Afterglow powder packaging method of LED device and afterglow powder packaged LED device

Abstract

The invention relates to the field of LED packaging, in particular to an afterglow powder packaging method of an LED device and the afterglow powder packaged LED device. According to the afterglow powder packaging method of the LED device, rare earth doped afterglow powder, LED fluorescent powder and LED packaging glue are made into a light function membrane with an afterglow light-emitting function, and the obtained membrane is packaged on an LED chip in a core-separating packaging mode, namely, the obtained membrane is fixed above the LED chip at a certain interval. The afterglow powder can be isolated from a heat source of the LED chip, the temperature of the afterglow powder is remarkably reduced, the influence of the temperature on the performance of the fluorescent powder is reduced, the lighting effect is improved, the afterglow time is prolonged, the optical loss of the afterglow powder is reduced, more uniform light distribution is achieved, and the problems that an existing packaging method is high in cost, complex in technology, large in limitation and the like are solved. The overall lighting effect of the LED device packaged by the afterglow powder is improved, and the characteristic of compensating for stroboflash is taken into account.

Description

Technical Field

[0001] The invention relates to the field of LED packaging, in particular to an afterglow powder packaging method for an LED device and an afterglow powder packaged LED device. Background Art

[0002] Afterglow powder is a kind of phosphor with the ability to store light. This kind of phosphor can still emit light when not excited, so it is also called luminous powder. LED devices are typical semiconductor devices that can only emit light when powered in one direction. The general mains power is 50Hz AC, so it faces the problem of flicker. The traditional LED flicker problem usually needs to be solved by adding capacitor filtering or using more complex power drive circuits, which will increase costs and system complexity. The packaging design using long afterglow phosphors can directly use the afterglow characteristics of the material to smooth brightness changes, reduce or avoid reliance on complex circuit design, and reduce costs and device complexity. Therefore, it is of great advantage to use the light storage function of afterglow powder to compensate for the LED flicker generated during the AC conversion process.

[0003] First of all, using afterglow powder for LED device packaging will have a good price advantage. In low-cost LED systems, flicker is particularly obvious because these systems often use simple rectifiers and drive circuits. By adding long afterglow phosphors, the luminous performance can be significantly improved without significantly increasing the complexity of the circuit, so that low-cost LED systems can also provide high-quality lighting. On the other hand, because long afterglow phosphors can continue to emit light for a long time, the light output will be more stable and reduce the phenomenon of sudden changes in brightness. Compared with the brightness drop of traditional LEDs at the trough of the rectifier output, the afterglow performance can fill the brightness gap and produce a more uniform lighting effect.

[0004] However, the use of afterglow powder in LED packaging also faces a huge challenge, namely how to improve the luminous efficiency. On the one hand, the intensity of photoluminescence of afterglow powder is relatively low compared with traditional LED phosphors because it needs to ensure the ability to store light. On the other hand, in traditional LED packaging, the phosphor is directly coated on the surface of the chip, which is affected by the high temperature of the chip, resulting in a decrease in the luminous efficiency of the phosphor and a weakening of the afterglow performance. In addition, the phosphor is close to the LED chip. Since the LED generates heat when working, the phosphor will be subjected to greater heat, resulting in a decrease in performance and even accelerated material aging. In addition, the phosphor is close to the chip and is easily affected by reflected and reabsorbed light, resulting in optical loss.

[0005] At present, the main methods to improve the light efficiency are to improve the chip efficiency. The use of efficient semiconductor materials, such as gallium nitride (GaN) and indium gallium nitride (InGaN), can improve the internal quantum efficiency of LED chips. These materials have high luminous efficiency in the blue and green light bands and are suitable for the manufacture of high-efficiency LED chips. By introducing microstructures (such as roughened surfaces, Bragg reflectors, microlens arrays, etc.) on the surface of LED chips, the total reflection of light inside the chip can be reduced, the light extraction efficiency can be increased, and the overall light efficiency can be improved. Choosing an efficient LED drive circuit can minimize power loss and improve light efficiency. In particular, choosing a constant current drive circuit can ensure that the LED operates under a stable current and avoid efficiency loss caused by current fluctuations. The biggest problems with these methods are increased costs, technical complexity, and limitations in practical applications.

