CN115810699A

CN115810699A - Micro-LED display panel and preparation method thereof

Info

Publication number: CN115810699A
Application number: CN202211656501.6A
Authority: CN
Inventors: 徐涛; 饶巍巍; 姜发明; 徐贤强
Original assignee: Shenzhen Australis Electronic Technology Co Ltd
Current assignee: Shenzhen Australis Electronic Technology Co Ltd
Priority date: 2022-12-22
Filing date: 2022-12-22
Publication date: 2023-03-17

Abstract

The application relates to a Micro-LED display panel and a preparation method thereof, wherein an insulating heat conductor is filled in a first through hole of a substrate, a bonding pad is arranged on the substrate, and a first insulating heat conduction layer covers the substrate, so that one side of the bonding pad, which is far away from the substrate, is exposed; the electrode is stacked on the first insulating heat conduction layer and the bonding pad, a second through hole opposite to the first insulating heat conduction layer is arranged in the electrode in a penetrating mode, and a heat conductor is filled in the second through hole; the electrodes are provided with a plurality of spaced light emitting layers, a second insulating heat conduction layer is filled between every two adjacent light emitting layers and is opposite to the second through hole, and the side faces, facing the light emitting layers, of the second insulating heat conduction layers are not light-transmitting; the second insulating heat-conducting layer between the blue LED pixel unit and the red LED pixel unit/the green LED pixel unit is in a right trapezoid shape in longitudinal section, and the second insulating heat-conducting layer between the green LED pixel unit and the red LED pixel unit is in a rectangular shape in longitudinal section. This application has the effect that improves the heat dispersion of chip.

Description

Micro-LED display panel and preparation method thereof

Technical Field

The application relates to the technical field of display devices, in particular to a Micro-LED display panel and a preparation method thereof.

Background

The Micro-LED display technology is a display technology which takes self-luminous micrometer-scale LEDs as light-emitting pixel units and assembles the light-emitting pixel units on a driving panel to form a high-density LED array. Due to the characteristics of small size, high integration level, self-luminescence and the like of the micro-LED chip, compared with an LCD and an OLED, the micro-LED chip has the advantages of higher brightness, resolution, contrast, energy consumption, service life, response speed, thermal stability and the like in the aspect of display.

The display principle of the Micro-LED is that after the traditional LED chip structure design is thinned, miniaturized and arrayed, the size of the formed Micro-LED chip is only in the grade of 1 to 10 mu m; then transferring the micro-LED chips to a substrate with a driving circuit, which is manufactured by adopting PCB, flexible PCB, CMOS/TFT integrated circuit technology and the like, in a batch mode, then completing the preparation of a protective layer and an upper electrode by utilizing physical vapor deposition and/or chemical vapor deposition technology, and finally packaging the upper substrate to obtain the micro-LED display.

The existing Micro-LED display has a large number of Micro-LED chips, so that the heat dissipation performance is poor, the LED attenuation is faster possibly caused by a long-term high-temperature environment, and the service life of a Micro-LED display screen is shortened; LED lamp heat dissipation is inhomogeneous, and red, green, blue three kinds of LED lamp decay rate are inhomogeneous, are more likely to lead to screen color deviation, and long-term use can lead to the flower screen.

Disclosure of Invention

In order to improve the heat dissipation performance of a chip, the application provides a Micro-LED display panel and a preparation method thereof.

The Micro-LED display panel and the preparation method thereof adopt the following technical scheme:

in a first aspect, the present application provides a Micro-LED display panel, comprising:

the substrate comprises a plurality of spaced mounting areas, a non-mounting area is arranged between every two adjacent mounting areas, first through holes penetrate through the non-mounting areas of the substrate, and insulating heat conductors are filled in the first through holes;

each mounting area of the substrate is provided with a bonding pad, a first insulating heat conduction layer covers the substrate, and the bonding pads are wrapped by the first insulating heat conduction layer so that one side of each bonding pad, which is far away from the substrate, is exposed; and the number of the first and second groups,

