Fluorescent diaphragm and LED packaging structure
By setting a stacked fluorescent layer structure in the fluorescent film, the problem of low excitation efficiency of red phosphor is solved, achieving high luminous efficiency and improved yield of LED products, and simplifying the packaging process.
Patent Information
- Application Number
- CN202422361880.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-26
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2034-09-26
AI Technical Summary
Existing fluorescent films have low excitation efficiency for red phosphors due to the mixing of phosphors with different excitation wavelengths on a single fluorescent layer, resulting in low luminous efficacy of LED products.
A stacked fluorescent layer structure is adopted, wherein the excitation wavelength of the fluorescent layer is successively shortened in the direction away from the red fluorescent layer, and multiple fluorescent layers, including a red fluorescent layer, a KSF fluorescent layer and a yellow-green fluorescent layer, are stacked through a release film. The peak wavelength stability and narrow half-wave peak of the KSF fluorescent layer are utilized to avoid light excitation loss.
It improves the luminous efficacy of LED products, reduces light excitation loss, enhances light display brightness and color consistency, increases manufacturing yield and phosphor utilization, and simplifies the packaging process.
Smart Images
Figure CN223666711U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of LED packaging, in particular to a fluorescent film and an LED packaging structure. BACKGROUND
[0002] The existing fluorescent film is a single-layer structure, which is a fluorescent colloid obtained by mixing red fluorescent powder, yellow-green fluorescent powder and silica gel, that is, fluorescent powders of different excitation wavelengths are mixed on a fluorescent layer. In processing, the segmented fluorescent film is fixed on a light-emitting chip by dipping silica gel, and the LED product is obtained by outer molding and glue sealing. However, the LED product processed by using the existing fluorescent film, after the blue light emitted by the light-emitting chip excites the yellow-green fluorescent powder in the mixed colloid, part of the yellow-green light will excite the red fluorescent powder at the same time, and since the wavelength of the yellow-green light is not within the excitation wavelength range of the red light, the excitation efficiency of the red fluorescent powder is low, resulting in low light efficiency of the LED product. CONTENT OF THE UTILITY MODEL
[0003] Therefore, the present application provides a fluorescent film and an LED packaging structure, which can reduce light excitation loss and improve the light efficiency of the LED product.
[0004] In order to achieve the above purpose, the present application provides the following technical scheme:
[0005] A fluorescent film includes at least two fluorescent layers stacked, the fluorescent layer includes a red fluorescent layer at the bottom layer, and the excitation wavelength of the fluorescent layer is sequentially shortened in the direction away from the red fluorescent layer.
[0006] Optionally, the fluorescent layer includes a KSF fluorescent layer, and the KSF fluorescent layer is arranged on one side of the red fluorescent layer.
[0007] Optionally, the red fluorescent layer is arranged as a KSF fluorescent layer.
[0008] Optionally, the outer periphery of the fluorescent layer is packaged with a white oil layer.
[0009] Optionally, the thickness of the fluorescent layer is sequentially increased in the direction away from the red fluorescent layer.
[0010] Optionally, the thickness of each fluorescent layer is arranged as 20-60 microns.
[0011] Optionally, the fluorescent layer includes a yellow-green fluorescent layer, and the KSF fluorescent layer is located between the red fluorescent layer and the yellow-green fluorescent layer.
[0012] Optionally, the thickness of the red fluorescent layer is arranged as 20-30 microns, the thickness of the yellow-green fluorescent layer is arranged as 50-60 microns, and the thickness of the KSF fluorescent layer is arranged as 35-45 microns.
[0013] Optionally, a release film is further included, which is attached to the bottom layer of the fluorescent layer.
[0014] Optionally, in the projection of the fluorescent layer in the stacking direction, the projection of the fluorescent layer is within the projection of the release film.
[0015] An LED packaging structure comprising the fluorescent film sheet as claimed in any one of the preceding items.
[0016] The fluorescent film sheet and the LED packaging structure provided by the present application can save the LED packaging color mixing work when packaging the LED product, and make the packaging work of the LED product more convenient. The light emitted by the light emitting chip in the LED product irradiates the multiple fluorescent layers in turn. The fluorescent layer close to the light emitting chip is excited first, and the fluorescent layer far from the light emitting chip is excited later. Since the light with longer wavelength is not easily absorbed by the fluorescent layer with shorter excitation wavelength, each fluorescent layer can be excited completely, the light excitation loss is reduced, and the light efficiency of the LED product is improved. BRIEF DESCRIPTION OF DRAWINGS
[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by the drawings provided by the person skilled in the art without creative labor.
