Sandwich fluorescent structure and white light LED lighting assembly

Abstract

The utility model discloses a sandwich fluorescent structure and white light LED lighting assembly, including main body structure layer and excitation source, the excitation source is blue light LED chip, the upper end of main body structure layer is equipped with green light emitting layer, the lower end is equipped with red light emitting layer, the upper end is equipped with red light emitting layer, and the red light emitting layer is equipped with red light emitting layer. A light source of the excitation source passes through the red light emission layer, the main body structure layer and the green light emission layer in sequence after being excited, and the main body structure layer is a YAG (yttrium aluminum garnet) sheet-shaped ceramic layer. The green light emitting layer, the YAG sheet-shaped ceramic layer and the red light emitting layer are sequentially arranged from top to bottom, the YAG sheet-shaped ceramic layer is arranged between the green light emitting layer and the red light emitting layer, and the green light emitting layer and the red light emitting layer are separated by the YAG sheet-shaped ceramic layer, so that reabsorption of multi-color light when the green light emitting layer and the red light emitting layer are tightly arranged is avoided, and the light emitting efficiency is improved. The technical problems that according to an illumination structure in the prior art, a red fluorescent film and green fluorescent ceramic are tightly attached, so that light of various colors is re-absorbed, and the luminous intensity is attenuated are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of white LED lighting, in particular to a sandwich fluorescent structure and a white LED lighting component. Background Art

[0002] The fluorescence conversion type solid-state lighting technology has become a current research hotspot, which has the advantages of high luminous efficiency, energy conservation and environmental protection, and long service life. At present, the mainstream packaging scheme of white LEDs is white LED + silicone grease and yellow fluorescent powder. The thermal conductivity of this type of fluorescent material is usually less than 1 Wm-1K-1, and it is difficult to withstand waste heat shock. Therefore, fluorescent materials with high thermal conductivity have become the research focus.

[0003] For example, the patent with publication number CN117781248A proposes a composite fluorescent ceramic for high-power LD lighting and its preparation method. The composite fluorescent ceramic is composed of a red fluorescent thin film, a green fluorescent ceramic, a transparent oxide ceramic, and a concave heat-conducting structure layer from top to bottom; Preparation method: Prepare the mixed raw material powders corresponding to the red fluorescent thin film, the green fluorescent ceramic, and the transparent oxide ceramic. The mixed raw material powder of the red fluorescent thin film is obtained by glass melting, quenching, and grinding to obtain a precursor fluorescent glass powder, and further obtain a fluorescent glass colloid; Prepare the heat-conducting layer composite ceramic from the mixed raw material powders corresponding to the green fluorescent ceramic and the transparent oxide ceramic; Coat the fluorescent glass colloid on the surface of the heat-conducting layer composite ceramic, and after crystallization, embed it into the concave heat-conducting structure layer to obtain the composite fluorescent ceramic.

[0004] The above-mentioned disclosed composite fluorescent ceramic is a fluorescent material with high thermal conductivity. However, the above-mentioned composite fluorescent ceramic is composed of a red fluorescent thin film, a green fluorescent ceramic, a transparent oxide ceramic, and a concave heat-conducting structure layer from top to bottom. Setting the red fluorescent thin film and the green fluorescent ceramic closely will cause multi-color light reabsorption, which will in turn cause problems such as attenuation of luminous intensity and influence on the light propagation distance. Summary of the Utility Model

[0005] Aiming at the deficiencies in the above background art, the utility model proposes a sandwich fluorescent structure and a white LED lighting component, which solve the technical problem that the existing lighting structure sets the red fluorescent thin film and the green fluorescent ceramic closely, resulting in multi-color light reabsorption and attenuation of luminous intensity.

[0006] The technical solution of the utility model is realized as follows: A sandwich fluorescent structure includes a main structure layer. A green light emitting layer is provided at the upper end of the main structure layer, and a red light emitting layer is provided at the lower end. After being excited by the light source of the excitation source, it sequentially passes through the red light emitting layer, the main structure layer, and the green light emitting layer. The main structure layer is a YAG sheet ceramic layer.