the electrode is laminated on the first insulating heat conduction layer and the bonding pad, a second through hole opposite to the first insulating heat conduction layer is arranged in the electrode in a penetrating mode, and a heat conductor is filled in the second through hole;

a plurality of spaced light emitting layers are arranged on the electrodes, a second insulating heat conduction layer is filled between every two adjacent light emitting layers, the second insulating heat conduction layer is opposite to the second through hole, and the side face, facing the light emitting layers, of the second insulating heat conduction layer is not light-transmitting;

each light emitting layer corresponds to a red LED pixel unit or a green LED pixel unit or a blue LED pixel unit, the second insulating and heat conducting layer between the blue LED pixel unit and the red LED pixel unit is in a right trapezoid shape in a longitudinal section, the second insulating and heat conducting layer between the blue LED pixel unit and the green LED pixel unit is in a right trapezoid shape in a longitudinal section, and the inclined edges of the second insulating and heat conducting layers in the right trapezoid shape face the blue LED pixel unit; the second insulating and heat conducting layer between the green LED pixel units and the red LED pixel units is rectangular in longitudinal section.

Through adopting above-mentioned technical scheme, the electrode is range upon range of on first insulation heat-conducting layer and pad, realizes the electric conduction between a plurality of chips, is favorable to the diffusion of electric current, can improve the conduction efficiency of electric current, and the cross section increase of electrode can reduce the resistance on electric current conduction layer simultaneously, promotes display panel's luminance homogeneity. The whole electrode is laid on the first insulating heat conduction layer, so that the stability of the electrode mounted on the substrate can be enhanced.

The electrode is electrically connected with the pad on the one hand, and on the other hand, the electrode is thermally conducted with the first insulating heat conduction layer, the heat in the circumferential direction of the luminous layer can be transmitted to the second heat conduction insulating layer, the heat at the bottom of the luminous layer can be transmitted to the electrode and the insulator in the second through hole, and then the heat is dissipated through the first insulating heat conduction layer and the heat conductor in the first through hole, so that the Micro-LED is convenient to dissipate heat quickly, the heat dissipation performance of the Micro-LED can be effectively improved, the service life of the Micro-LED display panel can be prolonged, and the possibility of occurrence of a flower screen is reduced.

Through setting up the second heat-insulating layer between blue LED pixel unit and red LED pixel unit/green LED pixel unit to right trapezoid on longitudinal section, set up the second heat-insulating layer between green LED pixel unit and the red LED pixel unit to the rectangle on longitudinal section, realize the wide visual angle outgoing of blue light, improve the luminance of blue light, reduce the luminance of ruddiness and green glow, thereby reduce the difference between blue light luminance and red green light luminance, improve the red blue green three-color light and carry out the equilibrium of colour mixture.

Optionally, the electrode is a conductive reflective layer.

By adopting the technical scheme, the electrode not only has the function of conducting electricity, but also has the function of reflecting light, so that light rays emitted by the luminous layer are reflected by the electrode and emitted from one side of the second semiconductor layer, and the light extraction efficiency is improved.

Optionally, a light absorbing layer is disposed on one side of the second insulating and heat conducting layer facing the green LED pixel unit.

Through adopting above-mentioned technical scheme, the light that the luminescent layer of green LED pixel unit sent is shone on the light-absorbing layer, is absorbed by the light-absorbing layer, blocks that the light that the luminescent layer of green LED pixel unit sent jets out to adjacent LED chip to improve the light extraction efficiency of LED chip, reduced the light crosstalk between the pixel.

Optionally, a light absorbing layer is disposed on one side of the second insulating and heat conducting layer facing the red LED pixel unit.

By adopting the technical scheme, light emitted by the light emitting layer of the red LED pixel unit irradiates the light absorbing layer and is absorbed by the light absorbing layer, and the light emitted by the light emitting layer of the red LED pixel unit is prevented from being emitted to the adjacent LED chip, so that the light extraction efficiency of the LED chip is improved, and the light crosstalk between pixels is reduced.

Optionally, a reflective layer is disposed on a side of the second insulating and heat conducting layer facing the blue LED pixel unit.

