固有烧结温度低的低介电常数陶瓷材料研究进展

固有烧结温度低的低介电常数微波介质陶瓷材料在低温共烧陶瓷(LTCC)中具有重要的应用前景。着重介绍了钨酸盐、磷酸盐、碲酸盐、钼酸盐、钒酸盐、铌酸盐和硼酸盐等固有烧结温度低的低介电常数微波介质陶瓷材料的研究进展,并指出低温共烧陶瓷材料目前存在的问题。     

硼硅酸盐玻璃的低温烧结研究

莫来石陶瓷材料作为高性能集成电路的候选材料,在电子封装基片领域有着广阔的应用前景,但过高的烧结温度限制了其发展。本文利用溶胶-凝胶法制备能够在低温实现烧结的硼硅酸盐玻璃,作为引入相以实现莫来石陶瓷封装材料的低温共烧,通过研究CaO、B2O3、SiO2的不同组成并引入ZnO、P2O5作为助烧剂,最终制得了能够在800℃实现低温烧结的硼硅酸盐玻璃,其线性收缩率约为22.4%~24.0%,表观密度为2.21±0.1,ε=4.1±0.2,tgδ<0.06%,Rj>1.0×1012Ω.cm。     

BaO-TiO2-B2O3-SiO2体系LTCC介电性能的研究

利用预煅烧法制备了BaO-TiO2-B2O3-SiO2体系低温共烧陶瓷(简称LTCC)材料,其烧结温度在900℃以下,介电常数在4～20之间随组成变化而调节,介电损耗能保持在0.002左右的水平;研究发现,玻璃陶瓷材料的原始组成、烧结体致密度和电场频率等是影响介电常数的主要因素;而影响介电损耗大小的相关因素比较复杂,本文研究认为材料的原始相组成、烧结体相组成、体电阻率、温度及电场频率等因素起主要作用;研究结果进一步表明,LTCC烧结体的介电损耗与烧结致密度没有明显的联系.     

TiB2陶瓷活化烧结及制备技术

TiB2材料具有高熔点、高硬度、耐磨、耐腐蚀、抗氧化以及导电性好和导热性好等优点,是一种具有广泛应用前景的新型陶瓷材料.但是其极强的共价键晶体结构和较低的自扩散系数,使得其很难获得致密的陶瓷材料.主要从添加助烧剂和烧结技术两方面介绍了TiB2陶瓷活化烧结方法的研究进展,并分析了该技术促进材料烧结致密化的机制,同时介绍了热压烧结和放电等离子(SPS)烧结技术.     

冷烧结技术的研究现状及发展趋势

采用常规热烧结实现陶瓷粉体的致密化,烧结温度通常超过1000℃,这不仅需要消耗大量能源,还会使一些陶瓷材料在物相稳定性、晶界控制以及与金属电极共烧等方面面临挑战。近年来提出的冷烧结技术(Cold Sintering Process,CSP)可将烧结温度降低至400℃以下,利用液相形式的瞬态溶剂和单轴压力,通过陶瓷颗粒的溶解-沉淀过程实现陶瓷材料的快速致密化。冷烧结技术具有烧结温度低和时间短等特点,自开发以来受到广泛关注,目前已应用于近百种陶瓷及陶瓷基复合材料,涉及电介质材料、半导体材料、压敏材料和固态电解质材料等。本文介绍了冷烧结技术的发展历程、工艺技术及其致密化机理,对其在陶瓷材料及陶瓷-聚合物复合材料领域的研究现状进行了综述,其中根据溶解性的差异主要介绍了Li₂MoO₄陶瓷、ZnO陶瓷和BaTiO₃陶瓷的冷烧结现状。针对冷烧结技术工艺压力高的问题及可能的解决途径进行了探讨,并对冷烧结技术未来的发展趋势进行了展望。     

LTCC微波介质陶瓷的研究进展

在介绍低温共烧陶瓷(LTCC)技术的基础上,阐述了LTCC技术对微波介质陶瓷的性能要求.综述了ZnO-TiO2、ZnNb2O6、Te基等常用的LTCC材料体系及超低温(≤700℃)烧结微波介质陶瓷体系.目前存在的问题是传统的降温方法很难实现材料高性能与低烧结温度的完美结合,因此在今后的发展中应致力于解决这一问题并研究开发LTCC系列化材料.另外,寻找新型固有烧结温度低的材料体系是未来发展的方向之一.     

微波介质陶瓷低温共烧技术的研究进展

介绍了低温共烧陶瓷技术(LTCC)的特点及低温共烧技术对微波介质陶瓷的性能要求.总结了微波介质陶瓷实现低温共烧的主要方法,详细综述了典型微波介质陶瓷低温共烧技术的研究进展,指出了其目前存在的问题,并针对微波介质陶瓷低温共烧技术的发展方向提出了看法.     

