超低温烧结微波介质陶瓷制备工艺的研究进展

Recent Development on Ultra-Low Firing Technologies of Microwave Dielectric Ceramics

传统方法制备微波介质陶瓷通常需要1000℃以上高温,不仅工艺周期长、能量消耗高,而且难以实现多种材料体系的集成共烧.如今,无线通讯技术的不断革新和蓬勃发展对微波器件小型化、集成化提出了更高要求,低温共烧陶瓷/超低温共烧陶瓷技术被开发和广泛应用.研究烧结温度更低、烧结效率更高,且微波介电性能优异的节能环保型绿色制备工艺,已经成为全球范围内研究热点之一.液相烧结、热压烧结、微波烧结、放电等离子体烧结、闪烧等烧结工艺的提出促进了低温烧结微波介质陶瓷的发展.最近,又出现了一种新的超低温烧结工艺—冷烧结技术.冷烧结具有极低的烧结温度(一般≤300℃)、可在短时间内实现陶瓷高致密化,且在物相稳定性、复合共烧以及晶界控制等方面有着优势,为超低温烧结工艺以及微波介质材料体系的开发提供了新的契机.

Microwave dielectric ceramics prepared via a conventional method usually require a high sintering temperature(i.e.,>1 o0o C)and long sintering time,leading to a high energy consumption and a difficulty to realize the integration and co-firing of multiple material system.Continuous innovation and development of wireless communication technology put forward higher requirements for the miniaturization and integration of microwave devices,so that some technologies for preparing low-temperature co-fired ceramic(LTCC)and ultralow-temperature co-fired ceramic(ULTCC)are developed.Developing green sintering technologies with lower sintering temperatures and higher sintering efficiencies becomes one of the research hotspots.Novel sintering technologies(i.e.,liquid-phase sintering,hot press sintering,microwave sintering,spark plasma sintering,and flash sintering)promote the development of microwave dielectric ceramics.A novel ultra-low temperature sintering technology called cold sintering process is proposed.The sintering temperature of cold sintering process is rather low(≤30o C),which can densify ceramics in a short time,and has some advantages in the phase stability,co-firing of multiple materials and grain boundary manipulation,thus providing an opportunity for the development of ultra-low temperature sintering technology and microwave dielectric material system.