By adopting the technical scheme, light emitted by the light emitting layer of the blue LED pixel unit irradiates the Bragg reflecting layer, the Bragg reflecting layer generates periodic reflection, and the blue light extraction efficiency of the LED chip is improved.

Optionally, the sizes of the second insulating heat conduction layers in the right trapezoid are the same, the sizes of the second insulating heat conduction layers in the rectangular shape are the same, and one half of the sum of the upper bottom and the lower bottom of the second insulating heat conduction layer in the right trapezoid is the same as the width of the second insulating heat conduction layer in the rectangular shape.

By adopting the technical scheme, the conduction quantity of each second insulating heat conduction layer is the same, so that the heat dissipation efficiency of each pixel is balanced.

Optionally, one end of the pad, which is away from the substrate, protrudes out of the first insulating heat conduction layer, a groove matched with the pad is formed in one side, facing the first insulating heat conduction layer, of the electrode, and the end, protruding out of the pad, of the first insulating heat conduction layer is located in the groove.

By adopting the technical scheme, the electrode is convenient to be positioned on the substrate, and meanwhile, the electric connection between the bonding pad and the electrode is facilitated.

Optionally, the pad has a resistivity less than a resistivity of the electrode.

By adopting the technical scheme, the pad with smaller resistivity is inserted into the groove of the electrode, so that the resistance of the current conducting layer can be further reduced, and the brightness uniformity of the display panel is improved.

In a second aspect, the present application provides a method for manufacturing a Micro-LED display panel, including the following steps:

s1, providing a growth substrate, growing an epitaxial layer on the growth substrate, and etching the epitaxial layer to form a plurality of spaced boss-shaped light emitting layers and a plurality of spaced columnar light emitting layers, wherein the boss-shaped light emitting layers correspond to blue LED pixel units, and the columnar light emitting layers correspond to red LED pixel units or green LED pixel units; filling liquid curable insulating heat conduction materials between the adjacent light emitting layers until the liquid curable insulating heat conduction materials are flush with the light emitting layers, preparing a whole layer of electrodes on the light emitting layers and the insulating heat conduction materials after the insulating heat conduction materials are cured, forming second through holes opposite to the insulating heat conduction materials by opening holes in the electrodes, and filling heat conduction materials in the second through holes;

s2, providing a substrate, forming a first through hole in the substrate, filling liquid curable insulating heat conduction materials on the substrate and in the first through hole to expose a pad on the substrate, and waiting for the insulating heat conduction materials to be cured;

s3, the luminous layer is installed on the substrate through flip-chip welding, the electrode is electrically connected with the bonding pad, the insulating heat conduction material on the substrate is attached to the electrode, and the growth substrate is peeled off.

Through adopting above-mentioned technical scheme, pass through the flip-chip bonding with the luminescent layer on the base plate, can realize the whole face setting of electrode, be favorable to the diffusion of electric current, promote display panel's luminance homogeneity. The light-emitting layer is prepared firstly, and then the second insulating heat-conducting layer between the light-emitting layers is prepared, so that the second insulating heat-conducting layer around the blue light-emitting layer is in a right-angled trapezoid shape on the section, the difference between the blue light brightness and the red and green light brightness can be reduced, and the balance of color mixing of red, blue, green and three colors of light is improved.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the electrode is arranged on the whole surface, so that current diffusion is facilitated, the current conduction efficiency can be improved, the resistance of the current conduction layer is reduced, and the brightness uniformity of the display panel is improved. The whole electrode is laid on the first insulating heat conduction layer, so that the stability of the electrode mounted on the substrate can be enhanced.

2. The second insulating heat conduction layer is distributed around the light emitting layer, and the first insulating heat conduction layer is arranged below the whole-surface electrode, so that the Micro-LED can be quickly cooled, the heat dissipation performance of the Micro-LED can be effectively improved, the service life of the Micro-LED display panel can be prolonged, and the possibility of occurrence of a patterned screen is reduced.

