Anti-yellowing LED packaging device and packaging method
By setting vertical through-holes in the light conversion layer and filling them with a material with high gas permeability, the yellowing and blackening problems of fluorescent film products are solved, improving the optical consistency and reliability of LED packaging devices and extending their service life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-23
- Publication Date
- 2026-03-27
AI Technical Summary
Fluorescent film products are prone to yellowing or blackening during high-temperature or high-temperature and high-humidity aging tests, and existing technologies lack effective qualitative and quantitative detection methods, which affects the light efficiency and reliability of the devices.
Vertical vias are set in the light conversion layer and filled with a high gas permeability material to form an oxygen diffusion channel, which decomposes the dark small molecules generated during aging. Combined with the optimized design of the adhesive layer and high reflectivity layer, the interfacial bonding and optical consistency are improved.
It significantly suppressed yellowing and blackening phenomena in the interface area, reduced the risk of light decay of the device during long-term aging, extended the service life, and improved product yield and packaging reliability.
Smart Images
Figure CN121751847A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of LED packaging technology, specifically relating to an anti-yellowing LED packaging device and packaging method. Background Technology
[0002] Currently, as LED technology continues to develop towards higher power, miniaturization, and higher reliability, flip-chip structures have become the mainstream solution for high-power white LED packaging due to their excellent heat dissipation performance and high power density. In traditional phosphor coating processes, problems such as phosphor sedimentation and difficulty in controlling coating uniformity often lead to quality defects in white LEDs, such as inconsistent color temperature and reduced luminous efficacy.
[0003] To overcome the aforementioned limitations, phosphor film mounting technology has emerged. This technology involves pre-dispersing phosphor uniformly in silicone or polymer materials, forming a uniform film through a hot-pressing process, and then directly mounting it onto the surface of the LED chip, thereby significantly improving the optical consistency and packaging reliability of white LEDs. Currently, this technology has been maturely applied in packaging scenarios requiring high brightness, high reliability, and narrow emission angles, such as plant lighting and high-end backlighting. However, phosphor film-mounted flip-chip LEDs still face several technical bottlenecks in practical applications, restricting further improvements in their performance and reliability. These mainly include: 1. Insufficient interfacial adhesion, leading to delamination; 2. Limited thermal management efficiency, posing a risk of localized overheating; 3. Difficulty in process control, resulting in potential quality issues; and 4. Lack of effective quantitative evaluation methods for adhesion.
[0004] Currently, there is no reliable qualitative and quantitative testing method for assessing the bonding strength between chips and fluorescent films. In existing technologies, when using traditional push-blade tests to measure the bonding force between the chip and the film, the fluorescent film is soft and extremely thin (approximately 100 μm). This often leads to test failure due to insufficient push-blade descent precision: the push-blade easily touches the chip or partially damages the fluorescent film, making complete and accurate peel-off testing impossible, resulting in distorted bonding strength data. This problem directly hinders the quantitative evaluation of interface bonding quality and process optimization.
[0005] Phosphor films often exhibit yellowing or blackening during high-temperature or high-temperature-humidity aging tests, and this phenomenon originates from the silicone bonding layer between the phosphor film and the chip. Experiments show that the blackening of the material is reduced after illumination at room temperature, suggesting the formation of dark, volatile small molecules inside the package during the aging process. Although no lens peeling is observed externally, the formation and migration of these volatiles at the interface significantly reduces light extraction efficiency and threatens the long-term reliability of the device.
[0006] Therefore, a new technology is needed to solve the problem of yellowing and blackening that easily occurs in existing fluorescent film products. Summary of the Invention
[0007] To address the aforementioned problems in the prior art, this invention provides an anti-yellowing LED packaging device and packaging method, which can significantly suppress yellowing and blackening phenomena in the interface area, reduce the risk of light decay during long-term aging, and extend the service life.
