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

Abstract

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. B2O3–Bi2O3–SiO2–ZnO (BBSZ) glass/Al2O3/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 ZnAl2O4 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 (εr = 3.9672, tan δ = 1.49 × 10−3) at 20 GHz. This material has great potential applications in electronic devices.