机载电子设备功放模块的热设计

电子设备工作过程中,温升过高是造成故障率增大的主要原因之一。对系统进行合理的热设计,必将大大提高电子设备或系统的可靠性。为此,对机载电子设备的热设计及其仿真进行了初步探讨。     

电子设备热仿真分析及软件应用

阐述了电子设备热分析重要性并简单介绍了常用热分析软件,利用 FLOTHERM软件对一电子设备进行热分析,在此基础上对该电子设备的热控制进行改进设计,通过数值仿真获得满足热控制要求的优化设计参数,以达到工程要求;并将这一模型用FLOTHERM软件进行热分析的结果与用Icepak软件计算结果进行对比,指出两种软件在进行电子设备热设计时的差异.     

临近空间大功率电子设备的热设计

大功率电子设备发热量大,直接工作在恶劣的空间热环境,其热设计十分复杂.针对临近空间热环境特点,结合大功率电子设备工作模式及热控要求,采用热隔离、热控涂层、低热阻途径、提高换热效率等方法对其进行热设计.在此基础上用Icepak软件进行了热仿真,给出了合理优化的设计方案.临近空间环境模拟试验验证了热设计的正确性,对临近空间电子设备的热设计有一定的指导和借鉴作用.     

基于Icepak的通信电子设备热设计及优化

本文结合通信电子设备工程实际,阐述了基于Icepak的通信电子设备热设计及优化的过程,探索了一种仿真计算与优化验证的热设计方法。文中通过初步计算选择合理的散热方式及确定散热布局,并详细介绍了利用Icepak软件对散热布局进行仿真计算的过程和散热器的参数化及优化设计过程。这种基于Icepak的热设计方法能明显提高设计效率,解决工程实际问题,对于通信电子设备的热设计具有参考意义。     

基于Flotherm的某机载设备电源模块散热设计

应用专业电子设备热仿真软件Flotherm辅助对某电子设备电源模块进行风冷系统设计,定量分析了模块在高温、常温下正常工作时所需的进风量范围,并仿真计算了模块在该进风量范围的风道阻力特性曲线。     

基于Flotherm的电子电路热仿真分析与研究

在阐述电子设备热仿真分析重要性的同时,简单介绍了电子设备传热类型,并对热分析软件的基本理论进行解析。介绍了热分析软件Flotherm的功能特点及应用范围,并以教学机器人PCB控制板为研究对象,用Flotherm软件对其电子电路进行热仿真分析,详细讲述了计算模型的建立、边界条件设置、网格划分、结果分析及优化处理等操作。通过仿真分析数据与实验结果比较,发现热仿真分析存在一定误差,分析研究误差存在的主要因素,提出通过优化操作的方法减小误差,达到较高的热分析精度,满足使用需求。     

一种机载电子设备的热设计仿真与试验研究

介绍一种机载电子设备机箱的热设计,使用IcePak软件对机箱内部空气流动情况进行仿真分析。分析结果表明:当风扇与模块之间的间距达到40 mm以上时,机箱内的流场分布趋于均匀。试验测试验证了仿真结果的正确性,该结论可以作为类似的电子设备机箱热设计的参考。     

开关电源热仿真模型研究

温度是影响开关电源电路可靠性的重要因素之一,因此,热设计是进行开关电源电路设计的重要环节.阐述了电子设备热分析的重要性,简单介绍了常用的热仿真软件;并根据实际电源电路,介绍如何用Flotherm软件对开关电源电路进行热仿真.     

某电子设备的热分析

热设计在电子设备结构设计中是十分重要的环节,对提高电子产品的运行稳定性具有重要的意义。通过Ice-pak软件对某电子设备进行热仿真分析,得到了发热器件的温度分布云图。在此基础上,通过改进方案,将器件最高温度控制在耐受温度以下。利用热仿真软件可以及时发现方案中所存在的问题,在提升设备品质性能的同时,缩短了设备的研发周期。     

高可靠电子设备可靠性仿真试验技术应用研究

可靠性仿真试验是一门近年来兴起并不断发展的新技术,是解决高可靠电子设备可靠性健壮设计的重要方法。对热仿真、振动仿真以及故障预计仿真等各种仿真技术进行了分析与整合,研究出适用于高可靠电子设备可靠性仿真评价的流程,从而可以利用可靠性仿真试验来有效地发现产品设计的薄弱环节,并对产品可靠性水平进行快速评价。     

电子系统的热仿真及热测试研究

通过对电子系统热控制技术的介绍,分析了电子系统的可靠性与热仿真之间的关系,阐述了热仿真的优点。详细介绍了热测试的方法和手段,突出了热测试在高热流密度热控技术中的作用,并以实际应用中的热仿真结果与热测试数据进行了比较,进一步说明了热仿真与热测试协同工作,相互验证的重要性。     

多发射极指分段结构功率SiGe HBT的热分析

提出了一种有效的方法—采用多发射极指分段结构来增强功率SiGe HBT的热稳定性。为了对分段结构进行精确的热分析,针对器件多层结构的特点,建立起适当的热模型,模型中充分考虑了各个部分的热阻。根据此热模型,使用有限元方法,对一个十指的分段结构功率SiGe HBT进行了热模拟。考虑到模拟的精确性及软件的功能限制,采用两步模拟法:衬底模拟和有源区模拟。通过模拟,得到了发射极指的三维温度分布。结果表明,分段结构功率HBT的最高结温和热阻都明显低于完整发射极指结构,新结构有效地提高了器件的热稳定性。     

热仿真在电子设备结构设计中的应用

应用热分析技术,能在产品的设计阶段获得其温度分布,从而优化设计,提高产品可靠性.介绍了用计算机进行辅助热分析的数值方法和热分析软件的特点.并用Icepak软件对某电子设备进行了热分析,并把仿真结果与实验值进行了比较,验证了方法的正确性.同时还对电子设备的散热进行了改进,并通过计算,获得了满足要求的优化设计参数.     

