Multilayer fluorescent film and LED lamp bead
By using a multi-layer fluorescent film structure, combining a flexible transparent adhesive layer with an encapsulating adhesive layer, the problem of bonding the fluorescent film to the LED chip is solved, improving luminous efficiency and heat resistance, and reducing the risk of cracking.
Patent Information
- Application Number
- CN202423157248.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-19
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2034-12-19
AI Technical Summary
In existing technologies, the high hardness of the fluorescent film prevents it from bonding tightly with the LED chip, resulting in air bubbles that affect luminous efficiency. Furthermore, the phosphor excitation efficiency is low at high temperatures, and the fluorescent film has a high probability of cracking.
The LED chip is made of a multi-layer fluorescent film structure, including a flexible transparent adhesive layer and an encapsulating adhesive layer. The flexible transparent adhesive layer is bonded to the LED chip, and fluorescent particles are placed in the encapsulating adhesive layer. The LED chip is isolated from the encapsulating adhesive layer by the flexible transparent adhesive layer. The Shore hardness of the flexible transparent adhesive layer is D20-D40, and the Shore hardness of the encapsulating adhesive layer is D40-D60, so as to achieve tight bonding and heat isolation.
This method achieves tight bonding between the fluorescent film and the LED chip, improves the excitation efficiency of the phosphor, reduces the probability of the fluorescent film cracking, and expands the applicable temperature range.
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Figure CN223613768U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to LED chip packaging technical field especially, and relates to a multilayer fluorescent film and LED lamp pearl. BACKGROUND
[0002] In the production of LED (Light Emitting Diode, emitting diode) lamp pearl, the fluorescent film is formed by mixing silica gel and fluorescent powder and hot scraping, and then the fluorescent film is cut into square film pieces according to the size of LED chip and covered on the light emitting surface of LED chip.
[0003] In order to ensure the hardness of the fluorescent film, the silica gel with slightly higher hardness is usually used, because there is height difference on the surface of LED chip, when the fluorescent film is covered on the LED chip, the LED chip and the fluorescent film cannot be closely combined due to the high hardness of the fluorescent film, there is air bubble between the LED chip and the fluorescent film, which affects the light emitting efficiency, in addition, the surface temperature of the LED chip is high during use, which makes the excitation efficiency of the fluorescent powder low, and the high temperature makes the high-hardness fluorescent film crack.
[0004] Therefore, the prior art still needs to be improved and developed. INVENTION CONTENTS
[0005] In view of the above problems of the prior art, the utility model aims at providing a multilayer fluorescent film and LED lamp pearl to solve the problems that the hardness of the fluorescent film is high in the prior art, the LED chip and the fluorescent film cannot be closely combined when the fluorescent film is directly covered on the LED chip, there is air bubble between the LED chip and the fluorescent film, which affects the light emitting efficiency, the surface temperature of the LED chip is high during use, which makes the excitation efficiency of the fluorescent powder low, and the high temperature makes the high-hardness fluorescent film crack.
[0006] The utility model provides a multilayer fluorescent film for packaging LED chip, the multilayer fluorescent film includes: flexible transparent adhesive layer and encapsulation adhesive layer, the encapsulation adhesive layer is provided with fluorescent particle, the upper surface of flexible transparent adhesive layer is pasted with the lower surface of encapsulation adhesive layer, and the lower surface of flexible transparent adhesive layer is pasted on the light emitting surface of LED chip.
[0007] The utility model further provides that the flexible transparent adhesive layer is a transparent soft silica gel layer.
[0008] The utility model further provides that the Shore hardness range of the transparent soft silica gel layer is D20-D40.
[0009] The utility model further provides that the encapsulation adhesive layer is a silica gel layer, and the silica gel layer is provided with fluorescent particles.
[0010] The further setting of the utility model discloses, the encapsulation adhesive layer at least includes the first sub-silica gel layer and the second sub-silica gel layer that set from bottom to top, the first sub-silica gel layer is provided with the fluorescent particle of the first color, the second sub-silica gel layer is provided with the fluorescent particle of the second color, wherein, the lower surface of the first sub-silica gel layer is attached with the upper surface of the flexible transparent adhesive layer.
[0011] The further setting of the utility model discloses, the hardness range of silica gel in the encapsulation adhesive layer is D40-D60.
