LED packaging structure, LED module and lighting device
By reasonably setting the phosphor layer and heat insulation layer in the LED packaging structure, the problem of light and color inconsistency is solved, and the color rendering effect is improved and the color rendering index maintained under high power density is achieved.
Patent Information
- Application Number
- CN202421220150.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-30
- Publication Date
- 2025-05-09
- Estimated Expiration
- 2034-05-30
AI Technical Summary
The existing LED packaging structure is prone to inconsistent light and color, resulting in poor color rendering effect.
By reasonably setting the phosphor layer, including using yellow-green phosphor and red phosphor, and setting an insulating layer between the LED chip and the phosphor layer, the thickness of the phosphor layer is controlled to be between 70um and 80um.
It improves the light and color consistency of the LED packaging structure, has good color rendering effect, and maintains a high color rendering index under high power density.
Smart Images
Figure CN222852588U_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present invention relate to the field of LED technology, and more particularly to an LED packaging structure, an LED module and a lighting device. Background Art
[0002] At present, LED packaging structures usually use blue light LED chips as light sources, and set a phosphor layer on the surface of the blue light LED chip. The light emitted by the phosphor in the phosphor layer after being excited is mixed with the blue light to produce white light.
[0003] In the related art, the phosphor layer is usually made of yellow phosphor, and the thickness of the phosphor layer can range from tens of microns to hundreds of microns. However, the LED packaging structure is prone to inconsistent light color and poor color rendering effect. Utility Model Content
[0004] In view of this, multiple embodiments of this specification are dedicated to providing an LED packaging structure, an LED module and a lighting device, which can improve the light color consistency of the LED packaging structure to a certain extent and achieve better color rendering effect by reasonably setting the phosphor layer.
[0005] One embodiment of the present specification provides an LED packaging structure, comprising: a substrate; an LED chip, wherein the LED chip is mounted on the substrate; and a phosphor layer, wherein the phosphor layer is arranged on a side of the LED chip away from the substrate; wherein the phosphor layer is made of yellow-green phosphor and red phosphor, and the thickness of the phosphor layer is greater than 70um and not more than 80um.
[0006] Optionally, a heat insulation layer is further provided between the LED chip and the phosphor layer.
[0007] Optionally, the heat insulation layer is made of a transparent glass sheet.
[0008] Optionally, the thickness of the transparent glass sheet is not less than 0.5 mm.
[0009] Optionally, an adhesive layer is further provided between the transparent glass sheet and the LED chip; the thickness of the adhesive layer does not exceed 5 um.
[0010] Optionally, the LED packaging structure further includes a light-shielding adhesive layer disposed on the substrate; the light-shielding adhesive layer is disposed around the LED chip.
[0011] Optionally, the thickness of the light-shielding adhesive layer is greater than the maximum height of the LED chip relative to the substrate, and does not exceed the maximum height of the heat-insulating layer relative to the substrate.
[0012] Optionally, the LED chip is a blue light chip or a purple light chip.
[0013] Optionally, a pattern layer is provided on the surface or inside of the transparent glass sheet.
[0014] An embodiment of the present specification further provides an LED module, comprising the LED packaging structure described in any of the aforementioned embodiments.
[0015] One embodiment of the present specification further provides a lighting device, comprising the LED packaging structure or LED module described in any of the aforementioned embodiments.
[0016] The multiple implementations provided in this specification can improve the light color consistency of the LED packaging structure to a certain extent by reasonably setting the phosphor layer, and the color rendering effect is better. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 A cross-sectional schematic diagram of an LED packaging structure provided in one embodiment of this specification.
[0018] Figure 2 A cross-sectional schematic diagram of an LED packaging structure provided in another embodiment of the present specification. DETAILED DESCRIPTION
[0019] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with 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.
[0020] In the description of the embodiments of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.