3. Through setting up the second insulation heat-conducting layer to right trapezoid and rectangle on longitudinal section, realize the wide visual angle outgoing of blue light, improve the luminance of blue light, reduce ruddiness and green glow's luminance to reduce the difference between blue light luminance and red green luminance, improve red blue green three-color light and carry out the equilibrium of colour mixture.

4. The pad sets up in the recess of first insulation heat-conducting layer, is convenient for be connected between electrode and the base plate, and the resistivity of pad is less than the resistivity of electrode, can promote display panel's luminance homogeneity.

Drawings

FIG. 1 is a schematic structural view of a first cross section of a Micro-LED display panel in embodiment 1 of the present application;

FIG. 2 is a schematic structural view of a second cross section of a Micro-LED display panel in embodiment 1 of the present application;

FIG. 3 is a schematic structural diagram of a first cross section of a Micro-LED display panel in embodiment 2 of the present application;

fig. 4 to 8 are schematic flow charts of a Micro-LED display panel manufacturing method in embodiment 3 of the present application.

Description of reference numerals: 1. a substrate; 11. a first through hole; 2. an insulating heat conductor; 3. a pad; 4. a first insulating heat conducting layer; 5. an electrode; 51. a second through hole; 52. a groove; 6. a heat conductor; 7. a light emitting layer; 8. a second insulating heat conducting layer; 9. a light absorbing layer; 10. a reflective layer; 100. growing a substrate; 200. an epitaxial layer; 201. a second semiconductor layer; 202. a quantum hydrazine layer; 203. a first semiconductor layer; 300. a blue LED pixel unit; 400. a red LED pixel unit; 500. and a green LED pixel unit.

Detailed Description

The present application is described in further detail below with reference to figures 1-8.

Example 1

The embodiment of the application discloses a Micro-LED display panel. Referring to fig. 1, the micro-LED display panel includes a substrate 1 and a plurality of LED chips, each LED chip includes an electrode 5 and a light emitting layer 7, and the substrate 1 is used for carrying the LED chip and controlling the LED chip to emit light. The substrate 1 may be a driving backplane including a driving circuit for driving the light emitting layer 7 of the LED chip to emit light, which may be a CMOS driving circuit.

The substrate 1 comprises a plurality of spaced mounting areas, each mounting area is used for mounting an LED chip, a non-mounting area is arranged between every two adjacent mounting areas, each mounting area of the substrate 1 is provided with a bonding pad 3, and the bonding pads 3 are used for being welded with electrodes 5 of the LED chips so as to realize the electrical connection of the substrate 1 and the LED chips.

The non-mounting area of base plate 1 all runs through and is equipped with first through-hole 11, and first through-hole 11 intussuseption is filled with insulating heat conductor 2, and the material of insulating heat conductor 2 can be silica gel, heat conduction resin etc..

The base plate 1 coats and is stamped first insulation heat-conducting layer 4, and first insulation heat-conducting layer 4 wraps up pad 3 to make one side that pad 3 deviates from base plate 1 expose, first insulation heat-conducting layer 4 realizes the heat with the insulating heat conductor 2 in the first through-hole 11 and switches on, and the material of first insulation heat-conducting layer 4 can be silica gel, heat conduction resin etc..

The electrodes 5 of the plurality of LED chips are integrally formed and stacked on the first heat-insulating layer 4 and the bonding pads 3 over the entire surface, and the electrodes 5 are electrically connected to the bonding pads 3 and thermally connected to the first heat-insulating layer 4. The electrode 5 is provided with a second through hole 51 opposite to the first insulating and heat conducting layer 4 in a penetrating manner, the second through hole 51 is filled with a heat conductor 6, the heat conductor 6 can be insulating or conductive, and the heat conductor 6 in the second through hole 51 is in thermal conduction with the first insulating and heat conducting layer 4.

In an embodiment, an ohmic contact layer may be disposed between the electrode 5 and the light emitting layer 7, and the ohmic contact layer is configured to enable holes generated in the p-type semiconductor layer and/or electrons generated in the n-type semiconductor layer to be effectively injected into the quantum hydrazine layer 202, and in the quantum hydrazine layer 202, the electrons and the holes are recombined to emit photons, thereby completing conversion from electrical energy to optical energy, and realizing light emission of the first color pixel 111, so as to increase the light emitting efficiency of the Micro-LED display panel.

