Study On The Preparation Of AlN Material By Microwave Method

AlN ceramic is a new generation substrate material of semiconductor and an ideal semiconductor packing material, but to prepare AlN ceramics with excellent performance,one key point is to produce AlN powder of high purity,detailed granularity, narrow distribution of granularities and steady performance. Under the existing traditional technology condition,the cost of synthesizing high quality AlN powder is very expensive, which greatly restricts the application of AlN materials.Compared to conventional heating, Microwave heating has a lot of advantages such as higher efficiency,free pollution,lower sintering temperature,more uniform material microstructure. Microwave method also helps to obtain advanced materials with special structures or performances. Therefore, microwave technique is becoming one of extremely attractive energy sources in the ceramic industry and has good prospect of development and application.This thesis researched a direct nitrication method to formate AlN powder and to sinter AlN ceramics using microwave heating technology,and systemically studied the influence factors of the carbonize thermal reducing method. We found the most excellent processing parameters of the microwave direct nitricate method on producing AlN powder and AlN ceramics. We also focused on the researches on the mechanisms of this newly method and tried to help to fill up the blanks in this field.The detail research contents included the influences of the direct microwave nitrication process of Al powder,the microwave carbonize thermal reducing process on the preparation of AlN powder and the microwave sintering of AlN ceramics. Among them,the main point is to study the influence factors in microwave carbonize thermal reducing process of synthesizing AlN powder., which included the granularity of Al2O3 and carbon,C/Al₂O₃ mass ratio,loading materials,heating rate,reacting temperature,holding time and so on. And the mechanism of the carbonize thermal reducing reaction under the microwave environment was also discussed to help to find out the suitable processing parameters of industrial producing of AlN powder by microwave carbonize thermal reducing process.