[0021] In the related art, the white light LED packaging structure usually includes an LED blue light chip, and a phosphor layer arranged on the surface of the LED blue light chip. The phosphor layer is usually made of yellow phosphor (such as yttrium aluminum garnet YAG:Ce). Specifically, the phosphor layer can be formed by evenly dispersing the yellow phosphor in a colloid such as silica gel and epoxy resin, and coating the colloid doped with yellow phosphor on the surface of the LED blue light chip. The coating thickness is usually in the range of tens of microns to hundreds of microns. When the LED blue light chip emits light to the phosphor layer, the yellow phosphor in the phosphor layer absorbs part of the blue light energy and re-radiates yellow light, which mixes with the blue light to produce a white light effect.
[0022] However, technicians have found that the LED packaging structure in the related art is prone to inconsistent light color, resulting in poor overall color rendering. This is mainly due to the unreasonable setting of the phosphor layer, including the choice of phosphor color and the thickness of the phosphor layer. For example, if the thickness of the phosphor layer is set too thick, the absorption and scattering of the excitation light by the phosphor particles will be enhanced, which will not only lead to the loss of luminous flux, but also may make the phosphor in some areas unable to be effectively excited, thereby causing uneven light emission and differences in light color. If the thickness of the phosphor layer is set too thin, the uneven distribution of phosphor particles will also lead to inconsistent light color.
[0023] Therefore, it is necessary to provide an LED packaging structure that can improve the light color consistency to a certain extent by reasonably setting the phosphor layer, so that the LED packaging structure has a better color rendering effect.
[0024] See also Figure 1 An LED packaging structure provided in one embodiment of the present specification includes a substrate 11 , an LED chip 12 , a phosphor layer 13 , and a light shielding adhesive layer 17 .
[0025] The substrate 11 can be used to carry the LED chip 12 and provide power drive for the LED chip 12. Specifically, the substrate 11 can be made of different materials according to different requirements. For example, the substrate 11 can be a printed circuit board (PCB) suitable for low-power LEDs, or a metal substrate suitable for medium- and high-power LEDs, such as an aluminum substrate, or a ceramic substrate, such as an Al2O3 ceramic substrate, an AlN ceramic substrate, or a BeO ceramic substrate.
[0026] The LED chip 12 can be used as a core semiconductor element in the LED package structure to generate light, and is used to convert electrical energy into light energy. When the LED package structure is working, when current passes through the LED chip 12, electrons and holes recombine in the PN junction region, release energy and emit in the form of photons, thereby achieving light emission. In this embodiment, the LED chip 12 can be a blue light chip or a purple light chip.
[0027] The LED chip 12 can be mounted on the substrate 11. Specifically, for example, the LED chip 12 can be fixedly bonded to the substrate 11 by die bonding, or can be fixed to the substrate 11 by welding. This specification does not limit the specific mounting method.
[0028] The light shielding adhesive layer 17 is disposed on the substrate 11 and surrounds the LED chip 12 to form a wrap around the LED chip 12. The light shielding adhesive layer 17 can be used to block side light to prevent light crosstalk, and can also be used to isolate and protect the LED chip 12. The light shielding adhesive layer 17 can be made of light shielding adhesive, and specifically, the material of the light shielding adhesive can be polyethylene terephthalate, acrylic esters, epoxy resin, etc.
[0029] The phosphor layer 13 is used to absorb part of the energy of the blue light or purple light emitted by the LED chip 12, convert it into light with a longer wavelength, and combine it with the remaining blue light or purple light to form white light perceived by the human eye through spectrum superposition and balance.
[0030] The phosphor layer 13 may be disposed on the side of the LED chip 12 away from the substrate 11. Specifically, the phosphor layer 13 may be directly disposed on the surface of the LED chip 12 away from the substrate 11, and may be disposed by printing, coating, powder spraying, etc. In some embodiments, the surface of the LED chip 12 away from the substrate 11 may be further provided with other structures, such as a silicone layer, an air layer, etc., and the phosphor layer 13 may also be disposed on the surface of these structures.
