用于Ka波段输能窗的AlN窗片及封接技术研究

Research on Aluminum Nitride Ceramics and Sealing Technology for Ka-Band Microwave Windows

本文研制了高导热低损耗的AlN陶瓷,制备的AlN陶瓷介电常数8.4,损耗角正切5×10^-4,常温热导率为186W/(m·K);同时研制出了热导率为192W/(m·K)的氮化铝陶瓷。完成了AlN的陶瓷金属封接工艺,封接件抗拉强度大于78MPa,制备了AlN陶瓷输能窗,钎焊后的AlN陶瓷金属封接件及输能窗检漏结果均气密,氦漏率小于1×10^-11Pa·m^3/s。本文研制的AlN陶瓷及封接工艺不但满足输能窗用介质材料的性能要求,还可以应用于微波管收集极及夹持杆等方面。

High thermal conductivity and low loss tangent AlN ceramics are prepared,which have dielectric constant of 8.42,loss tangent of 5×10^-4 and thermal conductivity of 186 W/(m·K)at room temperature.AlN ceramics with thermal conductivity of 192 W/(m·K)are also prepared.An AlN ceramic-metal sealing process is developed.With this process,the tensile strengths of the sealed parts are greater than 78 MPa.AlN microwave windows are prepared.The brazed AlN ceramic-metal parts and the microwave windows are hermetic,and the leakage rates of them are all less than 1×10^-11 Pa·m^3/s.The developed AlN ceramics and sealing process not only can meet the requirements of microwave windows,but also can be applied to collectors and support rods of microwave tubes.