The light emitting layers 7 of the LED chips are spaced and disposed on the electrode 5, each light emitting layer 7 includes a first semiconductor layer 203, a quantum hydrazine layer 202, and a second semiconductor layer 201 (fig. 5 to 7 can be combined), which are stacked, a second insulating and heat conducting layer 8 is filled between two adjacent light emitting layers 7, the second insulating and heat conducting layer 8 is opposite to the second through hole 51, the second insulating and heat conducting layer 8 is thermally conducted with the heat conductor 6 in the second through hole 51, and the second insulating and heat conducting layer 8 may be made of silica gel, heat conducting resin, or the like.

Each light-emitting layer 7 corresponds to a red LED pixel unit 400 or a green LED pixel unit 500 or a blue LED pixel unit 300. In an alternative embodiment, the light emitting layer 7 corresponding to the red LED pixel unit 400 may emit red light, the light emitting layer 7 corresponding to the blue LED pixel unit 300 may emit blue light, the light emitting layer 7 corresponding to the green LED pixel unit 500 may emit green light, and the side of the second insulating and heat conducting layer 8 facing the light emitting layer 7 is not transparent. In another alternative embodiment, the light emitting layers 7 corresponding to the pixel units have the same structure and can emit blue light, and color conversion can be achieved by providing the red LED pixel unit 400 with a red quantum dot conversion layer corresponding to the light emitting layer 7 and providing the green LED pixel unit 500 with a green quantum dot conversion layer corresponding to the light emitting layer 7.

The second insulating and heat conducting layer 8 between the blue LED pixel unit 300 and the red LED pixel unit 400 is a right trapezoid in longitudinal section, the second insulating and heat conducting layer 8 between the blue LED pixel unit 300 and the green LED pixel unit 500 is a right trapezoid in longitudinal section, and the oblique sides of the second insulating and heat conducting layer 8 in a right trapezoid face the blue LED pixel unit 300. Referring to fig. 2, the second insulating and heat conducting layer 8 between the green LED pixel cell 500 and the red LED pixel cell 400 is rectangular in longitudinal section.

It can be understood that one side of each light-emitting layer 7 opposite to the electrode 5 needs to be electrically connected to a conductive layer, and in order to avoid affecting the light-emitting efficiency of the light-emitting layer 7, the conductive layer may be disposed on the second insulating and heat-conducting layer 8, or the material of the conductive layer may be a light-transmitting material, for example, indium tin oxide, indium zinc oxide, indium gallium oxide, zinc aluminum oxide, or other light-transmitting materials.

This application sets up the electrode 5 of a plurality of LED chips to integrated into one piece and whole face lays on first insulation heat-conducting layer 4, can guarantee the stationarity of LED chip, and whole face electrode 5 is favorable to the diffusion of electric current simultaneously, can improve the conduction efficiency of electric current. The whole electrode 5 is used as a current conducting layer for communicating the light-emitting layer 7 and the substrate 1, so that the resistance of the current conducting layer can be reduced, and the brightness uniformity of the display panel can be improved.

The periphery of each luminous layer 7 is coated by the second insulating heat-conducting layer 8, the heat of the LED chip can be transferred to the first insulating heat-conducting layer 4 through the second insulating heat-conducting layer 8, the heat conductor 6 of the second through hole 51 and the electrode 5, and then the heat is dissipated through the insulating heat conductor 2 in the first through hole 11, so that the Micro-LED can dissipate heat quickly, the heat dissipation performance of the Micro-LED can be effectively improved, the service life of the Micro-LED display panel can be prolonged, and the possibility of the occurrence of the screen is reduced.

