Preparation method for semitransparent YAG fluorescent ceramic sheet

Abstract

The invention belongs to the technical field of an illuminating material and especially relates to a preparation method for a semitransparent YAG fluorescent ceramic sheet. The method comprises the following steps: uniformly mixing oxides, such as, yttria and aluminum oxide; mixing adhesive, dispersing agent and precursor and preparing into a biscuit sizing agent; in-situ curing and drying the biscuit sizing agent and then acquiring a biscuit sheet; uniformly coating the biscuit sheet on a mould utilizing a coating tool; standing, airing and then taking off; placing the biscuit sheet into a reducing atmosphere furnace for calcining for 4-7 hours under the calcining temperature at 1300-1800 DEG C, thereby acquiring the required ceramic sheet. According to the invention, the ceramic biscuit is compounded under normal temperature and normal pressure; a high temperature solid phase method is adopted for compounding the ceramic sheet; the fluorescent ceramic sheet is capable of emitting bright white light under the stimulation of 435-450nm blue light and is capable of meeting the illuminating requirement; the prepared ceramic sheet has light, thin and semitransparent characteristics.

Description

technical field [0001] The invention belongs to the technical field of semiconductor lighting, and relates to a method for making translucent YAG fluorescent ceramic sheets driven by high-power LEDs or lasers, in particular to a method for molding fluorescent powder at room temperature with an adhesive, and then heat-treating to prepare translucent method for fluorescent ceramics. Background technique [0002] At present, the process widely used in white light LED packaging is the traditional dispensing process and phosphor coating. The dispensing process is to mix yellow phosphor with epoxy resin or silica gel at a certain There are several obvious disadvantages in this packaging method: 1. When the temperature rises, blue light and ultraviolet radiation will seriously reduce the transparency of the epoxy resin. When the temperature of the device is around 125°C or higher than this temperature, significant expansion or contraction will occur, resulting in additional pressu...

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Problems solved by technology

When the device is around 125°C or higher than this temperature, there will be significant expansion or contraction, resulting in additional pressure on the chip board and leads, resulting in excessive fatigue or even falling off damage

2. Although silica gel has the characteristics of high light transmittance, large refractive index, good thermal stability, small stress, and low hygroscopicity, as the temperature rises, the thermal stress inside the silica gel increases, resulting in a decrease in the refractive index of silica gel. , thus affecting the LED light efficiency and light intensity distribution

The solid-phase method is relatively simple and the process is short, but the production of the biscuit still adopts the mode of mechanical tableting; the liquid-phase method can prepare samples with better quality, but the process is long and time-consuming. There are many influencing factors, and the quality of finished products is difficult to control

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