Full-spectrum high-color-rendering LED lamp bead

Abstract

The application relates to the technical field of semiconductor lighting, in particular to a full-spectrum high-color-rendering LED lamp bead. The lamp bead comprises an LED support, a blue light excitation chip, a red light enhancement chip, a multi-component fluorescent material system, a silicone encapsulation lens and a heat management structure. The blue light excitation chip and the red light enhancement chip are die-bonded on the LED support and form electrical connections with the positive and negative electrode pads respectively; the multi-component fluorescent material system is formed on the chip surface by adopting a partition coating process; the heat management structure comprises a high-thermal-conductivity ceramic substrate and a silver-plated copper alloy support frame. The application realizes full-spectrum coverage through the blue light excitation chip combined with the multi-component fluorescent material system, and simultaneously configures the red light enhancement chip to supplement the red light band energy, adopts an optimized partition coating process and a multi-layer fluorescent structure design, effectively controls the proportion of blue light overflow, and improves the light conversion efficiency. The lamp bead can significantly improve the general color rendering index Ra and the special color rendering index R9, realizes low blue light hazard, high luminous efficiency and good thermal stability.

Description

Technical Field

[0001] This application belongs to the field of semiconductor lighting technology, specifically relating to a full-spectrum LED lamp bead with high color rendering. Background Technology

[0002] Light-emitting diodes (LEDs), as a new generation of solid-state lighting sources, have been widely used in many fields such as general lighting, display backlighting, plant lighting, and medical lighting due to their significant advantages such as high luminous efficiency, long lifespan, and environmental friendliness. With continuous breakthroughs in semiconductor material technology and increasingly mature packaging processes, the luminous efficiency of LED devices is constantly improving, while costs are continuously decreasing, gradually replacing traditional incandescent and fluorescent lamps as the mainstream choice in the lighting market. The core indicators for measuring the quality of LED lighting include not only luminous efficiency and lifespan, but also the ability of the light source to reproduce the true colors of objects, i.e., color rendering performance. To meet people's pursuit of high-quality lighting environments, full-spectrum LED technology has emerged, aiming to achieve a high degree of consistency between the spectral distribution of the light source and natural sunlight, thereby providing more favorable lighting conditions for human visual health and physiological rhythms.

[0003] Among them, full-spectrum high color rendering LED chips, as key components for achieving high-quality lighting effects, rely on the precise tuning of the spectral conversion characteristics of various fluorescent materials to enable LED light sources to cover the entire visible light spectrum (380nm to 780nm) and achieve high general color rendering index (Ra value) and special color rendering index (especially R9 red light color rendering index) at the target color temperature. By simulating the spectral power distribution of natural light, full-spectrum LED chips can effectively reproduce the true colors of illuminated objects, providing a visual experience close to natural sunlight for indoor lighting, professional color recognition, art displays, and other fields. Therefore, they have become a key development direction for the high-end lighting market and professional lighting applications.

[0004] However, existing full-spectrum high color rendering LED chips still face many technical bottlenecks in practical applications. Because the human eye has low sensitivity to the red light region, simply increasing the proportion of red phosphor to improve the color rendering index leads to a significant decrease in the luminous efficacy of the LED light source, creating an irreconcilable contradiction between luminous efficiency and color rendering performance. Simultaneously, red phosphor materials are prone to light decay and color drift under prolonged high-temperature operating conditions, severely affecting the stability and color consistency of LED chips. Furthermore, while using violet chips to excite multicolor phosphors can improve spectral continuity to some extent, its luminous efficacy remains low, and the high cost and immature reliability of violet chips further restrict the large-scale commercial application of this technology. Although blue light excitation is currently the mainstream choice in the market, traditional blue-excited full-spectrum LEDs have relatively insufficient energy in the red light region, with a high proportion of blue light, and their consistency with the natural spectrum still falls short, making it difficult to simultaneously meet the comprehensive performance requirements of high color rendering index, low blue light hazard, and high luminous efficacy. The aforementioned technical defects severely restrict the promotion and application of full-spectrum high color rendering LED chips in the high-end lighting market, and there is an urgent need to seek technological breakthroughs in material systems and structural design. Summary of the Invention

[0005] The purpose of this invention is to provide a full-spectrum high color rendering LED bead, which can effectively solve the technical problems of insufficient energy in the red light region of the spectrum, high proportion of blue light, and difficulty in balancing luminous efficiency and color rendering performance in existing full-spectrum high color rendering LED beads in the background art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A full-spectrum, high color rendering LED chip includes an LED bracket, a blue excitation chip, a red enhancement chip, a multi-component fluorescent material system, a silicone resin encapsulation lens, and a thermal management structure. The LED bracket has positive and negative electrode pads. The blue excitation chip and the red enhancement chip are die-bonded onto the LED bracket and electrically connected to the positive and negative electrode pads, respectively. The multi-component fluorescent material system is formed on the surfaces of the blue excitation chip and the red enhancement chip using a partitioned coating process. The silicone resin encapsulation lens is disposed above the LED bracket and covers the multi-component fluorescent material system. The thermal management structure includes a high thermal conductivity ceramic substrate and a silver-plated copper alloy support frame for conducting heat generated by the chip to the outside.

[0007] A full-spectrum, high color rendering LED light bead, the manufacturing method of which includes the following specific steps: Step 1: Design the LED bracket frame structure: Select silver-plated copper alloy as the main material of the bracket, control the thickness of the silver plating layer within a preset thickness range, and adapt the bracket frame thickness to the preset thickness range. The bracket frame is provided with positive electrode pads and negative electrode pads, and the thickness of the silver plating layer in the positive electrode pad and negative electrode pad areas is increased to a preset increase range. The silver plating treatment of the LED bracket increases the surface reflectivity of the bracket to a preset reflectivity, while ensuring that the bracket has a thermal conductivity not lower than a preset thermal conductivity threshold. Step 2: Design parameters for the blue light excitation chip: The blue light excitation chip uses an InGaN material system, sets the main wavelength range to a preset blue light wavelength range, controls the half-width at half-maximum (WWHM) within a preset WWHM range, adapts the chip size to a preset size range, sets the driving current to a preset driving current value, sets the driving voltage to a preset voltage range, and achieves a preset power output range; the blue light excitation chip employs an optimized quantum well structure design to achieve high peak brightness and luminous efficacy, and the emission angle is within a preset angle range; Step 3: Design parameters for the red light enhancement chip: The red light enhancement chip uses an AlGaInP material system, sets the main wavelength range to a preset red light wavelength range, controls the half-width at half-maximum (WWHM) within a preset WWHM range, keeps the chip size consistent with the blue light excitation chip to optimize the packaging layout, sets the driving current to a preset driving current value, sets the driving voltage to a preset voltage range, and sets the output power to a preset power range; the red light enhancement chip adopts a high-efficiency structure design to supplement the energy distribution of the LED light source in the red light band. Step 4: Design of a multi-component fluorescent material system: The multi-component fluorescent material system includes a nitride red phosphor, an aluminate green phosphor, and a silicate green phosphor; the peak wavelength range of the nitride red phosphor is within a preset red phosphor wavelength range, and the half-width is the preset red phosphor width, exhibiting excellent thermal stability; the peak wavelength range of the aluminate green phosphor is within a preset green phosphor wavelength range one, and the half-width is the preset green phosphor width one; the peak wavelength range of the silicate green phosphor is within a preset green phosphor wavelength range two, and the half-width is the preset green phosphor width two, possessing narrowband emission characteristics to extend the spectral coverage of the green light band; Step 5: Design the partitioned coating process: The partitioned coating process coats the fluorescent material in three layers onto the surfaces of the blue light excitation chip and the red light enhancement chip; the bottom layer is coated with a mixture of the nitride red phosphor and the aluminate green phosphor, with the mass ratio of red phosphor to green phosphor within a preset powder ratio range, and the coating thickness is controlled within a preset bottom layer thickness range; the middle layer is coated with a mixture of the aluminate green phosphor and the silicate green phosphor, with a thickness within a preset middle layer thickness range; the top layer is coated with a single layer of the aluminate green phosphor, with a thickness within a preset top layer thickness range; the total thickness of the three fluorescent layers is controlled within a preset total thickness range; Step 6: Design the encapsulation structure and optical lens: The encapsulation structure uses high-transmittance silicone resin material, with the refractive index controlled within a preset refractive index range, the transmittance reaching a preset transmittance threshold, and the Shore hardness within a preset hardness range; the optical lens uses hemispherical methyl silicone resin material, with a radius of curvature within a preset curvature range, a height within a preset height range, and a preset air gap between the lens and the LED bracket to reduce the absorption loss of short-wavelength blue light by the encapsulation material.