[0008] The present invention adopts the following technical solution: An anti-yellowing LED packaging device includes a substrate, a light-emitting diode (LED), an adhesive layer, a light conversion layer, a high-reflectivity layer, and a lens layer. The LED is fixed on the substrate. The light conversion layer is attached above the LED through the adhesive layer. The high-reflectivity layer surrounds the LED and the sides of the light conversion layer. The lens layer covers the light conversion layer and the high-reflectivity layer. At least one through-hole is vertically provided in the light conversion layer, and the position of each through-hole corresponds to the electrode area of the LED. As a further improvement to the technical solution of the present invention, the light conversion layer is horizontally arranged and located directly above the light-emitting diode, and the cross-sectional dimension of the light conversion layer is larger than the cross-sectional dimension of the light-emitting diode.
[0009] As a further improvement to the technical solution of the present invention, the four periphery of the light conversion layer protrudes from the side of the light-emitting diode.
[0010] As a further improvement to the technical solution of the present invention, the adhesive layer is coated on the upper surface and part of the sidewall of the light-emitting diode.
[0011] As a further improvement to the technical solution of the present invention, the thickness of the adhesive layer is 5μm~30μm.
[0012] As a further improvement to the technical solution of the present invention, the high reflectivity layer is filled in the sidewall region surrounding the light-emitting diode and the light conversion layer; The bottom of the high-reflectivity layer covers a portion of the upper surface of the substrate outside the light-emitting diode.
[0013] As a further improvement to the technical solution of the present invention, the upper surface of the high reflectivity layer is flush with the upper surface of the light conversion layer.
[0014] As a further improvement to the technical solution of the present invention, the diameter of each through hole is less than 5 mil.
[0015] As a further improvement to the technical solution of the present invention, each of the through holes is provided with a filling material, and the gas permeability of the filling material is higher than that of the light conversion layer.
[0016] An anti-yellowing LED packaging device and packaging method, used to manufacture the LED packaging device as described above, includes the following steps: S1. The light-emitting diode is disposed on the substrate in a flip-chip manner, and electrical connection and fixation are achieved by solder or conductive adhesive; S2. The adhesive layer is applied to the light-emitting surface and part of the sidewall of the light-emitting diode; S3. The light conversion layer is placed on the adhesive layer. The light conversion layer has through-hole structures that penetrate the light conversion layer. Each through-hole corresponds to the electrode area of the light-emitting diode. The through-holes are formed in the light conversion layer by pre-processing with precision stamping or laser etching. Alternatively, a mask with openings matching the electrode pattern is covered on the surface of the bonded light conversion layer, and the material is selectively removed using a chemical etching solution to form the through-hole structure. S4. The high reflectivity layer is filled in the surrounding sidewall area of the light-emitting diode and the light conversion layer. The high reflectivity layer material is silicone or epoxy resin mixed with white scattering particles. The silicone or epoxy resin mixed with white scattering particles is dispensed, leveled, and then baked and cured under certain conditions to form an enclosing structure, thereby forming the high reflectivity layer. S5. A lens layer is disposed above the light conversion layer and the high reflectivity layer. The lens layer is formed by molding or bonding. After the lens layer is formed, the overall encapsulation is completed.
[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: This design incorporates a via structure in the light conversion layer. Based on the mechanism by which oxygen can participate in the decomposition of dark-colored carbonaceous substances generated during aging—a mechanism known as "photofading"—the vertical vias in the light conversion layer constitute effective oxygen diffusion channels. This structure facilitates the penetration of oxygen from the external environment to the interface between the LED and the light conversion layer, promptly decomposing the dark-colored small molecules produced by thermal aging. This significantly suppresses yellowing and blackening at the interface, reduces the risk of light decay during long-term aging, and extends the device's lifespan. Attached Figure Description
[0018] The technology of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments: Figure 1 This is a cross-sectional view of the overall structure of the present invention; Figure 2 This is a cross-sectional view of the overall structure when filler material is placed inside the through hole; Figure 3 This is a partial top view of the structure of the present invention.
