Multicolor LED pixel unit and miniature LED display panel

Abstract

A method for manufacturing a micro light emitting diode (LED) display panel, the method including: forming a stacked structure on a wafer substrate, the stacked structure including a first metal layer, a first type of light emitting layer, a second metal layer, and a second type of light emitting layer in order from bottom to top; forming a plurality of grooves in the stacked structure, wherein the plurality of grooves define a plurality of micro LED display panel areas; patterning the light emitting layer of the second type and the second metal layer; selectively etching the stack structure to expose the side surface of the first metal layer, thereby forming a plurality of first LEDs and a plurality of second LEDs in each micro LED display panel area; and cutting the wafer substrate to form a plurality of micro LED display panels.

Description

[0001] This application is based on and claims priority to U.S. patent application No. 17 / 886,850 filed on August 12, 2022, which is a continuation-in-part of U.S. application No. 17 / 840,516 filed on June 14, 2022, which is a continuation-in-part of application No. 16 / 567, 123 filed on September 11, 2019, now with issued patent No. 11,362,133, and the entire contents of all of the said applications are incorporated herein by reference. Technical Field

[0002] The present disclosure relates generally to the field of micro light emitting diode technology, and more particularly to multi-color LED pixel units and micro LED display panels. Background Art

[0003] A light emitting diode (LED) is a semiconductor diode that can convert electrical energy into light energy. A conventional light emitting diode includes a PN junction with unidirectional conduction. Under forward bias, holes flow from the P region into the N region, and electrons flow from the N region into the P region, and the combination of electrons in the N region and holes in the P region produces spontaneous radiation of excitation light. Electrons and holes have different energy states in different semiconductor materials, so the energy generated by the combination between electrons and holes is different. The higher the energy, the shorter the wavelength of the excitation light. Therefore, LEDs can emit different lights of different wavelengths from ultraviolet light to infrared light, thereby producing multi-color LEDs.

[0004] Multicolor LEDs that emit white light or other colors of light have a wide range of applications, most of which are used in the display field. Conventional LED display panels are formed by assembling single-color LEDs one by one on a substrate. The method for assembling single-color LEDs includes: bonding the LED to an interconnect layer through a metal wire or a connecting electrode of the LED using a metal bonding process or other processes. The process of assembling LEDs of other colors is not performed until the process of assembling the single-color LED is completed, resulting in a complicated process, increased processing difficulty, and increased production costs. In addition, a multicolor display panel manufactured by assembling or forming single LEDs one by one has higher power consumption and reduced brightness and color. Summary of the invention

[0005] According to one aspect of the present disclosure, a method for manufacturing a micro light emitting diode (LED) display panel includes: forming a stacking structure on a wafer substrate, the stacking structure including, in order from bottom to top, a first metal layer, a first type of light emitting layer, a second metal layer, and a second type of light emitting layer; forming a plurality of grooves in the stacking structure, the plurality of grooves defining a plurality of micro LED display panel regions; patterning the second type of light emitting layer and the second metal layer until a portion of a top surface of the first type of light emitting layer is exposed; after patterning the second type of light emitting layer and the second metal layer, selectively etching the stacking structure to expose a side surface of the first metal layer, thereby forming a plurality of first LEDs and a plurality of second LEDs in each micro LED display panel region, each first LED including the first metal layer and the first type of light emitting layer, and each second LED including the first metal layer, the first type of light emitting layer, the second metal layer, and the second type of light emitting layer; and cutting the wafer substrate to form a plurality of micro LED display panels. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is a cross-sectional view showing a multi-color light-emitting pixel unit according to an embodiment of the present disclosure.

[0007] Figure 2 is a cross-sectional view showing a multi-color light-emitting pixel unit according to an embodiment of the present disclosure.

[0008] Figure 3 is a cross-sectional view showing a multi-color light-emitting pixel unit according to an embodiment of the present disclosure.

[0009] Figure 4 is a top view of a multi-color light-emitting pixel unit according to an embodiment of the present disclosure.

[0010] Figure 5 is a cross-sectional view showing a multi-color light-emitting pixel unit according to an embodiment of the present disclosure.

[0011] Figure 6 is to demonstrate the manufacture of an embodiment according to the present disclosure Figure 1 Flow chart of the method for a multi-color light-emitting pixel unit shown in FIG.

[0012] Figures 7 to 10 is a display according to the embodiment of the present disclosure Figure 6 A cross-sectional view of a structure formed during the steps of the method.

[0013] Fig.11 is a display according to the embodiment of the present disclosure Figure 6 Flowchart of details of step S601 in FIG.

[0014] Figures 12 to 21 is a display according to the embodiment of the present disclosure Fig.11 A cross-sectional view of a structure formed in the steps of FIG.

[0015] Fig. 22 is a display according to the embodiment of the present disclosure Figure 6 Flowchart of details of step S604 in FIG.

[0016] Figure 23 to Figure 25 is a display according to the embodiment of the present disclosure Fig. 22 A cross-sectional view of a structure formed in the steps of FIG.

[0017] Fig.26 and Fig. 27 is a cross-sectional view showing a structure formed in a process of manufacturing a first electrical connector according to an embodiment of the present disclosure.

[0018] Fig.28 is a cross-sectional view showing a multi-color light-emitting pixel unit having a micro-gap structure according to an embodiment of the present disclosure.

[0019] Fig.29 is to demonstrate the manufacture of an embodiment according to the present disclosure Figure 3 Flow chart of the method for a multi-color light-emitting pixel unit shown in FIG.

[0020] Figure 30 to Figure 34 is a display according to the embodiment of the present disclosure Fig.29 A cross-sectional view of a structure formed during the steps of the method.

[0021] Fig.35 is a display according to the embodiment of the present disclosure Fig.29 Flowchart of details of step S701 in FIG.

[0022] Fig.36 is a cross-sectional view of a micro-gap structure formed in three types of light emitting layers according to an embodiment of the present disclosure.

[0023] Fig.37 is a display according to the embodiment of the present disclosure Fig.29 Flowchart of details of step S705 in FIG.

[0024] Figures 38 to 40 is a display according to the embodiment of the present disclosure Fig.37 A cross-sectional view of a structure formed in the steps of FIG.

[0025] Fig.41is a flow chart showing a method of manufacturing a micro LED display panel according to an embodiment of the present disclosure.

[0026] Fig.42 It is displayed in Fig.41 A cross-sectional view of a structure formed during the steps of the method.

[0027] Fig.43 It is displayed in Fig.41 A cross-sectional view of a structure formed during the steps of the method.

[0028] Fig.44 It is displayed in Fig.41 A top view of a structure formed in the steps of the method.

[0029] Fig.45 It is displayed in Fig.41 A cross-sectional view of a structure formed during the steps of the method.

[0030] Fig.46 It is displayed in Fig.41 A cross-sectional view of a structure formed during the steps of the method.

[0031] Fig.47 It is displayed in Fig.41 A cross-sectional view of a structure formed during the steps of the method.

[0032] Fig.48 It is displayed in Fig.41 A top view of a structure formed in the steps of the method. DETAILED DESCRIPTION

[0033] Reference will now be made in detail to the present preferred embodiments to provide a further understanding of the invention.The specific embodiments discussed and the drawings are merely illustrative of specific ways to make and use the invention and do not limit the scope of the invention or the appended claims.

[0034] In the following, combined Figures 1 to 44 , the present disclosure is further described by the embodiments of the present disclosure. It should be noted that all the drawings are in a very simplified form and the imprecise scale is only used to help conveniently and clearly explain the embodiments of the present disclosure.

[0035] The multicolor luminous pixel unit disclosed in this article includes at least one type of light-emitting transistor, or several types of light-emitting transistors. Various types of light-emitting transistors include an upper conductive layer, a bottom conductive layer, and a light-emitting layer between the upper conductive layer and the bottom conductive layer. All light-emitting transistors share the same upper conductive layer and the same bottom conductive layer. It should be noted that the light-emitting layer can be a single layer or a multilayer. The intermediate layer can be arranged between two light-emitting layers of the multiple light-emitting layers in the same light-emitting diode. Assume that the multicolor luminous pixel unit includes first to M-th types of light-emitting transistors, where M is an integer and not less than two. Each of the first to M-th types of light-emitting transistors includes at least the same type of light-emitting layer. For example, each of the first to M-th types of light-emitting transistors includes a first type of light-emitting layer. Any of the second to M-th types of light-emitting layers is different from the first type of light-emitting layer. The present disclosure also provides a micro display panel including a plurality of the above-mentioned pixel units arranged in a matrix.