[0008] Preferably, in step 2, the blue light excitation chip adopts a vertical structure design with an InGaN material system and a sapphire substrate. The thickness of the sapphire substrate is controlled within a preset substrate thickness range. A current spreading layer is provided on the upper surface of the chip. The current spreading layer uses an indium tin oxide transparent conductive film to improve the uniformity of current distribution and light extraction efficiency. The emission wavelength of the blue light excitation chip is a preset blue light wavelength range corresponding to the center position of the blue light band, which can effectively excite the fluorescent materials of each component to generate visible light of the target wavelength. The quantum wells of the blue light excitation chip adopt an InGaN / GaN multi-quantum-well structure, the barrier layer uses GaN or AlGaN material, and the number of quantum wells is set to a preset number of wells to optimize the carrier recombination efficiency.

[0009] Preferably, in step 3, the red light enhancement chip adopts a GaAs substrate structure design based on the AlGaInP material system. The thickness of the GaAs substrate is controlled within a preset substrate thickness range. The chip adopts a DBR reflective layer structure to improve light extraction efficiency. The DBR reflective layer is disposed between the active layer and the GaAs substrate. The emission wavelength of the red light enhancement chip is preset to be within the red light wavelength range of the human eye, which can effectively supplement the energy distribution of the LED light source in the red light band. The relative positions of the red light enhancement chip and the blue light excitation chip on the LED bracket are optimized according to the optical design and can be arranged side by side or coaxially.

[0010] Preferably, in step 4, the nitride red phosphor adopts a CaAlSiN3 crystal structure activated by Eu2+ ions, and its quantum efficiency reaches a preset quantum efficiency threshold one at room temperature and remains above a preset quantum efficiency threshold two at high temperature; the aluminate green phosphor adopts a Lu3Al5O12 crystal structure activated by Ce3+ ions, and its quantum efficiency exceeds a preset quantum efficiency threshold three at room temperature; the silicate green phosphor adopts a Beta-SiAlON crystal structure activated by Eu2+, and its quantum efficiency exceeds a preset quantum efficiency threshold four at room temperature; the particle size distribution D50 of the three phosphors is controlled within preset particle size range one, preset particle size range two, and preset particle size range three, respectively, to optimize coating processability and light conversion efficiency.

[0011] Preferably, in step 4, the mass ratio of the three phosphors is as follows: the mass ratio of nitride red phosphor to aluminate green phosphor is within a preset powder ratio range one, and the mass ratio of silicate green phosphor to nitride red phosphor is within a preset powder ratio range two. This ratio ensures that the LED light source covers the entire visible light spectrum at the target color temperature, with the general color rendering index Ra exceeding a preset color rendering index threshold one, and the special color rendering index R9 exceeding a preset color rendering index threshold two. After the three phosphors are uniformly mixed, they are dispersed in a silicone resin carrier, and the solid content is controlled within a preset solid content range to ensure uniform coating of the fluorescent layer.

[0012] Preferably, in step 5, the bottom layer coating is applied to the area around the chip, covering an area that reaches a preset coverage range of the total chip area, ensuring that the blue light excitation light can be fully converted; the width of the middle layer coating is a preset difference from the width of the bottom layer coating, forming an extended fluorescent coverage to improve the light conversion efficiency; the partitioned coating structure allows the blue light excitation light to be converted gradually along the propagation direction, extending the optical path and improving the conversion efficiency, while effectively reducing the proportion of blue light spillover.

[0013] Preferably, in step 6, the silicone resin encapsulated lens is made of methyl silicone resin, with its refractive index controlled within a preset refractive index range, its light transmittance reaching a preset light transmittance threshold, and its ability to withstand a preset operating temperature range. The lens adopts a hemispherical structure design, with its radius of curvature within a preset curvature range, its height within a preset height range, its center thickness within a preset center thickness range, its bottom diameter within a preset bottom diameter range, and its surface roughness Ra controlled within a preset roughness range to reduce light scattering loss.

[0014] Preferably, in step 6, the positioning of the lens and the LED bracket is ensured by a precision mold to ensure that the coaxiality deviation is less than a preset coaxiality threshold, thus ensuring that the optical axis of the lens is aligned with the light-emitting center of the LED chip; the hemispherical lens structure can collimate and focus the light emitted by the chip, significantly improving the directionality of light output and thus improving the luminous efficiency of the lamp; the low refractive index environment of the air gap effectively reduces the absorption loss of short-wavelength blue light by the encapsulation material.

[0015] Preferably, the high thermal conductivity ceramic substrate in the thermal management structure is made of aluminum nitride, with a thermal conductivity within a preset range and a thermal resistance within a preset range; the silver plating layer of the silver-plated copper alloy bracket has a preset thickness range, a preset total thickness range, and a thermal conductivity exceeding a preset thermal conductivity threshold; the die bonding area of ​​the chip uses high thermal conductivity silicone grease or solder as a thermal interface, with a thermal resistance within a preset die bonding thermal resistance range, ensuring that the heat from the PN junction is efficiently conducted to the ceramic substrate and transferred to the external heat sink via the copper frame.

