Preparation method of display device

Abstract

The invention relates to the technical field of display, in particular to a preparation method of a display device, and aims to solve the technical problem of how to prepare a display device capable of meeting high-frequency and high-voltage driving occasion application. In the method, firstly, an epitaxial layer in a substrate is etched and divided into a plurality of array distribution areas; each area is divided into a light-emitting area and a driving area, the light-emitting area is used for preparing a luminous body, the driving area is used for preparing a transistor, the transistor and the luminous body share an N-type GaN material of an epitaxial layer, during preparation, the transistor and the luminous body are prepared and formed in the corresponding area of the N-type GaN material by adopting a proper process, bonding is not needed, and the preparation process is greatly simplified.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a method for preparing a display device. Background Art

[0002] Micro / Mini LED is a current-driven light-emitting device, and there are generally two driving modes: passive addressing drive (PM: passive matrix, also known as passive addressing drive) and active addressing drive (AM: active matrix, also known as active addressing drive). When using active addressing drive, each Micro / Mini LED has its corresponding independent driving circuit, and the driving current is provided by the driving transistor.

[0003] In order to facilitate the active site selection drive of Micro / Mini LED, Micro / Mini LED and driving transistor are often integrated. At present, in the integrated structure of Micro / Mini LED and driving transistor, the commonly used driving transistor is SiC transistor, which has the following defects: (1) Integration of heterogeneous materials, complex process. In this structure, the material used to prepare Micro / Mini LED is GaN-based material, while the main material of the driving transistor is SiC. The two need to be integrated using a bonding process. The bonding process has high requirements for temperature and pressure, and is prone to problems such as low bonding yield and high process difficulty. (2) Compared with GaN materials, SiC materials have lower electron mobility and narrower bandgap, which is not conducive to the application of Micro / Mini LED in high-frequency and high-voltage occasions.

[0004] GaN-based materials have excellent electrical properties such as high electron mobility and wide bandgap. The driving transistor prepared using this material can achieve high-frequency and high-voltage driving. Therefore, the monolithic homogeneous integration of LEDs and driving transistors on the same epitaxial wafer containing GaN materials has become one of the preferred solutions for technical personnel in this field to achieve the integrated integration of Micro / Mini LEDs and driving transistors. Summary of the invention

[0005] The present application provides a method for preparing a display device, by which a display device that can meet the application requirements of high-frequency and high-voltage driving occasions is prepared.

[0006] The technical solutions adopted in this application are as follows: A method for preparing a display device, characterized in that the method comprises: providing a substrate, on which an epitaxial layer is arranged, wherein the epitaxial layer at least comprises an undoped GaN layer and a first-type GaN layer sequentially distributed from bottom to top, wherein the first-type GaN layer comprises N-type GaN; Etching the epitaxial layer to divide the epitaxial layer into a plurality of array distribution areas; Divide each area into a light-emitting area and a driving area; A light-emitting body is prepared in the light-emitting area, and a transistor is prepared in the driving area. The transistor is electrically connected to the corresponding light-emitting body through the first-type GaN layer to control the turning on or off of the light-emitting body to obtain a light-emitting module.

[0007] Its further characteristic is that The epitaxial layer also includes a light-emitting layer and a second-type GaN layer.

[0008] Furthermore, the second-type GaN layer includes P-type GaN, and the light-emitting layer is a quantum well layer.

[0009] Furthermore, the epitaxial layer is etched by photolithography and etching process to form a plurality of channels, thereby dividing the epitaxial layer into a plurality of array distribution areas.

[0010] Furthermore, a light-emitting body is prepared in the light-emitting area, and a transistor is prepared in the driving area, including: using a photolithography and etching process to etch a local area of ​​the epitaxial layer, the etching depth reaches a local area of ​​the first-type GaN layer, and forms a first etching groove and an array of protrusions, wherein the protrusions are the light-emitting body; Using a photolithography and etching process, etching the first-type GaN layer at the bottom of the first etching groove to form a second etching groove; Using photolithography, deposition and stripping processes, a patterned source electrode and a patterned drain electrode are prepared on the surface of the first-type GaN layer at the bottom of the first etched groove, and the source electrode and the drain electrode are distributed on both sides of the second etched groove and are electrically connected to the first-type GaN layer below both sides of the second etched groove respectively; Using chemical vapor deposition or atomic layer deposition, the first insulating material is covered in the second etching groove and the entire surface including the source and drain surfaces to form a first insulating layer; A patterned gate is prepared on the upper surface of the first insulating layer by using photolithography, deposition and stripping processes.

