Micro-LED display and method for manufacturing the same

Abstract

The present application relates to the technical field of semiconductor devices, and discloses a micro light-emitting diode display and a manufacturing method thereof. Among them, the micro light-emitting diode display includes a substrate, a first LED unit layer, and a second LED unit layer. The first LED unit layer is bonded to the substrate and includes a first passivation layer and a plurality of first LED units. The first passivation layer is located on the surface of the first LED unit layer facing away from the substrate and exposes the surfaces of the plurality of first LED units facing away from the substrate. And the first passivation layer further covers at least the sides of the plurality of first LED units. The second LED unit layer is bonded to the first LED unit layer and includes a plurality of second LED units and a filling layer located between adjacent second LED units. The filling layer is bonded to the first passivation layer. Among them, the plurality of first LED units and the plurality of second LED units are electrically connected to the substrate respectively. By using the passivation layer as a processing position reference, the present application also protects the LED units and realizes bonding, reduces the processing difficulty and cost, and improves the yield.

Description

Technical Field

[0001] This application belongs to the technical field of semiconductor devices, and particularly relates to a micro light-emitting diode display and a manufacturing method thereof. Background Art

[0002] The application scenarios of display technologies based on semiconductor devices are increasing, such as wearable devices, virtual reality (VR) / augmented reality (AR) devices, etc. However, the relatively large size of micro light-emitting diode displays limits the number of pixels that can be integrated on the display screens of small wearable devices such as AR glasses, affecting the resolution and display effect of the devices.

[0003] In related technologies, a microdisplay module and a manufacturing method thereof (CN119546027A) are disclosed. Specifically, the microdisplay module includes at least two stacked pixel layers bonded to the same side of a driving substrate. Specifically, the first pixel layer is bonded to the driving substrate through a first wiring layer, and the first pixel layer and the second pixel layer are bonded through a second wiring layer and a third wiring layer. The structure of the microdisplay module in related technologies is complex, resulting in a relatively large size of the microdisplay module and a high processing difficulty, leading to an increase in cost and a reduction in the overall yield. Summary of the Invention

[0004] This application aims to solve at least one of the technical problems existing in the related technologies.

[0005] Therefore, in the first aspect of this application, a micro light-emitting diode display is provided.

[0006] In the second aspect of this application, a manufacturing method of a micro light-emitting diode display is provided.

[0007] According to the first aspect of the embodiments of this application, a micro light-emitting diode display is proposed, including: a substrate; a first LED unit layer bonded to the substrate, including a first passivation layer and a plurality of first LED units arranged at intervals; the first passivation layer is located on the surface of the first LED unit layer facing away from the substrate side and exposes the surfaces of the plurality of first LED units facing away from the substrate side; and the first passivation layer also covers at least the sides of the plurality of first LED units; a second LED unit layer bonded to the first LED unit layer, including a plurality of second LED units arranged at intervals and a filling layer located between adjacent second LED units, and the filling layer is bonded to the first passivation layer; wherein, the plurality of first LED units and the plurality of second LED units are respectively electrically connected to the substrate to achieve independent driving.

[0008] In a possible implementation of the first aspect, the substrate includes a plurality of first contacts, and the first LED unit layer further includes: a planarization layer disposed on a side of the first passivation layer facing the substrate and bonded to the substrate; and a first conductive bump, one end of the first conductive bump is electrically connected to the first LED unit, and the other end is bonded and electrically connected to the corresponding first contact.

[0009] In a possible implementation of the first aspect, the first LED unit layer further includes: a first electrode layer disposed on a side of the first passivation layer facing away from the first LED unit and surrounding the side surface and the side surface facing the substrate of the first LED unit; and the first electrode layer covers the surface of the area of the first LED unit facing the substrate side and not covered by the first passivation layer, and the first electrode layer reflects the light emitted by the first LED unit.

[0010] In a possible implementation of the first aspect, the second LED unit layer further includes: a second passivation layer disposed on a surface of the filling layer facing away from the substrate side and exposing the surfaces of a plurality of the second LED units facing away from the substrate side; and the second passivation layer further covers at least the side surfaces of a plurality of the second LED units.

[0011] In a possible implementation of the first aspect, the second LED unit layer further includes: a second electrode layer disposed on a side of the second passivation layer facing away from the second LED unit and surrounding the side surface and the side surface facing the substrate of the second LED unit; and the second electrode layer covers the surface of the position of the second LED unit facing the substrate side and not covered by the second passivation layer, and the second electrode layer reflects the light emitted by the second LED unit.

[0012] In a possible implementation of the first aspect, the micro light-emitting diode display further includes: a conductive column vertically penetrating the first LED unit layer, one end of the conductive column is electrically connected to the substrate, and the other end of the conductive column is electrically connected to the corresponding second LED unit.

[0013] In a possible implementation of the first aspect, the second LED unit layer further includes: a second conductive bump electrically connected to the second LED unit; wherein, the conductive column is electrically connected to the second LED unit through the second conductive bump.

[0014] In a possible implementation of the first aspect, the surface area of the side of the second conductive bump bonded to the conductive column is larger than the surface area of the side connected to the second electrode layer.

[0015] In a possible implementation of the first aspect, the first LED unit and the second LED unit each include a first doped semiconductor layer, an active layer, and a second doped semiconductor layer that are stacked, and the first doped semiconductor layer is close to the substrate; the surface of the second doped semiconductor layer of the first LED unit on the side facing away from the substrate is flush with the surface of the first passivation layer on the side facing away from the substrate; the surface of the second doped semiconductor layer of the second LED unit on the side facing away from the substrate is flush with the surface of the second passivation layer on the side facing away from the substrate.

[0016] In a possible implementation of the first aspect, the substrate includes at least one second contact, and the micro light-emitting diode display further includes: a common electrode layer, electrically connected to the surfaces of the first LED unit and the second LED unit on the side facing away from the substrate, and the common electrode layer is electrically connected to the second contact.

[0017] In a possible implementation of the first aspect, the micro light-emitting diode display further includes: a plurality of color conversion units, arranged at intervals on the side of the second LED unit layer facing away from the substrate and located on some of the first LED units or some of the second LED units, and the color conversion units are configured to convert the first color light emitted by the first LED unit or the second color light emitted by the second LED unit into a third color light, and the first color light, the second color light, and the third color light are different; wherein, at least one first LED unit, at least one adjacent second LED unit, and at least one adjacent color conversion unit form a full-color pixel.

[0018] In a possible implementation of the first aspect, the micro light-emitting diode display further includes: a third LED unit layer, bonded to the second LED unit layer, including a plurality of third LED units arranged at intervals, and the vertical projections of the first LED unit, the second LED unit, and the third LED unit on the substrate do not overlap; wherein, at least one first LED unit, at least one adjacent second LED unit, and at least one adjacent third LED unit form a full-color pixel.

[0019] According to a second aspect of the embodiments of the present application, a method for manufacturing a micro light-emitting diode display is provided, including the following steps:

[0020] Provide a substrate;

[0021] Prepare a first LED unit layer, the first LED unit layer including a first passivation layer and a plurality of first LED units arranged at intervals; the first passivation layer is located on the surface of the first LED unit layer facing away from the substrate side and exposes the surfaces of the plurality of first LED units facing away from the substrate side; and the first passivation layer also covers at least the sides of the plurality of first LED units;

[0022] Bond the first LED unit layer to the substrate;

[0023] Prepare a second LED unit layer, the second LED unit layer including a plurality of second LED units arranged at intervals and a filling layer located between adjacent second LED units;

[0024] Bond the second LED unit layer to the first LED unit layer, wherein the filling layer is bonded to the first passivation layer;

[0025] Wherein, the plurality of first LED units and the plurality of second LED units are respectively electrically connected to the substrate to achieve individual driving.

[0026] In a possible implementation manner of the second aspect, the steps of preparing the first LED unit layer include:

[0027] Provide a first substrate, with a first LED epitaxial layer disposed on the first substrate;

[0028] Etch the first LED epitaxial layer (on the side facing away from the first substrate) to form a plurality of first LED units;

[0029] Form a first passivation layer, the first passivation layer covering the surface of the etched first LED epitaxial layer and exposing partial surfaces of the plurality of first LED units facing away from the first substrate side.

[0030] In a possible implementation manner of the second aspect, the steps of preparing the first LED unit layer further include:

[0031] Form a first electrode layer on the side of the first passivation layer facing away from the first LED unit, the first electrode layer surrounding the sides and the side facing away from the first substrate of the first LED unit, and the first electrode layer also covering the surface of the region of the first LED unit facing away from the first substrate side and not covered by the first passivation layer;

[0032] Form a planarization layer, the planarization layer covering the first passivation layer and the first electrode layer;

[0033] A first conductive protrusion and a conductive column are formed, wherein one end of the first conductive protrusion is connected to the first electrode layer, and the other end vertically extends to the surface of the planarization layer away from the first substrate side; the conductive column vertically penetrates the planarization layer and the first passivation layer.

[0034] In a possible implementation manner of the second aspect, the step of bonding the first LED unit layer to the substrate includes:

[0035] Bonding the planarization layer to the substrate, and bonding and electrically connecting the first conductive protrusions and the conductive pillars to the corresponding first contacts;

[0036] The first substrate and a portion of the first LED epitaxial layer are removed until the surface of the first passivation layer is exposed, so that the first passivation layer, the first LED unit, and the surface of the conductive column facing away from the substrate are flush.

[0037] In a possible implementation manner of the second aspect, the step of preparing the second LED unit layer includes:

[0038] Providing a second substrate, on which a second LED epitaxial layer is disposed;

[0039] Etching the second LED epitaxial layer (the side facing away from the second substrate) to form a plurality of second LED units;

[0040] forming a second passivation layer, wherein the second passivation layer covers the surface of the etched second LED epitaxial layer and exposes a portion of the surface of a plurality of second LED units away from the second substrate;

[0041] A second electrode layer is formed on a side of the second passivation layer away from the second LED unit, the second electrode layer is arranged around a side of the second LED unit and a side away from the second substrate, and the second electrode layer covers a surface of the second LED unit away from the second substrate and not covered by the second passivation layer;

[0042] forming a filling layer, wherein the filling layer covers the second passivation layer and the second electrode layer;

[0043] A second conductive protrusion is formed on the leveling layer, one end of the second conductive protrusion is electrically connected to the second electrode layer, and the other end of the second conductive protrusion vertically extends to a surface of the leveling layer away from the second substrate.

[0044] In a possible implementation manner of the second aspect, the micro light emitting diode display further includes a conductive column, and the step of bonding the second LED unit layer to the first LED unit layer includes:

[0045] Bond the leveling layer to the first passivation layer, and bond and electrically connect the second conductive bump to the end of the conductive column facing away from the substrate;

[0046] Remove the second substrate and part of the second LED epitaxial layer until the surface of the second passivation layer is exposed, so that the surface of the second passivation layer is flush with the surface of the second LED unit on the side facing away from the substrate.

