低介电常数聚合物材料的研究进展

综述了低介电常数(low-k)材料研究的基本情况,以及可用于微电子领域的低介电常数聚合物材料,包括材料的化学结构和基本物理性质。并着重介绍了带有纳米孔的超低介电常数材料的研究进展。同时,对低介电常数材料的制备工艺也进行了简要的总结。     

基于纳米多孔性聚合物低介电常数材料的研究进展

综述了纳米多孔性聚合物基低介电常数材料研究工作的基本情况。着重介绍了以聚酰亚胺、聚硅氧烷和环氧树脂为基体的纳米多孔低介电常数材料的研究进展,并对研究前景做了展望。     

高介电常数、低介电损耗聚合物复合电介质材料研究进展

高介电常数聚合物电介质材料作为当今信息功能材料的研究热点,具有实际的应用价值和前景。综述了聚合物基复合电介质材料的分类及优缺点,以及从材料微观结构设计和填料界面修饰出发(如三元杂化或设计核壳和三明治结构),来获得高介电常数、低介电损耗聚合物复合电介质材料的研究状况和应用前景,以期对高介电、低损耗聚合物基电介质材料有一个更直观全面的了解,进一步拓展该类材料在电气和生物工程领域的研究和应用。     

新型电容器用高介电常数聚合物研究进展

高介电常数聚合物具有优异的介电性和柔韧性,可以制备高容量有机薄膜电容器等无源器件,近年来受到广泛关注.目前理论和实验研究的热点主要集中在聚合物/无机介电陶瓷、聚合物/导电颗粒复合材料和纯有机聚合物材料.综述了这3种聚合物的高介电机理及研究进展.采用物理、化学方法进行表面修饰改性,掺入导电颗粒及设计具有高度芳环结构聚合物等措施,均可有效提高介电常数、减小损耗.     

高介电常数聚合物基复合材料研究进展

本文概述了目前高介电聚合物基复合材料的主要问题,论述了铁电陶瓷、导电颗粒(金属粒子、石墨、碳纳米管)改性高介电复合材料的国内外研究进展;重点介绍了酞菁铜、聚苯胺改性全有机高介电复合材料,探讨了存在的主要问题,并指出提高介电常数、储能密度,减小介电损耗,降低制备成本是未来发展的方向.     

低介电常数微波介质陶瓷研究进展

综述了国内外低介电常数微波介质陶瓷近10年来的研究进展,总结了低介电常数微波介质陶瓷的晶体结构、成分体系和烧结工艺等相互之间的制约关系,以及对介电性能影响的规律;归纳了研究中存在的问题,并对其它的低介电常数微波介质陶瓷也进行了简要介绍.最后展望了低介电常数微波介质陶瓷今后的发展方向.     

高介电常数聚合物基复合材料的研究进展

具有良好加工性能和机械性能的高介电常数聚合物基复合材料正受到世界的极大关注,其在电气工程、微电子和生物工程领域有着广阔的应用前景.复合材料的介电性能主要由功能体的种类和组合形式所决定,因此高介电常数聚合物基复合材料的发展主要表现为功能体的发展.从功能体的发展出发,综述了高介电常数聚合物基复合材料近期的研究进展,并指出了其发展方向.     

低介电常数微波介质陶瓷研究进展

随着微波通信技术向毫米波段延伸,低介电常数微波介质陶瓷的开发成为介质材料的研究热点。概述了Al2O3系、硅酸盐系、AAl2O4系(A=Zn、Mg)、钨酸盐系、磷酸盐系及石榴石结构化合物体系等低介电常数微波陶瓷材料体系的研究进展,并指出了低介电常数微波介质陶瓷目前存在的问题及发展趋势。     

低介电聚合物材料的研究进展

低介电聚合物材料因具有低介电常数、低介电损耗、耐热性力学性能良好等特点而被广泛应用于电子器件行业,随着5G通讯技术的飞速发展,传统的低介电聚合物材料制备方法已经面临淘汰。综述了近几年国内外低介电材料的研究,从基本理论出发列举了几种当下降低介电常数的主要方法：引入低极化基团、引入大体积分子或基团、引入多孔结构以及其它多种方法,并对低介电材料领域进行了展望和总结。     

