract

The present application provides a micro-light-emitting structure, a preparation method and a light-emitting device, which relate to the field of light-emitting technology. The micro-light-emitting structure includes a light-emitting chip and a driving chip. The light-emitting chip includes a light-emitting unit and a cover plate. The light-emitting unit is provided with a plurality of light-emitting units. The cover plate is attached to the light-emitting side of the light-emitting unit. The side where the cover plate is attached to the light-emitting unit is provided with a plurality of recessed parts. The recessed parts are arranged corresponding to the light-emitting units. The driving chip is connected to a non-light-emitting side of the light-emitting chip. The present application can improve the light utilization rate of the micro-light-emitting structure, thereby improving the light-emitting efficiency and reducing the light crosstalk phenomenon.

Description

Technical Field

[0001] The present application relates to the field of light-emitting technology, and in particular to a micro light-emitting structure, a preparation method and a light-emitting device. Background Art

[0002] Micro-LED (Micro-Light Emitting Diode) display technology refers to a display technology that uses self-luminous micron-sized LEDs as light-emitting pixel units and assembles them on a driving panel to form a high-density LED array.

[0003] In the related art, the light-emitting structure has problems of low light-emitting efficiency and light crosstalk in terms of color pattern display. Summary of the invention

[0004] The present application provides a micro-light-emitting structure, a preparation method and a light-emitting device.

[0005] The technical solutions adopted in this application are as follows:

[0006] In a first aspect, an embodiment of the present application provides a micro-light emitting structure, comprising:

[0007] A light-emitting chip, the light-emitting chip comprising a light-emitting unit and a cover plate, the light-emitting unit is provided in plurality, the cover plate is attached to the light-emitting side of the light-emitting unit, a side of the cover plate attached to the light-emitting unit is provided with a plurality of recessed parts, and the recessed parts are arranged corresponding to the light-emitting unit;

[0008] A driving chip is connected to a non-light-emitting side of the light-emitting chip.

[0009] In one of the embodiments of the first aspect, a dimming layer is disposed in at least part of the recessed portion, the dimming layer constitutes a plurality of groups of dimming units, each group of the dimming units is composed of at least two of the dimming layers, and each group of the dimming units is used to synthesize white light based on the light emitted by the corresponding light-emitting unit.

[0010] In one embodiment of the first aspect, each group of the dimming units includes three dimming layers, and the three dimming layers respectively convert the light emitted by the light-emitting unit into red primary color light, green primary color light and blue primary color light.

[0011] In one embodiment of the first aspect, the cover plate includes a filter, and the recessed portion is opened on a side of the filter close to the light-emitting unit.

[0012] In one of the embodiments of the first aspect, the cover plate includes a substrate and a light-gathering layer which are stacked, and the light-gathering layer is provided with the recessed portion on a side facing away from the substrate.

[0013] In one embodiment of the first aspect, the micro light-emitting structure further includes an adhesive layer, and two opposite sides of the adhesive layer are respectively bonded to the light-emitting unit and the cover plate;

[0014] The light-emitting unit comprises a first semiconductor layer, a second semiconductor layer, a light-emitting layer, a third semiconductor layer, a current spreading layer, a metal electrode, a passivation layer and a bonding layer which are stacked;

[0015] The first semiconductor layer is connected to the bonding layer, the second semiconductor layer is arranged on a side of the first semiconductor layer away from the bonding layer, a plurality of spaced bosses are arranged on a side of the second semiconductor layer away from the first semiconductor layer, the light emitting layer, the third semiconductor layer, the current spreading layer and the metal electrode are sequentially stacked on the end faces of the bosses of the second semiconductor layer, the passivation layer is attached to the surfaces of the second semiconductor layer, the light emitting layer, the third semiconductor layer, the current spreading layer and the metal electrode, and the bonding layer is penetrated through the passivation layer and connected to the metal electrode;

[0016] The cover plate includes a filter, and the recessed portion is opened on a side of the filter close to the light-emitting unit;

[0017] or,

[0018] The cover plate comprises a substrate and a light-gathering layer which are stacked, and the light-gathering layer is provided with the recessed portion on a side away from the substrate.

[0019] In a second aspect, the present application also provides a method for preparing a micro-light-emitting structure, including:

[0020] Acquire a light-emitting unit bonded to a driver chip;

[0021] Obtaining a cover plate having a plurality of recessed portions;

[0022] The recessed portion of the cover plate is aligned with the light emitting unit and bonded thereto.

