Transparent ceramic white light emitting diode (LED) and preparation method thereof

Abstract

The invention provides a transparent ceramic white light emitting diode (LED), which comprises a bracket, a blue LED chip and cerium-doped yttrium aluminum garnet transparent ceramic wafer, wherein the chemical formula of a material of the cerium-doped yttrium aluminum garnet transparent ceramic wafer is (Y1.xCex) 3Al5O12; and in the formula, x is greater than or equal to 0.0005 but less than or equal to 0.005. A packaging method of the transparent ceramic white LED comprises the following steps that: (1) the blue LED chip is put into a groove arranged in the bracket; (2) a gold wire of the blue LED chip is welded with an electrode mounted at the bottom of the bracket; (3) silica gel is filled into the groove of the bracket, and the cerium-doped yttrium aluminum garnet transparent ceramic wafer is covered on the silica gel so as to combine the members; and (4) a combined body formed in the step (3) is baked at a temperature of 100 DEG C to 120 DEG C until the silica gel is cured, and after the silica gel is cured and the cerium-doped yttrium aluminum garnet transparent ceramic wafer and the blue LED chip are fixedly arranged on the bracket, the transparent ceramic white LED is formed.

Description

technical field [0001] The invention relates to the field of white light LEDs, in particular to a transparent ceramic white light LED and a preparation method thereof. Background technique [0002] Semiconductor lighting based on light-emitting diodes (LEDs) is the most promising high-tech field in the 21st century. As a novel semiconductor light source, white light LED has really ignited the "brilliance of green lighting" with its remarkable advantages of high efficiency, low power consumption, long life, solid state energy saving and green environmental protection, which is unmatched by many traditional light sources. , so it has broad application prospects. Its application fields include liquid crystal display (LCD) backlight (car, audio instrument panel, mobile phone backlight), traffic signal lights, indoor lighting, square lighting, etc. Due to the rapid development of the mobile phone and automobile industries and the demand of the general lighting market, people's ...

AI Technical Summary

Problems solved by technology

The particle size of commonly used phosphors is above 1um, and the refractive index is greater than or equal to 1.85, while the refractive index of potting silica gel is generally around 1.5. Due to the mismatch of the refractive index between the two, and the particle size of phosphors is much larger than the light scattering limit, so in the fluorescent There is light scattering on the surface of powder particles, which reduces the light extraction efficiency

[0005] 2. Poor heat resistance

As the temperature rises, the quantum efficiency of the phosphor decreases, the light output decreases, and the radiation wavelength will also change, which will cause changes in the color temperature and chromaticity of white LEDs. Higher temperatures will also accelerate the aging of phosphors.

The reason is that the phosphor coating is made of epoxy or silica gel and phosphor, which has poor heat dissipation performance. When it is irradiated by purple or ultraviolet light, it is prone to temperature quenching and aging, which reduces the luminous efficiency.

[0006] 3. Poor cooling performance

The problem with this method is that the lattice constant and refractive index of the phosphor powder and the ceramic powder do not match, so they cannot completely dissolve each other during the sintering process, and the uniformity and light transmittance of the prepared transparent ceramics are not high, resulting in poor packaging. The emitted light of white LED lights is unevenly distributed in space, and the light extraction rate is not high

Although the patent replaces the fluorescent powder with a bulk transparent ceramic luminous body, although the scattering of light is effectively reduced and the luminous efficiency is improved. Compared with the preparation of single crystal materials, the process is simpler, but the patent does not disclose the bulk transparent The composition of the ceramic luminous body does not disclose the luminous efficiency of its transparent ceramic white light LED device, and the composition of the transparent ceramic luminous body is one of the important factors for the improvement of luminous efficiency

In addition, its LED chip is located at the bottom of the groove opened by the carrier, and the transparent ceramic luminous body directly stacked on the LED chip cannot realize their fixation on the carrier, which will also affect the normal operation and service life of the transparent ceramic white light LED device. , the inlaying of LED chips on the carrier will increase the preparation process of the carrier

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