An Inverted Micro LED Full-Color Quantum Dot Chip, Its Preparation Method and Use

Abstract

The present invention relates to an inverted Micro LED full-color quantum dot chip, a preparation method thereof, and uses thereof. The inverted Micro LED full-color quantum dot chip provided by the present invention can form red, blue, and green light-emitting structures on a single LED chip without setting an RGB array, which can greatly improve the mass transfer efficiency and yield; a single chip can not only complete full-color light emission, but also save wafer area and chip cost, which is beneficial to large-scale production by downstream enterprises; the additional quantum materials can prevent the display effect of the chip from being affected by current fluctuations. By providing three negative electrodes and a common positive electrode in the inverted Micro LED full-color quantum dot chip, the present invention can achieve the effects of separate light emission of red, green, and blue, or simultaneous light emission of two light colors, or simultaneous light emission of three light colors on a single chip, realizing adjustable light emission colors.

Description

Technical Field

[0001] The present invention belongs to the technical field of LED chips, and particularly relates to a flip-chip Micro LED full-color quantum dot chip, a preparation method thereof, and uses thereof. Background Art

[0002] LED lamps are widely used lighting fixtures at present, having the advantages of small volume, high brightness, low power consumption, less heat generation, long service life, environmental protection, etc., and having a wide variety of color types, and are deeply loved by consumers.

[0003] The production of LED lamps can be roughly divided into three steps: one is the production of LED light-emitting chips, the second is the production of circuit boards and the encapsulation of LED light-emitting chips, and the third is the assembly of LED lamps. The most important component in an LED lamp is the LED light-emitting chip. The main body of the LED light-emitting chip is a light-emitting PN junction, which is mainly composed of an N-type semiconductor, a P-type semiconductor, and a light-emitting layer sandwiched between the two. Metal electrodes are respectively arranged on the N-type semiconductor and the P-type semiconductor, and light is emitted after being powered on.

[0004] The light color emitted by the LED light-emitting chip is mainly determined by the chip material. For example, most of the existing LED light-emitting chips are made of gallium nitride semiconductor materials and emit blue light. When using a blue LED light-emitting chip to make other monochromatic LED lamps, phosphor needs to be incorporated in the encapsulation step. The light emitted by the phosphor after being excited is mixed with the blue light of the LED light-emitting chip to become light of other colors.

[0005] However, in the prior art, LED chips are generally monochromatic chips, and a single chip cannot obtain a full-color effect, having the following defects: each chip is transferred to a substrate through a die bonding device. In each pixel, three chips need to be transferred, and the production capacity per unit time is limited; three independent RGB LED chips limit the minimum pixel pitch of the display screen; and the processing cost of downstream enterprises is relatively high.

[0006] CN106783830B discloses a red, green, and blue three-color chip LED and a backlight module. The red, green, and blue three-color chip LED includes: a red light chip; a first bracket for fixing the red light chip, and the material of the first bracket has a first thermal resistance value; a green light chip; a second bracket for fixing the green light chip, and the material of the second bracket has a second thermal resistance value; a blue light chip; and a third bracket for fixing the blue light chip, and the material of the third bracket has a third thermal resistance value; wherein, the first thermal resistance value is the smallest, the second thermal resistance value is in the middle, and the third thermal resistance value is the largest. However, a single chip of the LED chip cannot obtain a full-color effect.

[0007] CN107123643A discloses a high color gamut LED lamp bead and its backlight source with a blue-green dual-chip and red phosphor, including a lamp bead body and a backlight source body. The lamp bead body is specifically composed of an LED bracket, a blue light chip, a green light chip, and a red phosphor. The inside of the LED bracket is distributed with the blue light chip and the green light chip. The blue light chip and the green light chip are encapsulated inside the LED bracket after being mixed with the red phosphor and the encapsulation glue and baked and cured. A plurality of the lamp bead bodies are evenly distributed on a side-entry PCB board. However, a single chip of the LED chip cannot obtain a full-color effect.

[0008] CN106449620A discloses a remote quantum dot LED device based on blue and green LED chips, including a carrier and an LED chip disposed on the carrier. The LED chip includes a blue light LED chip and a green light LED chip. A light-transmitting substrate is disposed outside the LED chip, and a layer of red quantum dot glue layer is coated on at least one surface of the light-transmitting substrate. There is air between the red quantum dot glue layer and the LED chip. However, a single chip of the LED chip cannot obtain a full-color effect.