低介电常数改性聚酰亚胺材料的研究进展

聚酰亚胺(PI)广泛应用于电子集成电路的绝缘材料领域。随着电子通信行业的不断更新换代,信号传输频率逐渐往高频发展(例如5G通讯),为了满足信号传输速度快、介电损耗低的要求,需要不断地降低印刷线路板(PCB)绝缘材料的介电常数。常规聚酰亚胺介电常数偏高,不适合直接用于PCB的绝缘材料,为满足未来5G高频通信要求,必须对其进行改性,因此本文综述了低介电常数聚酰亚胺改性的研究进展,并对其进行了展望。     

POSS基低介电常数多孔薄膜的制备与性能研究

通过4，4’-二（4-烯丙氧基苯甲酸）苯酯与POSS分子的硅氢化反应，合成了POSS交联聚合物。用FTIR、XRD对聚合物结构进行了表征，利用椭偏仪测量了薄膜的折射率和介电常数。通过改变单体与POSS投料摩尔比，可制备出k＜2.5的低介电常数薄膜。     

POSS基有机-无机杂化高分子的制备及低介电性能

利用硅氢加成反应技术，以多面低聚倍半硅氧烷T8H8和二（对烯丙氧基苯甲酸）丁二醇酯为单体合成了有机．无机杂化交联聚合物。用FTIR和^29Si NMR等对材料进行了结构表征，结果表明，在聚合物中两种单体以化学键相连，无机与有机相均匀分散，T8H8分子中平均有6.3个Si-H键与C=C双键发生了加成反应，得到了三维网络聚合物。TGA分析结果表明，聚合物具有较高的热稳定性，热分解温度为376℃。Ellipsometer测试结果表明，聚合物薄膜具有较低的介电常数，k值为2．4。薄膜表面经三甲基氯硅烷疏水处理后，k值减小为2．2。     

高介电陶瓷材料在油品介电精制方法中的应用

目前对于介电材料的研究与应用一般集中于电子产品及其相关领域，高介电陶瓷材料应用于油品精制领域还是一个新的尝试。首先简要介绍了介电力学精制工艺装置，并重点讨论了介电陶瓷在其中的应用及基本原理，最后选用几种不同介电常数的介电陶瓷材料在装置中进行了实验，实验证明，高介电陶瓷材料对油品有较好的精制效果，并且对于所选用的几种介电材料而言随着介电常数的增加精制效果也提高。     

Effect of oxygen plasma treatment on low dielectric constant carbon-doped silicon oxide thin films

Low dielectric constant (low k) carbon-doped silicon oxide (CDO) films are obtained by plasma-enhanced chemical vapor deposition. The k value of the as-deposited CDO film is less than 2.9. However, the k value may be changed during the integration process. In integration process, photoresist removal is commonly implemented with oxygen plasma ashing or by wet chemical stripping. In this work, the impact of oxygen plasma treatment has been investigated on the quality of the low-k CDO films. Different plasma treatment conditions, including variable pressure, r.f. power, and treatment time were employed. A variety of techniques, including X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, time-of-flight secondary ion mass spectrometry (TOF-SIMS), atomic force microscopy (AFM), and scanning electron microscope (SEM) were used to analyze the effect of the oxygen plasma post-treatment on the low-k CDO films. The result indicates that oxygen plasma will damage the CDO film by removing the entire carbon content in the upper part of the film with increasing treatment time, which results in an increase in the k value and film thickness loss. Our result also confirms that with low r.f. power and low pressure, the damage will be less.     

紫外辐照对超低介电常数SiCOH薄膜组成与机械性能的影响

采用紫外光辐照超低介电常数多孔SiCOH薄膜,研究不同照射时间对薄膜结构和性能的影响。采用动态纳米压入技术测量薄膜的力学性能,发现随照射时间增加,薄膜的模量（Er）和硬度（H）不断提高。当辐照时间增至6h时,薄膜力学强度分别达到Er约7.4GPa,H约1.0GPa。傅里叶变换红外光谱（FT-IR）、X射线光电子能谱（XPS）分析表明紫外辐照处理能够使薄膜样品中发生键的断裂与重新结合,从而改变了薄膜骨架的交联密度和刚性,进而提高力学性能。但介电性能并未受到明显影响,紫外辐照6h后,k值仅从2.0增至2.2。     

Ultra low dielectric constant polysilsesquioxane films using T8(Me4NO)8 as porogen

