基于冷烧结技术的微波介质陶瓷研究进展

微波介质陶瓷作为介质材料被广泛应用于物联网、工业互联网、5G通信、全球卫星通信系统的无源器件中。从微波介质陶瓷的研究背景出发,介绍了冷烧结的致密机理和工艺参数,总结了冷烧结微波介质陶瓷的主要材料体系和器件,指出了冷烧结微波介质陶瓷的主要问题和发展前景。冷烧结技术具有烧结温度低(<300℃)、可共烧异质材料、烧结前后晶粒尺寸差异小、制备工艺简单、节能环保等多种优点,在多层共烧陶瓷和微波系统集成方面具有潜在应用。     

高介电常数微波介质陶瓷及其低温烧结的研究进展

高介电常数微波介质材料是实现现代微波通信器件要求的微型化、集成化发展趋势的重要材料,针对多层结构设计的器件要求,需要微波介质陶瓷能与高电导率电极实现低温共烧。本文综述了近年来高介电常数微波介质陶瓷及其低温烧结研究的最新进展,指出进一步提高陶瓷的介电常数和研究新型低温烧结助剂是今后发展的趋势。     

电子陶瓷材料在多芯片组件(MCM)中的应用

论述了电子陶瓷在多芯片组件（MCM）中的应用、性能要求及优点。重，最叙述低温共烧陶瓷基板技术以及A1N陶瓷基板材料的合成与优异性能。     

YSZ/Al2O3/YSZ多层陶瓷叠层制备方法的研究

本文分别采用三种叠层方式制备YSZ/Al2O3/YSZ多层陶瓷,通过实验得出:由于YSZ与Al2O3陶瓷烧结性能的差异,导致YSZ与Al2O3陶瓷叠层共烧时容易分层翘曲,YSZ与Al2O3主要依靠层间的物理啮合作用而结合。通过在流延YSZ层与丝网印刷Al2O3层之间增加印刷YSZ过渡层的叠层方法,可以改善YSZ流延层与Al2O3丝网印刷层之间的结合,而得到结合良好的YSZ/Al2O3/YSZ多层陶瓷共烧结合界面。     

多层复合BZN电介质/Ni-Zn-Cu铁氧体的共烧行为

由ＢＺＮ介电陶瓷与Ｎｉ－Ｚｎ－Ｃｕ铁氧体构成多昨合体,借助ＸＲＤ,ＳＥＭ,ＥＤＳ和ＴＭＡ等技术研究了共烧过程中两种材料界面的相互作用和共烧行为,结果表明,共烧过程缴散导致界面附近材料相结构和发生明显变化,两种材料烧成动力学失配造成共烧体中产生裂纹等缺陷。     

Sol—gel法制备低温共烧多层陶瓷基板用高硅玻璃

本文介绍了Ｓｏｌ－ｇｅｌ法制备低温共烧多层陶瓷基板用高硅玻璃粉技术，研究了这种高硅玻璃及其瓷料的有关性能。     

超低温烧结微波介质陶瓷制备工艺的研究进展

传统方法制备微波介质陶瓷通常需要1 000℃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。     

玻璃／陶瓷体系低温共烧陶瓷的研究进展

低温共烧陶瓷（LTCC）是现代做电子封装中的重要组成部分,因其性能优良而得到了广泛应用。LTCC基板材料可以分为玻璃／陶瓷体系和微晶玻璃体系两大类。本文叙述了玻璃／陶瓷体系低温共烧陶瓷的材料组成、研究现状、存在问题以及未来的发展趋势。     

电子陶瓷和器件的低温共烧技术

较系统地介绍了电子器件用低温共烧陶瓷(low temperature cofired ceramics,LTCCs)材料,探讨了其工艺中的若干问题。电子器件用低温共烧陶瓷材料包括:玻璃/陶瓷复合材料、结晶化玻璃、晶化玻璃/陶瓷复合材料以及液相烧结陶瓷,其中典型的和最为常用的LTCCs为玻璃/陶瓷(特别是氧化铝)复合材料。正在研究的一些陶瓷介质材料中,Bi基介质材料引起了人们的关注。玻璃/陶瓷复合材料的制备工艺中,应当着重关注和加深了解玻璃的流动性和结晶性、玻璃的起泡、玻璃和陶瓷颗粒间的反应、共烧材料的匹配等问题,从优选材料配方和优化工艺着手,从而获得优质可靠的材质和器件。     

专利信息

一种低温共烧的玻璃陶瓷组合材料，光滑砖石表面防滑增强剂及其制备方法，陶瓷薄板的压制设备及压制方法，一种陶釉料及陶釉的烧制方法，透光装饰陶瓷片     

多层发射药的燃烧特性

利用已建立的圆环状多层发射药燃烧模型得到多层发射药的理论燃烧猛度Γ-Ψ曲线,并通过密闭爆发器实验测试了不同结构的多层发射药的静态燃烧性能,讨论了结构对多层发射药燃烧渐增性的影响。结果表明,火药燃去量处于0.2~0.8时,实验L-B曲线与理论Γ-Ψ曲线之间有着相同的变化趋势;过大(或过小)的内外层燃速比K和缓燃层厚度比X均对多层发射药的燃烧渐增性不利,只有在合理的范围里选择,多层发射药的燃烧渐增性才会呈现增强的趋势;随着药片宽厚比W的增大,多层发射药表现出恒面燃烧的特征,燃烧渐增性变佳。     

Multilayer thick-film technology as applied to design of microwave devices

Possibilities of the sandwich multilayer technology to design microwave integrated circuits are discussed. Original designs of various passive microwave devices realized as multilayer sandwich structures are presented. Experimental results confirmed a good potential of the sandwich technology to design high-performance multilayer microwave integrated circuits.     

