Micro light emitting diode display and method of manufacturing the same

Abstract

The application relates to the micro display technical field, and discloses a micro light emitting diode display and a preparation method thereof. The micro light emitting diode display comprises a substrate, a bonding layer and a plurality of LED units. The bonding layer is arranged on the substrate, and the bonding layer comprises a plurality of connecting units, a plurality of insulating units and a reflection area. The plurality of connecting units are arranged in an array on the substrate. The outer side of each connecting unit is surrounded by an insulating unit, and the reflection area is located between adjacent insulating units. The plurality of LED units are arranged one by one on the plurality of connecting units. The substrate is electrically connected with the corresponding LED unit through the connecting unit, so that each LED unit can be individually driven. In the application, electrical and optical isolation is realized through the insulating units and the reflection area, optical crosstalk is reduced, and brightness is improved.

Description

Technical Field

[0001] This application belongs to the field of micro-display technology, specifically relating to a micro light-emitting diode display and its fabrication method. Background Technology

[0002] Micro LEDs possess advantages such as high resolution, high contrast, high luminous efficiency, and long lifespan, making them ideal devices for near-eye head-mounted displays and large-area self-emissive displays. Micro LEDs can also be used in visible light communication, offering advantages such as high modulation bandwidth, high communication speed, and the potential to achieve bidirectional communication and intelligent displays.

[0003] While Micro LEDs exhibit excellent performance in displays and visible light communication, the reduction in size leads to a decrease in the proportion of the light-emitting area for the same chip size, resulting in lower device brightness. Furthermore, the reduction in pixel pitch to a few micrometers exacerbates optical crosstalk. Summary of the Invention

[0004] This application aims to address at least one of the technical problems existing in the prior art or related technologies.

[0005] Therefore, the first aspect of this application provides a miniature light-emitting diode display.

[0006] A second aspect of this application provides a method for fabricating a miniature light-emitting diode display.

[0007] In view of this, according to a first aspect of the embodiments of this application, a micro light-emitting diode display is provided, comprising: a substrate; a bonding layer disposed on the substrate, including a plurality of connection units, a plurality of insulating units, and a reflective region, wherein the plurality of connection units are arranged in an array on the substrate, each connection unit is surrounded by an insulating unit, and the reflective region is located between adjacent insulating units; a plurality of LED units are disposed one-to-one on the plurality of connection units; wherein the substrate is electrically connected to the corresponding LED unit through the connection units, so that each LED unit can be driven individually.

[0008] In one possible implementation, the bonding layer includes: a first bonding layer disposed on a substrate, comprising a plurality of first connecting units, a plurality of first insulating units, and a first reflective region, wherein the plurality of first connecting units are arranged in an array on the substrate, each first connecting unit surrounds a first insulating unit, and the first reflective region is located between adjacent first insulating units; and a second bonding layer stacked and bonded to the first bonding layer, comprising a plurality of second connecting units corresponding one-to-one with the plurality of first connecting units, a plurality of second insulating units corresponding one-to-one with the plurality of first insulating units, and a second reflective region corresponding to the first reflective region; wherein the plurality of second connecting units are bonded one-to-one with the plurality of first connecting units to form the connecting units, the plurality of second insulating units are bonded one-to-one with the plurality of first insulating units to form the insulating units, and the second reflective region is bonded one-to-one with the first reflective region to form the reflective region.

[0009] In one possible implementation, the thickness of the first bonding layer is 0.3 μm to 0.5 μm; and / or, the thickness of the second bonding layer is 0.3 μm to 0.5 μm.

[0010] In one possible implementation, the micro LED display further includes: a passivation layer covering the surfaces of the plurality of LED units and the surface of the bonding layer exposed between adjacent LED units, the passivation layer having a first opening exposing at least a portion of the top surface of the LED unit; a conductive layer covering the passivation layer, the conductive layer being electrically connected to the LED unit through the first opening; a second opening penetrating the conductive layer and the passivation layer and at least exposing the reflective region; and a metal layer at least covering the second opening and connected to the reflective region.

[0011] In one possible implementation, the substrate includes: a driving circuit having a plurality of first electrode contacts and at least one second electrode contact, wherein the plurality of first electrode contacts are correspondingly and electrically connected to a plurality of connection units, and the second electrode contacts are electrically connected to the metal layer; the LED unit includes an LED epitaxial layer located above the connection unit, the LED epitaxial layer including a first semiconductor layer, a light-emitting layer and a second semiconductor layer stacked thereon; wherein the first electrode contacts are electrically connected through the first semiconductor layer of the LED unit corresponding to the connection unit, and the second semiconductor layers of the plurality of LED units are connected to the second electrode contacts through a conductive layer and the metal layer, so that each LED unit is driven individually.

[0012] In one possible implementation, the LED unit further includes a reflector layer and an electrode layer, wherein the reflector layer, the electrode layer and the LED epitaxial layer are stacked sequentially, and the reflector layer is connected to the corresponding connection unit.

[0013] In one possible implementation, the connecting unit is made of the same material as the reflective region, and the materials of the connecting unit and the reflective region include conductive materials; the insulating unit is made of insulating materials.

[0014] In one possible implementation, the spacing between adjacent connecting units is 1 μm to 2 μm; and / or, the width of the gap between adjacent insulating units is 0.3 μm to 0.5 μm.

[0015] In one possible implementation, the thickness of the reflector layer is 0.05 μm to 0.2 μm; and / or, the thickness of the electrode layer is 0.05 μm to 0.2 μm; and / or, the thickness of the LED epitaxial layer is 1 μm to 2 μm.

[0016] According to a second aspect of the embodiments of this application, a method for fabricating a micro light-emitting diode display is provided, comprising the following steps: providing a substrate; disposing a bonding layer on the substrate, wherein the bonding layer includes a plurality of connection units, a plurality of insulating units, and a reflective region, wherein the plurality of connection units are arranged in an array on the substrate, each connection unit is surrounded by an insulating unit, and the reflective region is located between adjacent insulating units; forming a plurality of LED units on the bonding layer, wherein the plurality of LED units are disposed one-to-one on the plurality of connection units; wherein the substrate is electrically connected to the corresponding LED unit through the connection units, so that each LED unit can be driven individually.

[0017] In one possible implementation, the step of forming a bonding layer on the substrate includes: forming a first bonding layer on the substrate, wherein the first bonding layer includes a plurality of first connecting units, a plurality of first insulating units, and a first reflective region, the plurality of first connecting units being arranged in an array on the substrate, each first connecting unit surrounding a first insulating unit, and the first reflective region being located between adjacent first insulating units; providing a substrate on which an LED epitaxial layer structure is disposed; forming a second bonding layer above the LED epitaxial layer structure, wherein the second bonding layer includes a plurality of second connecting units corresponding one-to-one with the plurality of first connecting units, a plurality of second insulating units corresponding one-to-one with the plurality of first insulating units, and a second reflective region corresponding to the first reflective region; bonding the second bonding layer to the first bonding layer to form the bonding layer, wherein the plurality of second connecting units are bonded one-to-one with the plurality of first connecting units to form the connecting units, the plurality of second insulating units are bonded one-to-one with the plurality of first insulating units to form the insulating units, and the second reflective region is bonded one-to-one with the first reflective region to form the reflective region.

[0018] In one possible implementation, the step of forming a plurality of LED units on the bonding layer includes: removing the substrate; etching the LED epitaxial layer structure to form a plurality of LED units, the LED units being located above the corresponding bonding units.