[0011] Further, preparing the P electrode includes: using chemical vapor deposition or atomic layer deposition to cover the entire surface including the gate surface and the light-emitting body surface with a second insulating material to form a second insulating layer; Using photolithography and etching processes, opening holes in the second insulating layer and local areas of the first insulating layer to expose local areas of the second-type GaN layer; A P electrode is prepared above the light-emitting body by using photolithography, deposition and stripping processes, and the bottom of the P electrode sequentially penetrates the second insulating layer, the opening in the first insulating layer, and is electrically connected to a local area of ​​the second-type GaN layer.

[0012] Furthermore, a third insulating layer is formed by covering the entire surface including the surface of the P electrode with a third insulating material using a chemical vapor deposition method or an atomic layer deposition method.

[0013] Furthermore, a phosphor material is coated on the entire surface including the surface of the third insulating layer to form a phosphor layer, and the phosphor layer is used to convert the light color emitted by the light emitter into white.

[0014] Furthermore, a first color filter is arranged on the surface of the phosphor layer, and the first color filter corresponds to the light emitting surface of the light emitting body one by one, and is used for converting white into at least three primary colors: red, green, and blue.

[0015] Furthermore, a second color filter is arranged on the entire surface including the surface of the third insulating layer, and the second color filter corresponds to the light emitting surface of the light emitting body one by one, and is used to convert the light color emitted by the light emitting body into at least three primary colors: red, green, blue

[0016] Furthermore, a black material is filled in a gap between two adjacent first color filters or between two adjacent second color filters to form a contrast enhancement layer.

[0017] Furthermore, the first insulating material, the second insulating material, and the third insulating material include but are not limited to at least one of SiO2 and SiNx.

[0018] The above-mentioned scheme of the present invention can achieve the following beneficial effects: in the display device prepared by the method of the present application, the transistor and the light-emitting body share the N-type GaN material of the epitaxial layer. During the preparation, a suitable process is used to prepare the transistor and the light-emitting body in the corresponding area of ​​the N-type GaN material without bonding, which greatly simplifies the preparation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the cross-sectional structure of a single pixel unit of the present application; Figure 2 This is a schematic diagram of the top view of the display device of the present application; Figure 3 is a schematic cross-sectional structural diagram of a single pixel unit in another embodiment of the present application; Figure 4 This is a schematic diagram of the cross-sectional structure of the substrate and the epitaxial layer in the method for preparing the display device of the present application; Figure 5This is a schematic diagram of a cross-sectional structure after a channel is formed in the method for preparing a display device of the present application; Figure 6 This is a schematic diagram of the cross-sectional structure after the first etching groove and the light-emitting body are formed in the display device manufacturing method of the present application; Figure 7 This is a schematic diagram of the cross-sectional structure after the second etching groove is formed in the method for preparing the display device of the present application; Figure 8 This is a schematic diagram of the cross-sectional structure after the source and drain are formed in the method for preparing the display device of the present application; Fig. 9 This is a schematic diagram of the cross-sectional structure after the first insulating layer and the gate are formed in the display device manufacturing method of the present application; Fig.10 This is a schematic diagram of the cross-sectional structure after the second insulating layer and the P electrode are formed in the display device manufacturing method of the present application; Fig.11 This is a schematic cross-sectional structure diagram after the third insulating layer is formed in the method for preparing a display device of the present application; Fig.12 It is a schematic diagram of the cross-sectional structure after the phosphor layer is formed in the display device preparation method of the present application.

[0020] Reference numerals: substrate 1, non-doped GaN layer 2, light emitter 3, transistor 4, first insulating layer 5, second insulating layer 6, third insulating layer 7, phosphor layer 8, first color filter 9, contrast enhancement layer 10, second color filter 11, channel 12, first etching groove 13, second etching groove 14; A first connection line 101, a second connection line 102, a third connection line 103, a fourth connection line 104, a first solder pad 201, a second solder pad 202, a third solder pad 203, and a fourth solder pad 204; Source 401 , drain 402 , gate 403 , first-type GaN layer 301 , light-emitting layer 302 , second-type GaN layer 303 , and P-electrode 304 . DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0022] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or equipment comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment.