[0009] Therefore, there is a need in the art to develop an LED chip that can obtain a full-color effect with a single chip. Summary of the Invention

[0010] Aiming at the problem in the prior art that a single LED chip cannot obtain a full-color effect, the purpose of the present invention is to provide a flip-chip Micro LED full-color quantum dot chip, its preparation method and uses. A single chip of the flip-chip Micro LED full-color quantum dot chip of the present invention can not only obtain full-color light emission, but also the emission color is controllable.

[0011] To achieve the above object, the present invention adopts the following technical solutions:

[0012] One object of the present invention is to provide a flip-chip Micro LED full-color quantum dot chip. The flip-chip Micro LED full-color quantum dot chip includes a substrate and a first blue light epitaxial layer, a first indium tin oxide layer, a first light-emitting quantum dot layer, a second blue light epitaxial layer, a second indium tin oxide layer, a second light-emitting quantum dot layer, a third blue light epitaxial layer, a third indium tin oxide layer, and a DBR reflection layer sequentially disposed on the surface of the substrate;

[0013] In the flip-chip Micro LED full-color quantum dot chip, the first N electrode penetrates from the chip surface far from the substrate into the first blue light epitaxial layer, the second N electrode penetrates from the chip surface far from the substrate into the second blue light epitaxial layer, the third N electrode penetrates from the chip surface far from the substrate into the third blue light epitaxial layer, and the fourth P electrode penetrates from the chip surface far from the substrate into the first blue light epitaxial layer.

[0014] The flip-chip Micro LED full-color quantum dot chip (MicroLED chip) provided by the present invention can form red, blue, and green light-emitting structures on a single LED chip without setting up an RGB array, which can greatly improve the mass transfer efficiency and yield; a single chip can not only achieve full-color light emission, but also save wafer area and chip cost, which is beneficial to large-scale production by downstream enterprises; the additional quantum materials can make the display effect of the chip not affected by current fluctuations.

[0015] The present invention adds quantum dot light-emitting materials to the stack of blue light chips to generate red, green, and blue light. The structure of the flip-chip Micro LED full-color quantum dot chip of the present invention enables the three-color chips to be combined into one chip, which can reduce the pitch of the display screen and facilitate the batch transfer of the three-color chips using the mass transfer technology; at the same time, by setting three negative electrodes and a common positive electrode in the flip-chip Micro LED full-color quantum dot chip of the present invention, the effects of red, green, and blue single-color light emission, or two-color light emission at the same time, or three-color light emission at the same time can be achieved on one chip, realizing adjustable light emission colors. Among them, if the first light-emitting quantum dot layer is a red light-emitting layer and the second light-emitting quantum dot layer is a green light-emitting layer, the first N electrode is the N pole of red light, the second N electrode is the N pole of green light, the third N electrode is the N pole of blue light, and the fourth P electrode is the common positive electrode. The present invention does not specifically limit the positional relationship between the first N electrode, the second N electrode, the third N electrode, and the fourth P electrode, and those skilled in the art can choose according to actual experience. Exemplarily, the distance between the electrodes is 20-50 μm.

[0016] In the present invention, the DBR reflective layer is hardened, which can prevent the top pin from scratching the bottom of the chip during chip die bonding and can also act as a reflective surface to increase the light extraction efficiency.

[0017] In the present invention, the thicknesses of the respective layers in the flip-chip Micro LED full-color quantum dot chip structure are not specifically limited, and those skilled in the art can select according to actual experience. Exemplarily, for example, the thickness of the first blue light epitaxial layer is 50 - 100 nm, the thickness of the first indium tin oxide layer is 20 - 30 nm, the thickness of the first light-emitting quantum dot layer is 15 - 30 nm, the thickness of the second blue light epitaxial layer is 50 - 100 nm, the thickness of the second indium tin oxide layer is 20 - 30 nm, the thickness of the second light-emitting quantum dot layer is 15 - 30 nm, the thickness of the third blue light epitaxial layer is 50 - 100 nm, the thickness of the third indium tin oxide layer is 20 - 30 nm, and the thickness of the DBR reflective layer is 15 - 20 nm.

