新型SiC晶须增强微晶玻璃基LTCC材料的力学性能调控与增强机理研究

本项目针对目前无源集成封装关键配套LTCC材料力学性能较差及增强机理研究不足具体问题，用溶胶-凝胶法制备可析晶Ca-B-Si-M-O玻璃（CBSM微晶玻璃, M为金属元素）原位包覆SiC晶须形成的“核-鞘”结构CBSM微晶玻璃@SiC晶须LTCC复相材料。通过控制玻璃析晶，期望实现玻璃液相包覆转变为晶相包覆并产生类并联网络结构，讨论玻璃微晶态结构与复相材料力学性能间的影响机制。通过界面层结构解析和原位拉伸测试，探索液相助熔机制下高度取向的SiC晶须对复相材料力学性能增强机理，阐释SiC晶须与晶相/液相间的界面层结合与应力传递、液相连续分布与微气孔填充、渗透反应、SiC晶须的“拔出-桥联”机制及裂纹的扩展-偏转机制等。通过SiC晶须含量与形貌调控，探讨出SiC晶须含量及形貌与复相材料力学性能间的内在影响关系，以改善无源集成封装用LTCC基板的力学性能，并为LTCC材料设计提供全新思路。

This project aims to solve the low mechanical properties and the insufficient research on the reinforcement mechanism of key low temperature cofired ceramic (LTCC) materials used for passive integrated packaging industry via preparing core-sheath CBSM glass@SiC whisker by in situ coating highly-oriented SiC whisker with Ca-B-Si-M-O crystallizable glass (M is a metallic element) by sol-gel method. It is proposed in this project that the reinforcement of LTCC composites can be realized by transforming glass-phase-coating to crystallization-phase-coating and resultantly producing parallel-like network structure in the composites. The influence mechanism between the microcrystalline structure of the glass and mechanical properties of SiC whisker/CBSM glass-ceramics is discussed. Then, based on the analysis of the interface-layer structure and the results of in-situ tensile test, the reinforcement mechanism of highly-oriented SiC whisker on the mechanical properties of CBSM glass-ceramic under liquid phase fluxing condition is explored. The mechanism of interfacial bonding and stress transfer, continuous distribution of liquid phase and filling of micropores, infiltration reaction, pull-out bridging mechanism of SiC whisker, crack propagation and deflection mechanism are explained successively. By adjusting the content and the morphology of SiC whisker, the relationship between the content and morphology of SiC whisker and the mechanical properties of SiC whisker/CBSM glass-ceramics is well discussed, so as to improve the mechanical properties of LTCC substrate for passive integrated packaging and to provide a new idea for the design of superb LTCC materials.