[0023] In one embodiment of the second aspect, obtaining a cover plate having a plurality of recessed portions comprises:

[0024] Selecting a filter, and performing patterning on one side of the filter to form the recessed portion;

[0025] or,

[0026] A substrate is selected, a resin material layer is coated on the substrate to form a light-gathering layer, and a mold with arc-shaped protrusions is used to perform nano-imprinting on the light-gathering layer to form the concave portion.

[0027] In one embodiment of the second aspect, after obtaining the cover plate having a plurality of recessed portions, the method further includes:

[0028] A dimming layer is arranged in at least part of the recessed portion, the dimming layer constitutes a plurality of groups of dimming units, each group of the dimming units is composed of at least two dimming layers, and each group of the dimming units is used to synthesize white light based on the light emitted by the corresponding light-emitting unit.

[0029] In a third aspect, an embodiment of the present application further provides a light-emitting device, comprising the micro-light-emitting structure described in any of the above embodiments.

[0030] The present application proposes a micro-light-emitting structure, a preparation method and a light-emitting device. Compared with the related art, the present application forms a micro-lens by opening a recessed portion on the cover plate, and the recessed portion and the critical surface of the cover plate are formed into a micro-lens, and the side of the cover plate provided with a dimming layer covers the light-emitting side of the light-emitting unit. During operation, the light emitted by the light-emitting unit is directed toward the micro-lens, and under the action of the micro-lens, the divergent light is collimated, which has a good focusing effect, improves the light utilization rate of the micro-light-emitting structure, and can further improve the luminous efficiency and reduce the light crosstalk phenomenon. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. 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 related drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 A schematic diagram of the structure of a micro-light-emitting structure in some embodiments of the present application is shown;

[0033] Figure 2 Shows schematic structural diagrams of micro-light-emitting structures in other embodiments of the present application;

[0034] Figure 3 A schematic diagram of the structure of the epitaxial layer in some embodiments of the present application is shown;

[0035] Figure 4 A schematic diagram showing the structure of a pixel structure in some embodiments of the present application is shown;

[0036] Figure 5 A schematic diagram of the structure of the current spreading layer in some embodiments of the present application is shown;

[0037] Figure 6 Shows a schematic diagram of the structure of metal electrodes in some embodiments of the present application;

[0038] Figure 7 The schematic diagram of the structure of the passivation layer in some embodiments of the present application is shown;

[0039] Figure 8 A schematic diagram of the structure of the bonding layer in some embodiments of the present application is shown;

[0040] Fig. 9 A schematic diagram of the structure of a light-emitting unit in some embodiments of the present application is shown;

[0041] Fig.10 A schematic diagram of the structure after the light-emitting unit and the driver chip are bonded in some embodiments of the present application is shown;

[0042] Fig.11 The structure schematic diagram of the filter in some embodiments of the present application is shown;

[0043] Fig.12 A schematic diagram of the structure of the recessed portion in some embodiments of the present application is shown;

[0044] Fig.13 A schematic diagram of the structure of the dimming layer in some embodiments of the present application is shown;

[0045] Fig.14 Shows a schematic structural diagram of a substrate in some other embodiments of the present application;

[0046] Fig.15 A schematic structural diagram of a mold imprinting process in some other embodiments of the present application is shown;

[0047] Fig.16 It shows a schematic diagram of the structure of the recessed portion in some other embodiments of the present application;

[0048] Fig.17 Shows a schematic structural diagram of a dimming layer in other embodiments of the present application;

[0049] Fig.18 A schematic diagram showing the structure of the dimming layer curing process in other embodiments of the present application is shown;

[0050] Fig.19 It shows a schematic diagram of the structure of the recessed portion in some other embodiments of the present application;

[0051] Fig. 20 It shows a schematic diagram of the structure of the orthographic projection pattern of the concave portion in some embodiments of the present application;

[0052] Fig.21 It shows a schematic structural diagram of the orthographic projection pattern of the concave portion in some other embodiments of the present application;

[0053] Fig. 22 A flow chart showing a method for preparing a micro-light-emitting structure in some embodiments of the present application is shown;

[0054] Fig.23 The process of preparing the recessed portion in some embodiments of the present application is shown Figure 1 ;

[0055] Fig.24 The process of preparing the recessed portion in some embodiments of the present application is shown Figure 2 .

