High Performance of Low-Temperature-Cofired Ceramic with Al2O3/BN Biphasic Ceramics Based on B2O3–Bi2O3–SiO2–ZnO Glass

With the rapid development of microelectronic information technology, high-power electronic devices require high heat dissipation. Herein, the preparation of low-temperature cofired ceramic (LTCC) applications with excellent thermal conductivity and dielectric properties is focused. B 2 O 3 –Bi 2 O 3 –SiO 2 –ZnO (BBSZ) glass/Al 2 O 3 /BN green sheets are prepared by tape casting and sintered at 850 °C. The crystal phase composition, microstructure, thermal conductivity, thermal expansion coefficient, and dielectric properties of LTCC are investigated. It is shown that nanoscale rod crystals ZnAl 2 O 4 and Bi are formed in the composite. The generated nanoscale rod crystals build a 3D heat conduction channel in the composite. The thermal conductivity of the sintered sheet with 20 wt% BN is 5.165 W m −1 K −1 . The sintered sheet containing 20 wt% BN has a low coefficient of thermal expansion (2.92 ppm °C −1 ) matched well with silicon and excellent dielectric properties ( ε r = 3.9672, tan δ = 1.49 × 10 −3 ) at 20 GHz. This material has great potential applications in electronic devices.