[0036] In some embodiments, the light emitting transistor may be at least one of a light emitting diode (LED), a Schottky light emitting transistor, and the like. The top conductive layer of the light emitting transistor is, but is not limited to, a transparent conductive layer, and the bottom conductive layer of the light emitting transistor is, but is not limited to, a metal layer. In the following, LED is used as an example of a light emitting transistor, but this does not limit the scope of the present disclosure. Those skilled in the art can change the LED into another light emitting transistor according to conventional technical means.

[0037] Figure 1 is a cross-sectional view showing a multi-color light-emitting pixel unit 1000 according to an embodiment of the present disclosure. Figure 1 The multi-color light-emitting pixel unit 1000 includes at least a first type LED 01 and a second type LED 02 arranged side by side on the substrate 100. The top of the first type LED 01 is not on the same horizontal plane as the top of the second type LED 02. The type of the first type LED 01 is different from the type of the second type LED 02. Figure 1As shown, the top of the first type LED 01 is lower than the top of the second type LED 02. According to the embodiment, the first type LED 01 is selected from one of a red LED, a green LED, a blue LED, a yellow LED, an orange LED or a cyan LED, and the second type LED 02 is selected from one of a green LED, a blue LED, a red LED, a yellow LED, an orange LED or a cyan LED. In addition, the size of the light emitting area of ​​the first type LED 01 is different from the size of the light emitting area of ​​the second type LED 02. For example, the first type LED 01 is a red LED, the second type LED 02 is a green LED, and the size of the light emitting area of ​​the red LED is different from the size of the light emitting area of ​​the green LED. In addition, according to different colors that may be required, the light emitting area of ​​the green LED may be smaller than the light emitting area of ​​the red LED.

[0038] Furthermore, the isolation structure 07 is arranged between the LEDs of the first type and the LEDs of the second type. Figure 1 In the embodiment shown in FIG. 1 , the isolation structure 07 between the first type LED 01 and the second type LED 02 is an isolation trench. The multi-color light-emitting pixel unit 1000 includes a first metal layer, a first type light-emitting layer, a second metal layer, and a second type light-emitting layer. Figure 1As shown in FIG. 1 , the first type LED 01 includes at least a first segment 101-1 of a first metal layer and a first segment 102-1 of a first type of light emitting layer in order from bottom to top. The first segment 101-1 of the first metal layer constitutes a bottom conductive layer of the first type LED 01. The second type LED 02 includes at least a second segment 101-2 of a first metal layer, a second segment 102-2 of a first type of light emitting layer, a first segment 201-1 of a second metal layer and a first segment 202-2 of a second type of light emitting layer, and a first electrical connector 203 in order from bottom to top. The first segment 101-1 of the first metal layer and the second segment 101-2 of the first metal layer are electrically connected to the substrate 100. The isolation structure 07 isolates the first segment 101-1 of the first metal layer in the first type LED 01 from the second segment 101-2 of the first metal layer in the second type LED 02. The isolation structure 07 also isolates the first segment 102-1 of the first type of light emitting layer in the first type of LED 01 from the second segment 102-2 of the first type of light emitting layer in the second type of LED 02. In addition, in order to simplify the manufacturing process, the first segment 201-1 of the second metal layer in the second type of LED 02, the second segment 102-2 of the first type of light emitting layer, and the second segment 101-2 of the first metal layer are electrically connected to each other through the first electrical connector 203. According to one embodiment, the first electrical connector 203 can be attached to and contact a portion or all of the side wall surface of the second type of LED 02. Alternatively, the first electrical connector 203 can only be attached to and contact the surface of the first segment 201-1 of the second metal layer and the second segment 101-2 of the first metal layer in the second type of LED 02. Alternatively, the first electrical connector 203 may be formed as a conductive side arm that is attached to and contacts the sidewalls of the first segment 201-1 of the second metal layer, the second segment 102-2 of the first type of light emitting layer, and the second segment 101-2 of the first metal layer. The electrical connector 203 between the second segment 101-2 of the first metal layer and the first segment 201-1 of the second metal layer in the second type of LED 02 may have other shapes, such as a curve. Figure 1 In the implementation shown in , the first electrical connector 203 is attached to the side wall of the second type of LED 02 so that the first electrical connector 203 follows the surface topography of the side wall of the second type of LED 02 .

[0039] refer to Figure 1, a top insulating layer 04 and a top transparent conductive layer 05 are arranged on the first segment 102-1 of the first type of light emitting layer in the first type of LED 01 and the first segment 202-1 of the second type of light emitting layer in the second type of LED 02. The top insulating layer 04 covers the first segment 102-1 of the first type of light emitting layer, the first segment 202-1 of the second type of light emitting layer, and the exposed substrate 100. The top insulating layer 04 has an opening, which exposes a portion of the top surface of the first segment 102-1 of the first type of light emitting layer and the first segment 202-1 of the second type of light emitting layer. The top transparent conductive layer 05 covers the top insulating layer 04 and is formed in the opening of the top insulating layer 04, and thereby contacts the exposed top surface of the first segment 102-1 of the first type of light emitting layer and the first segment 202-1 of the second type of light emitting layer via the opening.

[0040] The substrate 100 is an integrated circuit (IC) substrate. The IC substrate includes an interconnection layer that is electrically connected to a first segment 101-1 of a first metal layer in a first type LED 01 and a second segment 101-2 of a first metal layer in a second type LED 02. Since the first electrical connector 203 is connected to the second segment 101-2 of the first metal layer in the second type LED 02, the first electrical connector 203 is connected to the interconnection layer in the substrate 100. In addition, referring to Figure 1 The bottom of the first electrical connector 203 extends to the substrate 100 to connect with the interconnection layer. Here, the IC substrate at least includes a driving circuit. The driving circuit controls each LED separately.

[0041] Figure 2 is a cross-sectional view showing a multi-color light-emitting pixel unit 2000 according to an embodiment of the present disclosure. Figure 2 , the multi-color light-emitting pixel unit 2000 includes at least a first type of LED 01, a second type of LED 02, and a third type of LED 03 arranged on the same substrate 100. The third type of LED 03 is different from the first type of LED 01 and the second type of LED 02. Here, the first type of LED 01 is selected from one of a red LED, a green LED, a blue LED, a yellow LED, an orange LED, or a cyan LED; the second type of LED 02 is selected from one of a green LED, a blue LED, a red LED, a yellow LED, an orange LED, or a cyan LED; and the third type of LED 03 is selected from one of a blue LED, a red LED, a green LED, a yellow LED, an orange LED, or a cyan LED. For example, a red LED is selected as the first type of LED 01, a green LED is selected as the second type of LED 02, and a blue LED is selected as the third type of LED 03. Reference Figure 2, the height of the third type of LED 03 is different from the height of the first type of LED 01. In addition, the height of the first type of LED 01 is different from the height of the second type of LED 02, and the height of the second type of LED 02 is the same as the height of the third type of LED 03. In other embodiments, the height of the third type of LED 03, the height of the first type of LED 01, and the height of the second type of LED 02 may be different from each other, such as Figure 3 shown.

[0042] In the multi-color light-emitting pixel unit 2000, the structures of the first type LED 01 and the second type LED 02 are the same as those of the first type LED 01 and the second type LED 02 in the multi-color light-emitting pixel unit 2000, and thus their detailed descriptions are not repeated. The third type LED 03 in the multi-color light-emitting pixel unit 2000 includes, in order from bottom to top, at least a third segment 101-3 of the first metal layer, a third segment 102-3 of the first type light-emitting layer, a first segment 301-1 of the third metal layer, and a first segment 302-1 of the third type light-emitting layer, and a second electrical connector 303 connecting the third segment 101-3 of the first metal layer and the first segment 301-1 of the third metal layer. The multi-color light-emitting pixel unit 2000 further includes a top isolation layer 04, which covers the first type LED 01, the second type LED 02, and the third type LED 03 and has an opening, wherein the opening exposes a portion of the first segment of the first type light-emitting layer 102-1, a portion of the first segment 202-1 of the second type light-emitting layer, and a portion of the first segment 302-1 of the third type light-emitting layer in the first type LED 01. The top electrode layer 05 is formed on the top of the top isolation layer 04, and contacts the first segment 102-1 of the first type light-emitting layer, the first segment 202-1 of the second type light-emitting layer, and the first segment 302-1 of the third type light-emitting layer via the opening of the top isolation layer 04.

[0043] Figure 3 is a cross-sectional view showing a multi-color light-emitting pixel unit 3000 according to an embodiment of the present disclosure. Figure 3 In the multi-color light-emitting pixel unit 3000 , the top of the third type LED 03 is higher than the top of the second type LED 02 , and the height of the first type LED is different from the height of the second type LED 03 .