[0019] In one possible implementation, an electrode layer structure and a mirror layer structure are sequentially formed on the LED epitaxial layer structure, and a second bonding layer is formed on the surface of the mirror layer structure facing away from the electrode layer structure. The step of forming multiple LED units on the bonding layer further includes: etching the electrode layer structure to form an electrode layer; etching the mirror layer structure to form a mirror layer, wherein the mirror layer is connected to the corresponding connection unit.

[0020] In one possible implementation, the step of forming a first bonding layer on the substrate includes: forming a first conductive material layer on the substrate; etching the first conductive material layer to form a plurality of first connection units arranged in an array, wherein each first connection unit is surrounded by a first annular hole, and the first conductive material layer located between adjacent first annular holes forms a first reflective region; and forming a first insulating unit in the first annular hole to obtain the first bonding layer; the step of forming a second bonding layer above the LED epitaxial layer structure includes: forming a second conductive material layer above the LED epitaxial layer structure; etching the second conductive material layer to form a plurality of second connection units corresponding one-to-one with the plurality of first connection units, a plurality of second annular holes corresponding one-to-one with the plurality of first insulating units, and a second reflective region corresponding to the first reflective region; and forming a second insulating unit in the second annular hole to obtain the second bonding layer.

[0021] In one possible implementation, the fabrication method further includes: forming a passivation layer covering the surfaces of a plurality of LED units and the surface of the bonding layer exposed between adjacent LED units; forming a first opening in the passivation layer, the first opening exposing at least a portion of the top surface of the LED unit; forming a conductive layer covering the passivation layer and electrically connected to the LED unit through the first opening; forming a second opening in the conductive layer and the passivation layer, the second opening at least exposing the reflective region; and forming a metal layer at least covering the second opening and connected to the reflective region.

[0022] The miniature light-emitting diode display and its fabrication method provided in this application can achieve at least the following technical effects:

[0023] In this application, a bonding layer is disposed on a substrate. The bonding layer includes multiple connection units, multiple insulating units, and a reflective region. The multiple connection units are arranged in an array on the substrate, with an insulating unit surrounding each connection unit to reduce optical crosstalk. The reflective region is located between adjacent insulating units and serves to reflect light, thereby improving the brightness of the display. Multiple LED units are correspondingly disposed on the multiple connection units, and the substrate is electrically connected to the multiple LED units through the multiple connection units. That is, the substrate is electrically connected to the corresponding LED unit through the connection units, so that each LED unit can be driven individually. Electrical and optical isolation is achieved by the insulating units surrounding the connection units and the reflective region disposed between two adjacent insulating units, reducing optical crosstalk and improving the brightness of the display.

[0024] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0025] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein:

[0026] Figure 1 A schematic diagram of the planar structure of a miniature light-emitting diode display provided in an embodiment of this disclosure;

[0027] Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure along line A1-A2 provided in the illustrated embodiment;

[0028] Figure 3 A schematic structural diagram of a substrate provided in an embodiment of this disclosure;

[0029] Figure 4 A schematic structural diagram of a first conductive material layer (with a first annular hole) formed on a substrate, provided for an embodiment of this disclosure;

[0030] Figure 5 In order to be in Figure 4 The illustrated embodiment provides a schematic structural diagram of the deposition of insulating material on the structure;

[0031] Figure 6 In order to be in Figure 5 The illustrated embodiment provides a schematic structural diagram of the first bonding layer.

[0032] Figure 7 A schematic structural diagram of the substrate, LED epitaxial layer structure, electrode layer structure, mirror layer structure, and second conductive material layer provided in the embodiments of this disclosure;

[0033] Figure 8 In order to be in Figure 7 The illustrated embodiment provides a schematic structural diagram of a structure forming a second annular hole.

[0034] Figure 9 In order to be in Figure 8 The illustrated embodiment provides a schematic structural diagram of the deposition of insulating material on the structure;

[0035] Figure 10 In order to be in Figure 9 The illustrated embodiment provides a schematic structural diagram of the second bonding layer.

[0036] Figure 11 To be Figure 10 The second bonding layer of the provided structure is bonded to Figure 6 A schematic structural diagram of the first bonding layer of the provided structure;

[0037] Figure 12 In order to be in Figure 11 The illustrated embodiment provides a schematic structural diagram of a substrate removal structure.

[0038] Figure 13 In order to be in Figure 12 The illustrated embodiment provides a schematic structural diagram of an LED unit formed thereon.

[0039] Figure 14 This is a schematic diagram of the planar structure of the bonding layer provided in an embodiment of the present disclosure;

[0040] Figure 15 In order to be in Figure 13 The illustrated embodiment provides a schematic structural diagram of a structure in which a passivation layer is formed.

[0041] Figure 16 In order to be in Figure 15 The illustrated embodiment provides a schematic structural diagram of a structure in which a conductive layer is formed.

[0042] Figure 17 A schematic structural diagram of a display device provided in an embodiment of this disclosure;

[0043] Figure 18 A flowchart illustrating a method for fabricating a miniature light-emitting diode display according to an embodiment of this disclosure;

[0044] Figure 19 A flowchart illustrating a method for fabricating a miniature light-emitting diode display according to another embodiment of this disclosure.

[0045] The reference numerals in the attached figures are as follows:

[0046] 100: Miniature LED display;

[0047] 101: Substrate; 102: First electrode contact; 103: Bonding layer; 1031: Connecting unit; 1032: Insulating unit; 1033: Reflective region; 104: LED unit; 1041: Mirror layer; 1042: Electrode layer; 1043: LED epitaxial layer; 105: First bonding layer; 1051: First connecting unit; 1052: First insulating unit; 1053: First reflective region; 1054: First annular hole; 106: ... Two bonding layers; 1061: Second connection unit; 1062: Second insulating unit; 1063: Second reflective region; 1064: Second annular hole; 107: Metal layer; 108: Passivation layer; 109: Conductive layer; 110: Substrate; 111: LED epitaxial layer structure; 112: Electrode layer structure; 113: Mirror layer structure; 114: First conductive material layer; 115: Second conductive material layer; 116: First opening; 117: Second opening;

[0048] 200: Display device. Detailed Implementation

[0049] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0050] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0051] In this disclosure, the terms "upper," "lower," "inner," "middle," "outer," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for better describing the embodiments of this disclosure and their implementations, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to require them to be constructed and operated in a specific orientation. Furthermore, some of the aforementioned terms may be used to indicate other meanings besides orientation or positional relationship; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this disclosure according to the specific circumstances.

[0052] Furthermore, the terms "set up," "connect," and "fix" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0053] Unless otherwise stated, the term "multiple" means two or more.

[0054] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0055] It should be noted that, unless otherwise specified, the embodiments and features described in the present disclosure can be combined with each other.

[0056] It should be noted that, as used in the embodiments of this disclosure, the term "layer" refers to a portion of material comprising a region having a certain thickness. A layer may extend over the entire lower or upper structure, or may have a extent smaller than that of the lower or upper structure. Furthermore, a layer may be a region of a homogeneous or heterogeneous continuous structure, with a thickness less than the thickness of the continuous structure. For example, a layer may be located between the top and bottom surfaces of a continuous structure, or between any pair of horizontal planes therebetween. A layer may extend horizontally, vertically, and / or along a conical surface.