[0018] Preferably, the compositions of the first blue light epitaxial layer, the second blue light epitaxial layer, and the third blue light epitaxial layer each independently include: a blue light N-type gallium nitride layer, a blue light active layer, and a blue light P-type gallium nitride layer, which are sequentially disposed on the surface of the substrate.

[0019] In the present invention, the thicknesses of the blue light N-type gallium nitride layer, the blue light active layer, and the blue light P-type gallium nitride layer are not specifically limited, and those skilled in the art can select according to actual experience. Exemplarily, for example, the thickness of the blue light N-type gallium nitride layer is 10 - 20 nm, the thickness of the blue light active layer is 5 - 15 nm, and the thickness of the blue light P-type gallium nitride layer is 10 - 20 nm.

[0020] Preferably, the blue light active layer includes a blue light multi-quantum well material structure.

[0021] Preferably, the first N electrode penetrates from the chip surface away from the substrate to the blue light N-type gallium nitride layer in the first blue light epitaxial layer.

[0022] Preferably, the second N electrode penetrates from the chip surface away from the substrate to the blue light N-type gallium nitride layer in the second blue light epitaxial layer.

[0023] Preferably, the third N electrode penetrates from the chip surface away from the substrate to the blue light N-type gallium nitride layer in the third blue light epitaxial layer.

[0024] Preferably, the fourth P electrode penetrates from the chip surface away from the substrate to the blue light P-type gallium nitride layer in the first blue light epitaxial layer.

[0025] Preferably, between the first light-emitting quantum dot layer and the second blue light epitaxial layer, there is also a first transparent bonding material layer.

[0026] Preferably, between the second light-emitting quantum dot layer and the third blue light epitaxial layer, there is also a second transparent bonding material layer.

[0027] Preferably, the compositions of the first transparent bonding material layer and the second transparent bonding material layer are as follows: a material layer obtained by surface treatment of a silicon oxide layer by introducing gaseous NH 4 OH under the conditions of 100 - 400 °C (such as 150 °C, 200 °C, 250 °C, 300 °C or 350 °C, etc.) and 2.0 - 3.0 Mpa.

[0028] The transparent bonding material layer of the present invention is used for light transmission and connecting the contact surfaces of the upper and lower chips. After the surface treatment of the silicon oxide material, it can be quickly bonded to the contact surface of the chip at high temperature.

[0029] Preferably, the first light - emitting quantum dot layer is a red - light quantum dot layer, and its material composition is a PbS quantum dot material in the red - light band.

[0030] Preferably, the second light - emitting quantum dot layer is a green - light quantum dot layer, and its material composition is a CdSe quantum dot material in the green - light band.

[0031] Preferably, the substrate is a sapphire substrate.

[0032] Preferably, the flip - chip Micro LED full - color quantum dot chip is a miniLED chip.

[0033] The second object of the present invention is to provide a preparation method of the flip - chip Micro LED full - color quantum dot chip as described in the first object, and the method includes the following steps:

[0034] (1) Sequentially prepare a first blue - light epitaxial layer, a first indium tin oxide layer, a first light - emitting quantum dot layer, a second blue - light epitaxial layer, a second indium tin oxide layer, a second light - emitting quantum dot layer, a third blue - light epitaxial layer, a third indium tin oxide layer and a DBR reflective layer on the substrate to obtain an LED wafer;

[0035] (2) Etch the LED wafer, penetrating from the chip surface far from the substrate into the first blue - light epitaxial layer to form a first hole; penetrating from the chip surface far from the substrate into the second blue - light epitaxial layer to form a second hole; penetrating from the chip surface far from the substrate into the third blue - light epitaxial layer to form a third hole; then penetrating from the chip surface far from the substrate into the first blue - light epitaxial layer to form a fourth hole;

[0036] (3) Form a passivation layer on the surface of the LED wafer obtained in step (2), inside the first hole, inside the second hole, inside the third hole and inside the fourth hole; etch the passivation layer, penetrating the passivation layer and correspondingly forming a first negative - electrode hole, a second negative - electrode hole, a third negative - electrode hole and a fourth positive - electrode hole in the first hole, the second hole, the third hole and the fourth hole;

[0037] (4) Deposit a metal layer in the first electrode hole, the second electrode hole, the third electrode hole, and the fourth positive electrode hole in the LED wafer obtained in step (3) to obtain a flip-chip Micro LED full-color quantum dot chip.