Validation of TSV thermo-mechanical simulation by stress measurement

Because of the large mismatch in coefficients of thermal expansion (CTE) between copper vias and the silicon substrate in through-silicon vias (TSVs), thermal stresses are induced. These stresses cause severe reliability issues, such as performance degradation of stress-sensitive devices, and interfacial delamination between TSVs and the silicon substrate. Finite element method (FEM) simulation is a useful tool for thermal stress analysis; however, developers and users are concerned about the range of accuracy of simulation models. Direct validation of the thermal simulation via stress measurement is extremely difficult. As non-destructive methods can measure the stresses only at the surface or several micrometers below, it is difficult to measure the internal stresses. Furthermore, any attempt to use an internal measurement location in the sample affects the stress situation. We propose a methodology to validate the simulation model with stress measurements using polarized Raman spectroscopy on cross-sections of TSV samples. The stress-free assumption at room temperature for simulation was compensated for using the measured residual stresses. An accurate comparison of stress data between experiment and simulation was achieved by considering the re-location of measurement points under thermal deformation. The agreement between simulation and experimental data for radial and axial thermal stresses validated the simulation model.The validated simulation model is useful for structural parametric analysis of TSV. The proposed methodology with stress measurement by polarized Raman spectroscopy and stress analysis by simulation can be used to study the radial and axial thermal stress of other devices.     

High resolution thermal simulation of electronic components

An efficient thermal management in electronic components is essential to minimize the influence of thermomechanically induced stress and thermal load. Frequently, thermal simulation tools are applied to reduce the number of experiments needed for thermal characterization of the semiconductor components. However, for using commercially available software packages, much effort is necessary for maintenance and for generating the thermal models. Moreover, the limitation of the node number does not allow a discretization sufficiently fine for more complex structures as in high lead count packages. In this paper, a new thermal simulation tool is presented, which allows one to create models in a very efficient way. The developed and implemented solver based on the alternating direction implicit method is efficiently processing the required high node number. Moreover, the developed thermal simulation tool is applied for the thermal characterization of a 176 lead quad flat pack (QFP-package) using a discretization with 320,000 nodes. Steady-state and transient thermal qualities of the package are investigated under boundary conditions as specified by the Joint Electronic Device Engineering Council (JEDEC). Further, results obtained by thermal simulation are compared with those established from experimental procedures. Conclusions of how this new tool can be used for thermal design optimization are derived.     

Electro-thermal and logi-thermal simulation of VLSI designs

Due to severe thermal problems of today's VLSI integrated circuits the need for reliable and quick thermal, electro-thermal and logi-thermal simulation tools is increasing, In this paper, we discuss the latest advances in the SISSI package (simulator for integrated structures by simultaneous iteration) which is a tool developed originally for analog VLSI design. The improvements include electro-thermal ac and transient simulation and the consideration of the thermal voltage of Si-Al contacts. Furthermore, we introduce a new module of SISSI, LOGITHERM, which is aimed at the self-consistent logic and thermal simulation of large digital VLSI designs. The features of our simulator package are highlighted by simulation examples that are compared in most cases with measurement results     

Finite element simulation of thermal fatigue in multilayer structures: thermal and mechanical approach

The large difference in thermal expansion between dissimilar materials present in any electronic package is the source of a major problem to be solved in order to achieve improved reliability. In this paper, simplified thermal and mechanical finite element models are presented for the analysis of thermal stress derived problems. The problems investigated here include, thermal stresses in adhesive backbonds in surface mounted structures and effects of thermal fatigue in soft solder interfaces in conventional power modules such as insulated gate bipolar transistors modules. Full multi-dimensional mechanical and thermal analysis is made by using the commercial engineering computer package . Validation of the thermal simulation is achieved by comparison between simulation and experimental test results, whereas a simple analytical model based upon the lap joint theory is used to verify the structural simulation.     

Flotherm软件在光纤测井高温电路热设计中的应用

根据基于PCB设计的实现高温电路的传统法,利用热仿真分析软件对光纤测井电路系统的耐高温性能进行了热设计。首先利用红外热像仪对光纤测井电路系统进行了红外扫描,确定电路系统的主要热源并得到温度场分布,然后根据红外测试所确定的热源,利用热仿真分析软件对光纤测井电路系统进行建模并解算,可得到一定温度下电路系统的热仿真温度场分布,通过对所得到的温度场分布进行分析,进而对电路系统的结构和低功耗设计进行改进,最终提高了整个电路系统的耐温性能。     

Signal Level Simulation Modeling for Antenna Array of Aperture Synthesis Radiometer Based on the Equivalent Complex Baseband Representations

This paper presents a signal-level simulation model for simulating the process that antenna array of Aperture Synthesis Radiometer (ASR) collecting thermal radiation and transforming thermal radiation signal into radio frequency (RF) signal. By using the equivalent complex baseband signals to represent the practical thermal radiation and RF signals, simulation efficiency is improved significantly. The statistic characteristics of simulation results are found to match the corresponding theoretical analysis well. Results of an imaging simulation experiment show that this model can be employed in ASR system-level simulator design.     

基于Icepak的功率芯片散热结构热阻计算

介绍了混合电路中功率芯片典型散热结构及其热阻的数学计算方法,以及运用Icepak热仿真软件对散热结构建模并对其热阻进行计算的过程.对计算结果进行了验证,并运用仿真软件建模求解的方式,得到各典型散热结构的热阻数据.