[0012] The further setting of the utility model discloses, the encapsulation adhesive layer at least includes the third sub-silica gel layer, the fourth sub-silica gel layer and the fifth sub-silica gel layer that set from bottom to top;
[0013] The fourth sub-silica gel layer is provided with the fluorescent particle of the fourth color;
[0014] The fifth sub-silica gel layer is provided with the fluorescent particle of the fifth color;
[0015] The third sub-silica gel layer is divided into at least the first area and the second area, the first area is transparent layer, and the third color fluorescent particle is arranged in the second area;
[0016] The lower surface of the third sub-silica gel layer is attached with the upper surface of the flexible transparent adhesive layer.
[0017] The further setting of the utility model discloses, the hardness range of silica gel in the encapsulation adhesive layer is D40-D60.
[0018] The utility model discloses still provide a kind of LED lamp pearl, it include: support, the LED chip of being set on the support and the multilayer fluorescent film as described above that is attached on the light-emitting surface of the LED chip.
[0019] The utility model discloses has the beneficial effect that:
[0020] The utility model provides a kind of multilayer fluorescent film and LED lamp pearl, multilayer fluorescent film is used to package LED chip, the multilayer fluorescent film includes flexible transparent adhesive layer and encapsulation adhesive layer, the encapsulation adhesive layer is provided with fluorescent particle, the upper surface of the flexible transparent adhesive layer is attached with the lower surface of the encapsulation adhesive layer, and the lower surface of the flexible transparent adhesive layer is attached on the light-emitting surface of the LED chip.In the utility model technical scheme, because the flexible transparent adhesive layer is attached in multilayer fluorescent film and LED chip, therefore, the multilayer fluorescent film and LED chip can be closely attached between, and the encapsulation adhesive layer mixed with fluorescent powder is separated from LED chip by flexible transparent adhesive layer, and the excitation efficiency of fluorescent powder is higher, simultaneously, the probability of multilayer fluorescent film cracking is lower. BRIEF DESCRIPTION OF DRAWINGS
[0021] In order to more clearly illustrate the technical features, objectives and effects of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings described below are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained according to the structures shown in these drawings without creative labor.
[0022] Figure 1 is the structure diagram of the multi-layer fluorescent film in the present application.
[0023] Figure 2 is the structure diagram of the multi-layer fluorescent film in an embodiment of the present application.
[0024] Figure 3 is the structure diagram of the multi-layer fluorescent film in another embodiment of the present application.
[0025] Figure 4 is the cross-sectional structure diagram of the fluorescent film in the prior art in the present application.
[0026] Figure 5 is the installation structure diagram of the fluorescent film in the prior art in the present application on the LED chip.
[0027] The marks in the drawings are as follows: 11, LED chip; 10, multi-layer fluorescent film; 101, flexible transparent adhesive layer; 102, encapsulating adhesive layer; 1021, first sub-silicone layer; 1022, second sub-silicone layer; 1023, third sub-silicone layer; 1024, fourth sub-silicone layer; 1025, fifth sub-silicone layer; 12, fluorescent film. DETAILED DESCRIPTION
[0028] In order to have a clearer understanding of the technical features, objectives and effects of the present application, the specific embodiments of the present application will be described in detail with reference to the drawings. In the following description, it should be understood that the directions or position relationships indicated by "front", "back", "up", "down", "left", "right", "vertical", "horizontal", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", "tail" and the like are based on the directions or position relationships shown in the drawings, constructed and operated in a particular direction, and are only for the convenience of describing the technical scheme, and cannot be understood as indicating that the devices or elements indicated must have a particular direction, therefore, it cannot be understood as a limitation of the present application.
[0029] In the prior art, silicone and fluorescent powder are mixed and then hot scraped to form a fluorescent film 12, and then the fluorescent film 12 is cut into a square film piece according to the size of the LED chip 11 to cover the light emitting surface of the LED chip 11.
[0030] For example, the fluorescent film 12 is cut into a square film piece according to the size of the LED chip 11 to cover the light emitting surface of the LED chip 11. Figure 4As shown in the figure, it is a cross-sectional structure diagram of the fluorescent film 12 formed in the prior art. Figure 5 As shown in the figure, it is the application of the fluorescent film formed in the prior art on the LED chip 11. In the fluorescent film 12 formed in the prior art, in order to ensure the hardness of the fluorescent film 12, a slightly higher hardness silica gel is usually used. When the fluorescent film formed by the slightly higher hardness silica gel is applied, because there is a height difference on the surface of the LED chip 11, when the fluorescent film 12 is covered on the LED chip 11, the LED chip 11 and the fluorescent film cannot be closely attached, there is air bubble between the LED chip 11 and the fluorescent film 12, which affects the light emitting efficiency. In addition, the surface temperature of the LED chip 11 is high when it is used, which makes the excitation efficiency of the fluorescent powder low, and the high temperature makes the probability of cracking of the fluorescent film 12 with high hardness high.
