GaN-based flip-chip common N-pole full-color micro display array and its manufacturing method

Abstract

The present invention discloses a flip-chip common N-pole full-color micro display array based on GaN-based luminescent materials and a manufacturing method thereof, belonging to the technical field of semiconductor light-emitting chips and display applications, comprising a Micro LED array chip and a supporting circuit board, wherein the Micro LED array chip comprises a substrate, a buffer layer, a common N-pole highly doped GaN layer, an N-type GaN conductive layer, a GaN / InGaN multi-quantum well active region, a P-type GaN conductive layer, a P electrode point, an N electrode point, and a secondary luminescent material layer; the supporting circuit board comprises a base plate, an N-pole line and a P-pole line, and the Micro LED array chip and the supporting circuit board are connected by flip-chip bonding; the present invention can reduce the chip electrode area loss by nearly 25%, thereby improving the material utilization rate; it avoids the occupation of the Micro LED chip array area by the metal common N-pole, thereby improving the resolution.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor light-emitting chips and display applications, and in particular relates to a GaN-based flip-chip common N-pole full-color micro-display array and a manufacturing method thereof. Background Art

[0002] Micro LED array devices based on III-V compound semiconductor light-emitting materials are high-density, small-sized two-dimensional arrays integrated on the same display chip, or high-density integrated and arranged small-sized, high-brightness light-emitting diode arrays on the same epitaxial substrate material. The device size is only maintained in the range of a few microns. As an all-solid-state active light-emitting device, it has the characteristics of low operating voltage, high luminous efficiency, fast response speed, stable and reliable performance, and a wide operating temperature range.

[0003] The display array composed of Micro LED has high brightness, ultra-high resolution and color saturation, and each pixel can be driven independently. Therefore, Micro LED micro-display devices have become the mainstream of the future display industry development, which can well meet the application needs of self-luminous micro-display, lighting and communication. In the future, it has broad application prospects in wearable display devices, visible light communication devices, virtual reality display devices and other fields. Micro LED is considered to be the core technology and product of the next generation of display technology. However, there are also some challenges in the production and processing of Micro LED chip display technology, which limits its large-scale application and pushes up the cost of related products. The main problems are as follows:

[0004] 1. After the preparation of the Micro LED array chip with a positive structure is completed, the substrate needs to be peeled off or removed, and then transferred to the supporting circuit for welding in large quantities. This method has the problems of long process time and low yield in process implementation.

[0005] 2. General Micro LED display uses red, green and blue (RGB) three-color chip integration. The three-color chips are integrated using different epitaxial materials and processing technologies, and then undergo three mass transfer integrations. The integration process is complex and the product yield of the integration process is reduced.

[0006] 3. The driving method of Micro LED array chips requires making N electrode points and P electrode points on each chip, and then connecting the N electrode points and P electrode points to the N pole circuit and P pole line of the driving circuit. The chip processing difficulty increases, the process is complicated, and the chip far away from the circuit access point will have line loss due to the increase of on-resistance.

[0007] And the improvement measures of this patent:

[0008] 1. The present invention does not require substrate peeling in the process, and adopts the method of flip-chip welding of the entire Micro LED array chip, and one-time alignment welding, thereby avoiding the problem of low yield of mass transfer of Micro LED single chips caused by mass transfer.

[0009] 2. The present invention adopts blue light chip and secondary light emitting conversion material to realize single substrate and monolithic integration of Mirco LED display array chip, thereby reducing the difficulty of processing red, green and blue (RGB) color chips and the difficulty of integrated processing.

[0010] 3. The present invention adopts a common N-pole highly doped GaN layer to connect the N-type GaN conductive layer of the entire row of chips, that is, the chips in the entire row share a common N electrode point. This method reduces the difficulty of chip processing in terms of technology. At the same time, because highly doped GaN is used as the common N-pole material, the line loss problem of the chip far away from the electrode point can be alleviated. Summary of the invention

[0011] The present invention aims to solve the technical problems existing in the known technologies and provides a GaN-based flip-chip common N-pole full-color micro display array and a manufacturing method thereof.