[0057] It should be noted that the term "micro" as used in the embodiments of this disclosure refers to the descriptive size of certain devices or structures according to the embodiments of this application. The term "micro" as used herein is intended to indicate a scale from 0.1 μm to 100 μm. However, it should be understood that the embodiments of this application are not necessarily limited thereto, and certain aspects of the embodiments can be applied to larger and possibly smaller size scales.

[0058] like Figures 1 to 16 As shown, this embodiment of the present disclosure provides a miniature light-emitting diode display 100, including a substrate 101, a bonding layer 103, and a plurality of LED units 104. The bonding layer 103 is disposed on the substrate 101 and includes a plurality of connection units 1031, a plurality of insulating units 1032, and a reflective region 1033. The plurality of connection units 1031 are arranged in an array on the substrate 101. Each connection unit 1031 is surrounded by an insulating unit 1032. The reflective region 1033 is located between adjacent insulating units 1032. The plurality of LED units 104 are correspondingly disposed on the plurality of connection units 1031. The substrate 101 is electrically connected to the corresponding LED unit 104 through the connection units 1031, so that each LED unit 104 can be driven individually.

[0059] A bonding layer 103 is disposed on a substrate 101, specifically on the top surface of the substrate 101. The bonding layer 103 includes a plurality of connecting units 1031, a plurality of insulating units 1032, and a reflective region 1033. The plurality of connecting units 1031 are arranged in an array on the substrate 101, and an insulating unit 1032 surrounds the outside of each connecting unit 1031. That is, the plurality of insulating units 1032 are arranged one-to-one around the outside of the plurality of connecting units 1031 to reduce optical crosstalk.

[0060] The reflective region 1033 is located between adjacent insulating units 1032. The reflective region 1033 serves a reflective function to improve the brightness of the display. That is, there are gaps between adjacent insulating units 1032, and the reflective region 1033 fills at least the gaps between multiple insulating units 1032. Specifically, insulating units 1032 are respectively provided on opposite sides of the reflective region 1033, forming a structure where insulating units 1032, reflective regions 1033, and insulating units 1032 are arranged sequentially between two adjacent connecting units 1031 to achieve electrical and optical isolation. This embodiment achieves electrical and optical isolation, reduces optical crosstalk, and improves the brightness of the display by using insulating units 1032 surrounding the connecting unit 1031 and reflective regions 1033 disposed between two adjacent insulating units 1032. For example, when the pixel pitch is reduced to a few micrometers, the micro-LED display 100 of this embodiment can improve brightness and reduce optical crosstalk.

[0061] Multiple LED units 104 are disposed on multiple connecting units 1031 in a one-to-one correspondence. That is, multiple LED units 104 are disposed on the top surface of multiple connecting units 1031 in a one-to-one correspondence. Multiple LED units 104 are electrically connected to multiple connecting units 1031 in a one-to-one correspondence. The substrate 101 is electrically connected to the corresponding multiple LED units 104 through multiple connecting units 1031 so that each LED unit 104 can be driven individually.

[0062] In this embodiment, substrate 101 refers to the material on which subsequent material layers are added. Substrate 101 itself may be patterned. The material added to the top of substrate 101 may be patterned or may remain unpatterned. Furthermore, substrate 101 may include a wide variety of semiconductor materials, such as silicon, silicon carbide, gallium nitride, germanium, gallium arsenide, and indium phosphide. Alternatively, substrate 101 may be made of a non-conductive material, such as glass, plastic, or sapphire wafer. Further alternatively, substrate 101 may have semiconductor devices or circuits formed therein.

[0063] Combination Figure 2 , Figures 4 to 6 , Figures 8 to 13 , Figure 15 and Figure 16As shown, in some embodiments, the bonding layer 103 includes a first bonding layer 105 and a second bonding layer 106. The first bonding layer 105 is disposed on the substrate 101 and includes a plurality of first connection units 1051, a plurality of first insulating units 1052, and a first reflective region 1053. The plurality of first connection units 1051 are arranged in an array on the substrate 101, with a first insulating unit 1052 surrounding the outside of each first connection unit 1051, and the first reflective region 1053 is located between adjacent first insulating units 1052. The second bonding layer 106 is stacked and bonded to the first bonding layer 105. The second bonding layer 106 includes a plurality of second connection units 1061 corresponding one-to-one with the plurality of first connection units 1051, a plurality of second insulating units 1062 corresponding one-to-one with the plurality of first insulating units 1052, and a second reflective region 1063 corresponding to the first reflective region 1053. In this configuration, multiple second connecting units 1061 are bonded one-to-one with multiple first connecting units 1051 to form connecting units 1031, multiple second insulating units 1062 are bonded one-to-one with multiple first insulating units 1052 to form insulating units 1032, and a second reflective region 1063 is bonded to a first reflective region 1053 to form a reflective region 1033.

[0064] The bonding layer 103 includes a first bonding layer 105 and a second bonding layer 106. The first bonding layer 105 is disposed on the substrate 101, that is, on the top surface of the substrate 101. The first bonding layer 105 includes a plurality of first connecting units 1051, a plurality of first insulating units 1052, and a first reflective region 1053. The plurality of first connecting units 1051 are arranged in an array on the substrate 101. Each first connecting unit 1051 is surrounded by a first insulating unit 1052, that is, the plurality of first insulating units 1052 are arranged in a one-to-one correspondence around the outside of the plurality of first connecting units 1051, thereby reducing optical crosstalk. There are gaps between adjacent first insulating units 1052. The first reflective region 1053 at least fills the gaps between the plurality of first insulating units 1052, thereby achieving electrical and optical isolation, reducing optical crosstalk, and improving brightness.

[0065] The second bonding layer 106 is stacked and bonded onto the first bonding layer 105. Specifically, the second bonding layer 106 and the first bonding layer 105 are stacked and the second bonding layer 106 is located on the top surface of the first bonding layer 105. The second bonding layer 106 includes a plurality of second connecting units 1061 corresponding to a plurality of first connecting units 1051, a plurality of second insulating units 1062 corresponding to a plurality of first insulating units 1052, and a second reflecting region 1063 corresponding to a first reflecting region 1053, so as to realize the mixed bonding of the second bonding layer 106 and the first bonding layer 105 to form a bonding layer 103. Specifically, the second bonding layer 106 includes a plurality of second connecting units 1061, a plurality of second insulating units 1062, and a second reflective region 1063. The plurality of second connecting units 1061 are arranged in an array on the first bonding layer 105, and a second insulating unit 1062 surrounds the outside of each second connecting unit 1061. That is, the plurality of second insulating units 1062 are arranged in a one-to-one correspondence around the outside of the plurality of second connecting units 1061 to reduce optical crosstalk. The second reflective region 1063 is located between adjacent second insulating units 1062 to achieve electrical and optical isolation, reduce optical crosstalk, and improve brightness.

[0066] Furthermore, when the second bonding layer 106 and the first bonding layer 105 are mixed-bonded, multiple second connecting units 1061 are bonded one-to-one with multiple first connecting units 1051 to form connecting units 1031, multiple second insulating units 1062 are bonded one-to-one with multiple first insulating units 1052 to form insulating units 1032, and the second reflective region 1063 is bonded one-to-one with the first reflective region 1053 to form reflective region 1033. Through the mixed bonding technology, electrical and optical isolation regions are simultaneously set in the bonding layer 103, reducing optical crosstalk and improving brightness. Alternatively, the second bonding layer 106 and the first bonding layer 105 can be mixed-bonded to form the bonding layer 103, achieving a firm connection between the second bonding layer 106 and the first bonding layer 105, improving the stability of the bonding layer 103, achieving stress release, and reducing bond warpage.