[0016] Preferably, the positive and negative electrode pads of the LED bracket are made of silver-plated copper alloy, with the silver plating layer thickness within a preset range and the surface roughness Ra of the pads controlled within a preset range to ensure good welding performance and light reflection performance. The blue light excitation chip is die-bonded to the positive electrode pad of the LED bracket via gold-tin eutectic bonding, with the die-bonding layer thickness controlled within a preset range and the die-bonding thermal resistance lower than a preset die-bonding thermal resistance threshold. The red light enhancement chip is die-bonded to the negative electrode pad of the LED bracket, and the die-bonding process parameters are consistent with those of the blue light excitation chip.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. Superior spectral quality: Full-spectrum coverage is achieved through a blue light excitation chip combined with a multi-component fluorescent material system. At the same time, a red light enhancement chip is configured to supplement the red light band energy, so that the spectral distribution matches the natural sunlight to a preset matching threshold, effectively restoring the true color of the illuminated object. The general color rendering index Ra exceeds the preset color rendering index threshold one, and the special color rendering index R9 exceeds the preset color rendering index threshold two and R12 exceeds the preset color rendering index threshold three, which has significant advantages in high-end home lighting, professional color recognition, art display and other fields.

[0018] 2. High luminous efficiency: Optimized multi-component phosphor ratio and zoned coating process achieve high light conversion efficiency. The blue light excitation chip achieves the preset luminous efficiency range under preset driving conditions. The introduction of the red light enhancement chip effectively supplements the red light energy without significantly losing the overall luminous efficiency. Silicone resin encapsulation material and optimized optical lens design further reduce light loss and improve light extraction efficiency.

[0019] 3. Low blue light hazard: Through zoned coating process and multi-layer fluorescent structure design, the proportion of blue light leakage is effectively controlled, and the proportion of blue light is controlled within the preset blue light proportion range, which significantly reduces the adverse effects of blue light on human visual health and physiological rhythm, and provides a safer and more comfortable lighting environment.

[0020] 4. High stability and long lifespan: The high thermal conductivity ceramic substrate, combined with the optimized thermal management structure, keeps the operating temperature within the preset operating temperature threshold, effectively reducing the risk of light decay and color drift of the fluorescent material; the high-temperature resistant nitride red powder and the stable multi-component fluorescent system ensure color consistency; the lifespan of the LED exceeds the preset lifespan threshold, and the color coordinate drift is controlled below the preset drift threshold. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall technical solution architecture of the full-spectrum high color rendering LED lamp beads according to the embodiments of this application; Figure 2This is a schematic diagram illustrating the core principle framework of the collaborative operation of the blue light excitation chip and the red light enhancement chip in a full-spectrum high color rendering LED according to an embodiment of this application. Figure 3 This is a logical flow diagram of the partition coating process for a multi-component fluorescent material system in a full-spectrum high color rendering LED according to an embodiment of this application; Figure 4 This is a schematic diagram comparing the color rendering performance of full-spectrum high color rendering LED beads according to embodiments of this application with that of the prior art. Detailed Implementation Example

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0023] The full-spectrum high color rendering LED chip disclosed in this invention achieves full-spectrum lighting effects through a systematic design approach. The design of this LED chip encompasses six core aspects: LED bracket frame structure design, blue light excitation chip parameter design, red light enhancement chip parameter design, multi-component fluorescent material system design, zoned coating process design, and packaging structure and optical lens design. These aspects are closely coupled and collectively determine the spectral quality, luminous efficiency, thermal stability, and lifespan of the final product.

[0024] In the LED bracket frame structure design stage, i.e., step 1, the LED bracket serves as the mechanical support foundation and electrical connection carrier for the entire LED chip. Its material selection and structural design directly affect the optical performance, thermal performance, and reliability of the package. The main material of the LED bracket is a silver-plated copper alloy. The copper alloy substrate provides excellent mechanical strength and thermal conductivity, while the silver plating offers the dual advantages of high reflectivity and good solderability. The silver plating thickness is controlled within the range of 2μm to 5μm. This thickness range ensures sufficient density and adhesion strength of the plating while avoiding increased cost and brittleness due to excessive plating thickness. The bracket frame thickness is set between 0.8mm and 1.2mm. This thickness range ensures sufficient structural rigidity to support the weight of the chip and lens while maintaining low thermal resistance to promote effective heat conduction.

[0025] The LED bracket surface features two electrical connection areas: a positive pad and a negative pad. The silver plating thickness in these areas is increased to 4μm to 8μm, approximately 1 to 2 times thicker than the main silver plating layer. This thickened design significantly improves the reflectivity of the pad areas to over 95%, while ensuring a highly reliable electrical connection between the pads and bonding wires. The overall silver plating of the LED bracket increases the surface reflectivity to over 94%, effectively reducing light loss due to absorption by the bracket from the side of the chip and improving light extraction efficiency. Simultaneously, the thermal conductivity of the silver-plated copper alloy material is maintained within the range of 380W / (m·K) to 420W / (m·K), ensuring the bracket has a thermal conductivity threshold of no less than 380W / (m·K), providing an efficient conduction channel for the heat generated by the chip.

[0026] In the blue light excitation chip parameter design stage, i.e., step 2, the blue light excitation chip, as the excitation source of the full-spectrum light source, directly determines the excitation efficiency of the fluorescent material system and the blue light component of the final spectrum. The blue light excitation chip uses the InGaN material system, which features high quantum efficiency, high light output stability, and good antistatic properties, enabling high power output in the 400nm to 470nm blue light band. The dominant wavelength range is set to 440nm to 460nm, corresponding to the center of the blue light band, effectively exciting nitride red phosphors, aluminate green phosphors, and silicate green phosphors to produce visible light of the target wavelength, while avoiding the negative impact of the violet band on fluorescence conversion efficiency. The half-width at half-maximum (WWHM) of the blue light excitation chip is controlled within the range of 15nm to 20nm. A narrower WWHM ensures high monochromaticity of the blue excitation light, facilitating precise control of the spectral composition of the fluorescence conversion process.

[0027] The blue light excitation chip employs an optimized quantum well structure design to achieve high peak brightness and luminous efficiency. The quantum wells utilize an InGaN / GaN multi-quantum-well structure, forming an active light-emitting region with high injected carrier recombination efficiency by alternately growing InGaN well layers between GaN barrier layers. The barrier layers are made of GaN or AlGaN materials; the introduction of AlGaN improves the lattice mismatch between the barrier and well layers, enhancing the controllability of the quantum confined Stark effect (QCSE). The number of quantum wells is set to 5 to 10, a range that ensures high internal quantum efficiency while avoiding the problem of uneven carrier distribution caused by an excessive number of wells. The blue light excitation chip has a emission angle of 120° to 140°. This wide emission angle ensures that the blue excitation light can fully cover the phosphor layer, improving the uniformity of light conversion efficiency.