[0018] Figure 1 The structure of each layer of the fluorescent film sheet shown in some embodiments Figure 1
[0019] Figure 2 The structure of each layer of the fluorescent film sheet shown in some embodiments Figure 2
[0020] Figure 3 The structure of each layer of the fluorescent film sheet shown in some embodiments Figure 3
[0021] In the figure: 1, release film; 2, red fluorescent layer; 3, KSF fluorescent layer; 4, yellow-green fluorescent layer. DETAILED DESCRIPTION
[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.
[0023] As shown in the drawings, Figures 1-3 The present application provides a fluorescent film, which comprises a release film 1 and a plurality of fluorescent layers stacked. The plurality herein refers to two or more, that is, there are at least two fluorescent layers stacked. The number of layers of the fluorescent layers can be two, three or four or more, depending on actual needs. The plurality of fluorescent layers has a bottom layer and a surface layer. When packaging an LED product, the bottom layer of the plurality of fluorescent layers is fixed on a light-emitting chip by dipping silicone glue, and the LED product is obtained by external molding. In this way, the use of prefabricated fluorescent film can save the LED packaging color adjustment work, making the packaging work of the LED product more convenient.
[0024] The plurality of fluorescent layers comprises a red fluorescent layer 2 at the bottom layer, and the excitation wavelength of the plurality of fluorescent layers is shortened in the direction from the bottom layer to the surface layer, that is, in the two adjacent fluorescent layers, the excitation wavelength of the fluorescent layer closer to the bottom layer is longer than that of the fluorescent layer closer to the surface layer. The excitation wavelength of the fluorescent layer at the bottom layer (red fluorescent layer 2) is the longest, and the excitation wavelength of the fluorescent layer at the surface layer is the shortest. In the LED product made of the present fluorescent film, the light emitted by the light-emitting chip irradiates the plurality of fluorescent layers in turn. The fluorescent layer (red fluorescent layer 2) close to the light-emitting chip has a longer excitation wavelength and is excited first, and the fluorescent layer far from the light-emitting chip has a shorter excitation wavelength and is excited later. Since the light with a longer wavelength is not easily absorbed by the fluorescent layer with a shorter excitation wavelength, each layer of the fluorescent layer can be fully excited, reducing the light excitation loss, that is, reducing the loss of red fluorescent powder excited by yellow-green light, and improving the light efficiency of the LED product.
[0025] It should be noted that the present fluorescent film is a whole product and can be used alone for packaging of an LED product, that is, the LED product is packaged in the form of pre-processing of the fluorescent film. Compared with the processing method of glue dispensing or fluorescent glue spraying in the traditional technology, the LED product made of the present fluorescent film has better light color consistency and more concentrated landing points, which is conducive to improving the manufacturing yield of the LED product. Moreover, the utilization rate of the fluorescent powder and the silicone glue can be effectively improved, and the waste of the fluorescent powder and the silicone glue can be reduced.
[0026] The fluorescent film sheet also comprises a release film 1, the release film 1 and the plurality of fluorescent layers are stacked along the thickness direction of the release film 1, and the release film 1 is connected with the bottom fluorescent layer, for example, the release film 1 is detachably connected with the bottom fluorescent layer, so as to facilitate use in subsequent packaging process. In the preparation process, a plurality of fluorescent layers are sequentially stacked on the side of the release film 1 to form the fluorescent film sheet product. When packaging the LED product, the release film 1 in the fluorescent film sheet is torn off, and the side of the plurality of fluorescent layers close to the release film 1 is fixed on the light-emitting chip by dipping silicone glue, and the LED product is obtained by outer molding and gluing. In this way, after processing with the release film, the structural strength of the fluorescent film sheet can be maintained during transportation and storage, and the product reliability is improved.
[0027] Moreover, in the projection of the thickness direction of the release film 1 (i.e. the stacking direction of the plurality of fluorescent layers), the projection of the plurality of fluorescent layers is within the projection of the release film 1, that is, the area of the release film 1 is greater than the area of the fluorescent layer. For example, the bottom fluorescent layer is attached to the middle part of the release film 1, which is beneficial for tearing off the release film 1 during use, thereby improving the processing efficiency and use convenience.