Because the wavelength of the blue light is minimum, the problem of insufficient blue light exists in the red, blue and green light, on one hand, the pixel area of the blue light is larger than that of the red light and that of the green light through the second insulating heat-conducting layer 8 with the right trapezoid, so that the blue light is emitted at a wide viewing angle, and the brightness of the blue light is improved; on the other hand, partial light emitted by the red light LED and partial light emitted by the green light LED are shielded by the right-angle sides of the second insulating heat conduction layers 8 in the shape of a right trapezoid, and partial light is emitted from the middle of the two adjacent second insulating heat conduction layers 8, so that the brightness of red light and green light is reduced, the difference between the brightness of blue light and the brightness of red light and green light is reduced, and the balance of color mixing of red light, blue light and green light is improved.

In an optional embodiment, the electrode 5 is a conductive reflective layer, the electrode 5 may be Ag, al, or the like, in a specific embodiment, the electrode 5 is a mirror silver, and the electrode 5 not only plays a role of conducting but also plays a role of reflecting light, so that light emitted from the light emitting layer 7 is reflected by the electrode 5 and emitted from one side of the second semiconductor layer 201, thereby improving light extraction efficiency.

In an optional embodiment, a reflective layer 10 is disposed on a side of the second insulating and heat conducting layer 8 facing the blue LED pixel unit 300, the reflective layer 10 is a bragg reflective layer, light emitted from the light emitting layer 7 of the blue LED pixel unit 300 irradiates the bragg reflective layer, the bragg reflective layer will generate periodic reflection, and the blue light extraction efficiency of the LED chip is improved.

One side of the second insulating and heat conducting layer 8 facing the green LED pixel unit 500 is provided with a light absorbing layer 9, one side of the second insulating and heat conducting layer 8 facing the red LED pixel unit 400 is provided with a light absorbing layer 9, and the light absorbing layer 9 can be made of light absorbing black material. Light emitted from the light emitting layers 7 of the red LED pixel units 400 and the green LED pixel units 500 irradiates on the light absorbing layer 9 and is absorbed by the light absorbing layer 9, so that the light emitted from the light emitting layers 7 of the red LED pixel units 400 and the green LED pixel units 500 is prevented from being emitted to adjacent LED chips, thereby improving the light extraction efficiency of the LED chips and reducing the crosstalk between pixels.

In an alternative embodiment, the size of each second insulating and heat conducting layer 8 in the shape of a right trapezoid is the same, the size of each second insulating and heat conducting layer 8 in the shape of a rectangle is the same, and one half of the sum of the upper bottom and the lower bottom of the second insulating and heat conducting layer 8 in the shape of a right trapezoid is the same as the width of the second insulating and heat conducting layer 8 in the shape of a rectangle, so that the cross-sectional area of the second insulating and heat conducting layer 8 in the shape of a right trapezoid is equal to the cross-sectional area of the second insulating and heat conducting layer 8 in the shape of a rectangle, and the conduction amount of each second insulating and heat conducting layer 8 is the same, thereby balancing the heat dissipation efficiency of each pixel.

Example 2

Referring to fig. 3, embodiment 2 is different from embodiment 1 in that one end of the pad 3 away from the substrate 1 protrudes out of the first insulating and heat conducting layer 4, a groove 52 adapted to the pad 3 is disposed on one side of the electrode 5 facing the first insulating and heat conducting layer 4, an end of the pad 3 protruding out of the first insulating and heat conducting layer 4 is located in the groove 52, the groove 52 is filled with conductive silver paste, and the pad 3 and the electrode 5 are electrically connected through the conductive silver paste. By recessing the electrode 5 with the recess 52, positioning of the electrode 5 on the substrate 1 is facilitated, while facilitating electrical connection between the pad 3 and the electrode 5.

The resistivity of the bonding pad 3 is related to the material thereof, and can be selected according to actual requirements. In an alternative embodiment, the specific resistance of the bonding pad 3 is smaller than that of the electrode 5, and compared with the electrode 5 without the groove 52, the bonding pad 3 with smaller specific resistance is inserted into the groove 52 of the electrode 5, so that the resistance of the current conducting layer can be further reduced, and the brightness uniformity of the display panel can be improved.

