某混动轻卡电池托架结构的优化设计

采用有限元分析法,采用HYPERMESH进行前处理,采用OPTISTRUCT进行模态和强度分析,采用HYPERVIEW进行后处理.对原混动轻卡电池托架结构的强度进行计算分析,结果表明该托架结构的强度不足.针对这一问题,结合电池托架应力分布图,对托架应力集中的部分进行优化,进行下一轮强度计算,使得托架结构满足材料的屈服强...     

CAE技术在电视底座受力分析中的应用

首先,简述了平板电视整机底座的类型和受力特点;然后,简要地说明了应用CAE软件对底座支架进行有限元分析的基本过程和步骤;最后,例举了两个应用SolidWorks Simulation和ANSYS软件对电视底座进行有限元力学分析的实例,验证了Solidworks Simulation和ANSYS的有效性和可信性.     

一种如厕坐立辅助装置的结构设计

如厕坐立辅助装置旨在解决大量人群面临的如厕就座起身不便问题.本文采用SolidWorks三维软件对如厕辅助装置进行了结构设计和运动仿真,验证了结构设计的合理性和运动的可行性,并对结构进行了有限元分析,校核装置的强度和刚度.     

一种机载电子设备故障分析

当某机载电子设备进行振动试验时,进行第三个方向的振动时发生了故障。对其进行故障分析后,是由于安装托架和试验工装之间的紧固件未达到紧固要求。文章通过有限元分析对机载电子设备及其安装托架进行了分析,进一步验证了故障定位。最终排除故障因素后,机载电子设备顺利通过振动试验。     

机载设备的隔振系统设计

针对机载设备的隔振需求,对机载设备进行了振动分析和隔振设计。利用SolidWorks软件建立机载设备的三维模型,通过ANSYS有限元分析软件对机载设备进行了模态分析,得到系统的固有频率和振型。对机载设备进行了随机振动分析,得出机柜不同部位在激振频率范围内的加速度响应和应力响应。结合动力学仿真结果和隔振理论对机柜进行了隔振系统设计,对机载设备的隔振效果进行了试验验证。试验结果表明,隔振系统达到了较好的隔振效果。     

基于SolidWorks Simulation的压头热应变分析

利用SolidWorks Simulation有限元分析软件对邦定机压头结构进行热应变分析,得出压头工作面热变形规律,为压头结构设计和改进提供了重要依据。     

模拟并分析你的机器人零件——结构有限元分析功能

各位看官好啊,书接上文,在本期的SolidWorks系列文章中,我将向你展示一下SolidWorks的结构有限元分析功能。拿来演示的,是咱们上期画的机器人的车体,也就是那个塑料饭盒！     

针对复杂振动环境的光电托架改进设计及分析

光电托架是激光电视组合的重要支撑件,要求高刚性和高强度。现有的光电托架一阶频率较低,在低频阶段产生共振会影响激光电视组合的成像精度。对现有的托架进行了结构设计改进,将框架式托架优化为"L型"结构。通过有限元仿真,模态分析表明一阶频率从22.6 Hz提高到62.6 Hz,正弦振动仿真表明应力和变形情况均有很大程度的提高。该优化设计方式可以为相似结构优化设计提供参考。     

基于垂直驱动的压电振动送料器结构设计分析与试验研究

振动送料器是自动加工和装配系统中的一种供料装置,由于其整列定向性能优良,供料效率高,通用性好,因而广泛应用于装配、加工、包装等各种自动上料工序。为了实现对轻、薄、小产品的平稳输送,笔者分析了基于系统共振方法的新型垂直驱动压电振动送料器,介绍了该种双晶片驱动式振动送料器的工作原理,建立了动力学模型,获得了系统固有频率表达式,通过样机制作和实验测试得到了系统固有频率以及振幅与输送速度的关系。     

激光对推扫相机的干扰

针对激光对推扫相机干扰效应及其干扰机理等疑难问题,构建了一套推扫相机激光干扰实验系统.描述了实验系统组成、实验方法和步骤,开展了激光对推扫相机干扰实验,给出了实验结果.从线阵CCD探测器的结构和图像处理层面出发,对出现的干扰现象进行了机理分析,利用实验数据拟合出了相机入瞳激光功率与干扰面积的对应关系,分析了影响推扫相机输出图像上激光干扰面积的主要因素,并与激光对凝视相机的干扰进行了比对分析.该研究成果可应用于激光对推扫相机干扰效果评价和相机激光防护研究等方面.     