[0028] In the present scheme, each fluorescent layer is formed by mixing fluorescent powder and transparent silicone glue, and the wavelength of the mixed fluorescent glue can be adjusted by adjusting the parameters of the fluorescent powder, such as the color and concentration of the fluorescent powder. Specifically, the wavelength of the fluorescent glue mixed by red fluorescent powder and transparent silicone glue is greater than the wavelength of the fluorescent glue mixed by yellow-green fluorescent powder and transparent silicone glue. The wavelength of the fluorescent glue mixed by fluorescent powder with high concentration and transparent silicone glue is greater than the wavelength of the fluorescent glue mixed by fluorescent powder with low concentration and transparent silicone glue.
[0029] Here, the concentration of the fluorescent powder is set to 69%-73%, which can make the surface of the fluorescent film smooth. The specific concentration of the fluorescent powder depends on the color coordinate adjustment, but the concentration of the fluorescent powder should not be too high, otherwise it will cause uneven distribution of the fluorescent powder in the silicone glue.
[0030] In some embodiments, the thickness of the plurality of fluorescent layers increases in the direction away from the red fluorescent layer 2, that is, in the two adjacent fluorescent layers, the thickness of the fluorescent layer relatively close to the bottom layer is less than the thickness of the fluorescent layer relatively close to the surface layer. In this way, within a certain range of the concentration of the fluorescent powder, the light color of the LED product can be adjusted by adjusting the thickness of each fluorescent layer.
[0031] It should be noted that different LED products require different formulations of fluorescent powder when adjusting the light, different proportions of fluorescent powder of different colors, and different amounts of fluorescent powder of different colors, which in turn determines the different thicknesses of each fluorescent layer.
[0032] Here, the thickness of the fluorescent layer is set to 20-60 microns, and the thickness of the fluorescent powder is adjusted according to the color coordinate of the light, but the thickness of the fluorescent powder should not be too low, otherwise it will lead to uneven distribution of the fluorescent powder in the transparent silicone. Among them, if the thickness of the fluorescent layer is less than 20 microns, the content of the transparent silicone is very small during processing, which makes the fluorescent layer unable to be shaped, and it cannot be peeled off from the release film; if the thickness of the fluorescent layer is greater than 60 microns, since the fluorescent powder is generally made of ceramic particles, the ceramic particles are easy to absorb heat, which is not conducive to heat dissipation, resulting in heat accumulation.
[0033] Of course, in other embodiments, the thickness of each fluorescent layer can also be kept consistent, which is conducive to ensuring the consistency of the structure. When preparing, the color difference and concentration difference of the fluorescent powder are adjusted to make the adjacent fluorescent layers have a wavelength difference.
[0034] In this scheme, the plurality of fluorescent layers includes a KSF fluorescent layer 3, the KSF fluorescent layer 3 is mixed from KFS fluorescent powder and transparent silicone, and the wavelength of the KSF fluorescent layer 3 is about 600 nanometers, which can be excited by the light-emitting chip to emit red light.
[0035] In the first embodiment, as shown in Figures 1-2 , the KSF fluorescent layer 3 is independent of the red fluorescent layer 2, and the KSF fluorescent layer 3 is arranged on one side of the red fluorescent layer 2. Since the red fluorescent layer 2 is located at the bottom layer of the plurality of fluorescent layers, the KSF fluorescent layer 3 is located on the side of the red fluorescent layer 2 close to the surface layer, that is, the KSF fluorescent layer 3 is located between the bottom layer and the surface layer of the plurality of fluorescent layers. Here, the red fluorescent layer 2 can be set to a nitride material different from the KSF fluorescent layer 3 or other materials. In addition to the KSF fluorescent layer 3 and the red fluorescent layer 2, the fluorescent layer located on the surface layer can be provided with one layer, or two or more layers, which are stacked on the side of the KSF fluorescent layer 3 away from the red fluorescent layer 2.
[0036] In the second embodiment, as shown in Figure 3 , since the KSF fluorescent layer 3 can excite red light, the red fluorescent layer 2 is set to the KSF fluorescent layer 3, that is, the red fluorescent layer 2 is composed of KSF fluorescent powder, and the red fluorescent layer 2 and the KSF fluorescent layer 3 are the same layer.
