LED chip, LED display device and LED chip processing method

Abstract

The present invention provides an LED chip, an LED display device and a processing method of an LED chip, wherein the LED chip comprises: an epitaxial layer, the top surface of the epitaxial layer forms a light-emitting surface; a first electrode and a second electrode, the first electrode and the second electrode are arranged at intervals on the bottom surface of the epitaxial layer, and the first electrode and the second electrode are both conductively connected to the epitaxial layer; a reflective layer, which is coated on the side and bottom surfaces of the epitaxial layer and avoids the first electrode and the second electrode; and a quantum layer, which is arranged on the light-emitting surface of the epitaxial layer. The technical solution of the present application effectively solves the problem in the related art that blue light leaks when blue light LED excites quantum dots, resulting in poor color conversion effect.

Description

Technical Field

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

[0002] In the LED chip industry, Al2O3 (aluminum oxide) is usually used as the substrate for blue and green LEDs, and an epitaxial GaN (gallium nitride) light-emitting layer is set on the LED substrate. GaAs (gallium arsenide) is used as the substrate for red LEDs, and an epitaxial AlGaInP (gallium arsenide phosphide) light-emitting layer is set on the substrate of the red LED. When preparing flip chips, because Al2O3 is transparent, in theory, it is only necessary to simply invert the LED chip and then use the reflector process to achieve blue-green light flip chips. For red chips, because their substrate GaAs absorbs red light, flip chips cannot be achieved by simple inversion. The red light epitaxial layer needs to be transferred to a transparent substrate, and then the GaAs substrate is peeled off to obtain a flip-chip red light chip. Compared with GaN (gallium nitride) materials, the red light AlGaInP epitaxial layer is brittle and fragile, so the above process results in low yield and high cost of flip-chip red LEDs.

[0003] Quantum dots, as a nano-luminescent material, can be used in LED color conversion. Blue LEDs or purple LEDs excite quantum dots to emit corresponding colors. Because purple LEDs are expensive, inkjet printing is usually used to set quantum dot materials on blue LED chips. However, this method causes blue light leakage, which causes blue light to be mixed with the excited color light, resulting in poor color conversion effect. Summary of the invention

[0004] The main purpose of the present invention is to provide an LED chip, an LED display device and a method for processing an LED chip to solve the problem in the related art that blue light leaks when blue light LED excites quantum dots, resulting in poor color conversion effect.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided an LED chip, comprising: an epitaxial layer, the top surface of the epitaxial layer forming a light emitting surface; a first electrode and a second electrode, the first electrode and the second electrode being arranged at intervals on the bottom surface of the epitaxial layer, and the first electrode and the second electrode being conductively connected to the epitaxial layer; a reflective layer, covering the side surface and the bottom surface of the epitaxial layer and avoiding the first electrode and the second electrode; and a quantum layer, arranged on the light emitting surface of the epitaxial layer.

[0006] Furthermore, the LED chip also includes a light absorbing layer arranged outside the side wall of the reflective layer.

[0007] Furthermore, the outer side surface of the quantum layer is flush with or protrudes from the outer side surface of the light absorbing layer.

[0008] Furthermore, the reflective layer includes an internal reflective layer coated on the side and bottom surfaces of the epitaxial layer and an external reflective layer coated on the outside of the internal reflective layer. The internal reflective layer is a Bragg reflector and the external reflective layer is ink.

[0009] Furthermore, the LED chip also includes a transparent protective layer covering the outer sides of the quantum layer and the light absorbing layer.

[0010] Furthermore, the epitaxial layer includes a first gallium nitride layer, a quantum well and a second gallium nitride layer arranged in sequence from the top surface to the bottom surface, a first mounting hole is arranged on the second gallium nitride layer, a second mounting hole corresponding to the first mounting hole is arranged on the quantum well, the first electrode is conductively connected to the second gallium nitride layer, and part of the second electrode is penetrated into the first mounting hole and the second mounting hole and conductively connected to the first gallium nitride layer; the LED chip also includes an insulating layer, the insulating layer includes a first insulating portion arranged between the bottom surface of the epitaxial layer and the reflective layer and a second insulating portion arranged between the epitaxial layer and the second electrode; the LED chip also includes a guide layer located between the first electrode and the second gallium nitride layer; the guide layer is located on the side of the second insulating portion.