[0006] Therefore, how to improve the overall luminous efficacy of afterglow powder packaged LED devices with low cost, simple method and great universality, while compensating for the flicker characteristics has become a huge problem. Summary of the invention

[0007] In view of this, the technical problem to be solved by the present invention is to provide an afterglow powder packaging method for LED devices and an afterglow powder packaged LED device. The packaging method provided by the present invention can achieve high overall luminous efficiency of the afterglow powder packaged LED device.

[0008] The present invention provides a method for packaging afterglow powder of an LED device, comprising the following steps:

[0009] The rare earth doped afterglow powder, LED phosphor and LED packaging adhesive are made into a film, and the obtained film is fixed on the LED chip at a distance of 100 μm to 5 cm;

[0010] The rare earth doped afterglow powder is selected from one or more of rare earth doped sulfide long afterglow luminescent materials, rare earth doped aluminate long afterglow luminescent materials, rare earth doped silicate long afterglow luminescent materials, rare earth doped titanate long afterglow luminescent materials or rare earth doped nitride long afterglow luminescent materials;

[0011] The LED phosphor is selected from one or more of rare earth doped YAG, rare earth doped LuAG, rare earth doped CaAlSiN3 or rare earth doped Sr2Si5N8.

[0012] The inventor of the present application creatively discovered that the rare earth doped afterglow powder, LED fluorescent powder and LED packaging glue are made into a diaphragm, and the obtained diaphragm is a light functional diaphragm with afterglow luminescence function. The obtained diaphragm is encapsulated on the LED chip by the off-core packaging method, that is, the obtained diaphragm is fixed above the LED chip at a certain distance, which can isolate the afterglow powder from the heat source of the LED chip, significantly reduce the temperature of the afterglow powder, reduce the influence of temperature on the performance of the afterglow powder, improve the light efficiency and extend the afterglow time. At the same time, fixing the afterglow powder away from the LED chip helps to reduce the optical loss of the afterglow powder and helps to avoid the high-brightness light spot directly generated by the chip; after the light passes through the afterglow powder layer away from the chip, a more uniform light distribution can be achieved, reducing the light spot and color difference problems. In addition, since the afterglow performance of the rare earth doped afterglow powder is closely related to the temperature, the off-core packaging structure can be used to adjust the temperature of the afterglow powder and thus adjust the afterglow time of the LED device, and better compensate for the stroboscopic light caused by the periodic conversion of the alternating current.

[0013] The afterglow powder of the present invention is preferably one or more of SrAl2O4:Eu, Dy, SrS:Eu, CaS:Eu or Sr2MgSi2O7:Eu; the LED phosphor of the present invention is preferably selected from Y3Al5O 12 :Ce, 1113 nitride phosphor or 258 nitride red fluorescent phosphor, more preferably 1113 nitride phosphor.

[0014] Preferably, the membrane is fixed above the LED chip at a spacing of 500 μm to 2 cm. More preferably, the membrane is fixed above the LED chip at a spacing of 500 μm to 5 mm. Even more preferably, the membrane is fixed above the LED chip at a spacing of 500 μm to 2 mm. Most preferably, the membrane is fixed above the LED chip at a spacing of 1 mm.

[0015] The present invention makes a diaphragm from rare earth doped afterglow powder, LED fluorescent powder and LED packaging glue, specifically, the afterglow powder, LED fluorescent powder and LED packaging glue are coated on a substrate or injection molded, and cured to obtain a diaphragm. More specifically, the afterglow powder, LED fluorescent powder and LED packaging glue are mixed evenly, defoamed by standing or shaking or other methods, and then the evenly mixed material is coated on a flat substrate, or the evenly mixed material is filled into a mold with a certain shape, and placed in an oven and set for a certain time and temperature to cure to obtain a diaphragm. The coating method of the present invention includes spin coating, scraping or brushing. The curing temperature of the present invention is 50°C~80°C, and the curing time is 1 h~5h.

[0016] The present invention fixes the diaphragm above the LED chip, and the diaphragm can be fixed above the LED chip by a bracket; specifically, brackets are arranged around the LED chip, and the diaphragm is fixed on the brackets, so that the diaphragm is fixed above the LED chip. The present invention can also arrange a transparent diaphragm between the diaphragm and the LED chip, and fix the diaphragm above the LED chip by the transparent diaphragm, and control the distance between the diaphragm and the LED chip by controlling the thickness of the transparent diaphragm.