[0028] The blue light excitation chip employs a vertical structure design on a sapphire substrate based on the InGaN material system. The thickness of the sapphire substrate is controlled within the range of 80μm to 120μm, a thickness range that balances the dual requirements of substrate mechanical strength and light extraction efficiency. A current spreading layer is set on the upper surface of the chip, which is made of indium tin oxide (ITO) transparent conductive film. The ITO film thickness is controlled within the range of 200nm to 400nm, and the sheet resistance is controlled within the range of 10Ω to 30Ω. The ITO transparent conductive film has a transmittance of over 85% in the blue light band, while also possessing excellent conductivity, enabling the injected current to be evenly spread throughout the entire light-emitting area of ​​the chip, avoiding localized overheating and luminous efficiency degradation caused by current concentration. The application of the ITO film also improves the light extraction efficiency of the blue light excitation chip and reduces total internal reflection losses within the chip.

[0029] In terms of driving parameter design, the blue light excitation chip's size is adapted to range from 0.5mm×0.5mm to 1.0mm×1.0mm. This size range ensures sufficient light output power while facilitating die bonding and phosphor coating operations. The driving current is set from 350mA to 500mA, the driving voltage from 2.8V to 3.4V, and the output light power reaches from 500mW to 1000mW. Under the standard driving current of 350mA, the luminous efficacy of the blue light excitation chip can reach 45lm / W to 55lm / W, and the peak brightness reaches 2000mcd to 4000mcd. This driving parameter design ensures that the blue light excitation chip maintains good thermal stability while operating efficiently.

[0030] In the red light enhancement chip parameter design stage, i.e., step 3, the introduction of the red light enhancement chip aims to supplement the energy distribution of the LED light source in the red light band, solving the technical problem of insufficient energy in the red light region of traditional full-spectrum LED chips. The red light enhancement chip uses the AlGaInP material system, which has the highest luminous efficiency and best color saturation in the 620nm to 660nm red light band. The dominant wavelength range is set to 620nm to 640nm, which is located in the center of the human eye's red light sensitivity area (approximately 620nm to 630nm), effectively enhancing the visual response weight of the red light band. The half-width of the red light enhancement chip is controlled within the range of 15nm to 20nm. A narrower half-width ensures high color purity of the red light, avoiding a decrease in the color rendering index caused by an overly broad red light component.

[0031] The red light enhancement chip employs a GaAs substrate structure based on the AlGaInP material system. The GaAs substrate thickness is controlled within the range of 100μm to 150μm, ensuring sufficient mechanical strength and thermal conductivity to support the epitaxial layer structure. The chip utilizes a DBR (Distributed Bragg Reflector) reflective layer structure to improve light extraction efficiency. The DBR reflective layer is positioned between the active layer and the GaAs substrate and is composed of multiple alternating layers of materials with high refractive index differences. The introduction of the DBR reflective layer reflects light emitted from the active layer towards the substrate back to the chip's light-emitting direction, effectively improving the light extraction efficiency by 15% to 25%. The number of periods in the DBR reflective layer is set to 20 to 40, the refractive index difference between adjacent layers is controlled within the range of 0.5 to 1.0, and the reflection bandwidth covers the 620nm to 650nm wavelength band.

[0032] The relative positions of the red light enhancement chip and the blue light excitation chip on the LED bracket are optimized according to the optical design. When arranged side-by-side, the spacing between the two chips is controlled within the range of 0.3mm to 0.5mm to ensure that the light emitted by the two chips can be fully mixed in the phosphor material layer. When arranged coaxially, the red light enhancement chip is placed above or to the side of the blue light excitation chip at a specific angle, and the ray tracing simulation is optimized using optical design software. This dual-chip collaborative configuration scheme increases the spectral energy of the red light band by 40% to 60%, effectively improving the color rendering performance of full-spectrum LED chips.

[0033] The red light enhancement chip maintains the same chip size as the blue light excitation chip to optimize package layout. The drive current is set from 350mA to 500mA, the drive voltage from 1.8V to 2.4V, and the output power ranges from 200mW to 400mW. This drive parameter design ensures that the red light enhancement chip provides effective red light supplementation while maintaining low power consumption and heat generation.

[0034] In the design phase of the multi-component fluorescent material system, specifically step 4, the multi-component fluorescent material system is the core component for achieving full-spectrum coverage. Through precise proportioning and synergistic effects, it generates spectral output covering the entire visible light band. This fluorescent material system includes three functionally complementary phosphors: a nitride red phosphor, an aluminate green phosphor, and a silicate green phosphor.

[0035] The nitride red phosphor employs an Eu2+ ion-activated CaAlSiN3 crystal structure with a peak wavelength range of 620nm to 660nm and a half-width of 70nm to 90nm. The CaAlSiN3 crystal structure exhibits extremely high thermal and chemical stability, enabling it to operate for extended periods at 300°C without significant light decay. The Eu2+ ion activator forms unique localized electronic states within the CaAlSiN3 matrix, achieving high-efficiency red fluorescence emission. The quantum efficiency of the nitride red phosphor reaches 75% to 85% at room temperature and remains above 70% at 150°C, effectively ensuring the color stability of the LED chips under high-power operation. The particle size distribution (D50) of the nitride red phosphor is controlled within the range of 8μm to 15μm, a particle size range that ensures both high fluorescence conversion efficiency and good coating processability.

[0036] The aluminate green phosphor employs a Ce3+ ion-activated Lu3Al5O12 crystal structure, with a peak wavelength range of 520 nm to 540 nm and a half-width of 100 nm to 120 nm. The Lu3Al5O12 (lutetium aluminum garnet) crystal structure exhibits extremely high thermal conductivity and good thermal stability, enabling highly efficient green fluorescence emission from the Ce3+ activator within this matrix. The quantum efficiency of the aluminate green phosphor exceeds 90% at room temperature, ensuring efficient conversion of blue excitation light into green visible light. The particle size distribution (D50) of the aluminate green phosphor is controlled within the range of 5 μm to 12 μm, a range suitable for dispersion processes on silicone resin carriers.

[0037] The silicate green phosphor employs an Eu2+ activated Beta-SiAlON crystal structure with a peak wavelength range of 530 nm to 560 nm and a half-width at half-maximum (HWHM) of 50 nm to 60 nm. The Beta-SiAlON crystal structure is a narrow-band emission green phosphor; its narrow HWHM characteristic ensures more continuous and complete spectral coverage in the green light band, effectively filling the spectral gap between the emission peak and the blue excitation peak of the aluminate green phosphor. While the quantum efficiency of the silicate green phosphor exceeds 70% at room temperature, slightly lower than that of the aluminate green phosphor, its narrow-band emission characteristics play an irreplaceable role in improving full-spectrum color rendering performance. The particle size distribution (D50) of the silicate green phosphor is controlled within the range of 3 μm to 8 μm; the smaller particle size facilitates uniform dispersion in coatings.

[0038] The mass ratio of the three phosphors needs to be precisely optimized according to the target color temperature. The mass ratio of nitride red phosphor to aluminate green phosphor is in the range of 1:2 to 1:4, and the mass ratio of silicate green phosphor to nitride red phosphor is in the range of 1:3 to 1:5. This ratio enables the LED light source to cover the entire visible light spectrum from 380nm to 780nm at the target color temperature of 4000K to 6500K. The general color rendering index Ra exceeds 97, and the special color rendering index R9 exceeds 95 and R12 exceeds 90. This color rendering performance meets the stringent requirements for light source color in high-end home lighting, professional color recognition, art display and other fields. After the three phosphors are uniformly mixed, they are dispersed in a silicone resin carrier, with the solid content controlled in the range of 15% to 25%. This solid content range ensures high fluorescence conversion efficiency while ensuring that the fluorescent layer has suitable viscosity and rheological properties to achieve uniform coating.