[0011] According to another aspect of the present invention, there is provided an LED display device, comprising a substrate and a plurality of display units fixed to the substrate, each display unit comprising a plurality of LED chips, and the LED chips are the above-mentioned LED chips.

[0012] According to another aspect of the present invention, a method for processing an LED chip is provided, which is used to process the above-mentioned LED chip, and the processing method comprises the following steps: arranging an epitaxial layer on a substrate, and obtaining a first electrode and a second electrode connected to the epitaxial layer; coating a reflective layer on the side and bottom surfaces of the epitaxial layer and avoiding the first electrode and the second electrode; removing the substrate; after removing the substrate, forming a quantum layer on the light emitting surface of the epitaxial layer.

[0013] Furthermore, between the step of coating the reflective layer on the side and bottom of the epitaxial layer and avoiding the first electrode and the second electrode and the step of removing the substrate, the processing method further includes: forming a light absorbing layer outside the side of the reflective layer.

[0014] Furthermore, after removing the substrate, the step of forming a quantum layer on the light-emitting surface of the epitaxial layer includes: after removing the substrate, placing the first electrode and the second electrode downward on the temporary substrate to form a quantum layer on the light-emitting surface of the epitaxial layer.

[0015] Furthermore, after the step of forming a quantum layer on the light-emitting surface of the epitaxial layer, the processing method further comprises: coating the outer sides of the quantum layer and the light-absorbing layer with a transparent protective layer.

[0016] Applying the technical solution of the present invention, the LED chip includes: an epitaxial layer, a first electrode, a second electrode reflective layer and a quantum layer. The top surface of the epitaxial layer forms a light-emitting surface. The first electrode and the second electrode are arranged at intervals on the bottom surface of the epitaxial layer, and the first electrode and the second electrode are both conductively connected to the epitaxial layer. The reflective layer is coated on the side and bottom surfaces of the epitaxial layer, and avoids the first electrode and the second electrode. The quantum layer is arranged on the light-emitting surface of the epitaxial layer. After the first electrode and the second electrode are energized, the epitaxial layer emits blue light. Since the reflective layer is coated on the side and bottom surfaces of the epitaxial layer, the reflective layer reflects the blue light emitted by the epitaxial layer, so that the blue light emitted by the epitaxial layer is concentrated and emitted from the light-emitting surface, effectively reducing the leakage of blue light, so that more blue light passes through the quantum layer for color conversion, and improves the color conversion effect. Therefore, the technical solution of the present application can solve the problem of blue light leakage when the blue light LED excites quantum dots in the related art, resulting in poor color conversion effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 A cross-sectional schematic diagram of an embodiment of an LED chip according to the present invention is shown;

[0019] Figure 2 A schematic diagram showing a process flow of an embodiment of a method for processing an LED chip according to the present invention is shown;

[0020] Figure 3 Shows Figure 2 A cross-sectional schematic diagram of an LED chip processing method in which an epitaxial layer is placed on a substrate;

[0021] Figure 4 Shows Figure 2 A cross-sectional schematic diagram of a method for processing an LED chip, wherein a mounting hole is processed on an epitaxial layer;

[0022] Figure 5 Shows Figure 2 A cross-sectional schematic diagram of a method for processing an LED chip in which a guide layer is covered on the second gallium nitride;

[0023] Figure 6 Shows Figure 2 A cross-sectional schematic diagram of a method for processing an LED chip, wherein a first electrode is disposed on a guide layer;

[0024] Figure 7 Shows Figure 2 A cross-sectional schematic diagram of a method for processing an LED chip, wherein an insulating layer is provided on a guide layer and a side wall of a mounting hole;

[0025] Figure 8 Shows Figure 2 A cross-sectional schematic diagram of a method for processing an LED chip in which a portion of the second electrode is installed in a mounting hole;

