Silica powder in which aggregation is reduced, resin composition, and semiconductor sealing material

Abstract

Provided are a silica powder with a particle size of 2.0 μm or less which does not readily aggregate, has favorable handling, and readily disperses when mixed with a resin; and a resin composition and a semiconductor sealing material comprising the silica powder. The silica powder has a volume-based cumulative size (D50) of 2.0 μm or less and a maximum particle size (Dmax) of 5.0 μm or less as measured by a grind gauge with the following method. (Measurement Method) The degree of dispersion of the silica powder in the epoxy resin is evaluated in a resin composition obtained by adding 67 parts by mass of the silica powder to 100 parts by mass of a bisphenol F-type liquid epoxy resin with a distribution map method using a grind gauge and the maximum particle size (Dmax) is measured in accordance with JIS K 5600-2-5. Further, the same evaluation is performed five times and the average value thereof is employed.

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