[0047] In a possible implementation manner of the second aspect, after the step of bonding the second LED unit layer to the first LED unit layer, the manufacturing method further includes:

[0048] Etch the second LED unit layer to expose the surface of the first LED unit on the side facing away from the substrate;

[0049] Form a common electrode layer that at least covers the surfaces of the first LED unit and the second LED unit on the side facing away from the substrate, and the common electrode layer is electrically connected to the second contact of the substrate.

[0050] In a possible implementation manner of the second aspect, the manufacturing method further includes:

[0051] Form a protective layer that at least covers the common electrode layer;

[0052] Form a color conversion unit in the protective layer, and the color conversion unit is located above part of the first LED unit or part of the second LED unit.

[0053] The micro light-emitting diode display and its manufacturing method provided by the present application can at least achieve the following technical effects:

[0054] By having the first passivation layer on the surface of the first LED unit layer facing away from the substrate and exposing the surfaces of multiple first LED units facing away from the substrate, when processing the first LED unit layer, the first passivation layer can be used as a processing position reference, reducing the processing difficulty and cost, and reducing the situation of device damage caused by overprocessing, so as to protect the first LED unit during the processing and improve the overall yield. By having the first passivation layer at least cover the sides of multiple first LED units, the first LED units are protected, and leakage is avoided or reduced, improving the stability and reliability of the display. By bonding the leveling layer to the first passivation layer, the first LED unit layer and the second LED unit layer are bonded and connected, further reducing the processing difficulty and cost, improving the overall yield, and reducing the thickness of the display in the vertical direction, thereby reducing the size of the display.

[0055] The above general description and the following description are only exemplary and explanatory, and are not used to limit the present application. Brief Description of the Drawings

[0056] One or more embodiments are exemplarily illustrated by corresponding drawings. These exemplary illustrations and the drawings do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements. The drawings do not constitute a scale limitation, and among them:

[0057] Figure 1 Schematic structural diagram of a display provided by an embodiment of the present disclosure;

[0058] Figure 2 Schematic structure of the structure in the process of preparing the first LED unit layer provided by an embodiment of the present disclosure Figure 1 ;

[0059] Figure 3 Schematic structure of the structure in the process of preparing the first LED unit layer provided by an embodiment of the present disclosure Figure 2 ;

[0060] Figure 4 Schematic structure of the structure in the process of preparing the first LED unit layer provided by an embodiment of the present disclosure Figure 3 ;

[0061] Figure 5 Schematic structure of the structure in the process of preparing the first LED unit layer provided by an embodiment of the present disclosure Figure 4 ;

[0062] Figure 6 Schematic structure of the structure in the process of preparing the first LED unit layer provided by an embodiment of the present disclosure Figure 5 ;

[0063] Figure 7 Schematic structure of the structure in the process of preparing the first LED unit layer provided by an embodiment of the present disclosure Figure 6 ;

[0064] Figure 8 Schematic structure of the structure in the process of preparing the first LED unit layer provided by an embodiment of the present disclosure Figure 7 ;

[0065] Figure 9 Schematic structure of the structure in the process of preparing the first LED unit layer provided by an embodiment of the present disclosure Figure 8 ;

[0066] Figure 10 Schematic structure of the structure in the process of preparing the second LED unit layer provided by an embodiment of the present disclosure Figure 1 ;

[0067] Figure 11Schematic structure of the structure in the process of preparing the second LED unit layer provided by the present disclosure Figure 2 ;

[0068] Figure 12 Schematic structure of the structure in the process of preparing the second LED unit layer provided by the present disclosure Figure 3 ;

[0069] Figure 13 Schematic structure of the structure in the process of preparing the second LED unit layer provided by the present disclosure Figure 4 ;

[0070] Figure 14 Schematic structure of the structure in the process of preparing the second LED unit layer provided by the present disclosure Figure 5 ;

[0071] Figure 15 Schematic structure of the structure in the process of preparing the second LED unit layer provided by the present disclosure Figure 6 ;

[0072] Figure 16 Schematic structure of the structure in the process of preparing the second LED unit layer provided by the present disclosure Figure 7 ;

[0073] Figure 17 Schematic structure of the structure in the process of preparing the second LED unit layer provided by the present disclosure Figure 8 ;

[0074] Figure 18 Schematic structure of the structure in the process of bonding the first LED unit layer to the substrate provided by the present disclosure Figure 1 ;

[0075] Figure 19 Schematic structure of the structure in the process of bonding the first LED unit layer to the substrate provided by the present disclosure Figure 2 ;

[0076] Figure 20 Schematic structure of the structure in the process of bonding the second LED unit layer to the first LED unit layer provided by the present disclosure Figure 1 ;

[0077] Figure 21 Schematic structure of the structure in the process of bonding the second LED unit layer to the first LED unit layer provided by the present disclosure Figure 2 ;

[0078] Figure 22 For Figure 21 Schematic structural diagram of forming a common electrode layer on the structure provided by the embodiment shown;

[0079] Figure 23 Schematic structural diagram for forming a protective layer on the structure provided in the Figure 22 illustrated embodiment;

[0080] Figure 24 Schematic structural diagram for etching a window in the protective layer;

[0081] Figure 25 Schematic structural diagram of a display provided in another embodiment of the present disclosure;

[0082] Figure 26 Flowchart of a method for manufacturing a display provided in an embodiment of the present disclosure;

[0083] Figure 27 Flowchart of a method for manufacturing a first LED unit layer provided in an embodiment of the present disclosure;

[0084] Figure 28 Flowchart of a method for manufacturing a second LED unit layer provided in an embodiment of the present disclosure;

[0085] Figure 29 Flowchart of a method for manufacturing a display provided in another embodiment of the present disclosure;

[0086] Figure 30 Flowchart of a method for manufacturing a display provided in still another embodiment of the present disclosure.

[0087] The reference numerals are denoted as:

[0088] 1: Display;

[0089] 10: Substrate; 11: First contact;

[0090] 20: First LED unit layer; 21: First passivation layer; 22: First LED unit; 23: Planarization layer; 24: First conductive bump; 25: First electrode layer; 26: Conductive column; 261: First end; 262: Second end; 27: First substrate; 28: First LED epitaxial layer;

[0091] 30: Second LED unit layer; 31: Second LED unit; 32: Filling layer; 33: Second passivation layer; 34: Second electrode layer; 35: Second conductive bump; 36: Second substrate; 37: Second LED epitaxial layer;

[0092] 40: Common electrode layer; 41: Protective layer; 42: Color conversion unit;

[0093] 50: The third LED unit layer; 51: The third LED unit; 52: The third passivation layer; 53: The filling layer; 54: The third electrode; 55: The conductive connection post; 56: The third conductive protrusion. Detailed implementation manners

[0094] In order to be able to understand the features and technical content of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are only for reference and explanation purposes and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a sufficient understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, well-known structures and devices can be shown in a simplified manner.

[0095] The terms "first", "second", etc. in the description and claims of the embodiments of the present disclosure and the above accompanying drawings are used to distinguish similar objects and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so as to implement the embodiments of the present disclosure described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion.

[0096] In the embodiments of the present disclosure, the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "middle", "outer", "front", "rear", etc. is based on the orientation or positional relationship shown in the accompanying drawings. These terms are mainly used to better describe the embodiments of the present disclosure and their embodiments and are not used to limit that the indicated devices, elements or components must have a specific orientation or be constructed and operated in a specific orientation. And, in addition to being able to represent an orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0097] In addition, the terms "arranged", "connected", "fixed" should be understood in a broad sense. For example, "connected" 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 directly connected, or indirectly connected through an intermediate medium, or there is an internal connection between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0098] Unless otherwise specified, the term "plurality" means two or more.

[0099] In the embodiments of the present disclosure, the character " / " indicates an "or" relationship between the preceding and following objects. For example, A / B means: A or B.

[0100] The term "and / or" is an associative relationship describing objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, the three relationships of A and B.

[0101] It should be noted that, without conflict, the embodiments in the embodiments of the present disclosure and the features in the embodiments can be combined with each other.

[0102] It should be noted that the term "layer" used in the embodiments of the present disclosure refers to a portion of a material including a region having a certain thickness. The layer can extend over the entire underlying or overlying structure, or can have an extent less than the extent of the underlying or overlying structure. In addition, the layer can be a region of a homogeneous or heterogeneous continuous structure, the thickness of which is less than the thickness of the continuous structure. For example, the layer can be located between the top and bottom surfaces of the continuous structure or between any pair of horizontal planes therebetween. The layer can extend horizontally, vertically, and / or along a tapered surface.

[0103] It should be noted that the term "micro" used in the embodiments of the present disclosure refers to the descriptive size of certain devices or structures according to the embodiments of the present application. The term "micro" device or structure used herein is intended to represent a scale of 0.1 to 100 μm. However, it should be understood that the embodiments of the present application are not necessarily limited thereto, and certain aspects of the embodiments can be applied to larger and possibly smaller size scales.

[0104] For the sake of simplicity of description, in the following description, part of the "micro light-emitting diode display" is simplified to be described as "display".

[0105] According to a first aspect of the embodiments of the present application, in combination with Figures 1 to 25As shown, a micro light-emitting diode display 1 is provided, including a substrate 10, a first LED unit layer 20, and a second LED unit layer 30. The first LED unit layer 20 is bonded to the substrate 10. The second LED unit layer 30 includes a first passivation layer 21 and a plurality of first LED units 22 arranged at intervals. The first passivation layer 21 is located on the surface of the first LED unit layer 20 facing away from the substrate 10, and exposes the surfaces of the plurality of first LED units 22 facing away from the substrate 10. And the first passivation layer 21 further covers at least the sides of the plurality of first LED units 22. The second LED unit layer 30 is bonded to the first LED unit layer 20. The second LED unit layer 30 includes a plurality of second LED units 31 arranged at intervals and a planarizing layer 32 located between adjacent second LED units 31. The planarizing layer 32 is bonded to the first passivation layer 21. Among them, the plurality of first LED units 22 and the plurality of second LED units 31 are respectively electrically connected to the substrate 10 to achieve independent driving.

[0106] Since the first passivation layer 21 is located on the surface of the first LED unit layer 20 facing away from the substrate 10, the first passivation layer 21 exposes the surfaces of the plurality of first LED units 22 facing away from the substrate 10. When fabricating the micro light-emitting diode display 1, the first passivation layer 21 can be used as a processing position reference, reducing the processing difficulty and cost, and avoiding or reducing the damage of the device caused by overprocessing, so as to protect the first LED units 22 during the processing and improve the overall yield.

