CN117352532A

CN117352532A - MICRO LED display panel, manufacturing method thereof and display device

Info

Publication number: CN117352532A
Application number: CN202311339511.1A
Authority: CN
Inventors: 丁娜
Original assignee: Shanghai Xianyao Display Technology Co ltd
Current assignee: Shanghai Xianyao Display Technology Co ltd
Priority date: 2023-10-16
Filing date: 2023-10-16
Publication date: 2024-01-05

Abstract

The application provides a Micro LED display panel and a manufacturing method thereof, wherein the manufacturing method of the display panel comprises the following steps: forming a Micro LED array on one side of a driving backboard, wherein the Micro LED array comprises a plurality of Micro LED units; forming a plurality of pixel isolation structures on one side, away from the driving backboard, above the Micro LED array, wherein the pixel isolation structures form a plurality of filling spaces above the light emitting areas of the corresponding Micro LED units; and filling the filling space with a wavelength conversion structure, wherein at least one part of the wavelength conversion structure is positioned on a light propagation path emitted by the Micro LED unit, and the wavelength conversion structure can change the wavelength of light emitted by the Micro LED unit so as to change the color of the light emitted by the Micro LED. In some examples of the application, a quantum dot structure is arranged on a light emitting path of a Micro LED pixel, the quantum dot structure can change the color of light emitted by the LED pixel, and different quantum dot structures are arranged at different positions of a Micro LED display panel, so that full-color display can be realized, and meanwhile, the process difficulty and cost are reduced.

Description

MICRO LED display panel, manufacturing method thereof and display device

Technical Field

The invention relates to the field of Micro LEDs, and further relates to a Micro LED display panel, a manufacturing method thereof and a display device.

Background

Micro LEDs (Micro Light Emitting Diode) are also known as Micro light emitting diodes. The Micro LED display panel is provided with a high-density integrated LED array, the distance between LED pixels in the array is 10 microns, and each LED pixel can emit light.

Generally, each LED pixel of a Micro LED can emit only one color of light, and thus a conventional Micro LED panel is generally a single color panel. For example, a red light Micro LED panel capable of emitting only red light, a green light Micro LED panel capable of emitting only green light, and a blue light Micro LED panel capable of emitting only blue light. With the increasing imaging demands of people, single-color Micro LED panels have not been able to meet various consumer demands, and thus full-color (RGB) Micro LED panels have been developed.

Currently, in order to realize a color display scheme, it is common practice to simultaneously prepare red, green and blue LED pixels on a wafer, that is, to vertically stack the red, green and blue LED pixels. The existing full-color Micro LED structure can achieve the effect of color display, but has the advantages of high process difficulty, high process cost and low production efficiency.

In recent years, the quantum dot color conversion technology is applied to full-color display of a Micro LED display screen, and has a plurality of advantages compared with the technical scheme of vertically stacking a plurality of LEDs, but how to combine quantum dot particles with the Micro LED display screen structure is a problem to be solved in further development.

Disclosure of Invention

In order to solve one or more of the above technical problems, the present invention provides a Micro LED display panel and a manufacturing method thereof, wherein a pixel isolation structure is disposed between adjacent Micro LEDs above a Micro LED unit, and the pixel isolation structure forms a filling space above the Micro LED unit for filling a wavelength conversion structure.

The quantum dot structure is arranged on the light-emitting path of the Micro LED pixel, the quantum dot structure can change the color of light emitted by the LED pixel, and the process difficulty and cost can be reduced while full-color display can be realized by arranging different quantum dot structures at different positions of the Micro LED display panel.

An aspect of the present application provides a method for manufacturing a Micro LED display panel, including: forming a Micro LED array on one side of a driving backboard, wherein the Micro LED array comprises a plurality of Micro LED units; forming a plurality of pixel isolation structures on one side, away from the driving backboard, above the Micro LED array, wherein the pixel isolation structures form a plurality of filling spaces above the light emitting areas of the corresponding Micro LED units; and filling the filling space with a wavelength conversion structure, wherein at least one part of the wavelength conversion structure is positioned on a light propagation path emitted by the Micro LED unit, and the wavelength conversion structure can change the wavelength of light emitted by the Micro LED unit so as to change the color of the light emitted by the Micro LED.

Another aspect of the present application provides a Micro LED display panel, comprising: a drive back plate; and a Micro LED array disposed at one side of the driving back plate, and including: a plurality of Micro LED units; a pixel isolation structure which is arranged above the Micro LED array and far away from one side of the driving backboard, and forms a plurality of filling spaces above the light-emitting areas of a plurality of corresponding Micro LED units; and a wavelength conversion structure located within the filling space and at least a portion of which is located on a propagation path of light emitted from the Micro LED unit, wherein the wavelength conversion structure is capable of changing a wavelength of light emitted from the Micro LED unit to change a color of light emitted from the Micro LED.

Another aspect of the present application provides a display device comprising a Micro LED display panel according to any one of the above.

According to the MICRO LED display panel and the manufacturing method thereof, a pixel isolation structure can be arranged between adjacent MICRO LEDs corresponding to the upper part of the MICRO LED unit, and the pixel isolation structure forms a filling space above the MICRO LED unit for filling the wavelength conversion structure. On the other hand, a quantum dot structure can be arranged on the light-emitting path of the Micro LED pixel, and the quantum dot structure can change the color of light emitted by the LED pixel. Therefore, by arranging different quantum dot structures at different positions of the Micro LED display panel, full-color display can be realized, and meanwhile, the process difficulty and the cost are reduced. It should be noted that, in this application, the various aspects do not necessarily require that the above technical effects be completely achieved, and each aspect constitutes a contribution to the art by the technical effects that can be achieved by at least one of the technical problems that it can solve.