In-plane lattice thermal conductivities of multilayer graphene films

The in-plane lattice thermal conductivities of a single layer and multilayer graphene films are investigated using nonequilibrium molecular dynamics simulations. It is found the thermal conductivity of a single layer graphene is higher than that of multilayer graphene. Increasing the bonding strength between neighboring layers will reduce the in-plane thermal conductivity for multilayer graphene films. The constraints from the neighboring layer play the role of impeding phonon transport along the in-plane direction in multilayer graphene films. This observation implies the thermal conductivity of a single layer graphene will be reduced in practical applications once it is bonded on a substrate.     

Sintering Arches for Cosintering Camber-Free SOFC Multilayers

We describe a series of experiments to learn how to produce flat LaSrMnO₃/YSZ/NiO-YSZ multilayer packages typically used for solid oxide fuel cells, in a single cosintering cycle, by applying a load during cosintering using sintering arches. We demonstrate that the key step is to apply the load gradually after the multilayer components are stronger and at their minimum viscosity of ∼6 GPa·s during sintering. Alumina sintering arches, which support an alumina loading plate above the multilayer laminate, were designed to yield slowly at the intermediate stage of cosintering and thus apply the loading plate to the multilayer package. The primary design features of sintering arches are the arch material viscosity behavior, and the arch width, thickness, and curvature.     

Fabrication and mechanical properties of single-wall carbon nanotubes and hyperbranched diazonium salt multilayers

Acidized single-wall carbon nanotubes (SWNTs) were fabricated into multilayers with a hyperbranched azobenzene-containing polymeric diazonium salt (PDAS) using the layer-by-layer adsorption technique. The fabrication process, multilayer thickness variation, multilayer surface morphology and the interaction between SWNTs and PDAS were monitored by UV-Vis absorption spectroscopy, optical ellipsometry, Atomic Force Microscopy, Scanning Electron Microscopy and Raman spectroscopy. Moreover, the nanomechanical properties of the multilayer films were measured by nanoindentation. All results show that SWNTs and PDAS can be fabricated into multilayers based on the cooperation of electrostatic absorption and chemical cross-linkage between SWNTs and PDAS. Further, this cooperation endows the SWNT/PDAS multilayer films with outstanding nanomechanical properties. The hardness and modulus are about 2.0GPa and 10.0GPa, respectively. Finally, the SWNT/PDAS multilayer film can be peeled off to be a free-standing film.     

Investigation of the neutron reflectivity of multilayer carbon structures

The principal possibility of creation of a new type of multilayer neutron structures using hydrogenated carbon films is described. The structures are based on a carbon matrix filled with a spatially periodic concentration of hydrogen. The reflection coefficient of the multilayer carbon structures is investigated both theoretically and experimentally. It was shown that the difference in the hydrogen concentration in the carbon layers is the main reason for the neutron reflectivity of multilayer carbon structures.     

Ag靶弧流对TiN/Ag多层膜结构和性能的影响

采用电弧离子镀技术,通过改变Ag电弧靶的弧流在医用不锈钢基底表面制备TiN/Ag多层膜,分析多层膜的微观结构,测试多层膜的厚度、结合强度和硬度,通过摩擦磨损实验测定多层膜的摩擦系数,研究了不同Ag靶弧流对多层膜结构和性能的影响规律。实验结果表明,在不同Ag靶弧流下,TiN/Ag多层膜有TiN(111)晶面和Ag(111)晶面择优生长。Ag靶弧流在一定程度上影响着多层膜中Ag的结晶度,当弧流为50 A时,Ag的结晶度达到最佳,此时多层膜的结合力最大,为45.33 N;多层膜的硬度达到最小值1 189.4 HV;多层膜的摩擦系数最小,为0.242。Ag靶弧流影响Ag层的结晶度,并且对多层膜的结合强度、硬度和摩擦系数具有明显影响。     

红外反射保温膜研究

采用两种或两种以上具有不同折光指数的透明热塑性树脂交替组合,形成总层数为121层匀平行的交替层总厚度达0.015～0.050mm的多层反射干涉膜。结果发现,当薄膜厚度一定时,其对1000～1400nm的红外线有明显的阻膈效果,从而可提高薄膜的保温效果。     

The effect of annealing on mechanical and tribological properties of diamond-like carbon multilayer films

The diamond-like carbon (DLC) multilayer films have been deposited by plasma CVD deposition onSi wafer substrate. The deposited films have then been post-annealed in vacuum at 250 °C for 2 h. Changes in internal stress, hardness, critical load, friction coefficient and wear have been investigated toassess the influence of annealing on mechanical and tribological properties of DLC multilayer films. At the same time, DLC single layerfilms are also deposited and annealed in the same method for a comparison.The results show that there is 28–33% decrease in internal stress and 10–13% decrease in hardness of theDLC single layer films after the anneal treatment. However, for the DLC multilayer films, there is 41–43% decreasein internal stress and less than 2% decrease in hardness. In addition, the annealed DLC multilayer filmhas the same friction and wear properties as that un-annealed film. This result indicates that the anneal treatment isan effective method for the DLC multilayer films to reduce the internal stress and to increase the critical load.The by-effect of the annealing, decrease of hardness and wear resistance of the multilayer film, can be restrictedby the multilayer structure.     

电化学法制备多层膜的研究进展

介绍了电化学方法制备多层膜的研究进展,阐述了单槽法和双槽法制备多层膜的原理、优缺点及适用范围;简述了制备多层膜的电化学方法,为制备多层膜提供了新的思路;同时介绍了多层膜的表征手段并展望了其发展前景.