[0107] Exemplarily, after the first LED unit layer 20 is bonded to the substrate 10, a part of the first LED epitaxial layer 28 can be removed by chemical mechanical polishing (CMP). During the CMP process, the first passivation layer 21 serves as a processing position reference, that is, the CMP process stops when the first passivation layer 21 is exposed, reducing the processing difficulty and cost. Moreover, by providing a clear reference position by the first passivation layer 21, the situation of device damage caused by overprocessing is avoided or reduced, so as to effectively protect the first LED units 22 during the processing and improve the overall yield.

[0108] Since the first passivation layer 21 is located on the surface of the first LED unit layer 20 facing away from the substrate 10, the planarizing layer 32 can be smoothly bonded to the first passivation layer 21. By bonding the planarizing layer 32 to the first passivation layer 21, the bonding connection between the first LED unit layer 20 and the second LED unit layer 30 is realized, further reducing the processing difficulty and cost, improving the overall yield, and reducing the thickness of the display 1 in the vertical direction, thereby reducing the size of the display 1.

[0109] The first passivation layer 21 covers at least the sides of a plurality of first LED units 22. For example, the first passivation layer 21 may cover the sides of a plurality of first LED units 22 and a portion of the surface of a plurality of first LED units 22 facing the substrate 10 side. By covering at least the sides of a plurality of first LED units 22 with the first passivation layer 21, the first LED units 22 are protected. Moreover, when the first LED units 22 are connected to electrodes, the first passivation layer 21 can also avoid or reduce leakage, improving the stability and reliability of the display 1.

[0110] The micro light-emitting diode display 1 includes a substrate 10, a first LED unit layer 20, and a second LED unit layer 30. The first LED unit layer 20 is bonded to the substrate 10, and the second LED unit layer 30 is bonded to the first LED unit layer 20, reducing the thickness of the display 1 in the vertical direction, achieving a reduction in the size of the display 1, and having a simple processing process, low cost, and good economy.

[0111] By electrically connecting a plurality of first LED units 22 and a plurality of second LED units 31 to the substrate 10 respectively, each first LED unit 22 can be individually driven by the substrate 10, and each second LED unit 31 can be individually driven by the substrate 10.

[0112] It should be noted that the vertical direction can be understood as the direction perpendicular or approximately perpendicular to the upper surface of the substrate 10, that is, Figure 1 and Figure 25 the direction from top to bottom in

[0113] In this embodiment, the substrate 10 refers to the material on which subsequent material layers are added. The substrate 10 itself can be patterned. The material added to the top of the substrate 10 can be patterned or can remain unpatterned. In addition, the substrate 10 can include various semiconductor materials, such as silicon, silicon carbide, gallium nitride, germanium, gallium arsenide, indium phosphide. Alternatively, the substrate 10 can be made of non-conductive materials, such as glass, plastic, or sapphire wafers. Further alternatively, the substrate 10 can have semiconductor devices or circuits formed therein.

[0114] In addition, the substrate 10 can be provided with a circuit layer including complementary metal oxide semiconductor (CMOS) devices or thin film transistor (TFT) devices, etc. These CMOS devices or TFT devices can constitute a driving circuit.

[0115] In a possible implementation, in combination with Figure 1 and Figure 25As shown, along the vertical direction, the projections of the first LED unit 22 and the second LED unit 31 on the substrate 10 do not overlap. The first LED unit 22 is used to emit first-color light, and the second LED unit 31 is used to emit second-color light, and the first-color light is different from the second-color light.

[0116] By the non-overlapping of the vertical projections of the first LED unit 22 and the second LED unit 31 on the substrate 10, the brightness and color distribution of the displayed color are made more uniform, improving the user's visual experience.

[0117] The first-color light is different from the second-color light to achieve a colorful display. For example, the first-color light is blue light and the second-color light is green light. The first-color light is blue light and the second-color light is red light. Also, for example, the first-color light is green light and the second-color light is blue light. Also, for example, the first-color light is green light and the second-color light is red light. Also, for example, the first-color light is red light and the second-color light is green light. Also, for example, the first-color light is red light and the second-color light is blue light.

[0118] In a possible implementation, the material of the first passivation layer 21 includes aluminum oxide ( ), or silicon dioxide ( ).

[0119] In a possible implementation, the material of the planarization layer 32 includes silicon dioxide ( ), silicon nitride, or benzocyclobutene (BCB).

[0120] It can be understood that the shapes of the first LED unit 22 and the second LED unit 31 are not limited. For example, they can be frustum-conical or cubic in shape, etc.

[0121] In some embodiments, as shown in combination with Figure 1 and Figure 25 , the substrate 10 includes a plurality of first contacts 11. The first LED unit layer 20 further includes a planarization layer 23 and a first conductive bump 24. The planarization layer 23 is disposed on the side of the first passivation layer 21 facing the substrate 10, and the planarization layer 23 is bonded to the substrate 10. The first conductive bump 24 is disposed on the planarization layer 23. One end of the first conductive bump 24 is electrically connected to the first LED unit 22, and the other end is bonded and electrically connected to the corresponding first contact 11.

[0122] The planarization layer 23 is disposed on the side of the first passivation layer 21 facing the substrate 10, which can enable the smooth bonding of the planarization layer 23 and the substrate 10, reducing the processing difficulty and cost. And it can reduce the overall thickness of the display 1 in the vertical direction, realizing the reduction of the size of the display 1.

[0123] The first conductive bump 24 is disposed on the planarization layer 23. Specifically, the first conductive bump 24 is disposed on the side of the first LED unit layer 20 facing the substrate 10. One end of the first conductive bump 24 is electrically connected to the first LED unit 22 smoothly, and the other end of the first conductive bump 24 is bonded and electrically connected to the corresponding first contact 11 smoothly. Thus, the first contact 11 on the substrate 10 can apply a voltage to the first LED unit 22 individually, and the first LED unit 22 can be driven individually.

[0124] It should be noted that the bonding of the first conductive bump 24 to the corresponding first contact 11 means that each first contact 11 is electrically connected to only one first LED unit 22 or the second LED unit layer 30. Therefore, each first conductive bump 24 is used to connect a first LED unit 22 and the corresponding first contact 11.

[0125] In a possible implementation, the material of the planarization layer 23 includes silicon dioxide ( ), silicon nitride or benzocyclobutene (BCB).

[0126] In a possible implementation, the material of the first conductive bump 24 includes copper (Cu).

[0127] In a possible implementation, combining Figure 1 and Figures 18 to 25 as shown, the surface area of the bonding side of the first conductive bump 24 and the first contact 11 is larger than the surface area of the connection side with the first LED unit 22.

[0128] Combining Figure 1 , Figure 18 and Figure 19 as shown, A is used to indicate the bonding side of the first conductive bump 24 and the first contact 11, and B is used to indicate the connection side of the first conductive bump 24 and the first LED unit 22. By making the surface area of the lower end of the first conductive bump 24 larger than the surface area of the upper end, the size of the display 1 can be reduced to a certain extent, and the bonding accuracy of the first conductive bump 24 and the first contact 11 can be improved, so as to integrate more first LED units 22 on the same display area, increase the pixel density, and thus improve the resolution and display effect of the device.

[0129] In a possible implementation, the display 1 further includes a first connection layer, which is disposed between the first LED unit layer 20 and the substrate 10. The first connection layer has a plurality of solder pads arranged at intervals. In the vertical direction, the solder pad runs through the first connection layer. One side of the first connection layer is bonded to the substrate 10, and the other side is bonded to the planarization layer 23 of the first LED unit layer 20. One end of the solder pad is bonded and electrically connected to the first contact 11 of the substrate 10, and the other end of the solder pad is bonded and electrically connected to the first conductive protrusion 24, so as to achieve bonding of the first LED unit layer 20 to the substrate 10.

[0130] It should be noted that the material of the first connection layer is not limited, for example, silicon dioxide. The material of the solder pad is not limited, for example, copper.

[0131] In some embodiments, in combination Figure 1 , Figures 5 to 9 as well as Figures 18 to 25 As shown, the first LED unit layer 20 further includes a first electrode layer 25. The first electrode layer 25 is disposed on a side of the first passivation layer 21 away from the first LED unit 22, and is disposed around the side of the first LED unit 22 and the side facing the substrate 10. In addition, the first electrode layer 25 covers the surface of the first LED unit 22 facing the substrate 10 and not covered by the first passivation layer 21. The first electrode layer 25 reflects the light emitted by the first LED unit 22.

[0132] The first electrode layer 25 is disposed around the side of the first LED unit 22 and the side facing the substrate 10. Figure 1 As shown, the first electrode layer 25 is arranged around the side and bottom of the first LED unit 22 to form a reflective cup on the side and bottom of the first LED unit 22, so that the first electrode layer 25 can reflect the light emitted by the first LED unit 22, improve the light extraction efficiency, and prevent or reduce optical crosstalk. The reflective cup can also reduce the light hitting the adjacent first LED unit 22, further improving the light extraction efficiency. In addition, the reflective cup can make the light spot more concentrated and the pixel points more compact. While reducing the size of the display 1, more first LED units 22 can be integrated on the same display area, thereby improving the pixel density, and improving the resolution and display effect of the device.

[0133] The first electrode layer 25 covers the surface of the first LED unit 22 facing the substrate 10 and not covered by the first passivation layer 21, so that the first electrode layer 25 is electrically connected to the first LED unit 22. Figure 1 As shown, the first electrode layer 25 is electrically connected to the bottom of the first LED unit 22 .

[0134] The first electrode layer 25 is disposed on the side of the first passivation layer 21 away from the first LED unit 22. That is to say, among the side surface and the bottom surface of the first LED unit 22, except for the position where the first electrode layer 25 is electrically connected to the first LED unit 22, the first passivation layer 21 is provided between the first electrode layer 25 and the first LED unit 22 at other positions. The first LED unit 22 is protected through the first passivation layer 21, and the leakage can also be prevented or reduced, improving the stability and reliability of the display 1.

[0135] It should be noted that the material of the first electrode layer 25 is not limited. For example, it can be aluminum, silver, etc.

[0136] In a possible implementation manner, in combination with Figure 1 and Figures 18 to 25 as shown, the side of the first electrode layer 25 away from the first LED unit 22 is electrically connected to one end of the first conductive bump 24 away from the first contact 11. That is, the first contact 11 is electrically connected to the first LED unit 22 through the first conductive bump 24 and the first electrode layer 25 to apply a voltage to the first LED unit 22 individually.

[0137] In some embodiments, in combination with Figure 1 、 Figures 12 to 17 and Figures 20 to 25 as shown, the second LED unit layer 30 further includes a second passivation layer 33. The second passivation layer 33 is disposed on the surface of the planarization layer 32 away from the substrate 10 side, and exposes the surfaces of a plurality of second LED units 31 away from the substrate 10 side. And the second passivation layer 33 at least covers the side surfaces of a plurality of second LED units 31.