[0044] Figure 4 4 is a top view of a multi-color light-emitting pixel unit 4000 according to an embodiment of the present disclosure. The multi-color light-emitting pixel unit 4000 may be Figure 2 The multi-color light-emitting pixel unit 2000 or Figure 3 The multi-color light-emitting pixel unit 3000 shown in FIG. Figure 4 The arrangement of three types of LEDs 01, 02, and 03 in the pixel unit is shown, but the present disclosure also includes other arrangements, such as a matrix. Here, the size of the light-emitting area of ​​the third type of LED 03 is different from the size of the light-emitting area of ​​the first type of LED 01, and is different from the size of the light-emitting area of ​​the second type of LED 02. For example, the first type of LED 01 is a red LED, the second type of LED 02 is a green LED, and the third type of LED 03 is a blue LED. The size of the light-emitting area of ​​each of the first type of LED 01, the second type of LED 02, and the third type of LED 03 can be determined according to the color of light that the multi-color light-emitting pixel unit 4000 needs to emit. When white light is required, the size of the light-emitting area of ​​the red LED is larger than the size of the light-emitting area of ​​the green LED, and the size of the light-emitting area of ​​the blue LED is larger than the size of the light-emitting area of ​​the green LED. Figure 4 As shown, the space between the red LED and the blue LED is larger than the space between the blue LED and the green LED; the space between the red LED and the green LED is larger than the space between the blue LED and the green LED, thereby achieving a better lighting effect.

[0045] Return to reference Figure 3 , the isolation structure 07 is arranged between two of the first type LED 01, the second type LED 02 and the third type LED 03. The isolation structure is an isolation trench. The first type LED 01, the second type LED 02 and the third type LED 03 are formed by the first metal layer 101, the first type light emitting layer 102, the second metal layer 201, the second type light emitting layer 202, the third metal layer 301 and the third type light emitting layer 302. Figure 3 The first type of LED 01 and the second type of LED 02 are Figure 2 The first type of LED 01 and the second type of LED 02 are the same. Specifically, Figure 3As shown in , the first type of LED 01 includes at least a first segment 101-1 of a first metal layer and a first segment 102-1 of a first type of light emitting layer in order from bottom to top. The second type of LED 02 includes at least a second segment 101-2 of a first metal layer, a second segment 102-2 of a first type of light emitting layer, a first segment 201-1 of a second metal layer and a first segment 202-1 of a second type of light emitting layer, and a first electrical connector 203 in order from bottom to top. The third type of LED 03 includes at least a third segment 101-3 of a first metal layer, a third segment 102-3 of a first type of light emitting layer, a second segment 201-2 of a second metal layer, a second segment 202-2 of a second type of light emitting layer, a first segment 301-1 of a third metal layer and a first segment 302-1 of a third type of light emitting layer, and a second electrical connector 303 in order from bottom to top. Figure 3As shown, the first segment 101-1 of the first metal layer, the second segment 101-2 of the first metal layer, and the third segment 101-3 of the first metal layer are electrically connected to the substrate 100. The first electrical connector 203 in the second type LED 02 electrically connects the first segment 201-1 of the second metal layer with the second segment 101-2 of the first metal layer. The second electrical connector 303 in the third type LED 03 electrically connects the first segment 301-1 of the third metal layer with the second segment 201-2 of the second metal layer and the third segment 101-3 of the first metal layer. The isolation structure 07 isolates the first segment 101-1 of the first metal layer in the first type LED 01 from the second segment 101-2 of the first metal layer in the second type LED 02 and the third segment 101-3 of the first metal layer in the third type LED 03, isolates the first segment 102-1 of the first type of light-emitting layer in the first type LED 01 from the second segment 102-2 of the first type of light-emitting layer in the second type LED 02 and the third segment 102-3 of the first type of light-emitting layer in the third type LED 03, isolates the first segment 201-1 of the second metal layer in the second type LED 02 from the second segment 201-2 of the second metal layer in the third type LED 03, and isolates the first segment 202-1 of the second type of light-emitting layer in the second type LED 02 from the second segment 202-2 of the second type of light-emitting layer in the third type LED 03. It should be noted that the first electrical connector 203 is used to connect the second segment 102-2 of the first type of light emitting layer in the second type of LED 02 with the second segment 101-2 of the first metal layer, and the second electrical connector 303 is used to connect the second segment 202-2 of the second type of light emitting layer and the third segment 102-3 of the first type of light emitting layer in the third type of LED 03 with the third segment 101-3 of the first metal layer. Figure 1In the same manner, the first electrical connector 203 also connects the second segment 102-2 of the first type of light emitting layer to the second segment 101-2 of the first metal layer. That is, in the second type of LED 02, the first electrical connector 203 connects the first segment 201-1 of the second metal layer and the second segment 102-2 of the first type of light emitting layer to the second segment 101-2 of the first metal layer. The second electrical connector 303 also connects the second segment 202-2 of the second type of light emitting layer to the third segment 101-3 of the first metal layer. That is, in the third type of LED 03, the second electrical connector 303 connects the first segment 301-1 of the third metal layer, the second segment 202-2 of the second type of light emitting layer, and the second segment 201-2 of the second metal layer to the third segment 101-3 of the first metal layer. Alternatively, the second electrical connector 303 also connects the second segment 202-2 of the second type of light emitting layer and the third segment 102-3 of the first type of light emitting layer to the third segment 101-3 of the first metal layer. That is, in the third type of LED 03, the second electrical connector 303 connects the first segment 301-1 of the third metal layer, the second segment 202-2 of the second type of light-emitting layer, the second segment 201-2 of the second metal layer, and the third segment 102-3 of the first type of light-emitting layer with the third segment 101-3 of the first metal layer. In addition, the bottom of the first electrical connector 203 and the bottom of the second electrical connector 303 are respectively and directly in contact with the substrate 100, thereby simplifying the manufacturing process. It should be noted that the materials of the first electrical connector 203 and the second electrical connector 303 are formed of conductive metal. In the embodiment, the second electrical connector 303 is attached to and contacts the side wall surface of the third type of LED 03.

[0046] In one embodiment, the first type of light emitting layer is a red light emitting layer, the second type of light emitting layer is a green light emitting layer, and the third type of light emitting layer is a blue light emitting layer, the first type of LED 01 is a red LED 01, the second type of LED 02 is a green LED 02, and the third type of LED 03 is a blue LED 03. In the red LED 01, the voltage applied between the top transparent conductive layer 05 and the first segment 101-1 of the first metal layer is applied to the first segment 102-1 of the red light emitting layer. Therefore, the first segment 102-1 of the red light emitting layer in the red LED 01 emits red light. In the green LED 02, the first electrical connector 203 electrically connects the second segment 102-2 of the red light emitting layer with the second segment 101-2 of the first metal layer, so that the voltage applied between the top transparent conductive layer 05 and the second segment 101-2 of the first metal layer is applied only to the first segment 202-1 of the green light emitting layer. Therefore, only the first segment 202-1 of the green light emitting layer in the green LED 02 emits green light, while the second segment 102-2 of the red light emitting layer in the green LED 02 does not emit light. In the third type of LED 03, the second electrical connector 303 electrically connects the third segment 102-3 of the red light emitting layer and the second segment 202-2 of the green light emitting layer with the third segment 101-3 of the first metal layer, so that the voltage applied between the top transparent conductive layer 05 and the third segment 101-3 of the first metal layer is applied only to the first segment 302-1 of the blue light emitting layer. Therefore, only the first segment 302-1 of the blue light emitting layer in the blue LED 03 emits blue light, while the third segment 102-3 of the red light emitting layer and the second segment 202-2 of the green light emitting layer in the blue LED 03 do not emit light.

[0047] Reference again Figure 3 , a top insulating layer 04 and a top transparent conductive layer 05 are arranged on the first type LED 01, the second type LED 02, and the third type LED 03. The top insulating layer 04 covers the first segment 102-1 of the first type light emitting layer, the first segment 202-1 of the second type light emitting layer, the first segment 302-1 of the third type light emitting layer, and the exposed substrate 100. An opening is arranged in the top insulating layer 04 to expose a portion of the top surface of the first segment 102-1 of the first type light emitting layer, the first segment 202-1 of the second type light emitting layer, and the first segment 302-1 of the third type light emitting layer. The top transparent conductive layer 05 covers the top insulating layer 04 and is formed in the opening of the top insulating layer 04, thereby contacting the exposed top surface of the first segment 102-1 of the first type light emitting layer, the exposed top surface of the first segment 202-1 of the second type light emitting layer, and the exposed top surface of the first segment 302-1 of the third type light emitting layer.