[0007] Preferably, the cross-section of the sandwich fluorescent structure is circular with a diameter of W, and the diameter of the light-emitting surface of the blue LED chip is Z, where Z:W = 1.1 mm to 1.2 mm.

[0008] Preferably, the height of the YAG sheet ceramic layer is H, where 0.8 mm ≤ H ≤ 1.2 mm.

[0009] Preferably, the green light-emitting layer is LuAG:Ce 3+ fluorescent glass thin film layer.

[0010] Preferably, the red light-emitting layer is (Sr,Ca)AlSiN3:Eu 2+ fluorescent glass thin film layer.

[0011] Preferably, the (Sr,Ca)AlSiN3:Eu 2+ and LuAG:Ce 3+ both have particle sizes between 200 nm and 250 nm.

[0012] Preferably, the concentration ratio of the green light-emitting layer to the red light-emitting layer is Y, where 1.05 mm ≤ Y ≤ 1.2 mm.

[0013] Preferably, the area ratio of the green light-emitting layer to the red light-emitting layer is X, where 1 mm ≤ X ≤ 1.05 mm.

[0014] A white LED lighting component includes an excitation source, a first heat sink, a second heat sink, and the above-mentioned sandwich fluorescent structure. The excitation source is a blue LED chip. The excitation source is located between the first heat sink and the second heat sink. A cover plate is provided on the top of the first heat sink. The sandwich fluorescent structure is located between the first heat sink and the cover plate, and the sandwich fluorescent structure is directly above the excitation source.

[0015] Preferably, the emission wavelength of the excitation source is 455 nm - 465 nm.

[0016] Advantages of the present utility model:

[0017] 1. In the sandwich fluorescent structure of the present application, the green light-emitting layer, the YAG sheet ceramic layer, and the red light-emitting layer are arranged in sequence from top to bottom. The YAG sheet ceramic layer is provided between the green light-emitting layer and the red light-emitting layer, separating the green light-emitting layer and the red light-emitting layer, avoiding the problem of multi-color light reabsorption and resulting in attenuation of the light-emitting intensity when the green light-emitting layer and the red light-emitting layer are closely arranged.

[0018] 2. The green light-emitting layer of the present application is a LuAG:Ce 3+ fluorescent glass thin film layer, and the red light-emitting layer is (Sr,Ca)AlSiN3:Eu 2+The fluorescent glass thin film layer, and thin film layers are provided on both the top and bottom surfaces of the YAG sheet ceramic layer. Compared with setting a ceramic layer on the top or bottom surface of the YAG sheet ceramic layer, the influence on the thermal conductivity of the YAG sheet ceramic layer is effectively reduced. The LuAG:Ce of the present application 3+ fluorescent glass thin film layer and (Sr,Ca)AlSiN3:Eu 2+ The fluorescent glass thin film layer has a relatively small influence on the thermal conductivity of the YAG sheet ceramic layer.

[0019] 3. The excitation source of the sandwich fluorescent structure of the present application is the blue light emitted by a 455 nm - 465 nm LED chip. The proposed sandwich structure fluorescent material can achieve high thermal conductivity and high-quality light emission. The thermal conductivity of the sandwich structure fluorescent material is 7 - 10 W / (m·K), the color rendering index is 92 - 96, and the relative color temperature is 4500 - 6000K. This material can be packaged with a blue light LED chip into a high-quality white light LED lighting device, which can be widely used in the fields of solid-state lighting and display. Description of the Drawings

[0020] In order to more clearly illustrate the embodiments of the present invention, the drawings required for describing the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 It is a schematic diagram of the sandwich fluorescent structure proposed by the present invention.

[0022] Figure 2 It is an XRD pattern of the green light emission layer in the sandwich fluorescent structure proposed by the present invention.

[0023] Figure 3 It is an XRD pattern of the red light emission layer in the sandwich fluorescent structure proposed by the present invention.

[0024] Figure 4 It is an electroluminescence spectrum of the sandwich fluorescent structure proposed by the present invention under blue light excitation.

[0025] Figure 5 It is a cross-sectional view of the white light LED lighting component proposed by the present invention.

