White light package adopting blue-green double-peak single crystal chip

Abstract

The utility model relates to the technical field of semiconductor photoelectronics, and provides a white light package adopting a blue-green double-peak single crystal chip, which comprises a package structure and an LED chip arranged in the package structure. The LED chip comprises a substrate, a blue-green double-peak single crystal chip and a red light conversion layer which are sequentially stacked from bottom to top, the blue-green double-peak single crystal chip comprises an electroluminescent blue light quantum well layer and a photoluminescent green light conversion layer, and the red light conversion layer comprises a red light wavelength conversion material containing perovskite quantum dots. A red light wavelength conversion material containing perovskite quantum dots is arranged in the red light conversion layer, the light absorption coefficient of the perovskite material is 105cm <-1 > magnitude, a backlight source with an extremely high display color gamut can be obtained, the color gamut can reach more than 100% of NTSC, the color gamut is far larger than the color gamut which can be achieved by a traditional red light fluorescent powder layer, and the display color gamut of the LED chip is further improved.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor optoelectronic technology, and more specifically, to a white light package using a blue-green dual-peak single crystal chip. Background Art

[0002] LED combines the advantages of low power consumption, high brightness, high resolution, high color saturation, fast response speed, long life, and high efficiency, and is widely used in the field of display technology. Among them, the mini-LED combined with a new driving and power management method as a backlight technology for local dimming is adopted by the liquid crystal display industry and achieves a higher dynamic range (HDR), which is widely regarded as the next major trend in the field of display technology.

[0003] In order to achieve a wide color gamut backlight display, more pure and narrower full-width at half-maximum red, green, and blue primary colors are required. Among the common methods is a blue chip plus narrow-peak-width red and green fluorescent powders. However, due to limited selection of narrow-peak-width green powder materials, there are limitations in wavelength, reliability, cost, etc.

[0004] Another solution is a packaging form that uses a separate blue chip and green chip, combined with a red fluorescent powder. When making a backlight with a lens, this solution is prone to uneven spatial distribution and the appearance of blue and green spots; in addition, during use, as the two chips have different peak shifts with temperature changes or during use, color point offsets will also occur, especially during the aging process, color drift is more likely to occur.

[0005] Therefore, the existing technology still needs to be improved and developed. Summary of the Utility Model

[0006] The purpose of the utility model is to provide a white light package using a blue-green dual-peak single crystal chip to solve the technical problems of low color gamut, uneven light color distribution, and easy appearance of color difference and color drift in the existing LED white light source.

[0007] To achieve the above purpose, the utility model provides a white light package using a blue-green dual-peak single crystal chip, including a packaging structure and an LED chip disposed in the packaging structure;

[0008] The LED chip includes a substrate, a blue-green dual-peak single crystal chip, and a red light conversion layer stacked in sequence from bottom to top. The blue-green dual-peak single crystal chip includes an electroluminescent blue light quantum well layer and a photoluminescent green light conversion layer. The red light conversion layer includes a red light wavelength conversion material including perovskite quantum dots.

[0009] Furthermore, the red light conversion layer further includes a red light wavelength conversion material of any one or a combination of cadmium selenide quantum dots, indium phosphide quantum dots, and cadmium sulfide quantum dots.

[0010] Further, the red light conversion layer is a thin film layer stacked on the blue-green dual-peak single crystal chip, and the thickness of the perovskite quantum dot material or its mixture with the carrier in the red light conversion layer is 10-250 microns.

[0011] In some embodiments, the blue and green light emitted by the blue-green dual-peak single crystal chip is directed towards the red light conversion layer to pump the red light wavelength conversion material, so that the red light wavelength conversion material emits red light.

[0012] Further, the red light conversion layer is stacked and covered on the blue-green dual-peak single crystal chip by means of dispensing, injection molding, evaporation coating or inkjet printing.

[0013] In some embodiments, the blue-green dual-peak single crystal chip includes a gallium nitride layer, the gallium nitride layer includes an n-type gallium nitride layer and a p-type gallium nitride layer, and InxGa1-xN / GaN quantum well layers are grown on both the polar and non-polar surfaces of the n-type gallium nitride layer.

[0014] Further, the packaging structure includes a lens and a circuit board, and the lens packages the LED chip on the circuit board by means of SMT packaging or COB packaging.

