On the Recycling of Scraps from Process of Silicon-Single-Crystal for Semiconductor as EMC Filler

抄録

To data, the quartz-glassy crucible waste, which is obtained in the production of silicon-single-crystal ingot, has been simply reused as a refractory raw-material, or discarded. The present study is concerned on the advanced recycling-technology, which is based on a micro-particle preparation process in order to produce fine amorphous silica filler for EMC (Epoxy Molding Compound). The paper deals with the physical, chemical and thermal pre-treatment processes to remove impurities effectively, and the micro-particle process for producing the amorphous silica-filler.
The results have shown that, if the contained impurities were eliminated through the application of above mentioned pre-treatment processes, the purity of the product is almost equal to the original anhydrous quartz glass. Therefore, the spent fused glassy crucible has sufficient value for recycling. Examination of the poured ingot has shown that there is no phase transformation of crystallization by the heat treatment (heat hysteresis phenomenon). Since the fused silica is in the amorphous state, the possibility of re-cycling of the material is considered to be very high.