Drawings

The foregoing and other objects, features and advantages of the disclosure will be apparent from the following more particular descriptions of exemplary embodiments of the disclosure as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts throughout exemplary embodiments of the disclosure.

FIG. 1 is a schematic top view of a Micro LED display panel according to an embodiment of the present application;

FIG. 2 is a schematic cross-sectional view of the embodiment of FIG. 1 of the present application with two adjacent Micro LED units arranged side by side;

FIG. 3 is a schematic cross-sectional view of a variant embodiment of the embodiment of FIG. 1 of the present application in which two adjacent Micro LED units are arranged side by side;

FIG. 4 is a flow chart of a method of manufacturing a Micro LED display panel according to an embodiment of the present application;

FIG. 5 is a sub-flowchart of a method of manufacturing a Micro LED display panel according to an embodiment of the present application;

FIGS. 6a-i are schematic structural diagrams of a manufacturing process of a Micro LED display panel according to an embodiment of the present application;

FIG. 7 is a sub-flowchart of a method of manufacturing a Micro LED display panel according to an embodiment of the present application;

FIG. 8 is a sub-flowchart of a method of manufacturing a Micro LED display panel according to an embodiment of the present application;

fig. 9 is a schematic top view of a Micro LED display panel according to an embodiment of the present application.

Detailed Description

Preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

Some embodiments of the present application provide a Micro LED display panel 100.

Fig. 1 shows a schematic top view of a Micro LED display panel 100 provided in the present application. The Micro LED display panel 100 provided herein includes a Micro LED array 10 and a driving back plate 20. The Micro LED array 10 is disposed on one side of the driving back plate 20 and forms an image display area, and the driving back plate 20 is disposed on the back surface (i.e., the side where light is not desired to be transmitted) of the Micro LED array 10. The area of the driving back plate 20 where the Micro LED array 10 is not provided is a non-functional area. The Micro LED array 10 includes a plurality of Micro LED units 11 (which can also be referred to as pixels). The drive back plate 20 is configured to control the plurality of Micro LED units 11 of the Micro LED array 10. For example, the on/off of the Micro LED unit 11 or the light emission luminance of the Micro LED unit 11 is controlled.

Fig. 2 shows a schematic structural diagram of two adjacent Micro LED units 11 in the Micro LED display panel 100 provided by the present application, which are arranged in parallel. It should be understood that the Micro LED array 10 may include several sets of adjacent Micro LED units 11 in a row or column, and that the two illustrated adjacent relationships may extend up to the edge of the Micro LED array 10. Referring to fig. 2, the micro LED array 10 further includes a plurality of pixel isolation structures 12. The pixel isolation structure 12 is disposed on a side of the Micro LED array 10 away from the driving back plate 20, and the pixel isolation structure 12 may be considered to be disposed above the Micro LED array 10 in terms of the layout of the Micro LED display panel 100 as shown in fig. 2, which are equivalent in the context of the present application. The pixel isolation structure 12 is disposed around the light emitting region of the Micro LED units 11, and more particularly, may be disposed between the light emitting regions of two adjacent Micro LED units 11, thereby separating propagation paths of light emitted from the two adjacent Micro LED units 11, and thus, light crosstalk between the adjacent Micro LED units 11 can be reduced to some extent. Fig. 9 shows a finer top view than fig. 1, in which the general positional relationship of the pixel isolation structure 12 and the Micro LED unit 11 in the Micro LED array 10 is shown. As can be seen more in fig. 9, each Micro LED unit 11 in the Micro LED array 10 has a pixel isolation structure 12 surrounding the periphery thereof, so that the problem of light crosstalk between adjacent Micro LED units 11 can be alleviated.

Returning to fig. 2, in some embodiments, the pixel isolation structure 12 includes a partition wall 121 and a first reflective layer 122. The partition wall 121 is disposed at a side of the Micro LED array 10 remote from the driving back plate 20, and is disposed around the light emitting region of the Micro LED unit 11. The first reflective layer 122 is disposed on the surface of the partition wall 121, and the first reflective layer 122 can reflect light emitted by the Micro LED unit 11. In some embodiments, the partition wall 121 comprises a light absorbing material. In some embodiments, the constituent material of the first reflective layer 122 includes a metal.

Referring to fig. 2, the pixel isolation structure 12 forms a filling space 13 above the Micro LED unit 11. The Micro LED array 10 further comprises a wavelength converting structure 14, the wavelength converting structure 14 is disposed in the filling space 13, and at least a portion of the wavelength converting structure 14 is located on a propagation path of light emitted by the Micro LED unit 11, and the wavelength converting structure 14 is capable of changing a wavelength of the light emitted by the Micro LED unit 11 to change a color of the light emitted by the Micro LED unit 11.

In some embodiments, the wavelength conversion structure 14 includes Quantum Dot (Quantum Dot) particles 141 and a photoresist 142, the Quantum Dot particles 141 and the photoresist 142 are mixed and filled in the filling space 13, and the Quantum Dot particles 141 are located on a propagation path of light emitted from the Micro LED unit 11. The quantum dot particles 141 are nano-scale semiconductors, and when a certain electric field or light pressure is applied to the quantum dot particles 141, the quantum dot particles 141 emit light of a specific wavelength (i.e., frequency). Under the same electric field or light pressure, the wavelength (i.e., frequency) of the light emitted from the quantum dot particles 141 will vary with the size of the quantum dot particles 141, so that the color of the light emitted from the quantum dot particles 141 can be controlled by controlling the size of the quantum dot particles 141. In the Micro LED display panel 100 provided in the present application, when the light emitted by the Micro LED unit 11 irradiates the quantum dot particles 141, a certain light pressure is applied to the quantum dot particles 141, so that the quantum dot particles 141 emit light with a specific wavelength (i.e. frequency). The pixel isolation structure 12 can further isolate light emitted from the adjacent wavelength converting structure 14, reducing optical crosstalk of the adjacent Micro LED units 11.

