Dielectric, Mechanical, and Thermal Properties of Low‐Permittivity Polymer–Ceramic Composites for Microelectronic Applications

A new low‐permittivity polymer–ceramic composite for packaging applications has been developed. The ceramic‐reinforced polyethylene and polystyrene composites were prepared by melt mixing and hot molding techniques. Low‐loss, low‐permittivity Li ₂ MgSiO ₄ (LMS) ceramics prepared by the solid‐state ceramic route were used as the filler to improve the dielectric properties of the composites. The relative permittivity and dielectric loss were increased with the increase in the ceramic loading at radio and microwave frequencies. The mechanical properties and thermal conductivity of the Li ₂ MgSiO ₄ ‐reinforced polymer–ceramic composite were also investigated. The stability of the relative permittivity of polymer–ceramic composites with temperature and frequency was investigated. The experimentally observed relative permittivity, thermal expansion, and thermal conductivity were compared with theoretical models.