[0015] The beneficial effects of the white light packaging using the blue-green dual-peak single crystal chip and its preparation method provided by the present utility model are at least as follows: By directly growing a blue light quantum well layer that emits blue light electro-optically and a green light conversion layer that emits green light photo-optically on the gallium nitride layer, a blue-green dual-peak single crystal chip with an integrated structure is formed. The blue-green dual-peak single crystal chip can simultaneously emit blue light and green light with blue-green dual peaks when the blue light quantum well layer is driven by current. Compared with the traditional method of separately setting a blue light chip and a green light chip, the problem of integrated transfer of multiple-color micro LEDs is avoided, the preparation process is simple and easy to produce. Moreover, when used as a backlight source, the spatial distribution of the blue light quantum well layer and the green light conversion layer is uniform, greatly reducing the risk of blue and green spots. During use, as the LED chip changes with temperature, no color point shift will occur, reducing the probability of color drift, and thus improving the color gamut of the LED chip.

[0016] The red light wavelength conversion material including perovskite quantum dots is provided in the red light conversion layer, and the light absorption coefficient of the perovskite material is on the order of 10 5 cm -1 magnitude, and a backlight source with an extremely high display color gamut can be obtained. The color gamut can reach more than 100% of NTSC, which is much larger than the color gamut that can be achieved by the traditional red light phosphor layer, further improving the display color gamut of the LED chip. Description of the Drawings

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0018] Figure 1 A schematic structural diagram of a white light package using a blue-green dual-peak single crystal chip provided by an embodiment of the present invention;

[0019] Figure 2 A schematic structural diagram of an LED chip provided by an embodiment of the present invention;

[0020] Figure 3 A flowchart of a preparation method for a white light package provided by an embodiment of the present invention;

[0021] Figure 4 A schematic diagram of the change trend of the color gamut that can be obtained by an LED chip provided by an embodiment of the present invention in the CIE color coordinates;

[0022] Figure 5 A schematic diagram of the display color gamuts of two displays provided by an embodiment of the present invention and the NTSC and BT.2020 standard color gamuts;

[0023] Figure 6 Another schematic structural diagram of a white light package using a blue-green dual-peak single crystal chip provided by an embodiment of the present invention;

[0024] Figure 7 Another schematic structural diagram of a white light package using a blue-green dual-peak single crystal chip provided by an embodiment of the present invention;

[0025] Figure 8 Another schematic structural diagram of a white light package using a blue-green dual-peak single crystal chip provided by an embodiment of the present invention;

[0026] Figure 9 A schematic structural diagram of an LED chip after NCSP packaging provided by an embodiment of the present invention;

[0027] Figure 10 Another schematic structural diagram of an LED chip after NCSP packaging provided by an embodiment of the present invention;

[0028] Figure 11 Another schematic structural diagram of an LED chip after NCSP packaging provided by an embodiment of the present invention;

[0029] Figure 12Schematic diagram of the structure of the LED chip provided by the embodiment of the present utility model through flip-chip bonding and SMD packaging;

[0030] Figure 13 Schematic diagram of the structure of the LED chip provided by the embodiment of the present utility model after flip-chip bonding and NCSP packaging;

[0031] Figure 14 Schematic diagram of the structure of the package body sealed on the circuit board through a lens;

[0032] Figure 15 Schematic diagram of a structure of the blue-green dual-peak single-crystal chip provided by the embodiment of the present utility model;

[0033] Figure 16 For the embodiment of the present utility model Figure 15 Schematic diagram of the structure of the blue-green dual-peak single-crystal chip after SMD packaging.

[0034] Among them, each reference numeral in the figure:

[0035] 1. Substrate;

[0036] 2. Blue-green dual-peak single-crystal chip; 21. Blue-light quantum well layer; 22. Green-light conversion layer; 23. n-type gallium nitride layer; 24. Isolation layer; 25. Through hole; 26. Insulating layer;

[0037] 3. Red-light conversion layer; 31. Perovskite quantum dots;

[0038] 4. p-type gallium nitride layer;

[0039] 5. n-type electrode;

[0040] 6. p-type electrode;

[0041] 7. Lens;

[0042] 8. Circuit board;

[0043] 9. First bracket; 91. Second bracket; 92. Gap; 93. Placing groove; 94. Gold wire; 95. Silicone layer; 96. Upper silicone; 97. Lower silicone; 98. Substrate; 99. Through hole; 90. Reflective layer;