In some embodiments, the Micro LED array 10 includes at least two light emitting regions, and the filling spaces 13 corresponding to the different types of light emitting regions are filled with quantum dot particles 141 of different sizes, so that the Micro LED array 10 can emit light of at least two different colors. Each light emitting region has a plurality of Micro LED units 11, and the Micro LED units 11 of different kinds of light emitting regions are staggered with each other. The staggered arrangement here means that the Micro LED units 11 in the different kinds of light emitting areas are not adjacent, and the total number of Micro LED units 11 in the respective kinds of light emitting areas is approximately equal. More specifically, the Micro LED units 11 of the respective kinds of light emitting regions may be sequentially spaced apart.

In some embodiments, the at least two light emitting regions of the Micro LED array 10 may specifically be three light emitting regions (a first light emitting region, a second light emitting region, and a third light emitting region), which respectively correspond to the three different sizes of the quantum dot particles 141. Specifically, the first light emitting region emits red light, and the corresponding quantum dot particles 141 range in size from 6nm to 10nm; the second light emitting region emits green light, and the corresponding quantum dot particles 141 range in size from 3nm to 5nm; and the third light emitting region emits blue light, and the corresponding quantum dot particles 141 range in size from 1nm to 3nm.

Referring to fig. 2, the Micro LED display panel 100 provided herein further includes a moisture blocking layer 15. The moisture blocking layer 15 is disposed on a side of the wavelength conversion structure 14 away from the driving back plate 20, and the moisture blocking layer 15 covers the wavelength conversion structure 14 and the pixel isolation structure 12. The moisture barrier layer 15 can isolate the wavelength converting structure 14 located in the filling space 13 from the external environment, avoiding the wavelength converting structure 14 from contacting moisture, oxygen, etc. in the external environment.

Referring to fig. 2, the Micro LED display panel 100 provided herein further includes a filter layer 16. The filter layer 16 is disposed on a side of the moisture blocking layer 15 away from the driving back plate 20, and is located on a light propagation path emitted by the Micro LED unit 11. In some embodiments, the filter layer 16 may be continuously disposed on the surface of the moisture barrier layer 15. The filter layer 16 is capable of filtering light emitted from the Micro LED unit 11, and light emitted from the quantum dot particles 141 is capable of exiting through the filter layer 16. In some embodiments, the Micro LED unit 11 is capable of emitting UV (ultra violet) light, and accordingly, the filter layer 16 is a UV filter layer. In some embodiments, the filter layer 16 may also be disposed on a side of the moisture barrier layer 15 near the driving back plate 20.

Referring to fig. 2, the micro LED unit 11 includes a first semiconductor layer 111, a light emitting layer 112, and a second semiconductor layer 113 disposed on a driving back plate 20 and stacked in this order from top to bottom. The first semiconductor layer 111, the light-emitting layer 112, and the second semiconductor layer 113 form a light-emitting mesa, and the light-emitting layer 112 can emit light when the first semiconductor 111 and the second semiconductor 113 are energized. In some embodiments, both the top and bottom surfaces of the light emitting mesa are rounded and the diameter of the bottom surface of the light emitting mesa (the surface closest to the drive backplate 20) is smaller than the diameter of the top surface (the surface farther from the drive backplate 20). In the context of the present application, the top and bottom of the light emitting mesa (or Micro LED unit 11) are both oriented as they appear in their final configuration (e.g., the state shown in fig. 2). During processing, the top and bottom of the light emitting mesa (or Micro LED unit 11) may be turned up and down. For ease of understanding and for unification of terminology, the top in the final form (e.g., the state shown in fig. 2) will be referred to herein as the top of the light emitting mesa (or Micro LED unit 11), and the bottom in the final form (e.g., the state shown in fig. 2) will be referred to herein as the bottom of the light emitting mesa (or Micro LED unit 11).

Referring to fig. 2, the micro LED unit 11 further includes a first conductive layer 114, a second reflective layer 115, and a metal connection 116. The first conductive layer 114 is disposed on a side of the first semiconductor layer 111 away from the second semiconductor layer 113, and is electrically connected to the first semiconductor layer 111. The second reflective layer 115 is disposed at the bottom and the outer sidewall of the light emitting mesa, and is electrically connected to the second semiconductor layer 113. The metal connection piece 116 is disposed on a side of the second reflective layer 115 away from the first conductive layer 114, and one end of the metal connection piece 116 is electrically connected to the second reflective layer 115, and the other end is electrically connected to the driving back plate 20. The second reflective layer 115 can not only electrically connect the second semiconductor layer 113 and the metal connection member 116, but also reflect light emitted from the light emitting layer 112, thereby improving the light emitting efficiency of the Micro LED unit 11.

The Micro LED unit 11 further comprises a second conductive layer 117 and a current spreading structure 118. The second conductive layer 117 is disposed on a side of the second semiconductor layer 113 remote from the first semiconductor layer 111, and is electrically connected to the second semiconductor layer 113. The current spreading structure 118 is disposed on a side of the first conductive layer 114 remote from the first semiconductor layer 111 and over the non-light emitting region between adjacent Micro LED units 11. The current spreading structure 118 can increase current spreading between adjacent Micro LED units 11, thereby reducing resistance between adjacent Micro LED units 11 and reducing loss. In some embodiments, the material of the current spreading structure 118 is a metal, including one or more of Al, au, rh, ag, cr, ti, pt, sn, cu, auSn, tiW, etc.