[0012] The first object of the present invention is to provide a GaN-based flip-chip common N-pole full-color micro display array, comprising a MicroLED array chip and a supporting circuit board, wherein:

[0013] The Micro LED array chip comprises a substrate (1), a buffer layer (2) located on one side of the upper surface of the substrate (1), a common N-pole highly doped GaN layer (3) located on the upper surface of the buffer layer (2) and formed by row etching, an N-type GaN conductive layer (4) located on the upper surface of the common N-pole highly doped GaN layer (3) and formed by growth and etching according to the size and position of each chip, a GaN / InGaN multi-quantum well active region (5) located on the upper surface of the N-type GaN conductive layer (4) and formed by growth and etching, a P-type GaN conductive layer (6) located on the upper surface of the GaN / InGaN multi-quantum well active region (5) and formed by growth and etching, a P-electrode point (7) located on the P-type GaN conductive layer (6), and an N-electrode point (8) located above the common N-pole highly doped GaN layer (3) and at both ends of the array chip; a (RGB) red, green, and blue secondary light-emitting material layer (10) is filled on one side of the lower surface of the substrate (1) by trenching;

[0014] The supporting circuit board comprises a substrate (2-1), on which an N-pole circuit (2-2) and a P-pole circuit (2-3) which do not overlap are etched, and external pins are led out from the N-pole circuit (2-2) and the P-pole circuit (2-3);

[0015] The P electrode point (7), the N electrode point (8) of the Micro LED array chip and the P pole line (2-3) and the N pole line (2-2) of the supporting circuit board are connected by flip-chip bonding.

[0016] Preferably, the substrate layer (1), the buffer layer (2), the N-type highly doped GaN layer (3), the N-type GaN conductive layer (4), the GaN / InGaN multi-quantum well active region (5) and the P-type GaN conductive layer (6) constitute an epitaxial material structure of a Micro LED array chip.

[0017] Preferably, a device structure of a Micro LED array chip is formed by a micro-sized LED array isolated from each other by an insulating layer (9), each Micro LED in the array constitutes a separate light-emitting point, each chip of the Micro LED array chip has a separate P electrode point (7), each row of chips of the Micro LED array chip is interconnected through a common N-pole highly doped GaN layer (3), and each row shares a common N electrode point (8).

[0018] Preferably, each Micro LED in the array of the Micro LED array chip is a light-emitting point, and the original Micro LED emits blue light when in operation. Three adjacent Micro LEDs in each row of the array form a display pixel point, wherein one Micro LED corresponds to the position of the red light-emitting material in the secondary light-emitting material layer (10) on the lower surface of the substrate (1), and another Micro LED corresponds to the position of the green light-emitting material in the secondary light-emitting material layer (10) on the lower surface of the substrate (1). The three Micro LEDs together form a red, green and blue pixel point through the substrate.

[0019] Preferably, the N-pole circuit (2-2) and the P-pole circuit (2-3) are insulated from each other, the P-electrode column circuits are conductive, and each column shares a P-electrode circuit.

[0020] Preferably, after the Micro LED array chip and the supporting circuit board are bonded and connected, the Micro LED array chip is powered by the supporting circuit board, each row of the Micro LED array chip shares an N-pole circuit (2-2), and each column shares a P-pole circuit (2-3), and the Micro LED at a position selected by the intersection of the row and column electrode circuits in the array is powered externally by the pins of the P-pole circuit (2-3) and the N-pole circuit (2-2) to emit light.

[0021] Preferably, the N-pole circuit is a row electrode, and the P-pole circuit is a column electrode.

[0022] Preferably, the P-pole circuit is a row electrode, and the N-pole circuit is a column electrode.

[0023] The second object of the present invention is to provide a method for manufacturing a GaN-based flip-chip common N-pole full-color micro display array, comprising:

[0024] S1. Manufacturing the Micro LED array chip according to claim 1;

[0025] S2. Manufacturing the supporting circuit board according to claim 1;

[0026] S3. Use flip-chip bonding to connect the Micro LED array chip to the supporting circuit board.