[0048] The detailed description of the substrate 100 in the multi-color light-emitting pixel unit 3000 having at least three types of LEDs corresponds to Figure 1 It should be noted that the interconnection layer in the IC substrate 100 is electrically connected to the first type LED 01, the second type LED 02, and the third type LED 03. The driving circuit in the IC substrate 100 controls each LED separately.

[0049] exist Figures 1 to 4 In the multi-color light-emitting pixel units 1000 to 4000, one or more of the light-emitting layers 102, 202 and 302 may have a micro-gap structure. Figure 1 In the multi-color light-emitting pixel unit 1000 shown, the first type of light-emitting layer 102 may have a micro-gap structure, or the second type of light-emitting layer 202 may have a micro-gap structure, or both the first type of light-emitting layer 102 and the second type of light-emitting layer 202 may have a micro-gap structure. As another example, in Figure 3 In the multi-color light-emitting pixel unit 3000 shown, the first type of light-emitting layer 102 may have a micro-gap structure, or the second type of light-emitting layer 202 may have a micro-gap structure, or the third type of light-emitting layer 302 may have a micro-gap structure, or the first type of light-emitting layer 102 and the second type of light-emitting layer 202 may both have a micro-gap structure, or the second type of light-emitting layer 202 and the third type of light-emitting layer 302 may both have a micro-gap structure, or the first type of light-emitting layer 102 and the third type of light-emitting layer 302 may both have a micro-gap structure, or the first type of light-emitting layer 102, the second type of light-emitting layer 202 and the third type of light-emitting layer 302 may all have a micro-gap structure. Here, Figures 1 to 3 Each of the micro-gap structures in the multi-color light-emitting pixel units 1000 to 3000 shown in the figure may be, but is not limited to, an air gap. The air gap is sealed. Preferably, the cross-sectional size of the air gap is not greater than 2 nm, so as to release the stress in the light-emitting layer and avoid bending of the light-emitting layer without affecting the light-emitting efficiency of the light-emitting layer. Here, the cross-sectional size of the air gap may be the diameter of the cross section of the air gap, or the length or width of the cross section of the air gap.

[0050] Figure 5 is a cross-sectional view showing a multi-color light-emitting pixel unit 5000 according to an embodiment of the present disclosure. Figure 5As shown, each of the first type of light-emitting layer 102, the second type of light-emitting layer 202, and the third type of light-emitting layer 302 may have a plurality of micro-gap structures 06. Each of the micro-gap structures 06 extends in a direction perpendicular to the substrate 100 and passes through a corresponding light-emitting layer, such as the first type of light-emitting layer 102, the second type of light-emitting layer 202, or the third type of light-emitting layer 302. When a plurality of light-emitting layers are used in the embodiment, the micro-gap structure 06 is arranged in at least one light-emitting layer, preferably in the top light-emitting layer.

[0051] Still refer to Figure 5 , the micro-gap structures 06 are staggered in the plurality of light-emitting layers. That is, the micro-gap structures 06 in the first type of light-emitting layer 102 are not vertically aligned with the micro-gap structures 06 in the second type of light-emitting layer 202, and the micro-gap structures 06 in the second type of light-emitting layer 202 are not vertically aligned with the micro-gap structures 06 in the third type of light-emitting layer 302. In each of the second type of LED 02 and the third type of LED 03, the micro-gap structures in the first type of light-emitting layer 102 are isolated and sealed between the second metal layer 201 at the top of the first type of light-emitting layer 102 and the first metal layer 101 at the bottom thereof. In the third type of LED 03, the micro-gap structures 06 in the second type of light-emitting layer 202 are isolated and sealed between the third metal layer 301 at the top of the second light-emitting layer 202 and the second metal layer 201 at the bottom thereof, and the micro-gap structures 06 in the third type of light-emitting layer 302 are isolated and sealed between the top isolation layer 04 at the top of the third type of light-emitting layer 302 and the third metal layer 301 at the bottom thereof.

[0052] In a similar manner, in a multicolor light-emitting pixel unit including first to M-th type LEDs in another embodiment of the present disclosure, the M-th type LED has M light-emitting layers, and a metal layer is arranged at the bottom of each light-emitting layer, where M is a positive integer and is greater than or equal to the number two. In each of the first to M-th type LEDs, a top conductive layer (as an upper conductive layer) is arranged on top of the top light-emitting layer, so that a microgap structure in the top light-emitting layer can be isolated and sealed between the top conductive layer and the metal layer at the bottom of the top light-emitting layer. The microgap structure in each light-emitting layer is isolated and sealed between the metal layers at the top and bottom of the relative light-emitting layer, respectively.

[0053] In addition, similar to Figures 1 to 4The multi-color light-emitting pixel units 1000 to 4000 in the multi-color light-emitting pixel unit according to another embodiment of the present disclosure include a plurality of LEDs (including LEDs of the first type to the Mth type). The Mth type of LED includes at least all the light-emitting layers and metal layers constructed in the (M-1)th type of LED and the Mth light-emitting layer and the Mth metal layer. On this basis, the Mth type of LED has an (M-1)th electrical connector, which is connected to the Mth metal layer, the (M-1)th metal layer, ..., and the first metal layer. In addition, the (M-1)th electrical connector can be connected to the Mth metal layer, the (M-1)th type of light-emitting layer, the (M-1)th metal layer, ..., the first type of light-emitting layer and the first metal layer. The arrangement of the (M-1)th electrical connector can refer to Figure 1 Description of the first electrical connector 203 in . The first to (M-1)th electrical connectors connect the first to M-th metal layers, and the first to (M-1)th electrical connectors can directly contact the substrate and the first metal layer. Here, there are differences from the first type of LED to the M-th type of LED. In addition, each LED can be selected from a red LED, a green LED, a blue LED, a yellow LED, an orange LED, a purple LED or a cyan LED. Here, the LEDs of different colors are conventional LEDs, which are known to those skilled in the art and will not be described here. In addition, the first type of LED to the M-th type of LED are spaced apart on the same substrate. The top isolation layer covers the exposed surface of the substrate and the exposed surfaces of the first to M-th types of LEDs. The top isolation layer of each type of LED has its opening, and the transparent conductive layer covers the surface of the top isolation layer and is filled in the opening, wherein the transparent conductive layer at the bottom of the opening is electrically in contact with the top light-emitting layer of each type of LED. Reference Figure 4 and Figure 5 In a pixel unit having M types of LEDs, the sizes of the light emitting areas of the first to M-th types of LEDs are different from each other. According to the arrangement of the LEDs in the pixel unit, the size of the light emitting area of ​​the first type of LED is larger than the size of the light emitting area of ​​the other types of LEDs. Optionally, the first type of LED is a red LED, and its light emitting area is larger than the light emitting area of ​​the other types of LEDs. Alternatively, the other types of LEDs include at least a green LED or a blue LED.

[0054] A multi-color micro display panel according to an embodiment of the present disclosure is also provided. The micro display panel comprises a plurality of multi-color pixel units arranged in a matrix. The multi-color pixel units herein may be the above-mentioned LED pixel units.

[0055] The method for manufacturing a multi-color light-emitting pixel unit will be further described below in conjunction with the accompanying drawings.

[0056] Figure 6 The invention is to demonstrate the manufacture of an embodiment according to the present disclosure Figure 1 A flow chart of a method for a multi-color light-emitting pixel unit is shown. Figures 7 to 10 is a display according to the embodiment of the present disclosure Figure 6 A cross-sectional view of the structure formed in the steps shown in FIG. Figure 6 , manufacturing as Figure 1 The method of the multi-color light-emitting pixel unit shown includes the following steps.

[0057] In step S601, refer to Figure 7 , a stacked structure including a first metal layer 101, a first type of light emitting layer 102, a second metal layer 201, and a second type of light emitting layer 202 is formed from bottom to top on a substrate 100. In other words, the first type of light emitting layer 102 and the second type of light emitting layer 202 are stacked from bottom to top on the substrate 100. The first metal layer 101 is formed at the bottom of the first type of light emitting layer 102. The second metal layer 201 is formed at the bottom of the second type of light emitting layer 202. The second metal layer 201 is arranged between the first type of light emitting layer 102 and the second type of light emitting layer 202.

[0058] More specifically, the substrate 100 may be, but is not limited to, an IC substrate.

[0059] Fig.11 is a display according to the embodiment of the present disclosure Figure 6 Flowchart of details of step S601 in FIG. Figures 12 to 21 is a display according to the embodiment of the present disclosure Fig.11 A cross-sectional view of the structure formed in the steps shown in FIG. Fig.11 , step S601 further includes the following specific steps.

