LED chip and welding method thereof

Abstract

The present invention discloses an LED chip, including an LED epitaxial structure layer, wherein the LED epitaxial structure layer includes an N-type layer, a light-emitting layer and a P-type layer; a plurality of holes are provided in the LED epitaxial structure layer, and the holes are filled with quantum dots; a laser welding reflection layer is also provided on the LED epitaxial structure layer, and the laser welding reflection layer is used to reflect the energy of the laser. The LED chip of the present invention forms a laser welding reflection layer on the LED epitaxial layer, and the laser welding reflection layer is used to reflect the energy of the laser. When the LED chip is subsequently laser-welded with a transparent substrate, the laser welding reflection layer located on the outer layer of the LED chip can effectively reflect the energy of the laser, thereby preventing the laser from irradiating the quantum dots in the LED chip to cause the problem of quenching of the quantum dots.

Description

Technical Field

[0001] The invention relates to the field of LED display, and in particular to an LED chip and a welding method thereof. Background Art

[0002] In the related technology, LED chips are usually made of gallium nitride. LED chips made of gallium nitride can emit blue and green light, but it is difficult to produce LED chips that emit red light, which cannot meet the full-color display application in the field of LED display. At present, in small-pitch or micro-pitch LED display technology, the red light chip of the AlInGaP quaternary system is required to display full-color images. However, the production yield of the flip-chip red light chip of the AlInGaP quaternary system is low and the production cost is high. It is necessary to find other new red light chip structures that can replace the current flip-chip red light chip of the AlInGaP quaternary system.

[0003] At present, some related technologies include a porous structure with built-in quantum dots in the LED chip structure, which can convert the LED chip that normally emits blue or green light into red light through the color conversion function of quantum dots. However, when this LED chip with built-in quantum dots is used in the production process of LED display modules, the LED chip ultimately needs to be welded on the target substrate. The welding process is mainly achieved by reflow soldering or laser welding. Both of these welding methods will place the LED chip in an environment with a temperature exceeding 100°C. Different types of quantum dot materials will be quenched when the temperature reaches 100°C to 120°C, affecting the final display effect of the LED display module. For this reason, it is urgent to find a solution that can realize the welding of LED chips and target substrates without damaging the LED chips with built-in quantum dots. Summary of the invention

[0004] The object of the present invention is to provide an LED chip and a welding method thereof, which can effectively avoid the problem of quenching of quantum dots in the LED chip during laser welding.

[0005] In order to achieve the above-mentioned purpose, in the first aspect, the present invention provides an LED chip, including an LED epitaxial structure layer, the LED epitaxial structure layer includes an N-type layer, a light-emitting layer and a P-type layer; a plurality of holes are provided in the LED epitaxial structure layer, and the holes are filled with quantum dots; a laser welding reflection layer is also provided on the LED epitaxial structure layer, and the laser welding reflection layer is used to reflect the energy of the laser.

[0006] Preferably, it further comprises a substrate having a first surface and a second surface opposite to each other, and the LED epitaxial structure layer is arranged on the first surface of the substrate.

[0007] Preferably, the plurality of holes are provided in at least one of the N-type layer, the light-emitting layer and the P-type layer.

[0008] The present invention also provides an LED chip, comprising a substrate, wherein the substrate has a first surface and a second surface opposite to each other, and an LED epitaxial structure layer is arranged on the first surface of the substrate; the LED epitaxial structure layer comprises an N-type layer, a light-emitting layer and a P-type layer; a plurality of holes are arranged in the substrate, and the holes are filled with quantum dots; a laser welding reflection layer is also arranged on the LED epitaxial structure layer, and the laser welding reflection layer is used to reflect the energy of the laser.

[0009] Preferably, the hole extends from the second surface of the substrate to the first surface, and a first protective layer is further provided on the second surface of the substrate.

[0010] The present invention also provides an LED chip, comprising an LED epitaxial structure layer and a color conversion structure layer, wherein the LED epitaxial structure layer comprises an N-type layer, a light-emitting layer and a P-type layer; the LED epitaxial structure layer is bonded to the color conversion structure layer, a plurality of holes are arranged in the color conversion structure layer, and the holes are filled with quantum dots; a laser welding reflection layer is also arranged on the LED epitaxial structure layer, and the laser welding reflection layer is used to reflect the energy of the laser.