[0019] Figure label: 1-Substrate; 2-Light Emitting Diode; 3-Adhesive layer; 4-Light conversion layer; 41-Through hole; 42-Fill material; 5-High reflectivity layer; 6-Lens layer. Detailed Implementation
[0020] The following will provide a clear and complete description of the concept, specific structure, and technical effects of the present invention in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, solution, and effects of the present invention. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The same reference numerals used throughout the accompanying drawings indicate the same or similar parts.
[0021] It should be noted that, unless otherwise specified, when a feature is referred to as "fixed" or "connected" to another feature, it can be directly fixed or connected to the other feature, or indirectly fixed or connected to the other feature. Furthermore, the descriptions of "up," "down," "left," and "right" used in this invention are only relative to the relative positional relationships of the various components of the invention in the accompanying drawings.
[0022] Reference Figures 1 to 3 An anti-yellowing LED packaging device includes a substrate 1, a light-emitting diode 2, an adhesive layer 3, a light conversion layer 4, a high-reflectivity layer 5, and a lens layer 6. The light-emitting diode 2 is fixed on the substrate 1. The light conversion layer 4 is attached to the light-emitting diode 2 via the adhesive layer 3. The high-reflectivity layer 5 surrounds the sides of the light-emitting diode 2 and the light conversion layer 4. The lens layer 6 covers the light conversion layer 4 and the high-reflectivity layer 5. At least one through-hole 41 is vertically provided in the light conversion layer 4. The position of each through-hole 41 corresponds to the electrode area of the light-emitting diode 2. Each through-hole 41 can correspond one-to-one with the position of the electrode of each light-emitting diode 2 on the chip, or at least one through-hole 41 can be provided at the position of the electrode of each light-emitting diode 2, depending on the actual situation. The LED chip is fixed on the substrate 1, that is, the light-emitting diode 2 of the chip is also fixed on the substrate 1. Based on the mechanism by which oxygen can participate in the decomposition of dark carbonaceous substances generated during the aging process, namely the "photo-induced fading" mechanism, the vertical vias 41 of the light conversion layer 4 in this design constitute an effective oxygen diffusion channel. This structure facilitates the penetration of oxygen from the external environment to the interface between the light-emitting diode 2 and the light conversion layer 4 of the chip, promptly decomposing the dark small molecules generated by thermal aging, thereby significantly suppressing yellowing and blackening phenomena in the interface region, reducing the risk of light decay during long-term aging of the device, and extending its service life.
[0023] The via 41 structure in the light conversion layer 4 of this solution allows operators to directly and quickly determine whether the lower area of the via 41 is fully filled by the adhesive layer 3 material by visually observing during dispensing or bonding. This provides a straightforward and quick way to judge whether the bonding between the light conversion layer 4 and the light-emitting diode 2 or the chip is complete and sufficient. This effectively solves the quality problems of poor bonding or voids caused by the inability to observe the interface in traditional processes, improves product yield and consistency, and provides a simple and non-destructive testing method for packaging process quality. Specifically, the light conversion layer 4 is horizontally arranged and located directly above the light-emitting diode 2. The cross-sectional dimension of the light conversion layer 4 is larger than that of the light-emitting diode 2. The four peripheral edges of the light conversion layer 4 protrude from the side of the light-emitting diode 2 so as to fully cover the light-emitting interface of the light-emitting diode 2.
[0024] Specifically, the adhesive layer 3 is coated on the light-emitting surface and part of the sidewall of the light-emitting diode 2. The thickness of the adhesive layer 3 is 5μm~30μm. The material of the adhesive layer 3 can be transparent silicone or high refractive index organic glue to reduce the light emission loss of the light-emitting diode 2.
[0025] Specifically, the high-reflectivity layer 5 fills the sidewall region surrounding the light-emitting diode 2 and the light conversion layer 4. The bottom of the high-reflectivity layer 5 covers a portion of the upper surface of the substrate 1 outside the light-emitting diode 2.
[0026] Specifically, the upper surface of the high reflectivity layer 5 is flush with the upper surface of the light conversion layer 4.
