A1N陶瓷的低温烧结与组织结构优化

发布时间：2018-06-04 21:58

  本文选题：AlN陶瓷 + 低温烧结　； 参考：《合肥工业大学》2015年硕士论文

【摘要】：随着微电子技术的不断发展,电力电子系统高集成度导致功率密度的提高,器件工作时产生的热量增加,Al203等传统的陶瓷基板已经难以满足电子封装工业对基板越来越高的热耗散性能的要求。由于具有优良的导热、介电及力学性能,AlN陶瓷在电力电子等领域得到愈加广泛的应用。AlN为强共价键化合物,烧结活性很低,AlN陶瓷低温烧结面临很大的困难。本文采用Y2O3-Sm2O3-CaO复合双稀土助烧剂体系,开展A1N陶瓷的低温烧结工艺开发,研究不同助烧剂添加方式及其添加量对AlN陶瓷组成、结构及性能的影响,确定组织结构与性能的关系,实现低温烧结AlN陶瓷的组织结构优化。以脱水硝酸盐的形式添加助烧剂利于其均匀分布,烧结活性高,采用Sm2O3、 Y2O3共同添加的方式,比单一添加相同质量的Sm203促进烧结的效果更好。当稀土氧化物含量为2 wt%时,AlN陶瓷烧结生成CaYAl3O7和CaSmAl3O7第二相；当其含量增加到4 wt%时,其中除形成上述两种第二相外,还形成YAG和SmAlO3反应产物。助烧剂含量为1 wt%Sm2O3、1wt%Y2O3和2 wt%CaO时,1700℃烧结AlN陶瓷的抗弯强度和热导率分别达到321.4 MPa、123.8 W/(m·K)。低温烧结AlN陶瓷的致密度及其晶界第二相的组成、数量与分布状态是影响其性能的关键因素。在低温烧结AlN陶瓷完全致密的前提下,优化烧结助剂的组成与含量,有助于减少AlN陶瓷晶界第二相的量,有利于其在AlN三叉晶界处分布,从而进一步提高AlN的性能。采用脱水硝酸盐的形式添加2wt% Sm2O3、2wt%Y203及1 wt%CaO烧结助剂,并在1750℃烧结制备的AlN陶瓷的第二相主要是YAG和SmAlO3,有少量的CaAl4O7相,AlN陶瓷显微组织结构均匀,断裂方式为沿晶和解理混合断裂形式,主要性能分别为热导率153.7 W/(m·K),抗弯强度402.1 MPa。
[Abstract]:With the development of microelectronics technology, the high integration of power electronic system leads to the increase of power density. The traditional ceramic substrates such as Al203 and other traditional ceramic substrates can not meet the requirements of the electronic packaging industry for the higher and higher thermal dissipation performance of the substrates. Because of its excellent thermal conductivity, the dielectric and mechanical properties of AlN ceramics have been widely used in power electronics and other fields. AlN is a strong covalent bond compound. It is very difficult to sintering AlN ceramics with low sintering activity at low temperature. In this paper, the low temperature sintering process of A1N ceramics was developed by using Y2O3-Sm2O3-CaO compound double rare earth sintering aid system. The effects of different sintering aids and their amount on the composition, structure and properties of AlN ceramics were studied, and the relationship between microstructure and properties was determined. The microstructure of AlN ceramics sintered at low temperature was optimized. The addition of sintering aids in the form of dehydrated nitrate is beneficial to its uniform distribution and high sintering activity. The effect of adding Sm2O3 and Y2O3 together is better than that of single addition of Sm203 of the same quality. When the content of rare earth oxide is 2 wt%, the second phase of CaYAl3O7 and CaSmAl3O7 is formed when the content of rare earth oxide is 2 wt%, and the reaction products of YAG and SmAlO3 are also formed when the content is increased to 4 wt%. The flexural strength and thermal conductivity of AlN ceramics sintered at 1700 鈩，

本文编号：1978968