[0011] Preferably, the color conversion structure layer comprises a doping layer, a plurality of holes are arranged in the doping layer, the holes are filled with quantum dots, and a second protective layer is arranged on one side or both sides of the doping layer.

[0012] Preferably, the laser welding reflective layer is composed of a first oxide stack.

[0013] Preferably, a Bragg reflection layer is further provided on the LED epitaxial structure layer, the laser welding reflection layer is provided on the Bragg reflection layer, and the Bragg reflection layer is composed of a second oxide stack.

[0014] In a second aspect, the present invention also provides a method for welding an LED chip, the method comprising: providing the LED chip described in the first aspect, the LED chip being provided with a P-type electrode and an N-type electrode, the P-type electrode and the N-type electrode protruding from the laser welding reflective layer; providing a transparent substrate, the transparent substrate having a first substrate surface and a second substrate surface opposite to each other, the second substrate surface being provided with a circuit and a first soldering pad and a second soldering pad corresponding to the P-type electrode and the N-type electrode; mounting the transparent substrate on the LED chip and making the P-type electrode and the N-type electrode dock with the first soldering pad and the second soldering pad, respectively; irradiating a laser from the first substrate surface of the transparent substrate, the laser irradiating the connection between the first soldering pad and the P-type electrode and the connection between the N-type electrode and the second soldering pad to weld and fix the LED chip to the transparent substrate.

[0015] Compared with the prior art, the LED chip of the present invention forms a laser welding reflective layer on the LED epitaxial layer, and the laser welding reflective layer is used to reflect the energy of the laser. When the LED chip is subsequently laser welded with the transparent substrate, the laser welding reflective layer located on the outer layer of the LED chip can effectively reflect the energy of the laser, thereby preventing the laser from irradiating the quantum dots in the LED chip and causing the problem of quenching of the quantum dots. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The schematic diagram of the structure of the substrate and LED epitaxial structure layer in the LED chip of the first embodiment of the present invention is shown.

[0017] Figure 2 Shows the Figure 1 Schematic diagram of the structure of the structure formed by etching a plurality of holes and step portions.

[0018] Figure 3 Shows the Figure 2 Schematic diagram of the structure after the holes are filled with quantum dots;

[0019] Figure 4 The schematic diagram of the structure of a single LED chip in the first embodiment of the present invention is shown.

[0020] Figure 5 Shown Figure 4 Schematic diagram of the structure in which a single LED chip is welded and connected to a transparent substrate.

[0021] Figure 6 The schematic diagram of the structure of a single LED chip in the second embodiment of the present invention is shown.

[0022] Figure 7 Shown Figure 6 Schematic diagram of the structure after a single LED chip is welded and connected to a transparent substrate.

[0023] Figure 8 A schematic diagram of the structure of a single LED chip in Embodiment 3 of the present invention is shown.

[0024] Fig. 9 Shown Figure 8 Schematic diagram of the structure after a single LED chip is welded and connected to a transparent substrate.

[0025] Fig.10 The schematic diagram of the structure of the LED chip in the fourth embodiment of the present invention is shown.

[0026] Fig.11 Another structural schematic diagram of the LED chip in Embodiment 4 of the present invention is shown.

[0027] Fig.12 Shown Fig.10Schematic diagram of the structure after a single LED chip is welded and connected to a transparent substrate. DETAILED DESCRIPTION

[0028] In order to explain the technical content, structural features and achieved effects of the present invention in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0029] Embodiment 1

[0030] like Figures 1 to 4 As shown, an embodiment of the present invention provides an LED chip 1000, including an LED epitaxial structure layer, wherein the LED epitaxial structure layer includes an N-type layer 4, a light-emitting layer 5 and a P-type layer 6; a plurality of holes 7 are provided in the LED epitaxial structure layer, and quantum dots 8 are filled in the holes 7; a laser welding reflection layer 12 is also provided on the LED epitaxial structure layer, and the laser welding reflection layer 12 is used to reflect the energy of the laser.

[0031] Specifically, in the embodiment of the present invention, Figure 1 to Figure 2 As shown, the LED epitaxial structure layer includes a buffer layer 2, an intrinsic layer 3, an N-type layer 4, a light-emitting layer 5 and a P-type layer 6 arranged in sequence from bottom to top, the hole 7 extends from the upper surface of the P-type layer 6 to the N-type layer 4, and the height of the quantum dot 8 is lower than the depth of the hole 7.