[0017] The LED packaging adhesive of the present invention is selected from one or more of epoxy resin, organic silicone, polyurethane adhesive or organic adhesive. In some embodiments of the present invention, the LED packaging adhesive is Leining LN-103A / B, Dow Corning DC184, Dow Corning OE-7662A / B, Dow Corning OE-6636A / B, Dow Corning CF-5970A / B, Kraft K-5312W or Kraft Hasuncast RTVS603.

[0018] The LED chip of the present invention is selected from a gallium nitride LED chip, an aluminum phosphide LED chip or a silicon carbide LED chip. The emission wavelength of the LED chip of the present invention is 420 nm to 470 nm. Preferably, the LED chip is a gallium nitride blue LED chip. In some embodiments of the present invention, the LED chip is a gallium nitride blue LED chip with an emission wavelength of 420 nm to 470 nm.

[0019] The present invention also provides an afterglow powder packaged LED device obtained by applying the afterglow powder packaging method described in any of the above technical solutions. The afterglow powder packaged LED device provided by the present invention is obtained by packaging a film made of materials containing afterglow powder and phosphor on an LED chip by an off-core packaging method, and has high light efficiency.

[0020] The present invention provides an afterglow powder packaging method for an LED device and an afterglow powder packaging LED device. The afterglow powder packaging method for an LED device provided by the present invention comprises the following steps: preparing a diaphragm with rare earth-doped afterglow powder, LED fluorescent powder and LED packaging glue, and fixing the obtained diaphragm above an LED chip at a spacing of 100 μm to 5 cm; the rare earth-doped afterglow powder is selected from one or more of rare earth-doped sulfide long afterglow luminescent materials, rare earth-doped aluminate long afterglow luminescent materials, rare earth-doped silicate long afterglow luminescent materials, rare earth-doped titanate long afterglow luminescent materials or rare earth-doped nitride long afterglow luminescent materials; the LED fluorescent powder is selected from Y3A l5 O 12 、Lu3Al5O 12One or more of phosphor, CaAlSiN3 or Sr2Si5N8. The present invention realizes the packaging of afterglow powder on LED chip by making rare earth doped afterglow powder, LED phosphor and LED packaging glue into a light functional film with afterglow luminescence function and off-core packaging, which not only solves the problems of high cost, complex technology and great limitations of the existing packaging method, but also improves the overall light efficiency of afterglow powder packaged LED devices, and takes into account the characteristics of compensating for stroboscopic. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of an off-core packaged LED device with an afterglow light functional film;

[0022] Figure 2 This is a photofunctional film diagram of Example 1;

[0023] Figure 3 This is a transparent film image without phosphor in Example 1;

[0024] Figure 4 This is a diagram of an off-core packaged LED device of Example 1;

[0025] Figure 5 This is a photo functional film prepared in Example 4;

[0026] Figure 6 This is a diagram of an off-core packaged LED device of Example 5;

[0027] Figure 7 This is a schematic diagram of an LED device using a bracket off-core package to encapsulate an afterglow light functional film in Example 6. DETAILED DESCRIPTION

[0028] The present invention discloses an afterglow powder packaging method for LED devices and an afterglow powder packaged LED device. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve it. It is particularly important to point out that all similar replacements and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The method and application of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the method and application of this article without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0029] The present invention utilizes off-core packaging technology to improve the light efficiency of afterglow LED devices. Off-core packaging is to fix the light functional film at a certain distance from the chip. Specifically, a special bracket or a transparent film can be used to fix the light functional film at a certain distance from the chip, such as Figure 1 As shown, Figure 1 Schematic diagram of off-core packaged LED device with afterglow light functional membrane.

[0030] The LED chip used in the present invention is a gallium nitride chip with an emission wavelength of 425 nm.

