Low‐Temperature Firing and Microwave Dielectric Properties of Ca[(Li_1/3Nb_2/3)_0.84Ti_0.16]O_3−δ Ceramics for LTCC Applications

Abstract

The effects of LiF and ZnO–B2O3–SiO2 (ZBS) glass combined additives on phase composition, microstructures, and microwave dielectric properties of Ca[(Li1/3Nb2/3)0.84Ti0.16]O3−δ (CLNT) ceramics were investigated. The LiF and ZBS glass combined additives lowered the sintering temperature of CLNT ceramics effectively from 1150° to 880°C. The main diffraction peaks of all the specimens split due to the coexistence of the non‐stoichiometric phase (A) and stoichiometric phase (B), which all possess CaTiO3‐type perovskite structures. The transformation from A into B became accelerated with the increase of LiF or ZBS content. ZBS glass restrained the volatilization of lithium salt, which greatly affected the microstructures and microwave dielectric properties. CLNT ceramics with 2 wt% LiF and 3 wt% ZBS sintered at 900°C for 2 h show excellent dielectric properties: ɛr=34.3, Q×f=17 400 GHz, and τf=−4.6 ppm/°C. It is compatible with Ag electrodes, which makes it a promising ceramic for low‐temperature cofired ceramics technology application.

Effect of Bismuth Borate/LiF on the Sintering, Thermal, and Microwave Dielectric Properties of Ba6−3xSm8+2xTi18O54 (x=2/3) Solid Solution

“…2b) shows needle‐like grains with more than 10 μ length along with a few thick grains, which may be due to the secondary phase containing Ba and Ti. The reduction in bulk density can also be due to the porous microstructure resulting from the volatilization of LiF 13,15 . It is found that the addition of BB glass and LiF enhances the growth in the longitudinal direction of the columnar grain significantly, but only slightly in the radial direction.…”

Effect of lithium-based glass addition on the microwave dielectric properties of Ca[(Li1/3Nb2/3)1−xTix]O3−δ ceramics for LTCC applications

“…In order to develop lithium-based complex perovskites for LTCC application, we have selected low loss lithium-based boron-rich multi-component glasses such as lithium borosilicate (35.1Li 2 O-31.7B 2 O 3 -33.2SiO 2 ) (LBS) [24] and lithium magnesium zinc borosilicate (20Li 2 O-20MgO-20ZnO-20B 2 O 3 -20SiO 2 ) (LMZBS) [25] glasses. Few attempts have been made to lower the sintering temperature of the CLNT ceramics by low melting glasses such as B 2 O 3 , B 2 O 3 -Bi 2 O 3 , ZnO-B 2 O 3 -SiO 2 (ZBS) and ZBS-LiF [26][27][28][29][30][31]. However, they have not been investigated the reactivity of the LTCC materials with silver, except in reference [30].…”

“…Few attempts have been made to lower the sintering temperature of the CLNT ceramics by low melting glasses such as B 2 O 3 , B 2 O 3 -Bi 2 O 3 , ZnO-B 2 O 3 -SiO 2 (ZBS) and ZBS-LiF [26][27][28][29][30][31]. However, they have not been investigated the reactivity of the LTCC materials with silver, except in reference [30]. In the present work we have studied the reactivity of the proposed glass ceramic composition with silver for LTCC application and tuned the temperature coefficient of resonant frequency to ±10 ppm/ • C. This paper reports the effect of addition of LBS and LMZBS glasses on the densification, microstructure, chemical reactivity with silver and the microwave dielectric properties of…”

Preparation and properties of low temperature sintered CaO-B2O3-SiO2 microwave dielectric ceramics using the solid-state reaction

“…Due to the increasing demand for microwave and millimeter-wave applications, such as the frontend module for mobile phones, 3G cellulars, wireless local-area networks and radar for automobiles, a lot of attention has been paid to the development of LTCC technology [1][2][3][4][5][6][7][8][9]. Among several LTCC systems, CaO-B 2 O 3 -SiO 2 (CBS) is one of the most important LTCC materials because of its low loss dielectric properties and excellent compatibility with Au, Ag or Cu, as the best high frequency conductors [10][11][12].…”