Example 3

Referring to fig. 4 to 8, embodiment 3 provides a method for preparing a Micro-LED display panel, including the steps of:

referring to fig. 4, S1: providing a growth substrate 100, and growing an epitaxial layer 200 on the growth substrate 100, wherein the epitaxial layer 200 comprises a second semiconductor layer 201, a quantum well layer 202 and a first semiconductor layer 203 which are sequentially stacked.

In an alternative embodiment, a buffer layer is first formed on the growth substrate 100, and the material of the buffer layer may be, for example, aluminum nitride (AlN) or gallium nitride (GaN). A buffer layer is provided between the growth substrate 100 and the epitaxial layer 200, which is beneficial to improving lattice mismatch between the growth substrate 100 and the epitaxial layer 200.

Referring to fig. 5, the epitaxial layer 200 is etched to form a plurality of spaced boss-shaped light emitting layers 7 and a plurality of spaced column-shaped light emitting layers 7, the boss-shaped light emitting layers 7 correspond to the blue LED pixel units 300, the boss-shaped light emitting layers 7 may be truncated cones or truncated cone-shaped, and the column-shaped light emitting layers 7 correspond to the red LED pixel units 400 or the green LED pixel units 500. Referring to fig. 6, a liquid curable insulating and heat conducting material is filled between adjacent light emitting layers 7 until the insulating and heat conducting material is flush with the first semiconductor layer 203, and after the insulating and heat conducting material is cured, referring to fig. 7, the electrode 5 is prepared in a whole layer on the first semiconductor layer 203 and the insulating and heat conducting material, the electrode 5 is perforated to form a second through hole 51 opposite to the insulating and heat conducting material, and a heat conductor 6 is filled in the second through hole 51.

The electrode 5 can be made by adopting an evaporation process or a sputtering process to make a conductive material on the light-emitting layer 7 and the second insulating and heat-conducting layer 8; a photoresist is coated on the conductive material, the photoresist is patterned by a photolithography process, and the electrode 5 is patterned by a dry etching process or a wet etching process to form the second via hole 51. The electrode 5 can also be manufactured by placing a fine metal mask on the light-emitting layer 7 and the second insulating and heat-conducting layer 8, and evaporating a conductive material onto the upper surfaces of the light-emitting layer 7 and the second insulating and heat-conducting layer 8 to form the electrode 5 with the second through hole 51.

Referring to fig. 8, S2: providing a substrate 1 and an annular enclosure, forming a first through hole 11 by opening a hole in the substrate 1, placing the annular enclosure around the substrate 1, enclosing a synthetic injection space, filling liquid curable insulating and heat conducting materials into the injection space and the first through hole 11, exposing a bonding pad 3 on the substrate 1, forming an insulating and heat conducting body 2 after the insulating and heat conducting materials are cured, and removing the annular enclosure.

Specifically, the insulating heat conductor 2 is formed, and the insulating heat conductor 2 may be ground flat by a chemical mechanical polishing process, so that the height of the insulating heat conductor 2 is consistent with the height of the pad 3.

S3: the light-emitting layer 7 is mounted on the substrate 1 by flip-chip bonding, the electrode 5 is electrically connected to the pad 3, the insulating heat conductor 2 on the substrate 1 is attached to the electrode 5, and the growth substrate 100 is peeled off.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. A Micro-LED display panel, comprising:

the heat-conducting module comprises a substrate (1), wherein the substrate (1) comprises a plurality of spaced mounting areas, a non-mounting area is arranged between every two adjacent mounting areas, first through holes (11) penetrate through the non-mounting areas of the substrate (1), and insulating heat conductors (2) are filled in the first through holes (11);

each mounting area of the substrate (1) is provided with a pad (3), a first insulating heat-conducting layer (4) covers the substrate (1), and the first insulating heat-conducting layer (4) wraps the pad (3) so that one side, away from the substrate (1), of the pad (3) is exposed; and the number of the first and second groups,

the electrode (5) is laminated on the first insulating heat conduction layer (4) and the pad (3), a second through hole (51) opposite to the first insulating heat conduction layer (4) penetrates through the electrode (5), and a heat conductor (6) is filled in the second through hole (51);