[0026] In the figure, 1 is the main structure layer, 2 is the excitation source, 3 is the green light emission layer, 4 is the red light emission layer, 5 is the first heat sink, 6 is the second heat sink, 7 is the sandwich fluorescent structure, and 8 is the lid. Detailed Embodiments

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0028] Embodiment 1, a sandwich fluorescence structure, as Figure 1 and Figure 4 shown, includes a main structure layer 1. A green light emitting layer 3 is provided at the upper end of the main structure layer 1, and a red light emitting layer 4 is provided at the lower end. After the light source of the excitation source 2 is excited, it sequentially passes through the red light emitting layer 4, the main structure layer 1, and the green light emitting layer 3. The main structure layer 1 is a YAG sheet ceramic layer. In the sandwich fluorescence structure, the green light emitting layer 3, the YAG sheet ceramic layer, and the red light emitting layer 4 are arranged in sequence from top to bottom. The YAG sheet ceramic layer is arranged between the green light emitting layer 3 and the red light emitting layer 4, and the YAG sheet ceramic layer separates the green light emitting layer 3 and the red light emitting layer 4, avoiding the problem of multiple color light reabsorption and resulting in attenuation of the light emission intensity when the green light emitting layer 3 and the red light emitting layer 4 are closely arranged, and solving the technical problem in the prior art that the red fluorescent film and the green fluorescent ceramic in the lighting structure are closely arranged, resulting in multiple color light reabsorption and attenuation of the light emission intensity.

[0029] Embodiment 2, based on Embodiment 1, a sandwich fluorescence structure, as Figure 1 shown, the cross-section of the sandwich fluorescence structure is circular with a diameter of W, and the diameter of the light emitting surface of the blue LED chip is Z, where Z:W = 1.1 mm to 1.2 mm. Under the excitation of the blue LED, the red and green films respectively emit red light and green light, which are mixed with the unabsorbed blue light to obtain high-quality white light.

[0030] Embodiment 3, based on Embodiment 2, a sandwich fluorescence structure, as Figure 1 shown, the height of the YAG sheet ceramic layer is H, and 0.8 mm ≤ H ≤ 1.2 mm. When the height of the YAG sheet ceramic layer is between 0.8 mm and 1.2 mm, it is beneficial to the miniaturization of the entire sandwich fluorescence structure, and when the height of the YAG sheet ceramic layer is 1.2 mm, the thermal conductivity of the sandwich fluorescence structure is the highest.

[0031] Embodiment 4, based on Embodiment 3, a sandwich fluorescence structure, as Figure 1 and Figure 2 shown, the green light emitting layer 3 is a LuAG:Ce 3+ fluorescent glass thin film layer. The top surface of the YAG sheet ceramic layer is provided with LuAG:Ce 3+The fluorescent glass thin film layer effectively reduces the impact on the thermal conductivity of the YAG flake ceramic layer compared with setting a ceramic layer on the top surface of the YAG flake ceramic layer.

[0032] Example 5. On the basis of Example 4, a sandwich fluorescent structure, as Figure 1 , Figure 2 , Figure 3 shown, the red light emitting layer 4 is (Sr,Ca)AlSiN3:Eu 2+ fluorescent glass thin film layer. That is, thin film layers are provided on both the top surface and the bottom surface of the YAG flake ceramic layer. Compared with setting ceramic layers on the top surface and the bottom surface of the YAG flake ceramic layer, the impact on the thermal conductivity of the YAG flake ceramic layer is effectively reduced. The LuAG:Ce 3+ fluorescent glass thin film layer and the (Sr,Ca)AlSiN3:Eu 2+ fluorescent glass thin film layer of the present application have a relatively small impact on the thermal conductivity of the YAG flake ceramic layer.

[0033] Example 6. On the basis of Example 5, a sandwich fluorescent structure, Figure 2 and Figure 3 shown, the particle sizes of the (Sr,Ca)AlSiN3:Eu 2+ and LuAG:Ce 3+ are both between 200 nm and 250 nm. The thin film layer with particle sizes between 200 nm and 250 nm can reduce the pores inside the thin film, which is beneficial to the green light emitting layer 3 to emit green light and beneficial to the red light emitting layer 4 to emit red light, improving the quality of the obtained white light.