[0038] The present invention does not specifically limit the specific preparation processes of the first blue light epitaxial layer, the first indium tin oxide layer, the first light-emitting quantum dot layer, the second blue light epitaxial layer, the second indium tin oxide layer, the second light-emitting quantum dot layer, the third blue light epitaxial layer, the third indium tin oxide layer, and the DBR reflective layer. Those skilled in the art can select according to actual needs.

[0039] Preferably, between the first light-emitting quantum dot layer and the second blue light epitaxial layer in step (1), there is also a process of preparing a first transparent bonding material layer.

[0040] Preferably, between the second light-emitting quantum dot layer and the third blue light epitaxial layer in step (1), there is also a process of preparing a second transparent bonding material layer.

[0041] The present invention does not specifically limit the specific preparation processes of the first transparent bonding material layer and the second transparent bonding material layer. Those skilled in the art can select according to actual needs.

[0042] As a preferred technical solution, the preparation method of a flip-chip Micro LED full-color quantum dot chip according to the present invention includes the following steps:

[0043] (1) Prepare a first blue light epitaxial layer on a substrate. The preparation process of the first blue light epitaxial layer is as follows: prepare a blue light N-type gallium nitride layer on the substrate, prepare a blue light active layer on the surface of the blue light N-type gallium nitride layer, and prepare a blue light P-type gallium nitride layer on the surface of the blue light active layer; then sequentially prepare a first indium tin oxide layer and a red light quantum dot layer on the first blue light epitaxial layer;

[0044] (2) Sequentially prepare a first transparent bonding material layer and a second blue light epitaxial layer on the red light quantum dot layer. The preparation process of the second blue light epitaxial layer is as follows: prepare a blue light N-type gallium nitride layer on the red light quantum dot layer, prepare a blue light active layer on the surface of the blue light N-type gallium nitride layer, and prepare a blue light P-type gallium nitride layer on the surface of the blue light active layer; then sequentially prepare a second indium tin oxide layer and a green light quantum dot layer on the second blue light epitaxial layer;

[0045] (3) A second transparent bonding material layer and a third blue light epitaxial layer are sequentially prepared on the green light quantum dot layer. The preparation process of the third blue light epitaxial layer is as follows: a blue light N-type gallium nitride layer is prepared on the green light quantum dot layer, a blue light active layer is prepared on the surface of the blue light N-type gallium nitride layer, and a blue light P-type gallium nitride layer is prepared on the surface of the blue light active layer; then a third indium tin oxide layer and a DBR reflective layer are sequentially prepared on the third blue light epitaxial layer to obtain an LED wafer;

[0046] (4) The LED wafer is etched, penetrating from the chip surface far from the substrate to the blue light N-type gallium nitride layer in the first blue light epitaxial layer to form a first hole; penetrating from the chip surface far from the substrate to the blue light N-type gallium nitride layer in the second blue light epitaxial layer to form a second hole; penetrating from the chip surface far from the substrate to the blue light N-type gallium nitride layer in the third blue light epitaxial layer to form a third hole; then penetrating from the chip surface far from the substrate to the blue light P-type gallium nitride layer in the first blue light epitaxial layer to form a fourth hole;

[0047] (5) A passivation layer is formed on the surface of the LED wafer obtained in step (4), inside the first hole, inside the second hole, inside the third hole, and inside the fourth hole; the passivation layer is etched, penetrating the passivation layer and correspondingly forming a first negative electrode hole, a second negative electrode hole, a third negative electrode hole, and a fourth positive electrode hole in the first hole, the second hole, the third hole, and the fourth hole;

[0048] (6) In the LED wafer obtained in step (5), a metal layer is deposited in the first electrode hole, the second electrode hole, the third electrode hole, and the fourth positive electrode hole to obtain a flip-chip Micro LED full-color quantum dot chip.

