A manufacturing method of an LED microdisplay module

Abstract

The present invention discloses an LED microdisplay module and a manufacturing method thereof. A glass substrate, a first SOG glass layer, a blue light chip embedding layer, a second SOG glass layer, a green light chip embedding layer, a third SOG glass layer, and a red light chip embedding layer are sequentially arranged from bottom to top. A blue light chip array, a green light chip array, and a red light chip array are respectively embedded in the blue light chip embedding layer, the green light chip embedding layer, and the red light chip embedding layer. The blue light chip array, the green light chip array, and the red light chip array are each composed of N rows and M columns of corresponding chips, and the three types of chips overlap in the vertical direction. The N electrodes of the three types of chips respectively extend to the upper surface of the LED microdisplay module through corresponding N electrode metal columns. The P electrodes of the three types of chips are all connected to the P electrode metal columns and extend to the upper surface of the LED microdisplay module through them. The present invention directly manufactures each pixel point through chip processes, avoiding the mass transfer process. By stacking red, green, and blue chips, the pixel density can be increased.

Description

Technical Field

[0001] The present invention belongs to the field of LED displays, and relates to an LED micro-display module and a manufacturing method thereof. Technical Background

[0002] Micro LED is a new display technology, and each pixel of it is composed of LEDs with a size of several micrometers or dozens of micrometers. Compared with traditional liquid crystal displays and OLEDs, Micro LED has the characteristics of high photoelectric conversion efficiency, high luminous brightness, fast response speed, etc., and has broad application prospects in the fields of VR / AR displays, smart watches, automotive displays, and wearable electronic products. Although Micro LED technology has many advantages, its production capacity, cost, and display quality are still the main factors restricting its wide commercial use. At present, the main technical route of Micro LED is to adopt the method of mass transfer, and through transfer methods such as laser mass transfer and pattern stamp mass transfer, the red, green, and blue chips are respectively transferred to the target substrate. However, such transfer methods have problems such as low transfer efficiency, low yield, and high transfer cost. On the one hand, to a large extent, this transfer method restricts the industrialization of Micro LED; on the other hand, during mass transfer, generally, the red, green, and blue LED chips are placed horizontally and in parallel on the substrate, and usually one red chip, one green chip, and one blue chip form a pixel. In addition, due to the consideration of the driving circuit, when the red, green, and blue are placed horizontally and in parallel, a certain gap needs to be left between the three chips. Therefore, such a chip arrangement method results in the actual display pixel density being only about 1 / 3 of the chip density, which is not conducive to improving the display pixel density. Based on the above reasons, the present invention proposes a micro-display module with a three-dimensional stacking of red, green, and blue without mass transfer. Summary of the Invention

[0003] In order to improve the display pixel density and solve the problems of low mass transfer efficiency and low yield, the core of the present invention lies in proposing a micro-display module with a three-dimensional stacking of red, green, and blue chips realized through chip processing technology and a manufacturing method thereof.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] An LED microdisplay module according to the present invention includes a glass substrate, a first SOG glass layer, a blue chip array, a blue chip embedding layer, a second SOG glass layer, a green chip array, a green chip embedding layer, a third SOG glass layer, a red chip array, and a red chip embedding layer; the glass substrate, the first SOG glass layer, the blue chip embedding layer, the second SOG glass layer, the green chip embedding layer, the third SOG glass layer, and the red chip embedding layer are sequentially arranged from bottom to top; the blue chip array, the green chip array, and the red chip array are respectively embedded in the blue chip embedding layer, the green chip embedding layer, and the red chip embedding layer, and the blue chip array, the green chip array, and the red chip array are each composed of N rows and M columns of corresponding chips, and in the vertical direction, the blue chips in the blue chip array, the green chips in the green chip array, and the red chips in the red chip array overlap; the blue chip N electrode, the green chip N electrode, and the red chip N electrode are respectively fixed on the N-type layers of the blue chip, the green chip, and the red chip, and the three do not overlap in the vertical direction. The blue chip N electrode is connected to the bottom of the blue chip N electrode metal column, the green chip N electrode is connected to the bottom of the green chip N electrode metal column, and the red chip N electrode is connected to the bottom of the red chip N electrode metal column. The tops of the blue chip N electrode metal column, the green chip N electrode metal column, and the red chip N electrode metal column all extend to the upper surface of the LED microdisplay module; the blue chip P electrode, the green chip P electrode, and the red chip P electrode are respectively fixed on the P-type layers of the blue chip, the green chip, and the red chip, and the three are all connected to the P electrode metal column, and the top of the P electrode metal column extends to the upper surface of the LED microdisplay module.

[0006] The blue chip according to the present invention includes a blue chip body, a blue chip P electrode, and a blue chip N electrode. The blue chip N electrode is fixed at a corner of the upper N-type layer of the blue chip body. The N-type layer and the multiple quantum well layer at a corner of the blue chip body are removed to expose the P-type layer, and the blue chip P electrode B01 is fixed on the exposed P-type layer of the blue chip; the green chip includes a green chip body, a green chip P electrode, a green chip N electrode, and a green chip P electrode notch. The green chip N electrode is fixed at a corner of the upper N-type layer of the green chip body. The N-type layer and the multiple quantum well layer at a corner of the green chip body are removed to expose the P-type layer, and the green chip P electrode is fixed on the exposed P-type layer of the green chip. A green chip P electrode notch is formed at the outer corner of the green chip P electrode and the lower green chip P-type layer; the red chip body, the red chip P electrode, the red chip N electrode, and the red chip P electrode notch. The red chip N electrode is fixed at a corner of the upper N-type layer of the red chip body. The N-type layer and the multiple quantum well layer at a corner of the red chip body are removed to expose the P-type layer, and the red chip P electrode is fixed on the exposed P-type layer of the red chip. A red chip P electrode notch is formed at the outer corner of the red chip P electrode and the lower red chip P-type layer.

[0007] The N-electrode metal column of the blue light chip involved in the present invention includes a first metal column of the N-electrode of the blue light chip, a second metal column of the N-electrode of the blue light chip, and a third metal column of the N-electrode of the blue light chip, which are connected in sequence from bottom to top. The N-electrode of the blue light chip is connected to the bottom of the first metal column of the N-electrode of the blue light chip. The first metal column of the N-electrode of the blue light chip is embedded in the embedding layer of the blue light chip, and the top of the first metal column of the N-electrode of the blue light chip is flush with the top of the embedding layer of the blue light chip. The second metal column of the N-electrode of the blue light chip is embedded in the second SOG glass layer and the embedding layer of the green light chip, and the bottom of the second metal column of the N-electrode of the blue light chip is flush with the bottom of the second SOG glass layer. The top of the second metal column of the N-electrode of the blue light chip is flush with the embedding layer of the green light chip. The third metal column of the N-electrode of the blue light chip is embedded in the third SOG glass layer and the embedding layer of the red light chip, and the bottom of the third metal column of the N-electrode of the blue light chip is flush with the bottom of the third SOG glass layer. The top of the third metal column of the N-electrode of the blue light chip is flush with the top of the embedding layer of the red light chip.