[0044] 10. Package body. Detailed implementation manners

[0045] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0046] It should be noted that when a component is referred to as "fixed to" or "disposed on" another component, it can be directly or indirectly located on that other component. When a component is referred to as "connected to" another component, it can be directly or indirectly connected to that other component. The orientations or positions indicated by the terms "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positions shown in the drawings, and are only for convenience of description and should not be construed as limitations on the technical solution of the present invention. The terms "first" and "second" are only for convenience of description and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of technical features. The meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0047] An embodiment of the present invention provides a white light package using a blue-green dual-peak single crystal chip. The following describes the white light package using a blue-green dual-peak single crystal chip according to the embodiments of the present invention with reference to the drawings.

[0048] Please refer to Figure 1 , Figure 1 , which shows a schematic structural diagram of the white light package using a blue-green dual-peak single crystal chip of the present application, including a packaging structure and an LED chip disposed in the packaging structure. After the LED chip is excited, the white light package emits white light.

[0049] Specifically, referring to Figure 1 and Figure 2 , the LED chip includes a substrate 1, a blue-green dual-peak single crystal chip 2, and a red light conversion layer 3 stacked in sequence from bottom to top. The blue-green dual-peak single crystal chip 2 includes an electroluminescent blue light quantum well layer and a photoluminescent green light conversion layer. Specifically, by epitaxial growth on a gallium nitride layer, a blue light quantum well layer 21 and a green light conversion layer 22 are formed to constitute the blue-green dual-peak single crystal chip 2 of a single crystal structure. The red light conversion layer 3 contains a red light wavelength conversion material including perovskite quantum dots 31.

[0050] From the perspective of product implementation, by controlling the growth conditions of the quantum well layer, the blue light quantum well layer 21 and the green light conversion layer 22 are directly integrated on the gallium nitride layer, and then the red light conversion layer 3 is stacked on the green light conversion layer 22. The red light wavelength conversion material in the red light conversion layer 3 is pumped by the blue light quantum well layer 21 and the green light conversion layer 22 to emit red light, obtaining a red light emitting unit, thereby integrating RGB pixel units to form white light conversion to achieve full-color backlight display.

[0051] Among them, in the present application, a blue-green dual-peak single-crystal chip 2 with an integrated structure is formed by directly growing a blue-light quantum well layer 21 that emits blue light electro-optically and a green-light conversion layer 22 that emits green light photo-optically on a gallium nitride layer. The blue-green dual-peak single-crystal chip 2 can simultaneously emit blue light and green light with blue-green dual peaks when the blue-light quantum well layer 21 is driven by current. Compared with the conventional method of separately setting a blue-light chip and a green-light chip, the problem of integrated transfer of micro LEDs of multiple colors is avoided, the manufacturing process is simple and easy to produce. Moreover, when used as a backlight source, the spatial distribution of the blue-light quantum well layer 21 and the green-light conversion layer 22 is uniform, greatly reducing the risk of blue and green spots. During use, as the LED chip does not produce color spot shift with temperature change, the probability of color drift is reduced, thereby improving the color gamut of the LED chip.

[0052] Meanwhile, a red-light wavelength conversion material including perovskite quantum dots 31 is provided in the red-light conversion layer 3 of the present application. The blue and green light emitted by the blue-green dual-peak single-crystal chip 2 is directed towards the red-light conversion layer 3 to pump the red-light wavelength conversion material, causing the red-light wavelength conversion material to emit red light. Using the perovskite quantum dot 31 material as the color conversion layer, the absorption coefficient of the perovskite material is on the order of 10 5 cm -1 magnitude, and a backlight source with an extremely high display color gamut can be obtained. The color gamut can reach more than 100% of NTSC, far greater than the color gamut that can be achieved by the conventional red-light phosphor layer, further enhancing the display color gamut of the LED chip.

[0053] In some embodiments, based on the red-light conversion layer 3, by combining other perovskite quantum dots 31 with other red-light quantum dots, a backlight source with a high color gamut is successfully obtained under the excitation of blue and green light.

[0054] Exemplarily, a red-light conversion layer 3 is formed by combining perovskite quantum dots 31 with cadmium sulfide quantum dots, and its display color gamut can reach 121% of the NTSC color gamut. The structure and performance of the prepared backlight source are as Figure 4 shown.