[0027] Preferably, the process of manufacturing the Micro LED array chip includes:

[0028] S101, growing a buffer layer (2) on one side of the upper surface of the substrate (1);

[0029] S102, growing a common N-pole highly doped GaN layer (3) on the upper surface of the buffer layer (2);

[0030] S103, growing an N-type GaN conductive layer (4) on the common N-pole highly doped GaN layer (3);

[0031] S104, growing a GaN / InGaN multi-quantum well active region (5) on the N-type GaN conductive layer (4);

[0032] S105, growing a P-type GaN conductive layer (6) on the upper surface of the GaN / InGaN multi-quantum well active region (5);

[0033] S106, after photolithography defines the Micro LED array area, etching the epitaxial chip to the N-pole highly doped GaN layer (3) to form a Micro LED array;

[0034] S107, photolithography defines the secondary light-emitting material layer region on the lower surface of the substrate (1) corresponding to the Micro LED array region, and dry-etches to form a filling groove for the secondary light-emitting material layer (10);

[0035] S108, photolithography is used to define the Micro LED array P electrode region, and a Micro LED metal P electrode is manufactured (7);

[0036] S109, photolithography is used to define the Micro LED array N electrode region, and a Micro LED metal N electrode is manufactured (8);

[0037] S110, filling an insulating layer (9) on the surface of the Micro LED array;

[0038] S111, filling the grooves on the lower surface of the substrate (1) with (RGB) red, green and blue secondary light-emitting materials;

[0039] S112, depositing a dielectric protective layer on the lower surface of the substrate (1);

[0040] S113, Micro LED array chip unit dicing and splitting, completing the Micro LED array chip production.

[0041] Preferably, the process of making the supporting circuit board includes:

[0042] S201, making a metal adhesion layer and a metal connection layer on the surface of the substrate (2-1) to form a metal layer supporting the circuit board;

[0043] S202, photolithography of N-pole circuit (2-2) and P-pole circuit (2-3) patterns on the surface of the metal layer, wherein the electrode patterns are designed to have sizes and positions corresponding to the N-electrode point (8) and the P-electrode point (7) in the Micro LED array chip;

[0044] S203, obtaining an N-pole circuit (2-2) and a P-pole circuit (2-3) by dry etching or wet etching;

[0045] The process of connecting the Micro LED array chip and the supporting circuit board by flip-chip bonding is as follows:

[0046] S301, place the upper surface of the Micro LED array chip downward, and align its N electrode point (8) and P electrode point (7) with the N pole line (2-2) and P pole line (2-3) of the supporting circuit board;

[0047] S302, heating and applying pressure to the Micro LED array chip and the supporting circuit board to complete the welding interconnection between the P electrode and the N electrode of the Micro LED array chip and the N-pole line (2-2) and the P-pole line (2-3) of the supporting circuit board;

[0048] S303, the supporting circuit board supplies power and controls the Micro LED array chip through external pins.

[0049] The advantages and positive effects of the present invention are:

[0050] In terms of chip structure design, the present invention uses a common N-pole structure to avoid etching the N-electrode on the surface of the Micro LED chip, saving nearly 25% of the chip electrode area and improving the utilization rate of LED materials; it avoids the occupation of the metal common N-pole on the MicroLED chip array area, improves the resolution, and has a higher screen utilization rate than other light-emitting unit array arrangement structures; using highly doped N-type material as the common N-pole effectively alleviates the problem of current attenuation away from the electrode point; the design of the supporting circuit is optimized in the passive addressing lighting method, and under the drive of the matching driving circuit, the columns can be selected simultaneously, thereby improving the refresh speed of the array display; the flip-chip bonding welding method avoids the substrate stripping process in other structural process flows, and also avoids the process complexity and reduced yield problems caused by the massive transfer of Micro LEDs in subsequent processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a cross-sectional view of a Micro LED array chip according to an embodiment of the present invention;

[0052] Figure 2 1 is a top view of a Micro LED array chip according to an embodiment of the present invention;

[0053] Figure 3 is a top view of a supporting circuit board in an embodiment of the present invention;

[0054] Figure 4 The process flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0055] In order to further understand the content, features and effects of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings:

[0056] The technical solution of the present invention is:

[0057] See also Figures 1 to 4 , to facilitate the description of the document, the attached figure takes a 3-row 9-column array structure as an example for explanation. In actual application, the number of Micro LEDs in the array can be infinitely expanded.

