Patent ID: 8973888
Filing Date: 2015-03-10
Classification: B29C,C01B,C01P,C30B,Y10T

Abstract:
1. A method for producing a polycrystalline silicon ingot casting mold having a release layer, comprising: forming a slurry by mixing a silicon nitride powder with water, the silicon nitride powder being obtained by blending a silicon nitride powder (A) having a short axis average particle diameter of 0.6 to 13 μm and an oxygen content of 0.3 to 1.0% by weight with a silicon nitride powder (B) having a short axis average particle diameter of 0.1 to 0.3 μm and an oxygen content of 1.3 to 20% by weight at a weight ratio of 5:5 to 9:1, coating a surface of the mold with the slurry, and heating the mold at 400 to 800° C. in an atmosphere containing oxygen, after coating the slurry.