[0055] Of course, in addition to cadmium sulfide quantum dots, the red-light conversion layer 3 may further contain a red-light wavelength conversion material of any one or a combination of cadmium selenide quantum dots, indium phosphide quantum dots, lead selenide quantum dots, mercury antimonide quantum dots, and lead sulfide quantum dots.

[0056] Using perovskite quantum dots 31 as the main red-light wavelength conversion material and combining other red-light quantum dots as the secondary red-light wavelength conversion material to form a composite quantum dot material has achieved a certain degree of improvement in terms of manufacturing cost and the display color gamut that can be obtained, achieving the effect of reducing costs and increasing efficiency.

[0057] Furthermore, considering the fine device structure inside the LED chip, an inkjet printing strategy is adopted to pattern the perovskite material so that it can be effectively integrated with the blue light quantum well layer 21 and the green light conversion layer 22 at the pixel level to achieve full-color display. Specifically, an inkjet printing combined with ultraviolet light polymerization strategy is adopted to prepare a perovskite quantum dot 31 thin film layer with a micron level. Under the irradiation of UV light (365 nm), whether it is the macroscopic thin film layer or the thin film layer inside the Bank pixel microscopically, it shows good luminescence uniformity. There is no phenomenon of dark in the middle area and bright at the edge inside the Bank pixel. Through the inkjet printing combined with ultraviolet light polymerization strategy, the generation of the coffee ring phenomenon is effectively suppressed, making its luminescence characteristics and color conversion effect stable, and the display effect is more excellent.

[0058] Furthermore, referring to Figure 1 and Figure 2 , the red light conversion layer 3 is a thin film layer stacked on the blue-green double-peak single crystal chip 2. The thickness of the perovskite quantum dot material or its mixture with the carrier in the red light conversion layer is 10 - 250 microns. More specifically, it is stacked on the green light conversion layer 22. To avoid the risk of crosstalk between adjacent pixels, it is simulated and verified using LightTool software. By adjusting the distance between the blue-green double-peak single crystal chip 2 and the red light conversion layer 3, the crosstalk phenomenon is simulated. When the distance is set to 65 microns, the simulation results confirm that the crosstalk between adjacent pixels is obvious at this time, and there is an overlap in the luminous intensity distribution of adjacent pixels.

[0059] When the distance is reduced to 10 microns, the crosstalk phenomenon is significantly weakened. At this time, the luminous intensity distribution of adjacent pixels already has obvious boundaries. Therefore, in this application, the thickness of the perovskite quantum dot 31 in the red light conversion layer 3 is set to 10 - 65 microns to reduce the crosstalk risk.

[0060] Preferably, the thickness of the perovskite quantum dot 31 in the red light conversion layer 3 is set to 10 - 55 microns to further reduce the crosstalk risk.

[0061] In some embodiments, the red light conversion layer 3 is stacked and covered on the blue-green double-peak single crystal chip 2 by evaporation or inkjet printing. More specifically, it is covered on the green light conversion layer 22.

[0062] In some embodiments, the blue-green double-peak single crystal chip 2 includes a gallium nitride layer. The gallium nitride layer includes an n-type gallium nitride layer 23 and a p-type gallium nitride layer 4. The blue-green double-peak single crystal chip 2 grows InxGa1-xN / GaN quantum well layers on both the polar and non-polar surfaces of the patterned n-type gallium nitride layer 23.

[0063] The InxGa1-xN / GaN quantum well layer grown on the polar surface serves as the green light conversion layer 22 that emits green light under optical excitation, with the x value ranging from 0.15 to 0.35. The InxGa1-xN / GaN quantum well layer grown on the non-polar surface serves as the blue light quantum well layer 21 that emits blue light under electrical excitation, with the x value ranging from 0.15 to 0.35.

[0064] Specifically, the thicknesses of the well layer and the barrier layer of the green light conversion layer 22 are 2 - 9 nm and 9 - 20 nm respectively, and the thicknesses of the well layer and the barrier layer of the blue light quantum well layer 21 are 1 - 6 nm and 9 - 20 nm respectively.

