Use of Titanates to Achieve a Temperature‐Stable Low‐Temperature Cofired Ceramic Dielectric for Wireless Applications

Abstract

A low‐loss and near‐zero temperature coefficient of resonant frequency (Tf) low‐temperature cofired ceramic (LTCC) host dielectric was developed for portable consumer wireless device applications. The low Tf was realized by compensating the Al2O3‐filled‐glass dielectric with admixtures of TiO2 (negative temperature coefficient of dielectric constant (Tɛ)) in the starting formulation. XRD data indicated a portion of the TiO2 in the starting formulation dissolved into the glass, and extensive formation of crystalline titanium compounds was observed via a nucleation and growth mechanism. The dissolution of TiO2 in the glass and subsequent formation of titanium compounds was believed to result in the relatively small amount of TiO2 required to achieve a near‐zero Tf in the final sintered structure.