[0056] Description of main symbols:

[0057] 100-micro light-emitting structure; 110-light-emitting chip; 111-light-emitting unit; 1111-first semiconductor layer; 1112-second semiconductor layer; 1113-light-emitting layer; 1114-third semiconductor layer; 1115-current spreading layer; 1116-metal electrode; 1117-passivation layer; 1118-bonding layer; 1119-substrate; 112-cover plate; 1121-filter; 1122-dimming layer; 1123-substrate; 1124-light-gathering layer; 1125-recessed portion; 113-adhesive layer; 120-driving chip;

[0058] 200-UV lamp; 300-mold. DETAILED DESCRIPTION

[0059] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0060] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0061] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0062] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0063] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0064] The micro-light-emitting structure 100 provided in the present solution can be applied not only to the projection part of electronic devices such as optical projection and HUD (Head Up Display), but also to the display part of electronic devices. For example, the electronic devices may include: smart phones, smart watches, laptops, tablet computers, driving recorders, navigators, head-mounted devices, and any other devices with display screens. It can also be applied to the lighting part of electronic devices. For example, the electronic devices may include: vehicles, street lamps, and any other devices with lighting components.

[0065] The embodiment of the present application provides a micro-light emitting structure 100, which can effectively collimate and converge light, improve the light utilization rate of the micro-light emitting structure 100, reduce light crosstalk and color deviation of the display screen, etc. It can be used in the fields of augmented reality (AR), virtual reality (VR), MR, projection, etc.

[0066] like Figure 1 and Figure 2 As shown, the micro light-emitting structure 100 includes a light-emitting chip 110 and a driving chip 120. The light-emitting chip 110 includes a light-emitting unit 111 and a cover plate 112. There are multiple light-emitting units 111, and the multiple light-emitting units 111 can be arranged in an array. The cover plate 112 is attached to the light-emitting side of the light-emitting unit 111. A plurality of recesses 1125 are provided on one side of the cover plate 112 where the light-emitting unit 111 is attached. The recesses 1125 are arranged corresponding to the light-emitting units 111.

[0067] In the present application, the light emitting chip 110 may be a micro-LED chip such as a Micro-LED chip or a Mini-LED chip. In the present embodiment, the micro light emitting structure 100 may be a Micro-LED chip.

[0068] A plurality of light-emitting units 111 are arranged in an array to form a light-emitting matrix, and each light-emitting unit 111 can emit a monochromatic light, which is refracted from the light-emitting side after passing through the recessed portion 1125. The recessed portion 1125 is arranged in a one-to-one correspondence with the light-emitting unit 111, that is, a recessed portion 1125 is arranged on the light-emitting side of each light-emitting unit 111. Through the arrangement of the recessed portion 1125, a microlens is formed at the zero interface between the recessed portion 1125 and the substrate 1123, and the light is refracted at the mirror surface of the microlens, which collimates and focuses the light emitted by the light-emitting unit 111, improves the utilization rate of the light, and can thereby reduce the light emission angle of the light, and reduce the phenomenon of crosstalk between the light emitted by adjacent light-emitting units 111.

[0069] The driver chip 120 is connected to a non-light-emitting side of the light-emitting chip 110. During the operation of the light-emitting device, the driver chip 120 can control the light-emitting operation of the light-emitting chip 110. The driver chip 120 can be a CMOS (Complementary Metal Oxide Semiconductor) driver board or a TFT (Thin Film Transistor) driver board. In this embodiment, the driver chip 120 uses a CMOS driver board.

[0070] In some embodiments, a dimming layer 1122 is disposed in at least part of the recessed portion 1125. Here, at least part of the recessed portion 1125 may refer to part or all of the recessed portions 1125 on the side where the cover plate 112 and the light-emitting unit 111 are attached, that is, one or more recessed portions 1125 in the aforementioned multiple recessed portions 1125 in the cover plate 112.

[0071] The dimming layer 1122 may be filled with a light color conversion material to convert the monochromatic light emitted by the light emitting unit 111 into a corresponding material color, so that the micro-light emitting structure 100 can form a color display. In the case of providing two or more color adjustment units corresponding to different colors, the more types are provided, the wider the color gamut of the micro-light emitting structure 100.

[0072] The dimming layer 1122 can be set according to actual needs. When the light emitted by the light-emitting unit 111 needs to be converted in color, the dimming layer 1122 can be set in the corresponding recess 1125. During the operation of the micro-light-emitting structure 100, when the light emitted by the light-emitting unit 111 does not need to be converted in color, the dimming layer 1122 is not set in the corresponding recess 1125. Figure 1 As shown, Figure 1 The dimming layer 1122 may not be provided in the first recessed portion 1125 on the left side in the middle, so as to retain the original color of the light of the corresponding light emitting unit 111. At this time, the recessed portion 1125 only plays the role of focusing light, reducing the light crosstalk problem of the light emitted by the light emitting unit 111 to the adjacent light emitting unit 111. The other recessed portions 1125 are filled with dimming layers 1122, which can convert the original color of the light of the corresponding light emitting unit 111 into the corresponding color of the dimming layer 1122. Through the arrangement of the recessed portions 1125 and the dimming layer 1122, the light emitted by the light emitting unit 111 is focused and converted into the corresponding light color, forming a full-color display.