[0138] By disposing the second passivation layer 33 on the surface of the planarization layer 32 away from the substrate 10 side and exposing the surfaces of a plurality of second LED units 31 away from the substrate 10 side, when manufacturing the micro light-emitting diode display 1, the second passivation layer 33 can be used as a processing position reference, reducing the processing difficulty and cost of the processing technology, and avoiding or reducing the situation of device damage caused by over-processing, so as to protect the second LED units 31 during the processing and improve the overall yield.

[0139] In a specific example, when manufacturing the micro light-emitting diode display 1, first bond the first LED unit layer 20 to the substrate 10, and then bond the second LED unit layer 30 to the first LED unit layer 20. After the second LED unit layer 30 is bonded to the first LED unit layer 20, part of the first LED epitaxial layer 28 can be removed by chemical mechanical polishing (CMP). Stop the CMP process when the first passivation layer 21 is exposed to avoid or reduce over-processing, effectively protect the first LED unit 22, and reduce the processing difficulty and cost. This provides a connection surface for bonding the second LED unit layer 30 to the first LED unit layer 20 and enables the first LED unit 22 to emit light effectively. After the second LED unit layer 30 is bonded to the first LED unit layer 20, part of the second LED epitaxial layer 37 can be removed by CMP. Stop the CMP process when the second passivation layer 33 is exposed to avoid or reduce over-processing, effectively protect the second LED unit 31, and reduce the processing difficulty and cost. Through the cooperation of the first passivation layer 21 and the second passivation layer 33, as the processing position reference for different processing steps, the overall processing difficulty is reduced and the yield is improved.

[0140] In another specific example, when the display 1 further includes a third LED unit layer 50, by disposing the second passivation layer 33 on the surface of the planarization layer 32 facing away from the substrate 10, smooth bonding between the second passivation layer 33 and the third LED unit layer 50 can be achieved, reducing the processing difficulty and cost and improving the overall yield. And in the vertical direction, the thickness of the display 1 is reduced, thereby reducing the size of the display 1.

[0141] The second passivation layer 33 covers at least the sides of a plurality of second LED units 31. For example, the second passivation layer 33 can cover the sides of a plurality of second LED units 31 and a part of the surface of a plurality of second LED units 31 facing the substrate 10 side. By covering at least the sides of a plurality of second LED units 31 with the second passivation layer 33, protection of the second LED units 31 is achieved. And when the second LED units 31 are connected to electrodes, the second passivation layer 33 can also avoid or reduce leakage, improving the stability and reliability of the display 1.

[0142] In a possible implementation manner, the material of the second passivation layer 33 includes aluminum oxide ( ), or silicon dioxide ( ).

[0143] In some embodiments, in combination with Figure 1 , Figures 13 to 17 and Figures 20 to 25As shown, the second LED unit layer 30 further includes a second electrode layer 34. The second electrode layer 34 is disposed on the side of the second passivation layer 33 away from the second LED unit 31, and surrounds the side surface and the side facing the substrate 10 of the second LED unit 31. Moreover, the second electrode layer 34 covers the surface of the position on the side of the second LED unit 31 facing the substrate 10 that is not covered by the second passivation layer 33. The second electrode layer 34 reflects the light emitted by the second LED unit 31.

[0144] The second electrode layer 34 surrounds the side surface and the side facing the substrate 10 of the second LED unit 31. Combining Figure 1 As shown, the second electrode layer 34 surrounds the side surface and the bottom surface of the second LED unit 31 to form a reflective cup on the side surface and the bottom surface of the second LED unit 31, enabling the second electrode layer 34 to reflect the light emitted by the second LED unit 31, improving the light extraction efficiency, and preventing or reducing optical crosstalk. The reflective cup can also reduce the light hitting the adjacent second LED units 31, further improving the light extraction efficiency. Moreover, the reflective cup can make the light spot more concentrated, make the pixel points more compact, and while reducing the size of the display 1, more second LED units 31 can be integrated on the same display area, improving the pixel density, resolution, and display effect of the device.

[0145] The second electrode layer 34 covers the surface of the position on the side of the second LED unit 31 facing the substrate 10 that is not covered by the second passivation layer 33, realizing the electrical connection between the second electrode layer 34 and the second LED unit 31. Combining Figure 1 As shown, the second electrode layer 34 is electrically connected to the bottom position of the second LED unit 31.

[0146] The second electrode layer 34 is disposed on the side of the second passivation layer 33 away from the second LED unit 31. That is to say, among the side surface and the bottom surface of the first LED unit 22, except for the position where the second electrode layer 34 is electrically connected to the second LED unit 31, the second passivation layer 33 is provided between the second electrode layer 34 and the second LED unit 31 at other positions. The second passivation layer 33 is used to protect the second LED unit 31 and can also prevent or reduce the leakage current, improving the stability and reliability of the display 1.

[0147] It should be noted that the material of the second electrode layer 34 is not limited. For example, it can be aluminum, silver, etc.

[0148] In some embodiments, combining Figure 1 、 Figure 9 、 Figures 18 to 25As shown, the micro light-emitting diode display 1 further includes a conductive post 26. The conductive post 26 vertically penetrates the first LED unit layer 20. One end of the conductive post 26 is electrically connected to the substrate 10, and the other end of the conductive post 26 is electrically connected to the corresponding second LED unit 30. Specifically, the conductive post 26 includes a first end 261 and a second end 262, and the first end 261 of the conductive post 26 is bonded to the first contact 11 of the corresponding substrate 10. The second LED unit layer 30 further includes a second conductive protrusion 35 disposed on the planarization layer 32. The second conductive protrusion 35 is electrically connected to the second LED unit 30. Among them, the conductive post 26 is electrically connected to the second LED unit 30 through the second conductive protrusion 35. Specifically, one end of the second conductive protrusion 35 is electrically connected to the second electrode layer 34, and the other end of the second conductive protrusion 35 is bonded and electrically connected to the second end 262 of the conductive post 26.

[0149] The conductive post 26 vertically penetrates the first LED unit layer 20. In combination with Figure 1 As shown, the conductive post 26 penetrates the first LED unit layer 20 in the direction from top to bottom, so that the first end 261 of the conductive post 26 is successfully bonded and electrically connected to the first contact 11 directly below it, and the second end 262 of the conductive post 26 is successfully bonded and electrically connected to the second conductive protrusion 35 directly above it. Moreover, one end of the second conductive protrusion 35 facing away from the conductive post 26 is electrically connected to the second electrode layer 34, and the second electrode layer 34 is electrically connected to the second LED unit 31, realizing that the first contact 11 of the substrate 10 can apply a voltage to the second LED unit 31 individually, so that the second LED unit 31 is driven individually.

[0150] The second conductive protrusion 35 is disposed on the planarization layer 32. Specifically, the second conductive protrusion 35 is disposed on the side of the second LED unit layer 30 facing the substrate 10. This enables one end of the second conductive protrusion 35 to be successfully electrically connected to the second electrode layer 34, and the other end of the second conductive protrusion 35 to be successfully bonded and electrically connected to the second end 262 of the conductive post 26, reducing the processing difficulty.

[0151] It should be noted that the bonding of the first end 261 of the conductive post 26 to the corresponding first contact 11 means that each first contact 11 is only electrically connected to one first LED unit 22 or the second LED unit layer 30. Therefore, each conductive post 26 and each second conductive protrusion 35 are used to connect a second LED unit 31 and the corresponding first contact 11.

[0152] In a possible implementation manner, the material of the second conductive protrusion 35 includes copper (Cu).

[0153] In a possible implementation, the micro-light emitting diode display 1 further includes a second connection layer, which is disposed between the first LED unit layer 20 and the second LED unit layer 30. The second connection layer has a plurality of pads arranged at intervals. In the vertical direction, the pads penetrate the second connection layer. One side of the second connection layer is bonded to the first passivation layer 21, and the other side is bonded to the filling layer 32 of the second LED unit layer 30. One end of the pad is bonded to and electrically connected to the second end 262 of the conductive column 26, and the other end of the pad is bonded to and electrically connected to the second conductive protrusion 35, so as to achieve bonding of the second LED unit layer 30 to the first LED unit layer 20.

[0154] It should be noted that the material of the second connection layer is not limited, for example, silicon dioxide. The material of the solder pad is not limited, for example, copper.

[0155] In some embodiments, in combination Figure 1 and Figure 21 As shown, the surface area of ​​the second conductive protrusion 35 bonding to the conductive pillar 26 is larger than the surface area of ​​the second conductive protrusion 35 connecting to the second electrode layer 34 .

[0156] Figure 21 In the figure, C is used to indicate the bonding side of the second conductive protrusion 35 and the conductive column 26, and D is used to indicate the connection side of the second conductive protrusion 35 and the second electrode layer 34. By making the surface area of ​​the lower end of the second conductive protrusion 35 larger than the surface area of ​​the upper end, the size of the display 1 can be reduced to a certain extent, and the bonding accuracy of the second conductive protrusion 35 and the conductive column 26 can be improved, so that more second LED units 31 can be integrated on the same display area, the pixel density can be improved, and then the resolution and display effect of the device can be improved.

[0157] In some embodiments, the first LED unit 22 and the second LED unit 31 respectively include a first doped semiconductor layer, an active layer, and a second doped semiconductor layer that are stacked. The first doped semiconductor layer is close to the substrate 10. The surface of the second doped semiconductor layer of the first LED unit 22 facing away from the substrate 10 is flush with the surface of the first passivation layer 21 facing away from the substrate 10. The surface of the second doped semiconductor layer of the second LED unit 31 facing away from the substrate 10 is flush with the surface of the second passivation layer 33 facing away from the substrate 10.

[0158] Specifically, the first LED unit 22 includes a first doped semiconductor layer, an active layer, and a second doped semiconductor layer which are stacked. The second LED unit 31 includes a first doped semiconductor layer, an active layer, and a second doped semiconductor layer which are stacked. The first doped semiconductor layer is close to the substrate 10, that is, the second doped semiconductor layer faces away from the substrate 10, enabling the first doped semiconductor layer to be smoothly electrically connected to the substrate 10 and enabling the second doped semiconductor layer to be effectively protected by the first passivation layer 21 or the second passivation layer 33, thereby improving the yield.

[0159] By making the surface of the second doped semiconductor layer of the first LED unit 22 on the side facing away from the substrate 10 flush with the surface of the first passivation layer 21 on the side facing away from the substrate 10, when manufacturing the micro light-emitting diode display 1, the first passivation layer 21 can be used as a processing position reference to protect the second doped semiconductor layer, avoiding or reducing the situation of damaging the second doped semiconductor layer due to overprocessing, reducing the processing difficulty, and improving the overall yield.