[0049] A third object of the present invention is to provide a use of the flip-chip Micro LED full-color quantum dot chip as described in the first object, and the flip-chip Micro LED full-color quantum dot chip is used for the preparation of an ultra-high definition display screen and / or a microLED display screen.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] (1) The flip-chip Micro LED full-color quantum dot chip (MicroLED chip) provided by the present invention can form a red, blue, and green light-emitting structure on a single LED chip, without the need to set up an RGB array, which can greatly improve the mass transfer efficiency and yield; a single chip can not only complete full-color light emission, but also save wafer area and chip cost, which is beneficial to large-scale production by downstream enterprises; the additional quantum material can make the display effect of the chip not affected by current fluctuations.

[0052] (2) By providing three negative electrodes and one common positive electrode in the flip-chip Micro LED full-color quantum dot chip of the present invention, the effects of separately emitting red, green, and blue light colors, or simultaneously emitting two light colors, or simultaneously emitting three light colors can be achieved on a single chip, realizing adjustable emission light colors. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 is a front view of the flip-chip Micro LED full-color quantum dot chip structure provided in Embodiment 1 of the present invention;

[0054] Figure 2 is a left view of the flip-chip Micro LED full-color quantum dot chip structure provided in Embodiment 1 of the present invention;

[0055] Figure 3 is a top view of the flip-chip Micro LED full-color quantum dot chip structure provided in Embodiment 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0056] To facilitate the understanding of the present invention, the following embodiments are enumerated. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations to the present invention.

[0057] Embodiment 1

[0058] In this embodiment, the front view of the flip-chip Micro LED full-color quantum dot chip structure is as shown in Figure 1 , the left view is as shown in Figure 2 , and the top view is as shown in Figure 3 . It includes a substrate 1, a first blue light epitaxial layer 2, a first indium tin oxide layer 3, a first light-emitting quantum dot layer 4, a first transparent bonding material layer 5, a second blue light epitaxial layer 6, a second indium tin oxide layer 7, a second light-emitting quantum dot layer 8, a second transparent bonding material layer 9, a third blue light epitaxial layer 10, a third indium tin oxide layer 11, a DBR reflection layer 12, a fourth P electrode 13, a first N electrode 14, a second N electrode 15, and a third N electrode 16.

[0059] In this embodiment, the substrate 1 is a sapphire substrate with a thickness of 100 μm; the first blue light epitaxial layer 2 includes a blue light N-type gallium nitride layer with a thickness of 20 nm disposed on the surface of the substrate 1, a blue light active layer with a thickness of 10 nm, and a blue light P-type gallium nitride layer with a thickness of 10 nm. The material of the blue light active layer is a blue light multi-quantum well; the thicknesses of the first indium tin oxide layer 3, the second indium tin oxide layer 7, and the third indium tin oxide layer 11 are 20 nm; the thickness of the first light-emitting quantum dot layer 4 is 15 nm, and the material is a PbS quantum dot material in the red light band; the thickness of the second light-emitting quantum dot layer 8 is 15 nm, and the material is a CdSe quantum dot material in the green light band; the thicknesses of the first transparent bonding material layer 5 and the second transparent bonding material layer 9 are 5 nm, and the material is a surface-treated silicon oxide layer (under the conditions of 300 °C and 2.5 Mpa, gaseous NH 4 OH is introduced for surface treatment); the thickness of the DBR reflection layer 12 is 20 nm; the thicknesses and material compositions of the second blue light epitaxial layer 6 and the third blue light epitaxial layer 10 are the same as those of the first blue light epitaxial layer 2.

[0060] In this embodiment, the first N electrode 14 penetrates from the chip surface far from the substrate to the blue light N-type gallium nitride layer in the first blue light epitaxial layer to obtain a red light N pole; the second N electrode 15 penetrates from the chip surface far from the substrate to the blue light N-type gallium nitride layer in the second blue light epitaxial layer to obtain a green light N pole; the third N electrode 16 penetrates from the chip surface far from the substrate to the blue light N-type gallium nitride layer in the third blue light epitaxial layer to obtain a blue light N pole; the fourth P electrode 13 penetrates from the chip surface far from the substrate to the blue light P-type gallium nitride layer in the first blue light epitaxial layer to obtain a common positive electrode.