[0058] A GaN-based flip-chip common N-pole full-color micro display array includes a Micro LED array chip and a supporting circuit board, wherein:

[0059] The Micro LED array chip includes a substrate 1, a buffer layer 2 located on one side of the upper surface of the substrate 1, a common N-pole highly doped GaN layer 3 located on the upper surface of the buffer layer 2 and formed by row etching, an N-type GaN conductive layer 4 located on the upper surface of the common N-pole highly doped GaN layer 3 and formed by growth and etching according to the size and position of each chip, a GaN / InGaN multi-quantum well active region 5 grown and etched on the upper surface of the N-type GaN conductive layer 4, a P-type GaN conductive layer 6 located on the upper surface of the GaN / InGaN multi-quantum well active region 5 and formed by growth and etching, a P-electrode point 7 located on the P-type GaN conductive layer 6, and an N-electrode point 8 located above the common N-pole highly doped GaN layer 3 and at both ends of the array chip; an RGB red, green, and blue secondary light-emitting material layer 10 is filled on one side of the lower surface of the substrate 1 by trenching;

[0060] The supporting circuit board includes a substrate 2-1, on which an N-pole line 2-2 and a P-pole line 2-3 are etched so as to not overlap each other, and the N-pole line 2-2 and the P-pole line 2-3 are connected to external pins;

[0061] The P electrode point 7, the N electrode point 8 of the Micro LED array chip and the P pole line 2-3 and the N pole line 2-2 of the supporting circuit board are connected by flip-chip bonding.

[0062] The Micro LED array chip in this application is composed of a common N-pole Micro LED row chip array, and the supporting circuit board is connected by a common P-pole line. After the Micro LED array chip and the supporting circuit board are flip-chip soldered, the pixels in the Micro LED array chip can work through row and column gating. The present invention uses a common N electrode at the bottom of the Micro LED in the chip structure design, which can reduce the chip electrode area loss by nearly 25% and improve material utilization; avoids the occupation of the metal common N pole on the Micro LED chip array area, improves the resolution, and has a higher screen utilization rate than other light-emitting unit array arrangement structures; uses highly doped N-type materials as the common N pole, which alleviates the problem of light attenuation caused by line loss of Micro LED; the flip-chip bonding welding method of the Micro LED array chip and the supporting circuit board avoids the substrate peeling process in other structural process flows, and also avoids the yield reduction problem caused by the mass transfer of Micro LED.

[0063] The substrate layer 1, the buffer layer 2, the N-type highly doped GaN layer 3, the N-type GaN conductive layer 4, the GaN / InGaN multi-quantum well active region 5 and the P-type GaN conductive layer 6 constitute the epitaxial material structure of the Micro LED array chip.

[0064] The device structure of the Micro LED array chip is composed of a micro-sized LED array isolated from each other by an insulating layer 9. Each Micro LED in the array constitutes a separate light-emitting point. Each chip of the Micro LED array chip has a separate P electrode point 7. Each row of chips in the Micro LED array chip is interconnected through a common N-pole highly doped GaN layer 3, and each row shares a common N electrode point 8.

[0065] Each Micro LED in the array of the Micro LED array chip is a light-emitting point. The original Micro LED emits blue light when working. Three adjacent Micro LEDs in each row of the array form a display pixel point. One Micro LED corresponds to the position of the red light-emitting material in the secondary light-emitting material layer 10 on the lower surface of the substrate 1, and the other Micro LED corresponds to the position of the green light-emitting material in the secondary light-emitting material layer 10 on the lower surface of the substrate 1. The three Micro LEDs together form a red, green and blue pixel point through the substrate.