[0008] Preferably, blue light, green light, and red light absorbing materials are respectively doped in the embedding layer of the blue light chip, the embedding layer of the green light chip, and the embedding layer of the red light chip.

[0009] The N-electrode metal column of the green light chip involved in the present invention includes a first metal column of the N-electrode of the green light chip and a second metal column of the electrode of the green light chip, which are connected in sequence from bottom to top. The N-electrode of the green light chip is connected to the bottom of the first metal column of the N-electrode of the green light chip. The first metal column of the N-electrode of the green light chip is embedded in the embedding layer of the green light chip, and the top of the first metal column of the N-electrode of the green light chip is flush with the top of the embedding layer of the green light chip. The second metal column of the electrode of the green light chip is embedded in the third SOG glass layer and the embedding layer of the red light chip, and the bottom of the second metal column of the electrode of the green light chip is flush with the bottom of the third SOG glass layer. The top of the second metal column of the electrode of the green light chip is flush with the top of the embedding layer of the red light chip.

[0010] The N-electrode metal column of the red light chip involved in the present invention is embedded in the embedding layer of the red light chip. The N-electrode of the red light chip is connected to the bottom of the N-electrode metal column of the red light chip, and the top of the N-electrode metal column of the red light chip is flush with the embedding layer of the red light chip.

[0011] The P-electrode metal column involved in the present invention includes a blue-chip P-electrode metal column, a green-chip P-electrode metal column, and a red-chip P-electrode metal column connected in sequence from bottom to top; the blue-chip P-electrode is connected to the bottom of the blue-chip P-electrode metal column, the blue-chip P-electrode metal column is embedded in the blue-chip embedding layer, and the top of the blue-chip P-electrode metal column is flush with the top of the blue-chip embedding layer; the green-chip P-electrode metal column is embedded in the second SOG glass layer and the green-chip embedding layer, the bottom and top of the green-chip P-electrode metal column are respectively flush with the bottom of the second SOG glass layer and the top of the green-chip embedding layer, and the green-chip P-electrode is embedded in and connected to the stepped notch at the bottom of the green-chip P-electrode metal column; the red-chip P-electrode metal column is embedded in the third SOG glass layer and the red-chip embedding layer, the bottom and top of the red-chip P-electrode metal column are respectively flush with the bottom of the third SOG glass layer and the top of the red-chip embedding layer, and the red-chip P-electrode is embedded in and connected to the stepped notch at the bottom of the red-chip P-electrode metal column.

[0012] The preparation method of the LED microdisplay module of the present invention specifically includes the following steps:

[0013] A preparation method of an LED microdisplay module, characterized in that it specifically includes the following steps:

[0014] (1) Spin-coat liquid glass SOG on a glass substrate, and then attach a blue-light epitaxial wafer grown on a sapphire substrate to the liquid glass SOG. The blue-epitaxial layer surface contacts and adheres to the liquid glass SOG. After adhesion, the liquid glass SOG is cured to form a first SOG glass layer. After curing, the sapphire substrate is peeled off from the blue-light epitaxial wafer;

[0015] (2) Next, fabricate the blue-chip epitaxial layer into a blue-chip array. The blue-chip array is composed of N rows and M columns of blue chips, where N and M are positive integers greater than or equal to 1. Among them, the blue chip includes a blue-chip body, a blue-chip P-electrode, and a blue-chip N-electrode. Remove the N-type layer and multi-quantum well layer at a corner of the blue-chip body to expose the P-type layer, fix the blue-chip P-electrode on the exposed blue-chip P-type layer, and fix the blue-chip N-electrode on the N-type layer at a corner of the blue-chip body.

[0016] (3) Uniformly coat liquid glass SOG in the gaps between the blue-chip arrays and on the surfaces of the blue chips, and then cure the liquid glass SOG to form a blue-chip embedding layer that embeds the blue-chip array. The thickness of the blue-chip embedding layer is greater than the thickness of the blue-chip array.

[0017] Then, the upper surface of the blue light chip embedding layer is etched using photolithography and etching processes, and a first opening and a second opening of the blue light chip embedding layer are formed within the blue light chip embedding layer. The first opening of the blue light chip embedding layer is placed directly above the P electrode of the blue light chip, and the second opening of the blue light chip embedding layer is placed directly above the N electrode of the blue light chip. The P electrode of the blue light chip is exposed at the first opening of the blue light chip embedding layer;

[0018] Next, a metal column of the P electrode of the blue light chip connecting to the P electrode of the blue light chip is formed within the first opening of the blue light chip embedding layer, and a first metal column B12 of the N electrode of the blue light chip connecting to the N electrode of the blue light chip is formed within the second opening of the blue light chip embedding layer. The surface of the sample is ground and polished;

[0019] (4) Next, spin-on glass (SOG) is spin-coated on the surface of the blue light chip embedding layer, and then a green light epitaxial wafer grown on a beryl substrate is bonded to the SOG. The P-type surface of the green light epitaxial wafer is bonded to the SOG. Next, the SOG is cured to form a second SOG glass layer, and then the beryl substrate on the green light epitaxial wafer is peeled off by means of laser lift-off;

[0020] (5) Next, the green light epitaxial wafer is made into a green light chip array. The green light chip array is composed of N rows and M columns of green light chips. Each green light chip in the green light chip array is aligned with a blue light chip in the blue light chip array. Among them, the green light chip G includes a green light chip body, a P electrode of the green light chip, an N electrode of the green light chip, a window opening of the green light chip, and a notch of the P electrode of the green light chip. A window opening of the green light chip and a notch of the P electrode of the green light chip are respectively formed on the outer periphery of the green light chip body. The window opening of the green light chip and the notch of the P electrode of the green light chip penetrate the entire green light chip body. The N-type layer and the green light multiple quantum well layer near the notch of the P electrode of the green light chip are removed to expose the P-type layer. The P electrode of the green light chip is fixed on the exposed P-type layer of the green light chip. The notch of the P electrode of the green light chip is placed directly above the metal column of the P electrode of the blue light chip, and the window opening of the green light chip is located directly above the first metal column of the N electrode of the blue light chip. The N electrode G02 of the green light chip is fixed on the upper part of the N-type layer of the green light chip body;