[0067] In one possible implementation, the first connecting unit 1051 and the first reflective region 1053 are made of the same material, and the materials of the first connecting unit 1051 and the first reflective region 1053 include a conductive material, which includes a gold-tin alloy (AuSn). The first insulating unit 1052 is made of an insulating material, which includes silicon dioxide (SiO2).

[0068] In one possible implementation, the second connecting unit 1061 is made of the same material as the second reflective region 1063, and the materials of the second connecting unit 1061 and the second reflective region 1063 include conductive materials, such as a gold-tin alloy (AuSn). The material of the second insulating unit 1062 includes insulating materials, such as silicon dioxide (SiO2).

[0069] For example, the materials of the first connecting unit 1051, the first reflective region 1053, the second connecting unit 1061, and the second reflective region 1063 are gold-tin alloys, respectively. The materials of the first insulating unit 1052 and the second insulating unit 1062 are silicon dioxide, respectively. When the second bonding layer 106 and the first bonding layer 105 are mixed-bonded, the gold-tin alloy material region of the second bonding layer 106 is bonded to the gold-tin alloy material region of the first bonding layer 105, and the silicon dioxide material region of the second bonding layer 106 is bonded to the silicon dioxide material region of the first bonding layer 105, thereby achieving mixed bonding. This effectively avoids or reduces optical crosstalk, improves brightness, and also enables stress release, reducing bond warpage.

[0070] Combination Figure 13 As shown, in some embodiments, the thickness of the first bonding layer 105 is 0.3 μm to 0.5 μm.

[0071] Figure 13 a1 in the figure is used to indicate the thickness of the first bonding layer 105. The thickness of the first bonding layer 105 is 0.3μm to 0.5μm, which improves the connection strength and conductivity stability.

[0072] Combination Figure 13 As shown, in some embodiments, the thickness of the second bonding layer 106 is 0.3 μm to 0.5 μm.

[0073] Figure 13 a2 in the figure is used to indicate the thickness of the second bonding layer 106. The thickness of the second bonding layer 106 is 0.3 μm to 0.5 μm, which improves the connection strength and conductivity stability.

[0074] Combination Figure 13 As shown, in some embodiments, the thickness of the first bonding layer 105 is 0.3 μm to 0.5 μm. The thickness of the second bonding layer 106 is 0.3 μm to 0.5 μm.

[0075] By using the thicknesses of the first bonding layer 105 and the second bonding layer 106, which are 0.3 μm to 0.5 μm respectively, the stable bonding between the second bonding layer 106 and the first bonding layer 105 is improved, thereby enhancing the hybrid bonding effect.

[0076] In one possible implementation, the thickness of the first bonding layer 105 is 0.3 μm, 0.4 μm, 0.5 μm, or other values ​​between 0.3 μm and 0.5 μm.

[0077] In one possible implementation, the thickness of the second bonding layer 106 is 0.3 μm, 0.4 μm, 0.5 μm, or other values ​​between 0.3 μm and 0.5 μm.

[0078] Combination Figure 1 , Figure 2 , Figure 15 and Figure 16 As shown, in some embodiments, the micro LED display 100 further includes a passivation layer 108, a conductive layer 109, and a metal layer 107. The passivation layer 108 covers the surfaces of a plurality of LED cells 104 and the surfaces of the bonding layers 103 exposed between adjacent LED cells 104. The passivation layer 108 has a first opening 116 that exposes at least a portion of the top surface of the LED cells 104. The conductive layer 109 covers the passivation layer 108 and is electrically connected to the LED cells 104 through the first opening 116. A second opening 117 penetrates the conductive layer 109 and the passivation layer 108 and exposes at least the top surface of the reflective region 1033. The metal layer 107 at least covers the second opening 117 and is connected to the reflective region 1033.

[0079] Specifically, the micro LED display 100 further includes a passivation layer 108, a conductive layer 109, and a metal layer 107. The passivation layer 108 covers the surfaces of the plurality of LED units 104 and the surfaces of the exposed bonding layers 103 between adjacent LED units 104, protecting the LED units 104 and stabilizing the electrical performance of the display. The passivation layer 108 has a first opening 116 that exposes at least a portion of the top surface of the LED unit 104; that is, in the vertical direction, a portion of the passivation layer 108 is removed to expose at least a portion of the top surface of the LED unit 104. In this embodiment, the vertical direction is the direction perpendicular to the top surface of the substrate 101, which will not be described further below.

[0080] The second opening 117 penetrates the conductive layer 109 and the passivation layer 108. The second opening 117 exposes at least the top surface of the reflective region 1033. That is, in the vertical direction, a portion of the conductive layer 109 and the passivation layer 108 are removed so that the second opening 117 exposes at least the top surface of the reflective region 1033 to reduce optical crosstalk.

[0081] The metal layer 107 at least covers the second opening 117 and is connected to the reflective region 1033. The metal layer 107 reduces the series resistance of the conductive layer 109 and further isolates optical crosstalk through the reflective region 1033 and the metal layer 107 located on top of the reflective region 1033. The conductive layer 109 and the metal layer 107 are also used to realize the electrical connection between the LED unit 104 and the substrate 101.

[0082] In one possible implementation, the material of the metal layer 107 includes, but is not limited to, gold, silver, or copper.

[0083] In one possible implementation, the material of the passivation layer 108 includes an insulating material, such as SiO2.

[0084] In one possible implementation, the material of the conductive layer 109 includes indium tin oxide (ITO).

[0085] In some embodiments, the connecting unit 1031 and the reflective region 1033 are made of the same material, and the materials of the connecting unit 1031 and the reflective region 1033 include conductive materials. The insulating unit 1032 is made of insulating material.

[0086] Specifically, the connecting unit 1031 and the reflective region 1033 are made of the same material, which includes a conductive material, such as a gold-tin alloy (AuSn), to achieve electrical connection between the substrate 101 and the LED unit 104 through the connecting unit 1031. The insulating unit 1032 is made of an insulating material, such as silicon dioxide (SiO2), to achieve electrical and optical isolation between the insulating unit 1032 and the reflective region 1033, reducing optical crosstalk and improving the brightness of the display.

[0087] Combination Figure 2 As shown, in some embodiments, the spacing between adjacent connection units 1031 is 1 μm to 2 μm.

[0088] Figure 2 b1 in the diagram is used to indicate the spacing between two adjacent connection units 1031. By setting the spacing between adjacent connection units to 1μm to 2μm, more LED units 104 can be accommodated within a unit area.

[0089] In one possible implementation, the spacing between adjacent connection units 1031 is 1 μm, 1.2 μm, 1.5 μm, 1.8 μm, 2 μm, or other values ​​between 1 μm and 2 μm.

[0090] In some embodiments, the width of the gap between adjacent insulating units 1032 is 0.3 μm to 0.5 μm.

[0091] Figure 2 b2 in the figure is used to define the width of the gap between adjacent insulating units 1032, and also the width of the reflective region 1033 between adjacent insulating units 1032. By using a gap width of 0.3 μm to 0.5 μm between adjacent insulating units 1032, optical crosstalk can be reduced and the brightness of the display can be improved.

