| 摘要 |
The substrate is formed by a plate of boron nitride having a composition of 42% B, 53.5% N2, containing between 1.5 and 2.5% O2, and 1.5% Ca. The surface is increased in hardness and made non-friable by deposition of a glass film to a depth within the range of 10 to 15 microns. This deposit permits surface metallization and ensures cohesion of the boron nitride grains. |