[0032] The LED chip 1000 of the embodiment of the present invention forms a laser welding reflective layer 12 on the LED epitaxial layer, and the laser welding reflective layer 12 is used to reflect the energy of the laser. When the LED chip 1000 is subsequently laser welded with the transparent substrate 17, the laser welding reflective layer 12 located on the outer layer of the LED chip 1000 can effectively reflect the energy of the laser, thereby preventing the laser from irradiating the quantum dots 8 in the LED chip 1000 and causing the quantum dots 8 to be quenched.

[0033] In the embodiment of the present invention, the LED chip 1000 further includes a substrate 1 having a first surface 1a and a second surface 1b opposite to each other. The LED epitaxial structure layer is provided on the first surface 1a of the substrate 1. Specifically, the substrate 1 is a sapphire substrate.

[0034] In some other embodiments, the LED chip 1000 may also be without the substrate 1, and the substrate 1 can be peeled off after the LED chip 1000 is processed.

[0035] It should be noted that the plurality of holes 7 can be arranged in at least one layer among the N-type layer 4, the light-emitting layer 5 and the P-type layer 6. For example, the plurality of holes 7 are arranged in the N-type layer 4 and the light-emitting layer 5, and quantum dots 8 are filled in the holes 7, and the P-type layer 6 covers the light-emitting layer 5 and the quantum dots 8.

[0036] In an embodiment of the present invention, the laser welding reflection layer 12 is composed of a first oxide stack; a Bragg reflection layer 11 is also provided on the LED epitaxial structure layer, and the laser welding reflection layer 12 is provided on the Bragg reflection layer 11, and the Bragg reflection layer 11 is composed of a second oxide stack; the single layer thickness of the first oxide stack is different from the single layer thickness of the second oxide stack of the Bragg reflection layer 11, and the overall thickness of the first oxide stack is different from the overall thickness of the second oxide stack of the Bragg reflection layer 11.

[0037] Specifically, Figures 1 to 4 As shown, a raised step portion 9 is provided in the LED epitaxial structure layer, a transparent conductive layer 10 is provided in the area other than the step portion 9 on the P-type layer 6, the transparent conductive layer 10 covers the P-type layer 6 and the quantum dot 8, a P-type electrode 13 is further provided on the transparent conductive layer 10, an N-type electrode 14 is further provided on the step portion 9, the N-type electrode 14 covers the step portion 9 and is connected to the N-type layer 4; a Bragg reflection layer 11 is provided on the transparent conductive layer 10, the Bragg reflection layer 11 covers the transparent conductive layer 10, the N-type layer 4 and the first surface 1a of the sapphire substrate 1, the Bragg reflection layer 11 is a second oxide stacked structure, and the second oxide stacked structure is SiO 2 / Ti 3 O 5 The first oxide stack is also SiO 2 / Ti 3 O 5 A stacked structure, which has the same composition as the Bragg reflection layer 11, but the single layer thickness of the first oxide stack is different from the single layer thickness of the second oxide stack of the Bragg reflection layer 11, and the overall thickness of the first oxide stack is different from the overall thickness of the second oxide stack of the Bragg reflection layer 11. This structure realizes reflection of different light wavelengths and has a better reflection effect, and avoids the laser penetrating the laser welding reflection layer 12 and the Bragg reflection layer 11 into the quantum dot 8 area during laser welding, resulting in quenching of the quantum dot 8.

[0038] In some other embodiments, the first oxide stack and the second oxide stack may have different compositions. In addition, the thickness of each single layer in the first oxide stack and the second oxide stack may be set according to actual needs.

[0039] The following Figures 1 to 4 The preparation method of the LED chip 1000 is specifically introduced.

[0040] The embodiment of the present invention further discloses a method for preparing an LED chip 1000, the method comprising the following steps:

[0041] S1. Provide a substrate 1, wherein the substrate 1 has a first surface 1a and a second surface 1b opposite to each other, and form an LED epitaxial structure layer on the first surface 1a of the substrate 1; specifically, Figure 1 As shown, a vapor phase epitaxy device, such as MOCVD equipment, is used to epitaxially grow LED epitaxial structure layers on a substrate 1, including a buffer layer 2, an intrinsic layer 3, an N-type layer 4, a light-emitting layer 5 and a P-type layer 6 grown in sequence.