[0021] (6) Next, uniformly coat the liquid glass SOG in the gaps between the green light chip arrays and on the surfaces of the green light chips, and then cure the liquid glass SOG to form a green light chip embedding layer that embeds the green light chip arrays. The thickness of the green light chip embedding layer is greater than the thickness of the green light chip arrays. Then, perform photolithography and etching on the upper surface of the green light chip embedding layer to form a first opening, a second opening, and a third opening of the green light chip embedding layer above each green light chip. The first opening of the green light chip embedding layer is located directly above the P electrode of the green light chip and the metal column of the P electrode of the blue light chip. The P electrode of the green light chip and the metal column of the P electrode of the blue light chip are exposed at the first opening of the green light chip embedding layer. A metal column of the P electrode of the green light chip that connects the P electrode of the green light chip and the metal column of the P electrode of the blue light chip is formed within the first opening of the green light chip embedding layer. The second opening of the green light chip embedding layer is located directly above the N electrode G02 of the green light chip. The N electrode of the green light chip is exposed at the second opening of the green light chip embedding layer. A first metal column of the N electrode of the green light chip that connects the N electrode of the green light chip is formed within the second opening of the green light chip embedding layer. The third opening of the green light chip embedding layer is located directly above the first metal column B12 of the N electrode of the blue light chip and partially coincides with the window opening part of the green light chip. The first metal column of the N electrode of the blue light chip is exposed at the third opening of the green light chip embedding layer. A second metal column of the N electrode of the blue light chip that connects the first metal column of the N electrode of the blue light chip is formed within the third opening of the green light chip embedding layer. The second metal column of the N electrode of the blue light chip does not contact the green light chip. Then, planarize the surface of the green light chip embedding layer;

[0022] (7) Next, spin - coat the liquid glass SOG on the surface of the green light chip embedding layer, bond the red light epitaxial wafer grown on the GaAs substrate to the liquid glass SOG. After spin - coating, bond the P - type part of the red light epitaxial wafer to the liquid glass SOG, and then cure the liquid glass SOG to form a third SOG glass layer. Next, use the wet etching method to remove the GaAs substrate of the red light epitaxial wafer;

[0023] (8) Then, a red light chip array is fabricated. The red light chip array is composed of N rows and M columns of red light chips. Each red light chip in the red light chip array is opposite to a green light chip in the green light chip array. Among them, the red light chip R includes a red light chip body, a red light chip P electrode, a red light chip N electrode, a first opening window of the red light chip, a second opening window of the red light chip, and a notch of the red light chip P electrode. A notch of the red light chip P electrode, a first opening window of the red light chip, and a second opening window of the red light chip are respectively opened on the outer periphery of the red light chip body. The notch of the red light chip P electrode, the first opening window of the red light chip, and the second opening window of the red light chip penetrate the entire red light chip body. The N-type layer and the quantum well layer of the red light chip near the notch of the red light chip P electrode are removed to expose the P-type layer. The red light chip P electrode is fixed on the exposed P-type layer of the red light chip. The notch of the red light chip P electrode is placed directly above the metal column of the green light chip P electrode. The first opening window of the red light chip is located directly above the second metal column of the blue light chip N electrode. The second opening window of the red light chip is located directly above the first metal column of the green light chip N electrode. The red light chip N electrode is fixed on the upper part of the N-type layer of the red light chip body;

[0024] (9) Next, liquid glass SOG is evenly coated in the gaps between the red light chip arrays and on the surfaces of the red light chips. Then, the liquid glass SOG is cured to form a red light chip embedding layer that embeds the red light chip array. The thickness of the red light chip embedding layer is greater than the thickness of the red light chip array. Then, photolithography and etching are performed on the red light chip embedding layer. Through etching, a first opening hole of the red light chip embedding layer, a second opening hole of the red light chip embedding layer, a third opening hole of the red light chip embedding layer, and a fourth opening hole of the red light chip embedding layer are formed above each red light chip. The first opening hole of the red light chip embedding layer exposes the red light chip P electrode and the metal column of the green light chip P electrode. A metal column of the red light chip P electrode connecting the red light chip P electrode and the metal column of the green light chip P electrode is sequentially formed at the first opening hole of the red light chip embedding layer. The second opening hole of the red light chip embedding layer partially coincides with the second opening window of the red light chip. The second opening hole of the red light chip embedding layer exposes the first metal column of the green light chip N electrode. A second metal column of the green light chip electrode connecting the first metal column of the green light chip N electrode is sequentially formed in the second opening hole of the red light chip embedding layer. The second metal column of the green light chip electrode does not contact the red light chip. The third opening hole of the red light chip embedding layer partially coincides with the first opening window of the red light chip. The third opening hole of the red light chip embedding layer exposes the second metal column of the blue light chip N electrode. A third metal column of the blue light chip N electrode connecting the second metal column of the blue light chip N electrode is formed in the third opening hole of the red light chip embedding layer. The third metal column of the blue light chip N electrode does not contact the red light chip. The fourth opening hole of the red light chip embedding layer is arranged directly above the red light chip N electrode, exposing the red light chip N electrode. A metal column of the red light chip N electrode connecting the red light chip N electrode is formed in the fourth opening hole of the red light chip embedding layer. Next, the surface of the red light chip embedding layer is ground and polished.

[0025] The present invention aims to solve the problems of low efficiency and low yield in the mass transfer of Micro-LEDs and to increase the display pixel density. A three-dimensional stacked Micro-LED manufacturing method is proposed. Compared with the prior art, the present invention has the following beneficial effects: 1. Each pixel is directly fabricated through a chip process, avoiding the mass transfer process; 2. By stacking red, green, and blue chips, the pixel density can be increased; 3. The fabricated micro-display array module can be assembled into a suitable size according to actual needs during subsequent use. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figures 1-15 It is a process flow diagram of the preparation method of the LED micro-display module of the present invention.

[0027] Figure 16 It is a corresponding relationship diagram between the blue chip, green chip, and red chip in the LED micro-display module of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] To make the objectives and technical solutions of the implementation of the present invention clearer, the technical solutions of the present invention will be further described below with reference to the accompanying drawings in the embodiments. However, the description of the present invention is not limited to the following.

