SILICA FINE POWDER, ITS PRODUCTION, AND EPOXY RESIN COMPOSITION FOR SEALING SEMICONDUCTOR

摘要

PURPOSE: To obtain a silica fine powder which gives a suitable sealing material for surface mounting with high productivity by cleaning silica fume as a by- product in the production process of metal silicon with water, specifying the electric conductivity of the extracting water, and then controlling the grain size. CONSTITUTION: This powder is an oxide powder of vapor produced by heating a silica material in the presence of carbon and the oxide powder prepared essentially consists of amorphous silica. For example, an oxide powder essentially comprising amorphous silica is used which is produced as a by-product in the production process of metallic silicon or silicon alloy in an electric furnace. Then the oxide powder is cleaned with water till the conductivity of the water used for extraction becomes <=100μS/cm. Then the grain size of the powder is controlled to obtain a silica fine powder having 0.1-1μm average primary particle size. The obtd. silica fine powder is mixed with an epoxy resin, hardening agent of the epoxy resin (e.g. phenol), and inorg. filler except for the silica fine powder (e.g. alumina) to obtain an epoxy resin compsn. for sealing a semiconductor.