Optimization of the dielectric layer for electrowetting on dielectric

In this work the minimum actuation voltage V_min for droplet actuation with electrowetting on dielectric (EWOD) is analyzed. At first, the theoretical background of drop transport with EWOD is shown. Then the impact of thin dielectric films deposited with atomic layer deposition (ALD) and super-hydrophobic layers on the minimum required actuation voltage for drop transport are presented. To this, contact angles are measured on both Al₂O₃ and fluorinated DLC each with a drop of water. For verify the hypothesis, the analytically calculated values for the minimum actuation voltage V_min are compared with numerical simulation results using COMSOL Multiphysics^®. The results show that the actuation voltage value from the simulation is lower than calculated analytically.     

Active cooling substrates for thermal management of microelectronics

Heat removal in printed wiring boards (PWB) is primarily accomplished through conduction. This work presents a microelectromechanical system (MEMS) device comprised of an active cooling substrate (ACS) designed and fabricated to add fluidic cooling functionality to the PWB. Thermal management is enhanced through the additional heat convection mode. Synthetic jet technology makes the compact, but easily integrated, MEMS cooling device possible. The fluid control unit, a synthetic jet, has been implemented in an epoxy-glass printed wiring board by multilayer lamination. An air reservoir is drilled through the core of printed wiring board. A flexible polymeric diaphragm and a low profile electromagnetic driver create an active pumping system to produce vibrating air jets downstream of microfluidic channels which transports heat generated by hot microelectronic components. Test heater chips have been directly die attached to the substrate. The integrated packaging system has been characterized mechanically, electrically, and thermally. Peak jet velocities of 14 m/s and average jet velocities of approximately 3 m/s have been achieved at actuator powers of 60 mW. This integrated active cooling substrate has the potential for broad applications in thermal management at the system packaging level.     

Controlled steam oxidation of AlInAs for microelectronics and optoelectronics applications

Thermal oxidation in water vapor of AlInAs layers lattice-matched to InP is reported. Vertical oxidation rate, analyzed vs temperature and duration, is compared to lateral oxidation. The activation energies for both lateral and vertical oxidation on the one hand and kinetics of vertical oxidation on the other hand have been investigated. The doping dependence on vertical oxidation rate is also examined. The resistivity and breakdown field of these oxide films have been found to be high enough for device applications, while the refractive index has been determined through ellipsometry. Some information about the microstructure of the native oxide are also reported.     

Formulation and characterization of anisotropic conductive adhesive paste for microelectronics packaging applications

There has been a steadily increasing interest in using electrically conductive adhesives as interconnecting materials in electronics manufacturing. In this paper, several anisotropic conductive adhesive (ACA) pastes were formulated, which consist of diglycidyl ether of bisphenol F or diglycidyl ether of bisphenol A as polymer matrix, imidazoles as curing agents, and different sizes of silver (Ag) powders or gold (Au)-coated polymer spheres as conductive particles. The effects of ACA resin and different curing agents, as well as different conductive particles, on flexible substrate of the flip-chip joint were studied. The results show that the size and type of different conductive particles have very limited influence on an ACA flip-chip joint. The ACA resin as well as the curing agent can affect the reliability of the joint. The same results can be applied for the failure analysis of ACA flip-chip technology.     

基于液滴润湿形态测定接触角的图像处理方法

接触角是表征液体与固体润湿程度的重要度量参数,焊料、焊剂、焊盘及阻焊层的接触角与电子制造焊接工艺密切相关。针对目前基于图像测量接触角的精度还不够高的现状,提出运用Young-Laplace方程的物理原理作为图像处理的方法,基于液滴润湿形态图像处理体积并捕获顶点坐标作为拟合参数,获得良好的接触角测量精度,显著减小了重力、液滴体积和光反射干扰对测量结果的影响。     

The microelectronics applications of differential scanning calorimetry for packaging and materials—Including solder pastes

DSC analyses provide key understandings of materials and can be integrated with processing requirements. The DSC should not be an integral part of the quality control program but it provides an “essential” means to assure the selection of materials to meet the complex requirements of today's high technology.     

Optimization of thermal interface materials for electronics cooling applications

Thermal interface materials (TIMs) are used in electronics cooling applications to decrease the thermal contact resistance between surfaces in contact. A methodology to determine the optimal volume fraction of filler particles in TIMs for minimizing the thermal contact resistance is presented. The method uses finite element analysis to solve the coupled thermo-mechanical problem. It is shown that there exists an optimal filler volume fraction which depends not only on the distribution of the filler particles in a TIM but also on the thickness of the TIM layer, the contact pressure and the shape and the size of the filler particles. A contact resistance alleviation factor is defined to quantify the effect of these parameters on the contact conductance with the use of TIMs. For the filler and matrix materials considered-platelet-shaped boron nitride filler particles in a silicone matrix-the maximum observed enhancement in contact conductance with the use of TIMs was by a factor of as much as nine.     

数据中心氟侧自然冷却技术节能分析

氟侧自然冷却系统利用室外自然冷却资源,可提高数据中心节能性.本文通过建立空调性能模型,结合典型数据中心和天气数据,对系统的节能潜力进行分析.在数据中心制冷要求下,采用适宜的氟泵节能技术可拓展机房空调系统节能技术的应用,延长制冷系统全年自然冷源利用时间,并针对不同使用区域进行应用.     

能量和功率在分析跨区域模态中的现象时的应用

这篇论文提出了一种基于能量的小信号方法,用以分析区域间的低频振荡。在对电力系统线性模型中能量关系分析的基础上,一个全面的分析系统振荡的方法框架被建立起来。这种方法可以使我们深入的了解区域间现象的性质,也可以和现代技术结合起来进行复杂电力系统的频谱分析。