MEMS传感器的封装

首先通过对MEMS封装所面临的挑战进行分析,提出了MEMS封装所需要考虑的一些问题。然后从芯片级、晶片级和系统级三个方面详细介绍了倒装焊、BGA、WLP、MCM和3D封装等先进的封装技术,并给出了一些应用这些封装方式对MEMS系统封装的实例。最后对MEMS和MEMS封装的走向进行了展望,并对全集成MEMS系统的封装进行了一些探讨。     

MEMS器件的封装材料与封装工艺

随着各种MEMS新产品的不断问世,先进的MEMS器件的封装技术正在研发之中.本研究综述了MEMS的封装材料,包括陶瓷、塑料、金属材料和金属基复合材料等.阐述了MEMS的主要封装工艺和技术,包括圆片级封装、单芯片封装、多芯片组件和3D堆叠式封装等.并展望了MEMS器件封装的应用和发展前景.     

微系统与中规模器件的封装技术设计

文章主要论述了微机电系统(MEMS)和微系统诸如微传感器、驱动器和微流体元件的电机封装技术、封装等级和封装技术相关的问题.首先陈述并讨论了典型的MEMS产品诸如微压传感器、加速度计和微泵;微电子封装和微系统封装技术,重点阐述芯片级封装技术和器件级封装技术问题.芯片级封装技术主要涉及芯片钝化、芯片隔离和芯片压焊;器件级封...     

基于微谐振器的圆片级真空封装真空度测试技术

针对微电子机械系统(MEMS)圆片级封装腔体体积小、传统的真空封装测试方法适用性差的情况,研制了一种用于表征圆片级真空封装真空度的器件——MEMS微谐振器。利用此谐振器不仅可以表征圆片级真空封装真空度,也可用于圆片级真空封装漏率的测试。采用MEMS体硅工艺和共晶圆片键合技术实现了微谐振器的圆片级真空封装,利用微谐振器阻尼特性建立了谐振器品质因数与真空度的对应关系,通过设计的激励电路实现了微谐振器品质因数的在片测试,对不同键合腔体真空度下封装的MEMS微谐振器进行测试,测试结果显示该微谐振器在高真空度0.1～8 Pa范围内品质因数与真空度有很好的对应关系。     

微机电系统封装技术

首先提出了MEMS封装技术的一些基本要求,包括低应力、高真空、高气密性、高隔离度等,随后简要介绍了MEMS封装技术的分类.在此基础上,综述了三个微机电系统封装的关键技术:微盖封装、圆片级芯片尺寸封装和近气密封装,并介绍了其封装结构和工艺流程.     

东芝公开在前工序封装MEMS元件的技术

东芝5月30日公开了2种在前工序封装MEMS元件的技术。所以因其可在晶圆级进行成批处理,可降低一直视为MEMS元件制作难题的封装成本。该公司还层积以此封装技术制成的MEMS元件和驱动器IC,试制出了0．8mm厚的多芯片封装（MCP）。该公司介绍,0．8mm厚的MCP为全球最薄。     

热致封装效应对MEMS器件谐振特性 影响的单元库模型

 大量试验和数值仿真结果均已确认封装-器件的热失配对MEMS器件性能及可靠性有显著影响,即热致封装效应.然而迄今为止仍缺乏有效的物理模型对此加以系统描述.本文基于单元库法思想和节点法分析手段构建了MEMS热致封装效应的理论模型.通过对非器件结构如锚区、衬底等标准化单元建模,扩充了节点分析法在封装级MEMS仿真领域的应用.文中以常见MEMS基本器件和封装结构为例进行了研究,计算了热致封装效应对器件谐振特性的影响,并利用有限元仿真进行验证.最后讨论了封装级MEMS设计面临的挑战.     