[0073] In some embodiments, the dimming layer 1122 constitutes a plurality of groups of dimming units, each group of dimming units is composed of at least two dimming layers 1122, and each group of dimming units is used to synthesize white light based on the light emitted by the corresponding light emitting unit 111. Each dimming layer 1122 included in each group of dimming units can convert the light emitted by the light emitting unit 111 into corresponding primary color light, and white light can be synthesized based on these primary color lights. Here, the primary colors are not limited to the three primary colors of red, green and blue, and can also be other combinations such as yellow and blue.

[0074] The plurality of dimming layers 1122 are arranged in an array in the horizontal direction, and the number of dimming layers 1122 required to form a group of dimming units is two or more. Specifically, each dimming layer 1122 can convert the light emitted by the light-emitting unit 111 into a monochromatic light, and the plurality of dimming layers 1122 in each group of dimming units can be mixed to form white light, and each group of dimming units can be any primary color combination of synthesized white light, such as a combination of blue light and yellow light obtained by exciting yellow phosphor with blue light.

[0075] In one embodiment, each group of dimming units includes three dimming layers 1122, and the three dimming layers 1122 convert the light emitted by the light emitting unit 111 into red primary color light, green primary color light and blue primary color light respectively. In implementation, when the light emitted by the light emitting unit 111 is primary color light, the dimming layer 1122 may not be filled with corresponding dimming materials. For example, when the light emitted by the light emitting unit 111 is blue primary color light, the corresponding blue dimming material may not be filled at this time. In this way, it is not necessary to perform color conversion on the light emitted by the light emitting unit 111, but the blue light emitted by the light emitting unit 111 and the primary color light after color conversion are synthesized to obtain white light.

[0076] During implementation, the conversion colors of the three dimming layers 1122 in each group of dimming units may be arranged in sequence, for example, in the order of “red—green—blue”.

[0077] In one embodiment, the light emitted by the light emitting unit 111 is blue light, and the two dimming layers 1122 in each dimming unit group are filled with red quantum dot materials and green quantum dot materials, respectively, to convert the original blue light into red light and green light. The dimming layer 1122 of the blue unit is not filled with quantum dot materials, and can be adapted to be filled with other materials, such as polyester materials with high refractive index. In other embodiments, blue quantum dot materials can be filled in the blue unit to improve the color purity of the blue light used to synthesize white light.

[0078] In another embodiment, the emitted light of the light-emitting unit 111 is purple light, and the three dimming layers 1122 in each group of dimming units are respectively filled with red quantum dot material, green quantum dot material, and blue quantum dot material to convert the original purple light into red light, green light, and blue light.

[0079] The purple light may be purple visible light or ultraviolet light.

[0080] like Fig.13 As shown, in some embodiments, the cover plate 112 includes a filter 1121 , which may be a QDCF (quantum dot color filter), and the recess 1125 is opened on a side of the filter 1121 close to the light emitting unit 111 .

[0081] QDCF can accurately select a small range of wavelengths of light waves to be passed through, and reflect other unnecessary wavelengths. The filter 1121 can be installed on the light-emitting side of the light-emitting unit 111, so that the human eye can receive saturated primary color light.

[0082] like Fig.17 As shown, in some other embodiments, the cover plate 112 includes a substrate 1123 and a light-gathering layer 1124 that are stacked, and a recessed portion 1125 is formed on a side of the light-gathering layer 1124 that is away from the substrate 1123 .

[0083] The substrate 1123 may include materials such as glass, Si (silicon), SiC (silicon carbide), GaAs (gallium arsenide), AlN (aluminum nitride), ZnO (zinc oxide), etc. In this embodiment, the substrate 1123 may be a glass substrate 1123 .

[0084] The focusing layer 1124 can be made of a transparent resin material, and its refractive index should be smaller than that of the adhesive layer 113, so that the light emitted by the light-emitting unit 111 is refracted at the critical surface between the recess 1125 and the substrate 1123, and the light moves closer to the axis of the recess 1125, thereby improving the collimation and aggregation effects of the light.

[0085] like Fig.12 and Fig.19 As shown, in some embodiments, the structure of the recessed portion 1125 includes at least one of the following: an arc-shaped recess and a polygonal recess.

