摘要
随着全球移动数据量的爆炸式增加和全球卫星定位系统(GPS)等其他无线通讯定位手段的飞速发展,微波介质陶瓷作为一种至关重要的介质材料,可以承担多种高频信号和微波信号,正朝着高频化和信号的高频可调性方向发展。当今大数据时代,电子器件的轻薄化、高性能和低损耗对微波介质陶瓷材料提出了更高的要求。低温共烧陶瓷(LTCC)技术以其优异的热、电性能和先进的制备工艺成为有源/无源元器件封装的主流,广泛地用于电子器件和电路封装。实际应用中,对用于基板的微波电子器件而言,低介电常数可以有效地避免信号延迟,保证高效的传输速率,高的品质因数(Q×f≥5000 GHz)可以增加选频特性和器件工作的可靠性,近零谐振频率温度系数(τf)可以保障频率随温度变化的稳定性,低的烧结温度(T s≤950℃)可以实现和低熔点、高电导率的金属共烧。因此,低介LTCC陶瓷成为当前研究的热点,极大促进微波介电材料的应用。微波介质材料可分为陶瓷体系(碲酸盐、钒酸盐、钼酸盐、钨酸盐、硼酸盐和磷酸盐)、微晶玻璃体系(CaO-B_(2)O_(3)-SiO_(2)、MgO-B_(2)O_(3)-SiO_(2)、ZnO-B_(2)O_(3)、MgO-Al_(2)O_(3)-SiO_(2)、Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2)、CuO-B_(2)O_(3)-Li_(2)O)和玻璃+陶瓷复合体系三大类。陶瓷体系一般采用固相法按照化学计量比进行制备。微晶玻璃是一种多晶材料,成分可调,微波介电性能优异,应用广泛。而玻璃+陶瓷复合体系是在低软化点玻璃基体中加入陶瓷填充剂制备出致密度高的微波介质陶瓷,陶瓷填充材料的选择取决于微电子器件的介电需求,主要用于改善微电子器件的介电、热学和力学性能。高性能LTCC材料的研发需要低温烧结介质材料与内电极材料的匹配共烧,从而提高低温烧结介质材料的微波性能和优化低温烧结介质材料的热膨胀系数与热导率。此外,低温烧结介质材料还应具有较好的机械强度和低的生产成本。本文总结了低温共烧低介材料的概念和分类,聚焦于各类共烧陶瓷、微晶玻璃和玻璃+陶瓷复合体系的研究现状与性能特点,系统分析了低温低介共烧材料制备及应用面临的主要问题,展望了其在未来通信技术的应用前景,为今后低烧高性能微波介质材料的发展提供借鉴。
With the explosive increase of global mobile data and the rapid development of global satellite positioning system(GPS)and other wireless communication positioning means,microwave dielectric ceramics,as vital dielectric materials,can bear a variety of high-frequency signals and microwave signals,and are developing towards high-frequency and signal high-frequency adjustability.Lightweight,high performance and low loss are higher requirements for microwave dielectric ceramic materials in the era of big data.Low temperature co-fired ceramic(LTCC)technology has become the mainstream of active/passive component packaging with excellent thermal and electrical properties as well as an advanced preparation process,which is widely used in electronic devices and circuit packaging.In practice applications,for microwave electronic substrates,low permittivity effectively avoids signal delays and ensures efficient transmission rates.Materials with high quality factors(Q×f≥5000 GHz)can increase frequency selectivity and reliability.And the near-zero resonant frequency temperature coefficient(τf)can guarantee the stability of the device operating at different temperatures.The low sintering temperature(≤950℃)enables co-firing with metals with low melting points and high conductivity.Therefore,low dielectric LTCC ceramics have become a current research hotspot,greatly promoting the application of microwave dielectric materials.Microwave dielectric materials can be divided into ceramic systems(tellurite,vanadate,molybdate,tungstate,borate and phosphate,etc.),glass-ceramics(CaO-B_(2)O_(3)-SiO_(2),MgO-B_(2)O_(3)-SiO_(2),ZnO-B_(2)O_(3),MgO-Al_(2)O_(3)-SiO_(2),Li_(2)O-MgO-ZnO-B_(2)O_(3)-SiO_(2),CuO-B_(2)O_(3)-Li_(2)O,etc.),and glass+ceramic composite systems.The ceramic system is generally prepared in a stoichiometric ratio by a solid phase method.Glass-ceramics is a polycrystalline material with adjustable composition and excellent microwave dielectric properties,which has been widely used.The high-density glass-ceramic composite system is prepared by adding a ceramic filler into a low softening point glass matrix,and the selection of the ceramic filler material depends on the dielectric requirement of the microelectronic device and is mainly used for improving the dielectric,thermal and mechanical properties.The research and development of high-performance LTCC materials need the matching co-firing of low-temperature sintered dielectric material and inner electrode material,improving the microwave performance of the low-temperature sintered dielectric material and optimizing the thermal expansion coefficient and thermal conductivity of the low-temperature sintered dielectric material.In addition,it is also considered that the low-temperature sintered dielectric material has good mechanical strength and low production cost.This work summarizes the concept and classification of low temperature co-fired materials with low dielectric permittivity and focuses on the research status and performance characteristics of various types of LTCC ceramics,glass ceramics and glass+ceramic composite systems.In addition,the main problems faced in the preparation and application of low-temperature and low dielectric co-fired materials are analyzed,and the application prospect in future communication technology is discussed,which can provide a reference for the future development of low firing high-performance microwave dielectric materials.
作者
陈国华
黄冰虹
CHEN Guohua;HUANG Binghong(School of Material Science and Engineering,Guilin University of Electronic Technology,Guilin 541004,Guangxi,China;Guangxi Key Laboratory of Information Materials,Guilin University of Electronic Technology,Guilin 541004,Guangxi,China)
出处
《材料导报》
CSCD
北大核心
2023年第20期24-39,共16页
Materials Reports
基金
国家自然科学基金(61865003)。
关键词
5G/6G通讯
微波介质材料
低温共烧陶瓷技术
低介电常数
5G/6G wireless communication
microwave dielectric materials
low temperature co-fired ceramic technology
low dielectric constant