[0026] Fig. 9 Shows Figure 2 A cross-sectional schematic diagram of a method for processing an LED chip, wherein a portion of the first gallium nitride protruding outside the second gallium nitride is removed;

[0027] Fig.10 Shows Figure 2 A cross-sectional schematic diagram of a method for processing an LED chip in which an internal reflection layer is coated outside an epitaxial layer;

[0028] Fig.11 Shows Figure 2 A cross-sectional schematic diagram of a method for processing an LED chip in which an outer reflective layer is coated outside an inner reflective layer;

[0029] Fig.12 Shows Figure 2 A cross-sectional schematic diagram of forming a light absorbing layer on the outer side wall of an outer reflective layer in a method for processing an LED chip;

[0030] Fig.13 Shows Figure 2 A cross-sectional schematic diagram of an LED chip processing method in which, after removing the substrate, the epitaxial layer is inverted on a temporary substrate;

[0031] Fig.14 Shows Figure 2 A schematic cross-sectional view of forming a quantum layer on the second gallium nitride of the epitaxial layer in a method for processing an LED chip;

[0032] Fig.15 Shows Figure 2 A schematic cross-sectional view of a method for processing an LED chip in which an epitaxial layer is divided into three parts;

[0033] Fig.16 Shows Figure 2 A cross-sectional schematic diagram of an LED chip processing method in which a transparent protective layer is coated on the outside of a quantum layer and a light absorbing layer.

[0034] The above drawings include the following reference numerals:

[0035] 1. Substrate; 2. Temporary substrate; 10. Epitaxial layer; 101. Light emitting surface; 11. Mounting hole; 111. First mounting hole; 112. Second mounting hole; 12. First gallium nitride layer; 13. Quantum well; 14. Second gallium nitride layer; 21. First electrode; 22. Second electrode; 30. Insulating layer; 40. Reflective layer; 41. Internal reflection layer; 42. External reflection layer; 50. Quantum layer; 51. External side surface of quantum layer; 60. Light absorbing layer; 61. External side surface of light absorbing layer; 70. Transparent protective layer; 80. Guide layer. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0038] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0039] like Figure 1As shown, the LED chip of this embodiment includes: an epitaxial layer 10, a first electrode 21, a second electrode 22, a reflective layer 40 and a quantum layer 50. The top surface of the epitaxial layer 10 forms a light-emitting surface 101. The first electrode 21 and the second electrode 22 are arranged at intervals on the bottom surface of the epitaxial layer 10, and the first electrode 21 and the second electrode 22 are both conductively connected to the epitaxial layer 10. The reflective layer 40 is coated on the side and bottom surface of the epitaxial layer 10, and avoids the first electrode 21 and the second electrode 22. The quantum layer 50 is arranged at the light-emitting surface 101 of the epitaxial layer 10.

[0040] Applying the technical solution of this embodiment, the LED chip includes: the reflective layer 40 is coated on the side and bottom of the epitaxial layer 10, and avoids the first electrode 21 and the second electrode 22. The quantum layer 50 is arranged at the light-emitting surface 101 of the epitaxial layer 10. After the first electrode 21 and the second electrode 22 are energized, the epitaxial layer 10 emits blue light. Since the reflective layer 40 is coated on the side and bottom of the epitaxial layer 10, the reflective layer 40 reflects the blue light emitted by the epitaxial layer 10, so that the blue light emitted by the epitaxial layer 10 is concentrated and emitted from the light-emitting surface 101, effectively reducing the leakage of blue light, so that more blue light passes through the quantum layer 50 for color conversion, and improves the color conversion effect. Therefore, the technical solution of this embodiment can solve the problem of blue light leakage when the blue light LED excites the quantum dots in the related art, resulting in poor color conversion effect. The way in which the blue light emitted by the epitaxial layer 10 is superimposed on the quantum layer 50 for color conversion can realize LEDs of other colors, which can effectively reduce the cost of red light LED chips.