[0086] The polygonal depression may be an open figure composed of multiple edges connected in sequence at a certain angle, and the number of edges of the open figure may be two, three, four, five, six, etc. Among them, the connection angle of two adjacent edges may be 10°, 15°, 20°, 30°, 40°, 60°, 90°, 120°, 150°, etc.

[0087] like Fig.19 As shown, in one embodiment, the recessed portion 1125 may be an open figure consisting of four sides.

[0088] In the present application, the structure of the recessed portion 1125 may be an arc-shaped structure, which has better effects on light collimation and focusing.

[0089] In another embodiment, the arc-shaped depression may be an aspherical curvature structure. For lenses with aspherical curvature, the radius of curvature gradually increases from the center to the periphery of the lens, and the lens surface gradually becomes flat, which has a better effect on light gathering and collimation, and the imaging is more realistic and natural compared to spherical lenses.

[0090] In other embodiments, the recessed portion 1125 is an axisymmetric structure.

[0091] Through the axial symmetry of the recessed portion 1125, the emitted light in the middle is dispersed outward in a symmetrical manner, and the scattered light on the peripheral side can be refracted in a mirrored manner on the mirror surface of the recessed portion 1125, and finally maintain the same emission direction. At the same time, it can also meet the standard uniformity and process aesthetics of industrial production, and facilitate industrial production.

[0092] like Fig. 20 and Fig.21 As shown, in some embodiments, the orthographic projection shape of the recessed portion 1125 on the light emitting unit 111 includes at least one of the following: a circle, a regular polygon.

[0093] The light-emitting side of the light-emitting unit 111 is a planar structure, the substrate 1123 is parallel to and covers the light-emitting unit 111, and the light-emitting side of the light-emitting unit 111 is used as a projection plane, and the recessed portion 1125 is projected by parallel light in a direction perpendicular to the projection plane to obtain an orthographic projection pattern of the recessed portion 1125. That is, the recessed portion 1125 is close to the end surface structure of the light-emitting unit 111 side.

[0094] The orthographic projection shape of the recessed portion 1125 may be a regular triangle, a regular quadrilateral, a regular pentagon, a regular hexagon, or the like.

[0095] like Fig.21 As shown, in one embodiment, the orthographic projection shape of the recessed portion 1125 may be a regular quadrilateral.

[0096] In some embodiments, the micro-light emitting structure 100 further includes an adhesive layer 113, and opposite sides of the adhesive layer 113 are respectively bonded to the light emitting unit 111 and the cover plate 112. When the dimming layer 1122 is not filled in the recess 1125, the adhesive layer 113 can be filled in the recess 1125. In this embodiment, the adhesive layer 113 can be an ultraviolet curing UV glue, and in some embodiments, other light-transmitting colloids can also be used.

[0097] The light-emitting unit 111 includes a first semiconductor layer 1111 , a second semiconductor layer 1112 , a light-emitting layer 1113 , a third semiconductor layer 1114 , a current spreading layer 1115 , a metal electrode 1116 , a passivation layer 1117 and a bonding layer 1118 , and the cover plate 112 is attached to the first semiconductor layer 1111 .

[0098] The first semiconductor layer 1111 is connected to the bonding layer 113, the second semiconductor layer 1112 is arranged on the side of the first semiconductor layer 1111 away from the bonding layer 113, and a plurality of spaced bosses are arranged on the side of the second semiconductor layer 1112 away from the first semiconductor layer 1111. The light-emitting layer 1113, the third semiconductor layer 1114, the current spreading layer 1115 and the metal electrode 1116 are stacked in sequence on the end faces of the bosses of the second semiconductor layer 1112. The passivation layer 1117 is attached to the surfaces of the second semiconductor layer 1112, the light-emitting layer 1113, the third semiconductor layer 1114, the current spreading layer 1115 and the metal electrode 1116, and the bonding layer 1118 penetrates the passivation layer 1117 and is connected to the metal electrode 1116.

[0099] The first semiconductor layer 1111 may be a U-GaN (U-type gallium nitride) layer, the second semiconductor layer 1112 may be an N-GaN (N-type gallium nitride) layer, and the third semiconductor layer 1114 may be a P-GaN (P-type gallium nitride) layer. The second semiconductor layer 1112 may be used as a cathode connection layer of the micro-light emitting structure 100, and the third semiconductor layer 1114 may be used as an anode connection layer of the micro-light emitting structure 100.