[0027] Specifically, the diameter of each through-hole 41 is smaller than the N electrode of the light-emitting diode 2, and the diameter of the through-hole 41 is typically less than 5 mil. Figure 1 As shown, the highest point of the upper surface of the adhesive layer 3 is not lower than the lowest point of the through-hole 41, allowing the upper part of the adhesive layer 3 to extend into the through-hole 41. Furthermore, the lower surface of the adhesive layer 3 is lower than the lowest point of the through-hole 41, ensuring that the through-hole 41 remains vertically connected while allowing effective escape of interfacial gas. This solution improves the anti-aging performance and structural reliability of the device by optimizing the design and layout of the through-hole 41 on the light conversion layer 4. In this solution, the light conversion layer 4 has through-holes 41 in the electrode region corresponding to the light-emitting diode 2 on the chip. There is at least one through-hole 41, which is a vertically connected structure and can be formed using any of the following methods: die stamping, laser processing, or mask etching.
[0028] Specifically, each of the through holes 41 is provided with a filling material 42. The through holes 41 of the light conversion layer 4 can be filled with a filling material 42 with high gas permeability, that is, a gas permeability much higher than that of the lens layer 6 material, to replace the through holes 41. The gas permeability of the filling material 42 is higher than that of the light conversion layer 4. The filling material 42 can be provided or not provided according to the actual situation. The appearance and shape of the filling material 42 can be set according to the actual situation. The filling material 42 can be transparent or opaque.
[0029] A packaging method for an anti-yellowing LED packaged device, used to manufacture the aforementioned anti-yellowing LED packaged device, includes the following steps: S1. The light-emitting diode 2 is disposed on the substrate 1 in a flip-chip manner, that is, a flip-chip structure is fabricated, for example, the chip and its light-emitting diode 2 are disposed on the metal plating layer of the ceramic substrate 1 in a flip-chip manner, and electrical connection and fixation are achieved by solder or conductive adhesive.
[0030] S2. The adhesive layer 3 is coated on the upper surface and part of the sidewall of the light-emitting diode 2. The material can be transparent silicone or high refractive index organic adhesive, and the thickness is controlled in the range of 5μm~30μm.
[0031] S3. The light conversion layer 4 is disposed on the adhesive layer 3, and a through-hole 41 structure is provided inside the light conversion layer 4, the position of the through-hole 41 corresponding to the electrode area of the light-emitting diode 2. The through-hole 41 can be formed in the light conversion layer 4 by pre-processing it with precision stamping or laser etching; or by covering the surface of the bonded light conversion layer 4 with a mask having openings matching the electrode pattern, and selectively removing the material with a chemical etching solution to form the through-hole 41 structure.
[0032] When a filling material 42 needs to be placed inside the through-hole 41, after the opening process of the through-hole 41 is completed, it is attached to the adhesive layer 3. Subsequently, a transparent encapsulation material with high oxygen permeability, such as porous silica gel, a specific organosilicon compound, or a polymer with a microporous structure, can be injected into each of the through-holes 41 through precision dispensing or vacuum filling processes to completely fill the space of the through-hole 41. The oxygen permeability of the filling material 42 should be significantly higher than that of the substrate material of the light conversion layer 4 to ensure that the gaseous byproducts generated by the interface reaction can effectively diffuse outward through the through-hole 41, while oxygen in the environment can also smoothly enter the through-hole 41 to maintain its anti-yellowing function. The setting of the filling material 42 inside the through-hole 41, while retaining the gas channel function, further enhances the integrity of the interface structure and avoids the mechanical strength reduction or interface contamination problems that may be caused by the presence of the through-hole 41. (Refer to...) Figure 2As shown, the filling material 42 is located in the upper part of the through hole 41, and the bottom of the through hole 41 is a partial adhesive layer 3 structure. The filling material 42 is in close contact with the adhesive layer 3 in the through hole 41, and the height of the filling material 42 in the through hole 41 is much greater than the height of the adhesive layer 3.
[0033] S4. The high reflectivity layer 5 is filled in the surrounding sidewall area of the light-emitting diode 2 and the light conversion layer 4. The material of the high reflectivity layer 5 is silicone or epoxy resin mixed with white scattering particles. The above materials are applied and leveled, and then baked and cured under certain conditions to form an enclosing structure, that is, to form the high reflectivity layer 5 structure, so as to improve the light extraction efficiency.