[0034] Example 7. On the basis of Example 6, a sandwich fluorescent structure, as Figure 2 and Figure 3 shown, the concentration ratio of the green light emitting layer 3 to the red light emitting layer 4 is Y, and 1.05 mm ≤ Y ≤ 1.2 mm. By varying the concentration ratio of the green light emitting layer 3 to the red light emitting layer 4, the color rendering index of the light source is regulated.

[0035] Example 8. On the basis of Example 7, a sandwich fluorescent structure, as Figure 1 and Figure 5 shown, the area ratio of the green light emitting layer 3 to the red light emitting layer 4 is X, and 1 mm ≤ X ≤ 1.05 mm. The larger the area ratio of the green light emitting layer 3 to the red light emitting layer 4, the higher the color rendering index, which is beneficial to obtaining high-quality white light.

[0036] Among them, preferably, the glass matrix particle sizes of both the green light emitting layer 3 and the red light emitting layer 4 are between 50 nm and 150 nm. With the glass matrix particle sizes both being between 50 nm and 150 nm, the internal pores in the thin films of the green light emitting layer 3 and the red light emitting layer 4 are reduced, which is beneficial to obtaining high-quality white light.

[0037] When Example 8 was implemented, the raw materials used for fabricating the sandwich fluorescent structure of the present application were all commercially available products, and the purity was greater than 99.9%. (Sr,Ca)AlSiN3:Eu 2+ and LuAG:Ce 3+ The particle size is between 200 nm and 250 nm. The glass matrix components are mixtures such as B2O3, α-Al2O3, ZnO, SiO2, etc., and the glass matrix particle size is between 50 nm and 150 nm.

[0038] Among them, the cross-sectional diameter of the sandwich fluorescent structure is W, and the diameter of the light-emitting surface of the blue LED chip is Z, where Z:W = 1.1 mm to 1.2 mm. Taking Z:W = 1.1, Z:W = 1.15, and Z:W = 1.2 as examples respectively.

[0039] The specific implementation steps are as follows: When the area ratio X of the upper green light emitting layer to the lower red light emitting layer is 1 and Z:W = 1.1, based on the total mass M of the mixed glass matrix and fluorescent powder, when the dosage of ethyl acetate is 2 times the total mass M of the powder, the dosage of terpineol is 1 time the total mass M of the powder, and the dosage of ethyl cellulose is 1 time the total mass M of the powder. Among them, the height H of the flaky YAG ceramic is 0.8 (unit: mm), the concentration ratio Y of the upper green light emitting layer to the lower red light emitting layer is 1.05, and when the area ratio X of the upper green light emitting layer to the lower red light emitting layer is 1.

[0040] (1) Add ethyl acetate, terpineol, and ethyl cellulose to the mixed glass matrix and fluorescent powder to obtain a gel-like material. Under the assistance of a mold, scrape and coat the red layer fluorescent material on the bottom surface of the YAG ceramic, and then dry it.

[0041] (2) For the single-sided dried green body, under the assistance of a mold, scrape and coat the green layer fluorescent material on the bottom surface of the YAG ceramic, and then dry it.

[0042] (3) Sinter the dried green body in an argon atmosphere, keep it at 120 o °C for 0.5 h, keep it at 400 o °C for 0.5 h. After the heat preservation ends, cool the sample to room temperature in a nitrogen atmosphere with the furnace. Heat it to 120 o °C at a heating rate of 0.5 o °C / min, and heat it to 400 o °C at a heating rate of 2 o °C to obtain the sandwich structure fluorescent material.

[0043] (4) When the obtained sandwich-structured fluorescent material is excited by a 455 nm blue LED, the color rendering index (CRI) of the light source obtained is 92, the correlated color temperature (CCT) is 4500 K, and at the same time, the thermal conductivity of the sandwich-structured fluorescent material is 11 W / (m·K).