[0031] Based on the above technical problems, the utility model provides a multilayer fluorescent film 10. As shown in the figure, Figure 1 , Figure 2 As shown in the figure, the multilayer fluorescent film 10 can include a flexible transparent adhesive layer 101 and an encapsulation adhesive layer 102, the encapsulation adhesive layer 102 is provided with fluorescent particles, the upper surface of the flexible transparent adhesive layer 101 is attached to the lower surface of the encapsulation adhesive layer 102, and the lower surface of the flexible transparent adhesive layer 101 is attached to the light emitting surface of the LED chip 11.
[0032] Specifically, the flexible transparent adhesive layer 101 in the multilayer fluorescent film 10 is attached to the light emitting surface of the LED chip 11, the encapsulation adhesive layer 102 provided with fluorescent particles is isolated from the LED chip 11 through the flexible transparent adhesive layer 101, so that the heat of the LED chip 11 is first transmitted to the flexible transparent adhesive layer 101 and then transmitted from the flexible transparent adhesive layer 101 to the encapsulation adhesive layer 102 provided with fluorescent particles. Compared with the one layer provided with fluorescent particles directly attached to the LED chip 11 in the prior art, the temperature of the encapsulation adhesive layer 102 is reduced. When the fluorescent particles are excited in particular, the light emitted after the LED chip 11 is lit excites the fluorescent particles in the encapsulation adhesive layer 102 after the flexible transparent adhesive layer 101, so that the LED lamp bead emits light normally. Therefore, the flexible transparent adhesive layer 101 does not affect the normal light emission of the LED lamp bead when isolating the LED chip 11 and the encapsulation adhesive layer 102 provided with fluorescent particles.
[0033] In the embodiment, because the flexible transparent adhesive layer 101 is attached to the LED chip 11 in the multilayer fluorescent film 10, the multilayer fluorescent film 10 and the LED chip 11 can be closely attached, and the encapsulation adhesive layer 102 provided with fluorescent particles is isolated from the LED chip 11 through the flexible transparent adhesive layer 101, so that the excitation efficiency of the fluorescent particles is high, and the probability of cracking of the multilayer fluorescent film is low.
[0034] In some embodiments, the flexible transparent adhesive layer 101 is a transparent soft silica gel layer.
[0035] In the embodiment, since the transparent soft silicone layer 101 is adopted, the heat resistance of the multi-layer fluorescent film 10 is improved, and the temperature range of the multi-layer fluorescent film 10 is wider than that of the fluorescent film in the prior art.
[0036] In some embodiments, the shore hardness of the transparent soft silicone layer is controlled to be between D20 and D40 when the transparent soft silicone layer is prepared.
[0037] Specifically, the shore hardness of the transparent soft silicone layer can be D20 when the transparent soft silicone layer is prepared. Of course, it can also be D25, D28, D30, D34, D36, D40, etc. The shore hardness of the transparent soft silicone layer can be determined by the person skilled in the art according to the actual situation.
[0038] In the embodiment, the shore hardness of the transparent soft silicone layer is controlled to be between D20 and D40, so that the transparent soft silicone layer not only can be attached to the light-emitting surface of the LED chip 11, but also can support the encapsulation glue layer 102 provided with fluorescent particles.
[0039] In some embodiments, the encapsulation glue layer is a silicone layer, and the silicone layer is provided with fluorescent particles.
[0040] In some embodiments, as shown in FIGS. 1, 2 and 3, the encapsulation glue layer 102 includes at least a first sub-silicone layer 1021 and a second sub-silicone layer 1022 stacked from bottom to top, the first sub-silicone layer 1021 is provided with fluorescent particles of a first color, and the second sub-silicone layer 1022 is provided with fluorescent particles of a second color, wherein the lower surface of the first sub-silicone layer 1021 is attached to the upper surface of the flexible transparent glue layer 101. Figure 1 、 Figure 2 Specifically, when the encapsulation glue layer 102 is prepared, the first sub-silicone layer 1021 is prepared by mixing fluorescent particles of a single color (fluorescent particles of the first color) with silicone and stacked on the flexible transparent glue layer 101; then the second sub-silicone layer 1022 is prepared by mixing fluorescent particles of a single color (fluorescent particles of the second color) with silicone and stacked on the first sub-silicone layer 1021, and the lower surface of the second sub-silicone layer 1022 is attached to the upper surface of the first sub-silicone layer 1021.