[0060] In step S101, refer to Fig.12 , a first metal bonding layer M01 is formed on the substrate 100 , a first type of light emitting layer 102 is formed on the first base B1 , and a second metal bonding layer M02 is formed on the top of the first type of light emitting layer 102 .

[0061] More specifically, the first metal bonding layer M01 can be prepared by, but not limited to, physical vapor deposition (such as evaporation, sputtering, etc.). The material of the first substrate B1 is designed according to the first type of light-emitting layer 102. For example, the first substrate B1 can be a gallium nitride (GaN) substrate. The first type of light-emitting layer 102 can be formed by, but not limited to, epitaxial growth on the first substrate B1. The second metal bonding layer M02 can be prepared by, but not limited to, physical vapor deposition (such as evaporation).

[0062] In step S102, combining Fig.12 ,refer to Fig.13 , the first substrate B1 is turned upside down so that the second metal bonding layer M02 faces the first metal bonding layer M01, and then the second metal bonding layer M02 is bonded to the first metal bonding layer M01 to form a first metal layer 101.

[0063] In step S103, Fig.13 ,refer to Fig.14 , remove the first substrate B1.

[0064] Here, after removing the first substrate B1, refer to Fig.15 , step S103 may further include: thinning the first type light emitting layer 102 .

[0065] In addition, according to the embodiment, after removing the first substrate B1 or thinning the first type light emitting layer 102, and before forming the third metal bonding layer, refer to Fig.16 , step S103 may further include: forming a microgap structure 06 in the first type of light emitting layer 102. The microgap structure 06 is formed by, but not limited to, photolithography and etching. In the photolithography, a photolithography pattern is designed according to the size of the microgap structure 06. According to the embodiment, the cross-sectional size of the microgap structure pattern is not greater than 2 nm. Here, the cross-sectional size of the air gap may be the diameter of the cross section of the air gap, or the length or width of the cross section of the air gap.

[0066] In step S104, refer to Fig.17 , a third metal bonding layer M03 is formed on the first type light emitting layer 102 , a second type light emitting layer 202 is formed on the second substrate B2 , and a fourth metal bonding layer M04 is formed on top of the second type light emitting layer 202 .

[0067] In step S105, Fig.17 ,refer to Fig.18 , the second substrate B2 is turned upside down so that the fourth metal bonding layer M04 faces the third metal bonding layer M03, and the fourth metal bonding layer M04 is bonded to the third metal bonding layer M03 to form a second metal layer 201.

[0068] In step S106, Fig.18 ,refer to Fig.19 , remove the second substrate B2.

[0069] Here, after removing the second substrate B2, refer to Fig. 20 In step S106, the second type light emitting layer 202 is thinned.

[0070] According to the embodiment, after removing the second substrate B2 or thinning the second type light emitting layer 202, refer to Fig.21 In step S106, a micro-gap structure 06 is formed in the second type light emitting layer 202. The micro-gap structure 06 is formed using a process similar to that of forming the micro-gap structure 06 in the first type light emitting layer 102. Therefore, the process of forming the micro-gap structure 06 in the second type light emitting layer 202 will not be repeatedly described.

[0071] Return to reference Figures 6 to 10 , the process after step S601 according to the implementation scheme of the present disclosure will be further described below.

[0072] In step S602, refer to Figure 8 , the second type light emitting layer 202 and the second metal layer 201 are patterned until a portion of the top of the first type light emitting layer 102 is exposed, thereby forming a stepped structure made of the second type light emitting layer 202 on the first type light emitting layer 102 .

[0073] More specifically, the process of patterning the second type of light emitting layer 202 and the second metal layer 201 can be performed by photolithography and plasma etching. The process of patterning the second type of light emitting layer 202 and the second metal layer 201 also includes: etching the top of the first type of light emitting layer 102. The parameters of the patterning process can be set according to actual needs and will not be limited here.

[0074] In step S603, refer to Fig. 9 According to the preset first type light emitting area A01 and the preset second type light emitting area A02, the second metal layer 201, the first type light emitting layer 102 and the first metal layer 101 are etched, so as to divide the first type light emitting layer 102 in the first type light emitting area A01 from the first type light emitting layer 102 in the second type light emitting area A02, and divide the first metal layer 101 in the first type light emitting area A01 from the first metal layer 101 in the second type light emitting area A02. As a result of step S603, a first type LED 01 including a first segment 101-1 of the first metal layer and a first segment 102-1 of the first type light emitting layer, and a second type LED 02 including a second segment 101-2 of the first metal layer, a second segment 102-2 of the first type light emitting layer, a first segment 201-1 of the second metal layer and a second segment 202-1 of the second type light emitting layer are formed.

[0075] Here, the process of etching the second type light emitting layer 202, the second metal layer 201, the first type light emitting layer 102 and the first metal layer 101 is performed by photolithography and etching. The parameters of the etching process can be set according to actual needs.

[0076] According to the embodiment, as a result of step S603, a plurality of multi-color light-emitting pixel units are divided into each other according to a preset pixel unit array. In this way, the light-emitting transistors in the pixel unit and / or the pixel unit array can be prepared by a division step, which simplifies the process and reduces the production cost, and especially promotes mass production.

[0077] In step S604, refer to Fig.10 A shared top electrode layer 05 serving as an extraction electrode of the second metal layer 201 is formed on top of the first segment 102-1 of the first type light emitting layer and the first segment 202-1 of the second type light emitting layer in the second type light emitting area A02.

[0078] Fig. 22 is a display according to the embodiment of the present disclosure Figure 6 Flowchart of details of step S604 in FIG. Figure 23 to Figure 25 is a display according to the embodiment of the present disclosure Fig. 22 A cross-sectional view of the structure formed in the steps shown in FIG. Fig. 22 The specific process of step S604 includes the following steps.

[0079] In step S401, refer to Fig.23 , a portion of the first segment 202-1 of the second type light emitting layer is removed, thereby exposing a portion of the first segment 201-1 of the second metal layer.

[0080] In step S402, refer to Fig.24 A first electrical connector 203 is formed on the sidewalls and top of the first segment 201-1 of the second metal layer in the second type light-emitting area A02, on the sidewalls of the second segment 102-2 of the first type light-emitting layer, and on the sidewalls of the second segment 101-2 of the first metal layer.

[0081] Figure 26 to Figure 27 is a cross-sectional view showing a structure formed in a step of manufacturing the first electrical connector 203 according to an embodiment of the present disclosure. In step S402, the first electrical connector 203 is formed through the following specific steps.

[0082] In step S4021, Fig.24 ,refer to Fig.26, a mask Y is formed to shield the area without the first electrical connector 203, thereby exposing the top and side walls of the first segment 201-1 of the second metal layer in the second type of light-emitting area A02, the side walls of the second segment 102-2 of the first type of light-emitting layer, and the side walls of the second segment 101-2 of the first metal layer.

[0083] In step S4022, refer to Fig. 27 After completing step S4021 , a conductive material 203 ′ is deposited on the substrate 100 .

[0084] In step S4023, refer again to Fig.10 , remove mask Y and the conductive material 203' on mask Y, thereby forming a first electrical connector 203 on the top and side wall of the first segment 201-1 of the second metal layer of the second type of light-emitting area A02, on the side wall of the second segment 102-2 of the first type of light-emitting layer, and on the side wall of the second segment 101-2 of the first metal layer.

[0085] The process of manufacturing the shared top electrode layer 05 will be further described below.

[0086] In step S403, refer to Fig.25 The isolation layer 04 is formed to cover the first type light emitting area A01, the second type light emitting area A02 and the exposed surface of the substrate 100. The isolation layer 04 has an opening on the first segment 102-1 of the first type light emitting layer of the first type light emitting area A01 and the first segment 202-1 of the second type light emitting layer of the second type light emitting area A02.

[0087] In step S404, refer again to Fig.10 After step S403, a continuous shared top electrode layer 05 is formed on the entire substrate 100 by, for example, deposition. The shared top electrode layer 05 formed in the opening is connected to the first segment 102-1 of the first type of light emitting layer in the first type of light emitting area A01 and the first segment 202-1 of the second type of light emitting layer in the second type of light emitting area A02.

[0088] Fig.28 The structure of a multi-color light-emitting pixel unit according to an embodiment of the present disclosure is shown, and the multi-color light-emitting pixel unit has a micro-gap structure in the first type of light-emitting layer 102 and the second type of light-emitting layer 202 .

[0089] Fig.29 is to demonstrate the manufacture of an embodiment according to the present disclosure Figure 3 A flow chart of a method for producing a multi-color light-emitting pixel unit 3000 is shown. Figure 30 to Figure 34 is a display according to the embodiment of the present disclosure Figure 6A cross-sectional view of the structure formed in the steps shown in FIG. Fig.29 , manufacturing as Figure 3 The method of the multi-color light-emitting pixel unit 3000 shown includes the following steps.