[0042] S2, etching a plurality of holes 7 in the LED epitaxial structure layer, and filling the holes 7 with quantum dots 8; specifically, Figures 2 to 3 As shown, after step S1, a step portion 9 is formed on the LED epitaxial structure layer to expose the N-type layer 4 and the LED epitaxial structures are divided into independent LED epitaxial structures. Then, an etching process is used to form a plurality of holes 7 on the LED epitaxial structure layer, and quantum dots 8 are filled in the holes 7. The filling height of the quantum dots 8 is preferably lower than the depth of the holes 7.

[0043] S3, a Bragg reflection layer 11 is also provided on the LED epitaxial structure layer, and a laser welding reflection layer 12 is formed on the Bragg reflection layer 11, and the laser welding reflection layer 12 is used to reflect the energy of the laser. Figure 4 shown.

[0044] In the embodiment of the present invention, in step S1, the step of etching a plurality of holes 7 in the LED epitaxial structure layer includes: the LED epitaxial layer includes an epitaxially grown N-type layer 4, a light-emitting layer 5 and a P-type layer 6, and at least one of the N-type layer 4, the light-emitting layer 5 and the P-type layer 6 is etched to form the plurality of holes 7, specifically, Figure 2 As shown, a plurality of holes 7 are formed by etching from the P-type layer 6 to the N-type layer 4 , and the bottoms of the holes 7 are located in the N-type layer 4 .

[0045] In the embodiment of the present invention, Figures 1 to 4 As shown, after step S1, a transparent conductive layer 10 is formed on the P-type layer 6 in an area other than the step portion 9, the transparent conductive layer 10 covers the P-type layer 6 and the quantum dot 8, a P-type electrode 13 is formed on the transparent conductive layer 10, and an N-type electrode 14 is formed at the step portion 9, the N-type electrode 14 covers the step portion 9 and is connected to the N-type layer 4; after the P-type electrode 13 and the N-type electrode 14 are formed, a second oxide stack is deposited by physical vapor deposition (PVD) to form a Bragg reflection layer 11, the Bragg reflection layer 11 covers the transparent conductive layer 10, the N-type layer 4 and the first surface 1a of the substrate 1, and the Bragg reflection layer 11 is SiO 2 / Ti 3 O 5 Laminated structure.

[0046] In some other embodiments, the holes 7 are arranged in one or two of the N-type layer 4, the light-emitting layer 5 and the P-type layer 6. For example, after the N-type layer 4 and the light-emitting layer 5 are epitaxially grown on the substrate 1, a plurality of holes 7 are formed by etching from the light-emitting layer 5 into the N-type layer 4, and quantum dots 8 are filled in the holes 7. After the quantum dots 8 are filled, the P-type layer 6 is epitaxially grown on the light-emitting layer 5, and the P-type layer 6 covers the light-emitting layer 5 and the quantum dots 8.

[0047] In the embodiment of the present invention, Figure 4 As shown, the steps of forming a laser welding reflection layer 12 on the Bragg reflection layer 11 include:

[0048] S31. Depositing a first oxide stack on the Bragg reflection layer 11 by physical vapor deposition; the single layer thickness of the first oxide stack is different from the single layer thickness of the second oxide stack of the Bragg reflection layer 11, and the overall thickness of the first oxide stack is different from the overall thickness of the second oxide stack of the Bragg reflection layer 11. By making the single layer thickness and the overall thickness of the oxide stack in the Bragg reflection layer 11 and the laser welding reflection layer 12 different, reflection of different light wavelengths is achieved, and the reflection effect is better, so as to avoid the laser penetrating the laser welding reflection layer 12 and the Bragg reflection layer 11 into the quantum dot 8 area during laser welding, thereby preventing the quantum dot 8 from being quenched.

[0049] S32. The first oxide stack constitutes the laser welding reflective layer 12.

[0050] In the embodiment of the present invention, the first oxide stack is SiO 2 / Ti 3 O 5 The first oxide stack structure has the same composition as the Bragg reflection layer 11. In other embodiments, the compositions of the first oxide stack and the second oxide stack may be different. In addition, the thickness of each single layer in the first oxide stack and the second oxide stack may be set according to actual needs.

[0051] The method for preparing the LED chip 1000 of the present invention further includes the following steps:

[0052] S4, thinning and cutting the second surface 1b of the substrate 1 to form a single LED chip 1000. The specific structure of the single LED chip 1000 is as follows: Figure 4 Of course, for an LED chip without a substrate 1, a single LED chip can be formed by simply peeling off the substrate using a laser peeling method.