[0160] By making the surface of the second doped semiconductor layer of the second LED unit 31 on the side facing away from the substrate 10 flush with the surface of the second passivation layer 33 on the side facing away from the substrate 10, when manufacturing the micro light-emitting diode display 1, the second passivation layer 33 can be used as a processing position reference to protect the second doped semiconductor layer, avoiding or reducing the situation of damaging the second doped semiconductor layer due to overprocessing, reducing the processing difficulty, and improving the overall yield.

[0161] The first doped semiconductor layer can be a p-type semiconductor layer. For example, specifically, it can be p-type gallium nitride (GaN) or p-type aluminum indium gallium nitride (AlInGaN). Correspondingly, the second doped semiconductor layer can be an n-type semiconductor layer. For example, specifically, it can be n-type gallium nitride (GaN) or n-type aluminum indium gallium nitride (AlInGaN).

[0162] In some embodiments, the substrate 10 includes at least one second contact (not shown in the figure). The micro light-emitting diode display 1 further includes a common electrode layer 40. The common electrode layer 40 is electrically connected to the surfaces of the first LED unit 22 and the second LED unit 31 on the side facing away from the substrate 10, and the common electrode layer 40 is electrically connected to the second contact.

[0163] Specifically, the common electrode layer 40 can cover the surface of the first LED unit 22 on the side facing away from the substrate 10 and be electrically connected to the first LED unit 22. At the same time, the common electrode layer 40 also covers the surface of the second LED unit 31 on the side facing away from the substrate 10 and is electrically connected to the second LED unit 31. By electrically connecting the first LED unit 22 and the second LED unit 31 to the surface on the side facing away from the substrate 10 through the same common electrode layer 40, the thickness of the display 1 in the vertical direction is reduced, and the overall size of the display 1 is reduced.

[0164] It is electrically connected to the second contact through the common electrode layer 40, and each first LED unit 22 and each second LED unit 31 are individually electrically connected to the corresponding first contact 11, so that each first LED unit 22 and each second LED unit 31 are individually driven.

[0165] In a specific example, the first contact 11 is an anode metal contact, and the second contact is a cathode metal contact. The first doped semiconductor layer is a p-type semiconductor layer, and the second doped semiconductor layer is an n-type semiconductor layer. A first contact 11 is electrically connected to the first doped semiconductor layer of a first LED unit 22 through a first conductive bump 24 and a first electrode layer 25. The second doped semiconductor layers of multiple first LED units 22 are electrically connected to the second contact through the common electrode layer 40 (forming a common cathode structure) to drive the active layer of the first LED unit 22 to emit light, for example, emitting green light, blue light or red light.

[0166] In another specific example, the first contact 11 is an anode metal contact, and the second contact is a cathode metal contact. The first doped semiconductor layer is a p-type semiconductor layer, and the second doped semiconductor layer is an n-type semiconductor layer. A first contact 11 is electrically connected to the first doped semiconductor layer of a second LED unit 31 through a conductive post 26, a second conductive bump 35 and a second electrode layer 34. The second doped semiconductor layers of multiple second LED units 31 are electrically connected to the second contact through the common electrode layer 40 (forming a common cathode structure) to drive the active layer of the second LED unit 31 to emit light, for example, emitting green light, blue light or red light.

[0167] It should be noted that the common electrode layer 40 is specifically a transparent common electrode layer 40 to enable the light of the first LED unit 22 and the second LED unit 31 to be emitted smoothly. The material of the common electrode layer 40 is not limited. For example, it can be indium tin oxide (ITO).

[0168] In some embodiments, as shown in Figure 1 the display 1 further includes a plurality of color conversion units 42. The plurality of color conversion units 42 are arranged at intervals on the side of the second LED unit layer 30 away from the substrate 10 and are located on some of the first LED units 22 or some of the second LED units 31. The color conversion unit 42 is used to convert the first color light emitted by the first LED unit 22 or the second color light emitted by the second LED unit 31 into a third color light. The first color light, the second color light and the third color light are different. Among them, at least one first LED unit 22, at least one adjacent second LED unit 31 and at least one adjacent color conversion unit 42 form a full-color pixel.

[0169] A plurality of color conversion units 42 are arranged at intervals on the side of the second LED unit layer 30 away from the substrate 10 and are located above some of the first LED units 22 or some of the second LED units 31. Specifically, color conversion units 42 are provided on some of the first LED units 22 among the plurality of first LED units 22, and / or color conversion units 42 are provided on some of the second LED units 31 among the plurality of second LED units 31. Of course, the vertical projection of the color conversion unit 42 on the substrate 10 with the underlying first LED unit 22 may partially or completely overlap, and the vertical projection of the color conversion unit 42 on the substrate 10 with the underlying second LED unit 31 may partially or completely overlap.

[0170] When the color conversion unit 42 is located above the first LED unit 22, the color conversion unit 42 is configured to convert the first color light emitted by the first LED unit 22 into a third color light. For example, the color conversion unit 42 converts the green light emitted by the first LED unit 22 into red light.

[0171] When the color conversion unit 42 is located above the second LED unit 31, the color conversion unit 42 is configured to convert the second color light emitted by the second LED unit 31 into a third color light. For example, the color conversion unit 42 converts the blue light emitted by the second LED unit 31 into red light.

[0172] At least one first LED unit 22, at least one adjacent second LED unit 31, and at least one adjacent color conversion unit 42 form a full-color pixel. That is, full-color display is achieved through the first color light emitted by the first LED unit 22, the second color light emitted by at least one adjacent second LED unit 31, and the third color light emitted after conversion by at least one adjacent color conversion unit 42. By hybrid bonding the first LED unit layer 20 to the substrate 10, hybrid bonding the second LED unit layer 30 to the first LED unit layer 20, and performing color conversion by the color conversion unit 42, that is, through two hybrid bondings and one color conversion, the light-emitting efficiency is improved and the processing difficulty is reduced.

[0173] Exemplarily, as Figure 1 shown, among three adjacent sub-pixels, one is provided with a first LED unit 22 for emitting green light. One is provided with a second LED unit 31 for emitting blue light. One is provided with a second LED unit 31, and a color conversion unit 42 is provided on the second LED unit 31. The color conversion unit 42 is configured to convert the blue light emitted by the second LED unit 31 into red light for emission, so as to achieve full-color display, improve the light-emitting efficiency, simplify the manufacturing process, and reduce the processing difficulty and processing cost.

[0174] In a possible implementation manner, the material of the color conversion unit 42 includes quantum dot photoresist (QDPR).

[0175] In a possible implementation, in combination with Figure 1 and Figure 25 as shown, the micro light-emitting diode display 1 further includes a protective layer 41. The protective layer 41 is disposed on the common electrode layer 40 and covers at least the common electrode layer 40. The color conversion unit 42 is disposed on the protective layer 41.

[0176] The integrity and stability of the display 1 can be improved through the protective layer 41, and the light extraction rate can be increased.

[0177] It should be noted that the protective layer 41 is specifically a transparent protective layer 41, which enables the display 1 to emit light effectively while protecting the device.

[0178] In a possible implementation, the material of the protective layer 41 includes polyimide, benzocyclobutene (BCB), or planarizing glue.

[0179] In some embodiments, in combination with Figure 25 as shown, the display 1 further includes a third LED unit layer 50. The third LED unit layer 50 is bonded to the second LED unit layer 30. The third LED unit layer 50 includes a plurality of third LED units 51 arranged at intervals. The vertical projections of the first LED unit 22, the second LED unit 31, and the third LED unit 51 on the substrate 10 do not overlap. Among them, at least one first LED unit 22, at least one adjacent second LED unit 31, and at least one adjacent third LED unit 51 form a full-color pixel.

[0180] The vertical projections of the first LED unit 22, the second LED unit 31, and the third LED unit 51 on the substrate 10 do not overlap, so as to enable the first LED unit 22, the second LED unit 31, and the third LED unit 51 to emit light independently, improve the light emission efficiency, and reduce crosstalk. Among them, the first LED unit 22 emits first-color light, the second LED unit 31 emits second-color light, and the third LED unit 51 emits third-color light. The first-color light, the second-color light, and the third-color light are different, so as to achieve full-color display, improve the color response speed and long-term stability. For example, the first-color light is green light, the second-color light is blue light, and the third-color light is red light. Another example is that the first-color light is green light, the second-color light is red light, and the third-color light is blue light. Another example is that the first-color light is blue light, the second-color light is green light, and the third-color light is red light. Another example is that the first-color light is blue light, the second-color light is red light, and the third-color light is green light. Another example is that the first-color light is red light, the second-color light is green light, and the third-color light is blue light. Another example is that the first-color light is red light, the second-color light is blue light, and the third-color light is green light.

[0181] A full-color pixel is formed by at least one first LED unit 22, at least one adjacent second LED unit 31, and at least one adjacent third LED unit 51. That is, full-color display is achieved by the first LED unit 22 emitting first-color light, at least one adjacent second LED unit 31 emitting second-color light, and at least one adjacent third LED unit 51 emitting third-color light.

[0182] In a possible implementation, in combination with Figure 25 as shown, the third LED unit layer 50 further includes a filling layer 53 located between adjacent third LED units 51. The filling layer 53 is bonded to the second passivation layer 33 to bond the third LED unit layer 50 to the second LED unit layer 30.

[0183] In a possible implementation, in combination with Figure 25 as shown, the third LED unit layer 50 further includes a third passivation layer 52, which is disposed on the surface of the filling layer 53 facing away from the substrate 10 and exposes the surfaces of a plurality of third LED units 51 facing away from the substrate 10. And the third passivation layer 52 covers at least the sides of a plurality of third LED units 51.

[0184] When manufacturing the display 1, the third passivation layer 52 is used as a processing position reference, reducing the processing difficulty and cost, and avoiding or reducing the damage of the device caused by overprocessing, so as to protect the third LED units 51 during the processing and improve the overall yield.

[0185] The third passivation layer 52 covers at least the sides of a plurality of third LED units 51. For example, the third passivation layer 52 can cover the sides of a plurality of third LED units 51 and partial surfaces of a plurality of third LED units 51 facing the substrate 10 side. To protect the third LED units 51 and when the third LED units 51 are connected to electrodes, the third passivation layer 52 can also avoid or reduce leakage, improving the stability and reliability of the display 1.

[0186] In a possible implementation, the material of the third passivation layer 52 includes aluminum oxide ( ), or silicon dioxide ( ).

[0187] In a possible implementation, in combination with Figure 25As shown, the third LED unit layer 50 further includes a third electrode 54. The third electrode 54 is disposed on a side of the third passivation layer 52 away from the third LED unit 51, and surrounds the side surface and the side facing the substrate 10 of the third LED unit 51. Moreover, the third electrode 54 covers the surface of the position on the side of the third LED unit 51 facing the substrate 10 and not covered by the third passivation layer 52. The third electrode 54 reflects the light emitted by the third LED unit 51. For the technical effects of the third electrode 54, reference may be made to the technical effects of the second electrode layer 34 and the first electrode layer 25 in the foregoing embodiments, which will not be elaborated herein.