[0092] In one possible implementation, the width of the gap between adjacent insulating units 1032 is 0.3 μm, 0.4 μm, 0.5 μm, or other values ​​between 0.3 μm and 0.5 μm.

[0093] For example, in combination Figure 2 As shown, the width of the connecting unit 1031 is 2.5 μm, the spacing (b1) between two adjacent connecting units 1031 is 1.5 μm, the width (b2) of the gap between adjacent insulating units 1032 is 0.5 μm, and the width of the insulating unit 1032 is 0.5 μm.

[0094] Combination Figure 2 , Figure 13 , Figure 15 and Figure 16 As shown, in some embodiments, the LED unit 104 further includes a reflector layer 1041 and an electrode layer 1042, wherein the reflector layer 1041, the electrode layer 1042 and the LED epitaxial layer 1043 are stacked sequentially, and the reflector layer 1041 is connected to the corresponding connection unit 1031.

[0095] Specifically, a reflector layer 1041 is disposed on the top surface of the corresponding connection unit 1031, an electrode layer 1042 is stacked on the top surface of the reflector layer 1041, and an LED epitaxial layer 1043 is stacked on the top surface of the electrode layer 1042. The reflector layer 1041 improves reflectivity, reduces optical crosstalk, and achieves optical isolation. When the LED unit 104 is working, the electrode layer 1042 enables current to be injected into the LED epitaxial layer 1043, causing the LED epitaxial layer 1043 to emit light.

[0096] In one possible implementation, the material of the mirror layer 1041 includes silver (Ag).

[0097] In one possible implementation, the electrode layer 1042 is made of indium tin oxide (ITO). Indium tin oxide (ITO) is a transparent conductive material, which improves light transmittance through the transparent electrode layer 1042.

[0098] In one possible implementation, the material of the LED epitaxial layer 1043 includes gallium nitride (GaN).

[0099] Combination Figure 13As shown, in some embodiments, the thickness of the reflector layer 1041 is 0.05 μm to 0.2 μm. And / or, the thickness of the electrode layer 1042 is 0.05 μm to 0.2 μm. And / or, the thickness of the LED epitaxial layer 1043 is 1 μm to 2 μm.

[0100] Figure 13 In the diagram, c1 indicates the thickness of the reflector layer 1041, c2 indicates the thickness of the electrode layer 1042, and c3 indicates the thickness of the LED epitaxial layer 1043.

[0101] The thickness of the reflective layer 1041 is 0.05μm to 0.2μm, which enables effective reflection of light and improves brightness.

[0102] The electrode layer 1042 has a thickness of 0.05 μm to 0.2 μm, enabling efficient current injection and conduction.

[0103] The thickness of the 1043 epitaxial layer in LEDs is 1μm to 2μm, which improves luminous efficiency and brightness.

[0104] In one possible implementation, the thickness of the mirror layer 1041 is 0.05 μm, 0.1 μm, 0.15 μm, 0.2 μm, or other values ​​between 0.05 μm and 0.2 μm.

[0105] In one possible implementation, the thickness of the electrode layer 1042 is 0.05 μm, 0.1 μm, 0.15 μm, 0.2 μm, or other values ​​between 0.05 μm and 0.2 μm.

[0106] In one possible implementation, the thickness of the LED epitaxial layer 1043 is 1 μm, 1.3 μm, 1.5 μm, 1.8 μm, 2 μm, or other values ​​between 1 μm and 2 μm.

[0107] In some embodiments, the LED epitaxial layer 1043 includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked together. The first semiconductor layer may be a p-type semiconductor layer, and the second semiconductor layer may be an n-type semiconductor layer. The p-type semiconductor layer is disposed on the top surface of the electrode layer 1042, and the p-type semiconductor layer may be formed by doping or ion implantation, for example, p-type GaN. The n-type semiconductor layer may be formed by doping or ion implantation, for example, n-type GaN. The light-emitting layer may be a single quantum well structure or a multi-quantum well structure, used to combine holes and electrons to output light of a specific wavelength.

[0108] In some embodiments, the substrate 101 includes a driving circuit having a plurality of first electrode contacts 102 and at least one second electrode contact (not shown in the figure). The plurality of first electrode contacts 102 are correspondingly disposed and electrically connected to a plurality of connection units 1031, and the second electrode contacts are electrically connected to the metal layer 107. The LED unit 104 includes an LED epitaxial layer 1043 located above the connection unit 1031. The LED epitaxial layer 1043 includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked together. The first electrode contacts 102 are electrically connected to the first semiconductor layer of the LED unit 104 corresponding to the connection unit 1031. The second semiconductor layers of the plurality of LED units 104 are connected to the second electrode contacts through a conductive layer 109 and a metal layer 107, so that each LED unit 104 is driven individually, that is, any one of the plurality of LED units 104 is driven to emit light individually by the substrate 101.

[0109] It should be noted that the substrate 101 may be provided with circuit layers including complementary metal oxide semiconductor (CMOS) devices or thin film field effect transistor (TFT) devices, and these CMOS devices or TFT devices can constitute driving circuits.

[0110] For example, such as Figure 2 As shown, Figure 2 The first electrode contact 102 is the anode electrode contact, and the second electrode contact is the cathode electrode contact. In this example, multiple anode electrode contacts are arranged one-to-one below multiple connection units 1031, so that the multiple anode electrode contacts correspond one-to-one with and are independently electrically connected to the p-type semiconductor layers of multiple LED units 104. The n-type semiconductor layers of multiple LED units 104 are connected to the cathode electrode contacts through conductive layer 109 and metal layer 107 to form a common cathode structure. In practical applications, an anode voltage can be applied to the p-type semiconductor layer to drive the light-emitting layer to emit light, so that each LED unit 104 can be driven individually.

[0111] like Figures 1 to 17 As shown, this disclosure also provides a display device 200. The display device 200 includes a miniature light-emitting diode display 100 as described in any of the preceding embodiments.

[0112] In this embodiment, the display device 200 includes the micro LED display 100 as in any of the previous embodiments, and therefore has all the beneficial effects of the micro LED display 100 as in any of the previous embodiments, which will not be described in detail hereafter.

[0113] It should be noted that the micro LED display 100 or display device 200 can be applied to augmented reality (AR) display devices, virtual reality (VR) display devices, near-eye display (NED) devices, head-up display (HUD) devices, etc.

[0114] Combination Figures 1 to 18 As shown, according to a second aspect of the embodiments of this application, a method for fabricating a miniature light-emitting diode display 100 is provided, comprising the following steps:

[0115] S181, Provide a substrate.

[0116] like Figure 3 As shown, the substrate 101 enables each LED unit 104 to be driven individually.

[0117] S182. A bonding layer is provided on the substrate, wherein the bonding layer includes multiple connecting units, multiple insulating units and a reflective region, the multiple connecting units are arranged in an array on the substrate, each connecting unit is surrounded by an insulating unit, and the reflective region is located between adjacent insulating units.

[0118] like Figure 13 and Figure 14 As shown, a bonding layer 103 is provided on the substrate 101 to connect the substrate 101 to the LED unit 104. The beneficial effects of the bonding layer 103 are described in the foregoing embodiments of this application and will not be repeated here.

[0119] S183. Multiple LED units are formed on the bonding layer, wherein the multiple LED units are disposed on multiple connection units in a one-to-one correspondence; wherein the substrate is electrically connected to the corresponding LED unit through the connection unit so that each LED unit can be driven individually.