[0053] Embodiment 2

[0054] like Figure 6 to Figure 7As shown, this embodiment discloses an LED chip 2000 , which is different from the first embodiment in that the position of the quantum dots 108 is different. The quantum dots 108 in this embodiment are located in the substrate 101 .

[0055] Specifically, before preparing the hole 107, the substrate 101 is first thinned. The thinned substrate 101 has a first surface 101a and a second surface 101b relative to each other. The hole 107 extends from the second surface 101b of the substrate 101 to the first surface 101a. A first protective layer 116 is also provided on the second surface 101b of the substrate 101 to protect the quantum dots 108. The LED epitaxial structure layer includes a buffer layer 102, an intrinsic layer 103, an N-type layer 104, a light-emitting layer 105, a P-type layer 106, a step portion 109, a transparent conductive layer 110, a P-type electrode 113, an N-type electrode 114, a Bragg reflection layer 111 and a laser welding reflection layer 112. The preparation method of the buffer layer 102, the intrinsic layer 103, the N-type layer 104, the light-emitting layer 105, the P-type layer 106, the step portion 109, the transparent conductive layer 110, the P-type electrode 113, the N-type electrode 114, the Bragg reflection layer 111 and the laser welding reflection layer 112 is the same as that in Example 1.

[0056] After the LED chip 2000 is prepared, a single LED chip 2000 can be obtained by directly cutting it.

[0057] Specifically, the first protection layer 116 may be an aluminum oxide layer prepared by an atomic layer deposition (ALD) method.

[0058] In some other embodiments, the hole 107 may also extend from the first surface 101a of the substrate 101 to the second surface 101b without penetrating the second surface 101b. In this case, there is no need to set a first protective layer 116 on the second surface 101b of the substrate 101 to protect the quantum dots 108.

[0059] Embodiment 3

[0060] like Figures 8 to 9As shown, this embodiment discloses an LED chip 3000, which is different from the first embodiment in that the position of the quantum dot 208 is different. In this embodiment, the LED chip 3000 includes a substrate 201, an LED epitaxial structure layer and a color conversion structure layer. The LED epitaxial structure layer is arranged on the first surface 201a of the substrate 201, and the color conversion structure layer is arranged on the second surface 201b of the substrate 201. A plurality of holes 207 are arranged in the color conversion structure layer, and the holes 207 are filled with quantum dots 208. Specifically, The color conversion structure layer includes a doping layer 215, wherein a plurality of holes 207 are provided in the doping layer 215, wherein the holes 207 are filled with quantum dots 208, and the quantum dots 208 are located below the second surface 201b of the substrate 201. First, the substrate 201 is thinned from the second surface 201b of the substrate 201; then, a doping layer 215 is provided on the second surface 201b of the substrate 201, wherein the doping layer 215 has a first surface 215a and a second surface 215b opposite to each other, wherein the first surface 215 a is connected to the second surface 201b of the substrate 201, the second surface 215b of the doping layer 215 is provided with a plurality of holes 207 extending to the inner side of the doping layer 215, and the holes 207 are filled with quantum dots 208; the second surface 215b of the doping layer 215 is provided with a second protective layer 216 to protect the quantum dots 208, and the doping layer 215 and the second protective layer 216 can be used as the color conversion structure layer of the LED chip 3000; the LED epitaxial structure layer includes a buffer layer 202, an intrinsic layer 20 3. The preparation method of the N-type layer 204, the light-emitting layer 205, the P-type layer 206, the step portion 209, the transparent conductive layer 210, the P-type electrode 213, the N-type electrode 214, the Bragg reflection layer 211 and the laser welding reflection layer 212, the buffer layer 202, the intrinsic layer 203, the N-type layer 204, the light-emitting layer 205, the P-type layer 206, the step portion 209, the transparent conductive layer 210, the P-type electrode 213, the N-type electrode 214, the Bragg reflection layer 211 and the laser welding reflection layer 212 is the same as that in Example 1.

[0061] Specifically, the doping layer 215 is a gallium nitride doping layer 215, and the second protective layer 216 may be an aluminum oxide layer prepared by an atomic layer deposition (ALD) method. The second protective layer 216 may also be another substrate, such as a sapphire substrate.