[0029] Embodiment 1

[0030] As Figures 1-15As shown in the figure, an LED microdisplay module according to the present invention includes a glass substrate 1, a first SOG glass layer 2, a blue light chip array, a blue light chip embedding layer 5, a second SOG glass layer 6, a green light chip array, a green light chip embedding layer 7, a third SOG glass layer 8, a red light chip array, and a red light chip embedding layer 9; the glass substrate 1, the first SOG glass layer 2, the blue light chip embedding layer 5, the second SOG glass layer 6, the green light chip embedding layer 7, the third SOG glass layer 8, and the red light chip embedding layer 9 are sequentially arranged from bottom to top; the blue light chip array, the green light chip array, and the red light chip array are respectively embedded in the blue light chip embedding layer 5, the green light chip embedding layer 7, and the red light chip embedding layer 9, and the blue light chip array, the green light chip array, and the red light chip array are each composed of N rows and M columns of corresponding chips, and in the vertical direction (in the front projection view), the blue light chips in the blue light chip array, the green light chips in the green light chip array, and the red light chips in the red light chip array overlap; the blue light chip N electrodes, the green light chip N electrodes, and the red light chip N electrodes are respectively fixed on the N-type layers of the blue light chips, the green light chips, and the red light chips, and the three do not overlap in the vertical direction. The blue light chip N electrode is connected to the bottom of the blue light chip N electrode metal column, the green light chip N electrode is connected to the bottom of the green light chip N electrode metal column, the red light chip N electrode is connected to the bottom of the red light chip N electrode metal column, and the tops of the blue light chip N electrode metal column, the green light chip N electrode metal column, and the red light chip N electrode metal column all extend to the upper surface of the LED microdisplay module; the blue light chip P electrodes, the green light chip P electrodes, and the red light chip P electrodes are respectively fixed on the P-type layers of the blue light chips, the green light chips, and the red light chips, and the three are all connected to the P electrode metal column, and the top of the P electrode metal column extends to the upper surface of the LED microdisplay module.

[0031] The blue light chip B involved in the present invention includes a blue light chip body, a blue light chip P electrode B01, and a blue light chip N electrode B02. The blue light chip N electrode B02 is fixed at a corner of the N-type layer on the upper part of the blue light chip body. The N-type layer and the multi-quantum well layer at a corner of the blue light chip body are removed to expose the P-type layer, and the blue light chip P electrode B01 is fixed on the exposed P-type layer of the blue light chip; the green light chip G includes a green light chip body, a green light chip P electrode G01, a green light chip N electrode G02, and a green light chip P electrode notch G04. The green light chip N electrode G02 is fixed at a corner of the N-type layer on the upper part of the green light chip body. The N-type layer and the multi-quantum well layer at a corner of the green light chip body are removed to expose the P-type layer, and the green light chip P electrode G01 is fixed on the exposed P-type layer of the green light chip. A green light chip P electrode notch G04 is formed at the outer corner of the green light chip P electrode G01 and the lower P-type layer of the green light chip; the red light chip body, a red light chip P electrode R01, a red light chip N electrode R02, and a red light chip P electrode notch R05. The red light chip N electrode R02 is fixed at a corner of the N-type layer on the upper part of the red light chip body. The N-type layer and the multi-quantum well layer at a corner of the red light chip body are removed to expose the P-type layer, and the red light chip P electrode R01 is fixed on the exposed P-type layer of the red light chip. A red light chip P electrode notch R05 is formed at the outer corner of the red light chip P electrode R01 and the lower P-type layer of the red light chip.

[0032] The blue light chip N electrode metal column involved in the present invention includes a blue light chip N electrode first metal column B12, a blue light chip N electrode second metal column B22, and a blue light chip N electrode third metal column B32 connected in sequence from bottom to top. The blue light chip N electrode is connected to the bottom of the blue light chip N electrode first metal column B12. The blue light chip N electrode first metal column B12 is embedded in the blue light chip embedding layer 5, and the top of the blue light chip N electrode first metal column B12 is flush with the top of the blue light chip embedding layer 5. The blue light chip N electrode second metal column B22 is embedded in the second SOG glass layer 6 and the green light chip embedding layer 7, and the bottom of the blue light chip N electrode second metal column B22 is flush with the bottom of the second SOG glass layer 6. The top of the blue light chip N electrode second metal column B22 is flush with the green light chip embedding layer 7. The blue light chip N electrode third metal column B32 is embedded in the third SOG glass layer 8 and the red light chip embedding layer 9, and the bottom of the blue light chip N electrode third metal column B32 is flush with the third SOG glass layer 8. The top of the blue light chip N electrode third metal column B32 is flush with the top of the red light chip embedding layer 9. The materials of the N electrodes of the blue light chip, the green light chip, and the red light chip are Ti / Al / Ni / Au, and the materials of the P electrodes of the blue light chip, the green light chip, and the red light chip are Ni / Au or Ni / Pd / Au.

[0033] Preferably, blue light, green light, and red light absorbing materials are doped in the blue light chip embedding layer, the green light chip embedding layer, and the red light chip embedding layer respectively.

[0034] Specifically, the cross-sectional sizes of the N electrode of the blue light chip, the first metal column B12 of the N electrode of the blue light chip, the second metal column B22 of the N electrode of the blue light chip, and the third metal column B32 of the N electrode of the blue light chip are the same.

[0035] The N electrode metal column of the green light chip involved in the present invention includes a first metal column G12 of the N electrode of the green light chip and a second metal column G22 of the green light chip electrode connected in sequence from bottom to top. The N electrode of the green light chip is connected to the bottom of the first metal column G12 of the N electrode of the green light chip. The first metal column G12 of the N electrode of the green light chip is embedded in the embedding layer 7 of the green light chip. The top of the first metal column G12 of the N electrode of the green light chip is flush with the top of the embedding layer 7 of the green light chip. The second metal column G22 of the green light chip electrode is embedded in the third SOG glass layer 8 and the embedding layer 9 of the red light chip, and the bottom of the second metal column G22 of the green light chip electrode is flush with the bottom of the third SOG glass layer 8, and the top of the second metal column G22 of the green light chip electrode is flush with the top of the embedding layer 9 of the red light chip.

[0036] Specifically, the cross-sectional sizes of the N electrode of the green light chip, the first metal column G12 of the N electrode of the green light chip, and the second metal column G22 of the green light chip electrode are the same.

[0037] The N electrode metal column of the red light chip involved in the present invention is embedded in the embedding layer 9 of the red light chip. The N electrode of the red light chip is connected to the bottom of the N electrode metal column of the red light chip, and the top of the N electrode metal column of the red light chip is flush with the embedding layer 9 of the red light chip.

[0038] Specifically, the cross-sectional sizes of the N electrode of the red light chip and the N electrode metal column of the red light chip are the same.