[0044] When the area ratio X of the upper green light-emitting layer to the lower red light-emitting layer is 1 and Z:W = 1.15, based on the total mass M of the mixed glass matrix and fluorescent powder, the amount of ethyl acetate used is 2.5 times the total mass M of the powder, the amount of terpineol used is 1.2 times the total mass M of the powder, and the amount of ethyl cellulose is 1.5 times the total mass M of the powder. The height H of the flaky YAG ceramic is 1.0 (unit: mm). The concentration ratio Y of the upper green light-emitting layer to the lower red light-emitting layer is 1.1. The area ratio X of the upper green light-emitting layer to the lower red light-emitting layer is 1.01.

[0045] (1) Ethyl acetate, terpineol, and ethyl cellulose are added to the mixed glass matrix and fluorescent powder to obtain a gel-like material. The red light layer fluorescent material is scrape-coated on the bottom surface of the YAG ceramic with the assistance of a mold, and then dried.

[0046] (2) After the single-sided dried green body, the green light layer fluorescent material is scrape-coated on the bottom surface of the YAG ceramic with the assistance of a mold, and then dried.

[0047] (3) The dried green body is sintered in an argon atmosphere, held at 125 o °C for 0.8 h, held at 420 o °C for 0.7 h. After the holding ends, the sample is cooled to room temperature with the furnace in a nitrogen atmosphere. It is heated to 125 o °C at a heating rate of 0.8 o °C / min, and heated to 440 o °C at a heating rate of 2.5 o °C / min to obtain a sandwich-structured fluorescent material.

[0048] (4) When the obtained sandwich-structured fluorescent material is excited by a 460 nm blue LED, the color rendering index (CRI) of the light source obtained is 94, the correlated color temperature (CCT) is 5525 K, and at the same time, the thermal conductivity of the sandwich-structured fluorescent material is 10 W / (m·K).

[0049] When the ratio X of the area of the upper green light-emitting layer to the area of the lower red light-emitting layer is 1 and Z:W = 1.2, based on the total mass M of the mixed glass matrix and fluorescent powder, the dosage of ethyl acetate is 3 times the total mass M of the powder, the dosage of terpineol is 1.5 times the total mass M of the powder, and the dosage of ethyl cellulose is 2 times the total mass M of the powder. The height H of the flaky YAG ceramic is 1.2 (unit: mm). The ratio Y of the concentration of the upper green light-emitting layer to the concentration of the lower red light-emitting layer is 1.2. The ratio X of the area of the upper green light-emitting layer to the area of the lower red light-emitting layer is 1.05.

[0050] (1) Ethyl acetate, terpineol, and ethyl cellulose are added to the mixed glass matrix and fluorescent powder to obtain a gel-like material. The red light layer fluorescent material is scrape-coated on the bottom surface of the YAG ceramic with the assistance of a mold, and then dried.

[0051] (2) The single-sided dried green body is scrape-coated with the green light layer fluorescent material on the bottom surface of the YAG ceramic with the assistance of a mold, and then dried.

[0052] (3) The dried green body is sintered in an argon atmosphere, held at 130 o °C for 1 h, held at 450 o °C for 1 h. After the holding is completed, the sample is cooled to room temperature with the furnace in a nitrogen atmosphere. It is heated to 130 o °C at a heating rate of 1 o °C / min, and heated to 450 o °C at a heating rate of 3 o °C / min to obtain a sandwich-structured fluorescent material.

[0053] (4) When the obtained sandwich-structured fluorescent material is excited by a 465 nm blue LED, the color rendering index (CRI) of the obtained light source is 96, the correlated color temperature (CCT) is 6000 K, and at the same time, the thermal conductivity of the sandwich-structured fluorescent material is 7 W / (m·K).