[0188] In a possible implementation, in combination with Figure 25 As shown, the display 1 further includes a conductive connection post 55. The conductive post 26 vertically penetrates the second LED unit layer 30. The third LED unit layer 50 further includes a third conductive protrusion 56. One end of the conductive connection post 55 is bonded and electrically connected to the conductive post 26, and the other end of the conductive connection post 55 is bonded and electrically connected to the third conductive protrusion 56. The end of the third conductive protrusion 56 away from the conductive connection post 55 is bonded and electrically connected to the third electrode 54, so that the third LED unit layer 50 can be independently driven by the substrate 10.

[0189] In a possible implementation, in combination with Figure 25 As shown, the common electrode layer 40 is also electrically connected to the surface of the third LED unit 51 away from the substrate 10.

[0190] In combination with Figure 26 As shown, according to the second aspect of the embodiments of the present application, a method for manufacturing a micro light-emitting diode display 1 is provided for manufacturing the display 1. The manufacturing method includes the following steps:

[0191] S261. Provide a substrate.

[0192] As Figure 1 and Figures 18 to 25 shown, the substrate 10 enables the individual driving of the first LED unit 22 and the plurality of second LED units 31.

[0193] S262. Fabricate a first LED unit layer, the first LED unit layer including a first passivation layer and a plurality of first LED units arranged at intervals; the first passivation layer is located on the surface of the first LED unit layer away from the substrate side, and exposes the surfaces of the plurality of first LED units away from the substrate side; and the first passivation layer further covers at least the side surfaces of the plurality of first LED units.

[0194] In combination with Figures 1 to 9As shown, by preparing the first LED unit layer 20, it is to prepare for bonding the whole of the first LED unit layer 20 to the substrate 10, and improve the yield of each structure in the first LED unit layer 20 during the processing. Among them, for the technical effects of the first passivation layer 21, the first LED units 22 and the settings, refer to the foregoing embodiments and will not be elaborated here.

[0195] S263. Bond the first LED unit layer to the substrate.

[0196] Combine Figure 18 and Figure 19 As shown, by bonding the whole of the first LED unit layer 20 to the substrate 10, the processing technology is simplified, the processing difficulty is reduced, and the yield is improved.

[0197] S264. Prepare the second LED unit layer. The second LED unit layer includes a plurality of second LED units arranged at intervals and a filling layer located between adjacent second LED units.

[0198] Combine Figure 1 and Figures 10 to 17 As shown, by preparing the second LED unit layer 30, it is to prepare for bonding the whole of the second LED unit layer 30 to the first LED unit layer 20, and improve the yield of each structure in the second LED unit layer 30 during the processing. Among them, for the technical effects of the filling layer 32, the first LED units 22 and the settings, refer to the foregoing embodiments and will not be elaborated here.

[0199] S265. Bond the second LED unit layer to the first LED unit layer, wherein the filling layer is bonded to the first passivation layer.

[0200] Among them, a plurality of first LED units 22 and a plurality of second LED units 31 are respectively electrically connected to the substrate 10 to achieve individual driving.

[0201] Combine Figures 20 to 21 As shown, by bonding the whole of the second LED unit layer 30 to the first LED unit layer 20, the processing technology is simplified, the processing difficulty is reduced, and the yield is improved.

[0202] In some embodiments, combine Figures 2 to 4 As shown, the steps of preparing the first LED unit layer 20 include: providing a first substrate 27, on which a first LED epitaxial layer 28 is provided. Etch the side of the first LED epitaxial layer 28 away from the first substrate 27 to form a plurality of first LED units 22. Form a first passivation layer 21, and the first passivation layer 21 covers the surface of the first LED epitaxial layer 28 on the side away from the first substrate 27 and the surfaces of the plurality of first LED units 22, and exposes a part of the surfaces of the plurality of first LED units 22 on the side away from the first substrate 27.

[0203] As shown in Figure 2 FIG. 1, the entire first LED unit layer 20 structure is made more stable by providing support through the first substrate 27. For example, the first LED epitaxial layer 28 can be grown on the first substrate 27, and the first substrate 27 provides stable support for the growth of the first LED epitaxial layer 28.

[0204] It should be noted that the material of the first substrate 27 is not limited. For example, it can be silicon, sapphire, or gallium nitride. The material of the first LED epitaxial layer 28 is not limited. For example, it can be gallium nitride (GaN).

[0205] As shown in Figure 3 FIG. 2, by etching the side of the first LED epitaxial layer 28 facing away from the first substrate 27, a plurality of mesa structures (MESA) are formed in the first LED epitaxial layer 28. Each mesa structure is a complete first LED unit 22, that is, the first LED unit 22 can be independently driven and emit light by the substrate 10. Specifically, a plurality of first LED units 22 are arranged at intervals.

[0206] As shown in Figure 4 FIG. 3, a first passivation layer 21 can be formed on the surface of the first LED epitaxial layer 28 facing away from the first substrate 27 by depositing materials (such as alumina or silica), so that the first passivation layer 21 covers the surface of the first LED epitaxial layer 28 facing away from the first substrate 27 and the surfaces of a plurality of first LED units 22. The first passivation layer 21 is etched to form a plurality of windows, Figure 4 where G1 in FIG. 3 is used to indicate the windows formed by etching the first passivation layer 21. The plurality of windows respectively expose partial surfaces of a plurality of first LED units 22 facing away from the first substrate 27, preparing the structure for the subsequent electrical connection between the first LED units 22 and the first electrode layer 25.

[0207] In some embodiments, as shown in Figures 5 to 9 FIG. 4, the steps of preparing the first LED unit layer 20 further include: forming a first electrode layer 25 on the side of the first passivation layer 21 facing away from the first LED units 22. The first electrode layer 25 surrounds the side surfaces and the side facing away from the first substrate 27 of the first LED units 22, and the first electrode layer 25 covers the surface of the area of the first LED units 22 facing away from the first substrate 27 and not covered by the first passivation layer 21. A planarization layer 23 is formed, and the planarization layer 23 covers the first passivation layer 21 and the first electrode layer 25. A first conductive bump 24 and a conductive pillar 26 are formed. One end of the first conductive bump 24 is connected to the first electrode layer 25, and the other end extends vertically to the surface of the planarization layer 23 facing away from the first substrate 27; the conductive pillar 26 penetrates through the planarization layer 23 and the first passivation layer 21 vertically.

[0208] Specifically, as shown in Figure 5As shown, materials can be deposited on the side of the first passivation layer 21 facing away from the first substrate 27 to form a metal layer. The metal layer can cover the surface of the area of the first LED unit 22 facing away from the first substrate 27 and not covered by the first passivation layer 21. The metal layer is processed by a photolithography patterning process to form a first electrode layer 25, so that the first electrode layer 25 surrounds the side surface of the first LED unit 22 and the side of the first LED unit 22 facing away from the first substrate 27.

[0209] As Figure 6 shown, after forming the first electrode layer 25, materials (such as silicon dioxide) are deposited on the surface of the first passivation layer 21 facing away from the first substrate 27 to form a planarization layer 23, so that the planarization layer 23 covers the first passivation layer 21 and the first electrode layer 25. As Figure 7 shown, the planarization layer 23 corresponding to the first electrode layer 25 is etched, and the planarization layer 23 corresponding to the conductive post 26 and the first passivation layer 21 are etched to form a plurality of through holes ( Figure 7 G2 in is used to indicate the through holes) to prepare the structure for forming the first conductive bump 24 and the conductive post 26. As Figure 8 shown, materials (such as copper) are filled in the plurality of through holes. The filling method of the materials is not limited. For example, it can be filled by deposition and electroplating (Cu Seed Deposition and Plating). As Figure 9 shown, after filling the materials, part of the planarization layer 23 and part of the filled materials are removed by chemical mechanical polishing (CMP) to obtain the first conductive bump 24, the conductive post 26 and the planarization layer 23 after CMP processing, and one end of the first conductive bump 24 is connected to the first electrode layer 25. The other end of the first conductive bump 24 extends vertically to the surface of the planarization layer 23 after CMP processing facing away from the first substrate 27, and the conductive post 26 vertically penetrates the first passivation layer 21 and the planarization layer 23 after CMP processing.

[0210] Combined with Figures 2 to 9 and Figure 27 shown, in a possible implementation manner, a method for preparing the first LED unit layer 20 is provided, including:

[0211] S271. Provide a first substrate, and a first LED epitaxial layer is disposed on the first substrate.

[0212] S272. Etch the first LED epitaxial layer to form a plurality of first LED units.

[0213] S273. Form a first passivation layer, and the first passivation layer covers the surface of the etched first LED epitaxial layer and exposes part of the surface of the plurality of first LED units facing away from the first substrate side.

[0214] S274. A first electrode layer is formed on the side of the first passivation layer facing away from the first LED unit. The first electrode layer surrounds the side surface and the side facing away from the first substrate of the first LED unit, and the first electrode layer also covers the surface of the area on the side of the first LED unit facing away from the first substrate and not covered by the first passivation layer.

[0215] S275. A planarization layer is formed to cover the first passivation layer and the first electrode layer.

[0216] S276. A first conductive bump and a conductive column are formed. One end of the first conductive bump is connected to the first electrode layer, and the other end extends vertically to the surface of the planarization layer on the side facing away from the first substrate; the conductive column penetrates through the planarization layer and the first passivation layer vertically.

[0217] In the method for manufacturing the first LED unit layer 20, for the implementation manners and technical effects of each step and each structure, refer to the foregoing embodiments, and details are not described herein again.

[0218] In some embodiments, as shown in Figures 18 to 19 the step of bonding the first LED unit layer 20 to the substrate 10 includes: bonding the planarization layer 23 to the substrate 10, and bonding and electrically connecting the first conductive bump 24 and the conductive column 26 to the corresponding first contact 11. The first substrate 27 and a part of the first LED epitaxial layer 28 are removed until the surface of the first passivation layer 21 is exposed, so that the surfaces of the first passivation layer 21, the first LED unit 22, and the conductive column 26 on the side facing away from the substrate 10 are flush.

[0219] As shown in Figure 18 by bonding the planarization layer 23 to the substrate 10, and bonding and electrically connecting the first conductive bump 24 and the conductive column 26 to the corresponding first contact 11, the first hybrid bonding is realized. The processing technology is simple, the processing difficulty is reduced, the overall yield is improved, and the size of the display 1 is reduced.

[0220] As shown in Figure 18 and Figure 19 it can be seen that the first substrate 27 and a part of the first LED epitaxial layer 28 can be removed by chemical mechanical polishing (CMP) until the surface of the first passivation layer 21 is exposed, so that the surfaces of the first passivation layer 21, the first LED unit 22, and the conductive column 26 on the side facing away from the substrate 10 are flush, preparing for bonding the second LED unit layer 30 to the first LED unit layer 20.