[0066] The N-pole line 2 - 2 and the P-pole line 2 - 3 are insulated from each other, the P-electrode column lines are conductive, and each column shares a P-electrode line.

[0067] After the Micro LED array chip and the supporting circuit board are bonded and connected, the Micro LED array chip is powered by the supporting circuit board. Each row of the Micro LED array chip shares the N-pole line 2-2, and each column shares the P-pole line 2-3. The Micro LEDs at the selected positions where the row and column electrode lines in the array intersect are powered and illuminated by the pins of the P-pole line 2-3 and the N-pole line 2-2.

[0068] The N-pole circuit is a row electrode, and the P-pole circuit is a column electrode.

[0069] The P-pole circuit is a row electrode, and the N-pole circuit is a column electrode.

[0070] The epitaxial material structure of the Micro LED array chip is

[0071] (1) Including but not limited to sapphire or silicon carbide substrates.

[0072] (2) GaN buffer layer, buffer layer thickness 5 μm.

[0073] (3) N-type highly doped GaN layer, thickness 3μm, N-type doping concentration 10 19 / cm 3 ;

[0074] (4) N-type GaN conductive layer, thickness 1 μm, N-type doping concentration 10 18 / cm 3 ;

[0075] (5)GaN / InGaN multi-quantum well active region, multi-quantum well period 10, multi-quantum well composition GaN / In 0.25 Ga 0 / 75 N, multi-quantum well GaN thickness 7nm, InGaN thickness 3nm;

[0076] (6) P-type GaN conductive layer, thickness 1.5 μm, including 1 μm of P-type doping concentration 5×10 17 / cm 3 The electrode layer and 0.5 μm 1×10 18 / cm 3 Ohmic contact layer.

[0077] The device structure of the Micro LED array chip is as follows:

[0078] (1) Each chip in the Micro LED array has a separate P electrode point. The P electrode point is made of high-reflectivity metal Cr / Al / Ti / Au with an overall thickness of 2μm;

[0079] (2) Each row of Micro LED array chips is interconnected through a common N-pole highly doped GaN layer (3). Each row shares a common N electrode point, which is made of metal Ti / Au. To facilitate the subsequent welding process, the thickness of the N electrode metal is adjusted so that the surface height is consistent with the P electrode surface.

[0080] (3) Chip insulation layer. The insulation layer uses SiO2 or SiN x The insulating layer isolates the Micro LEDs in the array from each other, and each Micro LED in the array constitutes a separate light-emitting point.

[0081] The red, green and blue three-color conversion structure of the Micro LED array chip is:

[0082] Each Micro LED in the array is a light-emitting point, and the original Micro LED emits blue light when working;

[0083] Three adjacent Micro LEDs in each row of the array form a display pixel;

[0084] One of the Micro LEDs corresponds to the position of the red light emitting material in the secondary light emitting material layer (10) on the lower surface of the substrate (1);

[0085] Another Micro LED corresponds to the position of the green light emitting material in the secondary light emitting material layer (10) on the lower surface of the substrate (1);

[0086] The secondary light-emitting material layer may be, but is not limited to, phosphor material, quantum dot material, etc.

[0087] Three adjacent Micro LEDs form a red, green and blue pixel through the substrate.

[0088] The formed Micro LED array is only an example provided to illustrate the present invention. In fact, the Micro LED array can be distributed in any chip shape and any arrangement.

[0089] In the supporting circuit board structure:

[0090] Substrate 2-1, the substrate material of the present invention may include but is not limited to Si substrate, glass substrate or other insulating materials, and its electrode line material may be made of but not limited to metals such as Ni / Au, and is prepared by electroplating, deposition, photolithography, etching and other processes.

[0091] The N-pole line 2-2 is made of metal Ti / Au, with an overall thickness of 3μm and a welding pin extending outward;

[0092] The P-pole line 2-3 is made of metal Ti / Au, with an overall thickness of 3μm, and has welding pins extending outward;

[0093] The N-pole line and the P-pole line are insulated from each other.