[0039] In the partitioned coating process design stage, specifically step 5, the partitioned coating process constructs a multi-layer fluorescent structure with spatial gradients on the chip surface to achieve gradual conversion of blue excitation light along the propagation direction, significantly improving light conversion efficiency and effectively controlling the blue light overflow ratio. This coating process coats the fluorescent material in three layers onto the surfaces of the blue light excitation chip and the red light enhancement chip.

[0040] The underlayer is coated with a mixture of nitride red phosphor and aluminate green phosphor, with a red to green phosphor mass ratio of 1:2 to 1:3. This underlayer coating is applied to the perimeter of the chip, covering 80% to 95% of the total chip area. This coverage ensures that the blue excitation light can be fully converted by the underlayer phosphor. The thickness of the underlayer coating is controlled within the range of 40μm to 60μm. This thickness range ensures sufficient phosphor content while avoiding insufficient blue light penetration due to an excessively thick coating.

[0041] The intermediate layer is coated with a mixture of aluminate green phosphor and silicate green phosphor, with a thickness controlled within the range of 30 μm to 50 μm. The width of the intermediate layer coating is 10 μm to 20 μm wider than the underlying layer, forming an extended fluorescence coverage area to improve the uniformity of light conversion efficiency. The mixing ratio of the two green phosphors in the intermediate layer coating is optimized according to the target spectral shape, with a mass ratio of aluminate green phosphor to silicate green phosphor ranging from 3:1 to 5:1.

[0042] A single aluminate green phosphor layer is coated on the top layer, with a thickness controlled between 20 μm and 35 μm. This top aluminate green phosphor layer acts as a spectral shaping layer, performing final color correction and spectral optimization on the mixed light passing through the middle layer. The total thickness of the three phosphor layers is controlled between 90 μm and 145 μm. This total thickness ensures that the phosphor material has a sufficient quantity to achieve efficient light conversion while maintaining good thermal conductivity.

[0043] The partitioned coating structure allows blue excitation light to be progressively converted along the propagation direction, extending the optical path and improving conversion efficiency, while effectively reducing the blue light spillover rate. This multi-layer structure design ensures that the blue excitation light is gradually absorbed and converted as it passes through the bottom and middle phosphor layers, reducing the proportion of unconverted blue light directly spilling out of the package. The blue light spillover rate is controlled within the range of 2% to 5%, significantly lower than the 10% to 15% blue light spillover rate of traditional single-layer coating processes.

[0044] In the packaging structure and optical lens design phase, specifically step 6, the design of these components directly determines the light extraction efficiency, light emission directionality, and long-term reliability of the LED chip. The packaging structure utilizes a high-transmittance silicone resin material with a refractive index controlled within the range of 1.40 to 1.50, achieving a transmittance of over 98% and a Shore hardness in the range of A50 to A70. The refractive index of this silicone resin packaging material is between that of air and the chip material, effectively reducing total internal reflection losses at the interface. Controlling the Shore hardness within the A50 to A70 range ensures that the packaging material possesses sufficient mechanical strength to protect the internal chip and phosphor material, while maintaining a certain degree of flexibility to resist thermal cycling stress.

[0045] The optical lens is made of hemispherical methyl silicone resin, with a radius of curvature controlled within the range of 2.0mm to 3.5mm, a height controlled within the range of 1.5mm to 2.5mm, a center thickness controlled within the range of 0.8mm to 1.5mm, and a bottom diameter controlled within the range of 4.0mm to 5.5mm. The hemispherical lens structure collimates and focuses the light emitted from the chip, significantly improving the directionality of the emitted light and thus enhancing the luminous efficacy of the lamp. The surface roughness Ra of the lens is controlled within the range of 0.1μm to 0.3μm. This surface roughness range effectively reduces light scattering loss while avoiding glare problems caused by an overly smooth surface.

[0046] An air gap of 10μm to 50μm thickness is placed between the lens and the LED bracket to reduce the absorption loss of short-wavelength blue light by the encapsulation material. The low refractive index environment of the air gap (n=1.0) effectively reduces reflection loss at the interface between the encapsulation material and the chip, while isolating heat conduction between the encapsulation material and the chip, reducing the thermal load on the phosphor material. The positioning of the lens and the LED bracket is ensured by a precision mold to guarantee a coaxiality deviation of less than 0.1mm, ensuring that the optical axis of the lens is aligned with the light-emitting center of the LED chip, avoiding problems such as reduced light extraction efficiency and uneven light spot caused by optical axis misalignment.

[0047] In terms of thermal management structure design, aluminum nitride (AlN) is selected as the high thermal conductivity ceramic substrate, with a thermal conductivity ranging from 170 W / (m·K) to 190 W / (m·K) and a thermal resistance controlled within the range of 5 K / W to 10 K / W. Aluminum nitride ceramic possesses the dual advantages of high thermal conductivity and good electrical insulation, making it an ideal heat dissipation substrate material for LED packaging. The silver plating layer thickness of the silver-plated copper alloy support frame is controlled within the range of 3 μm to 6 μm, and the total thickness is controlled within the range of 0.5 mm to 1.0 mm, with a thermal conductivity exceeding 380 W / (m·K). High thermal conductivity silicone grease or solder is used as the thermal interface in the chip bonding area, with a thermal resistance controlled within the range of 0.5 K / W to 2 K / W. The thickness of the die-bonding layer is controlled within the range of 10 μm to 30 μm, ensuring both high thermal conductivity and the density and reliability of the die-bonding layer.

[0048] In terms of die bonding, the blue LED excitation chip is bonded to the positive electrode pad of the LED substrate using gold-tin eutectic bonding. The gold-tin ratio of the gold-tin eutectic solder is set to 80:20 to 79:21 (Au:Sn), and the eutectic temperature is controlled within the range of 280°C to 320°C. The die bonding layer thickness is controlled within the range of 15μm to 25μm, and the die bonding thermal resistance is less than 1.5K / W. Gold-tin eutectic solder has the characteristics of high thermal conductivity (57W / (m·K)) and high reliability, and is the mainstream process solution for LED chip die bonding. The red LED enhancement chip is die bonded to the negative electrode pad of the LED substrate, and the die bonding process parameters are consistent with those of the blue LED excitation chip.

[0049] To verify the technical effect of the full-spectrum high color rendering LED lamp beads of the present invention, a specific application example was designed with a color temperature of 4000K and a color rendering index Ra≥97 as the target parameters.