[0031] In this embodiment, the phosphor layer 13 can be made of yellow-green phosphor and red phosphor. Specifically, the yellow-green phosphor and the red phosphor can be mixed with a transparent colloid (such as silica gel or other resin), and then the mixed colloid is applied to the surface of the LED chip 12 or the surface of other structures set on the side of the LED chip 12 away from the substrate 11 to form the phosphor layer 13. Of course, a mixture of yellow-green phosphor and red phosphor can also be used to make the phosphor layer 13 by spraying, printing, etc. For example, an electrostatic spraying process can be used to make the phosphor mixture adhere to the surface of the LED chip 12 or the surface of other structures set on the side of the LED chip 12 away from the substrate 11, and then cured by heat treatment to form the phosphor layer 13.
[0032] In this embodiment, the thickness T of the phosphor layer 13 is greater than 70um and does not exceed 80um. Specifically, for example, the thickness T of the phosphor layer 13 can be 75um, or 78um or 80um. Since the particle size of the yellow phosphor is between 20 and 25um, by reasonably controlling the thickness T of the phosphor layer between 70 and 80um, it can be ensured that the phosphor particles in the phosphor layer are stacked in 4 to 5 particles, avoiding the uneven phosphor phenomenon due to the small number of phosphor particles, ensuring the consistency of light color, and also having a higher color rendering index. For example, according to the test results of technicians, for the color temperature requirements above 5000K, the LED packaging structure provided in this embodiment can have a better color rendering effect.
[0033] However, technicians have further discovered that when the power density of the LED chip 12 is high, the luminous effect of the LED packaging structure provided in the above embodiment will be poor. The reason is that when the power density of the LED chip 12 is high, the LED packaging structure will generate a lot of heat in the working state, causing the phosphor layer 13 to turn yellow and black due to excessive temperature, thereby affecting the light extraction efficiency.
[0034] To solve the above problem, technicians tried to use a ceramic fluorescent film (phosphor inglass, PIG) with high heat resistance as the phosphor layer 13, but found that the color rendering index achieved was low. This is mainly because the ceramic fluorescent film is formed by high-temperature sintering, and the sintering temperature is usually over 800°C. Since the red phosphor has poor mechanical properties, low hardness and high brittleness at high temperatures, it is difficult to sinter the red phosphor, making it difficult for the ceramic fluorescent film to achieve a high color rendering index.
[0035] See also Figure 2 Another embodiment of the present specification provides an LED packaging structure, comprising a substrate 11, an LED chip 12, a phosphor layer 13, a heat insulation layer 15, an adhesive layer 16 and a light shielding layer 17. Figure 1 The LED packaging structure shown is different in that it further includes a heat insulation layer 15 and an adhesive layer 16 .
[0036] In some embodiments, a heat insulating layer 15 may be provided between the LED chip 12 and the phosphor layer 13. The heat insulating layer 15 is used to isolate the phosphor layer 13 from the LED chip 12, and reduce the heat transferred from the LED chip 12 to the phosphor layer 13. Specifically, the heat insulating layer 15 may be made of a high temperature resistant material, such as a ceramic sheet, a silica aerogel, and the like.
[0037] The phosphor layer 13 can be formed on the surface of the heat insulating layer 15 away from the substrate. Specifically, a mixture of yellow-green phosphor and red phosphor can be coated on the surface of the heat insulating layer 15 by printing, coating, powder spraying, etc. to form the phosphor layer 13.
[0038] By setting the heat insulation layer 15 between the LED chip 12 and the phosphor layer 13, the yellowing and blackening phenomenon of the phosphor layer 13 at high temperature can be reduced, and the luminous efficiency can be improved. In addition, unlike the ceramic fluorescent film, the phosphor layer 13 is made directly on the surface of the heat insulation layer, so the red phosphor does not need to be sintered at high temperature, so that the phosphor layer 13 is mixed with red phosphor with better performance. In this way, when using a high-power density LED chip 12, a higher color rendering index can also be achieved, which can solve the problem of poor color rendering performance of existing high-power ceramic fluorescent film products due to the difficulty in sintering red phosphor.
