Study of temperature effect on microstructures of MCIC ceramic substrate using small angle neutron scattering

The effect of firing temperature on microstructure and dielectric properties of ceramic substrate was studied. The substrate which consists mostly of Al₂O₃ was fabricated using tape casting technique. Three ceramic substrate samples were fired at different temperatures of 1100, 1300 and 1500°C. All samples were characterised for dielectric properties. Pore characterisation was carried out using small angle neutron scattering technique, and X-ray diffraction was used to determine grain growth. The present investigation shows that pore/grain boundary relaxation is the foremost reason of dielectric loss in this Al₂O₃ substrate in the low frequency region and grain size effect (interfacial grain boundary) was concluded to be less significant. This pore/boundary relaxation is found mostly originated from intragranular pore.