车载倒车影像DC/DC电源芯片故障原因分析

本文描述了车载倒车影像失效分析过程。着重从电学分析、破坏性物理分析等手段定位了分析了DC/DC电源芯片失效点,从车载工况角度分析了引发芯片故障的原因。本文提供一套便捷、实用、高效的芯片失效分析方案(从板级到晶圆级分析),通过常用的测试手段快速有效地定位芯片失效位置,分析出失效应力来源于车身其他电器,并提出改善方案。     

应用于MEMS的芯片倒装技术

通过对芯片倒装技术尤其是凸点加工工艺在MEMS设计中的作用进行实例分析,指出倒装芯片不仅是一种高性能的封装模式,还能为MEMS器件提供立体通道或是力热载体,并形成许多特殊的结构.在MEMS的加工过程中,可以充分考虑芯片倒装技术所带来的加工便利.     

抗辐照加固BICMOS结构电路的版图简化设计

就金属-氧化物-半导体(MOS)器件和双极器件混合结构(BICMOS)电路的抗辐照加固技术的设计而言,器件种类多会导致在硅工艺实现上的复杂性和失效问题.就此,提出了一种新的抗辐照加固设计方案.利用MOS器件抗辐照加固工艺的设计规则,完成对双极器件的版图集成,实现BICMOS结构的电路功能.最终,以通信接口类芯片产品中常用的振荡器单元为例进行仿真验证,达到设计要求.     

基于PFMEA的集成电路芯片银导电胶粘接工艺可靠性研究

微电子封装中,芯片银导电胶粘接工艺的质量会直接影响集成电路的可靠性。针对银导电胶粘接工艺的可靠性问题,本文提出了一种基于PFMEA的芯片粘接工艺风险识别方法,通过开展潜在失效模式分析,找到了芯片粘接工艺中的高风险环节,并制定了相应控制方法,有效提升了芯片粘接工艺质量,为微电子封装工艺开展PFMEA分析提供参考依据。     

三层硅加速度敏感芯片BCB键合工艺研究

采用非光敏苯并环丁烯﹙BCB﹚进行MEMS压阻式加速度敏感芯片三层结构制作。BCB键合具有工艺温度低、键合表面要求低等特点,适用于芯片的圆片级封装。但是固化过程中BCB粘度随温度升高而下降,流动性变大,在毛细作用的影响下沿着微小间隙流淌,导致可动部件粘连,器件失效。通过控制BCB厚度、增加BCB阻挡槽解决了可动部件粘连问题,制作了三层硅结构的加速度敏感芯片。样品漏率小于1.0×10 10Pa.m3/s,键合剪切强度大于20 MPa,能够满足航天、工业、消费电子等各领域的应用需求。     

集成电路的原理及可靠性分析

集成电路(Integrated Circuit,通常简称IC),是指将很多微电子器件集成在芯片上的一种高级微电子器件。本文通过分析集成电路失效模型,对集成电路可靠性进行了理论探讨,从而提高集成电路的质量。     

三层硅加速度敏感芯片BCB键合工艺研究

采用非光敏苯并环丁烯(BCB)进行MEMS压阻式加速度敏感芯片三层结构制作.BCB键合具有工艺温度低、键合表面要求低等特点,适用于芯片的圆片级封装.但是固化过程中BCB粘度随温度升高而下降,流动性变大,在毛细作用的影响下沿着微小间隙流淌,导致可动部件粘连,器件失效.通过控制BCB厚度、增加BCB阻挡槽解决了可动部件粘连问题,制作了三层硅结构的加速度敏感芯片.样品漏率小于1.0×10-10pa.m3/s,键合剪切强度大于20 MPa,能够满足航天、工业、消费电子等各领域的应用需求.     

低压差电压调整器TPS767D318失效研究

随着航空事业的大力发展,机载电子产品的质量和可靠性越发受到重视,其中重视对产品的芯片失效研究很有必要,本文通过外部与内部目检、芯片端口I-V特性测试、功能测试和分析等手段找到芯片失效原因,最后提出措施以避免发生产品批次性质量事故。     

运用精益六西格玛降低分立器件芯片测试设备的故障率

目的:为了提高芯片测试工序的测试产能,通过改进分立器件芯片测试工序的设备管理与流程,降低生产设备的故障率。方法:采用精益六西格玛,并通过其定义、测量、分析、改进、控制5个步骤研究,改进我公司分立器件芯片测试工序的设备管理与流程。结果:设备故障率由改进前的2.5%降低到1.4%。结论:精益六西格玛可减少设备管理与流程中存在的缺陷,降低分立器件生产设备的故障率,以便进一步提高芯片测试产能和设备管理水平。     

