Patent Number: 6,168,859

Title: Filler powder comprising a partially coated alumina powder and process to make the filler powder

Abstract: A filler powder comprised of an alumina powder coated with a silicon containing coating, wherein the silicon containing coating at most partially covers the surface of said coated alumina powder and the filler powder, when mixed with a thermosetting epoxy resin, has an average spiral flow length that is at least about 1.1 times greater than a comparable filler powder containing uncoated alumina powder mixed with the thermosetting resin. A preferred process for making the filler powder comprises: heating, simultaneously, an alumina powder with a second powder coated with an organo-silicate to a temperature for a time sufficient to volatilize, deposit and pyrolyze at least a portion of the organo-silicate on the alumina powder to form a silicon containing inorganic coating thereon.

Inventors: Mills; Lynne K. (Midland, MI), Swedberg; Eric J. (Midland, MI), Knudsen; Arne K. (San Diego, CA)

Assignee: The Dow Chemical Company

International Classification: C04B 41/45 (20060101); C04B 41/81 (20060101); C08K 9/00 (20060101); C08K 9/06 (20060101); H01L 23/29 (20060101); H01L 23/28 (20060101); B32B 005/16 ()

Expiration Date: 01/02/2018