[0039] The P electrode metal column involved in this embodiment includes a P electrode metal column of the blue light chip, a P electrode metal column of the green light chip, and a P electrode metal column of the red light chip connected in sequence from bottom to top; the P electrode of the blue light chip is connected to the bottom of the P electrode metal column of the blue light chip, the P electrode metal column of the blue light chip is embedded in the embedding layer 5 of the blue light chip, and the top of the P electrode metal column of the blue light chip is flush with the top of the embedding layer 5 of the blue light chip; the P electrode metal column of the green light chip is embedded in the second SOG glass layer 6 and the embedding layer 7 of the green light chip, the bottom and the top of the P electrode metal column of the green light chip are respectively flush with the bottom of the second SOG glass layer 6 and the top of the embedding layer 7 of the green light chip, and the P electrode of the green light chip is embedded in the stepped notch at the bottom of the P electrode metal column of the green light chip and is connected thereto; the P electrode metal column of the red light chip is embedded in the third SOG glass layer 8 and the embedding layer 9 of the red light chip, the bottom and the top of the P electrode metal column of the red light chip are respectively flush with the bottom of the third SOG glass layer 8 and the top of the embedding layer 9 of the red light chip, and the P electrode of the red light chip is embedded in the stepped notch at the bottom of the P electrode metal column of the red light chip and is connected thereto.

[0040] The preparation method of the LED microdisplay module of the present invention specifically includes the following steps:

[0041] (1) As shown in Figure 1 and 2 , spin-coat liquid glass SOG on the glass substrate 1, and then attach the blue light epitaxial wafer 3 grown on the sapphire substrate 4 to the liquid glass SOG. The P-type surface of the blue light epitaxial layer is in contact with and attached to the liquid glass SOG. After attachment, the liquid glass SOG is cured to form the first SOG glass layer 2. After curing, the sapphire substrate 4 is peeled off from the blue light epitaxial wafer 3.

[0042] It should be noted that: the curing method of the liquid glass SOG is to place the sample in a vacuum oven and cure the liquid glass SOG to form a SOG glass layer, and the curing temperature is 100°C - 800°C.

[0043] It should be noted that: the sapphire substrate 4 is peeled off from the blue light epitaxial wafer 3 by laser lift-off.

[0044] It should be noted that: among them, the blue light epitaxial layer 3 includes a blue light epitaxial wafer P-type layer 301, a blue light multiple quantum well layer, and a blue light epitaxial wafer N-type layer 302 arranged in sequence from bottom to top. The surface of the blue light epitaxial layer P-type layer 301 is in contact with and attached to the first SOG glass layer 2.

[0045] (2) As shown in Figure 3 and 4 , next, through processes such as photolithography, dry etching, magnetron sputtering, and annealing, the blue light chip epitaxial layer 3 is made into a blue light chip array. The blue light chip array is composed of N rows and M columns of blue light chips, where N and M are positive integers greater than or equal to 1. Among them, the blue light chip B includes a blue light chip body, a blue light chip P electrode B01, and a blue light chip N electrode B02. Remove the N-type layer and multiple quantum well layer at a corner of the blue light chip body to expose the P-type layer, fix the blue light chip P electrode B01 on the exposed P-type layer of the blue light chip, and fix the blue light chip N electrode B02 on the N-type layer at a corner of the blue light chip body.

[0046] The blue light chip P electrode B01 and the blue light chip N electrode B02 respectively form ohmic contacts with P-type GaN and N-type GaN. The material of the N electrode is Ti / Al / Ni / Au, and the material of the P electrode is Ni / Au or Ni / Pd / Au.

[0047] It should be noted that: the cross-section of the blue light chip is square, rectangular or other geometric shapes, the cross-section length is 5 - 500 microns, and the distance between adjacent two blue light chips is 5 - 500 microns.

[0048] After the sapphire substrate is peeled off by laser, photoresist is coated above the N-type epitaxial layer 302 of the blue light chip, and then the photoresist is exposed using a mask template with N rows and M columns of openings, where the openings are the exposure areas. Then the sample is developed, and after removing the non-exposed area of the photoresist, part of the N-type epitaxial layer 302 is exposed. Next, the exposed epitaxial layer is etched completely until the first SOG glass 2. After etching, all the photoresist is removed, thereby forming an epitaxial layer array of N rows and M columns.

[0049] Next, photoresist is coated above and on the sides of the epitaxial layer array, and then the photoresist is exposed using a mask template. After exposure, the photoresist is developed. After development, part of the epitaxial layer is exposed, and then the exposed epitaxial layer is etched until the P-type epitaxial layer 301 is exposed. Next, the sides of the N-type epitaxial layer 302 and the multiple quantum wells formed after etching are passivated with SiO2 to form side protection layers, and finally all the photoresist is removed. Next, the sample is coated with photoresist again, exposed, developed, and etched until the P-type epitaxial layer 301 is exposed. Then, Ni / Au or Ni / Pd / Au is sputtered sequentially on the P-type epitaxial layer 301, and finally all the photoresist is removed. After removing the photoresist, the sample is annealed to form the P electrode B01.

[0050] Next, photoresist is coated above and on the sides of the epitaxial layer array, and then the photoresist is exposed using a mask template. After exposure, the photoresist is developed to expose part of the N-type epitaxial layer 302, and then Ti / Al / Ti / Au metal is sputtered sequentially on the exposed N-type epitaxial layer 302. Next, all the photoresist is removed. Finally, the sample is annealed to form the N electrode B02.

[0051] (3)As Figure 5 and 6 shown, liquid glass SOG is uniformly coated in the gaps between the blue light chip arrays and on the surface of the blue light chips, and then the liquid glass SOG is cured to form a blue light chip embedding layer 5 that embeds the blue light chip arrays. The thickness of the blue light chip embedding layer 5 is greater than the thickness of the blue light chip arrays.

[0052] Then, the upper surface of the blue light chip embedding layer 5 is etched using photolithography and etching processes, and a first opening of the blue light chip embedding layer and a second opening of the blue light chip embedding layer are formed in the blue light chip embedding layer 5. The first opening of the blue light chip embedding layer is placed directly above the P electrode B01 of the blue light chip, and the second opening of the blue light chip embedding layer is placed directly above the N electrode B02 of the blue light chip. The P electrode B01 of the blue light chip is exposed at the first opening of the blue light chip embedding layer.

[0053] Next, deposit a TiN film and tungsten metal in sequence within the first opening of the blue light chip embedding layer to form a blue light chip P electrode metal column B11 connecting to the blue light chip P electrode B01. Deposit a TiN film and tungsten metal within the second opening of the blue light chip embedding layer to form a first blue light chip N electrode metal column B12 connecting to the blue light chip N electrode B02. The cross-sectional sizes of the first opening of the blue light chip embedding layer and the blue light chip P electrode metal column B11 are the same. The cross-section of the first opening of the blue light chip embedding layer is slightly smaller than that of the blue light chip P electrode B01. The cross-sectional sizes of the second opening of the blue light chip embedding layer, the first blue light chip N electrode metal column B12, and the blue light chip N electrode B02 are the same. Next, grind and polish the surface of the sample to remove the tungsten metal and TiN on the surface of the blue light chip embedding layer 5, achieving the planarization of the sample surface.