[0041] Specifically, when the encapsulation glue layer 102 is prepared, the first sub-silicone layer 1021 is prepared by mixing fluorescent particles of a single color (fluorescent particles of the first color) with silicone and stacked on the flexible transparent glue layer 101; then the second sub-silicone layer 1022 is prepared by mixing fluorescent particles of a single color (fluorescent particles of the second color) with silicone and stacked on the first sub-silicone layer 1021, and the lower surface of the second sub-silicone layer 1022 is attached to the upper surface of the first sub-silicone layer 1021.
[0042] The color of the fluorescent particles in the first sub-silicone layer 1021 and the color of the fluorescent particles in the second sub-silicone layer 1022 can be determined as needed, and will not be limited herein. Of course, a sub-silicone layer mixed with other fluorescent particles can also be stacked on the second sub-silicone layer 1022 according to actual needs, which will not be described in detail herein.
[0043] In the embodiment, the fluorescent particles of each color are separately made into a sub-silica gel layer, so that when the light emitted by the LED chip 11 is used to excite the fluorescent particles in each sub-silica gel layer, the excitation efficiency is high.
[0044] In a specific embodiment, the first sub-silica gel layer 1021 is provided with red fluorescent particles, the second sub-silica gel layer 1022 is provided with yellow-green fluorescent particles, and the LED chip 11 is a blue LED chip 11, and the flexible transparent adhesive layer 101 is a transparent soft silica gel layer.
[0045] In a specific application, when the blue LED chip 11 is turned on, the blue light reaches the first sub-silica gel layer 1021 through the flexible transparent adhesive layer 101, part of the blue light excites the red fluorescent particles to emit red light, and the excited red light and the other blue light reach the second sub-silica gel layer 1022, part of the other blue light excites the yellow-green fluorescent particles to emit yellow-green light, and the excited yellow-green light, red light and the last remaining blue light mix to emit the required white light.
[0046] In the embodiment, the first sub-silica gel layer 1021 absorbs yellow-green light to excite red light, but the conversion efficiency of absorbing yellow-green light to excite red light is poor, and the above layered mode improves the excitation efficiency of the fluorescent particles in each layer.
[0047] In some embodiments, the Shore hardness of the silica gel in the packaging adhesive layer 102 ranges from D40 to D60.
[0048] Specifically, when the packaging adhesive layer 102 is prepared, the Shore hardness of the silica gel can be D40, of course, it can also be D45, D48, D50, D55, D57, D60, etc., and the Shore hardness of the silica gel in the packaging adhesive layer 102 can be determined by the person skilled in the art according to the actual situation.
[0049] It should be noted that when the packaging adhesive layer 102 is layered, the Shore hardness of the silica gel used in each layer can be the same, or the Shore hardness of the silica gel used in each layer can be different, or when the packaging adhesive layer 102 is more than two layers, the Shore hardness of the silica gel used in part of the layers can be the same, and the Shore hardness of the silica gel in the packaging adhesive layer 102 can be determined by the person skilled in the art according to the actual situation.
[0050] In the embodiment, the hardness of the silica gel in the packaging adhesive layer 102 is high, so that the multi-layer fluorescent film 10 formed is not easy to deform.
[0051] In some embodiments, as Figure 3As shown, the encapsulation adhesive layer 102 at least includes a third sub-silicone adhesive layer 1023, a fourth sub-silicone adhesive layer 1024 and a fifth sub-silicone adhesive layer 1025 stacked from bottom to top; the fourth sub-silicone adhesive layer 1024 is provided with fluorescent particles of a fourth color; the fifth sub-silicone adhesive layer 1025 is provided with fluorescent particles of a fifth color; the third sub-silicone adhesive layer 1023 is at least divided into a first region and a second region, the first region is a transparent layer, and the second region is provided with fluorescent particles of a third color; and the lower surface of the third sub-silicone adhesive layer 1023 is attached to the upper surface of the flexible transparent adhesive layer 101.
[0052] Specifically, when the third sub-silicone adhesive layer 1023 is divided, it is divided into two regions (the first region and the second region), and the fourth sub-silicone adhesive layer 1024 and the fifth sub-silicone adhesive layer 1025 are sequentially stacked on the third sub-silicone adhesive layer 1023.