With continued reference to fig. 2, further, the Micro LED unit 11 further includes a first passivation layer 1191 and a second passivation layer 1192. The first passivation layer 1191 is disposed on the bottom and the sidewall of the light emitting mesa, and has an opening corresponding to the second conductive layer 117, and at least a portion of the second reflective layer 115 is disposed in the opening and electrically connected to the second conductive layer 117. The second passivation layer 1192 is disposed on the side of the first conductive layer 114 and the current spreading structure 118 away from the first semiconductor layer 111, and isolates the electrical connection between the first conductive layer 114 and the pixel isolation structure 12. The first passivation layer 1191 and the second passivation layer 1192 are each made of an insulating material including, but not limited to, siO ₂ SiN or Al ₂ O ₃ Etc.

With continued reference to fig. 2, in some embodiments, the second reflective layer 115 includes a main reflective layer 1151 and a side reflective layer 1152. The main reflective layer 1151 is located between the metal connection member 116 and the second conductive layer 117, the side reflective layer 1152 is located on the outer sidewall of the light emitting mesa, and one end of the side reflective layer 1152 is connected to the main reflective layer 1151, and the other end extends to the side of the light emitting layer 112. The main reflective layer 1151 can reflect light at the bottom of the light emitting mesa, the side reflective layer 1152 can reflect light at the side of the light emitting mesa, and the main reflective layer 1151 and the side reflective layer 1152 cooperate with each other to improve the light reflection effect.

With continued reference to fig. 2, in some embodiments, a side of the second reflective layer 115 remote from the second semiconductor layer 113 has a groove 1150, and an end of the metal connection 116 remote from the driving backplate 20 is disposed in the groove 1150. One end of the metal connection piece 116 far away from the driving back plate 20 is disposed in the groove 1150, so that the contact area between the metal connection piece 116 and the second reflective layer 115 can be increased, and the current expansion can be improved.

In some embodiments, the Micro LED unit 11 further includes an insulating layer 110. The insulating layer 110 is disposed between the driving back plate 20 and the first passivation layer 1191, and surrounds the second reflective layer 115 and the metal connection 116. In some embodiments, the metal connector 116 includes a peripheral metal layer 1161 and metal pillars 1162. A portion of the peripheral metal layer 1161 is located between the metal pillars 1162 and the insulating layer 110, and another portion of the peripheral metal layer 1161 is disposed on a side of the insulating layer 110 near the driving back plate 20, for bonding with a metal layer on the driving back plate 20. The material of the peripheral metal layer 1161 may be titanium copper (TiCu), and the material of the metal pillars 1162 may be copper (Cu), wherein the peripheral metal layer 1161 is a seed layer, thereby facilitating formation of the metal pillars 1162 through an electroplating process.

In some embodiments, the drive backplate 20 is a TFT (Thin Film Transistor) plate or IC (Integrated Circuit) plate.

Fig. 3 is another embodiment of a schematic cross-sectional structure of two adjacent Micro LED units arranged in parallel according to the embodiment shown in fig. 1 of the present application. Referring to fig. 3, the side of the wavelength converting structure 14 remote from the driving back plate 20 is arranged protruding outwards. In some embodiments, the outwardly convex disposed wavelength converting structure 14 has the effect of collimating light. In some embodiments, the side of the wavelength converting structure 14 remote from the drive backplate 20 is outwardly convex in a hemispherical shape. Accordingly, the moisture barrier layer 15, the filter layer 16 will be arranged to protrude outwards together with the wavelength converting structure 14. In addition, the rest of the embodiment shown in fig. 3 may refer to the embodiment shown in fig. 2, and will not be described herein.

Referring to fig. 2, in some embodiments, the thickness H1 of the wavelength converting structure 14 ranges from 1nm to 15nm. In some embodiments, the thickness H2 of one light emitting mesa is in the range of 0.3 μm to 3.5 μm and the bottom diameter is in the range of 0.5 μm to 50 μm. The thickness H3 of the Micro LED unit 11 ranges from 1 μm to 10 μm and the diameter ranges from 2 μm to 200 μm. The Micro LED display panel 100 has a length ranging from 500 μm to 50000 μm, and the Micro LED array 10 composed of the Micro LED units 11 in the display panel has a resolution of one of 320×240, 640×480, 1920×1080, 2560×1440. In some embodiments, the resolution of the array of Micro LEDs in the display panel can also be other values.

Some embodiments of the present application also provide a method for manufacturing a Micro LED display panel.

Fig. 4 is a flow chart showing steps of a method for manufacturing a Micro LED display panel according to an embodiment of the present application, fig. 5 is a sub-flow chart of a method for manufacturing a Micro LED display panel according to an embodiment of the present application, and fig. 6a-i are schematic structural diagrams of a flow chart of a method for manufacturing a Micro LED display panel according to an embodiment of the present application. For purposes of illustration only and not to limit the disclosed embodiments, fig. 6a-i only show the formation of two adjacent Micro LED units. It is contemplated that the illustrated process may be used to fabricate Micro LED arrays comprising more than two Micro LED units. Referring to fig. 4 and 6a-i, the method of fabrication comprises steps S1 to S3 and optionally steps S4 to S5. Methods of manufacturing Micro LED display panels according to some embodiments of the present application will be described below in conjunction with fig. 4, 5, and 6 a-i.

Before describing the methods shown in fig. 4 and 5, the flow of manufacturing a Micro LED display panel will be described herein in more detail by way of example in connection with fig. 6 a-i. It is noted that this detailed example is merely for convenience in understanding the general principles of the present application and should not be construed as constituting additional limitations to other embodiments of the present application. In the following examples, fig. 6a-i will also be described in terms of individual discrete processes in the corresponding method steps.