[0094] The P-electrode column lines are turned on, and each column shares one P-electrode line.

[0095] The Micro LED array chip and supporting circuit board:

[0096] The size and position of the P electrode point 7 and the N electrode point 8 of the Micro LED array chip correspond to the P pole line 2-3 and the N pole line 2-2 of the supporting circuit board respectively;

[0097] The P electrode point 7 and the N electrode point 8 of the Micro LED array chip and the P-pole line 2-3 and the N-pole line 2-2 of the supporting circuit board are connected by flip-chip bonding;

[0098] After the Micro LED array chip and the supporting circuit board are bonded to each other, the Micro LED array chip can be powered by the supporting circuit board;

[0099] Each row of Micro LED array chips shares the N-electrode line 2-2, and each column shares the P-electrode line 2-3;

[0100] The Micro LED at the position selected by the intersection of the row and column electrode lines in the array is powered by the external pins of the P-pole line 2-3 and the N-pole line 2-2 to emit light.

[0101] A method for manufacturing a GaN-based flip-chip common N-pole full-color micro display array, comprising:

[0102] S1. Making Micro LED array chips:

[0103] S101, growing a 5 μm GaN buffer layer 2 on one side of the upper surface of the substrate 1;

[0104] S102, grow a common N-pole highly doped GaN layer 3 on the upper surface of the buffer layer 2, with a growth thickness of 3 μm and an N-type doping concentration of 10 19 / cm 3 ;

[0105] S103, growing an N-type GaN conductive layer 4 on the common N-pole highly doped GaN layer 3, with a thickness of 1 μm and an N-type doping concentration of 10 18 / cm 3 ;

[0106] S104, growing GaN / InGaN multi-quantum well active region 5 on N-type GaN conductive layer 4, multi-quantum well period 10, multi-quantum well composition GaN / In 0.25 Ga 0 / 75 N, multi-quantum well GaN thickness 7nm, InGaN thickness 3nm;

[0107] S105, growing a P-type GaN conductive layer 6 on the upper surface of the GaN / InGaN multi-quantum well active region 5, with a thickness of 1.5 μm, including 1 μm of P-type doping concentration of 5×10 17 / cm 3 The electrode layer and 0.5 μm 1×10 18 / cm 3 Ohmic contact layer;

[0108] S106, after the Micro LED array area is defined by photolithography, the epitaxial chip is etched to a depth of the N-pole highly doped GaN layer 3 to form a Micro LED array;

[0109] S107, photolithography defines the secondary light-emitting material layer area on the lower surface of the substrate 2 corresponding to the Micro LED array area, and dry-etches to form a filling groove for the secondary light-emitting material layer 10, the size of the filling groove is consistent with the size of the Micro LED, and the etching depth is 5 microns;

[0110] S108, photolithography defines the Micro LED array P electrode area, and manufactures the Micro LED metal P electrode 7. The P electrode point is made of high-reflectivity metal Cr / Al / Ti / Au, with an overall thickness of 2 μm;

[0111] S109, photolithography defines the Micro LED array N electrode area, and manufactures the Micro LED metal N electrode 8. Each row of the Micro LED array chip is interconnected through a common N-pole highly doped GaN layer 3, and each row shares a common N electrode point, which is made of metal Ti / Au. To facilitate the subsequent welding process, the N electrode metal thickness is adjusted, and the surface height is consistent with the P electrode surface.

[0112] S110, the surface of Micro LED array is filled with an insulating layer 9, the insulating layer is made of SiO2 or SiN x The filling height is consistent with that of MicroLED. The insulating layer isolates the MicroLEDs in the array from each other, and each MicroLED in the array constitutes a separate light-emitting point;

[0113] S111, the grooves on the lower surface of the Micro LED array substrate 1 are filled with (RGB) red, green and blue secondary light-emitting materials, and the corresponding spectra of the filled secondary light-emitting materials are red light, green light and blue light (or there is no light conversion material, so that the Micro LED spectrum is directly transmitted);

[0114] S112, SiO2 or SiN is deposited on the lower surface of the Micro LED array substrate 1 x Dielectric protection layer, thickness 2μm;

[0115] S113, Micro LED array chip unit dicing and splitting, completing the Micro LED array chip production.