[0041] It should be noted that the top surface of the above-mentioned epitaxial layer 10 is the light-emitting surface. In actual use, when the light-emitting surface extends in the vertical direction, the top surface is the front surface and the bottom surface is the back surface. The above-mentioned quantum layer 50 is preferably a quantum dot film, or a mixture of quantum dots and glue. The quantum layer 50 is used to convert the blue light emitted by the epitaxial layer into light of other colors. For example, when the quantum layer 50 is a red quantum layer, the quantum layer 50 converts the blue light emitted by the epitaxial layer into red light. For example, when the quantum layer 50 is a green quantum layer, the quantum layer 50 converts the blue light emitted by the epitaxial layer into green light.

[0042] In this embodiment, the LED chip does not include a substrate in the related art, which effectively reduces the design cost.

[0043] like Figure 1 As shown, the LED chip further includes a light absorbing layer 60 disposed outside the side wall of the reflective layer 40. The light absorbing layer 60 can shield the reflective layer 40 while absorbing the blue light leaked from the epitaxial layer 10, further preventing the blue light from leaking, and improving the display contrast.

[0044] like Figure 1As shown, the outer side surface 51 of the quantum layer is flush with or protrudes from the outer side surface 61 of the light absorbing layer. In this way, the quantum layer 50 completely covers the light emitting surface 101, and the quantum layer 50 can fully convert all blue light emitted from the light emitting surface 101, greatly improving the color conversion effect.

[0045] like Figure 1 As shown, the reflective layer 40 includes an inner reflective layer 41 coated on the side and bottom of the epitaxial layer 10 and an outer reflective layer 42 coated on the outer side of the inner reflective layer 41. The inner reflective layer 41 is a Bragg reflector, and the outer reflective layer 42 is ink. In this way, the inner reflective layer 41 is used to reflect the blue light emitted from the side wall of the epitaxial layer. The reflectivity of the outer reflective layer 42 is greater than 85%, and is used to reflect the blue light leaked from the inner reflective layer 41. The ink is preferably white reflective ink. The white reflective ink can effectively shield the blue light leaked from the Bragg reflector, further reduce the leakage of blue light, and improve the color purity of the converted light.

[0046] like Figure 1 As shown, the LED chip also includes a transparent protective layer 70 coated on the outside of the quantum layer 50 and the light absorbing layer 60. The transparent protective layer 70 protects the side wall of the quantum layer 50, blocks the intrusion of water vapor into the quantum layer 50 and the epitaxial layer 10, avoids the failure of the quantum dots of the edge of the quantum layer 50 caused by the intrusion of water vapor, and prolongs the service life of the LED chip. The light absorbing layer 60 is preferably black ink or colloid, which is used to absorb the blue light leaked from the outer reflection layer 42. The transparent protective layer 70 is preferably a film layer with good airtightness such as SiO2 or SiN or parylene.

[0047] like Figure 1 As shown, the epitaxial layer 10 includes a first gallium nitride layer 12, a quantum well 13 and a second gallium nitride layer 14 arranged in sequence from the top surface to the bottom surface. In this way, after the first electrode 21 and the second electrode 22 are energized, the epitaxial layer 10 can emit blue light with a main wavelength of 440nm to 475nm. A first mounting hole 111 is provided on the second gallium nitride layer 14, and a second mounting hole 112 corresponding to the first mounting hole 111 is provided on the quantum well 13. The first electrode 21 is conductively connected to the second gallium nitride layer 14, and part of the second electrode 22 is penetrated in the first mounting hole 111 and the second mounting hole 112 and is conductively connected to the first gallium nitride layer 12. The first electrode is the positive electrode of the LED, and the second electrode 22 is the negative electrode of the LED. The first electrode is conductively connected to the second gallium nitride layer 14 to form an electrical connection. Part of the second electrode 22 is penetrated in the first mounting hole 111 and the second mounting hole 112 to form an electrical connection between the second electrode and the first gallium nitride layer 12.

[0048] Of course, in an embodiment not shown in the figure, the first electrode may be the negative electrode of the LED, and the second electrode may be the positive electrode of the LED.