[0090] In step S701, refer to Fig.30 , a stacked structure including a first metal layer 101, a first type of light emitting layer 102, a second metal layer 201, a second type of light emitting layer 202, a third metal layer 301, and a third type of light emitting layer 302 is formed on a substrate 100 in order from bottom to top. In other words, the first type of light emitting layer 102, the second type of light emitting layer 202, and the third type of light emitting layer 302 are stacked on the substrate 100 from bottom to top. The first metal layer 101 is formed at the bottom of the first type of light emitting layer 102. The second metal layer 201 is formed at the bottom of the second type of light emitting layer 202. The third metal layer 301 is formed at the bottom of the third type of light emitting layer 302. The second metal layer 201 is arranged between the first type of light emitting layer 102 and the second type of light emitting layer 202. The third metal layer 301 is arranged between the second type of light emitting layer 202 and the third type of light emitting layer 302.

[0091] Fig.35 is a display according to the embodiment of the present disclosure Fig.29 Detailed flowchart of step S701 in FIG. Fig.30 ,refer to Fig.35 , step S701 further includes the following steps. It should be noted that the structures formed in steps S801 to S809 of this embodiment are not shown in the drawings. However, those skilled in the art can understand steps S801 to S809 of this embodiment with reference to steps S101 to S109 of the above-mentioned embodiment.

[0092] In step S801 , a first metal bonding layer is formed on the substrate 100 , a first type of light emitting layer 102 is formed on the first base, and a second metal bonding layer is formed on top of the first type of light emitting layer 102 .

[0093] More specifically, the first metal bonding layer can be prepared by, but not limited to, physical vapor deposition (such as evaporation, sputtering, etc.). The material of the first substrate is designed according to the first type of light-emitting layer 10. For example, the first substrate can be a gallium nitride (GaN) substrate. The first type of light-emitting layer 102 can be made by, but not limited to, epitaxial growth on the first substrate. The second metal bonding layer can be prepared by, but not limited to, physical vapor deposition (such as evaporation).

[0094] In step S802 , the first substrate is turned upside down so that the second metal bonding layer faces the first metal bonding layer, and the second metal bonding layer is bonded to the first metal bonding layer to form the first metal layer 101 .

[0095] In step S803 , the first substrate is removed.

[0096] Here, after removing the first substrate, step S803 may further include: thinning the first type light emitting layer 102. In addition, after removing the first substrate or thinning the first type light emitting layer 102, and before forming the third metal bonding layer, refer to Fig.36 , step S803 may further include: forming a micro-gap structure 06 in the first type light emitting layer 102. The micro-gap structure 06 is formed by, but not limited to, photolithography and etching. In the photolithography, a photolithography pattern is designed according to the size of the micro-gap structure 06. According to the embodiment, the cross-sectional size of the micro-gap structure pattern is not greater than 2 nm.

[0097] In step S804 , a third metal bonding layer is formed on the first type light emitting layer 102 , a second type light emitting layer 202 is formed on the second substrate, and a fourth metal bonding layer is formed on top of the second type light emitting layer 202 .

[0098] In step S805 , the second substrate is turned upside down so that the fourth metal bonding layer faces the third metal bonding layer, and then the fourth metal bonding layer is bonded to the third metal bonding layer to form the second metal layer 201 .

[0099] In step S806 , the second substrate is removed.

[0100] Here, after removing the second substrate, step S106 may further include: thinning the second type of light emitting layer 202. In addition, after removing the second substrate or thinning the second type of light emitting layer 202, refer to Fig.36 , step S106 further includes: forming a micro-gap structure 06 in the second type light emitting layer 202. The micro-gap structure 06 can be formed using a process similar to the above-described process of forming the micro-gap structure 06. Therefore, the process of forming the micro-gap structure 06 will not be repeatedly described.

[0101] In step S807 , a fifth metal bonding layer is formed on the second type light emitting layer 202 , a third type light emitting layer 302 is formed on the third substrate, and a sixth metal bonding layer is formed on top of the third type light emitting layer 302 .

[0102] In step S808 , the third substrate is turned upside down so that the sixth metal bonding layer faces the fifth metal bonding layer, and then the sixth metal bonding layer is bonded to the fifth metal bonding layer to form a third metal layer 301 .

[0103] In step S809 , the third substrate is removed.

[0104] Here, after removing the third substrate, step S109 may further include: thinning the third type of light emitting layer 302. In addition, after removing the third substrate or thinning the third type of light emitting layer 302, refer to Fig.36 , step S109 further includes: forming a micro-gap structure 06 in the third type light emitting layer 302. The micro-gap structure 06 can be formed using a process similar to the above-described process of forming the micro-gap structure 06. Therefore, the process of forming the micro-gap structure 06 will not be repeatedly described.

[0105] Fig.36 Micro-gap structures 06 in first type light emitting layer 102 , second type light emitting layer 202 , and third type light emitting layer 302 are shown.

[0106] Return to reference Figure 30 to Figure 34 , the process after step S701 will be further described below.

[0107] In step S702, refer to Fig.31 , the third type light emitting layer 302 and the third metal layer 301 are patterned until a portion of the top of the second type light emitting layer 202 is exposed, thereby forming a stepped structure made of the third type light emitting layer 302 on the second type light emitting layer 202 .

[0108] More specifically, the step structure includes the third type light emitting layer 302 and the third metal layer 301. The process of patterning the third type light emitting layer 302 and the third metal layer 301 also includes: over-etching the top of the first type light emitting layer 102.

[0109] In step S703, refer to Fig.32 , the second type light emitting layer 202 and the second metal layer 201 are further patterned until a portion of the top of the first type light emitting layer 202 is exposed, thereby forming a stepped structure made of the second type light emitting layer 202 on the first type light emitting layer 102 .

[0110] More specifically, the step structure is made of the second type of light emitting layer 202 and the second metal layer 201. The patterning process can be performed by photolithography and plasma etching. The process of patterning the second type of light emitting layer 202 and the second metal layer 201 also includes: etching the top of the first type of light emitting layer 102. The parameters of the patterning process can be set according to actual needs and will not be limited here.

[0111] In step S704, refer to Fig.33 According to the preset first type of light-emitting area A01, the preset second type of light-emitting area A02 and the preset third type of light-emitting area A03, the third type of light-emitting layer 302, the third metal layer 301, the second type of light-emitting layer 202, the second metal layer 201, the first type of light-emitting layer 102 and the first metal layer 101 are etched, so as to divide the first type of light-emitting layer 102 in the first type of light-emitting area A01 from the first type of light-emitting layer in the second type of light-emitting area A02 and the third type of light-emitting area A03, divide the first metal layer 101 in the first type of light-emitting area A01 from the first metal layer in the second type of light-emitting area A02 and the third type of light-emitting area A03, divide the second type of light-emitting layer 202 in the second type of light-emitting area A02 from the second type of light-emitting layer in the third type of light-emitting area A03, and divide the second metal layer 201 in the second type of light-emitting area A02 from the second metal layer in the third type of light-emitting area A03. As a result of step S704, there are formed: a first type of LED 01 including a first segment 101-1 of a first metal layer and a first segment 102-1 of a first type of light-emitting layer; a second type of LED 02 including a second segment 101-2 of the first metal layer, a second segment 102-2 of the first type of light-emitting layer, a first segment 201-1 of the second metal layer and a first segment 202-1 of the second type of light-emitting layer; and a third type of LED 03 including a third segment 101-3 of the first metal layer, a third segment 102-3 of the first type of light-emitting layer, a second segment 201-2 of the second metal layer, a second segment 202-2 of the second type of light-emitting layer, a first segment 301-1 of the third metal layer and a first segment 302-1 of the third type of light-emitting layer.

[0112] Here, the etching process is performed by photolithography and etching process, and its parameters can be set according to actual needs.

[0113] According to the embodiment, as a result of step S704, a plurality of multi-color light-emitting pixel units are divided into each other according to a preset pixel unit array. Therefore, the light-emitting transistors in the pixel unit and / or the pixel unit array can be prepared through a division step, which simplifies the process and reduces the production cost, and especially promotes mass production.

[0114] In step S705, refer to Fig.34 A shared top electrode layer 05 serving as an extraction electrode for the first segment 201-1 of the second metal layer and an extraction electrode for the first segment 301-1 of the third metal layer is formed on top of the first segment 102-1 of the first type of light-emitting layer, the first segment 202-1 of the second type of light-emitting layer, and the first segment 302-1 of the third type of light-emitting layer.