[0065] At the material growth level, by simultaneously growing the quantum well layer (InxGa1-xN / GaN, x = 0.15 - 0.35) on the polar and non-polar surfaces of the n-type gallium nitride layer 23, the quantum well layer epitaxially grown on the polar surface emits green light after being pumped by blue light and serves as the green light conversion layer 22 that emits green light under optical excitation. For the quantum well layer epitaxially grown on the non-polar surface, its growth rate is lower than that of the polar surface, and the well width of the epitaxial quantum well becomes narrower, resulting in a blue shift of the emission wavelength after electrification, and it can emit blue light, serving as the blue light quantum well layer 21 that emits blue light under electrical excitation. By controlling the growth conditions of the quantum well active layer, the blue light quantum well layer 21 and the green light conversion layer 22 are directly integrated.

[0066] Furthermore, referring to Figure 1 and Figure 2 , the blue light quantum well layer 21 and the red light conversion layer 3 continue to grow epitaxially to form a p-type gallium nitride layer 4. An n-type electrode 5 is deposited on the n-type gallium nitride layer 23, and a p-type electrode 6 is deposited on the p-type gallium nitride layer 4.

[0067] Among them, referring to Figure 1 , the n-type electrode 5 deposited on the n-type gallium nitride layer 23 is used for electrical connection with the circuit board, and the p-type electrode 6 deposited on the p-type gallium nitride layer 4 epitaxially grown on the blue light quantum well layer 21 is used for electrical connection with the circuit board, so that the circuit board supplies power to the blue light quantum well layer 21 that emits light under electrical excitation.

[0068] It should be noted that in this application, the blue light quantum well layer 21 is electroluminescent, the green light conversion layer 22 and the red light conversion layer 3 are photoluminescent. The complete color conversion uses the blue light quantum well layer 21 as the excitation source. After current is applied to the blue light quantum well layer 21, blue light is emitted. When the blue light enters the green light conversion layer 22, a part of the blue light excites the green light conversion layer 22 to emit green light, and a part of the blue light passes through the green light conversion layer 22 and irradiates into the red light conversion layer 3, pumping the red light wavelength conversion material including the perovskite quantum dots 31 in the red light conversion layer 3 to emit red light. By adopting the color conversion strategy, the required green light and red light emissions are obtained, which are combined with the blue light emitted by the blue light quantum well layer 21 to produce white light, realizing full-color backlight display. It has the potential to achieve higher luminous efficiency and better color gamut performance at lower cost, and has better reliability and durability superior to traditional phosphor conversion technology.

[0069] Among them, this LED chip includes a regular short-wavelength region for electroluminescent (EL) emission and one or more native photoluminescent (PL) color conversion regions. The shorter-wavelength electroluminescent region (blue light quantum well layer 21) is responsible for optimizing carrier injection and recombination efficiency, while the longer-wavelength photoluminescent region (green light conversion layer 22) is responsible for efficient color conversion. Compared with traditional LEDs, this LED chip structure exhibits higher efficiency, less light decay, less blue shift, and a narrower full width at half maximum (FWHM) of the spectrum.

[0070] Furthermore, the blue light quantum well layer 21 for photoluminescence is composed of indium gallium nitride material or a composite material with indium gallium nitride, and the green light conversion layer 22 for photoluminescence is composed of any one of gallium aluminum phosphide, indium gallium nitride / gallium nitride, gallium phosphide, aluminum indium gallium phosphide, gallium carbide or a combination thereof.

[0071] In the above embodiment, the blue light quantum well layer 21 is located between the substrate and the green light conversion layer 22. In some embodiments, refer to Figure 15 , the green light conversion layer 22 is disposed between the substrate and the blue light quantum well layer 21. Specifically, from the substrate upwards are the green light conversion layer 22, the blue light quantum well layer 21, and the red light conversion layer 3. Among them, the blue light quantum well layer 21 is the electroluminescent region, and both the green light conversion layer 22 and the red light conversion layer 3 are photoluminescent regions. The complete color conversion uses the blue light quantum well layer 21 as the excitation source. After current is applied to the blue light quantum well layer 21, blue light is emitted. A part of the blue light enters the green light conversion layer 22 and excites the green light conversion layer 22 to emit green light, and the other part of the blue light irradiates into the red light conversion layer 3, pumping the red light wavelength conversion material including the perovskite quantum dots 31 in the red light conversion layer 3 to emit red light. By adopting the color conversion strategy, the required green light and red light emissions are obtained, which are combined with the blue light emitted by the blue light quantum well layer 21 to produce white light, realizing full-color backlight display.