[0037] Because the KSF fluorescent powder has the characteristics of stable peak wavelength and narrow half-wave peak, compared with the traditional nitride red fluorescent powder, when the KSF fluorescent powder is matched with the green fluorescent powder of the same wave band, the multiple fluorescent layers with the KSF fluorescent powder have higher excitation index, and the secondary light reabsorption is reduced. Under the same excitation conditions, the brightness of the multiple fluorescent layers with the KSF fluorescent powder is also higher. Moreover, the KSF fluorescent powder has certain hygroscopicity and is easy to react with the water vapor in the air when the temperature rises. Placing the KSF fluorescent powder in the bottom layer or the middle layer of the multiple fluorescent layers can avoid the contact between the KSF fluorescent layer 3 and the water vapor in the air, achieve the purpose of isolating the water vapor and the air, prevent the KSF fluorescent powder from being damp and invalid, ensure the effectiveness of the KSF fluorescent powder, and further improve the excitation index.
[0038] Specifically, the white oil layer can be packaged on the outer periphery of the multiple fluorescent layers, and the LED packaging process can be matched to completely isolate the KSF fluorescent powder from the water vapor.
[0039] It should be noted that KSF is the abbreviation of the chemical formula K2SiF6:Mn4+, which can be called (contains tetravalent manganese ion) potassium fluorosilicate in Chinese. It is also often called fluoride fluorescent powder in the packaging industry. In a strict sense, KSF refers to a type of compound containing A2(MF6):Mn4+ structural formula formula, wherein A is one of Li, Na, K, Rb, Cs, NH4, and M is one of Ge, Si, Sn, Ti, Zr elements, or an element combination.
[0040] In some preferred schemes, as shown in Figure 1 The fluorescent layer is provided with three layers, including a red fluorescent layer 2, a yellow-green fluorescent layer 4 and a KSF fluorescent layer 3. The excitation wavelength of the KSF fluorescent layer 3 is less than that of the red fluorescent layer 2 and greater than that of the yellow-green fluorescent layer 4. The KSF fluorescent layer 3 is between the red fluorescent layer 2 and the yellow-green fluorescent layer 4. For example, the red fluorescent layer 2 is made of red fluorescent powder and transparent silicone. In this way, the fluorescent layer is provided with three layers, which can simplify the structure, facilitate processing, and also improve the light intensity of the manufactured LED product.
[0041] The red fluorescent layer 2 is made of red fluorescent powder and transparent silicone, and the thickness of the red fluorescent layer 2 is set to 20-30 microns, preferably 25 microns. The yellow-green fluorescent layer 4 is made of yellow-green fluorescent powder and transparent silicone, and the thickness of the yellow-green fluorescent layer 4 is set to 50-60 microns, preferably 55 microns. The KSF fluorescent layer 3 is made of KSF fluorescent powder and transparent silicone, and the thickness of the KSF fluorescent layer 3 is set to 35-45 microns, preferably 40 microns. In this way, by designing the wavelength and thickness of each layer of the fluorescent layer, excitation loss between adjacent layers of the fluorescent layer can be avoided, which is conducive to improving the light brightness.
[0042] Specifically, the thickness of the red fluorescent layer 2 is set to 25 microns; the thickness of the yellow-green fluorescent layer 4 is set to 55 microns; and the thickness of the KSF fluorescent layer 3 is set to 40 microns. In this way, the thickness of the fluorescent film can be prevented from being too large to affect the heat dissipation of the LED product, and the thickness of each fluorescent layer can be set to reasonably distribute the proportions of the fluorescent powders of each color, so that the color coordinates can be ensured to be within a reasonable range.
[0043] The processing technology of the fluorescent film will be described in detail below according to the above embodiment.
[0044] The various fluorescent powders are mixed with transparent silicone to form fluorescent glue. Specifically, the red fluorescent powder is mixed with transparent silicone to form red fluorescent glue; the yellow-green fluorescent powder is mixed with transparent silicone to form yellow-green fluorescent glue; and the KSF fluorescent powder is mixed with transparent silicone to form KSF fluorescent glue.
[0045] The red fluorescent glue prepared from the red fluorescent powder with the longest wavelength is placed on the release film 1 and is uniformly scraped flat to form a red fluorescent layer 2 with a film thickness of 25 microns. The red fluorescent layer 2 is subjected to high temperature of 150±10 degrees Celsius to be cured to form the bottom layer of the multiple fluorescent layers.
[0046] The KSF fluorescent glue prepared from the KSF fluorescent powder is placed on the cured red fluorescent layer 2 and is uniformly scraped flat to form a KSF fluorescent layer 3 with a film thickness of 40 microns. The KSF fluorescent layer 3 is subjected to high temperature of 150±10 degrees Celsius to be cured to form the middle layer of the multiple fluorescent layers.