铜框架表面氧化过程及氧化膜厚度测量

在集成电路封装过程中,表面氧化是制约铜框架大批量应用于生产的主要原因,而框架表面氧化程度的测量和管控是铜框架应用于封装的关键点。本文运用金属氧化理论阐述了铜框架表面氧化过程及机理;进行铜框架烘烤氧化实验后测量框架表面的氧化膜厚度,通过对测量数据拟合得到铜框架氧化膜生长曲线,从而可以预测铜框架在封装过程中的氧化程度,为集成电路封装工艺的设计和管控提供依据。     

镀铜厚度对裸铜框架抗氧化性能的影响

采用双臂电桥法测量了不同氧化程度的裸铜框架的电阻,在此基础上分析了烘箱内氧浓度、烘烤温度和框架表面镀铜厚度对框架氧化程度的影响。研究发现,在氧浓度≤0.1%的氮气保护环境中,经过180℃烘烤60 min后,裸铜框架的氧化程度大于无氮气保护下100℃烘烤60 min后的氧化程度;镀铜层能有效提高裸铜框架在100~180℃范围内的抗氧化能力,镀铜层较厚(1.0μm)的裸铜框架的抗氧化能力优于镀铜层较薄(0.5μm)的裸铜框架的抗氧化能力。     

Cu diffusion in Ag-plated Cu leadframe packages

Cu diffusion onto an Ag-plated Cu leadframe surface was detected by Energy Dispersive X-ray (EDX) after de-capsulating the molded package. However, no Cu was detected by EDX on the Ag surfaces of bare leadframe, leadframe after die attachment including die attachment curing, or leadframe after wire bonding. Temperature simulation of molding and post-molding curing show that the temperature and its duration have some impact on the Cu diffusion, which is as expected. Interestingly, this study shows that the Cu diffusion onto the interface of the Ag-plated surface and mold compound is very much dependent on the type of mold compound used, which has never been reported in the literature so far. The Cu diffusion was detected by EDX only for certain types of mold compounds used. It is concluded that the mold compound is a major contributor to the Cu diffusion observed. This is possibly because S and O in the mold compound react with Cu and form copper sulfides and copper oxides, which accelerate the Cu diffusion from the Cu leadframe substrate onto the interface of the Ag surface and mold compound.     

Distribution of a minor solid constituent in a transfer molded e-pad leadframe package

This study investigates the spatial distribution of a minor particulate constituent in a transfer molded exposed die paddle (e-pad) leadframe microcircuit package. Packages were polished at three depths parallel to its top surface. Levels 1 and 2 are above the die and leadframe while level 3 is just below the top surface of the die and leadframe. The distribution of area fraction and size of the particulate was analyzed for each level and with respect to the distance from the gate using micro-photographic image analysis. A nonuniform distribution of the particulate material for both particle size and location is evident, and its relations with gate, die, and leadframe are interpreted. ANOVA tests were conducted to assess the statistical significance of the variations.     

集成电路封装设计可靠性提高方法研究

集成电路封装是集成电路制造中的重要一环,集成电路封装的目的有：第一,对芯片进行保护,隔绝水汽灰尘以及防止氧化;第二,散热;第三,物理连接和电连接。在进行封装设计时,可以通过一些方法,增强产品的制造稳定性以及产品的可靠性。文章研究了引线框架、线弧、等离子清洗及塑封料对封装可靠性的影响以及一些获得高质量的方法。例如：引线框...     

稀土金属真空提纯炉的研制

介绍了一种用于稀土金属提纯的单晶炉,根据区熔法提纯单晶的特殊工艺要求,分析了其主要结构及特点。该设备也适用于多种激光晶体的生长和激光晶体的真空退火。     

集成电路塑封中引线框架使用要求

本文讲述了引线框架的主要特性以及引线框架对封装的影响,提出了一些改进方法。     

铝线键合的等离子清洗工艺研究

采用DOE(实验设计)方法,通过比较铝线拉力的数值、标准方差及PpK,得到最适合铝线键合工艺的等离子清洗功率、时间和气流速度参数的组合。同时分析了引线框架在料盒中的摆放位置对等离子清洗效果的影响,引线框架置于等离子气体浓度高的位置清洗效果较好,引线拉力值能获得更低的方差和更优的过程控制能力。     

Adhesion strength of leadframe/EMC interfaces

Cu-based leadframe sheets were oxidized in alkaline solutions to produce brown and/or black oxide on the surfaces, and molded with epoxy molding compound (EMC). The adhesion strength of leadframe/EMC interface was measured using sandwiched double-cantilever beam (SDCB) specimens and pull-out specimens. Results showed that the adhesion strength of leadframe/EMC interface was inherently very poor but could be increased drastically with the nucleation of acicular CuO precipitates. The presence of smooth-faceted Cu₂O on the surface of the leadframe gave close to zero fracture toughness (G_C) and suitable pull strength (PS). A direct correlation between G_C and PS showed that PS can be a measure of G_C only in a limited range.     

Study on the different procedures for debleeding of plastic dip

Inevitable wear on encapsulation molds and small variances in the leadframes cause a small amount of the molding compound or resin to leak out. The leakage results in either excess flash around the body of the plastic package or a thin transparent film on the leadframe and leads, which subsequently affect the solder-dipping that protects the leadframe from corrosion. Thus, effective debleeding procedure must be performed before the solder-dipping process. In this study, nine different flow procedures are designed. The results of the study show that the resin bleed can be more effectively removed by a debleeding procedure carried out immediately after molding rather than post-cure. The wet blasting process used for the debleeding purpose is also found not suitable as it causes side effects to the package surface and leadframe.