[0054] Example 9, based on any one of Examples 1 to 8, a white LED lighting assembly, as Figure 5 shown, includes an excitation source 2, a first heat sink 5, a second heat sink 6, and the above-mentioned sandwich fluorescent structure 7. The excitation source 2 is a blue LED chip. The excitation source 2 is located between the first heat sink 5 and the second heat sink 6. A cover plate 8 is provided at the top of the first heat sink 5. The sandwich fluorescent structure 7 is located between the first heat sink 5 and the cover plate 8. The sandwich fluorescent structure 7 is directly above the excitation source 2. The settings of the first heat sink 5 and the second heat sink 6 are as Figure 5As shown, the first heat sink 5 and the second heat sink 6 are used to fix the excitation source 2 on the one hand and facilitate heat dissipation of the component on the other hand. The second heat sink 6 is provided with a first fixing groove. After the excitation source 2 is installed in the first groove of the second heat sink 6, the first heat sink 5 is used to press it. The top of the first heat sink 5 is provided with a second groove. After the sandwich fluorescent structure 7 is placed in the second groove, the sandwich fluorescent structure 7 is pressed and limited on the first heat sink 5 by the cover plate 8 to form the white LED lighting component of the present application. Among them, the cover plate 8, the first heat sink 5 and the second heat sink 6 can be respectively bonded and fixed.

[0055] Example 10, based on Example 9, a white LED lighting component, as Figure 1 , Figure 4 and Figure 5 shown, the emission wavelength of the excitation source 2 is 455 nm - 465 nm. When the emission wavelength of the excitation source is 455 nm - 465 nm, it is beneficial to excite the green light emitting layer 3 and the red light emitting layer 4, and improve the quality of the obtained white light.

[0056] When implementing Example 10, a first fixing groove is provided on the second heat sink 6, and a second groove is provided at the top of the first heat sink 5. After the excitation source 2 is installed in the first groove of the second heat sink 6, the first heat sink 5 is used to press it. After the above-mentioned sandwich fluorescent structure 7 is placed in the second groove, the sandwich fluorescent structure 7 is pressed and limited on the first heat sink 5 by the cover plate 8, and the white LED lighting component of the present application can be formed.

[0057] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A sandwich fluorescent structure, comprising a main structure layer (1), characterized in that: The upper end of the main structure layer (1) is provided with a green light emitting layer (3), and the lower end is provided with a red light emitting layer (4); after being excited by a light source, the light passes through the red light emitting layer (4), the main structure layer (1), and the green light emitting layer (3) in sequence; the main structure layer (1) is a YAG flaky ceramic layer.

2. The sandwich fluorescent structure according to claim 1, characterized in that: The cross section of the sandwich fluorescent structure is circular with a diameter of W, the diameter of the light emitting surface of the light source is Z, and Z:W=1.1mm~1.2mm.

3. The sandwich fluorescent structure according to claim 2, characterized in that: The height of the YAG flaky ceramic layer is H, 0.8 mm≤H≤1.2 mm.

4. The sandwich fluorescent structure according to claim 3, characterized in that: The green light emitting layer (3) is LuAG:Ce 3 + Fluorescent glass film layer.

5. The sandwich fluorescent structure according to claim 4, characterized in that: The red light emitting layer (4) is (Sr, Ca)AlSiN3:Eu 2+ Fluorescent glass film layer.

6. The sandwich fluorescent structure according to claim 5, characterized in that: The (Sr,Ca)AlSiN3:Eu 2+ and LuAG:Ce 3+ The particle size is between 200nm-250nm.

7. The sandwich fluorescent structure according to claim 6, characterized in that: The area ratio of the green light emitting layer (3) to the red light emitting layer (4) is X, 1≤X≤1.

05.

8. A white light LED lighting assembly, characterized in that: The invention comprises an excitation source (2), a first heat sink (5), a second heat sink (6) and a sandwich fluorescent structure (7) according to any one of claims 1 to 7, wherein the excitation source (2) is a blue light LED chip, the excitation source (2) is located between the first heat sink (5) and the second heat sink (6), a cover plate (8) is provided on the top of the first heat sink (5), the sandwich fluorescent structure (7) is located between the first heat sink (5) and the cover plate (8), and the sandwich fluorescent structure (7) is located directly above the excitation source (2).

9. The white light LED lighting assembly according to claim 8, characterized in that: The emission wavelength of the excitation source (2) is 455nm-465nm.

Images