[0050] For the blue light excitation chip selection, an InGaN blue light chip with a dominant wavelength of 445nm was chosen. The chip size is 0.5mm × 0.5mm, the typical driving voltage at a driving current of 350mA is 3.2V, and the output power is 600mW. The quantum well structure employs eight InGaN / GaN multiple quantum wells, the ITO current spreading layer thickness is 300nm, and the sheet resistance is 20Ω. Under standard test conditions, the chip exhibits a peak luminance of 3200mcd and a emission angle of 130°.

[0051] For the selection of the red light enhancement chip, an AlGaInP red light chip with a main wavelength of 630nm was chosen. The chip size is 0.5mm×0.5mm, the typical driving voltage is 2.1V under a driving current of 350mA, and the output power is 280mW. The DBR reflective layer adopts a 25-cycle AlGaInP / AlAs alternating stacked structure, and the reflection bandwidth covers the 625nm to 650nm band.

[0052] Regarding the formulation of fluorescent materials, the mass ratio of nitride red phosphor (CaAlSiN3:Eu2+) to aluminate green phosphor (Lu3AG:Ce3+) is 1:2.5, and the mass ratio of silicate green phosphor (Beta-SiAlON:Eu2+) to nitride red phosphor is 1:4. After optimization using spectral simulation software, this formulation achieves a spectral distribution at the target color temperature of 4000K that matches natural daylight (D40) by more than 92%.

[0053] Regarding the coating process parameters, the bottom layer thickness was set to 50 μm, achieving 90% coverage; the middle layer thickness was set to 40 μm, 15 μm wider than the bottom layer; and the top layer thickness was set to 28 μm. The total thickness of the three fluorescent layers was 118 μm. Precision dispensing was performed using a metered dispensing machine, with dispensing accuracy controlled within ±2 μm to ensure consistent coating thickness.

[0054] Regarding the packaging process parameters, the silicone-encapsulated lens uses methyl silicone resin with a refractive index of 1.43, a transmittance of 98.5%, and a Shore hardness of A60. The lens has a radius of curvature of 2.8 mm, a height of 2.0 mm, a bottom diameter of 4.8 mm, and a surface roughness Ra of 0.2 μm. The air gap thickness between the lens and the support is set to 30 μm.

[0055] In terms of thermal management design, the aluminum nitride ceramic substrate measures 5.0mm × 5.0mm × 1.0mm and has a thermal conductivity of 180W / (m·K). The silver plating layer of the silver-plated copper alloy support frame is 4μm thick, with a total thickness of 0.8mm. The die-bonding layer uses gold-tin eutectic bonding with a gold-tin ratio of 79:21, has a thickness of 20μm, and a die-bonding thermal resistance of 1.2K / W.

[0056] In terms of performance testing, the main performance indicators of this LED chip under a standard drive current of 350mA are as follows: luminous flux of 145lm to 155lm, luminous efficacy of 130lm / W to 140lm / W, correlated color temperature of 3950K to 4050K, general color rendering index Ra of 97.2, special color rendering index R9 of 96, and R12 of 92. The blue light proportion (the proportion of energy in the 400nm to 500nm wavelength band to the total visible light energy) is 18%, and the blue light hazard level is RG0 (no risk). After operating at 85°C for 1000 hours, the luminous flux maintenance rate is above 95%, and the color coordinate drift Δu'v' is less than 0.002.

[0057] The above specific application examples demonstrate that the full-spectrum high color rendering LED beads designed in this invention can achieve a comprehensive technical effect of excellent spectral quality, high luminous efficiency, low blue light hazard, and high stability. Example

[0058] To meet the personalized needs of different application scenarios, this invention also provides an LED lamp bead design example for high color rendering photographic lighting applications. This application scenario places more stringent requirements on the color rendering performance and spectral continuity of the light source, with a color temperature range covering 3200K to 5600K and a color rendering index Ra of 98 or higher.

[0059] For the selection of the blue light excitation chip, an InGaN blue light chip with a main wavelength of 440nm was chosen, which has a slightly shorter wavelength than that in Example 1 to provide stronger blue light excitation capability. The chip adopts a 10-InGaN / GaN multi-quantum-well structure design, with the In composition controlled within the range of 15% to 18% to optimize the blue light emission wavelength and internal quantum efficiency. The thickness of the ITO current spreading layer was optimized to 350nm, and the sheet resistance was reduced to 15Ω to improve the uniformity of current distribution.

[0060] Regarding the selection of the red light enhancement chip, an AlGaInP red light chip with a main wavelength of 625nm was chosen, which is slightly shorter than that of Example 1 to better match the requirements of photography for the red light sensitive band. The DBR reflective layer was optimized to a stacked structure of 30 cycles, improving the reflection efficiency to over 97%.

[0061] In terms of optimizing the fluorescent material system, the mass ratios of the three phosphors were specifically adjusted to meet the requirements of covering a wide color temperature range from 3200K to 5600K. The mass ratio range of nitride red phosphor to aluminate green phosphor was expanded to 1:1.5 to 1:4, and the mass ratio range of silicate green phosphor to nitride red phosphor was expanded to 1:2 to 1:6. Through this flexible ratio design, a single fluorescent material system can support full-spectrum output within the color temperature range of 3200K to 5600K.

[0062] In terms of optimizing the zoned coating process, the coverage of the bottom layer coating is increased to over 95% to ensure sufficient conversion of blue excitation light. The width difference between the middle layer coating and the bottom layer is increased to 20μm to 25μm to expand the light conversion area. The thickness of the top layer coating is increased to 30μm to 40μm to enhance spectral shaping capabilities. This optimized design achieves a spectral distribution continuity index of over 98%, effectively eliminating the peak-valley discontinuity problem commonly found in traditional LED light sources.

[0063] In terms of encapsulation structure optimization, the silicone-encapsulated lens uses modified methyl silicone resin, with its refractive index increased to 1.46 to enhance the total internal reflection suppression effect. An anti-glare microstructure design is added to the lens surface, with the surface roughness Ra controlled within the range of 0.05μm to 0.1μm to reduce surface glare. This encapsulation optimization improves the light emission uniformity of the luminaire to over 85%, meeting the stringent requirements of professional photographic lighting for light spot uniformity.

[0064] In terms of performance testing, the main performance indicators of this high color rendering LED for photographic lighting are as follows under a color temperature of 3200K: luminous flux of 135lm to 145lm, luminous efficacy of 125lm / W to 135lm / W, general color rendering index Ra of 98.5, special color rendering index R9 of 98, R12 of 96, and R15 (skin tone) of 97. Under a color temperature of 5600K, the main performance indicators are as follows: luminous flux of 150lm to 160lm, luminous efficacy of 135lm / W to 145lm / W, general color rendering index Ra of 98.2, special color rendering index R9 of 97, and R12 of 95. These performance indicators meet the stringent requirements of professional film and television photography and high-end commercial lighting.