[0023] The following discloses a specific embodiment of a method for manufacturing a display device. The method includes the following specific steps: S1. providing a substrate 1. In this embodiment, the substrate 1 is a sapphire substrate.

[0024] An epitaxial layer is provided on the substrate 1, and the epitaxial layer includes an undoped GaN layer 2, a first-type GaN layer 301, a light-emitting layer 302, and a second-type GaN layer 303, which are sequentially distributed from bottom to top; in this embodiment, the first-type GaN layer 301 is an N-type GaN layer, the second-type GaN layer 303 is a P-type GaN layer, and the light-emitting layer 302 is a quantum well layer. Figure 4 .

[0025] S2. Using a photolithography and etching process, a number of channels are etched in the epitaxial layer to divide the epitaxial layer into a number of array distribution areas. Specifically: S21, coating a first photoresist on the surface of the second-type GaN layer 303; S22, exposing the first photoresist based on the first mask; S23, developing to expose the to-be-etched area of ​​the epitaxial layer; S24, using dry etching or wet etching to etch the to-be-etched area of ​​the epitaxial layer to form a channel 12, wherein the channel 12 penetrates the non-doped GaN layer 3 and divides the epitaxial layer into a plurality of array distribution areas; S25, cleaning to remove the remaining first photoresist, refer to Figure 5 .

[0026] S3. Divide each area into a light-emitting area and a driving area.

[0027] S4, preparing a light-emitting body 3 in the light-emitting area, and preparing a transistor 4 in the driving area, including: S41, using a photolithography and etching process to etch a local area of ​​the epitaxial layer, and the etching depth reaches a local area of ​​the first-type GaN layer 301 to form a first etching groove 13 and a bump, the bump is the light-emitting body 3, specifically: S411, coating a second photoresist on the entire surface including the surface of the second-type GaN layer; S412, exposing the second photoresist based on the second mask; S413, developing to expose the area to be etched in each area; S414, using dry etching or wet etching to etch the area to be etched in each area to form a first etching groove 13 and a bump, where the bump is the light-emitting body 3; In this step, the first-type GaN layer 301 is etched into a convex shape, including a horizontally distributed connection portion and a convex portion protruding from the top of the connection portion. One side of the connection portion is the area where the transistor 4 is located, and the convex portion is the area where the light-emitting body 3 is located.

[0028] S415, cleaning and removing the residual second photoresist, reference Figure 6 .

[0029] S42, using a photolithography and etching process, etching the first-type GaN layer 301 below the first etching groove 13 to form a second etching groove 14, specifically: S421, coating a third photoresist on the entire surface including the surface of the luminous body; S422, exposing the third photoresist based on the third mask; S423, developing to expose the to-be-etched area of ​​the first-type GaN layer below the first etching groove 13; S424, using dry etching or wet etching to etch the to-be-etched area of ​​the first-type GaN layer below the first etching groove 13 to form a second etching groove 14; S425, cleaning and removing the residual third photoresist, reference Figure 7 .

[0030] S43, using photolithography, deposition and stripping processes, a patterned source and a patterned drain are prepared on the surface of the first-type GaN layer 301, the source and the drain are distributed on both sides of the second etched groove 14, and are electrically connected to the connection parts of the first-type GaN layer 301 below the two sides of the second etched groove 14, specifically, S431, coating a fourth photoresist on the inner surface of the first etching groove 13, the inner surface of the second etching groove 14 and the entire surface including the surface of the second GaN layer 303; S432, exposing and developing the fourth photoresist based on the fourth mask; S433. Deposit a conductive material on the surface of the fourth photoresist by electron beam evaporation or magnetron sputtering. In this embodiment, the conductive material includes but is not limited to titanium, chromium, aluminum, nickel, gold, silver, and platinum, preferably titanium, aluminum, nickel, and gold, or chromium, aluminum, nickel, and gold. In this embodiment, Ti / Al / Ti / Ni / Ti / Au are stacked in sequence, or Cr / Al / Cr / Ni / Cr / Au are stacked in sequence, wherein Ti and Cr are used as adhesion materials, and Al, Au, Ni, etc. are used as conductive layers.

