电子元件、组件

」_,N6O 02010751多层圆形组件半解析热分析方法的研究/史彭,陈雅妮,王占民(西安建筑私限大学)11电子学报一2001,29(8)一1121一1122文中研究上表面含热源的多层圆形组件半解析的热分析计算方法,用计算机求解其数值解来计算组件上表面温度分布.该计算方法可以用于集成电路、混合电路和微组装件的热设计工作.图3参5(金)MLC)瓷料系统中,其介电性能的变化.结果表明,加入适量的玻璃能显著地降低烧结温度,系统的介电系数随温度变化平坦,改善了系统的热稳定性.然而,过量的玻璃将会引起瓷料系统损耗的增加,绝缘电阻的减小.玻璃成分含量不同的瓷料…     

行波管阴极和热子组件的热特性的数值模拟和实验研究

阴极热子组件作为星载行波管的核心部件,要求它具备稳定可靠、寿命长久、低功耗的特点。该文利用数值模拟和热测实验对某星载行波管阴极热子组件结构开展了研究,提出一种接触热阻估算方法,模拟了阴极热子组件结构热特性,设计并完成了阴极热子组件结构热测实验,首次获取了结构在一系列热子加热功率下由内到外的温度实测数据。进一步,通过修正阴极热子组件结构热模拟边界及激励,迭代得到接触热阻值,获取了一种高可靠的阴极热子组件结构热模型,实验表明,该热模型阴极温度计算精度在5%以内,结构最大温度计算误差不超过72 C。     

X波段T/R组件功率放大器芯片的热设计

针对X波段T/R组件中的功率放大器芯片,建立芯片热模型,给出了获取器件热阻的公式和方法,并对功放芯片的等效热路进行了分析计算.文中给出了常用材料的热导率,对不同壳底材料,求出了在确保功放可靠工作下的系统最大热沉温度,从而为组件设计师优化组件成本提供了依据.最后提出了提高功率芯片可靠性的建议.     

行波管电子枪组件的热及形变分析

使用Ansys软件,对行波管的电子枪阴极组件进行了热分析和形变分析.计算了阴极在真空条件下,加载热辐射与热传导两种边界条件时到达温度稳定所需要的热启动时间,以及得到了阴极组件在温度稳定后的热形变大小和等效应力的分布,并将这些结果应用在微波管设计套装MTSS中计算了形变对阴极发射所产生的影响,对实际的阴极组件设计提供理论...     

基于ANSYS的挠性基板叠装互联组件热分析

长期使用环境中交变温度载荷引起的结构热疲劳会显著影响挠性基板叠装互联组件的结构强度和使用寿命.以挠性基板叠装互联组件为研究对象,基于ANSYS软件参数化建模方法建立了挠性基板叠装互联组件三维有限元模型,针对互联组件六种内部芯片布局方案进行了互联结构热特性分析并进行对比.然后基于正交试验方法分析了多种影响因素对互联组件热...     

一种基于ATCA架构的高可用性系统设计与实现

本文提出一种灵活的、可动态装载、基于组件模块化的对称式主/主型高可用性热备份技术的系统软件框架,大大地扩展了高可用性计算能力,使得在ATCA高级电信计算平台上的所有组件能够协同、高效地保证系统服务的高可用性。     

X 波段带状电子注速调管电子枪组件热分析

使用ANSYS 仿真和热膨胀实验的方法进行了X 波段带状电子注速调管电子枪组件热分析,计算了电子枪组件的热分布和热形变,在动态实验台上完成聚束极阴极组件的热膨胀实验,将仿真和实验相验证得到了满足工程设计要求的重要热力学数据,为X 波段带状电子注速调管电子枪结构的精确设计、优化和实际制管提供了依据。     

复杂外热流条件下红外探测器组件热设计

为实现在复杂外热流条件下对CO2探测仪红外探测器组件温度的有效控制,对其进行了详细的热设计。对红外探测器周围外热流进行分析,确定了其散热面位置。基于红外探测器所处空间热环境以及自身高功耗、低热控指标的特点,提出热设计方案。对红外探测器组件有限元模型进行了热分析计算,得到各个转角姿态下的红外探测器组件的温度范围为-31.8~-26.9℃,计算结果满足设计要求。通过CO2探测仪热平衡试验对热设计进行了验证,试验中红外探测器组件的温度范围为-32.6~-30.1℃,试验结果与计算结果基本一致,满足热控指标要求,说明热设计方案在复杂外热流条件下合理可行,具有较好的适应性。     