[0039] In some embodiments, the heat insulating layer 15 may be made of a transparent glass sheet. Since transparent glass has a high light transmittance, it blocks less light emitted by the LED chip 12, and has a high high temperature resistance, so using a transparent glass sheet as the heat insulating layer 15 has a good effect on improving the light extraction efficiency and the color rendering index.
[0040] Optionally, a pattern layer may be provided on the surface or inside of the transparent glass sheet so that the light emitted by the LED package structure can achieve a pattern effect. Specifically, for example, a desired pattern or microstructure may be formed on the surface or inside of the transparent glass sheet by laser etching or chemical etching, thereby affecting the transmission and scattering of light to achieve a specific light emission pattern. In some embodiments, a fluorescent material or other optical medium may be directly printed on the surface of the transparent glass sheet to form a pattern.
[0041] In some embodiments, optionally, the thickness of the transparent glass sheet is not less than 0.5 mm. Specifically, for example, the thickness of the transparent glass sheet can be set to 0.5 mm, or 0.8 mm, or can also be set to 1 mm.
[0042] If the thickness of the transparent glass sheet is less than 0.5 mm, it is easy to break or shatter during the die bonding process. Therefore, setting the thickness of the transparent glass sheet to not less than 0.5 mm can improve the stability and reliability of the LED packaging structure.
[0043] In some embodiments, optionally, an adhesive layer 16 is further provided between the transparent glass sheet and the LED chip. The adhesive layer 16 is used to bond and fix the transparent glass sheet to the LED chip 12. Specifically, the adhesive layer 16 can be made of adhesive, and the adhesive can be organic silicone, epoxy resin adhesive, UV curing adhesive, etc., which is not specifically limited in this specification.
[0044] Optionally, the thickness of the adhesive layer 16 does not exceed 5 um. Specifically, for example, the thickness of the adhesive layer 16 may be 2 um, or 4 um or 5 um.
[0045] If the thickness of the adhesive layer 16 is too thick, it may affect the transmittance of light and reduce the light extraction efficiency and uniformity. By setting the thickness of the adhesive layer 16 to no more than 5um, the light extraction efficiency and uniformity can be improved. In addition, if the thickness of the adhesive layer 16 is too thick, it will also hinder the effective conduction of heat and affect the heat dissipation performance of the LED chip 12. By setting the thickness of the adhesive layer 16 to no more than 5um, the thermal stability of the LED chip 12 can be guaranteed and the service life can be improved.
[0046] In some embodiments, optionally, the thickness d of the light shielding adhesive layer 17 is greater than the maximum height h1 of the LED chip 12 relative to the substrate, and does not exceed the maximum height h2 of the heat insulation layer 15 relative to the substrate 11 .
[0047] In this way, on the one hand, a larger range of isolation and protection can be formed for the LED chip 12; on the other hand, the filling thickness d does not exceed the maximum height h2 of the thermal insulation layer 15 relative to the substrate 11, so that the light emission of the phosphor layer 13 arranged on the thermal insulation layer 15 is not blocked, thereby improving the light output efficiency.
[0048] In some embodiments, before setting the phosphor layer, a light shielding adhesive layer 17 may be filled around the LED chip 12 , and then the light shielding adhesive layer 17 may be polished to be flush with the insulation layer 15 , and finally the phosphor layer 13 may be made on the surface of the insulation layer 15 .
[0049] The embodiments of the present specification may also provide an LED packaging structure, which may include: a substrate with an LED chip mounted thereon; a red phosphor layer disposed on the light-emitting side of the LED chip; wherein a yellow-green fluorescent glass sheet is also disposed between the LED chip and the red phosphor layer.
