面向SIP的多K值Li2O-Nb2O5-TiO2系LTCC微波介质陶瓷材料应用基础研究

SIP（System in package）based on LTCC(Low Temperature Co-fired Ceramic) is the most effective method for making the functional intergration module. In addition to the series of permittivities, high Qf value and near-zero resonant frequency temperature coeeficient, the matching between the co-fired materials is also be paid attention to. This project focus on the Li2O-Nb2O5-TiO2 (LNT) system. Based on which, new dielectric ceramic composites with series of permittivities(15～70) are composed of M-phase and Li2TiO3ss phases, to explore the possibility of solving the matching problem radically. By adding the sintering additives matching with the casting process, the LNT-based LTCC microwave dielectric ceramics are supposed to be prepared using the solid-state process. And the effect of the sintering additives on the sintering and dielectric properties, and the low temperature sintering mechanism are going to be clarified. The LNT ceramic performance is supposed to be improved with ionic modification.The relationships bewteen the substitutional ions with the sintering character, phase composition, microstructure and dielectric properties of LNT ceramic are going to be studied. This project provides new ideas for the preparation and performance improvement of the LTCC materials appling for the SIP application, and the experimental basis for the low temperature sintering and ionic modification of the LNT-based LTCC microwave dielectric ceramics. This research has a significance for development of the LNT-based LTCC microwave dielectric ceramic materials.

基于LTCC的SIP是实现功能集成模块最有效技术途径。用于SIP的LTCC材料除了系列化的介电常数、高Qf值、及近零谐振频率温度系数外，材料间共烧匹配性也是研究的热点。本项目拟以Li2O-Nb2O5-TiO2（LNT）材料为研究对象，通过M-Phase和Li2TiO3ss两相复合，制备多K值（K =15～70）LNT系微波介质陶瓷，探索解决材料共烧匹配性问题的可能性；引入与流延工艺匹配的烧结助剂进行降烧实验，阐明烧结助剂对LNT陶瓷烧结性能与介电性能的影响及低温烧结机理；再通过离子置换改善LNT陶瓷性能，揭示代位离子对LNT陶瓷的烧结特性、相组成、微观结构和介电性能的影响规律。为用于SIP的LTCC材料的制备及性能改善提供新的思路，为多K值LNT系LTCC微波介质陶瓷材料的低温烧结及离子改性研究提供实验基础，对研究LNT系LTCC微波介质陶瓷材料的物理机制、发展及应用都具有重要意义。

基于LTCC 的SIP 是实现功能集成模块最有效技术途径。本项目以Li2O-Nb2O5-TiO2（LNT）材料为研究对象，通过Li离子非化学计量比对LNT陶瓷进行了配方设计，利用XRD、SEM、EDS、DSC、介电特性测试仪等相应的分析检测手段，对合成的材料进行析晶分析、相分析、微结构及介电性能分析。实验证明，适量过量的Li含量可将LiNb0.6Ti0.5O3（K60）微波介电陶瓷的温度系数调整为近0,而不牺牲其他性能；而只有将Li的含量降低5wt%时，Li2.081Nb0.243Ti0.676O3（K20）才能获得所需的ss-相陶瓷；而K60与 K20必须按一定比例混合才能得到性能最优的K40陶瓷。同时对M-Phase（K60）和Li2TiO3ss（K20）两相陶瓷的LNT材料及两相复合K40材料制备条件进行了工艺优化，得到了性能最佳的陶瓷基料。采用不同种类的烧结助剂对多K值LNT系列化材料进行降烧研究（烧结温度小于900℃），深入研究了烧结助剂种类及含量以及复合掺杂烧结助剂对陶瓷烧结性能、物相组成、显微结构及介电性能的影响规律。实验证明，LBS降烧剂对LNT系陶瓷有较好的降烧性能，在有效降低烧结温度的同时保证了较好的微波性能。制备的LNT系列LTCC陶瓷在中国电子科技集团公司第十三研究所进行了流延实验，反馈良好，对LNT系列LTCC陶瓷的应用进行了探索。