[0049] The LED chip further includes an insulating layer 30. The insulating layer 30 includes a first insulating portion disposed between the bottom surface of the epitaxial layer 10 and the reflective layer 40 and a second insulating portion disposed between the epitaxial layer 10 and the second electrode 22. The first insulating portion isolates the side surface of the first electrode 21 from the reflective layer 40, and the second electrode 22 is isolated from the side wall of the first mounting hole 111 and the side wall of the second mounting hole 112 by the second insulating portion.

[0050] The LED chip further includes a guide layer 80 between the first electrode 21 and the second gallium nitride layer 14. The guide layer 80 is provided to facilitate directing the current of the first electrode 21 to the second gallium nitride layer 14. The guide layer 80 is preferably a conductive glass, silver nanowire, or graphene transparent high-conductivity material.

[0051] The guide layer 80 is located at the side of the second insulating portion, so that the second electrode 22 of the guide layer 80 can be isolated by the second insulating portion.

[0052] The present application also provides an LED display device. The LED display device of this embodiment includes a substrate and a plurality of display units fixed to the substrate. Each display unit includes a plurality of LED chips, and the LED chips are the above-mentioned LED chips. Since the above-mentioned LED chips can solve the problem of poor color conversion effect caused by leakage of blue light when blue light LED excites quantum dots in the related art, the LED display device with the LED chip can solve the same technical problem. The above-mentioned display unit is a pixel body.

[0053] The present application also provides a method for processing an LED chip, which is used to process the above-mentioned LED chip. Figures 2 to 16 As shown, the LED chip processing method of this embodiment includes the following steps: step S10, arranging the epitaxial layer 10 on the substrate 1, and obtaining the first electrode 21 and the second electrode 22 connected to the epitaxial layer 10; step S20, coating the reflective layer 40 on the side and bottom of the epitaxial layer 10 and avoiding the first electrode 21 and the second electrode 22; step S30, removing the substrate 1; step S40, after removing the substrate 1, forming the quantum layer 50 on the light-emitting surface 101 of the epitaxial layer 10. In this way, after the first electrode 21 and the second electrode 22 are energized, the epitaxial layer 10 emits blue light. Since the reflective layer 40 is coated on the side and bottom of the epitaxial layer 10, the reflective layer 40 reflects the blue light emitted by the epitaxial layer 10, so that the blue light emitted by the epitaxial layer 10 is concentrated and emitted from the light-emitting surface 101, effectively reducing the blue light leakage, so that more blue light passes through the quantum layer 50 for color conversion, and improves the color conversion effect. Therefore, the technical solution of this embodiment can solve the problem in the related art that when the blue light LED excites the quantum dots, the blue light leaks out, resulting in poor color conversion effect.

[0054] like Figure 2 , Figures 10 to 12 As shown, between the step of covering the reflective layer 40 on the side and bottom of the epitaxial layer 10 and avoiding the first electrode 21 and the second electrode 22 and the step of removing the substrate 1, the processing method further includes: forming a light absorbing layer 60 outside the side of the reflective layer 40. The light absorbing layer 60 can shield the reflective layer 40 while absorbing the blue light leaked from the epitaxial layer 10, thereby further preventing the blue light from leaking.

[0055] like Figure 2 , Figures 12 to 15 As shown, after removing the substrate 1, the step of forming the quantum layer 50 on the light-emitting surface 101 of the epitaxial layer 10 includes: after removing the substrate 1, placing the first electrode 21 and the second electrode 22 downward on the temporary substrate 2 to form the quantum layer 50 on the light-emitting surface 101 of the epitaxial layer 10. The temporary substrate 2 can serve as a carrier for placing the first electrode 21 and the second electrode 22, supporting the first electrode 21, the second electrode 22 and the epitaxial layer 10, so as to facilitate the formation of the quantum layer 50 on the light-emitting surface 101. The temporary substrate 2 can be a flexible film or a rigid material.