[0120] The micro LED display 100 prepared by the method in this embodiment achieves electrical and optical isolation, reduces optical crosstalk, and improves brightness.

[0121] like Figures 4 to 12As shown, in some embodiments, the step of forming a bonding layer 103 on a substrate 101 includes: forming a first bonding layer 105 on the substrate 101, wherein the first bonding layer 105 includes a plurality of first connection units 1051, a plurality of first insulating units 1052, and a first reflective region 1053. The plurality of first connection units 1051 are arranged in an array on the substrate 101, and a first insulating unit 1052 surrounds the outside of each first connection unit 1051. The first reflective region 1053 is located between adjacent first insulating units 1052. A substrate 110 is provided, and an LED epitaxial layer structure 111 is disposed on the substrate 110. A second bonding layer 106 is formed above the LED epitaxial layer structure 111, wherein the second bonding layer 106 includes a plurality of second connection units 1061 corresponding one-to-one with the plurality of first connection units 1051, a plurality of second insulating units 1062 corresponding one-to-one with the plurality of first insulating units 1052, and a second reflective region 1063 corresponding to the first reflective region 1053. The second bonding layer 106 is bonded to the first bonding layer 105 to form a bonding layer 103. A plurality of second connecting units 1061 are bonded to a plurality of first connecting units 1051 in a one-to-one correspondence to form connecting units 1031. A plurality of second insulating units 1062 are bonded to a plurality of first insulating units 1052 in a one-to-one correspondence to form insulating units 1032. A second reflective region 1063 is bonded to a first reflective region 1053 in a corresponding manner to form a reflective region 1033.

[0122] A first bonding layer 105 is formed on the substrate 101. Specifically, the first bonding layer 105 includes a plurality of first connection units 1051, a plurality of first insulating units 1052, and a first reflective region 1053. The plurality of first connection units 1051 are arranged in an array on the substrate 101. Each first connection unit 1051 is surrounded by a first insulating unit 1052. The first reflective region 1053 is located between adjacent first insulating units 1052 to reduce optical crosstalk and improve brightness.

[0123] A substrate 110 is provided, on which an LED epitaxial layer structure 111 is disposed. Specifically, an LED epitaxial layer structure 111, an electrode layer structure 112, and a reflector layer structure 113 are sequentially stacked on the substrate 110. The LED epitaxial layer structure 111 is grown on the substrate 110 to provide an LED epitaxial layer 1043 for light emission. The electrode layer structure 112 is deposited on the LED epitaxial layer structure 111 to provide an electrode layer 1042 for providing a current injection path. The reflector layer structure 113 is deposited on the electrode layer structure 112 to provide a reflector layer 1041 for enhancing the brightness of the display.

[0124] A second bonding layer 106 is formed above the LED epitaxial layer structure 111. The second bonding layer 106 includes a plurality of second connecting units 1061 corresponding to a plurality of first connecting units 1051, a plurality of second insulating units 1062 corresponding to a plurality of first insulating units 1052, and a second reflecting region 1063 corresponding to a first reflecting region 1053, so as to realize the mixed bonding of the second bonding layer 106 and the first bonding layer 105.

[0125] The second bonding layer 106 is bonded to the first bonding layer 105 to form a bonding layer 103. Multiple second connecting units 1061 are bonded one-to-one with multiple first connecting units 1051 to form connecting units 1031; multiple second insulating units 1062 are bonded one-to-one with multiple first insulating units 1052 to form insulating units 1032; and a second reflective region 1063 is bonded to a corresponding first reflective region 1053 to form a reflective region 1033, achieving hybrid bonding. This hybrid bonding method effectively avoids or reduces optical crosstalk, improves display brightness, and also achieves stress relief and reduces bond warpage.

[0126] In one possible implementation, the material of the substrate 110 includes, but is not limited to, silicon and sapphire.

[0127] In some embodiments, the step of forming a plurality of LED units 104 on the bonding layer 103 includes: removing the substrate 110; etching the LED epitaxial layer structure 111 to form a plurality of LED units 104, wherein the LED units 104 are located above the corresponding connection units 1031.

[0128] In some embodiments, an electrode layer structure 112 and a mirror layer structure 113 are sequentially formed on the LED epitaxial layer structure 111, and a second bonding layer 106 is formed on the surface of the mirror layer structure 113 facing away from the electrode layer structure 112. The step of forming a plurality of LED units 104 on the bonding layer 103 further includes: etching the electrode layer structure 112 to form an electrode layer 1042; etching the mirror layer structure 113 to form a mirror layer 1041; and connecting the mirror layer 1041 to a corresponding connection unit 1031.

[0129] Combination Figure 11 and Figure 12 As shown, after the second bonding layer 106 is bonded to the first bonding layer 105, a mirror layer structure 113, an electrode layer structure 112, an LED epitaxial layer structure 111, and a substrate 110 are sequentially disposed on the side of the second bonding layer 106 facing away from the first bonding layer 105. The substrate 110 is removed to facilitate the fabrication of the LED unit 104. Specifically, the substrate 110 can be removed by a dry method or a wet method.

[0130] The LED epitaxial layer structure 111, electrode layer structure 112, and mirror layer structure 113 are etched to obtain the corresponding LED epitaxial layer 1043, electrode layer 1042, and mirror layer 1041, forming multiple LED units 104. These multiple LED units 104 are then disposed one-to-one on multiple connection units 1031. Specifically, the required pattern is formed on the surface of the LED epitaxial layer structure 111 using photolithography to provide a mask for subsequent etching steps. Then, the LED epitaxial layer structure 111, electrode layer structure 112, and mirror layer structure 113 are etched using chemical or physical etching methods to obtain multiple LED units 104, which are then disposed one-to-one on multiple connection units 1031.

[0131] Combination Figures 4 to 6 As shown, in some embodiments, the step of forming a first bonding layer 105 on the substrate 101 includes: forming a first conductive material layer 114 on the substrate 101; etching the first conductive material layer 114 to form a plurality of first connection units 1051 arranged in an array, and each first connection unit 1051 is surrounded by a first annular hole 1054, with the first conductive material layer 114 located between adjacent first annular holes 1054 forming a first reflective region 1053; and forming a first insulating unit 1052 in the first annular hole 1054 to obtain the first bonding layer 105.

[0132] Specifically, a first conductive material layer 114 is formed on the substrate 101, and the first conductive material layer 114 is etched to form a plurality of first connection units 1051 arranged in an array. Each first connection unit 1051 is surrounded by a first annular hole 1054. Specifically, the first conductive material layer 114 can be patterned by photolithographic metal lift-off or photolithographic metal etching to obtain a plurality of first annular holes 1054 arranged at intervals. The area of ​​the first conductive material layer 114 surrounding each first annular hole 1054 is the first connection unit 1051. The first conductive material layer 114 located between adjacent first annular holes 1054 forms a first reflective region 1053.

[0133] An insulating material is deposited on the first conductive material layer 114, filling the first annular hole 1054. The insulating material on the top surface of the first conductive material layer 114 can be removed by chemical mechanical polishing (CMP), and the top surface of the insulating material filling the first annular hole 1054 is made flush with the top surface of the first conductive material layer 114 to form a plurality of first insulating units 1052, thereby obtaining the first bonding layer 105.