[0054] It should be noted that: to reduce the optical crosstalk between pixels, a blue light absorbing material can be doped within the blue light chip embedding layer 5. The blue light absorbing material can absorb blue light and light with wavelengths shorter than blue light, and the blue light absorbing material allows light with wavelengths longer than blue light to pass through.

[0055] (4) As Figure 7 shown, next, spin-coat liquid glass SOG on the surface of the blue light chip embedding layer 5, and then attach the green light epitaxial wafer grown on the emerald substrate to the liquid glass SOG. The P-type surface of the green light epitaxial wafer is attached to the liquid glass SOG. Next, cure the liquid glass SOG to form a second SOG glass layer 6, and then use the laser lift-off method to peel off the emerald substrate on the green light epitaxial wafer.

[0056] It should be noted that the sapphire epitaxial wafer includes a P-type layer of the green light epitaxial wafer, a green light multiple quantum well layer, and an N-type layer of the green light epitaxial wafer arranged in sequence from bottom to top. The P-type layer of the green light epitaxial wafer is attached to the second SOG glass layer 6.

[0057] (5) As Figure 8 and 9As shown in the figure, next, by means of photolithography, development, etching, metal deposition, annealing, etc., the green light epitaxial wafer is made into a green light chip array. The green light chip array is composed of N rows and M columns of green light chips. Each green light chip in the green light chip array is opposite to a blue light chip in the blue light chip array. Among them, the green light chip G includes a green light chip body, a green light chip P electrode G01, a green light chip N electrode G02, a green light chip opening window G03, and a green light chip P electrode notch G04. A green light chip opening window G03 and a green light chip P electrode notch G04 are respectively opened on the outer periphery of the green light chip body. The green light chip opening window G03 and the green light chip P electrode notch G04 penetrate the entire green light chip body. The N-type layer and the green light multiple quantum well layer of the green light chip near the green light chip P electrode notch G04 are removed to expose the P-type layer. The green light chip P electrode G01 is fixed on the exposed P-type layer of the green light chip. The green light chip P electrode notch G04 is placed directly above the blue light chip P electrode metal column B11, and the cross-sectional size of the green light chip P electrode notch G04 is equal to the cross-sectional size of the blue light chip P electrode metal column B11. The green light chip opening window G03 is located directly above the first metal column B12 of the blue light chip N electrode. The cross-sectional size of the green light chip opening window G03 is larger than the cross-sectional size of the first metal column B12 of the blue light chip N electrode. The green light chip N electrode G02 is fixed on the upper part of the N-type layer of the green light chip body.

[0058] It should be noted that: the material of the green light chip N electrode is Ti / Al / Ni / Au, and the material of the green light chip P electrode is Ni / Au or Ni / Pd / Au.

[0059] (6) As Figure 10 and 11 shown in the figure, next, liquid glass SOG is evenly coated on the gaps between the green light chip arrays and the surfaces of the green light chips, and then the liquid glass SOG is cured to form a green light chip embedding layer 7 that embeds the green light chip array. The thickness of the green light chip embedding layer 7 is greater than the thickness of the green light chip array.

[0060] Then, photolithography and etching are performed on the upper surface of the green light chip embedding layer 7 to form a first opening, a second opening, and a third opening of the green light chip embedding layer above each green light chip. The first opening of the green light chip embedding layer is located directly above the P electrode G01 of the green light chip and the P electrode metal column B11 of the blue light chip. The first opening of the green light chip embedding layer exposes the P electrode G01 of the green light chip and the P electrode metal column B11 of the blue light chip. A TiN film and tungsten metal are sequentially deposited in the first opening of the green light chip embedding layer to form a green light chip P electrode metal column G11 connecting the P electrode G01 of the green light chip and the P electrode metal column B11 of the blue light chip. The second opening of the green light chip embedding layer is located directly above the N electrode G02 of the green light chip. The cross-sectional size of the second opening of the green light chip embedding layer is equal to the cross-sectional size of the N electrode G02 of the green light chip. The second opening of the green light chip embedding layer exposes the N electrode G02 of the green light chip. A TiN film and tungsten metal are sequentially deposited in the second opening of the green light chip embedding layer to form a first green light chip N electrode metal column G12 connecting the N electrode G02 of the green light chip.

[0061] The third opening of the green light chip embedding layer is located directly above the first N electrode metal column B12 of the blue light chip, partially overlapping with the green light chip opening window G03. The cross-sectional size of the third opening of the green light chip embedding layer is equal to the cross-sectional size of the first N electrode metal column B12 of the blue light chip and smaller than the cross-sectional size of the green light chip opening window G03. The third opening of the green light chip embedding layer exposes the first N electrode metal column B12 of the blue light chip. A TiN film and tungsten metal are sequentially deposited in the third opening of the green light chip embedding layer to form a second N electrode metal column B22 (or G13) of the blue light chip connecting the first N electrode metal column B12 of the blue light chip. The second N electrode metal column B22 of the blue light chip does not contact the green light chip. Then, by means of grinding and polishing, the tungsten metal and TiN film on the surface of the green light chip embedding layer 7 are removed to planarize the surface of the green light chip embedding layer 7.

[0062] It should be noted that: to reduce the optical crosstalk between pixels, a green light absorbing material can be doped in the green light chip embedding layer 7. The green light absorbing material can absorb green light and light with a wavelength shorter than green light, and the green light absorbing material allows light with a wavelength longer than green light to pass through.

[0063] (7) As Figure 12As shown in the figure, next, spin-coat liquid glass SOG on the surface of the green light chip embedding layer 7, attach the red light epitaxial wafer grown on the GaAs substrate to the liquid glass SOG. After spin-coating, attach the P-type part of the red light epitaxial wafer to the liquid glass SOG, and then cure the liquid glass SOG to form the third SOG glass layer 8. Next, use the method of wet etching to remove the GaAs substrate of the red light epitaxial wafer. After removing the GaAs substrate, evaporate a layer of metal Ag on the N-type layer of the red light epitaxial layer to form a metal layer. The metal Ag can reflect the red light emitted by the active region of the red light chip to increase the brightness of the red light.

[0064] It should be noted that: put the sample into the wet etching solution to remove the GaAs substrate of the red light epitaxial wafer.

[0065] It should be noted that: the red light epitaxial wafer includes a red light epitaxial wafer P-type layer, a red light multi-quantum well layer, and a red light epitaxial wafer N-type layer arranged in sequence from bottom to top. The surface of the red light epitaxial wafer P-type layer is in contact and attached to the third SOG glass layer 8.