[0056] like Figure 2 , Fig.15 and Fig.16 As shown, after the step of forming the quantum layer 50 on the light emitting surface 101 of the epitaxial layer 10, the processing method further includes: coating the outer side of the quantum layer 50 and the light absorbing layer 60 with a transparent protective layer 70. The transparent protective layer 70 protects the side wall of the quantum layer 50, blocks the intrusion of water vapor into the quantum layer 50 and the epitaxial layer 10, and prolongs the service life of the LED chip.

[0057] like Figures 2 to 16 As shown, the specific steps of the processing method of the above LED chip are as follows:

[0058] (1) An epitaxial layer 10 including a first gallium nitride layer 12, a quantum well 13 and a second gallium nitride layer 14 is used, and the epitaxial layer 10 is placed on a substrate 1, wherein the substrate 1 is made of Al2O3 (aluminum oxide); the first gallium nitride layer 12, the quantum well 13 and the second gallium nitride layer 14 are arranged in sequence from the top surface to the bottom surface of the epitaxial layer 10;

[0059] (2) partially etching the epitaxial layer 10 by a photolithography process to form a mounting hole 11, so as to expose a portion of the plurality of first gallium nitride layers 12, wherein the first mounting hole 111 and the second mounting hole 112 of the LED chip together form the mounting hole 11;

[0060] (3) Using an evaporation or sputtering process to cover a portion of the second gallium nitride layer 14 with a guide layer 80;

[0061] (4) forming a first electrode 21 on the guide layer 80 by evaporation, electroplating or sputtering;

[0062] (5) Using an evaporation or sputtering process, the insulating layer 30 is covered on the side wall of the mounting hole 11 and another part of the second gallium nitride layer 14;

[0063] (6) Using a vapor deposition, electroplating or sputtering process, a portion of the second electrode 22 is inserted into the mounting hole 11 with the insulating layer 30, a portion of the second electrode 22 is directly in contact with the first gallium nitride layer 12 for electrical connection, and another portion of the second electrode 22 is located outside the insulating layer 30;

[0064] (7) etching the epitaxial layer 10 by using a photolithography and etching process to expose a portion of the surface of the substrate 1 and make the side surface of the first gallium nitride layer 12 flush with the side surface of the second gallium nitride layer 14;

[0065] (8) Using an evaporation or sputtering process, the inner reflection layer 41 is covered on the outer side surface of the epitaxial layer 10 and the exposed insulating layer 30;

[0066] (9) Using a process such as film pressing or glue injection, the outer reflective layer 42 is covered on the outer side of the inner reflective layer 41. The outer reflective layer 42 can be made of white reflective ink;

[0067] (10) Filling the light absorbing layer 60 on the outer side of the outer reflective layer 42 by using a film pressing or glue injection process;

[0068] (11) Using a temporary substrate 2 as a support; placing the first electrode 21 and the second electrode 22 downward on the temporary substrate 2, removing the substrate 1 by a laser lift-off process, exposing the complete surface of the first gallium nitride layer 12 away from the insulating layer 30, which is the top surface of the epitaxial layer 10, i.e., the light emitting surface 101;

[0069] (12) taking a quantum layer 50 of a quantum dot film, and using a transparent heat-resistant adhesive to adhere the quantum layer 50 to the surface of the first gallium nitride layer 12; or covering the quantum layer 50 of a mixture of quantum dots and glue on the surface of the first gallium nitride layer 12 by dispensing, molding, or pouring, wherein the quantum dots are quantum dot powders, and the glue is epoxy or silicone;

[0070] (13) cutting the entire epitaxial layer 10 to form three independent LED chips not covered by the transparent protective layer 70;

[0071] (14) Sputtering, evaporation, vacuum coating and other processes are used to wrap the transparent protective layer 70 on the surface of the first gallium nitride layer 12, the light absorbing layer 60 and part of the outer reflective layer 42, and the transparent protective layer 70 avoids the first electrode 21 and the second electrode 22 to obtain an LED chip.