[0031] The present invention will be further described below in conjunction with embodiments:

[0032] Example 1

[0033] Using SrAl2O4:Eu 2+ ,Dy 3+ Afterglow powder and SrS:Eu 2+ Afterglow powder and LED packaging glue are used to prepare a light-functional film; the light-functional film is used for off-core packaging. The steps are as follows: first, SrAl2O4:Eu 2+ ,Dy 3+ Afterglow powder and SrS:Eu 2+ The afterglow powder is mixed evenly in a ratio of 1:0.01; then the A component and B component of Leining LN-103 A / B epoxy resin are weighed, and the A / B component ratio is 2:1; the mixed afterglow phosphor powder is added to the mixed LED packaging glue, and after being fully mixed again, it is allowed to stand and defoam; within a certain period of time, the mixed LED packaging glue containing the afterglow powder is applied on a flat substrate by scraping to make a layer of flexible optical functional film with added phosphor, and it is placed in an oven set at 60°C for curing for 3 hours to form, such as Figure 2 As shown, Figure 2 The figure is a photofunctional film of Example 1. Next, weigh the A component and B component of Leining LN-103 A / B epoxy resin LED encapsulation glue in a ratio of 2:1, mix them thoroughly and evenly, and then let them stand for a period of time to defoam. Pour the mixed epoxy LED encapsulation glue evenly into the mold to make a layer of transparent film without adding phosphor. The thickness of the transparent film is controlled to be 2 mm by the amount of mold and glue. Place it in an oven and set the temperature to 70°C for curing for 5 hours to form it. Figure 3 As shown, Figure 3 The transparent film without phosphor powder of Example 1 is shown in FIG. Finally, two layers of film are obtained, one layer of light functional film containing afterglow phosphor powder and the other layer of colorless transparent film without phosphor powder. The transparent film without afterglow powder is directly attached to the LED chip, and the light functional film containing afterglow powder is attached above the transparent film, so that an off-core packaged LED device can be formed, such as Figure 4 , Figure 4 This is a diagram of an off-core packaged LED device of Example 1, where the off-core distance a is 2 mm. The optical parameters thereof are shown in Table 1.

[0034] Example 2

[0035] Using SrAl2O4:Eu 2+ ,Dy 3+ Afterglow powder and SrS:Eu 2+Afterglow powder and commercial YAG yellow powder (Y3Al5O 12 :Ce) and LED packaging glue to prepare a light-functional film; use this light-functional film for off-core packaging. The steps are as follows: first, SrAl2O4:Eu 2+ ,Dy 3+ Afterglow powder, SrS:Eu 2+ The afterglow powder and commercial YAG yellow powder are mixed evenly in a ratio of 1:0.01:0.03; Dow Corning DC184 machine silicone A component and B component are weighed in a ratio of 10:1, and the mixed afterglow phosphor is added to the mixed LED packaging glue, and after being fully mixed again, it is allowed to stand for defoaming; within a certain period of time, the mixed LED packaging glue containing afterglow powder is applied on a flat substrate by spin coating to make a layer of optical functional film with added phosphor, which is placed in an oven set at 60°C for curing for 4 hours to form; then, Dow Corning DC184 machine silicone A component and B component are weighed in a ratio of 10:1, and after being fully mixed, it is allowed to stand for a period of time to defoam, and the mixed silicone LED packaging glue is evenly poured into the mold to make a layer of transparent film without phosphor, and the thickness of the transparent film is controlled to be 1 mm by the amount of mold and glue, and it is placed in an oven set at 70°C for curing for 5 hours to form. Finally, two layers of film are obtained, one layer of light functional film containing afterglow phosphor and the other layer of colorless transparent film without phosphor. The transparent film without afterglow powder is directly attached to the LED chip, and the light functional film containing afterglow powder is attached above the transparent film, so that an off-core packaged LED device can be formed, and its off-core distance a is 1 mm. Its optical parameters are shown in Table 1.