TDI CCD器件电性模拟器的设计

为了解决由TDI CCD芯片供货不及时、容易损坏而又价格昂贵等因素给TDI CCD相机的电路调试阶段的工作带来的不便.设计了一款TDI CCD电性模拟器.此器件采用以高速运算放大器作输入,FPCA作主控,高速DAC作数模转换,高速运放作输出的结构.它能较好的模拟TDI CCD器件电输入输出性能,能在不用TDI CCD芯片的条件下,完成各种相关的实验工作.     

GaAs HBT中测信号防护处理

在集成电路前段代工厂制作完成后,为确保出货电性及封装良率,客户会要求出货前对器件进行电性及可靠度测试。由于HBT砷化镓芯片高集成度及高频等因素,在中测时存在振荡与干扰,无法得到真实的电性良率,而且不同于手动探针台每次只测试单一测试项,中测要对晶粒同时进行所有电性测试,进一步造成电性良率失真。针对此问题,对中测探针卡进行改良,通过比较TaN片电阻均匀性与手动探针台测量结果,以及观察电流值的高斯分布,证实中测结果的合理性。结果表明,对探针卡进行电磁屏蔽及电路匹配后,改善前后电性良率有显著提升,能满足快速且准确的检测目的。     

基于MSP430的硒鼓芯片复位装置的设计

针对激光打印耗材生产厂家硒鼓生产过程中需对硒鼓芯片进行再利用的问题,设计了一种基于MSP430的硒鼓芯片复位装置.利用该装置可以复位不同型号的硒鼓芯片,从而使硒鼓芯片可循环利用,以达到节约生产成本、保护环境的目的.该装置同时具有复位效果好、易于操作的优点.     

Monolithic fabrication of electro-fluidic polymer microchips

Integration of electronic wiring with microfluidic chips is an important process as it allows electrical interactions with the fluidic media, for example required for resistive and capacitive sensing. It is also necessary in order to implement various actuation and control mechanisms such as pumping, electrophoresis and temperature control. Typically electrical wire traces are added to microfabricated fluidic chips using metal deposition processes that are carried out after the fluidic chip has been fabricated. The process for adding the wiring is complicated and is limited to select metals that can be deposited by evaporation or sputtering. We present a single step method for integrating electrical wires into polymer microfluidic chips that are fabricated by a hot embossing process. This process can flexibly embed any kind of commercially available metal wire with a microfluidic chip and the wiring may be integrated to come into surface contact with the fluid or may be embedded in close proximity to (but insulated from)the fluid paths for example for local heating purposes. This method significantly reduces total processing time and is thus a valuable method for wire integration into polymer chips. We demonstrate two applications—a microelectrolysis chip and a heater chip that were fabricated using this methodology. The design, fabrication process and the initial test results are presented.     

A low-cost through via interconnection for ISM WLP

Wafer level packaging (WLP) for image sensor device has the advantage of small size, high performance and low cost. In WLP technology, in order to form electrical interconnection from image sensor contact pad to the backside of the wafer, several structures have been developed, such as T-contact and through silicon via (TSV). In this paper, a wafer level package of image sensor with new type TSV electrical interconnection for image sensor pad is presented. The target of this development is to reduce process cost and difficulty, and increase yield of image sensor packaging. Key fabrication processes includes glass protecting wafer bonding, device wafer thinning, backside through via etching, via passivation layer deposition, pad oxide opening, via filling and backside re-routing layer formation, etc. Compared to large opening area of tapered via on the backside of CMOS image sensor wafer, only small opening area is need for making via interconnection with vertical sidewall presented in this paper. A fillet structure at bottom corner of via holes can help to reduce sequent process difficulty, so that low-cost and simplified unit processes are successfully adopted in the fabrication process for through via formation. The through via interconnection shows good electrical connection performance, and high-quality photo images are obtained by packaged image sensor device.     

