Si3N4 whisker/MPPO composite substrate with low dielectric loss and high thermal conductivity

Si 3 N 4 –MPPO copper clad substrates with different volume fraction of β-Si 3 N 4 whisker were prepared by hot pressing process. The effects of the loading fraction of β-Si 3 N 4 whisker fillers on the dielectric frequency and temperature response characteristics, thermal conductivity, thermal expansion coefficient, and mechanical strength were evaluated. It is found that the dielectric permittivity of the composite increases with the increase in fraction of Si 3 N 4 whisker as expected, which follows the modified Kerner model well. The composites with low loading fraction of filler (