Ultrafine silicon micropowder for patch discrete devices and preparation method thereof

Abstract

The invention relates to a preparation method of ultrafine silicon micropowder for chip-type discrete devices. The superfine silicon micropowder is used as a filler for chip-type discrete devices. The preparation steps are as follows: select SiO 2 High-purity crystalline quartz sand with a content ≥99.0% is used as the raw material; the raw material is fed into the drum ball mill for grinding after magnetic separation, and the ground material is then classified by the air classifier to obtain D50=1.5-3.5μm, D90=5 ‑8 μm, D 100 = 11-16μm ultra-fine silica powder, used for silicon powder filling of SMD discrete devices. The method of the invention can prepare a silicon micropowder product with specific particle size distribution, regular particle shape and high purity. The product has reasonable particle size distribution, low product viscosity, increased fluidity of epoxy plastics, and improved overflow characteristics. In the SMD discrete device package, the wettability with the chip is better, which effectively solves the electrical problem caused by delamination.

Description

technical field [0001] The invention relates to the technical field of deep processing of inorganic non-metallic materials, in particular to a method for preparing ultrafine fillers for chip-type discrete devices. Background technique [0002] At present, China's semiconductor discrete device industry has already occupied a pivotal position in the international market and maintained a continuous, rapid and stable development. With the continuous heating up of the electronic machine, consumer electronics and other markets, there is still a lot of room for development of semiconductor discrete devices, and the development trend of discrete device packaging technology still takes SMT chip discrete devices as the development direction, towards the direction of miniaturization Developed to meet the needs of miniaturization, light weight and thinning of various electronic equipment. From the commonly used SOT-23, SOD-123 type to smaller size, such as SOT-123 / 923, SOD-723 / 923 and ...

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Problems solved by technology

[0003] New SMT patch discrete devices are used in hot fields such as automotive electronics and energy-saving lighting. New requirements are also put forward for electronic-grade silicon micropowder fillers used in discrete device packaging. The particle size distribution of silicon micropowder fillers currently available on the market is wide. The particle size is large, and it is mainly used for large body packaging types. With the development of discrete device packaging technology towards miniaturization, light weight, and thinning, it is necessary to further reduce the particle size during use to improve the fluidity and overflow characteristics of the corresponding plastic packaging compound. , there is an urgent need for an ultra-fine silica powder that can improve the fluidity and overflow performance of the molding compound. At present, the domestic intermittent ball mill produces ultra-fine powder with low efficiency, low yield, and wide particle size distribution, which cannot meet market needs.

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