[0072] Furthermore, continue to refer toFigure 15 The blue-green dual-peak single-crystal chip 2 includes a gallium nitride layer. The gallium nitride layer includes an n-type gallium nitride layer 23 and a p-type gallium nitride layer 4. An InxGa1-xN / GaN quantum well layer is grown on the polar surface of the patterned n-type gallium nitride layer 23 as a green light conversion layer 22 for photoluminescence of green light. The value of x is 0.15 - 0.35. The non-polar surface of the n-type gallium nitride layer 23 is disposed on the substrate 1. Then, an isolation layer 24 is disposed on the green light conversion layer 22, and an InxGa1-xN / GaN quantum well layer is grown on the isolation layer as a blue light quantum well layer 21 for electroluminescence of blue light. The value of x is 0.15 - 0.35. Then, a p-type gallium nitride layer 4 is epitaxially grown on the blue light quantum well layer 21 to form the blue-green dual-peak single-crystal chip 2. Specifically, the thicknesses of the well layer and the barrier layer of the green light conversion layer 22 are 2 - 9 nanometers and 9 - 20 nanometers respectively, and the thicknesses of the well layer and the barrier layer of the blue light quantum well layer 21 are 1 - 6 nanometers and 9 - 20 nanometers respectively.

[0073] Among them, continuing to refer to Figure 15 An n-type electrode 5 is deposited on the n-type gallium nitride layer 23, and a p-type electrode 6 is deposited on the p-type gallium nitride layer 4. The n-type electrode 5 deposited on the n-type gallium nitride layer 23 is used for electrical connection with the circuit board 8. Through holes 25 are etched in the isolation layer 24 and the green light conversion layer 22. Both ends of the through holes 25 are respectively connected to the n-type gallium nitride layer 23 and the blue light quantum well layer 21. The n-type gallium nitride layer 23 and the blue light quantum well layer 21 are electrically connected by a wire. An insulating layer 26 is disposed on the inner wall of the through hole 25 to prevent the wire between the n-type gallium nitride layer 23 and the blue light quantum well layer 21 from being energized with other structural layers. The p-type electrode 6 deposited on the p-type gallium nitride layer 4 epitaxially grown on the blue light quantum well layer 21 is used for electrical connection with the circuit board 8. Thus, the circuit board 8 supplies power to the blue light quantum well layer 21 for electroluminescence.

[0074] Refer to Figure 16 is Figure 15 a schematic structural diagram after encapsulation of the blue-green dual-peak single-crystal chip 2 in Figure 15 Of course, other encapsulation methods can also be used to encapsulate the blue-green dual-peak single-crystal chip 2 in

[0075] In some embodiments, referring to Figure 1 and Figure 14 The encapsulation structure includes a lens 7 and a circuit board 8. The lens 7 encapsulates the LED chip on the circuit board 8 by the SMT encapsulation method. Specifically, after the LED chip is soldered on the circuit board 8, the LED chip is sealed on the circuit board 8 by the lens 7.

[0076] The display performance of the finally obtained LED chip was characterized. The color performance of the LED chip of the present application is very pure, and the color performance is better than that of the conventional LED chip. Refer toFigure 5 , for a full-color display based on a conventional LED chip, its display color gamut can only reach 99% NTSC, while for a full-color display based on the LED chip of the present application, the display color gamut is as high as 129% NTSC. In addition, even if only the red light is converted by the red conversion layer having perovskite quantum dots 31 and the remaining blue and green lights still use conventional LED chips, the obtained display color gamut is also as high as 126% NTSC.

[0077] Among them, when encapsulating the LED chip in the SMT encapsulation method, the method shown in Figure 6 can be adopted. Among them, when preparing the LED chip, the step of preparing the red conversion layer 3 is reduced. During SMT encapsulation, a silica gel layer is provided on the surface of the LED chip. By providing perovskite quantum dots 31 or other red light quantum dot materials in the silica gel layer, the red conversion layer is formed. Specifically, a bracket is provided on the circuit board. The bracket includes a first bracket 9 and a second bracket 91 that are butt-jointed. A gap 92 that penetrates to the circuit board 8 is formed between the butt-jointed first bracket 9 and second bracket 91. And, a bowl-shaped placement groove 93 is formed after the butt-jointed first bracket 9 and second bracket 91. A gold wire 94 is provided at the bottom of the placement groove 93. The gold wire 94 is connected to the circuit board 8 through the gap 92. The LED chip is provided at the bottom of the placement groove 93. The n-type electrode 5 and the p-type electrode 6 are connected to the gold wire 94 to be electrically connected to the circuit board 8. The gap 92 is filled and sealed with a silica gel material, and the first bracket 9 and the second bracket 91 are bonded into an integral structure. The top region of the placement groove 93 is filled with a silica gel layer 95, and red light quantum dot materials or red light phosphors are uniformly filled in the silica gel layer 95.