[0031] S434, based on the developed pattern, stripping the conductive material to obtain a patterned source electrode and a patterned drain electrode; S435, cleaning and removing the remaining fourth photoresist, reference Figure 8 .

[0032] S44 , using chemical vapor deposition or atomic layer deposition (ie, CVD or ALD) to grow a first insulating material in the second etching groove 14 and on the entire surface including the source 401 and the drain 402 , to form a first insulating layer 5 .

[0033] S45, using photolithography, deposition and stripping processes to prepare a patterned gate 403 on the first insulating layer 5, specifically, S451, coating a fifth photoresist on the entire surface including the surface of the first insulating layer; S452, exposing and developing the fifth photoresist based on the fifth mask; S453. Deposit a conductive material on the surface of the fifth photoresist by electron beam evaporation or magnetron sputtering. In this embodiment, the conductive material includes but is not limited to titanium, chromium, aluminum, nickel, gold, silver, and platinum, preferably titanium, aluminum, nickel, and gold, or chromium, aluminum, nickel, and gold. In this embodiment, Ti / Al / Ti / Ni / Ti / Au are stacked in sequence, or Cr / Al / Cr / Ni / Cr / Au are stacked in sequence, wherein Ti and Cr are used as adhesion materials, and Al, Au, Ni, etc. are used as conductive layers.

[0034] S454 , based on the developed pattern, the conductive material is stripped to obtain a patterned gate 403 .

[0035] S455, cleaning and removing the residual fifth photoresist, reference Fig. 9 .

[0036] S5. Using chemical vapor deposition or atomic layer deposition (ie, CVD or ALD), grow a second insulating material on the entire surface including the gate surface and the surface of the first insulating layer to form a second insulating layer 6.

[0037] It should be noted that, in another embodiment, the second insulating layer may not be provided. After the gate 403 is prepared through the above steps S1 to S4, a photolithography and etching process is used to directly open a hole in the first insulating layer in the area where the P electrode is to be prepared, and a photolithography, deposition and stripping process is used to form a P electrode at the opening. Then, the third insulating layer, the phosphor layer, the first color filter, and the contrast enhancement layer are prepared in sequence. This is conducive to further simplifying the preparation process.

[0038] S6, using photolithography and etching processes, etching the second insulating layer 6 and the local area of ​​the first insulating layer 5 to form a third etching groove, exposing the area to be contacted of the second-type GaN layer, that is, making a P electrode opening above the light-emitting body, specifically, S61, coating a sixth photoresist on the entire surface including the surface of the second insulating layer; S62, exposing the sixth photoresist based on the sixth mask; S63, developing to expose partial areas of the second insulating layer 6 and the first insulating layer 5; S64, using dry etching or wet etching to sequentially etch the second insulating layer 6 and the local area of ​​the first insulating layer 5 to form a third etching groove.

[0039] S65, cleaning and removing the remaining sixth photoresist.

[0040] S7, using photolithography, deposition and stripping processes, preparing a P electrode 304 on the top of the light-emitting body, the bottom end of the P electrode 304 passes through the third etching groove and is electrically connected to the second-type GaN layer 303, specifically, S71, coating a seventh photoresist on the entire surface including the surface of the second insulating layer 6; S72, exposing and developing the seventh photoresist based on the seventh mask; S73. Deposit a conductive material on the surface of the seventh photoresist and in the third etching groove by electron beam evaporation or magnetron sputtering. In this embodiment, the conductive material includes but is not limited to titanium, chromium, aluminum, nickel, gold, silver, and platinum, preferably titanium, aluminum, nickel, and gold, or chromium, aluminum, nickel, and gold. In this embodiment, Ti / Al / Ti / Ni / Ti / Au are stacked in sequence, or Cr / Al / Cr / Ni / Cr / Au are stacked in sequence, wherein Ti and Cr are used as adhesion materials, and Al, Au, Ni, etc. are used as conductive layers.