[0116] S2. Process of making Micro LED support circuit board:

[0117] S201, making a metal adhesion layer and a metal connection layer on the surface of the substrate 2-1 to form a metal layer of the supporting circuit board, using metal Ti / Au with an overall thickness of 3 μm;

[0118] S202, making a SiNx passivation film on the surface of the metal layer, photolithography of the N-pole line 2-2 and the P-pole line 2-3 patterns on the passivation film, and etching of the P and N electrode line patterns. The design size and position correspond to the N electrode point 8 and the P electrode point 7 in the Micro LED array chip respectively.

[0119] S203, using the SiNx passivation film as a mask, dry etching or wet etching is performed to obtain an N-pole line 2-2 and a P-pole line 2-3.

[0120] S3. The process of connecting the Micro LED array chip and the supporting circuit board by flip-chip bonding:

[0121] S301, place the upper surface of the Micro LED array chip downward, and align its N electrode point 8 and P electrode point 7 with the N-pole line 2-2 and P-pole line 2-3 of the supporting circuit board.

[0122] S302, heating and applying pressure to the Micro LED array chip and the supporting circuit board to complete the welding interconnection between the P electrode and N electrode of the Micro LED array chip and the N-pole line 2-2 and the P-pole line 2-3 of the supporting circuit board.

[0123] S303, the supporting circuit board supplies power and controls the Micro LED array chip through external pins.

[0124] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are within the scope of the technical solution of the present invention.

Claims

1. A GaN-based flip-chip common N-pole full-color micro display array, characterized in that: It includes Micro LED array chip and supporting circuit board, wherein: The Micro LED array chip includes a substrate, a buffer layer located on one side of the upper surface of the substrate, a common N-pole highly doped GaN layer located on the upper surface of the buffer layer and formed by row etching, an N-type GaN conductive layer located on the upper surface of the common N-pole highly doped GaN layer and formed by growth and etching according to the size and position of each chip, a GaN / InGaN multi-quantum well active region grown and etched on the upper surface of the N-type GaN conductive layer, a P-type GaN conductive layer located on the upper surface of the GaN / InGaN multi-quantum well active region and formed by growth and etching, a P-electrode point located on the P-type GaN conductive layer, and an N-electrode point located above the common N-pole highly doped GaN layer and at both ends of the array chip; a red, green, and blue secondary light-emitting material layer is filled on one side of the lower surface of the substrate by trenching; The supporting circuit board includes a substrate, on which an N-pole circuit and a P-pole circuit that do not overlap are etched, and the N-pole circuit and the P-pole circuit lead to external pins; The P electrode points and N electrode points of the Micro LED array chip and the P-pole circuit and N-pole circuit of the supporting circuit board are connected by flip-chip bonding. The N-pole circuit and the P-pole circuit are insulated from each other, the P-electrode column circuit is conductive, and each column shares a P-electrode circuit; After the Micro LED array chip and the supporting circuit board are bonded and connected, the Micro LED array chip is powered by the supporting circuit board. Each row of the Micro LED array chip shares the N-pole circuit, and each column shares the P-pole circuit. The Micro LEDs at the selected positions where the row and column electrode circuits in the array intersect are powered and illuminated by the external pins of the P-pole circuit and the N-pole circuit.

2. The GaN-based flip-chip common N-pole full-color micro display array according to claim 1, characterized in that: The substrate layer, buffer layer, N-highly doped GaN layer, N-type GaN conductive layer, GaN / InGaN multi-quantum well active region and P-type GaN conductive layer constitute the epitaxial material structure of the Micro LED array chip.

