MULLITE SINTERED COMPACT, METHOD FOR PRODUCING SAME, AND COMPOSITE SUBSTRATE

摘要

This mullite sintered compact has an impurity element content not exceeding 1mass%, wherein the average particle diameter of the mullite sintered particles does not exceed 8μm, and the average maximum length of the pores which are present on the polished surface does not exceed 0.4μm. The center average roughness (Ra) of the surface is preferably 3nm or less. The maximum height (Rp) of the surface is preferably 30 nm or less. The number of pores present on the surface should preferably not exceed 10 per unit of area measuring 4μm x 4μm.