Filler filler and its manufacturing method, and high thermal conductive insulating material and its manufacturing method

摘要

PROBLEM TO BE SOLVED: To achieve both high thermal conductivity and high electrical insulation, which are contradictory to each other, at a high level. SOLUTION: The filler filler is composed of a mixed powder of a small diameter filler having a small average primary particle diameter D ₁ and a large diameter filler having a large average primary particle diameter D ₂ . The ratio D ₁ / D ₂ of the average primary particle diameter of the small diameter filler to the large diameter filler is 2 × 10 ^{-4 to} 3 × 10 ^-3 , and the volume resistivity of the mixed powder is 2 × 10 ¹⁰ Ω · m or more. Is. Further, the mixing ratio of the small diameter filler is 0.5% by mass to 40% by mass with respect to 100% by mass of the mixed powder. Further, the small-diameter filler adheres to the outer peripheral surface of the large-diameter filler, and the small-diameter filler is connected in a beaded shape in the voids between the large-diameter fillers to form a three-dimensional network structure in the voids by the small-diameter filler. [Selection diagram] Fig. 1