某空间反射镜支撑装调技术

为了降低反射镜支撑装调对反射镜面形精度的影响,文中针对某空间相机的反射镜组件,设计了一种带有柔性环节的反射镜支撑方式,制定了反射镜组件的装调方法及路线。通过计算给出了反射镜粘结胶层厚度、粘结区域、柔性铰链等参数,并对反射镜组件进行了重力和5 ℃温变共同作用下的有限元分析。最后,根据装调工艺对反射镜组件进行粘胶、固化处理,并通过反射镜组件力学试验和热真空试验对装调方法进行验证。试验结果表明:力学和热真空环境下反射镜粘胶没有破坏,该反射镜组件的面形精度优于1/50 。验证了反射镜支撑方案以及装调方法的有效性。     

彩色CRT荫罩热变形分析与束着屏漂移预测

阴极射线管中荧光屏上电子束着屏漂移是由荫框架组件热变形引起的,从而使色纯变坏。本文使用有限元法（ＦＥＭ）分析了荫罩框架组件的热变形,预测了束着屏漂移。为了真实地分析,计算了表面热传导率和表面弹性系数,并将荫罩模拟成一个无孔的薄板。模拟了ＣＲＴ内所有的零件并考虑了每个零件的辐射效应。然后对荫罩框架组件瞬间的热弹性变形进行有限元分析,计算了束着屏偏移。４３ｃｍＣＲＴ的实验使有限元分析法有充足的根据。测量了ＣＲＴ内各个零件的温度和屏上着屏漂移,通过将测得的结果与有限元分析所得结果进行比较,对这些结果进行了讨论。通过研究我们知道这种分析方法可用来设计ＣＲＴ荫罩组件,将着屏漂移降到几微米级。     

混合封装电力电子集成模块内功率电路对驱动保护电路的热影响

混合封装电力电子集成模块(IPEM)是目前中功率范围内电力电子集成的主要方式。IGBT器件与控制和驱动电路高密度地封装在一起,IGBT的发热对驱动保护电路会产生非常不利的影响,我们针对这个问题进行了研究。利用三维有限元法建立了模块内的传热模型,对不同发热功率下IGBT的结温以及驱动保护电路PCB的最高温度进行了计算和分析。另外,对功率电路与驱动保护电路PCB之间存在空气隙以及模块完全被密封后模块内的传热问题也进行了实验研究。     

Transient thermal analysis of multilayered structures using Green's functions

This paper presents an approach to the analysis of transient thermal states in electronic circuits using an analytical solution of the heat equation. Fully three-dimensional analytical time dependent solutions are determined for multilayered structures with the help of Green's functions (GFs). The GFs required for the solution are found using a Galerkin-based integral method. The entire solution method is illustrated in detail using a practical example, where the results of transient thermal simulations of a real hybrid power module are compared with infrared measurements.     

A hybrid optimization approach for chip placement of multi-chip module packaging

The aim of this article is to provide a systematic method to perform optimization design for chip placement of multi-chip module in electronic packaging. Based on the investigation of the structural and thermal characteristics of multi-chip module, the key performance indexes of multi-chip module that include the lowest internal temperature objective, thermal-transfer accuracy, chip placement are analyzed. A hybrid model is presented by using genetic algorithm and response surface methodology for optimization. Furthermore, some design processes for improving the performance are induced. Finally, an example is discussed to apply the method.     

Developing a Simplified Analytical Thermal Model of Multi-chip Power Module

The study of the thermal behavior of power modules has become a necessity regarding the known rapid development in modern power electronics, and the prediction of temperature variation has generally been performed using transient thermal equivalent circuits. In this paper we have developed a simplified analytical thermal model of a power hybrid module. This analytical method is used to evaluate the thermal parameters of a device. The model takes into account the thermal mutual influence between the different module chips based on the analytical method. The thermal interaction between components is dependent on the boundary condition, the dissipated power value in the different components and the number of operating chips constituting the module. This effect is modelled as a source energy and a thermal resistance simply computed tanks to reasonably low measurement applied on the module. The derived thermal models offer an excellent trade-off between accuracy, efficiency and CPU-cost.     

