Effect of ytterbia addition on millimeter-wave sintering of aluminum nitride

Abstract

The effect of ytterbia additions on millimeter-wave sintering of aluminum nitride was examined by dependence of densification behavior and thermal conductivity. Nearly full densification was attained by the addition of ytterbia exceeding 3 weight percent. On the other hand, maximum thermal conductivity was obtained at the addition of 3 weight percent ytterbia and excess addition of ytterbia beyond 3 weight percent degraded the thermal conductivity of sintered aluminum nitride. From these results, it is concluded that 3 weight percent addition of ytterbia is the optimum condition for attaining nearly full densification and high thermal conductivity of aluminum nitride sintered at 1,700 C under nitrogen with millimeter-wave heating.