汽车用功率MOSFET及其封装

现代功率MOSFET被日益广泛地应用在汽车上,是最具发展前景的功率器件之一。文章在概述不同种类功率MOSFET特点的基础上,具体分析了当前主要的汽车用功率MOSFET的分类、结构、性能及其封装形式与改进,并给出这一领域的现状及发展趋势。     

电子设备的故障及其规律分析

电子设备故障发生的频率,与使用时间的关系,从宏观来看,具有一定的统计规律性,其故障规律是一个非线性曲线.本文分析了电子设备的故障及其规律.     

军用电子产品无铅焊接工艺

阐述了使用无铅钎料存在的主要问题,包括高温带来的问题、立碑、焊点剥离、晶须以及铅污染问题等,对其中的"铅污染"问题进行了着重说明;结合军用电子产品的特殊性,明确了军品无铅化过程中所应当重视的可靠性试验;针对无铅化的特殊性问题,提出了应当增添的相应检测手段.     

Electronic Structure And Magnetism of Novel Diluted Magnetic Semiconductors CdGeP 2 : Mn and ZnGeP 2 : Mn

Chalcopyrite II-IV-V 2 semiconductors CdGeP 2 : Mn and ZnGeP 2 : Mn are new types of diluted magnetic semiconductors (DMSs). Since their ferromagnetic Curie temperatures are much higher than room temperature, these DMSs are good candidates for materials to be used in spintronics devices. Their electronic and magnetic structures have been investigated using the first-principles calculations based on the Korringa-Kohn-Rostoker coherent-potential-approximation and local-density-approximation (KKR-CPA-LDA) methods. When Cd or Zn atoms are substituted by Mn atoms, the ground state magnetic structure is spinglass-like. On the other hand, if Mn atoms substitute Ge atoms, the system becomes ferromagnetic through the double-exchange mechanism. However, the calculation of the formation energies shows that this system is not energetically favorable. Instead, the system with vacancies (Cd, Vc, Mn)GeP 2 or a non-stoichiometric (Cd, Ge, Mn)GeP 2 are also ferromagnetic and, moreover, energetically stable. We conclude that either of these variants possess a ferromagnetic phase of the kind CdGeP 2 : Mn. Similar conclusions are obtained for ZnGeP 2 : Mn.     

电子技术综合实验室开放管理的实践与探索

电子技术综合实验室实行开放管理是高等院校电子信息类专业教学改革和应用型人才培养的需要,也是学生创新能力培养的有效保障.文中总结了电子技术综合实验室开放管理的一些方法和措施,以及有待进一步完善的地方,与同仁交流和探讨.     

Structural and Electrical Characterization of ZnO Films Grown by Spray Pyrolysis and Their Application in Thin‐Film Transistors

The role of the substrate temperature on the structural, optical, and electronic properties of ZnO thin films deposited by spray pyrolysis using a zinc acetate precursor solution is reported. Analysis of the precursor compound using thermogravimentry and differential scanning calorimetry indicates complete decomposition of the precursor at around 350 °C. Film characterization using Fourier Transform Infrared Spectroscopy (FTIR), photoluminescence spectroscopy (PL), and ultraviolet–visible (UV–Vis) optical transmission spectroscopy suggests the onset of ZnO growth at temperatures as low as 100 °C as well as the transformation to a polycrystalline phase at deposition temperatures >200 °C. Atomic force microscopy (AFM) and X‐ray diffraction (XRD) reveal that as‐deposited films exhibit low surface roughness (rms ≈ 2.9 nm at 500 °C) and a crystal size that is monotonously increasing from 8 to 32 nm for deposition temperatures in the range of 200–500 °C. The latter appears to have a direct impact on the field‐effect electron mobility, which is found to increase with increasing ZnO crystal size. The maximum mobility and current on/off ratio is obtained from thin‐film transistors fabricated using ZnO films deposited at >400 °C yielding values on the order of 25 cm² V^?1s^?1 and 10⁶, respectively.     

印刷电子用导电性油墨材料的开发

概述了印刷电子用纳米胶,电极/线路用和接合用金属纳米油墨和无须烧结的Ag纳米粒子技术的开发和应用。     

工艺控制保证电子装配产品的质量与可靠性

电子装配的过程,直接关系到电子产品最终的质量与可靠性.本文就电子装配过程的工艺控制,阐述怎样通过工艺控制保证电子产品的质量与可靠性.     

An experimental method for evaluating the heat transfer coefficient of liquid-cooled short pin fins using infrared thermography

The aim of this research is to evaluate the convective heat transfer coefficient of liquid cooled short pin fins by means of the infrared thermography. An experimental apparatus was set-up to analyze single, in-line and staggered array configurations of short pin fins. In this work the attention is focused on single pins having different shapes: circular, square, triangular and rhomboidal. The infrared thermography is used to indirectly measure the lateral pin temperature by observing the upper surface temperature of radially heated pins; these are placed in a test section chamber equipped with a Zinc Selenide infrared window. Flow visualizations by means of ink tracers are also carried out to relate the thermal behavior with the flow field. Regressions by the Zukauskas correlation were performed for each shape and new coefficients were carried out; a comparison among the different pin geometries underlines a better thermal exchange for the triangular and rhomboidal pins.     

Why use PEMs in military equipment: users'' response

Since the early 1980s, with significant improvement in plastic packaging of microcircuits, accelerated environmental testing has indicated continuous reliability improvements. These data have been generated by independent researchers, Universities, users and suppliers. The question which still remains concerns their use in high reliability applications for extended periods in harsh environments. Such applications would be in the military, automotive, and commercial airline markets. This report is the result of responses to a survey directed at military equipment developers. Its goal was to determine advantages and disadvantages in the use of commercial plastic encapsulated microcircuits (PEMs) versus the use of MIL approved microcircuits as received by the equipment manufacturer. Responses, however, impacted all three markets, not only military.