[0061] Comparative Example 1

[0062] The difference from Example 1 is that the DBR reflection layer 12 is not provided.

[0063] In Comparative Example 1, without the DBR reflection layer 12, the chip obtained has a worse effect than the chip in Example 1.

[0064] The applicant declares that the present invention uses the above embodiments to illustrate the detailed process equipment and process flow of the present invention, but the present invention is not limited to the above detailed process equipment and process flow, that is, it does not mean that the present invention must rely on the above detailed process equipment and process flow to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent replacement of each raw material of the present invention's product, the addition of auxiliary components, and the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A flip-chip Micro LED full-color quantum dot chip, characterized in that, the flip-chip Micro LED full-color quantum dot chip includes a substrate and a first blue light epitaxial layer, a first indium tin oxide layer, a first light-emitting quantum dot layer, a second blue light epitaxial layer, a second indium tin oxide layer, a second light-emitting quantum dot layer, a third blue light epitaxial layer, a third indium tin oxide layer, and a DBR reflective layer that are sequentially arranged on the surface of the substrate; the compositions of the first blue light epitaxial layer, the second blue light epitaxial layer, and the third blue light epitaxial layer each independently include: a blue light N-type gallium nitride layer, a blue light active layer, and a blue light P-type gallium nitride layer that are sequentially arranged on the surface of the substrate; in the flip-chip Micro LED full-color quantum dot chip, a first N electrode penetrates from the chip surface far from the substrate to the blue light N-type gallium nitride layer in the first blue light epitaxial layer, a second N electrode penetrates from the chip surface far from the substrate to the blue light N-type gallium nitride layer in the second blue light epitaxial layer, a third N electrode penetrates from the chip surface far from the substrate to the blue light N-type gallium nitride layer in the third blue light epitaxial layer, and a fourth P electrode penetrates from the chip surface far from the substrate to the blue light P-type gallium nitride layer in the first blue light epitaxial layer.

2. The flip-chip Micro LED full-color quantum dot chip according to claim 1, characterized in that, the blue light active layer includes a blue light multi-quantum well material structure.

3. The flip-chip Micro LED full-color quantum dot chip according to claim 1, characterized in that, a first transparent bonding material layer is further included between the first light-emitting quantum dot layer and the second blue light epitaxial layer.

4. The flip-chip Micro LED full-color quantum dot chip according to claim 1, characterized in that, a second transparent bonding material layer is further included between the second light-emitting quantum dot layer and the third blue light epitaxial layer.

5. The flip-chip Micro LED full-color quantum dot chip according to claim 3 or 4, characterized in that, The compositions of the first transparent bonding material layer and the second transparent bonding material layer are material layers obtained by surface treatment of a silicon oxide layer by introducing gaseous NH 4 OH under the conditions of 100 to 400 °C and 2.0 to 3.0 Mpa.

6. The flip-chip Micro LED full-color quantum dot chip according to claim 1, characterized in that, the first light-emitting quantum dot layer is a red light quantum dot layer, and its material composition is a PbS quantum dot material in the red light band.

7. The flip-chip Micro LED full-color quantum dot chip according to claim 1, characterized in that, the second light-emitting quantum dot layer is a green light quantum dot layer, and its material composition is a CdSe quantum dot material in the green light band.

8. The flip-chip Micro LED full-color quantum dot chip according to claim 1, characterized in that, the substrate is a sapphire substrate.

9. The flip-chip Micro LED full-color quantum dot chip according to claim 1, characterized in that, the flip-chip Micro LED full-color quantum dot chip is a miniLED chip.

