Complex phase transparent ceramic for white-light LED devices and preparation method of complex phase transparent ceramic

Abstract

The invention relates to complex phase transparent ceramic for white-light LED device and a preparation method of the complex phase transparent ceramic. The complex phase transparent ceramic comprises transparent bulk polycrystalline ceramic and second phase particles uniformly distributed in the transparent bulk polycrystalline ceramic, wherein the chemical composition of the transparent bulk polycrystalline ceramic is (CexAyY[1-x-y])3Al5O12, wherein A is at least one of Tb, Pr, Eu, Nd, Tm, and Dy, x is not smaller than 0.0005 and is not larger than 0.03, y is not smaller than 0 and is not larger than 0.9995, the second phase particles are composed of nanometer inorganic oxides with refractive indexes of 2.0-2.5, and the percentage by weight of the second phase particles in the complex phase transparent ceramic is 0.001-50 wt%. According to the invention, the second phase particles are introduced into the complex phase transparent ceramic to form a complex phase structure, the second phase particles have a scattering function, and thus a light path can be adjusted to adjust the illumination angle and the illumination range; meanwhile, the second phase particles have an ultraviolet absorption function, and thus blue light leakage proportion can be adjusted to reinforce the illumination human eye security.

Description

technical field [0001] The invention belongs to the technical field of LED lighting, and relates to a bulk luminous transparent ceramic used in white LED devices. Background technique [0002] White light-emitting diode (White light-emitting diode) has many advantages such as small solidification, shock resistance, instant start and fast response (μs), energy saving and long life (10,000 hours), green and high efficiency, etc., especially in incandescent lamps, fluorescent lamps and The energy efficiency of traditional light sources such as high-pressure gas discharge lamps has almost reached the limit, and the energy efficiency based on LED lighting technology is expected to increase by one to two times in the next 10 years. In the future, it can be widely used in various architectural and landscape lighting, LCD background light, Medical, navigation, aviation, automotive lighting, and various portable lighting are expected to develop into a fourth-generation new lighting s...

AI Technical Summary

Problems solved by technology

[0004] 1) Phosphor powder will produce scattering and absorption when the light emitted by the blue light or ultraviolet chip passes through. Factors such as uneven coating thickness and the shape and particle size of the phosphor powder will cause yellow and blue light spots. Inconsistent white light color temperature and other issues;

[0005] 2) When the fluorescent powder is coated on the blue chip, it needs to be mixed with organic silica gel. Because most of the energy of the LED heats up, the temperature rises. If the silica gel is exposed to high temperature for a long time, the aging of the silica gel will affect the luminous efficiency and reduce the service life of the device.

However, since the ceramic fluorescent board is generally pressed and sintered, there are deficiencies in terms of shock resistance and heat dissipation; the opaque ceramic board also has the problem of light scattering of the phosphor powder, and the design requires the use of thin-layer flip-chip technology (TFFC), so that Design development of new devices has limitations

[0010] Domestic CN1815765A proposes a YAG chip-type white light-emitting diode and its packaging method. It uses a rare-earth-doped YAG chip as a fluorescent material. However, compared with ceramics, single crystal materials have insufficient mechanical and mechanical stability, which limits The flexibility of processing and manufacturing is reduced, and single crystal growth requires high temperature, and the preparation cost is high, and this technical solution still needs to encapsulate the chip with resin, which cannot fundamentally solve the problem of thermal aging of resin

[0011] Another example is CN101338879A, which proposes a method of using YAG transparent ceramics to prepare white light LEDs, but the transparent ceramics in this patent actually refers to the coating layer in the form of polycrystalline particles, and the ceramic particles are 1nm-300nm, rather than bulk ceramics. There is little difference between traditional phosphors

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