a plurality of spaced light emitting layers (7) are arranged on the electrode (5), a second insulating heat conduction layer (8) is filled between every two adjacent light emitting layers (7), the second insulating heat conduction layer (8) is opposite to the second through hole (51), and the side surface, facing the light emitting layers (7), of the second insulating heat conduction layer (8) is not light-transmitting;

each light-emitting layer (7) corresponds to a red LED pixel unit (400) or a green LED pixel unit (500) or a blue LED pixel unit (300), the second insulating heat conduction layer (8) positioned between the blue LED pixel unit (300) and the red LED pixel unit (400) is in a right trapezoid shape on a longitudinal section, the second insulating heat conduction layer (8) positioned between the blue LED pixel unit (300) and the green LED pixel unit (500) is in a right trapezoid shape on a longitudinal section, and the oblique sides of the second insulating heat conduction layer (8) in a right trapezoid shape face the blue LED pixel unit (300); the second insulating and heat conducting layer (8) between the green LED pixel cell (500) and the red LED pixel cell (400) is rectangular in longitudinal cross-section.

2. A Micro-LED display panel according to claim 1, characterized in that the electrode (5) is a conductive reflective layer (10).

3. A Micro-LED display panel according to claim 1, characterized in that the side of the second insulating and heat conducting layer (8) facing the green LED pixel cells (500) is provided with a light absorbing layer (9).

4. A Micro-LED display panel according to claim 1, characterized in that the side of the second insulating and heat conducting layer (8) facing the red LED pixel cell (400) is provided with a light absorbing layer (9).

5. A Micro-LED display panel according to claim 1, characterized in that the side of the second insulating and heat conducting layer (8) facing the blue LED pixel cell (300) is provided with a reflective layer (10).

6. A Micro-LED display panel according to claim 1, wherein the second insulating and heat conducting layer (8) each having a right trapezoid shape has the same size, the second insulating and heat conducting layer (8) each having a rectangular shape has the same size, and one half of the sum of the upper base and the lower base of the second insulating and heat conducting layer (8) each having a right trapezoid shape has the same width as the second insulating and heat conducting layer (8) having a rectangular shape.

7. A Micro-LED display panel according to claim 1, characterized in that the end of the pad (3) facing away from the substrate (1) is arranged protruding out of the first insulating and heat conducting layer (4), the side of the electrode (5) facing the first insulating and heat conducting layer (4) is provided with a recess (52) adapted to the pad (3), and the end of the pad (3) protruding out of the first insulating and heat conducting layer (4) is located in the recess (52).

8. A Micro-LED display panel according to claim 7, characterized in that the pads (3) have a lower resistivity than the electrodes (5).

9. A preparation method of a Micro-LED display panel is characterized by comprising the following steps:

s1, providing a growth substrate (100), growing an epitaxial layer (200) on the growth substrate (100), etching the epitaxial layer (200) to form a plurality of spaced boss-shaped light emitting layers (7) and a plurality of spaced columnar light emitting layers (7), wherein the boss-shaped light emitting layers (7) correspond to blue LED pixel units (300), and the columnar light emitting layers (7) correspond to red LED pixel units (400) or green LED pixel units (500); filling liquid curable insulating heat conduction materials between the adjacent light-emitting layers (7) to be flush with the light-emitting layers (7), preparing a whole layer of electrode (5) on the light-emitting layers (7) and the insulating heat conduction materials after the insulating heat conduction materials are cured, forming a second through hole (51) opposite to the insulating heat conduction materials by opening a hole in the electrode (5), and filling heat conduction materials in the second through hole (51);

s2, providing a substrate (1), forming a first through hole (11) by opening a hole in the substrate (1), filling a liquid curable insulating and heat conducting material on the substrate (1) and in the first through hole (11), exposing a bonding pad (3) on the substrate (1), and curing the insulating and heat conducting material;

s3, the light-emitting layer (7) is mounted on the substrate (1) through flip-chip bonding, the electrode (5) is electrically connected with the bonding pad (3), the insulating heat conduction material on the substrate (1) is attached to the electrode (5), and the growth substrate (100) is peeled.