[0053] After the LED chip 11 applied with the multi-layer fluorescent film 10 is lighted, the LED chip 11 emits first light, part of which reaches the first region and part of which reaches the second region, and the light reaching the first region is mixed by the fourth sub-silicone adhesive layer 1024 and the fifth sub-silicone adhesive layer 1025 to form a bundle of outgoing light; and the light reaching the second region is mixed by the fourth sub-silicone adhesive layer 1024 and the fifth sub-silicone adhesive layer 1025 to form a bundle of outgoing light.
[0054] In this embodiment, since the first region is a transparent layer and the second region is provided with the third particles, the color temperature of the outgoing light mixed by the first region, the fourth sub-silicone adhesive layer 1024 and the fifth sub-silicone adhesive layer 1025 is different from the color temperature of the outgoing light mixed by the second region, the fourth sub-silicone adhesive layer 1024 and the fifth sub-silicone adhesive layer 1025, and multiple color temperatures of light can be formed, i.e., the multi-layer fluorescent film 10 is a multi-color fluorescent film.
[0055] In a specific embodiment, the LED chip 11 is a blue light LED chip 11, the fluorescent particles in the second region are deep red fluorescent particles, the fourth sub-silicone adhesive layer 1024 is provided with red fluorescent particles, and the fifth sub-silicone adhesive layer 1025 is provided with yellow-green fluorescent particles, wherein, after the LED chip 11 is lighted, the deep red fluorescent particles, the red fluorescent particles and the yellow-green fluorescent particles mix to emit low-color-temperature white light, and the red fluorescent particles and the yellow-green fluorescent particles mix to emit high-color-temperature white light, forming a dual-color-temperature fluorescent film.
[0056] In some embodiments, the Shore hardness of the silicone adhesive in the encapsulation adhesive layer 102 ranges from D40 to D60.
[0057] Specifically, in preparation of the encapsulation adhesive layer 102, the Shore hardness of the silica gel can be D40, of course, can also be D45, D48, D50, D55, D57, D60, etc., and the person skilled in the art can determine the Shore hardness of the silica gel in the preparation of the encapsulation adhesive layer 102 according to the actual situation.
[0058] It should be noted that when the encapsulation adhesive layer 102 is arranged in a layered manner, the Shore hardness of the silica gel used in each layer can be the same, or the Shore hardness of the silica gel used in each layer can be different, or when the encapsulation adhesive layer 102 is three or more layers, the Shore hardness of the silica gel used in part of the layers can be the same, and the person skilled in the art can determine the Shore hardness of the silica gel in the encapsulation adhesive layer 102 according to the actual situation.
[0059] In this embodiment, the hardness of the silica gel in the encapsulation adhesive layer 102 is high, so that the multi-layer fluorescent film 10 formed is not easy to deform.
[0060] In some embodiments, the utility model also provides a LED lamp bead, which can include a support, an LED chip 11 arranged on the support, and a multi-layer fluorescent film 10 as described above attached to the light-emitting surface of the LED chip 11.
[0061] As shown in Figure 1 , Figure 2 , the multi-layer fluorescent film 10 can include a flexible transparent adhesive layer 101 and an encapsulation adhesive layer 102, the encapsulation adhesive layer 102 is provided with fluorescent particles, the upper surface of the flexible transparent adhesive layer 101 is attached to the lower surface of the encapsulation adhesive layer 102, and the lower surface of the flexible transparent adhesive layer 101 is attached to the light-emitting surface of the LED chip 11.
[0062] Specifically, the flexible transparent adhesive layer 101 in the multi-layer fluorescent film 10 is attached to the light-emitting surface of the LED chip 11, and the encapsulation adhesive layer 102 provided with fluorescent particles is isolated from the LED chip 11 by the flexible transparent adhesive layer 101, so that the heat of the LED chip 11 in use is first transmitted to the flexible transparent adhesive layer 101 and then transmitted from the flexible transparent adhesive layer 101 to the encapsulation adhesive layer 102 provided with fluorescent particles, and compared with the prior art in which a layer provided with fluorescent particles is directly attached to the LED chip 11, the temperature of the encapsulation adhesive layer 102 is reduced. In the process of exciting the fluorescent particles, the light emitted by the LED chip 11 after being lit excites the fluorescent particles in the encapsulation adhesive layer 102 after passing through the flexible transparent adhesive layer 101, so that the LED lamp bead emits light normally, and therefore, the flexible transparent adhesive layer 101 does not affect the normal light emission of the LED lamp bead when isolating the LED chip 11 from the encapsulation adhesive layer 102 provided with fluorescent particles.