[0078] Of course, the silica gel layer 95 can also be divided into an upper silica gel 96 and a lower silica gel 97, as shown in Figure 7 . Red light quantum dot materials or red light phosphors are uniformly filled in the upper silica gel 96, and diffusion powder is uniformly filled in the lower silica gel 97; it can also be as shown in Figure 8 . Diffusion powder is uniformly filled in the upper silica gel 96, and red light quantum dot materials or red light phosphors are uniformly filled in the lower silica gel 97.

[0079] Further, in addition to the SMT encapsulation method, the NCSP encapsulation method can also be adopted to encapsulate the LED chip. Similarly, when preparing the LED chip, the step of preparing the red conversion layer 3 is reduced. During NCSP encapsulation, a silica gel layer is provided on the surface of the LED chip. By uniformly filling perovskite quantum dots 31 or other red light quantum dot materials in the silica gel layer, the red conversion layer is formed. Specifically, refer to Figure 9, a substrate 98 is disposed on the circuit board 8, a through hole 99 penetrating up and down is disposed on the substrate 98, and the through hole 99 is filled with a conductive material, which may be copper. Gold wires 95 connected to the conductive material are provided on both the upper and lower surfaces of the substrate. The LED chip is disposed on the substrate 98. The n-type electrode 5 and the p-type electrode 6 are connected to the gold wire 94 on the upper surface of the substrate 98, and the gold wire 94 on the lower surface of the substrate 98 is connected to the circuit board 8 so that the LED chip is electrically connected to the circuit board 8. A silica gel layer 95 is disposed above the substrate 98, and the silica gel layer 95 hermetically wraps the LED chip on the substrate 98. The silica gel layer 95 is uniformly filled with red light quantum dot materials or red light fluorescent powder.

[0080] Further, as Figure 11 shown, a reflective layer 90 is disposed above the silica gel layer 95. The reflective layer 90 is made of transparent silica gel, and the reflective layer 90 is uniformly filled with reflective powder.

[0081] Of course, as Figure 10 shown, the reflective layer 90 can also be disposed on the side of the silica gel layer 95, and the reflective layer 90 is uniformly filled with reflective powder.

[0082] In some embodiments, the LED chip can also be packaged by means of flip chip combined with SMT packaging or NCSP packaging. Refer to Figure 12 , which is a schematic diagram of a flip LED chip packaged on the circuit board 8 by means of SMT packaging. Refer to Figure 13 , which is a schematic diagram of a flip LED chip packaged on the circuit board 8 by means of NCSP packaging. The methods of SMT packaging and NCSP packaging have been described in the above embodiments and will not be elaborated here. Moreover, the installation method of the flip chip is that the front side of the LED chip faces downwards towards the substrate, without wire bonding, forming the shortest circuit, reducing resistance, using metal balls for connection, reducing the packaging size, and improving the electrical performance. This is a mature connection technology in the art and will not be elaborated here.

[0083] In some embodiments, refer to Figure 14 , the LED chip is packaged by means of SMT packaging or NCSP packaging to form a package 10. The package 10 is located on the circuit board 8 and is sealed on the circuit board 8 by a lens 7. Among them, the lens 7 covers the package 10.

[0084] The embodiment of the present invention also provides a preparation method for white light packaging, which is applied to the white light packaging using a blue-green dual-peak single crystal chip in the above embodiments. Refer to Figure 3 , and includes the following steps:

[0085] Step 1: Grow an n-type gallium nitride layer 23 on the surface of the substrate 1, perform photolithography on the n-type gallium nitride layer 23 to obtain a patterned n-type gallium nitride layer 23, and form micron grooves with a depth of 500 - 2500 nanometers, a length of 5 - 50 microns, a width of 0.5 - 10 microns, and a pitch of 20 - 200 microns;

[0086] Step 2: Use the MOCVD method to simultaneously grow quantum well layers (InGaN / GaN quantum well structure) on the polar and non-polar surfaces of the patterned n-type gallium nitride layer 23 to obtain a blue light quantum well layer 21 and a green light conversion layer 22, forming a blue-green dual-peak single crystal chip 2 with a single crystal structure;

[0087] Step 3: Form a red light conversion layer 3 on the blue-green dual-peak single crystal chip 2 by means of dispensing, injection molding, evaporation coating, or inkjet printing.