[0034] S5. A lens layer 6 is provided above the light conversion layer 4 and the high reflectivity layer 5. The lens layer 6 can be a planar, convex or free-form surface structure. The lens layer 6 is formed by molding or bonding to control the light distribution. After the lens layer 6 is formed, the overall encapsulation is completed, forming an overall encapsulation structure with a flat surface and dense structure.
[0035] Other aspects of the anti-yellowing LED packaging device and packaging method described in this invention can be found in the prior art and will not be repeated here.
[0036] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.
Claims
1. An anti-yellowing LED package device, characterized by: The application relates to a light-emitting diode package, which comprises a substrate, a light-emitting diode fixed on the substrate, an adhesive layer, a light conversion layer, a high-reflection layer and a lens layer, wherein the light conversion layer is attached above the light-emitting diode through the adhesive layer, the high-reflection layer surrounds the light-emitting diode and the light conversion layer, and the lens layer covers the light conversion layer and the high-reflection layer; at least one through hole is vertically arranged in the light conversion layer, and the position of each through hole corresponds to an electrode area of the light-emitting diode.
2. The anti-yellowing LED packaging device of claim 1, wherein: The light conversion layer is horizontally arranged and located directly above the light-emitting diode, and the cross-sectional size of the light conversion layer is larger than that of the light-emitting diode.
3. The anti-yellowing LED packaging device of claim 2, wherein: The four periphery edges of the light conversion layer protrude from the side surface of the light-emitting diode.
4. The anti-yellowing LED packaging device of claim 3, wherein: The adhesive layer is coated on the upper surface and part of the side wall of the light-emitting diode.
5. The anti-yellowing LED encapsulant device of claim 4, wherein: The thickness of the adhesive layer is 5-30 microns.
6. The anti-yellowing LED encapsulant device of claim 5, wherein: The high-reflection layer is filled in the side wall area around the light-emitting diode and the light conversion layer. The bottom of the high-reflection layer covers part of the upper surface of the substrate outside the light-emitting diode.
7. The anti-yellowing LED packaging device of claim 1, wherein: The upper end surface of the high-reflection layer is flush with the upper end surface of the light conversion layer.
8. The anti-yellowing LED packaging device of claim 5, wherein: The diameter of each through hole is less than 5 mil.
9. The anti-yellowing LED packaging device of claim 8, wherein: A filling material is arranged in each through hole, and the gas permeability of the filling material is higher than that of the light conversion layer.
10. A yellowing-resistant LED packaging device and a packaging method for manufacturing the yellowing-resistant LED packaging device according to any one of claims 1 to 9, characterized by: The application further discloses a preparation method of the light-emitting diode package. S1. The light-emitting diode is arranged on the substrate in an inverted manner, and electrical connection and fixation are realized through solder or conductive glue; S2. The adhesive layer is coated on the upper surface and part of the side wall of the light-emitting diode; S3. The light conversion layer is arranged above the adhesive layer, the light conversion layer is internally provided with a through hole structure penetrating through the light conversion layer, and the position of each through hole corresponds to the electrode area of the light-emitting diode; wherein the through hole is formed by pre-adopting a precise stamping or laser etching process in the light conversion layer; or a mask plate with openings matched with the electrode pattern is arranged on the surface of the attached light conversion layer, and a chemical etching liquid is used to selectively remove materials to form the through hole structure; S4. The high-reflection layer is filled in the side wall area around the light-emitting diode and the light conversion layer, the high-reflection layer material is silica gel or epoxy resin mixed with white scattering particles, the silica gel or epoxy resin material mixed with white scattering particles is glued, leveled and then baked and solidified under certain conditions to form a surrounding structure, thereby forming the high-reflection layer; S5. The lens layer is arranged above the light conversion layer and the high-reflection layer, and the lens layer is formed through molding or attachment, and the overall packaging is completed after the lens layer is formed.