[0062] Embodiment 4

[0063] like Figure 10 to Figure 11 As shown, this embodiment discloses an LED chip 4000, which is different from the third embodiment in that the LED chip 4000 does not have a substrate 201 (refer to Fig. 9In this embodiment, the LED chip 4000 includes an LED epitaxial structure layer and a color conversion structure layer, and the light emitting surface of the LED epitaxial structure layer is bonded to the color conversion structure layer.

[0064] like Fig.10 As shown, the LED chip 4000 has no substrate. In this embodiment, a buffer layer, an intrinsic layer 303, an N-type layer 304, a light-emitting layer 305, a P-type layer 306, a step portion 309, a transparent conductive layer 310, a P-type electrode 313, an N-type electrode 314, a Bragg reflection layer 311 and a laser welding reflection layer 312 are first manufactured on the substrate, and then the buffer layer is irradiated by a laser lift-off process to lift off the substrate; the second protective layer 316 is used as another substrate, and a doping layer 315 with quantum dots 308 is manufactured on the second protective layer 316 to form a color conversion structure layer, and finally, the color conversion structure layer is bonded to the intrinsic layer 303 to form a whole; or, as Fig.11 As shown, another second protective layer 316 may be further disposed on the doping layer 315 , and then the second protective layer 316 is bonded to the intrinsic layer 303 to form a whole.

[0065] Embodiment 5

[0066] Embodiments 1 to 4 are detailed descriptions of an LED chip structure provided by the present invention. Figure 5 , Figure 7 , Fig. 9 and Fig.12 A method for welding an LED chip provided by embodiments 1 to 4 of the present invention is described. The welding method comprises:

[0067] S101. Provide the LED chips 1000, 2000, 3000, 4000 in the above embodiments, wherein the LED chips 1000, 2000, 3000, 4000 are provided with P-type electrodes 13, 113, 213, 313 and N-type electrodes 14, 114, 214, 314, and the P-type electrodes 13, 113, 213, 313 and N-type electrodes 14, 114, 214, 314 protrude from the laser welding reflective layer 12, 112, 212, 312.

[0068] S102, provide a transparent substrate 17, 117, 217, 317, wherein the transparent substrate 17, 117, 217, 317 has a first substrate surface 17a, 117a, 217a, 317a and a second substrate surface 17b, 117b, 217b, 317b relative to each other, and the second substrate surface 17b, 117b, 217b, 317b is provided with a circuit and a first welding pad 18, 118, 218, 318 and a second welding pad 19, 119, 219, 319 corresponding to the P-type electrode 13, 113, 213, 313 and the N-type electrode 14, 114, 214, 314; the use of the transparent substrate 17, 117, 217, 317 can effectively ensure that the laser penetrates the transparent substrate 17, 117, 217, 317 and advances for welding.

[0069] S103, install the transparent substrate 17, 117, 217, 317 on the LED chip 1000, 2000, 3000, 4000 and make the P-type electrode 13, 113, 213, 313 dock with the first pad 18, 118, 218, 318, and the N-type electrode 14, 114, 214, 314 dock with the second pad 19, 119, 219, 319.

[0070] S104, irradiate the first substrate surface 17a, 117a, 217a, 317a of the transparent substrate 17, 117, 217, 317 with a laser 20, 120, 220, 320, and irradiate the connection between the first soldering pad 18, 118, 218, 318 and the P-type electrode 13, 113, 213, 313 and the connection between the N-type electrode 14, 114, 214, 314 and the second soldering pad 19, 119, 219, 319 to weld and fix the LED chip 1000, 2000, 3000, 4000 to the transparent substrate 17, 117, 217, 317.

[0071] The laser welding method of the embodiment of the present invention can prevent the temperature of the LED chips 1000, 2000, 3000, 4000 from being too high during laser 20, 120, 220, 320 welding, which may cause quenching of the quantum dots 8, 108, 208, 308, and effectively protect the LED chips 1000, 2000, 3000, 4000, thereby ensuring a better final presentation effect of the LED display.

[0072] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention still fall within the scope covered by the present invention.