[0088] Furthermore, the following steps are also included:

[0089] Step 4: Use the MOCVD method to continue epitaxially grow a p-type gallium nitride layer 4 on the blue light quantum well layer 21 and the red light conversion layer 3;

[0090] Step 5: Use ICP-RIE etching technology to etch the LED mesa. On one side of the LED chip, etch from the top of the p-type gallium nitride layer 4 above the red light conversion layer 3 to the upper surface of the p-type gallium nitride layer 4 below the blue light quantum well layer 21. On the other side of the LED chip, etch from the top of the p-type gallium nitride layer 4 above the red light conversion layer 3 to the upper surface of the n-type gallium nitride layer 23. Use the PECVD method to deposit a silicon dioxide insulating layer on the top of the p-type gallium nitride layer 4, the top of the n-type gallium nitride layer 23, and their vertical connection surfaces, and open holes on the top of the n-type gallium nitride layer 23 (the opening is used to form an n-type electrode 5) and on the top of the p-type gallium nitride layer 4 (the opening is used to form a p-type electrode 6). Use physical vapor deposition magnetron sputtering technology to deposit an n-type electrode 5 on the n-type gallium nitride layer 23 and a p-type electrode 6 on the p-type gallium nitride layer 4. Finally, package the LED chip through SMT packaging to obtain an SMD packaging structure, and package it onto the circuit board 8. After packaging the LED chip, the n-type electrode 5 at the n-type gallium nitride layer 23 is electrically connected to the circuit board, and the p-type electrode 6 on the upper surface of the p-type gallium nitride layer 4 below the blue light quantum well layer 21 is electrically connected to the circuit board.

[0091] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A white light package using a blue-green dual-peak single crystal chip, characterized in that, It includes a packaging structure and an LED chip disposed within the packaging structure; The LED chip includes a substrate, a blue-green dual-peak single-crystal chip, and a red light conversion layer stacked in sequence from bottom to top. The blue-green dual-peak single-crystal chip includes an electroluminescent blue light quantum well layer and a photoluminescent green light conversion layer. The red light conversion layer contains a red light wavelength conversion material including perovskite quantum dots.

2. The white light package using a blue-green dual-peak single crystal chip according to claim 1, wherein The red light conversion layer further contains a red light wavelength conversion material which is any one or a combination of cadmium selenide quantum dots, indium phosphide quantum dots, and cadmium sulfide quantum dots.

3. The white light package using a blue-green dual-peak single crystal chip according to claim 1, characterized in that The red light conversion layer is a thin film layer stacked on the blue-green dual-peak single-crystal chip. The thickness of the perovskite quantum dot material or its mixture with a carrier in the red light conversion layer is 10 - 250 microns.

4. The white light package using a blue-green dual-peak single crystal chip according to claim 1, characterized in that, The blue and green light emitted by the blue-green dual-peak single-crystal chip is directed towards the red light conversion layer to pump the red light wavelength conversion material, causing the red light wavelength conversion material to emit red light.

5. The white light package using a blue-green dual-peak single crystal chip according to claim 1, characterized in that, The red light conversion layer is stacked and covered on the blue-green dual-peak single-crystal chip by means of dispensing, injection molding, evaporation coating, or inkjet printing.

6. The white light package using a blue-green dual-peak single crystal chip according to claim 1, wherein The blue-green dual-peak single-crystal chip includes a gallium nitride layer. The gallium nitride layer includes an n-type gallium nitride layer and a p-type gallium nitride layer. InxGa1-xN / GaN quantum well layers are grown on both the polar and non-polar surfaces of the n-type gallium nitride layer.

7. The white light package using a blue-green dual-peak single crystal chip according to claim 1, wherein The packaging structure includes a lens and a circuit board. The lens packages the LED chip on the circuit board by means of SMT packaging or COB packaging.

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