[0115] Fig.37 is a display according to the embodiment of the present disclosure Fig.29 Flowchart of details of step S705 in FIG. Figures 38 to 40 It is displayed in Fig.37 A cross-sectional view of the structure formed in the steps shown in FIG. Fig.37 , step S705 further includes the following steps.

[0116] In step S501, refer to Fig.38 , a portion of the first segment 302-1 of the third type light emitting layer and a portion of the first segment 202-1 of the second type light emitting layer are removed, thereby exposing a portion of the first segment 201-1 of the second metal layer and a portion of the first segment 301-1 of the third metal layer.

[0117] In step S502, refer to Fig.39 A first electrical connector 203 is formed on the side walls and top of the first segment 201-1 of the second metal layer in the second type of light-emitting area A02, on the side walls of the second segment 102-2 of the first type of light-emitting layer, and on the side walls of the second segment 101-2 of the first metal layer, and a second electrical connector 303 is formed on the top and side walls of the first segment 301-1 of the third metal layer in the third type of light-emitting area A03, on the side walls of the second segment 202-2 of the second type of light-emitting layer, on the side walls of the second segment 201-2 of the second metal layer, on the side walls of the third segment 102-3 of the first type of light-emitting layer, and on the side walls of the third segment 101-3 of the first metal layer.

[0118] More specifically, refer to Fig.39The process of manufacturing the first electrical connector 203 and the second electrical connector 303 further includes the following steps. It should be noted that the following steps S5021 to S5023 are not shown in the drawings, but those skilled in the art can understand the steps S5021 to S5023 by referring to the steps S4021 to S4023 of the above embodiment.

[0119] In step S5021, a mask is formed on the substrate 100 to shield the area without the first electrical connector 203 and the second electrical connector 303, thereby exposing the top and side walls of the first segment 201-1 of the second metal layer, the side walls of the second segment 102-2 of the first type of light-emitting layer, and the side walls of the second segment 101-2 of the first metal layer in the second type of light-emitting area A02, and exposing the top and side walls of the first segment 301-1 of the third metal layer, the side walls of the second segment 202-2 of the second type of light-emitting layer, the side walls of the second segment 201-2 of the second metal layer, the side walls of the third segment 102-3 of the first type of light-emitting layer, and the side walls of the third segment 101-3 of the first metal layer in the third type of light-emitting area A03.

[0120] In step S5022 , after completing step S5021 , a conductive material is deposited on the substrate 100 .

[0121] In step S5023, refer to Fig.39 , remove the mask and the conductive material on the mask, thereby forming a first electrical connector 203 on the top and side walls of the first segment 201-1 of the second metal layer in the second type of light-emitting area A02, on the side walls of the second segment 102-2 of the first type of light-emitting layer, and on the side walls of the second segment 101-2 of the first metal layer, and forming a second electrical connector 303 on the top and side walls of the first segment 301-1 of the third metal layer in the third type of light-emitting area A03, on the side walls of the second segment 202-2 of the second type of light-emitting layer, on the side walls of the second segment 201-2 of the second metal layer, on the side walls of the third segment 102-3 of the first type of light-emitting layer, and on the side walls of the third segment 101-3 of the first metal layer.

[0122] The process of manufacturing the shared top electrode layer 05 will be further described below.

[0123] In step S503, refer to Fig.40 , an isolation layer 04 is formed to cover the first type light emitting area A01, the second type light emitting area A02, the third type light emitting area A03 and the exposed surface of the substrate 100. The isolation layer 04 has openings on the first segment 102-1 of the first type light emitting layer, the first segment 202-1 of the second type light emitting layer and the first segment 302-1 of the third type light emitting layer.

[0124] In step S504, refer again to Fig.34 After step S503, a continuous shared top electrode layer 05 is formed on the entire substrate 100. The shared top electrode layer 05 deposited in the opening is connected to the first segment 102-1 of the first type of light-emitting layer, the first segment 202-1 of the second type of light-emitting layer, and the first segment 302 of the third type of light-emitting layer.

[0125] As mentioned above, in the method for manufacturing a multi-color luminous pixel unit according to an embodiment of the present disclosure, since the film deposition process of each type of LED can be performed simultaneously, the LEDs can be prepared simultaneously without being prepared separately, thereby simplifying the process of manufacturing a multi-color luminous pixel unit and a micro-LED display panel, and promoting mass production. Due to the manufacturing method according to the embodiment of the present disclosure, different types of LEDs are arranged side by side on the same substrate, and the distance between them is short. Therefore, the size of the LED and the display panel made of the LED can be reduced. For example, the size of each LED can be 40 μm × 40 μm. In addition, the tops of different types of LEDs are not at the same level. That is, the heights of different types of LEDs are different, so that different types of light-emitting layers are exposed on the tops of different types of LEDs, thereby ensuring the light-emitting area and improving the light-emitting efficiency of each LED, and improving the integration of various LEDs. The micro-LED display panel formed by the pixel unit of the embodiment of the present disclosure has a clear picture display and high resolution. In addition, since the electrical connector connects each metal layer in the Mth type of LED, the Mth type of light-emitting layer (which is the top light-emitting layer) in the Mth type of LED can emit light, while the other light-emitting layers in the Mth type of LED are short-circuited due to the electrical connection of the metal layers arranged on both sides of each other light-emitting layer. For example, in the Mth type of LED, the first type of light-emitting layer is short-circuited due to the electrical connection of the first type of metal layer and the second type of metal layer arranged on both sides of the first type of light-emitting layer; the second type of light-emitting layer is short-circuited due to the electrical connection of the second type of metal layer and the third type of metal layer arranged on both sides of the second type of light-emitting layer; and so on. Therefore, various types of LEDs emit light separately without affecting each other. In addition, the micro gap in the light-emitting layer can release the stress inside the light-emitting layer and prevent it from warping without affecting the light-emitting efficiency of the light-emitting layer, thereby improving the product yield.

[0126] Fig.41 is a flow chart showing a method of manufacturing a micro LED display panel according to an embodiment of the present disclosure.

[0127] In step S4101, also refer to Fig.42(which is a cross-sectional view showing the structure formed in step S4101), a stacked structure including a first metal layer 101, a first type light emitting layer 102, a second metal layer 201, and a second type light emitting layer 202 is formed on the wafer substrate 500 in order from bottom to top. The process of forming the stacked structure on the wafer substrate 500 is similar to that of the reference Figure 11-Figure 21 The explained process of forming the stacked structure on the substrate 100. Therefore, the detailed explanation of step S4101 will not be repeated.

[0128] In step S4102, refer to Fig.43 (which is a cross-sectional view showing the structure formed in step S4102) and Fig.44 (which is a top view showing the structure formed in step S4102), a groove 600 is formed in the stacked structure. The groove 600 can be formed by etching from the top of the stacked structure to the bottom of the stacked structure until the wafer substrate 500 is exposed. The groove 600 defines a plurality of micro LED display panel areas 550 on the wafer substrate 500. Adjacent micro LED display panel areas 550 are separated from each other by the grooves 600 formed therebetween. The plurality of micro LED display panel areas 550 are used to form a plurality of micro LED display panels.

[0129] In step S4103, refer to Fig.45 (This is after executing step S4103 Fig.43 The second type of light emitting layer 202 and the second metal layer 201 on the entire wafer substrate 500 are patterned (i.e., selectively etched) until a portion of the top surface of the first type of light emitting layer 102 is exposed, thereby forming a plurality of step structures on the entire wafer substrate 500. The process performed in step S4103 is similar to the process performed in step S602, and its reference Figure 8 Therefore, detailed explanation of step S4103 will not be repeated. During the etching process in step S4103, stress generated by etching may be released via the groove 600, thereby preventing the wafer substrate 500 from being warped due to stress.

[0130] In step S4104, refer to Fig.46(which is a cross-sectional view showing the M portion after executing step S4104), the second type light emitting layer 202, the second metal layer 201, the first type light emitting layer 102, and the first metal layer 101 on the entire wafer substrate 500 are selectively etched to expose the side surface of the first metal layer 101. As a result of executing step S4104, a plurality of first type LEDs 01 and a plurality of second type LEDs 02 are formed in each micro LED display panel region 550. Each first type LED 01 includes a first segment 101-1 of the first metal layer and a first segment 102-1 of the first type light emitting layer. Each second type LED 02 includes a second segment 101-2 of the first metal layer, a second segment 102-2 of the first type light emitting layer, a first segment 201-1 of the second metal layer, and a first segment 202-1 of the second type light emitting layer. The process performed in step S4104 is similar to the process performed in step S603, and reference is made thereto. Fig. 9 Therefore, detailed explanation of step S4104 will not be repeated. During the etching process in step S4104, stress generated by etching may be released via the groove 600, thereby preventing the wafer substrate 500 from being warped due to stress.