[0036] Example 3

[0037] Using SrAl2O4:Eu 2+ ,Dy 3+ Afterglow powder, SrS:Eu 2+ Afterglow powder and LED packaging glue are used to prepare a light-functional film; the light-functional film is used for off-core packaging. The steps are as follows: first, SrAl2O4:Eu 2+ ,Dy 3+ Afterglow powder and SrS:Eu 2+The afterglow powder is mixed evenly in a ratio of 1:0.01; Dow Corning DC184 machine silicone A component and B component are weighed in a ratio of 10:1, and the mixed afterglow phosphor is added to the mixed LED packaging glue, and after being fully mixed again, it is allowed to stand for defoaming; within a certain period of time, the mixed LED packaging glue containing afterglow powder is applied on a flat substrate by spin coating to make a layer of optical functional film with added phosphor, which is placed in an oven set at 60°C for curing for 4 hours to form; then, Dow Corning DC184 machine silicone A component and B component are weighed in a ratio of 10:1, and after being fully mixed, it is allowed to stand for a period of time to defoam, and the mixed silicone LED packaging glue is evenly poured into the mold to make a layer of transparent film without phosphor, and the thickness of the transparent film is controlled to be 3 mm by the amount of mold and glue, and it is placed in an oven set at 70°C for curing for 5 hours to form. Finally, two layers of film are obtained, one layer of light functional film containing afterglow phosphor and the other layer of colorless transparent film without phosphor. The transparent film without afterglow powder is directly attached to the LED chip, and the light functional film containing afterglow powder is attached above the transparent film, so that an off-core packaged LED device can be formed, and its off-core distance a is 1 mm. Its optical parameters are shown in Table 1.

[0038] Example 4

[0039] Using SrAl2O4:Eu 2+ ,Dy 3+ Afterglow powder and commercial YAG yellow powder (Y3Al5O 12 :Ce), 1113 nitride phosphor and LED packaging glue to prepare a light functional film; use this light functional film for off-core packaging. The steps are as follows: first, SrAl2O4:Eu 2+ ,Dy 3+ Afterglow powder, commercial YAG yellow powder and commercial 1113 nitride phosphor are mixed evenly in a ratio of 1:0.01:0.03; Dow Corning DC184 organic silica gel component A and component B are weighed in a ratio of 10:1, and the mixed afterglow phosphor is added to the mixed LED packaging glue, and after being fully mixed again, it is allowed to stand to defoam; a dam is made on a flat substrate, and the mixed LED packaging glue containing afterglow powder is poured into the dam within a certain period of time, and it is placed in an oven set at a temperature of 60°C for curing for 4 hours to form. The thickness of the optical functional film is controlled by the height of the dam, such as Figure 5 As shown, Figure 5This is a photofunctional film prepared in Example 4. Next, weigh Dow Corning DC184 organic silica gel component A and component B in a ratio of 10:1, mix them thoroughly and evenly, and then let them stand for a period of time to defoam. Pour the mixed organic silicone LED encapsulation glue evenly into the mold to make a layer of transparent film without phosphor. The thickness of the transparent film is controlled to be 1 mm by the amount of mold and glue. Place it in an oven and set the temperature to 70°C for 3 hours to cure. Finally, two layers of film are obtained, one layer of photofunctional film containing afterglow phosphor and the other layer of colorless transparent film without phosphor. The transparent film without afterglow powder is directly attached to the LED chip, and the photofunctional film containing afterglow powder is attached above the transparent film. A LED device with off-core packaging can be formed, and its distance a from the core is 1 mm. Its optical parameters are shown in Table 1.

[0040] Example 5

[0041] Using SrAl2O4:Eu 2+ ,Dy 3+ Afterglow powder and LED packaging glue are used to prepare a light-functional film; the light-functional film is used for off-core packaging. The steps are as follows: first, weigh Dow Corning DC184 organic silica gel component A and component B in a ratio of 10:1, and mix SrAl2O4:Eu 2+ ,Dy 3+ Afterglow powder and LED encapsulation glue are added to the mixed LED encapsulation glue in a ratio of 6:1, and after being fully mixed, the mixture is allowed to stand for defoaming; within a certain period of time, the mixed LED encapsulation glue containing afterglow powder is applied to a flat substrate by spin coating to make a layer of optical functional film with added fluorescent powder, which is placed in an oven and set to 70°C for curing for 4 hours to form; then, Dow Corning DC184 organic silicone component A and component B are weighed in a ratio of 10:1, and after being fully mixed, the mixture is allowed to stand for a period of time for defoaming, and the mixed silicone LED encapsulation glue is evenly poured into the mold to make a layer of transparent film without fluorescent powder. The thickness of the transparent film is controlled to be 1 mm by the amount of mold and glue, and the film is placed in an oven and set to 70°C for curing for 3 hours to form. Finally, two layers of film are obtained, one layer of light functional film containing afterglow phosphor and the other layer of colorless transparent film without phosphor. The transparent film without afterglow powder is directly attached to the LED chip, and the light functional film containing afterglow powder is attached above the transparent film, so that an off-core packaged LED device can be formed, such as Figure 6 As shown, Figure 6 This is a diagram of an off-core packaged LED device of Example 5, where the off-core distance a is 1 mm. The optical parameters thereof are shown in Table 1.