As shown in fig. 6a, a single provided epitaxial wafer 30 may first be provided. The epitaxial wafer 30 includes a substrate 18, a U-GaN layer 19, a first semiconductor layer 111, a light-emitting layer 112, and a second semiconductor layer 113, which are stacked in this order from bottom to top (in the state shown in fig. 6 a). Subsequently, the second conductive layer 117 may be formed on the second semiconductor layer 113 of the epitaxial wafer 30 through a deposition process or the like.

Turning to fig. 6b, the second conductive layer 117, the second semiconductor layer 113 and the light emitting layer 112 are etched to form a plurality of light emitting mesas. Subsequently, a first passivation layer 1191 is formed on the outer side of the light emitting mesa, on the side of the first semiconductor layer 111 remote from the substrate 18, wherein the first passivation layer 1191 has openings at positions corresponding to the bottom surface (bottom surface in the final state, top surface in fig. 6 b) of the light emitting mesa.

With continued reference to fig. 6b, in a next process step, a second reflective layer 115 may be formed on the bottom and sidewalls of the light emitting mesa. Specifically, the main reflective layers 1151 may be formed on the bottom of the light emitting mesa (i.e., the side of the second conductive layer 117 away from the substrate 18), and the side reflective layers 1152 may be formed on the outer sidewalls of the light emitting mesa, respectively. One end of the side reflection layer 1152 is connected to the main reflection layer 1151, and the other end extends to the side of the light emitting layer 112. As shown in fig. 6b, the side reflective layer 1152 may not be flush with the main reflective layer 1151 at the location of attachment to the main reflective layer 1151, but rather slightly higher than the main reflective layer 1151, such that the illustrated recess 1150 may be formed.

Turning next to fig. 6c, to encapsulate some of the elements of Micro LED array 10 and provide insulation to the outside, an insulating layer 110 may be deposited on the side of the epitaxial wafer away from substrate 18, such that insulating layer 110 covers the light emitting mesa and second reflective layer 115 (including main reflective layer 1151 and side reflective layer 1152).

With continued reference to fig. 6c, insulating layer 110 will then be etched to the main reflective layer 1151 to form insulating layer holes 1100 at locations corresponding to the main reflective layer 1151 (specifically, directly above the main reflective layer 1151 shown in fig. 6 c). As such, the insulating layer hole 1100 will extend from the recess 1150 all the way to the surface of the insulating layer 110.

Subsequently, a peripheral metal layer 1161 of the metal connector 116 is formed on the side of the insulating layer 110 remote from the substrate 18 and on the inner side wall of the insulating layer hole 1100. The peripheral metal layer 1161 may be electrically connected to the main reflective layer 1151 and led out to the surface of the insulating layer 110. Then, metal is injected into the insulating layer hole 1100 through an electroplating process to form a metal pillar 1162 of the metal connection 116, and the metal pillar 1162 may also be electrically connected to the main reflective layer 1151 and led out to the surface of the insulating layer 110. Thus, one columnar metal connection 116 including two metal layers, electrically connected to the main reflection layer 1151, and led out to the surface of the insulating layer 110 can be formed. The peripheral metal layer 1161 deposited on the surface of the insulating layer 110 may be removed later by bonding so that the surface of the insulating layer 110 abuts against the driving backplate 20 described later.

Turning to fig. 6d, a driving back plate 20 may be further provided, and a bonding metal layer (not shown) may be formed on one side of the driving back plate 20. Proceeding to this step will reverse the epitaxial wafer 30 with the elements thereon, thereby facilitating bonding to the drive backplate 20. The substrate 18 may be removed after bonding the peripheral metal layer 1161 to the bond metal layer. In some embodiments, the U-GaN layer 19 is also removed after the substrate 18 is removed.

Turning to fig. 6e, a next process will form a first conductive layer 114 on the side of the first semiconductor layer 111 remote from the second semiconductor layer 113. Thus, the first conductive layer 114 may electrically connect the first semiconductor layers 111 of the respective Micro LED units 11 in the finally formed Micro LED array 10.

Then, a predetermined amount of metal may be injected between the side of the first conductive layer 114 away from the second semiconductor layer 113 and the corresponding adjacent light emitting mesa to form the current spreading structure 118. Specifically, the current spreading structure 118 may be formed directly above the region between the two light emitting mesas.

As shown in fig. 6f, a second passivation layer 1192 may be further formed on the surface of the first conductive layer 114 and the current spreading structure 118, thereby providing external insulation to the elements under the second passivation layer 1192.

The spacer walls 121 may then be formed by filling a predetermined height of light-insulating material at predetermined positions above the Micro LED array 10. The partition wall 121 is disposed over the non-light emitting region between adjacent Micro LED units 11. A metal material is coated on the outer side of the partition wall 121 to form a first reflective layer 122. As shown in fig. 6g, a partition wall 121 may be disposed over the current spreading structure 118 and enclose the current spreading structure 118. Thereby, the pixel isolation structure 12 including the isolation wall 121 and the first reflective layer 122 may be constructed between adjacent Micro LED units 11.

As shown in fig. 6h, a filling space 13 is formed above the Micro LED unit 11 at a portion of the pixel isolation structure 12 higher than the Micro LED unit 11. Turning again to fig. 6h, the filling space 13 may then be filled with a wavelength converting structure 14 (comprising quantum dot particles 141 and photoresist 142), the wavelength converting structure 14 being located in the path of light rays emitted by the Micro LED unit 11.

Finally, as shown in fig. 6i, the moisture blocking layer 15 and the filter layer 16 are sequentially formed from bottom to top on the side of the wavelength conversion structure 14 away from the driving back plate 20. In some embodiments, the filter layer 16 may be formed first, and then the moisture blocking layer 15 may be formed on the filter layer 16.

The flow of manufacturing a Micro LED display panel is generally described above in connection with fig. 6 a-i. In addition, fig. 4 shows a step flowchart of a method for manufacturing a Micro LED display panel according to an embodiment of the present application, specifically including the following steps S1 to S3 and optional steps S4 to S5.