一种真空度可调的圆片级封装技术

提出了一种MEMS器件的圆片级封装技术。通过金硅键合和DRIE通孔制备等关键工艺技术,可以实现真空度从102 Pa到2个大气压可调的圆片级封装。作为工艺验证,成功实现了圆片级真空封装MEMS陀螺仪的样品制备。对封装后的陀螺仪样品进行了剪切力和品质因数Q值测试,剪切力测试结果证明封装样品键合强度达到5 kg以上,圆片级真空封装后陀螺的品质因数Q值约为75 000,对该陀螺的品质因数进行了历时1年的跟踪测试,在此期间品质因数Q的最大变化量小于7‰,品质因数测试结果表明封装具有较好的真空特性。     

基于BCB键合的MEMS加速度计圆片级封装工艺

对基于BCB的圆片级封装工艺进行了研究,该工艺代表了MEMS加速度计传感器封装的发展趋势,是MEMS加速度计产业化的关键。选用3000系列BCB材料进行MENS传感器的粘结键合工艺试验,解决了圆片级封装问题,在低温250℃和适当压力辅助下≤2．5bar（1bar=100kPa）实现了加速度计的圆片级封装,并对相关的旋涂、键合、气氛、压力等诸多工艺参数进行了优化。     

电子元器件封装技术发展趋势

晶圆级封装、多芯片封装、系统封装和三维叠层封装是近几年来迅速发展的新型封装方式,在推动更高性能、更低功耗、更低成本和更小形状因子的产品上,先进封装技术发挥着至关重要的作用。晶圆级芯片尺寸封装(WCSP)应用范围在不断扩展,无源器件、分立器件、RF和存储器的比例不断提高。随着芯片尺寸和引脚数目的增加,板级可靠性成为一大挑战。系统封装(SIP)已经开始集成MEMS器件、逻辑电路和特定应用电路。使用TSV的三维封装技术可以为MEMS器件与其他芯片的叠层提供解决方案。     

MEMS封装技术及标准工艺研究

分析了MEMS的特点及封装工艺对MEMS的影响,给出了对MEMS封装的基本要求.研究了MEMS封装工艺中的一些关键技术,即硅-硅和硅-玻璃键合技术、清洗与引线键合技术、焊料贴片和胶粘技术以及气密封帽技术等,并给出了一些重要的研究结果.同时也介绍对几种MEMS惯性器件的封装要求及封装方法.     

A Novel Wafer-Level Hermetic Packaging for MEMS Devices

Some emerging microelectromechanical systems (MEMS) devices such as high-performance inertial sensors and high-speed actuators must be operated in a high vacuum and in order to create this vacuum environment, specific packaging is required. To satisfy this demand, this paper presents a novel method for hermetic and near-vacuum packaging of MEMS devices. We use wafer-level bonding technology to combine with vacuum packaging, simultaneously. For this packaging solution, the wafers with air-guided micro-through-holes were placed on a custom-built design housed in a vacuum chamber maintained at a low-pressure environment of sub-10 mtorr. Packaging structure is then sealed by solder ball reflow process with the lower heating temperature of 300degC to fill up micro-through-hole. Experimental results shown the hermetical packaging technique using solder sealing is adapted to the wafer-level microfabrication process for MEMS devices and can achieve better yield and performance. Thus, this technique is very useful for many applications with high performance and low packaging cost can be obtained due to wafer-level processing.     

MEMS局部加热封装技术与应用

随着半导体技术的发展,封装集成度不断提高,迫切需要发展一种低温封装与键合技术,满足热敏器件封装和热膨胀系数差较大的同质或异质材料间的键合需求。针对现有整体加热封装技术的不足,首先介绍了局部加热封装技术的原理与方法,然后对电流加热、激光加热、微波加热、感应加热和反应加热等几种局部加热封装技术进行了比较分析,最后具体介绍了局部加热封装技术在热敏器件封装、MEMS封装和异质材料集成等方面的应用。由于局部加热封装技术具有效率高、对器件热影响小等优点,有望在MEMS技术、系统封装(SiP)、三维封装及光电集成等领域得到广泛应用。     