低温共烧陶瓷材料基板用玻璃/萄化铝吕复合材料的制备及性能研究

一、背景近年来,随着现代通讯技术的迅速发展,特别是移动通讯设备不断向低成本、小型化、轻量化、高稳定与频率系列化方向发展,人们对微波介质陶瓷材料提出了更高的要求,使得微波介质陶瓷材料不断朝着频率系列化且与低熔点金属银(Ag)或铜(Cu)共烧的烧结温度低的环保型材料发展。     

关于不同粒度粉末层间烧结收缩不同步问题的探讨

在利用粉末烧结法制备梯度功能材料的过程中,会涉及到不同材质或同材质不同粒度粉末共同烧结的问题.主要结合多孔材料和膜材料的烧结,对现有实现共同烧结的技术进行对比,着重介绍了通过调整烧结工艺以达到共烧的方法,并对该技术的发展进行了展望.     

低温共烧氧化铝/玻璃复合基板材料的研究

以低软化点的钙硼硅酸盐玻璃和氧化铝粉末为原料,制备了氧化铝/玻璃低温共烧复合基板材料。所需的玻璃粉体采用溶胶-凝胶法制备。研究了烧结温度和氧化铝含量对复合材料的烧结特性、介电性能以及力学性能的影响。结果表明,当氧化铝质量分数为50%,复合材料经950℃、保温2 h烧结后,其εr=5.92,tanδ=5.7×10-4,ρ=1012Ω.cm,抗弯强度σ=167.82 MPa,热膨胀系数α=4.86×10-6/℃,可望作为低温共烧多层陶瓷基板材料应用。     

Low-temperature sintering and ferrimagnetic properties of LiZnTiMn ferrites with Bi2O3–Nb2O5 eutectic mixture

Journal of Materials Science: Materials in Electronics - In order to investigate the sintering temperature requirements of low-temperature co-fired ceramics (LTCC) technology, the effects of...     

Microstructures and Dielectric Properties of Ba1-xSrxTiO3 Ceramics Doped with B2O3-Li2O Glasses for LTCC Technology Applications

Ba1-xSrxTiO3 ceramics, doped with B2O3-Li2O glasses have been fabricated via a traditional ceramic process at a low sintering temperature of 900 ℃ using liquid-phase sintering aids. The microstructures and di- electric properties of B2O3-Li2O glasses doped Ba1-xSrxTiO3 ceramics have been investigated systemat- ically. The temperature dependence dielectric constant and loss reveals that B2O3-Li2O glasses doped Ba1-xSrxTiO3 ceramics have di?usion phase transformation characteristics. For 5 wt% B2O3-Li2O glasses doped Ba0.55Sr0.45TiO3 composites, the tunability is 15.4% under a dc-applied electric field of 30 kV/cm at 10 kHz; the dielectric loss can be controlled about 0.0025; and the Q value is 286. These composite ceramics sintered at low temperature with suitable dielectric constant, low dielectric loss, relatively high tunability and high Q value are promising candidates for multilayer low-temperature co-fired ceramics (LTCC) and potential microwave tunable devices applications.     

低温共烧陶瓷无源集成技术及其应用

低温共烧陶瓷技术是近年发展起来的令人瞩目的整合组件技术,已经成为无源集成的主流技术,成为无源元件领域的发展方向和新元件产业的经济增长点.介绍了目前LTCC无源集成技术及其国内外研究动态和应用前景.     

Effects of Pb–B–Si–O glass on the microstructures and electrical properties of silver electrode for LTCC application

The co-firing compatibility between green tape and the Ag electrode is a crucial characteristic in low-temperature co-fired ceramic (LTCC) technology and plays a vital role in improving the performance and application status of LTCC device modules. In this work, we studied the effects of lead content on the glass viscosity, the microstructure, and co-firing compatibility of silver electrode film. It was found that the softening point and viscosity of the glass were decreased, and the wettability between the glass and silver was improved with the increase of the lead content, which promoted the co-firing densification and interfacial bonding between the silver electrode film and the ceramic layer. The film presented the best electrical properties co-firing at 875 °C for 15 min, with the resistivity of 1.21 mΩ/sq. And the film was densified. The sintering interface was clear and well bonded. The results showed that an appropriate lead content in glass could effectively improve the interfacial bonding and the electrical properties during co-fired process, providing a new control methodology for realizing co-fired matching of the silver electrode film with low-temperature co-fired ceramics.