In step S1, a Micro LED array 10 is formed on one side of the driving back plate 20, and the Micro LED array 10 includes a plurality of Micro LED units 11. As shown in fig. 6d, a plurality of Micro LED units 11 are formed at one side of the driving back plate 20 provided, wherein the driving back plate 20 is configured to control the Micro LED array 10. In some embodiments, the drive backplate 20 is a TFT (Thin Film Transistor) plate or IC (Integrated Circuit) plate.

In step S2, a plurality of pixel isolation structures 12 (including the isolation wall 121 and the first reflective layer 122 on the surface thereof) as shown in fig. 6g are formed over the Micro LED array 10, and the pixel isolation structures 12 form a plurality of filling spaces 13 over the corresponding plurality of Micro LED units 11.

In step S3, the filling space 13 is filled with the wavelength converting structure 14 as shown in fig. 6h, at least a portion of the wavelength converting structure 14 is located on the light propagation path emitted by the Micro LED unit 11, and the wavelength converting structure 14 is capable of changing the wavelength of the light emitted by the Micro LED unit 11 to change the color of the light emitted by the Micro LED unit 11.

In some embodiments, the wavelength conversion structure 14 includes Quantum Dot (Quantum Dot) particles 141 and a photoresist 142, the Quantum Dot particles 141 and the photoresist 142 are mixed and filled in the filling space 13, and the Quantum Dot particles 141 are located on a propagation path of light emitted from the Micro LED unit 11. The quantum dot particles 141 are nano-scale semiconductors, when a certain electric field or light pressure is applied to the quantum dot particles 141, the quantum dot particles 141 emit light of a specific wavelength (i.e., frequency), and the wavelength (i.e., frequency) of the emitted light varies with the change of the size of the quantum dot particles 141, and the color of the emitted light can be controlled by controlling the size of the quantum dot particles 141 under the same electric field or light pressure. In the Micro LED display panel provided in the present application, when the light emitted by the Micro LED unit 11 irradiates the quantum dot particles 141, a certain light pressure is applied to the quantum dot particles 141, so that the quantum dot particles 141 emit light with a specific wavelength (i.e. frequency).

Fig. 7 is a sub-flowchart of a method of manufacturing a Micro LED display panel according to an embodiment of the present application. In some embodiments, in the step of filling the wavelength conversion structure 14 into the filling space 13 in step S3 described above, as shown in fig. 7, steps S31 to S32 are further included.

In step S31, the plurality of Micro LED units 11 of the Micro LED array 10 are divided into at least two kinds of light emitting areas, and the Micro LED units 11 of different kinds of light emitting areas are staggered with each other.

In step S32, the filling space 13 of the different kinds of light emitting regions is filled with quantum dot particles 141 of different sizes.

Returning to fig. 4, in some embodiments, after step S3 described above, steps S4 and S5 are further included.

In step S4, a moisture blocking layer 15 is formed on a side of the wavelength converting structure 14 away from the driving backplate 20, such that the moisture blocking layer 15 covers the wavelength converting structure 14 and the pixel isolation structure 12.

In step S5, a filter layer 16 is formed on a side of the moisture blocking layer 15 away from the wavelength conversion structure 14, the filter layer 16 is disposed on the light propagation path of the Micro LED unit 11, and the filter layer 16 can filter the light of the Micro LED unit 11. In some embodiments, micro LED units 11 are capable of emitting UV light, and accordingly, filter layer 16 is a UV filter layer. The UV filter layer is capable of filtering UV light emitted from the Micro LED unit 11.

Fig. 8 is a sub-flowchart of a method of manufacturing a Micro LED display panel according to an embodiment of the present application. In some embodiments, in the step of forming a plurality of pixel isolation structures 12 above the Micro LED array 10 at step S2 described above, as shown in fig. 8, steps S21 and S22 are further included.

In step S21, a light isolation material of a predetermined height is filled at a predetermined position above the Micro LED array 10 to form the isolation wall 121. The partition wall 121 is disposed over the non-light emitting region between adjacent Micro LED units 11.

In step S22, a layer of metal material is plated on the outer side of the partition wall 121 to form the first reflective layer 122.

Referring to fig. 5, in some embodiments, in the step of forming the Micro LED array 10 at one side of the driving back plate 20 at step S1 described above, steps S11 to S112 are further included.

In step S11, an epitaxial wafer 30 is provided, and the epitaxial wafer 30 includes a substrate 18, a first semiconductor layer 111, a light-emitting layer 112, and a second semiconductor layer 113, which are stacked in this order from bottom to top. In some embodiments a U-GaN layer 19 is provided between the substrate 18 and the first semiconductor layer 111. The substrate 18 having the U-GaN layer 19, which is also called a GaN substrate, can serve as a support for the first semiconductor layer 111, the light emitting layer 112, and the second semiconductor layer 113 on the GaN substrate.

In step S12, a second conductive layer 117 is provided on a side of the second semiconductor layer 113 remote from the substrate 18.

In step S13, the second conductive layer 117, the second semiconductor layer 113, and the light emitting layer 112 are etched to form a plurality of light emitting mesas. Specifically, the epitaxial wafer may be etched along a preset path to divide the epitaxial wafer into a plurality of regions; the second conductive layer 117, the second semiconductor layer 113, and the light emitting layer 112 are then etched in each region, respectively, to form a plurality of light emitting mesas.

In step S14, a first passivation layer 1191 is formed on the outer side of the light emitting mesa and on the side of the first semiconductor layer 111 away from the substrate 18, wherein the first passivation layer 1191 has an opening at a position corresponding to the bottom surface (in terms of the final state) of the light emitting mesa.