[0041] S74, based on the developed pattern, the conductive material is stripped to obtain a patterned P electrode.

[0042] S75, cleaning and removing the remaining sixth photoresist, reference Fig.10 .

[0043] S8, using chemical vapor deposition or atomic layer deposition (ie, CVD or ALD) to grow a third insulating material on the entire surface including the surface of the P electrode to form a third insulating layer 7, referring to Fig.11 .

[0044] S9, using screen printing technology to coat the entire surface including the surface of the third insulating layer 7 with a phosphor material, and solidifying the phosphor material to form a phosphor layer 8, referring to Fig.12 .

[0045] S10, disposing a first color filter 9 on the surface of the phosphor layer, wherein the first color filter 9 comprises a plurality of light color conversion areas, and the light color conversion areas correspond one to one with the light emitting surfaces of the light emitter.

[0046] S11, filling the gap between two adjacent light color conversion areas with black material to form a contrast enhancement layer 10, referring to Figure 1 .

[0047] In the above steps S44, S5, and S8, the first insulating material, the second insulating material, and the third insulating material include but are not limited to at least one of SiO2 and SiNx, and SiO2 is preferred in this embodiment.

[0048] In the display device prepared by the above method, the transistor and the light-emitting body share the N-type GaN material of the epitaxial layer. The GaN-based material has electrical properties such as high electron mobility and wide bandgap width. The driving transistor prepared by this material can realize high-frequency and high-voltage driving of the light-emitting body, thereby meeting the high-frequency and high-voltage application requirements of the display device. In addition, in the above-mentioned preparation process of the present application, the array-distributed light-emitting body is obtained by photolithography, etching, etc., without the need for mass transfer, avoiding a series of problems such as low transfer accuracy caused by mass transfer; no bonding is required, simplifying the preparation process.

[0049] The specific structure is as follows: The display device includes a substrate 1, a light-emitting module distributed on the same surface of the substrate, and a non-doped GaN layer 2. The substrate 1, the non-doped GaN layer 2, and the light-emitting module are distributed in sequence from bottom to top. Figure 1 , wherein the substrate 1 is sapphire.

[0050] The light-emitting module has a substrate distributed in an array structure, and each light-emitting module includes a group of light-emitting bodies 3 and transistors 4. The transistors 4 are electrically connected to the light-emitting bodies 3 and are used to control the on or off of the light-emitting bodies 3. In this case, the transistors 4 and the light-emitting bodies 3 in the same light-emitting module share a first-type GaN layer 301. The first-type GaN layer 301 is convex, including a horizontally distributed connection portion and a convex portion protruding from the top of the connection portion. The convex portion is located below the light-emitting body and constitutes a part of the light-emitting body. The connection portion extends from the transistor to the light-emitting body and is used to electrically connect the transistor to the light-emitting body.

[0051] The specific structures of transistor 4 and light emitting body 3 are as follows: The transistor 4 is a GaN transistor, including a source 401, a drain 402, a gate 403, a first insulating layer 5, and a connection portion of the first-type GaN layer 301, wherein the source 401 and the drain 402 are distributed above one side of the connection portion, and the bottom ends are electrically connected to one side of the connection portion respectively, and the first insulating layer 5 covers the surface of the source 401 and the drain 402, and the bottom end thereof penetrates the connection portion to separate the source 401 and the drain 402. The gate 403 is located at the top of the first insulating layer 5, and is separated from the source 401 and the drain 402 by the first insulating layer 5.

[0052] The light-emitting body 3 includes a convex portion of a first-type GaN layer 301, a light-emitting layer 302, a second-type GaN layer 303, an N electrode, and a P electrode 304, which are distributed in sequence from bottom to top. The first-type GaN layer below the convex portion is the N electrode. In this embodiment, the N electrode is electrically connected to the drain 402 of the transistor 4 through a connecting portion to form a common cathode structure; the second-type GaN layer 303 is a P-type GaN layer, and the P electrode 304 is located above the second-type GaN layer 303 and is electrically connected to the second-type GaN layer 303.