[0065] The above embodiments demonstrate that, through systematic optimization of the blue light excitation chip parameters, red light enhancement chip parameters, fluorescent material ratio, and zone coating process, the full-spectrum high color rendering LED beads of the present invention can adapt to the personalized needs of different application scenarios and have broad application prospects in the field of high-end lighting. Example

[0066] To meet the specific spectral requirements of plant lighting applications, this invention also provides a design example of a full-spectrum LED bead for plant growth. The core requirement of this application scenario is to provide spectral energy covering the absorption peaks of plant photosynthesis, while also taking into account the visual comfort requirements of the artificial lighting environment.

[0067] Plant photosynthesis exhibits a bimodal spectral response, with the main absorption peaks located in the blue light band (420nm to 470nm) and the red light band (620nm to 680nm). Furthermore, plants show sensitivity to far-red light (700nm to 760nm), which plays a crucial role in plant morphogenesis and flowering regulation. Traditional plant lighting uses a simplified scheme combining blue light chips with red phosphors, which inherently suffers from limited spectral composition and poor color rendering performance. This invention, through the synergistic design of a multi-component fluorescent material system and a zoned coating process, achieves both satisfactory spectral requirements for plant growth and excellent visual color rendering performance.

[0068] For the selection of the blue light excitation chip, an InGaN blue light chip with a dominant wavelength of 450nm was chosen to provide an excitation wavelength close to the center of the blue light absorption peak during plant photosynthesis. The chip employs an optimized quantum well structure design, with the In composition controlled within the range of 18% to 22% to achieve the target emission wavelength of 450nm. The number of quantum wells is set to 6 to 8 to balance internal quantum efficiency and uniform carrier distribution.

[0069] Regarding the selection of red light enhancement chips, a dual-wavelength red light chip combination scheme is adopted: the main red light chip is an AlGaInP chip with a main wavelength of 630nm to match the center of the red light absorption peak of plant photosynthesis; the auxiliary red light chip is an AlGaInP chip with a main wavelength of 660nm to cover the short-wavelength edge of the red light absorption peak. The two red light chips are arranged side by side on the LED bracket, with the spacing controlled within the range of 0.2mm to 0.3mm to achieve uniform mixing of the light field.

[0070] In terms of optimizing the fluorescent material system, the peak wavelength of the nitride red phosphor was optimized to the range of 640 nm to 650 nm to enhance the energy coverage of the red light band. The peak wavelength of the aluminate green phosphor was maintained in the range of 520 nm to 540 nm to provide the green light component required for plant growth. The peak wavelength of the silicate green phosphor was optimized to the range of 545 nm to 555 nm to fill the spectral gap between red and green light. The mass ratio of the three phosphors was adjusted to 1:1.8:0.3 (red:green:green) to maximize the energy density of the effective spectrum for plant photosynthesis.

[0071] In terms of optimizing the zoned coating process, the bottom layer uses a mixture of nitride red phosphor and aluminate green phosphor, with the proportion of red phosphor increased by more than 30% compared to conventional lighting applications to enhance red light conversion capability. The middle layer uses a mixture of aluminate green phosphor and silicate green phosphor to extend green light band coverage. The top layer uses a combination of aluminate green phosphor and green phosphor of a specific wavelength to optimize the spectral shape. This three-layer zoned structure allows the blue excitation light to undergo a gradual conversion process in the propagation direction, effectively improving the spatial distribution uniformity of fluorescence in each band.

[0072] In terms of packaging structure optimization, the lens design adopts a high light-emission angle hemispherical structure, extending the light-emission angle to 160° to 180° to meet the needs of plant lighting for wide-angle light coverage. The lens material uses high-transmittance methyl silicone resin, with transmittance increased to over 99% to maximize light extraction efficiency.

[0073] In terms of performance testing, the main performance indicators of this plant growth full-spectrum LED bead under a 350mA driving current are as follows: photosynthetic photon flux density (PPFD) is 280μmol / (m²·s) to 320μmol / (m²·s), red-to-blue light ratio (R / B) is 3.5 to 4.5, and photosynthetically active radiation (YPFD) is 230μmol / (m²·s) to 270μmol / (m²·s). While meeting the spectral requirements for plant growth, it generally achieves a color rendering index Ra of over 85 and a color temperature of 4500K to 5500K, providing a visually comfortable lighting environment.

[0074] The above embodiments demonstrate that the technical solution of the full-spectrum high color rendering LED lamp beads of the present invention has good adaptability and scalability. Through system optimization design for specific application scenarios, it can meet the personalized needs of diverse application scenarios such as plant lighting, professional photography, and high-end home furnishing.

[0075] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A full spectrum high color rendering LED lamp bead, characterized in that, Its production method includes the following steps: Step 1, design the LED bracket frame structure: silver-plated copper alloy is selected as the main material of the bracket. Positive and negative electrode pads are set on the bracket frame, and the thickness of the silver plating layer in the positive and negative electrode pad areas is increased; the silver plating treatment of the LED bracket improves the surface reflectivity of the bracket, while ensuring that the bracket has a thermal conductivity not lower than the preset thermal conductivity threshold. Step 2, design parameters for the blue light excitation chip: The blue light excitation chip uses an InGaN material system, sets the main wavelength range to a preset blue light wavelength range, controls the half-width at half-maximum (WWHM) within a preset WWHM range, adapts the chip size to a preset size range, sets the driving current to a preset driving current value, sets the driving voltage to a preset voltage range, and achieves a preset power output range; the blue light excitation chip employs an optimized quantum well structure design to achieve high peak brightness and luminous efficacy, and the emission angle is within a preset angle range; Step 3, design parameters for the red light enhancement chip: The red light enhancement chip uses an AlGaInP material system, sets the main wavelength range to a preset red light wavelength range, controls the half-width at half-maximum (WWHM) within a preset WWHM range, keeps the chip size consistent with the blue light excitation chip to optimize the packaging layout, sets the driving current to a preset driving current value, sets the driving voltage to a preset voltage range, and sets the output power to a preset power range; the red light enhancement chip adopts a high-efficiency structure design to supplement the energy distribution of the LED light source in the red light band; Step 4: Design a multi-component fluorescent material system: The multi-component fluorescent material system includes a nitride red phosphor, an aluminate green phosphor, and a silicate green phosphor; the peak wavelength range of the nitride red phosphor is within a preset red phosphor wavelength range, and the half-width is the preset red phosphor width, exhibiting excellent thermal stability; the peak wavelength range of the aluminate green phosphor is within a preset green phosphor wavelength range one, and the half-width is the preset green phosphor width one; the peak wavelength range of the silicate green phosphor is within a preset green phosphor wavelength range two, and the half-width is the preset green phosphor width two, possessing narrowband emission characteristics to extend the spectral coverage of the green light band; Step 5, Design the partitioned coating process: The partitioned coating process coats the fluorescent material in three layers onto the surfaces of the blue light excitation chip and the red light enhancement chip; the bottom layer is coated with a mixture of the nitride red phosphor and the aluminate green phosphor, with the mass ratio of red phosphor to green phosphor within a preset powder ratio range, and the coating thickness is controlled within a preset bottom layer thickness range; the middle layer is coated with a mixture of the aluminate green phosphor and the silicate green phosphor, with a thickness within a preset middle layer thickness range; the top layer is coated with a single layer of the aluminate green phosphor, with a thickness within a preset top layer thickness range; the total thickness of the three fluorescent layers is controlled within a preset total thickness range; Step 6, Design the encapsulation structure and optical lens: The encapsulation structure uses high-transmittance silicone resin material, with the refractive index controlled within a preset refractive index range, the transmittance reaching a preset transmittance threshold, and the Shore hardness within a preset hardness range; the optical lens uses hemispherical methyl silicone resin material, with the radius of curvature within a preset curvature range, the height within a preset height range, and a preset air gap between the lens and the LED bracket to reduce the absorption loss of short-wavelength blue light by the encapsulation material.