[0050] In this embodiment, a red phosphor layer can be made on the surface of the yellow-green fluorescent glass by printing, coating, powder spraying, etc. In this way, the problem that the ceramic fluorescent film is difficult to sinter the red phosphor can be avoided. While the yellow-green fluorescent glass provides a heat insulation effect, the red phosphor layer can also ensure a color rendering effect. This LED packaging structure can also achieve a higher color rendering index when using a high-power density LED chip.
[0051] The embodiments of the present specification may provide an LED module, including an LED packaging structure as in any of the aforementioned embodiments. The LED module may be used as a component unit of an LED display screen or a lighting device. Specifically, the LED module may also include a control unit, a drive circuit, and electronic components with current limiting, filtering, and other functions. In some embodiments, the LED module may also include other components, such as a polarizing plate, a CF layer, a TFT layer, and the like.
[0052] The embodiments of this specification may also provide a lighting device, including an LED packaging structure or an LED module as in any of the aforementioned embodiments. The lighting device may also include optical components, such as lenses, reflectors, etc., or mounting structures, such as hangers, suspension devices, mounting brackets, etc. Specifically, the lighting device may include lighting fixtures, such as LED filaments, LED light strips, LED special-shaped lights, safety indicator lights, mining lamps, etc., and may also include automotive LED lights, such as position lights, brake lights, turn signals, daytime running lights, atmosphere lights, etc.
[0053] It should be understood that the specific examples herein are only intended to help those skilled in the art to better understand the embodiments of the present specification, rather than to limit the scope of the present invention.
[0054] It can be understood that in the various implementations of this specification, the size of the sequence number of each process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the implementation methods of this specification.
[0055] It can be understood that the various embodiments described in this specification can be implemented individually or in combination, and the embodiments of this specification are not limited to this.
[0056] Unless otherwise specified, all technical and scientific terms used in the embodiments of this specification have the same meaning as those generally understood by those skilled in the art of the technical field of this specification. The terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit the scope of this specification. The term "and / or" used in this specification includes any and all combinations of one or more related listed items. The singular forms of "a", "above", and "the" used in the embodiments of this specification and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.
[0057] The above is only a specific implementation of this specification, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in this specification, which should be included in the protection scope of this specification. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.
Claims
1. An LED packaging structure, characterized in that: include: substrate; LED chip, the LED chip is mounted on the substrate; A phosphor layer, the phosphor layer being disposed on a side of the LED chip away from the substrate; Wherein, the phosphor layer is made of yellow-green phosphor and red phosphor, and the thickness of the phosphor layer is greater than 70um and does not exceed 80um.
2. The LED packaging structure according to claim 1, characterized in that: A heat insulation layer is also provided between the LED chip and the phosphor layer.
3. The LED packaging structure according to claim 2, characterized in that: The heat insulating layer is made of a transparent glass sheet.
4. The LED packaging structure according to claim 3, characterized in that: The thickness of the transparent glass sheet is not less than 0.5 mm; or, a pattern layer is provided on the surface or inside of the transparent glass sheet.
5. The LED packaging structure according to claim 4, characterized in that: An adhesive layer is also provided between the transparent glass sheet and the LED chip; the thickness of the adhesive layer does not exceed 5 um.
6. The LED packaging structure according to claim 1, characterized in that: The LED chip is a blue light chip or a purple light chip.
7. The LED packaging structure according to claim 2, characterized in that: The LED packaging structure also includes a light shielding adhesive layer arranged on the substrate; the light shielding adhesive layer is arranged around the LED chip.
8. The LED packaging structure according to claim 7, characterized in that: The thickness of the light-shielding adhesive layer is greater than the maximum height of the LED chip relative to the substrate, and does not exceed the maximum height of the heat-insulating layer relative to the substrate.
9. An LED module, characterized in that: The LED module comprises the LED packaging structure as described in any one of claims 1-8.
10. A lighting device, characterized in that: The lighting device comprises the LED packaging structure as described in any one of claims 1 to 8 or the LED module as described in claim 9.