[0100] In other embodiments, the light-emitting unit 111 may only include a second semiconductor layer 1112 , a light-emitting layer 1113 , a third semiconductor layer 1114 , a current spreading layer 1115 , a metal electrode 1116 , a passivation layer 1117 and a bonding layer 1118 , and the cover plate 112 is attached to the second semiconductor layer 1112 .

[0101] The light emitting layer 1113 may be a MQW (Multiple Quantum Well) light emitting layer 1113 .

[0102] The current spreading layer 1115 may be made of at least one of materials such as ITO (Indium tin oxide), FTO (Fluorine tin oxide), and AZO (Aluminum zinc oxide).

[0103] In this embodiment, the current spreading layer 1115 may be made of ITO material.

[0104] The metal electrode 1116 may be formed by sequentially depositing Ti / Al / Ti / Au (titanium / aluminum / titanium / gold) metal layers using an ion beam evaporation method.

[0105] In some other embodiments, the metal electrode 1116 may also be made of Ni / Fe / Pt / Pd (nickel / iron / platinum / palladium) metal, or other conductive materials.

[0106] A through hole is provided at the contact portion between the passivation layer 1117 and the metal electrode 1116 to expose a portion of the metal electrode 1116. The passivation layer 1117 can be made of materials such as polyvinyl chloride, epoxy resin, acrylic resin, polyamide resin, polyvinyl alcohol, natural rubber, polystyrene or SiO2 (silicon dioxide).

[0107] In this embodiment, the passivation layer 1117 is formed by depositing SiO2.

[0108] The bonding layer 1118 may be made of metal materials such as gold, titanium, nickel, aluminum, copper, indium, tin, or silver-tin alloy.

[0109] In this embodiment, the bonding layer 1118 is formed by depositing metal indium.

[0110] The embodiments of the present application further provide a method for preparing a micro-light-emitting structure 100 , which can be used to prepare the micro-light-emitting structure 100 in any of the above embodiments.

[0111] like Fig. 22 As shown, the preparation method of the micro-light emitting structure 100 includes:

[0112] S10 , obtaining the light emitting unit 111 bonded to the driving chip 120 .

[0113] Combined Figure 3 As shown, a substrate 1119 is selected as a growth carrier of the epitaxial layer, and a first semiconductor layer 1111, a second semiconductor layer 1112, a light-emitting layer 1113, and a third semiconductor layer 1114 are sequentially deposited on the substrate 1119. The first semiconductor layer 1111, the second semiconductor layer 1112, the light-emitting layer 1113, and the third semiconductor layer 1114 can be grown by different or the same epitaxial growth methods, respectively. For example, they can be grown by one of the epitaxial growth methods such as a vapor phase epitaxial growth method, a liquid phase epitaxial growth method, or a molecular beam epitaxial growth method.

[0114] Combined Figure 4 As shown, etching is performed from one side of the third semiconductor layer 1114 to form a plurality of bosses, but a portion of the thickness of the second semiconductor layer 1112 is still retained, that is, a portion of the second semiconductor layer 1112 is exposed within the range of the boss structure.

[0115] Combined Figure 5 As shown, an ITO material can be deposited on the surface of the side of the boss away from the substrate 1119 by a magnetron sputtering method to obtain a current spreading layer 1115.

[0116] Combined Figure 6 As shown, Ti / Al / Ti / Au metal layers can be deposited in sequence on the surface of the current spreading layer 1115 away from the third semiconductor layer 1114 by ion beam evaporation to form a metal electrode 1116 .

[0117] Combined Figure 7 As shown, a passivation layer 1117 can be deposited on the side of the metal electrode 1116 and the second semiconductor layer 1112 away from the substrate 1119 by a PECVD (Plasma Enhanced Chemical Vapor Deposition) method, and the passivation layer 1117 material is sequentially attached to the second semiconductor layer 1112, the light-emitting layer 1113, the third semiconductor layer 1114, the current spreading layer 1115 and the side of the metal electrode 1116. After the passivation layer 1117 is formed, a through hole is opened on the passivation layer 1117 by a photolithography process, and the through hole is opposite to the metal electrode 1116. It can be understood that the through hole can connect the external environment and the metal electrode 1116. Accordingly, at least a portion of the surface of the metal electrode 1116 away from the substrate 1119 can be exposed through the through hole on the passivation layer 1117.

[0118] Combined Figure 8As shown, a bonding layer 1118 can be deposited on the metal electrode 1116 at the position corresponding to the through hole by the PECVD method, and the bonding layer 1118 is made to protrude from the surface of one side of the passivation layer 1117 away from the substrate 1119 to facilitate welding of the bonding layer 1118 and the driving chip 120.