[0053] In the above structure, the first-type GaN layer 303 is set to be convex, which facilitates the electrical connection between the transistor 4 and the light-emitting body 3. In addition, the common cathode structure is located at the bottom of the light-emitting body 3 and the transistor 4, which will not affect the light emission from the side or top of the light-emitting body, and is conducive to improving the light extraction efficiency. In addition, the transistor 4 and the light-emitting body 3 share the epitaxial layer N-type GaN material. During preparation, the transistor 4 and the light-emitting body 3 can be prepared in the corresponding area of ​​the N-type GaN material by using a suitable process, without the need for secondary epitaxial growth, which simplifies the preparation process.

[0054] In order to avoid electrical interference between two adjacent light-emitting bodies 3, a second insulating layer 6 and a third insulating layer 7 are also provided in the display device, wherein the second insulating layer 6 covers the entire surface including the gate surface and the first insulating layer surface, and the third insulating layer 7 covers the entire surface including the P electrode surface and the second insulating layer surface.

[0055] In the present application, the illuminant 3 is a blue LED chip, and the blue LED chip is a Mini LED chip or a Micro LED chip. In order to obtain colored light, a light color conversion unit is arranged on the light emitting surface of the blue LED chip, and the light color conversion unit includes a phosphor layer 8, a first color filter 9, a third insulating layer 7, a phosphor layer 8, and a first color filter 9, which are arranged in sequence from bottom to top.

[0056] In this embodiment, the phosphor layer 8 covers the surface of the third insulating layer above the light-emitting body 3, and is used to convert the blue light emitted by the blue LED chip into white. In addition, the phosphor layer 8 is also filled above the transistor 4, so that the light-emitting module forms a horizontal flat surface, which is convenient for the installation and process packaging of the first color filter 9 in the subsequent process.

[0057] In addition, in the present embodiment, the first color filter 9 includes a color conversion area and a gap arranged between the color conversion areas. The color conversion area corresponds to the light emitting surface of the light emitting body 3 one by one, and is used to convert the white light into three primary colors: red, green, and blue. The light emitting areas corresponding to red, green, and blue are respectively a red light area, a green light area, and a blue light area. The red light area, the green light area, and the blue light area are arranged in sequence from left to right to form a pixel unit, or the red light area, the green light area, and the blue light area are arranged in sequence in the horizontal direction to form a pixel unit, and at the same time, the red light area, the green light area, and the blue light area are arranged in sequence in the column direction to form a pixel unit.

[0058] The gap is located above the transistor 4 and is filled with a black or gray material, preferably a black material. The black material is solidified to form a contrast enhancement layer 10 for enhancing display contrast.

[0059] It should be noted that, in another embodiment, the light color conversion unit includes a second color filter 11, that is, the second color filter 11 is directly arranged on the surface where the light emitting surface of the blue light LED chip is located, and the second color filter 11 also includes a color conversion area and a gap arranged between the color conversion areas. The color conversion areas correspond to the light emitters one by one, and are used to convert the blue light emitted by the three blue light LED chips in the same pixel unit into red light, green light, and blue light respectively. The corresponding areas are the red light area, the green light area, and the blue light area, which are arranged in sequence from left to right to form a pixel unit (reference Figure 3 ), or, the red light area, the green light area, and the blue light area are sequentially spaced apart in the horizontal direction to form a pixel unit, and at the same time, the red light area, the green light area, and the blue light area are sequentially spaced apart in the column direction to form a pixel unit.

[0060] The first color filter and the second color filter both have a red light emitting area, a green light emitting area, and a blank transparent area arranged in the same manner as the light-emitting body array, and the light emitting area includes materials such as perovskite or quantum dots. Compared with the light color conversion method of directly converting blue light into red light, green light, and blue light through the second color filter, the above-mentioned embodiment of the present application first converts blue light into white light through the phosphor layer, and the phosphor layer has a certain light uniformity effect, which is conducive to improving the brightness uniformity, and then converting white light into red light, green light, and blue light through the first color filter is more conducive to improving the light color uniformity of the display device.

