Abstract:
An object of the present invention is to provide magnesium oxide particles that have a high heat conductivity and excellent properties as heat-dissipating filler, and can prevent problems such as soft errors in the memory. The magnesium oxide particles have a BET specific surface area of 0.1 to 17 m2/g, and an α dose of 0.005 c/cm2·Hr or lower, the particles exhibiting a relation between an X-ray diffraction peak intensity y (cps) at a Bragg angle (2θ) of 42.80° to 43.00° and the BET specific surface area x (m2/g) as represented by the following inequality (1): y≧−960x+33000 (1).