[0119] Combined Fig. 9 As shown, LLO (Laser Lift-off) can be used to remove the substrate 1119 to expose the first semiconductor layer 1111. Specifically, laser is irradiated on one side of the substrate 1119, and the energy of the laser causes the first semiconductor layer 1111 to be thermally decomposed on the side close to the substrate 1119, thereby separating the substrate 1119 from the first semiconductor layer 1111, that is, stripping the substrate 1119.

[0120] Combined Fig.10 As shown, a ball key method can be used to electrically connect the bonding layer 1118 and the driver chip 120 to obtain the light-emitting chip 110 provided in the present application. The bonding process of the driver chip 120 and the light-emitting unit 111 can occur after the substrate 1119 is peeled off, or before the substrate 1119 is peeled off, the driver chip 120 and the light-emitting unit 111 are bonded first, and then the substrate 1119 is peeled off. The order of the two processes can be interchanged as long as the effect of the present application can be achieved.

[0121] S20, obtaining a cover plate 112 having a plurality of recessed portions 1125.

[0122] like Fig.23 As shown, in some embodiments, step S20 includes:

[0123] S21, select a filter 1121.

[0124] Combined Fig.11 As shown, a filter 1121 may be obtained first, and the filter 1121 may be obtained by purchase or preparation. Of course, in other embodiments, the filter 1121 may also be made of a light-transmitting flat material. In this embodiment, the use of the filter 1121 may make the primary color light that can be received by the human eye more saturated, thereby improving the display effect.

[0125] S22 , performing image processing on one side of the filter 1121 to form a recessed portion 1125 .

[0126] Combined Fig.12As shown, the image processing can produce a preset pattern on the corresponding substrate by using etching, photolithography and other processes. In this embodiment, the image processing uses an etching process, and a mask can be deposited on one side of the filter 1121, and then a dry etching or wet etching process is used to etch the mask side of the filter 1121 to generate a recessed portion 1125 of a preset shape.

[0127] like Fig.24 As shown, in some other embodiments, step S20 includes:

[0128] S23, selecting a substrate 1123.

[0129] The substrate 1123 can be obtained by purchasing or preparing. The substrate 1123 can be one of glass, Si (silicon), SiC (silicon carbide), GaAs (gallium arsenide), AlN (aluminum nitride), ZnO (zinc oxide), etc. In this embodiment, the substrate 1123 can be a glass substrate 1123.

[0130] S24 , coating a resin material layer on the substrate 1123 to form a light-collecting layer 1124 .

[0131] Combined Fig.14 As shown, after selecting the substrate 1123, a transparent resin material is coated on one side of the substrate 1123, and the refractive index of the resin material layer should be smaller than that of the adhesive layer 113 to ensure that after the recess 1125 is formed, the critical surface of the recess 1125 can collimate the light emitted by the light-emitting unit 111.

[0132] S25 , using the mold 300 to perform nano-imprinting on the light-condensing layer 1124 to form the recessed portion 1125 .

[0133] Combined Fig.15 and 16 As shown, a suitable mold 300 is selected, and the shape of the mold 300 can be set according to the preset shape of the recessed portion 1125. The mold 300 is placed vertically above the resin material layer, and printed using nanoimprint technology. After the printing is completed, the mold is demolded to separate the mold 300 from the resin material layer to form the recessed portion 1125.

[0134] In this embodiment, one side of the mold 300 is a planar structure, and the opposite side has multiple arc-shaped protrusions at equal intervals, and the spacing between two adjacent protrusions is the same as the spacing between two adjacent light-emitting units 111. After nano-pressing, the resin material layer forms an arc-shaped recessed portion 1125 that matches the arc-shaped protrusions to aggregate and collimate the light emitted by the light-emitting unit 111.

[0135] S30 , generating a light-adjusting layer 1122 in the recessed portion 1125 .

[0136] Combined Fig.17 As shown, the colored quantum dot material is filled in the recessed portion 1125 where light conversion is required, and the quantum dot material and the end surface of the recessed portion 1125 are smoothed.

[0137] Combined Fig.13 and 18 As shown, after the colored quantum dot material is injected into the recessed portion 1125 , an ultraviolet lamp 200 may be disposed vertically above the quantum dot material to perform ultraviolet curing, thereby finally forming the dimming layer 1122 .

[0138] S40, aligning and bonding the recessed portion 1125 of the cover plate 112 and the light emitting unit 111.

