低介Ba(Al_(0.98)Co_(0.02))_(2)Si_(2)O_(8)-Ba_(5)Si_(8)O_(21)基LTCC微波介质陶瓷的研究

Low Permittivity Ba(Al_(0.98)Co_(0.02))_(2)Si_(2)O_(8)-Ba_(5)Si_(8)O_(21)-Based Microwave Dielectric Ceramics for LTCCs

采用传统固相反应法,按摩尔比合成0.7Ba(Al0.98Co0.02)2Si2O8?0.3Ba5Si8O21(BACSBS)基陶瓷,分析Li2O-B2O3(1wt%)(L-B)烧结助剂对其烧结特性、相组成和微波介电性能的影响,探讨0.7BACS-0.3BS+1wt%(L-B)陶瓷理论与实验介电常数(εr)的差异。结果表明:添加1wt%(L-B)烧结助剂能有效降低0.7BACS-0.3BS基陶瓷的烧结温度(950℃),但严重影响其微波介电性能;在950℃烧结的0.7Ba(Al0.98Co0.02)2Si2O8-0.3Ba5Si8O21+1wt%(Li2O-B2O3)陶瓷具有较好的微波介电性能,其εr=7.56,Q×f=13976 GHz,τf=?6.32 ppm/℃;0.7BACS-0.3BS+1wt%(L-B)复合陶瓷与Ag电极有很好的化学相容性,这为其在LTCC技术的应用奠定了良好的基础。

0.7Ba(Al0.98Co0.02)2Si2O8-0.3Ba5Si8O21(BACS-BS)-based microwave dielectric ceramic was prepared by traditional solid-state reaction method.The effects of Li2O-B2O3(1wt%)(L-B)sintering aids on the microstructure,phase composition and microwave dielectric properties were investigated.Deviation between theoretical and experimental permittivity of 0.7BACS-0.3BS+1wt%(L-B)ceramic was discussed.The results show that adding 1wt%(L-B)sintering aids could decrease the sintering temperature of BACS-BS-based to 950℃.However,it apparently degrades the microwave dielectric properties.0.7Ba(Al0.98Co0.02)2Si2O8?0.3Ba5Si8O21+1wt%(Li2O-B2O3)ceramic could be well-sintered at 950℃and show good microwave dielectric properties:εr=7.56,Q×f=13976 GHz,τf=?6.32 ppm/℃.The good chemical compatibility between the ceramic and Ag electrodes was exhibited,which made it be a promising candidate for the practical applications of LTCC materials.