[0221] During the CMP processing, the first passivation layer 21 is used as the processing reference, that is, the processing stops when the surface of the first passivation layer 21 is exposed. The processing difficulty and processing cost are reduced, the situation of device damage caused by overprocessing is avoided or reduced, and the first LED unit 22 is effectively protected during the processing, improving the overall yield.

[0222] Combined with Figures 10 to 17 and Figure 28 As shown, in some embodiments, a method for preparing a second LED unit layer 30 is provided, including:

[0223] S281. Provide a second substrate, on which a second LED epitaxial layer is provided.

[0224] Combined with Figure 10 As shown, through the support provided by the second substrate 36, the entire structure of the second LED unit layer 30 is made more stable. For example, a second LED epitaxial layer 37 can be grown on the second substrate 36, so that the second substrate 36 provides stable support for the growth of the second LED epitaxial layer 37.

[0225] It should be noted that the material of the second substrate 36 is not limited. For example, it can be silicon, sapphire or gallium nitride. The material of the second LED epitaxial layer 37 is not limited. For example, it can be gallium nitride (GaN).

[0226] S282. Etch the second LED epitaxial layer to form a plurality of second LED units.

[0227] Combined with Figure 11 As shown, by etching the side of the second LED epitaxial layer 37 facing away from the second substrate 36, a plurality of mesa structures (MESA) are formed in the second LED epitaxial layer 37. Each mesa structure can form a complete second LED unit 31, so that the second LED unit 31 can be independently driven and emit light by the substrate 10. Specifically, a plurality of second LED units 31 are arranged at intervals.

[0228] S283. Form a second passivation layer, which covers the surface of the etched second LED epitaxial layer and exposes a part of the surface of the plurality of second LED units facing away from the second substrate side.

[0229] Combined with Figure 12 As shown, a second passivation layer 33 can be formed on the surface of the second LED epitaxial layer 37 facing away from the second substrate 36 by depositing materials (such as alumina or silicon dioxide), so that the second passivation layer 33 covers the surface of the second LED epitaxial layer 37 facing away from the second substrate 36 and the surfaces of the plurality of second LED units 31.

[0230] Etch the second passivation layer 33 to form a plurality of windows. Figure 12 G3 in is used to indicate the windows formed by etching the second passivation layer 33. The plurality of windows respectively expose a part of the surface of the plurality of second LED units 31 facing away from the second substrate 36, and prepare the structure for the subsequent electrical connection between the second LED units 31 and the second electrode layer 34.

[0231] S284. A second electrode layer is formed on a side of the second passivation layer facing away from the second LED unit. The second electrode layer surrounds the side surface and the side facing away from the second substrate of the second LED unit, and the second electrode layer covers the surface of the region of the second LED unit facing away from the second substrate and not covered by the second passivation layer.

[0232] Combined with Figure 13 As shown, a material is deposited on a side of the second passivation layer 33 facing away from the second substrate 36 to form a metal layer. The metal layer can cover the surface of the region of the second LED unit 31 facing away from the second substrate 36 and not covered by the second passivation layer 33. The metal layer is processed by a photolithography patterning process to form a second electrode layer 34, so that the second electrode layer 34 surrounds the side surface and the side of the second LED unit 31 facing away from the second substrate 36.

[0233] S285. A planarization layer is formed to cover the second passivation layer and the second electrode layer.

[0234] Combined with Figure 14 As shown, after the second electrode layer 34 is formed, a material (such as silicon dioxide) is deposited on the surface of the second passivation layer 33 facing away from the second substrate 36 to form a planarization layer 32, so that the planarization layer 32 covers the second passivation layer 33 and the second electrode layer 34.

[0235] S286. A second conductive bump is formed on the planarization layer. One end of the second conductive bump is electrically connected to the second electrode layer, and the other end extends vertically to the surface of the planarization layer facing away from the second substrate side.

[0236] Combined with Figure 15 As shown, the planarization layer 32 is etched to form a plurality of through holes for structural preparation for forming the second conductive bump 35. Figure 15 G4 in Figure 16 is used for the through holes formed by etching the planarization layer 32. As Figure 17 shown, a material (such as copper) is filled in the plurality of through holes. The filling method of the filling material is not limited. For example, it can be filled by deposition and electroplating (Cu Seed Deposition and Plating). As

[0237] In some embodiments, as Figure 20 and Figure 21As shown, the micro light-emitting diode display 1 further includes conductive posts 26. The step of bonding the second LED unit layer 30 to the first LED unit layer 20 includes: bonding the planarization layer 32 to the first passivation layer 21, and bonding and electrically connecting the second conductive protrusion 35 to one end of the conductive post 26 facing away from the substrate 10. Remove the second substrate 36 and part of the second LED epitaxial layer 37 until the surface of the second passivation layer 33 is exposed, so that the surface of the second passivation layer 33 is flush with the surface of the second LED unit 31 on the side facing away from the substrate 10.

[0238] As Figure 20 shown, by bonding the planarization layer 32 to the first passivation layer 21, and bonding and electrically connecting the second conductive protrusion 35 to one end of the conductive post 26 facing away from the substrate 10, the second hybrid bonding is achieved. The processing technology is simple, the processing difficulty is reduced, the overall yield is improved, and the size of the display 1 is reduced.

[0239] As Figure 21 shown, the second substrate 36 and part of the second LED epitaxial layer 37 can be removed by chemical mechanical polishing (CMP) until the surface of the second passivation layer 33 is exposed, so that the surface of the second passivation layer 33 is flush with the surface of the second LED unit 31 on the side facing away from the substrate 10, providing a structural preparation for the subsequent formation of the common electrode layer 40.

[0240] During the CMP processing, the second passivation layer 33 is used as the processing reference, that is, the processing stops when the surface of the second passivation layer 33 is exposed. This reduces the processing difficulty and cost of the processing technology, avoids or reduces the damage to the device caused by overprocessing, and effectively protects the second LED unit 31 during the processing, improving the overall yield.

[0241] In some embodiments, as Figure 22 shown, after the step of bonding the second LED unit layer 30 to the first LED unit layer 20, the preparation method further includes: etching the second LED unit layer 30 to expose the surface of the first LED unit 22 on the side facing away from the substrate 10. Form a common electrode layer 40, and the common electrode layer 40 covers at least the surfaces of the first LED unit 22 and the second LED unit 31 on the side facing away from the substrate 10, and the common electrode layer 40 is electrically connected to the second contact of the substrate 10.

[0242] As Figure 22As shown, by etching the second LED unit layer 30, a plurality of windows are formed in the second LED unit layer 30, and the plurality of windows respectively expose the surfaces of the plurality of first LED units 22 facing away from the substrate 10. A material (such as ITO) is deposited on the surface of the second LED unit layer 30 facing away from the substrate 10 and on the surfaces at the plurality of windows of the second LED unit layer 30 to form a common electrode layer 40. The common electrode layer 40 is made to cover at least the surfaces of the plurality of first LED units 22 and the plurality of second LED units 31 facing away from the substrate 10. And the common electrode layer 40 is electrically connected to the second contact of the substrate 10.

[0243] It can be understood that the specific connection manner between the common electrode layer 40 and the second contact of the substrate 10 is not limited, as long as the common electrode layer 40 can be electrically connected to the second contact of the substrate 10.

[0244] Combined with Figures 2 to 22 and Figure 29 As shown, in a possible implementation, a method for manufacturing a micro light-emitting diode display 1 is provided, including the following steps:

[0245] S291. Provide a substrate.

[0246] S292. Prepare a first LED unit layer, the first LED unit layer includes a first passivation layer and a plurality of first LED units arranged at intervals; the first passivation layer is located on the surface of the first LED unit layer facing away from the substrate and exposes the surfaces of the plurality of first LED units facing away from the substrate; and the first passivation layer also covers at least the sides of the plurality of first LED units.

[0247] S293. Bond the first LED unit layer to the substrate.

[0248] S294. Prepare a second LED unit layer, the second LED unit layer includes a plurality of second LED units arranged at intervals and a filling layer located between adjacent second LED units.

[0249] S295. Bond the second LED unit layer to the first LED unit layer, wherein the filling layer is bonded to the first passivation layer. Among them, the plurality of first LED units and the plurality of second LED units are respectively electrically connected to the substrate to achieve individual driving.

[0250] S296. Etch the second LED unit layer to expose the surface of the first LED unit facing away from the substrate.

[0251] S297. Form a common electrode layer, the common electrode layer covers at least the surfaces of the first LED unit and the second LED unit facing away from the substrate, and the common electrode layer is electrically connected to the second contact of the substrate.

[0252] In the preparation method of this embodiment, for the implementation manners and technical effects of each step and each structure, refer to the foregoing embodiments, and details are not described herein again.

[0253] In some embodiments, as shown in Figure 1 , Figure 23 and Figure 24 , the preparation method further includes: forming a protective layer 41, and the protective layer 41 covers at least the common electrode layer 40. A color conversion unit 42 is formed on the protective layer 41, and the color conversion unit 42 is located on a part of the first LED units 22 or a part of the second LED units 31.

[0254] As shown in Figure 23 , a material (such as polyimide) is coated (for example, spin-coated) on the side of the common electrode layer 40 facing away from the substrate 10 to form a protective layer 41, so that the protective layer 41 covers at least the common electrode layer 40.

[0255] As shown in Figure 24 , the protective layer 41 is etched to form a plurality of windows in the protective layer 41, providing a structural preparation for forming the color conversion unit 42. Figure 24 G5 in Figure 1 is used to indicate the windows formed by etching the protective layer 41. As shown in

[0256] and Figures 1 to 24 as well as Figure 30 , in a possible implementation manner, a preparation method of a micro light-emitting diode display 1 is provided, including the following steps:

[0257] S301. Provide a substrate.

[0258] S302. Prepare a first LED unit layer, where the first LED unit layer includes a first passivation layer and a plurality of first LED units arranged at intervals; the first passivation layer is located on the surface of the first LED unit layer facing away from the substrate side and exposes the surfaces of the plurality of first LED units facing away from the substrate side; and the first passivation layer also covers at least the side surfaces of the plurality of first LED units.

[0259] S303. Bond the first LED unit layer to the substrate.

[0260] S304. Prepare a second LED unit layer, where the second LED unit layer includes a plurality of second LED units arranged at intervals and a filling layer located between adjacent second LED units.

[0261] S305. Bond the second LED unit layer to the first LED unit layer, where the filling layer is bonded to the first passivation layer.

[0262] Among them, the plurality of first LED units 22 and the plurality of second LED units 31 are respectively electrically connected to the substrate 10 to achieve individual driving.

[0263] S306. Etch the second LED unit layer to expose the surface of the first LED unit facing away from the substrate.