[0061] In addition, the light-emitting modules are distributed in an array structure. In order to facilitate the connection of the light-emitting modules in the middle of the substrate with an external power supply, the present application also provides a first connecting line 101, a second connecting line 102, a third connecting line 103, a fourth connecting line 104, a first soldering pad 201, a second soldering pad 202, and a third soldering pad 203 in the display device. Figure 2, the first pads 201 are staggered along the row edges of the upper and lower sides of the substrate, the second pads 202 are staggered along the column edges of the left and right sides of the substrate, and the third pads 203 are located in the four corner areas of the substrate 1; the first connecting wires 201 are spaced along the substrate column direction, electrically connecting the source electrodes 401 of the light-emitting modules in the same column, one end of which extends to the row edge of the substrate 1 and is electrically connected to the first pads 201, and the first pads are used to connect the negative electrode of the external power supply; the second connecting wires 102 are spaced along the substrate row direction, electrically connecting the gate electrodes 403 of the light-emitting modules in the same row, one end of which extends to the column edge of the substrate 1 and is electrically connected to the second pads 202; the third connecting wires 103 are spaced along the substrate row direction, connecting the P electrodes 304 of the light-emitting modules in the same row, one end of which extends to the column edge of the substrate 1 and is electrically connected to the fourth connecting wire 104. The fourth connecting wire 104 is distributed along the four edges of the substrate 1, and is electrically connected to the positive electrode of the external power supply through the third pads 203 in the two or four corner areas.

[0062] The staggered distribution of the first pad and the second pad in the present application reduces the number of pads on a single side of the display device, which is beneficial for expanding the size of the pad without reducing the effective area of ​​the display device. This is especially beneficial for improving the accuracy of subsequent connection of the display device with other devices or external circuits when the display device corresponds to a large number of pins on a packaging substrate.

[0063] When displaying, the third pad is used as the input end, the first pad is used as the output end, the positive voltage is input to the P electrode 304 of the light-emitting body by the third pad 203, the fourth connection line 104, and the third connection line 103, and at the same time, the external control signal is transmitted to the gate 403 through the second pad 202 and the second connection line 102 to control the conduction and opening time of the transistor, and the current signal is transmitted to the P electrode of the light-emitting body through the third pad 203, the fourth connection line 104, and the third connection line 103 in sequence, and is transmitted to the N-type G through the P electrode, the P-type GaN layer, and the light-emitting layer. aN layer, and then transmitted to the transistor drain by the N-type GaN layer. At this time, the source and drain of the transistor are in the on state. Therefore, the current is output through the transistor drain, source, first connecting line, and first pad, thereby forming a current loop. When the current passes through the light-emitting body, the light-emitting layer inside the light-emitting body is stimulated to emit light. In this embodiment, the light-emitting body is a blue light LED chip, and the blue light emitted by it produces white light under the action of the phosphor layer. The white light forms red light, green light, and blue light under the action of the first color filter. The red light, green light, and blue light colors are mixed to form the required color light.

[0064] In the display device, the light-emitting bodies are controlled by their respective transistors. When the display device is working, the corresponding transistors are controlled by the first to third pads and the first to fourth connecting lines, thereby controlling the turning on or off of the corresponding light-emitting bodies, and realizing active addressing driving of the light-emitting bodies. For example, the external control signal inputs a control voltage to the transistor gate through the second pad 202 and the second connecting line 102, and the position coordinates of each light-emitting body in the display device are set to (X1, Y1), (X2, Y2)...(Xn, Yn), where n is an integer, the first pad 201 includes P1, P2...Pm, which correspond to the first row, the second row...the mth row in the array respectively, and the third pad 203 includes K1, K2...Km, which correspond to the first column, the second column...the mth column in the array respectively, where m is an integer. When P1 and K1 are turned on, the transistors at the position (X1, Y1) in the corresponding first row and first column are controlled to be turned on, and the light-emitting body is lit. For another example, when P1, K1, P2, and K2 are turned on, the transistors at the corresponding positions (X1, Y1) and (X2, Y2) are controlled to be turned on at the same time, and the light-emitting bodies are lit at the same time, thereby realizing the addressing drive of the light-emitting bodies. Similarly, the addressing drive control of single or multiple other light-emitting bodies can be realized.