[0047] The yellow-green fluorescent glue prepared from the yellow-green fluorescent powder with the shortest wavelength is placed on the cured KSF fluorescent glue and is uniformly scraped flat to form a yellow-green fluorescent layer 4 with a film thickness of 55 microns. The yellow-green fluorescent layer 4 is subjected to high temperature of 150±10 degrees Celsius to be cured to form the surface layer of the multiple fluorescent layers.
[0048] The multiple fluorescent layers and the release film 1 are cut according to the required size to form separate fluorescent films, which are carried by a blue film for standby. The concentration of the fluorescent powder in each fluorescent layer is 69%-73%.
[0049] The embodiment of the present application provides an LED packaging structure comprising the fluorescent film in the above embodiment, which has the characteristics of convenient processing, high yield, and high light efficiency.
[0050] The above describes the basic principles of the present application in combination with specific embodiments, but it should be noted that the advantages, benefits, effects and the like mentioned in the present application are only examples and are not limiting, and these advantages, benefits, effects and the like cannot be considered as necessary for each embodiment of the present application. In addition, the above specific details disclosed are only for the purpose of illustration and understanding, and are not limiting, and the above details do not limit the present application to be necessarily implemented with the above specific details.
[0051] The block diagrams of the devices, apparatuses, equipment, systems involved in the present application are only illustrative examples and are not intended to require or imply the connection, arrangement, configuration shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, equipment, systems can be connected, arranged, configured in any manner. Words such as "include", "contain", "have" and the like are open-ended words, mean "including but not limited to", and can be used interchangeably. The words "or" and "and" used herein mean the word "and / or", and can be used interchangeably unless the context clearly indicates otherwise. The word "such as" used herein means the phrase "such as but not limited to", and can be used interchangeably.
[0052] It should also be noted that in the devices, equipment and methods of the present application, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be considered as equivalent solutions of the present application.
[0053] The above description of the disclosed aspects is provided so that any person skilled in the art can make or use the present application. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but is intended to be accorded the widest scope consistent with the principles and novel features disclosed herein.
[0054] It should be understood that the limiting words "first", "second", "third", "fourth", "fifth" and "sixth" used in the description of the embodiments of the present application are only used for clearer description of the technical solutions, and cannot be used to limit the protection scope of the present application.
[0055] The above description has been given for the purpose of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although the above has discussed the multi-layer example aspects and embodiments, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.
Claims
1. A fluorescent film sheet, characterized by, The fluorescent film comprises at least two fluorescent layers arranged in a stack, wherein the fluorescent layers comprise a red fluorescent layer (2) at the bottom layer, the excitation wavelength of the fluorescent layers is sequentially shortened in a direction away from the red fluorescent layer (2), and the thickness of the fluorescent layers is sequentially increased in the direction away from the red fluorescent layer (2).
2. The fluorescent film sheet according to claim 1, characterized by The fluorescent layers comprise a KSF fluorescent layer (3) arranged on one side of the red fluorescent layer (2).
3. The fluorescent film sheet according to claim 1, characterized by The red fluorescent layer (2) is arranged as a KSF fluorescent layer (3).
4. The fluorescent film sheet according to claim 2 or 3, characterized by The outer periphery of the fluorescent layers is encapsulated by a white oil layer.
5. The fluorescent film sheet according to claim 1, wherein The thickness of each of the fluorescent layers is arranged to be 20-60 microns.
6. The fluorescent film sheet according to claim 2, characterized by The fluorescent layers comprise a yellow-green fluorescent layer (4), and the KSF fluorescent layer (3) is arranged between the red fluorescent layer (2) and the yellow-green fluorescent layer (4).
7. The fluorescent film sheet according to claim 6, characterized by The thickness of the red fluorescent layer (2) is arranged to be 20-30 microns, the thickness of the yellow-green fluorescent layer (4) is arranged to be 50-60 microns, and the thickness of the KSF fluorescent layer (3) is arranged to be 35-45 microns.
8. The fluorescent film sheet according to claim 1, characterized by A release film (1) is further included, and the release film (1) is attached to the bottom layer of the plurality of fluorescent layers.
9. The fluorescent film sheet according to claim 8, characterized by In the projection of the fluorescent layers in the stacking direction, the projection of the fluorescent layers is within the projection of the release film (1).
10. An LED package structure, characterized in that, The fluorescent film comprises the fluorescent film piece according to any one of claims 1-9.