     

氧化物陶瓷闪烧机理及其应用研究进展

闪烧是近些年广受关注的一种电场辅助烧结技术。本文介绍了闪烧的起源与发展, 并对闪烧的基本特征进行了分析。在闪烧孕育与引发过程的研究方面, 发现了孕育阶段的非线性电导特征和电化学黑化现象, 提出了氧空位主导的缺陷机制; 在闪烧阶段的快速致密化研究方面, 提出了电场作用导致的缺陷产生和运动会在粉体颗粒间产生库仑力, 有利于烧结前期的致密化过程, 同时发现闪烧致密化过程中还伴随着金属阳离子的快速运动; 在闪烧阶段的晶粒生长和微结构演变方面, 发现了试样温度沿电流方向呈非对称分布, 试样中间位置的晶界迁移率明显提高, 提出电化学缺陷对微观结构有重大影响。基于上述研究成果, 本团队利用电场作用下出现的低温快速传质现象, 发展了陶瓷闪焊技术, 实现了同种陶瓷/陶瓷、陶瓷/金属, 甚至异种陶瓷/陶瓷之间的快速连接; 发展了陶瓷闪烧合成技术, 不仅实现了典型氧化物陶瓷的快速合成, 而且实现了高熵陶瓷和具有共晶形貌的氧化物陶瓷的快速合成; 发展了氧化物陶瓷的电塑性成形技术, 初步实现了氧化锆陶瓷低温低应力下的快速拉伸和弯曲变形。本文最后总结了闪烧机理研究面临的挑战, 并从焦耳热效应和非焦耳热效应两方面展望了闪烧的发展方向, 期望对闪烧技术在国内的发展有所裨益。     

微波介质陶瓷的中低温烧结

综述了近年来微波介质陶瓷在低温烧结方面的研究进展.为降低微波介质陶瓷的烧结温度,传统的方法是添加氧化物或低熔点玻璃作为烧结助剂、采用化学合成方法和使用超细粉体作为起始原料.另外,发展具有低烧结温度的新的微波介质陶瓷材料体系也是一种有效的方法.     

Co-Firing Characteristics of Cordierite Tapes with Ag/Pd for High Frequency Chip Inductors

As a new electronic material, low-temperature sintering, low-dielectric cordierite tapes exhibit great potential in the manufacturing of high frequency inductors. While the co-firing of cordierite dielectric material with conductive metal in lower sintering temperature is always a difficulty, and it directly affects the practical application of the inductors. In this paper, the prepared cordierite tapes with low-sintering temperature, low dielectric constant, and low losses were used as matrix material, and the co-firing characteristics of cordierite tapes with Ag/Pd was preliminary studied to investigate the feasibility in the manufacturing process. Deformation, pores, and delaminations are three main defects of the co-fired samples. With an Al₂O₃ powders and press blocks assisted process, good co-firing effect of cordierite tapes with Ag/Pd can be obtained at 900 °C. The co-firing interface of cordierite tape and Ag/Pd is very dense and no obvious element migration is detected. The paper is contributed to the manufacture of high frequency inductors.     

Co-firing preparation and properties of piezoelectric ceramic/structural ceramics layered composites

Pb(Zr, Ti)O₃(PZT)-based piezoelectric ceramics and Al₂O₃-based structural ceramics were cast and co-fired to prepare a layered piezoelectric ceramic/structural ceramic composite. Considering the significant differences in sintering characteristics of PZT- and Al₂O_3-based ceramics, control of the sintering temperature and the dependence of the linear shrinkage on the solid content of the tape-casting films were systematically conducted at first. The sintering density and the interface bonding properties of the prepared composites were then investigated. The results of electrical and mechanical properties of the composite ceramics indicate: By using sintering aids, Al₂O₃ ceramic could be fully densified and co-fired with PZT ceramic at 1150 °C. Shrinkage matching during sintering was achieved by adjusting the solid contents to 45 vol.% and 65 vol.% for PZT and alumina tape-casting films. In the layered composites, Al₂O₃ structural ceramic presents an excellent mechanical property with HV hardness of 667, while the PZT functional ceramic presents d₃₃, ε_r and tanδ of 259 pC/N, 965 and 0.37%, respectively.

     

Effects of Li2O3–B2O3–SiO2 addition on dielectric properties and microstructure of MgO–TiO2–ZnO–CaO ceramics

The effect of Li₂O₃–B₂O₃–SiO₂ (LBS) liquid-phase additives on the sintering, microstructures, and dielectric properties of MgO–TiO₂–ZnO–CaO (MTZC) ceramics was investigated. It was found that the sintering temperature could be lowered easily, and the dielectric properties of MTZC ceramics could be greatly improved by adding a small amount of LBS solution additives. With the addition of 10 wt% LBS, the ceramics sintered at 900 °C showed favorable dielectric properties with ε_r = 21.7, Qf = 5.0 × 10⁴ GHz, and TCF = ?21.6 ppm/ °C. The distructive physical analysis showed an excellent co-firing interfacial behavior between the MTZC ceramic and the Ag electrode. It indicated that MTZC ceramics with LBS solution additives have a number of potential applications on passive integrated devices based on the low-temperature co-fired ceramics technology.