[0072] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0073] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0074] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An LED chip, characterized in that: include: An epitaxial layer (10), the top surface of the epitaxial layer (10) forming a light emitting surface (101); A first electrode (21) and a second electrode (22), wherein the first electrode (21) and the second electrode (22) are arranged at a distance from each other on the bottom surface of the epitaxial layer (10), and the first electrode (21) and the second electrode (22) are both conductively connected to the epitaxial layer (10); a reflective layer (40) covering the side and bottom surfaces of the epitaxial layer (10) and avoiding the first electrode (21) and the second electrode (22), the reflective layer (40) comprising an internal reflective layer (41) covering the side and bottom surfaces of the epitaxial layer (10) and an external reflective layer (42) covering the outer side of the internal reflective layer (41); The quantum layer (50) is arranged at the light emitting surface (101) of the epitaxial layer (10).

2. The LED chip according to claim 1, characterized in that: The LED chip further comprises a light absorbing layer (60) arranged around the outer side wall of the reflective layer (40).

3. The LED chip according to claim 2, characterized in that: The outer side surface (51) of the quantum layer is flush with or protrudes from the outer side surface (61) of the light absorbing layer.

4. The LED chip according to claim 1, characterized in that: The inner reflection layer (41) is a Bragg reflector, and the outer reflection layer (42) is ink.

5. The LED chip according to claim 2, characterized in that: The LED chip further comprises a transparent protective layer (70) covering the outer sides of the quantum layer (50) and the light absorbing layer (60).

6. The LED chip according to claim 1, characterized in that: The epitaxial layer (10) comprises a first gallium nitride layer (12), a quantum well (13) and a second gallium nitride layer (14) which are arranged in sequence from the top surface to the bottom surface, the second gallium nitride layer (14) is provided with a first mounting hole (111), the quantum well (13) is provided with a second mounting hole (112) corresponding to the first mounting hole (111), the first electrode (21) is conductively connected to the second gallium nitride layer (14), and part of the second electrode (22) is arranged in the first mounting hole (111) and the second mounting hole (112) and is conductively connected to the first gallium nitride layer (12); The LED chip further comprises an insulating layer (30), wherein the insulating layer (30) comprises a first insulating portion arranged between the bottom surface of the epitaxial layer (10) and the reflective layer (40), and a second insulating portion arranged between the epitaxial layer (10) and the second electrode (22); The LED chip further comprises a guide layer (80) located between the first electrode (21) and the second gallium nitride layer (14); the guide layer (80) is located on the side of the second insulating portion.

7. An LED display device, comprising a substrate and a plurality of display units fixed to the substrate, each of the display units comprising a plurality of LED chips, characterized in that: The LED chip is the LED chip according to any one of claims 1 to 6.

8. A method for processing an LED chip, characterized in that: For processing the LED chip according to any one of claims 1 to 6, the processing method comprises the following steps: Arranging an epitaxial layer (10) on a substrate (1), and obtaining a first electrode (21) and a second electrode (22) connected to the epitaxial layer (10); Covering the side and bottom surfaces of the epitaxial layer (10) with a reflective layer (40) while avoiding the first electrode (21) and the second electrode (22); removing the substrate (1); After removing the substrate (1), a quantum layer (50) is formed on the light-emitting surface (101) of the epitaxial layer (10).

9. The method for processing an LED chip according to claim 8, characterized in that: Between the step of covering the side and bottom surfaces of the epitaxial layer (10) with the reflective layer (40) and avoiding the first electrode (21) and the second electrode (22) and the step of removing the substrate (1), the processing method further comprises: forming a light absorption layer (60) outside the side surfaces of the reflective layer (40).

10. The processing method according to claim 8, characterized in that: After removing the substrate (1), the step of forming the quantum layer (50) on the light-emitting surface (101) of the epitaxial layer (10) comprises: after removing the substrate (1), placing the first electrode (21) and the second electrode (22) downward on a temporary substrate (2) to form the quantum layer (50) on the light-emitting surface (101) of the epitaxial layer (10).

11. The processing method according to claim 9, characterized in that: After the step of forming the quantum layer (50) on the light-emitting surface (101) of the epitaxial layer (10), the processing method further comprises: coating the outer sides of the quantum layer (50) and the light-absorbing layer (60) with a transparent protective layer (70).

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