[0139] The glue layer can be applied simultaneously on the side of the light-emitting unit 111 and the cover plate 112 where the dimming layer 1122 is provided, or the glue layer can be applied only on one of the surfaces of the two, and then the cover plate 112 is covered on the light-emitting unit 111, and part of the glue layer fills the recessed portion 1125 where the dimming layer 1122 is not provided. After the glue layer is hardened, an adhesive layer 113 is formed to bond the cover plate 112 to the light-emitting unit 111.

[0140] The micro-luminous structure proposed in the present application is particularly suitable for the following electronic devices: projection equipment for long-distance display, such as optical projection, etc.; application equipment that has requirements for display brightness, such as vehicle-mounted products such as window displays and HUDs that are usually used outdoors, sights and telescopes in the military industry, and head-mounted devices such as AR glasses, ski goggles, swimming goggles, etc.

[0141] An embodiment of the present application further provides a light-emitting device, comprising the micro-light-emitting structure 100 in any of the above embodiments.

[0142] This embodiment has the micro-light emitting structure 100 in any of the above embodiments, and therefore has all the beneficial effects of the micro-light emitting structure 100 in any of the above embodiments.

[0143] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0144] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A micro-light emitting structure, characterized in that: include: A light-emitting chip, the light-emitting chip comprising a light-emitting unit and a cover plate, the light-emitting unit is provided with a plurality of light-emitting units, the cover plate is attached to the light-emitting side of the light-emitting unit, a side of the cover plate attached to the light-emitting unit is provided with a plurality of recessed parts, the recessed parts are arranged corresponding to the light-emitting units, so that the critical surface of the recessed parts and the cover plate forms a microlens; A driving chip connected to a non-light-emitting side of the light-emitting chip; A dimming layer is arranged in the entire recessed portion, the dimming layer constitutes a plurality of groups of dimming units, each group of the dimming units is composed of at least two dimming layers, and each group of the dimming units is used to synthesize white light based on the light emitted by the corresponding light emitting unit; The cover plate is a filter, and the recessed portion is opened on a side of the filter close to the light-emitting unit; the dimming layer is filled in the recessed portion and has a first surface close to the light-emitting unit, the first surface is flush with the surface of the filter, and the first surface is arranged parallel to the light-emitting side of the light-emitting unit; The micro-light emitting structure further comprises an adhesive layer, and two opposite sides of the adhesive layer are respectively bonded to the light emitting unit and the recessed portion of the cover plate, and are filled in the recessed portion not filled with the dimming layer.

2. The micro-light emitting structure according to claim 1, characterized in that: Each group of the dimming units includes three dimming layers, and the three dimming layers convert the light emitted by the light-emitting unit into red primary color light, green primary color light and blue primary color light respectively.

3. The micro-light emitting structure according to claim 1, characterized in that: The light-emitting unit comprises a first semiconductor layer, a second semiconductor layer, a light-emitting layer, a third semiconductor layer, a current spreading layer, a metal electrode, a passivation layer and a bonding layer which are stacked; The second semiconductor layer is arranged on a side of the first semiconductor layer away from the bonding layer, a plurality of spaced bosses are arranged on the side of the second semiconductor layer away from the first semiconductor layer, the light emitting layer, the third semiconductor layer, the current spreading layer and the metal electrode are sequentially stacked on the end faces of the bosses of the second semiconductor layer, the passivation layer is attached to the surfaces of the second semiconductor layer, the light emitting layer, the third semiconductor layer, the current spreading layer and the metal electrode, and the bonding layer is penetrated through the passivation layer and connected to the metal electrode; The cover plate includes a filter, and the recessed portion is opened on a side of the filter close to the light-emitting unit.

4. A method for preparing a micro-luminescent structure, characterized in that: A method for manufacturing a micro-light emitting structure according to any one of claims 1 to 3, comprising: Acquire a light-emitting unit bonded to a driver chip; Obtaining a cover plate having a plurality of recessed portions; Aligning and bonding the recessed portion of the cover plate to the light-emitting unit; Wherein, the step of obtaining a cover plate with a plurality of recessed portions comprises: selecting a filter and performing a patterning process on one side of the filter to form the recessed portions; After obtaining the cover plate with multiple recessed portions, the method further includes: setting a dimming layer in at least part of the recessed portions, the dimming layer constituting a plurality of groups of dimming units, each group of the dimming units consisting of at least two of the dimming layers, and each group of the dimming units being used to synthesize white light based on the light emitted by the corresponding light-emitting unit.

5. A light emitting device, characterized in that: The micro-light emitting structure comprises the micro-light emitting structure as claimed in any one of claims 1 to 3.

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