基于MQ-7传感器煤气报警系统

为了能够实时监控室内天然气泄漏情况,采用半导体MQ-7传感器为数据采集元件,以AT89S52单片机为主控制核心,设计了一种天然气报警系统。系统根据环境状况作处判断,自动开启排气装置和语音报警装置,实现了自动报警、自动处理警情、自动检测全过程自动化。具有实时跟踪显示室内天然气浓度,实时监控天然气泄漏。经Proteus软件仿真表明,该系统可快速准确的检测被测气体中CO浓度,硬件部分具有可靠性高、实用性强、便于扩展等优点。     

Development and optimization of the laser-assisted bonding process for a flip chip package

In a fine pitch flip chip package, a laser-assisted bonding (LAB) technology has recently been developed to overcome several reliability and throughput issues in the conventional mass reflow (MR) and thermal compression bonding technology. This study investigated the LAB process for a flip chip package with a copper (Cu) pillar bump using numerical heat transfer and thermo-mechanical analysis. During the LAB process, the temperature of the silicon die was uniform across the entire surface and increased to 280 °C within a few seconds; this was high enough to melt the solder. The heat in the die was quickly conducted to the substrate through the Cu pillar bumps. Meanwhile, the substrate temperature was low and remained constant. Therefore, a stable solder interconnection was quickly achieved with minimal stress and thermal damage to the package. The substrate thickness, the number of Cu bumps, and the bonding stage temperature were found to be important factors affecting the heat transfer behavior of the package. The temperature of the die decreased when a thinner substrate, a higher number of Cu bumps, and a lower bonding stage temperature were used. If the temperature of the die was not sufficiently high, insufficient heat was transferred to the solder to melt it, resulting in incomplete solder joint formation. Thermo-mechanical analysis also showed that the LAB process produced lower warpage and thermo-mechanical strain than the conventional MR process. These results indicated that a LAB process using a selective local heating method would be beneficial in reducing thermo-mechanical stress and increasing throughput for the fine pitch flip chip packages.

     

全自动轴类直线度测量及调整装置设计

轴类工件的直线度调整方法需要调直和检测功能相互配合完成,一般需要两套设备或装置。通过设计一种基于DSP主控芯片技术的智能化测量调直装置,实现一台设备同步完成调直和检测。该设备设有检测工位和调直工位,工位可自动切换,设备可根据对轴类件直线度指标的检测结果,自行判断合格情况并对不满足设计要求的工件进行调直处理,直至其直线度合格。以DSP芯片为核心的嵌入式开发包,实现对激光传感器、压力传感器及电气执行单元的集成控制。软件采用CCS3.3开发环境,通过开发调直下压量自反馈机制和圆周跳动测量数据拟合程序,解决设备实现自动闭环控制的关键技术难题。调直检测实验结果表明,该设备可实现对轴类工件的全闭环智能自动检测及调直,直线度指标圆周跳动量小于0.05mm,可大幅减提高轴类工件的直线度水平。     

基于打印机的硒鼓芯片批量检测装置

针对当前打印耗材生产厂家硒鼓生产过程中需对采购硒鼓芯片进行检测的问题,设计了一种基于打印机的硒鼓芯片批量检测装置。该装置利用打印机上电自检过程来实现对同一型号10个硒鼓芯片单元的批量检测,具有检测速度快,易于操作的优点。     

高量程MEMS加速度计封装工艺研究

对一种先进的双悬臂梁高量程MEMS加速度计的单芯片封装工艺进行了失效机理分析。手工粘贴芯片盖板可靠性不高,加速度计失效是由于胶粘剂(粘贴胶或灌封胶 )从芯片盖板和芯片的间隙流淌进入悬臂梁的过载保护间隙,阻碍了悬臂梁的摆动。高量程加速度计采用单芯片封装方法时,存在芯片正面和背面保护的可靠性问题,更好的封装方法是采用圆片级封装。黑胶不适宜用作加速度计的贴片胶,至少使用聚酰亚胺膜作背面保护时如此。     

An electrohydrodynamic polarization micropump for electroniccooling

This paper presents the design, fabrication, and characterization of an innovative microcooling device for microelectronics applications. The device incorporates an active evaporative cooling surface, a polarization micropump, and temperature sensors into a single chip. The micropump provides the required pumping action to bring the working fluid to the evaporating surface, allowing the effective heat transfer coefficient through a thin-film evaporation/boiling process. The device is based on VLSI microfabrication technology, allowing the electrohydrodynamic (EHD) electrodes to be integrated directly onto the cooling surface. Since the EHD electrodes are fabricated using the same technology as the electronic systems themselves, the proposed microelectronic cooling system in the form of an integrated microchip is very suitable for mass production. The prototype devices demonstrated a maximum cooling capacity of 65 W/cm² with a corresponding pumping head of 250 Pa. The results of this investigation will assist in the development of future microcooling devices capable of operating at high power levels