[0063] In the embodiment, the flexible transparent adhesive layer 101 is arranged between the multi-layer fluorescent film 10 and the LED chip 11, so that the multi-layer fluorescent film 10 and the LED chip 11 can be closely attached, and the encapsulation adhesive layer 102 containing the fluorescent particles is separated from the LED chip 11 by the flexible transparent adhesive layer 101, the excitation efficiency of the fluorescent particles is high, and the cracking probability of the multi-layer fluorescent film 10 is low.
[0064] Here, it should be pointed out that the above LED lamp bead embodiment is similar to the above multi-layer fluorescent film 10 embodiment, and has the similar beneficial effects of the above multi-layer fluorescent film 10. For technical details not disclosed in the LED lamp bead embodiment, please refer to the description of the multi-layer fluorescent film 10 embodiment of the utility model for understanding.
[0065] In summary, the multi-layer fluorescent film and the LED lamp bead have the following effects:
[0066] In the embodiment, the flexible transparent adhesive layer 101 is arranged between the multi-layer fluorescent film 10 and the LED chip 11, so that the multi-layer fluorescent film 10 and the LED chip 11 can be closely attached, and the encapsulation adhesive layer 102 containing the fluorescent particles is separated from the LED chip 11 by the flexible transparent adhesive layer 101, the excitation efficiency of the fluorescent particles is high, and the cracking probability of the multi-layer fluorescent film 10 is low.
[0067] It can be understood that the above embodiment only expresses the preferred embodiment of the utility model, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the utility model patent; it should be pointed out that for ordinary skilled persons in the art, the above technical features can be freely combined without departing from the concept of the utility model, and some deformations and improvements can be made, which belong to the protection scope of the utility model; therefore, any equivalent transformation and modification within the scope of the utility model claim should belong to the scope of the utility model claim.
Claims
1. A multi-layer phosphor film for encapsulating an LED chip, characterized by, The multilayer fluorescent film comprises a flexible transparent adhesive layer and an encapsulating adhesive layer provided with fluorescent particles, the upper surface of the flexible transparent adhesive layer is attached to the lower surface of the encapsulating adhesive layer, and the lower surface of the flexible transparent adhesive layer is attached to the light emitting surface of the LED chip.
2. The multi-layer fluorescent film of claim 1, wherein, The flexible transparent adhesive layer is a transparent soft silicone adhesive layer.
3. The multi-layer fluorescent film of claim 2, wherein, The Shore hardness of the transparent soft silicone adhesive layer ranges from D20 to D40.
4. The multi-layer fluorescent film according to any one of claims 1 to 3, wherein, The encapsulating adhesive layer is a silicone adhesive layer provided with fluorescent particles.
5. The multi-layer fluorescent film of claim 4, wherein, The encapsulating adhesive layer comprises at least a first sub-silicone adhesive layer and a second sub-silicone adhesive layer stacked from bottom to top, the first sub-silicone adhesive layer is provided with fluorescent particles of a first color, and the second sub-silicone adhesive layer is provided with fluorescent particles of a second color, wherein the lower surface of the first sub-silicone adhesive layer is attached to the upper surface of the flexible transparent adhesive layer.
6. The multi-layer fluorescent film of claim 5, wherein, The Shore hardness of the silicone adhesive in the encapsulating adhesive layer ranges from D40 to D60.
7. The multi-layer fluorescent film of claim 4, wherein, The encapsulating adhesive layer comprises at least a third sub-silicone adhesive layer, a fourth sub-silicone adhesive layer and a fifth sub-silicone adhesive layer stacked from bottom to top. The fourth sub-silicone adhesive layer is provided with fluorescent particles of a fourth color. The fifth sub-silicone adhesive layer is provided with fluorescent particles of a fifth color. The third sub-silicone adhesive layer is divided into at least a first region and a second region, the first region is a transparent layer, and the second region is provided with fluorescent particles of a third color. The lower surface of the third sub-silicone adhesive layer is attached to the upper surface of the flexible transparent adhesive layer.
8. The multi-layer fluorescent film of claim 7, wherein, The Shore hardness of the silicone adhesive in the encapsulating adhesive layer ranges from D40 to D60.
9. An LED lamp bead, characterized in that, It comprises: a support, an LED chip arranged on the support, and the multilayer fluorescent film as claimed in any one of claims 1 to 8 attached to the light emitting surface of the LED chip.