[0042] Example 6

[0043] Using SrAl2O4:Eu 2+ ,Dy 3+Afterglow powder, 1113 nitride phosphor and commercial YAG yellow powder (Y3Al5O 12 :Ce) and LED packaging glue to prepare a light-functional film; use this light-functional film for off-core packaging. The steps are as follows: first, SrAl2O4:Eu 2+ ,Dy 3+ The afterglow powder, 1113 nitride phosphor and commercial powder YAG are mixed evenly in a ratio of 1:0.03:0.01; the Dow Corning DC184 organic silica gel component A and component B are weighed in a ratio of 10:1, and the mixed afterglow phosphor is added to the mixed LED packaging glue, and after being fully mixed again, it is allowed to stand for defoaming; within a certain period of time, the mixed LED packaging glue containing the afterglow powder is applied on a flat substrate by spin coating to make a layer of light functional film with added phosphor, and the film is placed in an oven at a temperature of 70°C and cured for 4 hours to form; a bracket for placing the light functional film containing the afterglow powder is designed, and the light functional film containing the afterglow powder is placed on the bracket to form an off-core packaged LED device, such as Figure 7 As shown, Figure 7 This is a schematic diagram of an LED device using a bracket to package an afterglow light functional film off-core in Example 6, wherein the distance a from the core is 3 cm, and the optical parameters thereof are shown in Table 1.

[0044] Table 1

[0045]

[0046] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for packaging afterglow powder of an LED device, characterized in that: The following steps are involved: The rare earth doped afterglow powder, LED phosphor and LED packaging adhesive are made into a film, and the obtained film is fixed on the LED chip at a distance of 100 μm to 5 cm; The rare earth doped afterglow powder is selected from one or more of rare earth doped sulfide long afterglow luminescent materials, rare earth doped aluminate long afterglow luminescent materials, rare earth doped silicate long afterglow luminescent materials, rare earth doped titanate long afterglow luminescent materials or rare earth doped nitride long afterglow luminescent materials; The LED phosphor is selected from one or more of rare earth doped YAG, rare earth doped LuAG, rare earth doped CaAlSiN3 or rare earth doped Sr2Si5N8.

2. The afterglow powder packaging method of LED device according to claim 1, characterized in that: The rare earth doped afterglow powder is one or more of SrAl2O4:Eu,Dy, (Sr,Ca)S:Eu or Sr2MgSi2O7:Eu; The LED phosphor is selected from Y3Al5O 12 :Ce, 1113 nitride phosphor or 258 nitride red fluorescent phosphor.

3. The afterglow powder packaging method of LED device according to claim 1, characterized in that: The membrane is fixed above the LED chip at a distance of 500 μm to 5 mm.

4. The afterglow powder packaging method of LED device according to claim 1, characterized in that: The rare earth doped afterglow powder, LED fluorescent powder and LED packaging adhesive are coated on the substrate or injection molded, and cured to obtain a membrane.

5. The afterglow powder packaging method of LED device according to claim 4, characterized in that: The curing temperature is 50° C. to 80° C., and the curing time is 1 h to 5 h.

6. The afterglow powder packaging method of an LED device according to any one of claims 1 to 5, characterized in that: Fixing the membrane above the LED chip by a bracket; Alternatively, a transparent film is arranged between the film and the LED chip, and the film is fixed above the LED chip through the transparent film.

7. The afterglow powder packaging method of LED device according to claim 6, characterized in that: The LED packaging adhesive is selected from one or more of epoxy resin, organic silicone, polyurethane adhesive or organic adhesive.

8. The afterglow powder packaging method of LED device according to claim 6, characterized in that: The LED chip is selected from a gallium nitride LED chip, an aluminum phosphide LED chip or a silicon carbide LED chip.

9. The afterglow powder packaging method of LED device according to claim 6, characterized in that: The emission wavelength of the LED chip is 420 nm to 470 nm.

10. An afterglow powder encapsulated LED device obtained by using the afterglow powder encapsulation method described in any one of claims 1 to 9.

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