Packaging for microelectromechanical and nanoelectromechanical systems

Packaging is a core technology for the advancement of microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS). We discuss MEMS packaging challenges in the context of functional interfaces, reliability, modeling and integration. These challenges are application-dependent; therefore, two case studies on accelerometers and BioMEMS are presented for an in-depth illustration. Presently, most NEMS are in the exploratory stage and hence a unique path to identify the relevant packaging issues for these devices has not been determined. We do, however, expect the self-assembly of nano-devices to play a key role in NEMS packaging. We demonstrate this point in two case studies, one on a silicon nanowire biosensor, and the other on self-assembly in molecular biology. MEMS/NEMS have the potential to have a tremendous impact on various sectors such as automotive, aerospace, heavy duty applications, and health care. Packaging engineers have an opportunity to make this impact a reality by developing low-cost, high-performance and high-reliability packaging solutions.     

集成电路封装中的引线键合技术

在回顾现有的引线键合技术之后,文章主要探讨了集成电路封装中引线键合技术的发展趋势。球形焊接工艺比楔形焊接工艺具有更多的优势,因而获得了广泛使用。传统的前向拱丝越来越难以满足目前封装的高密度要求,反向拱丝能满足非常低的弧高的要求。前向拱丝和反向拱丝工艺相结合,能适应复杂的多排引线键合和多芯片封装结构的要求。不断发展的引线键合技术使得引线键合工艺能继续满足封装日益发展的要求,为封装继续提供低成本解决方案。     

Study on the failure temperature of Ti/Pt/Au and Pt5Si2-Ti/Pt/Au metallization systems

The Ti/Pt/Au metallization system has an advantage of resisting KOH or TMAH solution etching. To form a good ohmic contact, the Ti/Pt/Au metallization system must be alloyed at 400℃. However, the process temperatures of typical MEMS packaging technologies, such as anodic bonding, glass solder bonding and eutectic bonding, generally exceed 400℃. It is puzzling if the Ti/Pt/Au system is destroyed during the subsequent packaging process. In the present work, the resistance of doped polysilicon resistors contacted by the Ti/Pt/Au metallization system that have undergone different temperatures and time are measured. The experimental results show that the ohmic contacts will be destroyed if heated to 500℃. But if a 20 nm Pt film is sputtered on heavily doped polysilicon and alloyed at 700℃ before sputtering Ti/Pt/Au films, the Pt₅Si₂-Ti/Pt/Au metallization system has a higher service temperature of 500℃, which exceeds process temperatures of most typical MEMS packaging technologies.     

The role of universities in electronic packaging engineering

Characteristics of present and future problems and directions in Level 1 and Level 2 packaging are discussed. Research areas are delineated, and problems amenable to attack by universities are suggested. An example of an existing university research program is given. Methods for universities to develop and implement courses in electronic packaging are discussed. A three-course core presently in use is described; this core can be used to provide Electronic Packaging Engineering emphasis in the M.S. programs of a number of different departments. Guidelines are suggested for the development of educational programs in Electronic Packaging Engineering, including use of industrial interactions and video education.     

MEMS后封装技术

通过对局部加热与压焊技术的研讨,介绍了微系统后封装技术,微系统封装技术在微电机系统(MEMS)蓬勃兴起的领域已成为主要的研究课题.构建多应用后封装工艺不仅推动了此领域的发展,而且加速了产品的商业化进程.文章概述了通过局部加热和压焊技术形成创新型后封装的方法,阐明了目前MEMS封装技术和晶片压焊工艺技术的工程基础.重点陈...     

大功率白光LED封装技术面临的挑战

发光二极管（LED）是一类可直接将电能转化为可见光和热等辐射能的发光器件,具有一系列优异特性,被认为是最有可能进入普通照明领域的一种“绿色照明光源”。目前市场上功率型LED还远达不到家庭日常照明的要求。封装技术是决定LED进入普通照明领域的关键技术之一。文章对LED芯片的最新研究成果以及封装的作用做了简单介绍,重点论述了封装的关键技术,包括共晶焊接、倒装焊接以及散热技术,最后指出了未来LED封装技术的发展趋势及面临的挑战。