3. The GaN-based flip-chip common N-pole full-color micro display array according to claim 1, characterized in that: The device structure of the Micro LED array chip consists of micro-sized LED arrays isolated from each other by an insulating layer. Each Micro LED in the array constitutes a separate light-emitting point. Each chip of the Micro LED array chip has a separate P electrode point. Each row of chips in the Micro LED array chip is interconnected through a common N-pole highly doped GaN layer, and each row shares a common N electrode point.

4. The GaN-based flip-chip common N-pole full-color micro display array according to any one of claims 1 to 3, characterized in that: Each Micro LED in the array of the Micro LED array chip is a light-emitting point. The original Micro LED emits blue light when working. Three adjacent Micro LEDs in each row of the array form a display pixel. One Micro LED corresponds to the position of the red light-emitting material in the secondary light-emitting material layer on the lower surface of the substrate, and the other Micro LED corresponds to the position of the green light-emitting material in the secondary light-emitting material layer on the lower surface of the substrate. The three Micro LEDs together form a red, green and blue pixel through the substrate.

5. The GaN-based flip-chip common N-pole full-color micro display array according to claim 1, characterized in that: The N-pole circuit is a row electrode, and the P-pole circuit is a column electrode; or, the P-pole circuit is a row electrode, and the N-pole circuit is a column electrode.

6. A method for manufacturing a GaN-based flip-chip common N-pole full-color micro display array, characterized in that: include: S1. Manufacturing the Micro LED array chip according to claim 1; S2. Manufacturing the supporting circuit board according to claim 1; S3. Use flip-chip bonding to connect the Micro LED array chip to the supporting circuit board.

7. The method for manufacturing a GaN-based flip-chip common N-pole full-color micro display array according to claim 6, characterized in that: The process of making Micro LED array chips includes: S101, growing a buffer layer on one side of the upper surface of the substrate; S102, growing a common N-pole highly doped GaN layer on the upper surface of the buffer layer; S103, growing an N-type GaN conductive layer on the common N-pole highly doped GaN layer; S104, growing a GaN / InGaN multi-quantum well active region on the N-type GaN conductive layer; S105, growing a P-type GaN conductive layer on the upper surface of the GaN / InGaN multi-quantum well active region; S106, after the Micro LED array area is defined by photolithography, the epitaxial chip is etched to the N-pole highly doped GaN layer to form a Micro LED array; S107, photolithography defines the secondary light-emitting material layer area on the lower surface of the substrate corresponding to the Micro LED array area, and dry-etches to form a filling groove for the secondary light-emitting material layer; S108, photolithography defines the Micro LED array P electrode area, and manufactures the Micro LED metal P electrode; S109, photolithography defines the Micro LED array N electrode area, and manufactures the Micro LED metal N electrode; S110, the surface of Micro LED array is filled with an insulating layer; S111, filling the groove on the lower surface of the substrate with red, green and blue secondary light-emitting materials; S112, depositing a dielectric protection layer on the lower surface of the substrate; S113, Micro LED array chip unit dicing and splitting, completing the Micro LED array chip production.

8. The method for manufacturing a GaN-based flip-chip common N-pole full-color micro display array according to claim 6, characterized in that: The process of making a support circuit board includes: S201, manufacturing a metal adhesion layer and a metal connection layer on the surface of the substrate to form a metal layer supporting the circuit board; S202, photolithography of N-pole circuits and P-pole circuits on the surface of the metal layer, wherein the electrode pattern design size and position correspond to the N-electrode point and the P-electrode point in the Micro LED array chip respectively; S203, obtaining an N-pole circuit and a P-pole circuit by dry etching or wet etching; The process of connecting the Micro LED array chip and the supporting circuit board by flip-chip bonding is as follows: S301, placing the upper surface of the Micro LED array chip downward, and aligning its N electrode point and P electrode point with the N pole line and P pole line of the supporting circuit board; S302, heating and applying pressure to the Micro LED array chip and the supporting circuit board to complete the welding interconnection between the P electrode and N electrode of the Micro LED array chip and the N pole line and P pole line of the supporting circuit board; S303, the supporting circuit board supplies power and controls the Micro LED array chip through external pins.

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