利用Gerber文件提高电子组装生产效率和质量

SMT生产线中的大多数加工设备均为数控设备。它们编程所需要的大多数特征数据均可从CAD设计系统中得到。如何在CAD设计系统和SMT自动化加工设备之间建立有机的联系和共享，正是我们所要解决的问题。本文介绍了从Gerber文件中导出X、Y坐标数据的方法，同时还介绍了如何从Gerber文件中导出DXF文件，最后文章指出利用Gerber文件可有效提升电子组装生产的效率和质量。     

碳纳米管和石墨烯在柔性电子器件中的应用

碳纳米管和石墨烯等新型碳纳米材料具有优异的电学、光学和力学特性,在柔性电子器件领域具有广阔的应用前景。从碳纳米材料的制备和器件的构建角度出发,本文介绍了基于碳纳米管和石墨烯的薄膜晶体管器件的最新研究进展。我们将已有碳基薄膜晶体管器件的构建方法分为固相法、液相法和气相法三类,重点讨论和比较了不同方法的技术特点和发展潜力,指出了碳纳米管和石墨烯材料在柔性电子器件领域中可能的实际应用前景和趋势展望。     

回流焊工艺中常见缺陷及其防止措施

元器件的微型化和产品的多功能化,驱动了产品安装设计的高密度化和立体化.其特点是焊点越来越密集;焊点尺寸越来越微小;间距越来越细.焊接缺陷是影响电子产品质量的主要因素,针对回流焊接工艺中常见的几种缺陷进行分析,并给出相应的解决措施.     

中国汽车电子市场现状与展望

本文对中国汽车与市场发展概况、中国汽车电子产业与市场发展概况、中国汽车电子市场竞争格局,以及中国汽车产业链进行了分析,并由此对中国汽车电子市场未来的发展进行了预测。     

Comparison of transient and static test methods for chip-to-sink thermal interface characterization

Accurate thermal interface characterization is essential for high flux microelectronic package design. However, it is increasingly difficult as interfacial bond lines are thinned and thermal interface materials (TIM) evolve to more complex formulations with better performance. This paper compares a static versus transient characterization method targeted at the chip-to-package interface in a test fixture that closely resembles a packaged chip. The static method requires measurements over multiple bond line thicknesses while the transient method yields additional information about the package at the cost of greater numerical complexity, hardware requirements, sensitivity to noise and experimental uncertainty. Both are compared with existing techniques. We conclude that the static method is more generally-applicable while transient is well-suited to rapid characterization of the interface when the rest of the package is well-defined. While both methods are sensitive to the accuracy and resolution of temperature and bondline thickness measurements, the transient technique is additionally sensitive to the relative contribution of the TIM in the full junction-to-ambient thermal path. These points are illustrated through experimental results and compact numerical modeling.     

基于电子签章技术的电子合同平台设计与实现

随着互联网的普及和信息技术的发展,基于网上交易的电子商务模式已经逐渐取代传统的交易方式,对于网络交易双方来说,如何确认对方的身份真实可信,如何确认对方发来的电子合同真实性、可信性和不可抵赖性是一个首要解决的关键问题.本文基于电子签章技术的电子合同平台的设计与实现,平台实现了信息传输的保密、数据交换的完整性、发送信息的不可否认性、交易者身份的确定性,从而保证平台使用的安全性.     

Applying Heteroatom Substitution in Organic Photovoltaics

Poly(3‐alkylthiophene) (P3AT) has been a central focus of research on organic photovoltaics (OPVs) for well over a decade. Due to their controlled synthesis P3ATs have proven to be a vital model system for developing an understanding of the effects of polymer structure on optoelectronic properties and blend morphology in bulk heterojunction OPVs. Similar to their thiophene counterparts, selenophene and tellurophene can be polymerized in a controlled manner. As single atom substitution results in significant differences in absorption, charge transport and self‐assembly these model systems provide a unique opportunity to probe fundamental structure‐property relationships. In this account, we provide an overview of our work on copolymers of thiophene and selenophene and examine how the optoelectronic and morphological behavior of these materials can be strategically adjusted through polymer design. We also highlight recent developments on poly(3‐alkyltellurophene) and comment on its future in fundamental and applied studies.     

The Resist Technique—A Chemical Contribution to Electronics

Besides its technical meaning, the word “electronics” signifies another industrial revolution. The driving force behind this development is the very rapid progress in the field of integrated semiconductor circuits. An ever-increasing number of structures of ever-decreasing size must be accommodated on the same surface of the semiconductor crystal. This trend towards miniaturization embraces not only the integrated circuit but also its mounting panel, the printed circuit board; integrated circuits with 65 536 storage spaces, i.e. more than 100 000 individual functions, on a semiconductor die of less than 1 cm² are already standard today in industry. This micro-world, the potential of which can hardly be fully appreciated even today, has a direct appeal to all those of scientific inclination. However, the role of chemistry in the creation of this world becomes clear only on closer examination of the manufacturing processes: no mechanical tool is fine enough and no machine is sufficiently precise and rapid to work out complicated structures in the micron range with the required perfection. Chemistry first made possible the mass production of electronic components and consequently their widespread use today, and it is chemistry which will also play a decisive role in the future. Whether in the field of photoresists for the production of printed circuit boards with conductor widths of less than 100 μm, or in overcoming the 1 μm barrier in the manufacture of semiconductors using electron beam- and X-ray-resists, photochemistry, radiation chemistry, and polymer chemistry will have to develop new manufacturing processes and provide industrially utilizable materials.     

Charge transport at the protein–electrode interface in the emerging field of BioMolecular Electronics

The emerging field of BioMolecular Electronics aims to unveil the charge transport characteristics of biomolecules with two primary outcomes envisioned. The first is to use nature's efficient charge transport mechanisms as an inspiration to build the next generation of hybrid bioelectronic devices towards a more sustainable, biocompatible and efficient technology. The second is to understand this ubiquitous physicochemical process in life, exploited in many fundamental biological processes such as cell signalling, respiration, photosynthesis or enzymatic catalysis, leading us to a better understanding of disease mechanisms connected to charge diffusion. Extracting electrical signatures from a protein requires optimised methods for tethering the molecules to an electrode surface, where it is advantageous to have precise electrochemical control over the energy levels of the hybrid protein–electrode interface. Here, we review recent progress towards understanding the charge transport mechanisms through protein–electrode–protein junctions, which has led to the rapid development of the new BioMolecular Electronics field. The field has brought a new vision into the molecular electronics realm, wherein complex supramolecular structures such as proteins can efficiently transport charge over long distances when placed in a hybrid bioelectronic device. Such anomalous long-range charge transport mechanisms acutely depend on specific chemical modifications of the supramolecular protein structure and on the precisely engineered protein–electrode chemical interactions. Key areas to explore in more detail are parameters such as protein stiffness (dynamics) and intrinsic electrostatic charge and how these influence the transport pathways and mechanisms in such hybrid devices.     

世界电子垃圾回收处理动态

就世界各主要工业国家和地区有关废旧电子产品的立法状况,以及废旧电子产品的回收、处理再利用实施现状进行了综述.面对严峻现实,中国必须加快研制开发具有自主知识产权的废旧电子产品回收、处理工艺技术和设备的步伐.