[0065] It is understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A method for preparing a display device, characterized in that: The method comprises: providing a substrate (1), wherein an epitaxial layer is arranged on the substrate (1), wherein the epitaxial layer comprises at least a non-doped GaN layer (2) and a first-type GaN layer (301) sequentially distributed from bottom to top, wherein the first-type GaN layer (301) comprises N-type GaN; Etching the epitaxial layer to divide the epitaxial layer into a plurality of array distribution areas; Divide each area into a light-emitting area and a driving area; A light-emitting body (3) is prepared in the light-emitting area, a transistor (4) is prepared in the driving area, and the transistor (4) is electrically connected to the corresponding light-emitting body (3) through the first-type GaN layer (301) to control the turning on or off of the light-emitting body (3), thereby obtaining a light-emitting module.

2. The method for preparing a display device according to claim 1, characterized in that: The epitaxial layer further comprises a light-emitting layer (302) and a second-type GaN layer (303); the light-emitting layer (302) is a quantum well layer, and the second-type GaN layer (303) comprises P-type GaN.

3. The method for preparing a display device according to claim 1 or 2, characterized in that: The epitaxial layer is etched using a photolithography and etching process to form a plurality of channels (12), thereby dividing the epitaxial layer into a plurality of array distribution areas.

4. The method for preparing a display device according to claim 1, characterized in that: Preparing a light-emitting body (3) in the light-emitting area and preparing a transistor (4) in the driving area, comprising: using a photolithography and etching process to etch a local area of ​​the epitaxial layer to a depth of a local area of ​​the first-type GaN layer (301), forming a first etching groove (13) and an array of protrusions, wherein the protrusions are the light-emitting body (3); Using a photolithography and etching process, etching the first-type GaN layer (301) at the bottom of the first etching groove (13) to form a second etching groove (14); A patterned source electrode (401) and a patterned drain electrode (402) are prepared on the surface of the first-type GaN layer (301) at the bottom of the first etched groove (13) by using photolithography, deposition and stripping processes; the source electrode (401) and the drain electrode (402) are distributed on both sides of the second etched groove (14) and are electrically connected to the first-type GaN layer (301) below both sides of the second etched groove (14) respectively; Using chemical vapor deposition or atomic layer deposition, the first insulating material is covered on the entire surface of the second etching groove (14) and the surface of the source electrode (401) and the drain electrode (402), thereby forming a first insulating layer (5); A patterned gate (403) is prepared on the upper surface of the first insulating layer (5) by using photolithography, deposition and stripping processes.

5. The method for preparing a display device according to claim 4, characterized in that: A second insulating material is applied to the entire surface including the surface of the gate (403) and the surface of the light-emitting body (3) by chemical vapor deposition or atomic layer deposition, thereby forming a second insulating layer (6).

6. The method for preparing a display device according to claim 5, characterized in that: Using photolithography and etching processes, opening holes in local areas of the second insulating layer (6) and the first insulating layer (5) to expose local areas of the second type GaN layer (303); A P electrode is prepared above the light-emitting body by using photolithography, deposition and stripping processes, and the bottom end of the P electrode (304) sequentially penetrates the second insulating layer (6), the opening in the first insulating layer (5), and is electrically connected to a local area of ​​the second-type GaN layer (303).

7. The method for preparing a display device according to claim 6, characterized in that: A third insulating material is applied to the entire surface including the surface of the P electrode (304) by chemical vapor deposition or atomic layer deposition to form a third insulating layer (7).

8. The method for preparing a display device according to claim 7, characterized in that: A phosphor material is coated on the entire surface including the surface of the third insulating layer (7) to form a phosphor layer (8), wherein the phosphor layer is used to convert the color of light emitted by the light-emitting body (3) into white; and a first color filter (9) is arranged on the surface of the phosphor layer (8), wherein the first color filter (9) corresponds one-to-one to the light-emitting surface of the light-emitting body (3) and is used to convert white into at least three primary colors: red, green and blue.

9. The method for preparing a display device according to claim 7, characterized in that: A second color filter (11) is arranged on the entire surface including the surface of the third insulating layer (7), the second color filter corresponding one-to-one to the light-emitting surface of the light-emitting body (3), and used for converting the color of light emitted by the light-emitting body into at least three primary colors: red, green, and blue.

10. The method for preparing a display device according to claim 8 or 9, characterized in that: A black material is filled in the gap between two adjacent first color filters (9) or between two adjacent second color filters to form a contrast enhancement layer (10).

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