10. A preparation method of the flip-chip Micro LED full-color quantum dot chip according to any one of claims 1-9, characterized in that, the method includes the following steps: (1) A first blue light epitaxial layer, a first indium tin oxide layer, a first light-emitting quantum dot layer, a second blue light epitaxial layer, a second indium tin oxide layer, a second light-emitting quantum dot layer, a third blue light epitaxial layer, a third indium tin oxide layer, and a DBR reflective layer are sequentially prepared on a substrate to obtain an LED wafer; (2) The LED wafer is etched, penetrating from the chip surface away from the substrate into the first blue light epitaxial layer to form a first hole; penetrating from the chip surface away from the substrate into the second blue light epitaxial layer to form a second hole; penetrating from the chip surface away from the substrate into the third blue light epitaxial layer to form a third hole; and then penetrating from the chip surface away from the substrate into the first blue light epitaxial layer to form a fourth hole; (3) A passivation layer is formed on the surface of the LED wafer obtained in step (2), inside the first hole, inside the second hole, inside the third hole, and inside the fourth hole; The passivation layer is etched, penetrating through the passivation layer and correspondingly forming a first negative electrode hole, a second negative electrode hole, a third negative electrode hole, and a fourth positive electrode hole in the first hole, the second hole, the third hole, and the fourth hole; (4) In the LED wafer obtained in step (3), a metal layer is deposited in the first electrode hole, the second electrode hole, the third electrode hole, and the fourth positive electrode hole to obtain a flip-chip Micro LED full-color quantum dot chip.

11. The method according to claim 10, characterized in that, between the first light-emitting quantum dot layer and the second blue light epitaxial layer in step (1), a process of preparing a first transparent bonding material layer is further included.

12. The method according to claim 10, characterized in that, between the second light-emitting quantum dot layer and the third blue light epitaxial layer in step (1), a process of preparing a second transparent bonding material layer is further included.

13. The method according to claim 10, characterized in that, the method includes the following steps: (1) A first blue light epitaxial layer is prepared on a substrate, and the preparation process of the first blue light epitaxial layer is: preparing a blue light N-type gallium nitride layer on the substrate, preparing a blue light active layer on the surface of the blue light N-type gallium nitride layer, and preparing a blue light P-type gallium nitride layer on the surface of the blue light active layer; then a first indium tin oxide layer and a red light quantum dot layer are sequentially prepared on the first blue light epitaxial layer; (2) A first transparent bonding material layer and a second blue light epitaxial layer are sequentially prepared on the red light quantum dot layer, and the preparation process of the second blue light epitaxial layer is: preparing a blue light N-type gallium nitride layer on the red light quantum dot layer, preparing a blue light active layer on the surface of the blue light N-type gallium nitride layer, and preparing a blue light P-type gallium nitride layer on the surface of the blue light active layer; then a second indium tin oxide layer and a green light quantum dot layer are sequentially prepared on the second blue light epitaxial layer; (3) A second transparent bonding material layer and a third blue light epitaxial layer are sequentially prepared on the green light quantum dot layer. The preparation process of the third blue light epitaxial layer is as follows: a blue light N-type gallium nitride layer is prepared on the green light quantum dot layer, a blue light active layer is prepared on the surface of the blue light N-type gallium nitride layer, and a blue light P-type gallium nitride layer is prepared on the surface of the blue light active layer; then a third indium tin oxide layer and a DBR reflection layer are sequentially prepared on the third blue light epitaxial layer to obtain an LED wafer; (4) The LED wafer is etched, penetrating from the chip surface far from the substrate to the blue light N-type gallium nitride layer in the first blue light epitaxial layer to form a first hole; penetrating from the chip surface far from the substrate to the blue light N-type gallium nitride layer in the second blue light epitaxial layer to form a second hole; penetrating from the chip surface far from the substrate to the blue light N-type gallium nitride layer in the third blue light epitaxial layer to form a third hole; then penetrating from the chip surface far from the substrate to the blue light P-type gallium nitride layer in the first blue light epitaxial layer to form a fourth hole; (5) A passivation layer is formed on the surface of the LED wafer obtained in step (4), inside the first hole, inside the second hole, inside the third hole, and inside the fourth hole; The passivation layer is etched, penetrating the passivation layer and correspondingly forming a first negative electrode hole, a second negative electrode hole, a third negative electrode hole, and a fourth positive electrode hole in the first hole, the second hole, the third hole, and the fourth hole; (6) In the LED wafer obtained in step (5), a metal layer is deposited in the first electrode hole, the second electrode hole, the third electrode hole, and the fourth positive electrode hole to obtain a flip-chip Micro LED full-color quantum dot chip.

14. Use of a flip-chip Micro LED full-color quantum dot chip according to any one of claims 1-9, characterized in that, the flip-chip Micro LED full-color quantum dot chip is used for the preparation of an ultra-high definition display screen and / or a Micro LED display screen.

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