[0134] Furthermore, by having the first insulating unit 1052 disposed within the first bonding layer 105, the number of metal etching steps can be reduced during etching, thereby improving efficiency.

[0135] In one possible implementation, such as Figure 5 As shown, Figure 5 In the figure, d1 is used to indicate the thickness of the insulating material deposited on the top surface of the first conductive material layer 114. The thickness of the insulating material deposited on the top surface of the first conductive material layer 114 is 2 μm to 4 μm, so that the first annular hole 1054 is filled with insulating material, thereby improving the hybrid bonding effect.

[0136] In one possible implementation, the material of the first conductive material layer 114 includes a gold-tin alloy. The first conductive material layer 114 can be formed on the top surface of the substrate 101 by deposition.

[0137] Combination Figures 7 to 10 As shown, in some embodiments, the step of forming a second bonding layer 106 above the LED epitaxial layer structure 111 includes: forming a second conductive material layer 115 above the LED epitaxial layer structure 111; etching the second conductive material layer 115 to form a plurality of second connection units 1061 corresponding to a plurality of first connection units 1051, a plurality of second annular holes 1064 corresponding to a plurality of first insulating units 1052, and a second reflective region 1063 corresponding to a first reflective region 1053; and forming second insulating units 1062 in the second annular holes 1064 to obtain the second bonding layer 106.

[0138] A second conductive material layer 115 is formed on the mirror layer structure 113. Specifically, the second conductive material layer 115 is deposited on the mirror layer structure 113.

[0139] The second conductive material layer 115 is etched to form a plurality of second connection units 1061 corresponding to a plurality of first connection units 1051, a plurality of second annular holes 1064 corresponding to a plurality of first insulating units 1052, and a second reflective region 1063 corresponding to a first reflective region 1053. Specifically, the second conductive material layer 115 can be patterned by photolithographic metal lift-off or photolithographic metal etching to obtain a plurality of spaced-apart second annular holes 1064. The region of the second conductive material layer 115 surrounding each second annular hole 1064 forms a second connection unit 1061. The second conductive material layer 115 located between adjacent second annular holes 1064 forms a second reflective region 1063.

[0140] An insulating material is deposited on the second conductive material layer 115, filling the second annular hole 1064. The insulating material on the top surface of the second conductive material layer 115 can be removed by chemical mechanical polishing (CMP), and the top surface of the insulating material filling the second annular hole 1064 is made flush with the top surface of the second conductive material layer 115 to form a plurality of second insulating units 1062, thereby obtaining the second bonding layer 106.

[0141] Furthermore, by providing the second insulating unit 1062 within the second bonding layer 106, the number of metal etching steps can be reduced during etching, thereby improving efficiency.

[0142] In one possible implementation, such as Figure 9 As shown, Figure 9 In the figure, d2 is used to indicate the thickness of the insulating material deposited on the top surface of the second conductive material layer 115. The thickness of the insulating material deposited on the top surface of the second conductive material layer 115 is 2 μm to 4 μm, so that the second annular hole 1064 is filled with insulating material, thereby improving the effect of hybrid bonding.

[0143] In one possible implementation, the material of the second conductive material layer 115 includes a gold-tin alloy.

[0144] Combination Figure 2 , Figure 15 and Figure 16 As shown, in some embodiments, the fabrication method further includes: forming a passivation layer 108, which covers the surfaces of a plurality of LED units 104 and the surfaces of bonding layers 103 exposed between adjacent LED units 104; forming a first opening 116 in the passivation layer 108, which exposes at least a portion of the top surface of the LED unit 104; forming a conductive layer 109, which covers the passivation layer 108 and is electrically connected to the LED unit 104 through the first opening 116; forming a second opening 117 in the conductive layer 109 and the passivation layer 108, which at least exposes a reflective region 1033; and forming a metal layer 107, which at least covers the second opening 117 and is connected to the reflective region 1033.

[0145] Specifically, an insulating material is deposited to form a passivation layer 108, which covers the surfaces of the plurality of LED cells 104 and the surfaces of the bonding layers 103 exposed between adjacent LED cells 104. The passivation layer 108 is etched to form a first opening 116, which exposes at least a portion of the top surface of the LED cells 104. ITO is deposited to form a transparent conductive layer 109, which covers the passivation layer 108 and is electrically connected to the LED cells 104 through the first opening 116.

[0146] The conductive layer 109 and the passivation layer 108 are etched to form a second opening 117, which exposes at least the reflective region 1033, and for example, may also expose part of the top surface of the insulating unit 1032.

[0147] A metallic material is deposited to form a metal layer 107, which at least covers the second opening 117 and is connected to the reflective region 1033. In actual fabrication, the metal layer 107 can be etched to surround the LED unit 104 to reduce the series resistance of the conductive layer 109 and further reduce or isolate optical crosstalk.

[0148] Combination Figure 19 As shown in the embodiments of this disclosure, a method for fabricating a miniature light-emitting diode display 100 is also provided, comprising the following steps:

[0149] Combination Figure 3 As shown, S1901 provides a substrate.

[0150] Combination Figure 4 As shown, in step S1902, a first conductive material layer is formed on the substrate.

[0151] Combination Figure 4 As shown, in S1903, the first conductive material layer is etched to form a plurality of first connection units arranged in an array, and each first connection unit is surrounded by a first annular hole, and the first conductive material layer located between adjacent first annular holes forms a first reflective region.

[0152] Combination Figure 5 As shown, in step S1904, an insulating material is deposited on the first conductive material layer, and the insulating material fills the first annular hole.

[0153] Combination Figure 6 As shown, in step S1905, the insulating material on the top surface of the first conductive material layer is removed to form a first insulating unit, thereby obtaining a first bonding layer.

[0154] Combination Figure 7 As shown in Figure S1906, a substrate is provided, on which an LED epitaxial layer structure, an electrode layer structure, and a reflector layer structure are sequentially stacked.

[0155] Combination Figure 7 As shown, S1907, a second conductive material layer is formed on the reflector layer structure.

[0156] Combination Figure 8 As shown, in step S1908, the second conductive material layer is etched to form a plurality of second connection units corresponding to a plurality of first connection units, a plurality of second annular holes corresponding to a plurality of first insulating units, and a second reflective region corresponding to a first reflective region.

[0157] Combination Figure 9 As shown, in step S1909, an insulating material is deposited on the second conductive material layer, and the insulating material fills the second annular hole.

[0158] Combination Figure 10 As shown, in step S1910, the insulating material on the top surface of the second conductive material layer is removed to form a second insulating unit, thereby obtaining a second bonding layer.

[0159] Combination Figure 11 As shown, in step S1911, the second bonding layer is bonded to the first bonding layer to form a bonding layer, wherein a plurality of second connecting units are bonded to a plurality of first connecting units in a one-to-one correspondence to form connecting units, a plurality of second insulating units are bonded to a plurality of first insulating units in a one-to-one correspondence to form insulating units, and a second reflective region is bonded to a first reflective region in a corresponding manner to form a reflective region.

[0160] Combination Figure 12 As shown, S1912, remove the substrate.

[0161] Combination Figure 13 As shown, S1913 etches the LED epitaxial layer structure, electrode layer structure and mirror layer structure to form the LED epitaxial layer, electrode layer and mirror layer respectively, so as to obtain multiple LED units, and the multiple LED units are disposed on multiple connection units one by one.