[0264] S307. Form a common electrode layer, where the common electrode layer covers at least the surfaces of the first LED unit and the second LED unit facing away from the substrate, and the common electrode layer is electrically connected to the second contact of the substrate.

[0265] S308. Form a protective layer, where the protective layer covers at least the common electrode layer.

[0266] S309. Form a color conversion unit in the protective layer, where the color conversion unit is located above some of the first LED units or some of the second LED units.

[0267] In the preparation method of this embodiment, for the implementation manners and technical effects of each step and each structure, refer to the foregoing embodiments and will not be elaborated here.

[0268] It should be noted that the steps involved in the preparation method of the embodiments of the present application are not limited to the order of operation execution. For example, steps S302 and S304 can be basically executed in parallel. For another example, step S304 can be executed before step S303.

[0269] The embodiments of the present application also provide a display device. The display device includes the micro light-emitting diode display 1 according to any one of the previous embodiments. Therefore, the display device has the beneficial effects of the micro light-emitting diode display 1 according to any one of the previous embodiments, which will not be elaborated here.

[0270] It should be noted that the micro light-emitting diode display 1 or the display device can be applied to devices such as augmented reality (AR) display devices, virtual reality (VR) display devices, near-eye display (NED) devices, and head-up display (HUD) devices.

[0271] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above is only the preferred implementation manner of the present application. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the technical principle of the present application, several improvements and modifications can still be made, and these improvements and modifications should also be regarded as within the protection scope of the present application.

Claims

1. A micro light-emitting diode display, characterized in that, Comprising: Substrate; The first LED unit layer, bonded to the substrate, includes a first passivation layer and a plurality of first LED units arranged at intervals; The first passivation layer is located on the surface of the first LED unit layer facing away from the substrate side, and exposes the surfaces of the plurality of first LED units facing away from the substrate side; and the first passivation layer further covers at least the sides of the plurality of first LED units. The first passivation layer serves as a processing position reference, and the surface of the first passivation layer is flush with the surface of the first LED unit facing away from the substrate side. The first LED unit layer further includes a first electrode layer, which is disposed on the side of the first passivation layer facing away from the first LED unit and surrounds the sides and the side facing the substrate of the first LED unit to form a reflective cup on the side and the bottom surface of the first LED unit. The first electrode layer covers the surface of the area of the first LED unit facing the substrate side and not covered by the first passivation layer. The first electrode layer is electrically connected to the first LED unit, and the first electrode layer reflects the light emitted by the first LED unit; The second LED unit layer, bonded to the first LED unit layer, includes a plurality of second LED units arranged at intervals and a filling layer located between adjacent second LED units. The filling layer is bonded to the first passivation layer; Wherein, the plurality of first LED units and the plurality of second LED units are respectively electrically connected to the substrate to achieve individual driving.

2. The micro light-emitting diode display according to claim 1, wherein The substrate includes a plurality of first contacts, and the first LED unit layer further includes: A planarization layer, disposed on the side of the first passivation layer facing the substrate and bonded to the substrate; A first conductive protrusion, one end of which is electrically connected to the first LED unit, and the other end is bonded and electrically connected to the corresponding first contact.

3. The micro light-emitting diode display according to claim 1, wherein The second LED unit layer further includes: A second passivation layer, disposed on the surface of the filling layer facing away from the substrate side, and exposes the surfaces of the plurality of second LED units facing away from the substrate side; and the second passivation layer further covers at least the sides of the plurality of second LED units.

4. The micro light-emitting diode display according to claim 3, wherein The second LED unit layer further includes: A second electrode layer, disposed on the side of the second passivation layer facing away from the second LED unit and surrounding the sides and the side facing the substrate of the second LED unit; And, the second electrode layer covers the surface of the position of the second LED unit facing the substrate side and not covered by the second passivation layer, and the second electrode layer reflects the light emitted by the second LED unit.

5. The micro light-emitting diode display according to claim 1, characterized in that, Further comprising: A conductive column, vertically penetrating the first LED unit layer, one end of the conductive column is electrically connected to the substrate, and the other end of the conductive column is electrically connected to the corresponding second LED unit.

6. The micro light emitting diode display according to claim 5, characterized in that, The second LED unit layer further includes: A second conductive protrusion, electrically connected to the second LED unit; Wherein, the conductive column is electrically connected to the second LED unit through the second conductive protrusion.

7. The micro light emitting diode display according to claim 1, characterized in that The first LED unit and the second LED unit respectively include a first doped semiconductor layer, an active layer, and a second doped semiconductor layer which are stacked, and the first doped semiconductor layer is close to the substrate; A surface of the second doped semiconductor layer of the first LED unit facing away from the substrate is flush with a surface of the first passivation layer facing away from the substrate.

8. The micro light-emitting diode display according to claim 1, wherein The substrate includes at least one second contact, and the micro light emitting diode display further includes: The common electrode layer is electrically connected to the surfaces of the first LED unit and the second LED unit that are away from the substrate, and the common electrode layer is electrically connected to the second contact point.

9. The micro light-emitting diode display according to claim 1, characterized in that, Also includes: a plurality of color conversion units, located on part of the first LED unit or part of the second LED unit, the color conversion units being used to convert a first color light emitted by the first LED unit or a second color light emitted by the second LED unit into a third color light, wherein the first color light, the second color light and the third color light are different; Wherein, at least one first LED unit, at least one adjacent second LED unit and at least one adjacent color conversion unit form a full-color pixel point.

10. The micro light-emitting diode display according to claim 1, wherein Also includes: A third LED unit layer, bonded to the second LED unit layer, includes a plurality of third LED units arranged at intervals, wherein vertical projections of the first LED unit, the second LED unit and the third LED unit on the substrate do not overlap; Wherein, at least one first LED unit, at least one adjacent second LED unit, and at least one adjacent third LED unit form a full-color pixel point.

11. A method for preparing a micro light-emitting diode display, characterized in that, The steps include: providing a substrate; Prepare a first LED unit layer, the first LED unit layer includes a first passivation layer and a plurality of first LED units arranged at intervals; the first passivation layer is located on the surface of the first LED unit layer away from the substrate side, and exposes the surfaces of the plurality of first LED units away from the substrate side; and the first passivation layer also covers at least the side surfaces of the plurality of first LED units; the first LED unit layer also includes a first electrode layer, the first electrode layer is arranged on the side of the first passivation layer away from the first LED unit, and is surrounded by the side surface of the first LED unit and the side facing the substrate to form a reflective cup on the side surface and bottom surface of the first LED unit, the first electrode layer covers the surface of the first LED unit facing the substrate side and not covered by the first passivation layer, the first electrode layer is electrically connected to the first LED unit, and the first electrode layer reflects the light emitted by the first LED unit; Bonding the first LED unit layer to the substrate, with the first passivation layer serving as a processing position reference, and the first passivation layer and the surface of the first LED unit facing away from the substrate being flush; Prepare a second LED unit layer, wherein the second LED unit layer includes a plurality of second LED units arranged at intervals and a filling layer located between adjacent second LED units; Bond the second LED unit layer onto the first LED unit layer, wherein the planarizing layer is bonded to the first passivation layer; Wherein, a plurality of the first LED units and a plurality of the second LED units are respectively electrically connected to the substrate to achieve individual driving.

12. The preparation method according to claim 11, characterized in that, The steps of preparing the first LED unit layer include: Provide a first substrate, on which a first LED epitaxial layer is provided; Etch the first LED epitaxial layer to form a plurality of first LED units; Form a first passivation layer, which covers the surface of the etched first LED epitaxial layer and exposes partial surfaces of a plurality of the first LED units on the side away from the first substrate.

13. The preparation method according to claim 12, characterized in that, The steps of preparing the first LED unit layer further include: Form a first electrode layer on the side of the first passivation layer away from the first LED unit, the first electrode layer surrounds the side surfaces and the side away from the first substrate of the first LED unit, and the first electrode layer also covers the surface of the area of the first LED unit on the side away from the first substrate and not covered by the first passivation layer; Form a planarizing layer, which covers the first passivation layer and the first electrode layer; Form a first conductive bump and a conductive column, one end of the first conductive bump is connected to the first electrode layer, and the other end vertically extends to the surface of the planarizing layer on the side away from the first substrate; the conductive column vertically penetrates through the planarizing layer and the first passivation layer.

14. The preparation method according to claim 13, characterized in that, The substrate includes a plurality of first contacts, and the steps of bonding the first LED unit layer onto the substrate include: Bond the planarizing layer to the substrate, and bond and electrically connect the first conductive bump and the conductive column to the corresponding first contacts; Remove the first substrate and part of the first LED epitaxial layer until the surface of the first passivation layer is exposed, so that the surfaces of the first passivation layer, the first LED unit and the conductive column on the side away from the substrate are flush.

15. The preparation method according to claim 11, characterized in that, The steps of preparing the second LED unit layer include: Provide a second substrate, on which a second LED epitaxial layer is provided; Etch the second LED epitaxial layer to form a plurality of second LED units; Form a second passivation layer, which covers the surface of the etched second LED epitaxial layer and exposes partial surfaces of a plurality of the second LED units on the side away from the second substrate. Form a second electrode layer on the side of the second passivation layer away from the second LED unit, the second electrode layer surrounds the side surfaces and the side away from the second substrate of the second LED unit, and the second electrode layer covers the surface of the area of the second LED unit on the side away from the second substrate and not covered by the second passivation layer; Form a planarizing layer, which covers the second passivation layer and the second electrode layer; Form a second conductive bump on the planarizing layer, one end of the second conductive bump is electrically connected to the second electrode layer, and the other end vertically extends to the surface of the planarizing layer on the side away from the second substrate.

16. The preparation method according to claim 15, characterized in that, The micro light-emitting diode display further includes conductive posts, and the step of bonding the second LED unit layer to the first LED unit layer includes: Bonding the planarization layer to the first passivation layer, and bonding and electrically connecting the second conductive protrusion to one end of the conductive post facing away from the substrate; Removing the second substrate and part of the second LED epitaxial layer until the surface of the second passivation layer is exposed, so that the surface of the second passivation layer is flush with the surface of the second LED unit facing away from the substrate side.

17. The preparation method according to claim 11, characterized in that, After the step of bonding the second LED unit layer to the first LED unit layer, the manufacturing method further includes: Etching the second LED unit layer to expose the surface of the first LED unit facing away from the substrate side; Forming a common electrode layer, the common electrode layer at least covers the surfaces of the first LED unit and the second LED unit facing away from the substrate side, and the common electrode layer is electrically connected to the second contact of the substrate.

18. The preparation method according to claim 17, wherein It further includes: Forming a protective layer, the protective layer at least covers the common electrode layer; Forming a color conversion unit on the protective layer, the color conversion unit is located above part of the first LED unit or part of the second LED unit.

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