| 摘要 |
PROBLEM TO BE SOLVED: To obtain a sintered silicon nitride having excellent strength as well as fracture toughness, a powdery silicon nitride capable of giving the sintered silicon nitride without using a particular sintering method and a circuit board having excellent heat-dissipation performance and useful for electronic part, etc. SOLUTION: This silicon nitride powder contains 70-98wt.% of α-silicon nitride and 2-15wt.% of β-form silicon nitride particles having particle diameter of <=0.6μm in the silicon nitride powder and >=40wt.% based on the total amount of the β-form silicon nitride particles contained in the silicon nitride. The sintered silicon nitride contains silicon nitride particles having distinguishable core part and peripheral part. Yhe silicon nitride particles having a minor diameter of the core part of <=0.5μm account for >=80% (in terms of the number of particles) of the total amount of the silicon nitride particles having distinguishable core part and peripheral part. This circuit board is produced by using the sintered silicon nitride. |