电子线路综合实验模块设计

该文提出了电路基础实验模块化的思想,给出7个基础实验模块的电路设计图,并给出了由这7个模块组成的两个小型综合实验电路系统的设计框图。在基础电路模块设计中充分考虑器件的通用性,提高实验的可行性,并与理论课的相关内容紧密结合,加深学生对基础理论的理解;在综合实验电路设计中既包含模拟电路的内容,又包含数字电路的内容,充分体现电路的综合性,并增加实验的趣味性,启发学生的创新意识,提高学生的综合电路设计能力。     

Evaluation of Thermal Resistance Matrix Method for an Embedded Power Electronic Module

Thermal characterization provides data on the thermal performance of electronic components under given cooling conditions. The most common thermal characterization parameter used to characterize the behavior of electronic components is the thermal resistance. In this work, experiments are conducted to obtain thermal characterization data for different chips in a multichip package. Using this data, it is shown that the assumption of a linear temperature rise with input power is valid within the expected range of operation of the electronic module. Secondly, the applicability of a resistance matrix superposition methodology to the packaging structure of an integrated power electronic module is evaluated. The temperatures and the associated uncertainties involved in using the resistance matrix superposition method are compared to those obtained directly by powering all chips. It is shown that for any arbitrary power losses from the chips, the resistance matrix superposition method can predict the temperatures of a multichip package with reasonable accuracy for temperature rise up to 50degC.     

Efficient calculation of transient temperature fields responding to fast changing heatsources over long duration in power electronic systems

A method is presented, which describes the evolution of the complete temperature field in electronic systems by multiplication of two low order matrices, one depending on position, the other one on time. The first matrix constitutes the model and is fitted with a linear and fast algorithm to measurement or simulation. A very fast and accurate calculation of the temperature evolution in multichip-modules (MCM) is achieved, which is beyond the practicability of finite element method (FEM)-analysis in case of high frequency power pulses over long time intervals. The problem of temperature response to arbitrarily fast heat-source changes is solved by an analytical result, which gives the steepness of the thermal impedance at time zero. The method is applied to a high frequency dc/dc-converter and a dc/ac-converter [integrated starter generator (ISG)] module both for automotive applications. A new methodology is presented for constructing thermal equivalent circuits for electrothermal simulation with a multitude of temperature dependent heat sources.     

Analysis of integrated circuits thermal dynamics with point heating time

The article presents an analysis of thermal dynamics in integrated circuits using a new method. The introduced variable that defines the dynamic state of an IC is point heating time (PHT). The authors examine the dynamic behaviour of the integrated circuit caused by the thermal activity of one and many functional modules on the multi-core chip. Various substrate materials were analysed and the PHT value was compared to the mean temperature of the integrated circuit and its time constant. The PHT value is also analysed as a variable dependent on the distance from the heat centre of the heating module. The analytical equation, which is a result of the analysis, can describe the PHT value versus distance for the whole chip surface. Further analysis helps verify the hypothesis using a massive multi-core integrated circuit. The result can be used to increase the thermal efficiency of multi-core integrated circuits by thermal-aware flow modification of the scheduling algorithm.     

基于ANSYS的电子组件有限元热模拟技术

随着电子组件集成化程度越来越高，单位何种内的热耗散程度越来越高，导致发热量和温度急剧上升，由于热驱动引起的机械，化学、电气等可靠性问题越来越严重，严重影响了产品的质量和可靠性，本文以大功率电子组件DC/DC电源变换器为例，提出了基于通用的大型有限元分析软件ANSYS进行热模拟分析方法，并利用实验结果对模拟结果进行了验证。     

Thermal reliability prediction and analysis for high-density electronic systems based on the Markov process

Thermal-mechanical fatigue is one of the main failure modes for electronic systems, particularly for high-density electronic systems with high-power components. Thermal reliability estimation and prediction have been an increasing concern for improving the safety and reliability of electronic systems. In this paper, we propose a stochastic process prediction model to estimate the thermal reliability of an electronic system based on Markov theory. We first divided the high-density electronic systems into four modules: the energy transformation and protection module, the electronic control module, the connection module, and the signal transmission and transformation module. By integrating failure and repair characteristics of the four modules, a stochastic model of thermal reliability analysis and prediction for a whole electronic system was built based on the Markov process. The feature parameters of thermal reliability evaluation, including thermal reliability, thermal failure probability, mean time between thermal faults, and thermal stable availability, were derived based on our comprehensive model. Finally, we applied the model to an indoor electronic system of DC frequency conversion conditioning. The thermal reliability was estimated and predicted using tested failure and debugging repair data. Effective methods for improving thermal reliability are presented and analyzed based on the comprehensive Markov model.