In step S15, a second reflective layer 115 is formed on the bottom and sidewalls of the light emitting mesa.

In step S16, an insulating layer 110 is deposited on the side of the epitaxial wafer away from the substrate 18, such that the insulating layer 110 covers the light emitting mesa and the second reflective layer 115.

In step S17, the insulating layer 110 is etched to the second reflective layer 115 at a position corresponding to the second reflective layer 115 to form an insulating layer hole 1100. Specifically, the insulating layer 110 may be etched directly over the main reflective layer 1151 to form an insulating layer hole 1100.

In step S18, a peripheral metal layer 1161 is formed on the side of the insulating layer 110 remote from the substrate 18 and the inner side wall of the insulating layer hole 1100.

In step S19, a metal is injected into the insulating layer hole 1100 to form a metal pillar 1162.

In step S110, the driving back plate 20 is provided, and a bonding metal layer is formed on one side of the driving back plate 20.

In step S111, the substrate 18 is removed after bonding the peripheral metal layer 1161 with the bonding metal layer. In some embodiments, the U-GaN layer 19 is removed after the substrate 18 is removed.

In step S112, a first conductive layer 114 is formed on a side of the first semiconductor layer 111 remote from the second semiconductor layer 113.

In step S113, a predetermined amount of metal is injected between the adjacent light emitting mesas on the side of the first conductive layer 114 away from the second semiconductor layer 113 to form a current spreading structure 118.

In some embodiments, in step S2, the position of the pixel isolation structure 12 corresponds to the position of the current spreading structure 118, and is disposed above the current spreading structure 118.

It should be noted that relational terms such as "first" and "second" are used herein solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Furthermore, the terms "comprising," "having," and "including," and other similar forms, are intended to be equivalent in meaning and be open ended, and that one or more items following any one of these terms are not intended to be an exhaustive list of such one or more items, or to be limited to only the one or more items listed.

As used herein, unless explicitly stated otherwise, the term "or" encompasses all possible combinations unless not possible. For example, if it is stated that a component may include a or B, the component may include a, or B, or a and B unless explicitly stated otherwise or not possible. As a second example, if it is stated that a component may include A, B or C, the component may include a, or B, or C, or a and B, or a and C, or B and C, or a and B and C, unless explicitly stated otherwise or not possible.

In the foregoing specification, embodiments have been described with reference to numerous specific details that may vary from implementation to implementation. Certain variations and modifications may be made to the described embodiments. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the present application disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims. The order of steps shown in the figures is also intended to be illustrative only and is not intended to be limited to any particular order of steps. Thus, those skilled in the art will appreciate that the steps may be performed in a different order while achieving the same method.

In the drawings and specification, exemplary embodiments have been disclosed. However, many variations and modifications may be made to these embodiments. Accordingly, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

1. A method for manufacturing a Micro LED display panel, comprising:

forming a Micro LED array on one side of a driving backboard, wherein the Micro LED array comprises a plurality of Micro LED units;

Forming a plurality of pixel isolation structures on one side, away from the driving backboard, above the Micro LED array, wherein the pixel isolation structures form a plurality of filling spaces above the light emitting areas of the corresponding Micro LED units; and

and filling the filling space with a wavelength conversion structure, wherein at least one part of the wavelength conversion structure is positioned on a light propagation path emitted by the Micro LED unit, and the wavelength conversion structure can change the wavelength of light emitted by the Micro LED unit.

2. The method as recited in claim 1, further comprising:

and a water vapor blocking layer and a light filtering layer are formed on one side, far away from the driving backboard, of the Micro LED array, wherein the water vapor blocking layer covers the wavelength conversion structure and the pixel isolation structure, and the light filtering layer is positioned on a light propagation path emitted by the Micro LED unit and can filter light emitted by the Micro LED unit.

3. The method according to claim 1 or 2, characterized in that the Micro LED lighting unit is capable of emitting UV light.

4. The method of claim 1 or 2, wherein the wavelength converting structure comprises quantum dot particles and a photoresist.

5. The method of claim 4, wherein filling the filling space with wavelength converting structures comprises:

dividing the plurality of Micro LED units of the Micro LED array into at least two light-emitting areas, wherein the Micro LED units corresponding to different types of light-emitting areas are arranged in a staggered manner; and

and filling quantum dot particles with different sizes into the filling spaces of the different types of light-emitting areas.

6. The method of claim 1 or 2, wherein the step of forming a plurality of pixel isolation structures on a side of the Micro LED array above and away from the drive back plate, further comprises:

filling a light isolation material with a preset height at a preset position above the Micro LED array to form a isolation wall; and

and plating a layer of metal material on the outer side of the isolation wall to form a first reflecting layer.

7. The method of claim 6, wherein the step of forming a Micro LED array on one side of the drive back plate further comprises:

providing an epitaxial wafer, wherein the epitaxial wafer comprises a substrate, a first semiconductor layer, a light-emitting layer and a second semiconductor layer which are sequentially stacked from bottom to top;

Providing a second conductive layer on a side of the second semiconductor layer away from the substrate;

etching the second conductive layer, the second semiconductor layer and the light-emitting layer to form a plurality of light-emitting mesas;

forming a first passivation layer on the outer side surface of the light-emitting table surface and on one side, far away from the substrate, of the first semiconductor layer, wherein the first passivation layer is provided with an opening at a position corresponding to the bottom surface of the light-emitting table surface;

forming a second reflecting layer on the bottom and the side wall of the light-emitting table top;

depositing an insulating layer on one side of the epitaxial wafer far away from the substrate, wherein the insulating layer covers the first passivation layer and the second reflecting layer;

etching the insulating layer at a position corresponding to the second reflecting layer until an insulating layer hole is formed in the second reflecting layer;

forming a peripheral metal layer on the side of the insulating layer away from the substrate and on the inner side wall of the insulating layer hole;

injecting metal into the insulating layer hole to form a metal column;

providing a driving backboard and forming a bonding metal layer on one side of the driving backboard;

bonding the peripheral metal layer and the bonding metal layer and then removing the substrate;

Forming a first conductive layer on a side of the first semiconductor layer away from the second semiconductor layer; and

and injecting a preset amount of metal between the side, away from the second semiconductor, of the first conductive layer and the corresponding adjacent light-emitting table top to form a current expansion structure.