A class of ultra low dielectric constant polymethylsilsesquioxane (PMSQ) films with T₈(Me₄NO)₈ polyhedral oligomeric silsesquioxanes (T₈ POSS) as double-effective porogen was studied. Through the Me₄NO⁻ groups of T₈ POSS attacking the Si-O-Si chains of PMSQ, the POSS will be connected to the PMSQ crosslink system. POSS has the cage structure, which acted as the closed pores (≤ 1.5 nm). On the other hand, the Me₄NO⁻ groups served as the sacrificial template. When they decomposed after annealing, the open pores were then left in the films. The introduction of T₈ POSS can greatly decrease the dielectric constant of PMSQ, and effectively improve its mechanical strength owing to T₈(Me₄NO)₈ interconnected with PMSQ. These continuous and smooth films were prepared by spin-coating with thickness in the range of 60-200 nm. The dielectric constant of the films could be controlled by adjusting the proportion of porogen. These films showed good mechanical strength and ultra low dielectric constant. In particular, a POSS/PMSQ film with ultra low dielectric constant of 1.6 and modulus of 7 GPa had been prepared on silicon wafer by spin-coating.     

Prediction of liquefied natural gas (LNG) densities from new experimental dielectric constant data

A concentric cylinder capacitor has been used to measure the orthobaric liquid dielectric constants of multicomponent mixtures of the major components of liquefied natural gas (LNG) to an accuracy of approximately ± 0.05% at temperatures from 110 to 130 K. These mixtures ranged from a ternary mixture containing nitrogen, methane, and normal butane to four to eight component methane rich (74 to 90 mol %) mixtures containing up to 5 mol % of nitrogen, 16 mol % of ethane, 7 mol % of propane, 5 mol % of the butanes, and 0.44 mol % of the pentanes. Some of these mixtures were prepared to simulate commercial LNG compositions. Experimental densities previously reported for these mixtures have been combined with the mixture dielectric constant data to calculate values of the Clausius-Mossotti (CM) function and the excess CM function. Pure component experimental CM functions for LNG components except for propane and isobutane have been combined with the mixture data in the development of a simple calculational technique for the prediction of LNG densities to an uncertainty of approximately ± 0.15% based on a knowledge of the composition and dielectric constant of the liquid mixtures. In fitting the data, pseudo values of the CM function are derived for the slightly polar components, propane and isobutane, while constraining the mixture excess CM function to be zero.     

Thermally stimulated discharge current (TSDC) and dielectric constant of semiconducting glasses

In this paper the results of thermally stimulated discharge current (TSDC) and dielectric constant for 40PbO-60Bi₂O₃ glass thermoelectrets are presented. Measurements of TSDC and dielectric constant, ǵe, have been carried out in the temperature range 30–300°C. The thermoelectrets were prepared at different polarizing fields. The various observed peaks in the thermograms are discussed on the basis of space charge polarization. The trap energy is evaluated from the Garlick-Gibson plot of initial rise method. Similarly other parameters such as relaxation time, charge release etc are evaluated.     

高导热率及低介电常数的AlN/PI纳米复合薄膜研究

通过将纳米氮化铝加入到原位聚合而成的聚酰亚胺中以提高纳米复合薄膜的导热系数.采用KH550偶联剂对氮化铝粒子表面进行物化处理,以提高有机-无机两相界面的结合力.采用SEM、TGA等对材料的微观结构、热性能等进行了研究.结果显示无机粒子在纳米复合薄膜中分散均匀,并在保持较低的介电性能同时提高了复合材料的热稳定性和导热性能.这样的材料在电子封装材料和印刷线路板中具有很大的应用前景.     

Thermally driven sign switch of static dielectric constant of VO2 thin film

Smart multifunctional materials exhibiting phase transition and tunable optical and/electrical properties provide a new direction towards engineering switchable devices. Specifically, the reversible, tunable and sign switch dielectric constants via external temperature stimuli observed in vanadium dioxide (VO₂) make it a candidate of choice for tunable and switchable technologies devices. Here we report new aspect of the metal-insulator transition (MIT) through the sign switch of the static dielectric constant ε_S of pure VO₂. As it is shown, the static dielectric constant showed an abrupt change from positive at T < 70 °C to negative at T > 70 °C. ε_S > 0 confirms the insulating phase where charges are localized while ε_S < 0 confirms the metallic phase of VO₂ where charges are delocalized. We report for the first time the tunability of the dielectric constant from a negative sign for the static dielectric constant of VO₂ thin film rarely found in real physical systems. We also demonstrate the tunability and switchability of the real and imaginary part of the dielectric constant (ε) via external temperature stimuli. More specifically, the real (ε) and Imaginary (ε) showed an abrupt thermal hysteresis which clearly confirms the phase transition.