[0066] (8) As Figure 12 and 13 shown in the figure, then use methods such as photolithography, etching, metal deposition, and annealing to fabricate a red light chip array. The red light chip array is composed of N rows and M columns of red light chips. Each red light chip in the red light chip array is directly opposite to a green light chip in the green light chip array. Among them, the red light chip R includes a red light chip body, a red light chip P electrode R01, a red light chip N electrode R02, a red light chip first opening R03, a red light chip second opening R04, and a red light chip P electrode notch R05. A red light chip P electrode notch R05, a red light chip first opening R03, and a red light chip second opening R04 are respectively opened on the outer periphery of the red light chip body. The red light chip P electrode notch R05, the red light chip first opening R03, and the red light chip second opening R04 penetrate the entire red light chip body. Remove the N-type layer and quantum well layer of the red light chip near the red light chip P electrode notch R05 to expose the P-type layer, and fix the red light chip P electrode R01 on the exposed P-type layer of the red light chip. The red light chip P electrode notch R05 is placed directly above the green light chip P electrode metal column G11, and the cross-sectional size of the red light chip P electrode notch R05 is equal to the cross-sectional size of the green light chip P electrode metal column G11. The red light chip first opening R03 is located directly above the blue light chip N electrode second metal column B22, and the cross-sectional size of the red light chip first opening R03 is larger than the cross-sectional size of the blue light chip N electrode second metal column B22. The red light chip second opening R04 is located directly above the green light chip N electrode first metal column G12, and the cross-sectional size of the red light chip second opening R04 is larger than the cross-sectional size of the green light chip N electrode first metal column G12. The red light chip N electrode R02 is fixed on the upper part of the N-type layer of the red light chip body.

[0067] As shown in Figure 14 and 15 , next, liquid glass SOG is uniformly coated on the gaps between the red light chip arrays and on the surfaces of the red light chips, and then the liquid glass SOG is cured to form a red light chip embedding layer 9 that embeds the red light chip arrays. The thickness of the red light chip embedding layer 9 is greater than the thickness of the red light chip arrays.

[0068] Then, photolithography and etching are performed on the red light chip embedding layer 9. Through etching, a first opening, a second opening, a third opening, and a fourth opening of the red light chip embedding layer are formed above each red light chip. The first opening of the red light chip embedding layer exposes the P electrode R01 of the red light chip and the P electrode metal column G11 of the green light chip. A TiN film and then tungsten metal are sequentially deposited at the first opening of the red light chip embedding layer to form a red light chip P electrode metal column R11 that connects the P electrode R01 of the red light chip and the P electrode metal column G11 of the green light chip. The second opening of the red light chip embedding layer partially overlaps with the second opening window R04 of the red light chip, and the cross-sectional size of the second opening of the red light chip embedding layer is equal to the cross-sectional size of the first metal column G12 of the N electrode of the green light chip and less than the cross-sectional size of the second opening window R04. The second opening of the red light chip embedding layer exposes the first metal column G12 of the N electrode of the green light chip. A TiN film and then tungsten metal are sequentially deposited in the second opening of the red light chip embedding layer to form a second metal column G22 (or R14) of the green light chip electrode that connects the first metal column G12 of the N electrode of the green light chip. The second metal column G22 of the green light chip electrode does not contact the red light chip. The third opening of the red light chip embedding layer partially overlaps with the first opening window R03 of the red light chip, and the cross-sectional size of the third opening of the red light chip embedding layer is equal to the cross-sectional size of the second metal column B22 of the N electrode of the blue light chip and less than the cross-sectional size of the first opening window R03. The third opening of the red light chip embedding layer exposes the second metal column B22 of the N electrode of the blue light chip. A TiN film and then tungsten metal are sequentially deposited in the third opening of the red light chip embedding layer to form a third metal column B32 (or R13) of the N electrode of the blue light chip that connects the second metal column B22 of the N electrode of the blue light chip. The third metal column B32 of the N electrode of the blue light chip does not contact the red light chip. The fourth opening of the red light chip embedding layer is provided directly above the N electrode R02 of the red light chip, and the cross-sectional size of the fourth opening of the red light chip embedding layer is equal to the cross-sectional size of the N electrode R02 of the red light chip, exposing the N electrode R02 of the red light chip. A TiN film and then tungsten metal are sequentially deposited in the fourth opening of the red light chip embedding layer to form a red light chip N electrode metal column R12 that connects the N electrode R02 of the red light chip;

[0069] Next, the surface of the red light chip embedding layer 9 is ground and polished to remove the metal W and the TiN film on the sample surface and to flatten the sample surface. Finally, metal Sn is deposited on the metal W.