Claims

1. An LED chip, characterized in that: It includes an LED epitaxial structure layer, wherein the LED epitaxial structure layer includes an N-type layer, a light-emitting layer and a P-type layer; A plurality of holes are provided in the LED epitaxial structure layer, and the holes are filled with quantum dots; A laser welding reflection layer is also provided on the LED epitaxial structure layer, and the laser welding reflection layer is used to reflect the energy of the laser when the LED chip is laser welded to the transparent substrate, and the laser welding reflection layer is composed of a first oxide stack; A Bragg reflection layer is also provided on the LED epitaxial structure layer, the laser welding reflection layer is provided on the Bragg reflection layer, and the Bragg reflection layer is composed of a second oxide stack; The first oxide stack is a SiO2 / Ti3O5 stack structure, the second oxide stack structure is a SiO2 / Ti3O5 stack structure, the single layer thickness of the first oxide stack is different from the single layer thickness of the second oxide stack of the Bragg reflector layer, and the overall thickness of the first oxide stack is different from the overall thickness of the second oxide stack of the Bragg reflector layer.

2. The LED chip according to claim 1, characterized in that: The invention also includes a substrate having a first surface and a second surface opposite to each other, and the LED epitaxial structure layer is disposed on the first surface of the substrate.

3. The LED chip according to any one of claims 1 to 2, characterized in that: The plurality of holes are disposed in at least one of the N-type layer, the light-emitting layer and the P-type layer.

4. An LED chip, characterized in that: The method comprises a substrate having a first surface and a second surface opposite to each other, and an LED epitaxial structure layer is arranged on the first surface of the substrate; the LED epitaxial structure layer comprises an N-type layer, a light-emitting layer and a P-type layer; A plurality of holes are provided in the substrate, and the holes are filled with quantum dots; A laser welding reflection layer is also provided on the LED epitaxial structure layer, and the laser welding reflection layer is used to reflect the energy of the laser, and the laser welding reflection layer is composed of a first oxide stack; A Bragg reflection layer is also provided on the LED epitaxial structure layer, the laser welding reflection layer is provided on the Bragg reflection layer, and the Bragg reflection layer is composed of a second oxide stack; The first oxide stack is a SiO2 / Ti3O5 stack structure, the second oxide stack structure is a SiO2 / Ti3O5 stack structure, the single layer thickness of the first oxide stack is different from the single layer thickness of the second oxide stack of the Bragg reflector layer, and the overall thickness of the first oxide stack is different from the overall thickness of the second oxide stack of the Bragg reflector layer.

5. The LED chip according to claim 4, characterized in that: The hole extends from the second surface of the substrate to the first surface, and a first protective layer is also disposed on the second surface of the substrate.

6. An LED chip, characterized in that: It includes an LED epitaxial structure layer and a color conversion structure layer, wherein the LED epitaxial structure layer includes an N-type layer, a light-emitting layer and a P-type layer; the LED epitaxial structure layer is bonded to the color conversion structure layer, and a plurality of holes are provided in the color conversion structure layer, and the holes are filled with quantum dots; A laser welding reflection layer is also provided on the LED epitaxial structure layer, and the laser welding reflection layer is used to reflect the energy of the laser, and the laser welding reflection layer is composed of a first oxide stack; A Bragg reflection layer is also provided on the LED epitaxial structure layer, the laser welding reflection layer is provided on the Bragg reflection layer, and the Bragg reflection layer is composed of a second oxide stack; The first oxide stack is a SiO2 / Ti3O5 stack structure, the second oxide stack structure is a SiO2 / Ti3O5 stack structure, the single layer thickness of the first oxide stack is different from the single layer thickness of the second oxide stack of the Bragg reflector layer, and the overall thickness of the first oxide stack is different from the overall thickness of the second oxide stack of the Bragg reflector layer.

7. The LED chip according to claim 6, characterized in that: The color conversion structure layer comprises a doping layer, a plurality of holes are arranged in the doping layer, quantum dots are filled in the holes, and a second protective layer is arranged on one side or both sides of the doping layer.

8. A method for welding an LED chip, characterized in that: The welding method comprises: Providing an LED chip according to any one of claims 1 to 7, wherein a P-type electrode and an N-type electrode are provided on the LED chip, and the P-type electrode and the N-type electrode protrude from the laser welding reflective layer; Providing a transparent substrate, wherein the transparent substrate has a first substrate surface and a second substrate surface opposite to each other, wherein a circuit and a first pad and a second pad corresponding to a P-type electrode and an N-type electrode are provided on the second substrate surface; Mounting the transparent substrate on the LED chip and making the P-type electrode and the N-type electrode dock with the first pad and the second pad respectively; The laser is irradiated from the first substrate surface of the transparent substrate, and the laser is irradiated at the connection between the first pad and the P-type electrode and the connection between the N-type electrode and the second pad to weld and fix the LED chip to the transparent substrate.

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