8. The method of claim 7, wherein the step of forming a plurality of pixel isolation structures over the array of Micro LEDs further comprises: and forming the pixel isolation structure at a position corresponding to the current expansion structure.

9. The method of claim 7, wherein etching the second conductive layer, the second semiconductor layer, and the light emitting layer to form a plurality of light emitting mesas comprises:

etching the epitaxial wafer along a preset path, and dividing the epitaxial wafer into a plurality of areas; and

and etching the second conductive layer, the second semiconductor layer and the light-emitting layer in each region to form a plurality of light-emitting mesas.

10. A Micro LED display panel, comprising:

a drive back plate; and

micro LED array, micro LED array set up in one side of drive backplate to include:

a plurality of Micro LED units;

A pixel isolation structure which is arranged above the Micro LED array and far away from one side of the driving backboard, and forms a plurality of filling spaces above the light-emitting areas of a plurality of corresponding Micro LED units; and

a wavelength converting structure located within the filling space and at least a portion of which is located on a propagation path of light emitted from the Micro LED unit, wherein,

the wavelength conversion structure is capable of changing the wavelength of light emitted by the Micro LED unit.

11. The Micro LED display panel of claim 10, further comprising: and the water vapor blocking layer is arranged on one side of the Micro LED array, which is far away from the driving backboard, and covers the wavelength conversion structure and the pixel isolation structure.

12. The Micro LED display panel of claim 10, further comprising: the light filtering layer is arranged on one side, far away from the driving backboard, of the Micro LED array, and is located on a light propagation path emitted by the Micro LED unit and capable of filtering light emitted by the Micro LED unit.

13. The Micro LED display panel of claim 12, wherein the Micro LED light emitting unit is capable of emitting UV light.

14. The Micro LED display panel of any one of claims 10-12, wherein the wavelength converting structure comprises quantum dot particles and a photoresist.

15. The Micro LED display panel according to claim 14, wherein the Micro LED array comprises at least two light emitting areas, each of the light emitting areas has a plurality of Micro LED units, the Micro LED units corresponding to different kinds of the light emitting areas are staggered with each other, and quantum dot particles filled in the filling space corresponding to different kinds of the light emitting areas have different sizes.

16. The color Micro LED display panel according to claim 15, wherein the Micro LED array comprises a first light emitting region, a second light emitting region and a third light emitting region, the first light emitting region emits red light, and the size of the corresponding quantum dot particles ranges from 6nm to 10nm; the second light-emitting area emits green light, and the size range of the corresponding quantum dot particles is 3 nm-5 nm; and the third light-emitting region emits blue light, and the size range of the corresponding quantum dot particles is 1 nm-3 nm.

17. The Micro LED display panel according to any of claims 10-12, wherein the pixel isolation structure comprises a partition wall formed of a light isolation material and a first reflective layer located outside the partition wall.

18. The Micro LED display panel according to any one of claims 10-12, wherein the Micro LED unit comprises:

a first semiconductor layer, a light emitting layer and a second semiconductor layer stacked from top to bottom;

the second conductive layer, the second reflecting layer and the metal connecting piece are sequentially stacked on one side, far away from the first semiconductor layer, of the second semiconductor layer, wherein the second conductive layer is electrically connected with the second semiconductor layer, the second reflecting layer is electrically connected with the second conductive layer, the metal connecting piece is electrically connected with the second reflecting layer, and the metal connecting piece is electrically connected with the driving backboard; and

the LED display device comprises a first conductive layer and a current expansion structure, wherein the first conductive layer is arranged on one side, far away from the second semiconductor layer, of the first semiconductor layer, the current expansion structure is arranged on one side, far away from the first semiconductor layer, of the first conductive layer, the current expansion structure is located between adjacent Micro LED units, and the position of the pixel isolation structure corresponds to the current expansion structure.

19. The Micro LED display panel of claim 18, wherein the second reflective layer comprises a main reflective layer and a side reflective layer, wherein the main reflective layer is located between the metal connection and the second semiconductor layer, and one end of the side reflective layer is connected to the main reflective layer and the other end extends to a side of the light emitting layer.

20. The Micro LED display panel according to claim 19, wherein a side of the second reflective layer away from the second semiconductor layer has a groove, and an end of the metal connector away from the driving back plate is disposed in the groove.

21. The Micro LED display panel according to any one of claims 10-12, wherein the side of the wavelength converting structure remote from the driving back plate is arranged protruding outwards.

22. The Micro LED display panel of claim 21, wherein the side of the wavelength conversion structure remote from the driving back plate is hemispherical and protrudes outwards.

23. The Micro LED display panel according to any one of claims 10-12, wherein the thickness of the wavelength converting structure is in the range of 1nm to 15nm.

24. The color Micro LED display panel according to any one of claims 10-12, wherein the thickness of the Micro LED unit is in the range of 1 μm to 10 μm.

25. The Micro LED display panel according to any one of claims 10-12, wherein the resolution of the Micro LED array of the Micro LED units in the Micro LED display panel is one of 320 x 240, 640 x 480, 720 x 480, 1280 x 720, 1920 x 1080, 2560 x 1440, 4090 x 2160.

26. A display device comprising a Micro LED display panel according to any one of claims 10-24.