Claims

1. A preparation method of an LED microdisplay module, characterized in that, Specifically, the following steps are included: (1) Spin-coat liquid glass SOG on a glass substrate, and then attach a blue light epitaxial wafer grown on a sapphire substrate to the liquid glass SOG. The blue epitaxial layer surface is in contact and adhered to the liquid glass SOG. After adhesion, the liquid glass SOG is cured to form a first SOG glass layer. After curing, the sapphire substrate is peeled off from the blue light epitaxial wafer; (2) Next, fabricate a blue light chip array from the blue light chip epitaxial layer. The blue light chip array is composed of N rows and M columns of blue light chips, where N and M are positive integers greater than or equal to 1. Among them, the blue light chip includes a blue light chip body, a blue light chip P electrode, and a blue light chip N electrode. Remove the N-type layer and multi-quantum well layer at a corner of the blue light chip body to expose the P-type layer. Fix the blue light chip P electrode on the exposed P-type layer of the blue light chip, and fix the blue light chip N electrode on the N-type layer at a corner of the blue light chip body; (3) Uniformly coat liquid glass SOG in the gaps between the blue light chip arrays and on the surfaces of the blue light chips, and then cure the liquid glass SOG to form a blue light chip embedding layer that embeds the blue light chip array. The thickness of the blue light chip embedding layer is greater than the thickness of the blue light chip array; Then, use photolithography and etching processes to etch the upper surface of the blue light chip embedding layer. A first opening of the blue light chip embedding layer and a second opening of the blue light chip embedding layer are formed in the blue light chip embedding layer. The first opening of the blue light chip embedding layer is located directly above the blue light chip P electrode, and the second opening of the blue light chip embedding layer is located directly above the N electrode of the blue light chip. The blue light chip P electrode is exposed at the first opening of the blue light chip embedding layer; Next, form a blue light chip P electrode metal column connecting the blue light chip P electrode in the first opening of the blue light chip embedding layer, and form a first metal column B12 of the blue light chip N electrode connected to the blue light chip N electrode in the second opening of the blue light chip embedding layer. Grind and polish the surface of the sample; (4) Next, spin-coat liquid glass SOG on the surface of the blue light chip embedding layer, and then attach a green light epitaxial wafer grown on an emerald substrate to the liquid glass SOG. The P-type surface of the green light epitaxial wafer is adhered to the liquid glass SOG. Next, cure the liquid glass SOG to form a second SOG glass layer, and then use laser lift-off to peel off the emerald substrate on the green light epitaxial wafer; (5)Next, the green light epitaxial wafer is made into a green light chip array. The green light chip array is composed of N rows and M columns of green light chips. Each green light chip in the green light chip array is aligned with a blue light chip in the blue light chip array. Among them, the green light chip G includes a green light chip body, a green light chip P electrode, a green light chip N electrode, a green light chip opening window, and a green light chip P electrode notch. A green light chip opening window and a green light chip P electrode notch are respectively opened on the outer periphery of the green light chip body. The green light chip opening window and the green light chip P electrode notch penetrate the entire green light chip body. The N-type layer and the green light multiple quantum well layer of the green light chip near the green light chip P electrode notch are removed to expose the P-type layer. The green light chip P electrode is fixed on the exposed P-type layer of the green light chip. The green light chip P electrode notch is located directly above the P electrode metal column of the blue light chip. The green light chip opening window is located directly above the first metal column of the N electrode of the blue light chip. The green light chip N electrode G02 is fixed on the upper part of the N-type layer of the green light chip body; (6)Next, liquid glass SOG is evenly coated on the gaps between the green light chip arrays and the surfaces of the green light chips. Then, the liquid glass SOG is cured to form a green light chip embedding layer that embeds the green light chip array. The thickness of the green light chip embedding layer is greater than the thickness of the green light chip array. Then, photolithography and etching are performed on the upper surface of the green light chip embedding layer to form a first opening, a second opening, and a third opening of the green light chip embedding layer above each green light chip. The first opening of the green light chip embedding layer is located directly above the P electrode of the green light chip and the P electrode metal column of the blue light chip. The P electrode of the green light chip and the P electrode metal column of the blue light chip are exposed at the first opening of the green light chip embedding layer. A P electrode metal column of the green light chip connecting the P electrode of the green light chip and the P electrode metal column of the blue light chip is formed inside the first opening of the green light chip embedding layer. The second opening of the green light chip embedding layer is located directly above the green light chip N electrode G02. The green light chip N electrode is exposed at the second opening of the green light chip embedding layer. A first metal column of the green light chip N electrode connecting the green light chip N electrode is formed inside the second opening of the green light chip embedding layer. The third opening of the green light chip embedding layer is located directly above the first metal column B12 of the N electrode of the blue light chip and partially coincides with the green light chip opening window. The first metal column of the N electrode of the blue light chip is exposed at the third opening of the green light chip embedding layer. A second metal column of the N electrode of the blue light chip connecting the first metal column of the N electrode of the blue light chip is formed inside the third opening of the green light chip embedding layer. The second metal column of the N electrode of the blue light chip does not contact the green light chip. Then, the surface of the green light chip embedding layer is planarized; (7)Next, liquid glass SOG is spin-coated on the surface of the green light chip embedding layer. The red light epitaxial wafer grown on the GaAs substrate is attached to the liquid glass SOG. After spin-coating, the P-type part of the red light epitaxial wafer is attached to the liquid glass SOG. Then, the liquid glass SOG is cured to form a third SOG glass layer. Next, the GaAs substrate of the red light epitaxial wafer is removed by wet etching; (8) Then, a red light chip array is fabricated. The red light chip array is composed of N rows and M columns of red light chips. Each red light chip in the red light chip array is aligned with a green light chip in the green light chip array. Among them, the red light chip R includes a red light chip body, a red light chip P electrode, a red light chip N electrode, a first opening window of the red light chip, a second opening window of the red light chip, and a notch of the red light chip P electrode. A notch of the red light chip P electrode, a first opening window of the red light chip, and a second opening window of the red light chip are respectively opened on the outer periphery of the red light chip body. The notch of the red light chip P electrode, the first opening window of the red light chip, and the second opening window of the red light chip penetrate the entire red light chip body. The N-type layer and the quantum well layer of the red light chip near the notch of the red light chip P electrode are removed to expose the P-type layer. The red light chip P electrode is fixed on the exposed P-type layer of the red light chip. The notch of the red light chip P electrode is located directly above the metal column of the green light chip P electrode. The first opening window of the red light chip is located directly above the second metal column of the blue light chip N electrode. The second opening window of the red light chip is located directly above the first metal column of the green light chip N electrode. The red light chip N electrode is fixed on the upper part of the N-type layer of the red light chip body; (9) Next, liquid glass SOG is evenly coated in the gaps between the red light chip arrays and on the surfaces of the red light chips. Then, the liquid glass SOG is cured to form a red light chip embedding layer that embeds the red light chip array. The thickness of the red light chip embedding layer is greater than the thickness of the red light chip array. Then, photolithography and etching are performed on the red light chip embedding layer. Through etching, a first opening hole of the red light chip embedding layer, a second opening hole of the red light chip embedding layer, a third opening hole of the red light chip embedding layer, and a fourth opening hole of the red light chip embedding layer are formed above each red light chip. The first opening hole of the red light chip embedding layer exposes the red light chip P electrode and the metal column of the green light chip P electrode. A metal column of the red light chip P electrode connecting the red light chip P electrode and the metal column of the green light chip P electrode is sequentially formed at the first opening hole of the red light chip embedding layer. The second opening hole of the red light chip embedding layer partially overlaps with the second opening window of the red light chip. The second opening hole of the red light chip embedding layer exposes the first metal column of the green light chip N electrode. A second metal column of the green light chip electrode connecting the first metal column of the green light chip N electrode is sequentially formed in the second opening hole of the red light chip embedding layer. The second metal column of the green light chip electrode does not contact the red light chip. The third opening hole of the red light chip embedding layer partially overlaps with the first opening window of the red light chip. The third opening hole of the red light chip embedding layer exposes the second metal column of the blue light chip N electrode. A third metal column of the blue light chip N electrode connecting the second metal column of the blue light chip N electrode is formed in the third opening hole of the red light chip embedding layer. The third metal column of the blue light chip N electrode does not contact the red light chip. The fourth opening hole of the red light chip embedding layer is provided directly above the red light chip N electrode, exposing the red light chip N electrode. A metal column of the red light chip N electrode connecting the red light chip N electrode is formed in the fourth opening hole of the red light chip embedding layer. Next, the surface of the red light chip embedding layer is ground and polished.

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