Denki Kagaku Kogyo Kabushiki Kaisha

Syuji Sasaki

Yasuhisa Nishi

Hiroshi Murata

Keishi Iizuka

Hidetoshi Naito

A semiconductor encapsulation material which exhibits a low viscosity and further improved moldability in encapsulation even when highly loaded with an inorganic filler; an amorphous siliceous powder suitable for the preparation of a resin composition useful as the encapsulation material; and a process for the production of the amorphous siliceous powder. An amorphous siliceous powder having a content of Si and Al of 99.5 mass % or above in terms of oxides, wherein the Al content in the particle size region of 15 &#x3bc;m to less than 70 &#x3bc;m is 100 to 30000 ppm in terms of oxides; the Al content in the particle size region of 3 &#x3bc;m to less than 15 &#x3bc;m is 100 to 7000 ppm in terms of oxides; and the Al content in the whole particle size region is 100 to 25000 ppm in terms of oxides. It is preferable that the (A)/(B) ratio of the Al content (A) in the particle size region of 15 &#x3bc;m to less than 70 &#x3bc;m to the Al content (B) in the particle size region of 3 &#x3bc;m to less than 15 &#x3bc;m be 1.0 to 20.

Amorphous siliceous powder, process for production thereof, resin composition, and semiconductor encapsulation material

A silica powder containing an ultrafine powder in an amount of from 0.1 to 20 mass % and having an average sphericity of at least 0.85, wherein the ultrafine powder has, as the particle size measured by a dynamic light scattering particle size distribution measuring apparatus, an average particle size of from 150 to 250 nm, less than 10 mass % of the ultrafine powder having a particle size of at most 100 nm being less than 10 mass % (not including 0 mass %) and from 10 to 50 mass % of the ultrafine powder having a particle size exceeding 100 nm and not exceeding 150 nm.

Growing community of inventors

Omuta, Japan

Syuji Sasaki