[0131] In step S4105, refer to Fig.47 (which is a cross-sectional view of the M portion after the step S4105 is performed), in each second type LED 02, an electrical connector for electrically connecting the second segment 101-2 of the first metal layer and the first segment 201-1 of the second metal layer is formed. In addition, in each micro LED display panel area 550, a shared top electrode layer 05 (which serves as an extraction electrode of the second metal layer 201) is formed on the top of the first segment 102-1 of the first type of light emitting layer in the plurality of first type LEDs 01 and on the top of the first segment 202-1 of the second type of light emitting layer in the plurality of second type LEDs 02. The process performed in step S4105 is similar to the process performed in step S604, and its reference is made to FIG. Fig.10 and Figure 22-28 Therefore, the detailed explanation of step S4105 will not be repeated.

[0132] In step S4106, refer to Fig.48 (which is a top view showing the structure formed in step S4106), the wafer substrate 500 having the structure formed in steps S4101 to S4105 is arranged along Fig.44 The grooves 600 shown in FIG. 5 are cut through the wafer substrate 500 to form a plurality of micro LED display panels 650 .

[0133] As mentioned above, in the method of manufacturing a micro LED display panel according to an embodiment of the present disclosure, a groove is formed in the stack structure before etching the stack structure. Therefore, the stress generated during the etching process of the stack structure can be released via the groove, thereby preventing the wafer substrate from warping due to the stress. Therefore, the quality of the micro LED display panel can be improved.

[0134] While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A method for manufacturing a micro light emitting diode (LED) display panel, the method comprising: forming a stacked structure on a wafer substrate, the stacked structure including, in order from bottom to top, a first metal layer, a first type of light emitting layer, a second metal layer, and a second type of light emitting layer; forming a plurality of grooves in the stacked structure, the plurality of grooves defining a plurality of micro LED display panel areas; patterning the second type of light emitting layer and the second metal layer until a portion of a top surface of the first type of light emitting layer is exposed; After patterning the second type of light emitting layer and the second metal layer, selectively etching the stacked structure to expose the side surface of the first metal layer, thereby forming a plurality of first LEDs and a plurality of second LEDs in each of the micro LED display panel regions, each of the first LEDs including the first metal layer and the first type of light emitting layer, and each of the second LEDs including the first metal layer, the first type of light emitting layer, the second metal layer, and the second type of light emitting layer; as well as The wafer substrate is cut to form a plurality of micro LED display panels.

2. The method of claim 1, wherein: Forming the stacked structure on the wafer substrate includes: forming the first metal layer and the first type of light-emitting layer in sequence on the wafer substrate; forming a first metal bonding layer on top of the first type of light emitting layer; forming the second type of light emitting layer and the second metal bonding layer on the first substrate from bottom to top; bonding the first metal bonding layer and the second metal bonding layer to form the second metal layer; and The first substrate is removed.

3. The method of claim 2, wherein: Forming the first metal layer and the first type of light-emitting layer from bottom to top on the wafer substrate includes: forming a third metal bonding layer on the wafer substrate; forming the first type of light emitting layer and a fourth metal bonding layer on the second substrate from the first substrate from bottom to top; bonding the third metal bonding layer and the fourth metal bonding layer to form the first metal layer; and The second substrate is removed.

4. The method of claim 2, further comprising: Prior to forming the first metal bonding layer on top of the first type of light emitting layer, the first type of light emitting layer is thinned.

5. The method of claim 2, further comprising: The second type of light emitting layer is thinned.

6. The method of claim 2, further comprising: A micro-gap structure is formed in at least one of the first type light emitting layer or the second type light emitting layer.

7. The method of claim 2, further comprising: forming a micro-gap structure in both the first type of light-emitting layer and the second type of light-emitting layer, The micro-gap structure in the first type of light-emitting layer is offset relative to the micro-gap structure in the second type of light-emitting layer.

8. The method of claim 1, further comprising: The first metal layer and the second metal layer in at least one of the second LEDs are electrically connected.

9. The method of claim 8, wherein: The electrically connecting the first metal layer and the second metal layer in at least one of the second LEDs comprises: removing a portion of the second type light emitting layer in the second LED to expose a top portion of the second metal layer in the second LED; and Electrical connectors are formed on the exposed top portion and sidewalls of the second metal layer in the second LED and on the sidewalls of the first type of light emitting layer and the first metal layer in the second LED.

10. The method of claim 1, further comprising: A top electrode layer is formed on top of at least one first LED and at least one second LED in each micro LED display panel region.

11. The method of claim 10, further comprising: forming an isolation layer covering at least one first LED and at least one second LED; forming a first opening and a second opening in the isolation layer, the first opening exposing a portion of a first type of light emitting layer in the first LED, and the second opening exposing a portion of a second type of light emitting layer in the second LED; as well as The top electrode layer is formed on the wafer substrate, the top electrode layer contacts a first type of light emitting layer in the first LED via the first opening and contacts a second type of light emitting layer in the second LED via the second opening.

12. The method of claim 1, wherein: The stacked structure further includes a third metal layer formed on top of the second type of light emitting layer and a third type of light emitting layer formed on top of the third metal layer, The method further includes patterning the third type of light emitting layer and the third metal layer until a portion of the second type of light emitting layer is exposed, and The selectively etching the stacked structure further includes selectively etching the stacked structure to form the plurality of first LEDs, the plurality of second LEDs, and a plurality of third LEDs, each third LED including the first metal layer, the first type of light-emitting layer, the second metal layer, the second type of light-emitting layer, the third metal layer, and the third type of light-emitting layer.

13. The method of claim 12, wherein: Forming the stacked structure on the wafer substrate includes: forming the first metal layer, the first type of light-emitting layer, the second metal layer, and the second type of light-emitting layer on the wafer substrate from bottom to top; forming a first metal bonding layer on the second type of light emitting layer; forming the third type of light emitting layer and a second metal bonding layer on the substrate from bottom to top of the substrate; bonding the first metal bonding layer and the second metal layer to form the third metal layer; and The substrate is removed.

14. The method of claim 12, further comprising: At least one of the first type of light emitting layer, the second type of light emitting layer, or the third type of light emitting layer is thinned.

15. The method of claim 12, further comprising: A micro-gap structure is formed in at least one of the first type light emitting layer, the second type light emitting layer, or the third type light emitting layer.

16. The method of claim 12, further comprising: forming a micro-gap structure in all of the first type light-emitting layer, the second type light-emitting layer, and the third type light-emitting layer, wherein the microgap structure in the first type of light-emitting layer is staggered relative to the microgap structure in the second type of light-emitting layer, and The micro-gap structure in the second type of light-emitting layer is staggered relative to the micro-gap structure in the third type of light-emitting layer.

17. The method of claim 12, further comprising: The first metal layer and the second metal layer in at least one of the second LEDs are electrically connected, and the first metal layer, the second metal layer, and the third metal layer in each of the third LEDs are electrically connected.

18. The method of claim 17, wherein: The electrically connecting the first metal layer and the second metal layer in at least one of the second LEDs, and the electrically connecting the first metal layer, the second metal layer, and the third metal layer in at least one of the third LEDs comprises: removing a portion of the second type of light emitting layer in the second LED to expose a top portion of the second metal layer in the second LED; removing a portion of a third type of light emitting layer in the third LED to expose a top portion of a third metal layer in the third LED; forming a first electrical connector on the exposed top and sidewalls of the second metal layer in the second LED and on the sidewalls of the first type of light emitting layer and the first metal layer in the second LED; and A second electrical connector is formed on the exposed top and sidewalls of the third metal layer in the third LED and on the second type of light emitting layer, the second metal layer, the first type of light emitting layer, and the sidewalls of the first metal layer in the third LED.

19. The method of claim 12, further comprising: A top electrode layer is formed on top of at least one first LED, at least one second LED, and at least one third LED in each micro LED display panel region.

20. The method of claim 19, further comprising: forming an isolation layer covering at least one first LED, at least one second LED, and at least one third LED; forming a first opening, a second opening, and a third opening in the isolation layer, the first opening exposing a portion of a first type of light emitting layer in the first LED, the second opening exposing a portion of a second type of light emitting layer in the second LED, and the third opening exposing a portion of a third type of light emitting layer in the third LED; as well as The top electrode layer is formed on the wafer substrate, and the top electrode layer contacts the first type of light-emitting layer in the first LED via the first opening, contacts the second type of light-emitting layer in the second LED via the second opening, and contacts the third type of light-emitting layer in the third LED via the third opening.

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