[0162] Combination Figure 15 As shown, in step S1914, a passivation layer is formed, which covers the surface of multiple LED units and the surface of the bonding layer exposed between adjacent LED units.

[0163] S1915, Etching the passivation layer forms a first opening, the first opening exposing at least a portion of the top surface of the LED unit.

[0164] S1916. A conductive layer is formed, which covers the passivation layer and is electrically connected to the LED unit through the first opening.

[0165] S1917, Etching the conductive layer and passivation layer to form a second opening, the second opening at least exposes the reflective area.

[0166] S1918. Form a metal layer that at least covers the second opening and is connected to the reflective area.

[0167] The fabrication of a miniature light-emitting diode display 100 was completed.

[0168] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. A miniature light-emitting diode display, characterized in that, include: substrate; A bonding layer is disposed on the substrate and includes multiple connection units, multiple insulating units, and a reflective region. The multiple connection units are arranged in an array on the substrate, and an insulating unit surrounds the outside of each connection unit. The reflective region is located between adjacent insulating units. Multiple LED units are respectively disposed on multiple connection units; The substrate is electrically connected to the corresponding LED unit through the connection unit, so that each LED unit can be driven individually. The bonding layer includes: A first bonding layer is disposed on the substrate and includes a plurality of first connecting units, a plurality of first insulating units, and a first reflective region. The plurality of first connecting units are arranged in an array on the substrate, and a first insulating unit surrounds the outside of each first connecting unit. The first reflective region is located between adjacent first insulating units. The second bonding layer is stacked and bonded on the first bonding layer, and includes a plurality of second connecting units corresponding to a plurality of first connecting units, a plurality of second insulating units corresponding to a plurality of first insulating units, and a second reflective region corresponding to the first reflective region. In this configuration, a plurality of second connecting units are bonded one-to-one with a plurality of first connecting units to form the connecting unit, a plurality of second insulating units are bonded one-to-one with a plurality of first insulating units to form the insulating unit, and a second reflective region is bonded to a corresponding first reflective region to form the reflective region.

2. The miniature light-emitting diode display according to claim 1, characterized in that, Also includes: A passivation layer covers the surfaces of the plurality of LED units and the surface of the bonding layer exposed between adjacent LED units, the passivation layer having a first opening that exposes at least a portion of the top surface of the LED unit; A conductive layer covers the passivation layer and is electrically connected to the LED unit through the first opening. The second opening penetrates the conductive layer and the passivation layer, and at least exposes the reflective area; A metal layer, at least covering the second opening and connected to the reflective area.

3. The miniature light-emitting diode display according to claim 2, characterized in that, The substrate includes a driving circuit having a plurality of first electrode contacts and at least one second electrode contact. The plurality of first electrode contacts are disposed in correspondence with and electrically connected to the plurality of connection units, and the second electrode contacts are electrically connected to the metal layer. The LED unit includes an LED epitaxial layer located above the connection unit, and the LED epitaxial layer includes a first semiconductor layer, a light-emitting layer, and a second semiconductor layer stacked together. The first electrode contact is electrically connected to the first semiconductor layer of the LED unit corresponding to the connection unit, and the second semiconductor layers of the plurality of LED units are connected to the second electrode contact through the conductive layer and the metal layer, so that each LED unit is driven individually.

4. The miniature light-emitting diode display according to claim 3, characterized in that, The LED unit further includes a reflector layer and an electrode layer, wherein the reflector layer, the electrode layer and the LED epitaxial layer are stacked sequentially, and the reflector layer is connected to the corresponding connection unit.

5. The miniature light-emitting diode display according to claim 1, characterized in that, The connecting unit is made of the same material as the reflective region, and the materials of the connecting unit and the reflective region include conductive materials; The material of the insulating unit includes insulating material.

6. A method for fabricating a miniature light-emitting diode display, characterized in that, Includes the following steps: Provide substrate; A bonding layer is disposed on the substrate, wherein the bonding layer includes a plurality of connecting units, a plurality of insulating units and a reflective region, the plurality of connecting units are arranged in an array on the substrate, each connecting unit surrounds an insulating unit, and the reflective region is located between adjacent insulating units; Multiple LED units are formed on the bonding layer, wherein each of the multiple LED units is disposed on a corresponding connection unit; The substrate is electrically connected to the corresponding LED unit through the connection unit, so that each LED unit can be driven individually. The step of forming a bonding layer on the substrate includes: A first bonding layer is formed on the substrate, wherein the first bonding layer includes a plurality of first connecting units, a plurality of first insulating units and a first reflective region, the plurality of first connecting units are arranged in an array on the substrate, each first connecting unit surrounds a first insulating unit, and the first reflective region is located between adjacent first insulating units. A substrate is provided on which an LED epitaxial layer structure is disposed; A second bonding layer is formed above the LED epitaxial layer structure, wherein the second bonding layer includes a plurality of second connection units corresponding to a plurality of first connection units, a plurality of second insulation units corresponding to a plurality of first insulation units, and a second reflection region corresponding to the first reflection region; The second bonding layer is bonded to the first bonding layer to form the bonding layer, wherein a plurality of second connecting units are bonded to a plurality of first connecting units in a one-to-one correspondence to form the connecting units, a plurality of second insulating units are bonded to a plurality of first insulating units in a one-to-one correspondence to form the insulating units, and a second reflective region is bonded to a corresponding first reflective region to form the reflective region.

7. The preparation method according to claim 6, characterized in that, The step of forming multiple LED units on the bonding layer includes: Remove the substrate; The LED epitaxial layer structure is etched to form multiple LED units, and the LED units are located above the corresponding connection units.

8. The preparation method according to claim 7, characterized in that, An electrode layer structure and a mirror layer structure are sequentially formed on the LED epitaxial layer structure, and the second bonding layer is formed on the surface of the mirror layer structure opposite to the electrode layer structure. The step of forming multiple LED units on the bonding layer further includes: The electrode layer structure is etched to form an electrode layer; The mirror layer structure is etched to form a mirror layer, and the mirror layer is connected to the corresponding connection unit.

9. The preparation method according to claim 6, characterized in that, The step of forming the first bonding layer on the substrate includes: A first conductive material layer is formed on the substrate; The first conductive material layer is etched to form a plurality of first connection units arranged in an array, and each first connection unit is surrounded by a first annular hole. The first conductive material layer located between adjacent first annular holes forms the first reflective region. The first insulating unit is formed in the first annular hole to obtain the first bonding layer; The step of forming a second bonding layer over the LED epitaxial layer structure includes: A second conductive material layer is formed above the LED epitaxial layer structure; The second conductive material layer is etched to form a plurality of second connection units corresponding to a plurality of first connection units, a plurality of second annular holes corresponding to a plurality of first insulating units, and a second reflective region corresponding to the first reflective region; The second insulating unit is formed in the second annular hole to obtain the second bonding layer.

10. The preparation method according to claim 8, characterized in that, Also includes: A passivation layer is formed, which covers the surfaces of the plurality of LED units and the surfaces of the bonding layer exposed between adjacent LED units; A first opening is formed in the passivation layer, the first opening exposing at least a portion of the top surface of the LED unit; A conductive layer is formed, which covers the passivation layer and is electrically connected to the LED unit through the first opening; A second opening is formed in the conductive layer and the passivation layer, the second opening exposing at least the reflective region; A metal layer is formed, which at least covers the second opening and is connected to the reflective area.

Images