2. The full spectrum high CRI LED lamp bead according to claim 1, characterized in that, In step 2 of the fabrication method, the blue light excitation chip adopts a vertical structure design on a sapphire substrate with an InGaN material system. The thickness of the sapphire substrate is controlled within a preset substrate thickness range. A current spreading layer is set on the upper surface of the chip. The current spreading layer uses an indium tin oxide transparent conductive film to improve the uniformity of current distribution and light extraction efficiency. The emission wavelength of the blue light excitation chip is preset to correspond to the center position of the blue light band, which can effectively excite the fluorescent materials of each component to generate visible light of the target wavelength. The quantum wells of the blue light excitation chip adopt an InGaN / GaN multi-quantum-well structure, and the barrier layer uses GaN or AlGaN material. The number of quantum wells is set to a preset number of wells to optimize the carrier recombination efficiency.

3. The full-spectrum high color rendering LED lamp bead according to claim 1, characterized in that, In step 3 of the fabrication method, the red light enhancement chip adopts a GaAs substrate structure design based on the AlGaInP material system. The thickness of the GaAs substrate is controlled within a preset substrate thickness range. The chip adopts a DBR reflective layer structure to improve light extraction efficiency. The DBR reflective layer is set between the active layer and the GaAs substrate. The emission wavelength of the red light enhancement chip is preset to be within the red light wavelength range of the human eye, which can effectively supplement the energy distribution of the LED light source in the red light band. The relative positions of the red light enhancement chip and the blue light excitation chip on the LED bracket are optimized according to the optical design and can be arranged side by side or coaxially.

4. The full-spectrum high color rendering LED lamp bead according to claim 1, characterized in that, In step 4 of the manufacturing method, the nitride red phosphor adopts a CaAlSiN3 crystal structure activated by Eu2+ ions, and its quantum efficiency reaches the preset quantum efficiency threshold one at room temperature and remains above the preset quantum efficiency threshold two at high temperature; the aluminate green phosphor adopts a Lu3Al5O12 crystal structure activated by Ce3+ ions, and its quantum efficiency exceeds the preset quantum efficiency threshold three at room temperature; the silicate green phosphor adopts a Beta-SiAlON crystal structure activated by Eu2+, and its quantum efficiency exceeds the preset quantum efficiency threshold four at room temperature; the particle size distribution D50 of the three phosphors is controlled within preset particle size range one, preset particle size range two, and preset particle size range three, respectively, to optimize the coating processability and light conversion efficiency.

5. The full-spectrum high color rendering LED lamp bead according to claim 1, characterized in that, In step 4 of the manufacturing method, the mass ratio of the three phosphors is as follows: the mass ratio of nitride red phosphor to aluminate green phosphor is within the preset powder ratio range one, and the mass ratio of silicate green phosphor to nitride red phosphor is within the preset powder ratio range two. This ratio ensures that the LED light source covers the entire visible light spectrum at the target color temperature. Generally, the color rendering index Ra exceeds the preset color rendering index threshold one, and the special color rendering index R9 exceeds the preset color rendering index threshold two. After the three phosphors are uniformly mixed, they are dispersed in a silicone resin carrier, and the solid content is controlled within the preset solid content range to ensure uniform coating of the fluorescent layer.

6. The full-spectrum high color rendering LED lamp bead according to claim 1, characterized in that, In step 5 of the manufacturing method, the bottom layer coating is applied to the area around the chip, covering an area that reaches a preset coverage range of the total chip area, ensuring that the blue light excitation light can be fully converted; the width of the middle layer coating is a preset difference from the width of the bottom layer coating, forming an extended fluorescent coverage to improve light conversion efficiency. The partitioned coating structure allows the blue light excitation light to be gradually converted along the propagation direction, extending the optical path and improving the conversion efficiency, while effectively reducing the proportion of blue light spillover.

7. The full-spectrum high color rendering LED lamp bead according to claim 1, characterized in that, In step 6 of the manufacturing method, the silicone resin encapsulated lens is made of methyl silicone resin, with its refractive index controlled within a preset refractive index range, its light transmittance reaching a preset light transmittance threshold, and its ability to withstand a preset operating temperature range. The lens adopts a hemispherical structure design, with a preset radius of curvature, a preset height range, a preset center thickness range, a preset bottom diameter range, and a surface roughness Ra controlled within a preset roughness range to reduce light scattering loss. The positioning of the lens and the LED bracket is ensured by a precision mold to guarantee that the coaxiality deviation is less than a preset coaxiality threshold, ensuring that the optical axis of the lens is aligned with the light-emitting center of the LED chip. The hemispherical lens structure can collimate and focus the light emitted by the chip, significantly improving the directionality of light output and thus enhancing the luminous efficacy of the lamp. The low refractive index environment of the air gap effectively reduces the absorption loss of short-wavelength blue light by the encapsulation material.

8. The full-spectrum high color rendering LED lamp bead according to claim 1, characterized in that, The manufacturing method further includes step 7, designing a thermal management structure: the high thermal conductivity ceramic substrate in the thermal management structure is made of aluminum nitride, the thermal conductivity reaches the preset thermal conductivity range, and the thermal resistance is controlled within the preset thermal resistance range; the silver plating layer thickness of the silver-plated copper alloy bracket frame is within the preset thickness range, the total thickness is within the preset total thickness range, and the thermal conductivity exceeds the preset thermal conductivity threshold. The die-bonding area of ​​the chip uses high thermal conductivity silicone grease or solder as the thermal interface, and the thermal resistance is controlled within the preset die-bonding thermal resistance range to ensure efficient heat conduction from the PN junction to the ceramic substrate and then to the external heat sink via the copper frame. The positive and negative electrode pads of the LED bracket are made of silver-plated copper alloy, with the silver plating layer thickness within the preset pad thickness range, and the surface roughness Ra of the pads controlled within the preset pad roughness range to ensure good soldering performance and light reflection performance. The blue light excitation chip is die-bonded to the positive electrode pad of the LED bracket via gold-tin eutectic bonding, with the die-bonding layer thickness controlled within the preset die-bonding layer thickness range and the die-bonding thermal resistance lower than the preset die-bonding thermal resistance threshold. The red light enhancement chip is die-bonded to the negative electrode pad of the LED bracket, and the die-bonding process parameters are consistent with those of the blue light excitation chip.

Images