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...     

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。     

T/R组件微组装中的压焊技术

简介了Ｔ／Ｒ 组件及压焊特点,列举了Ｔ／Ｒ 组件微组装中的常用几种压焊方法和应用范围,对梁式引线的压焊、各类基板的可靠压焊等进行了试验研究,最后讨论了压焊技术（ 设备、Ｔ／Ｒ组装设计等） 的发展趋势。     

集成电路封装压焊金丝选择之初探

在当前大量采用的集成电路传统封装工艺中，压焊是至关重要的加工工序，特别是选用的焊线材料是否合适，更是成为影响IC产品封装形式和内在质量的重要因素。压焊用材料大致可分为以下三类：金丝、硅铝丝、铜丝，目前半导体器件、集成电路封装产品中大量采用的是金丝。因此，本文仅对金丝的成分和选用时需要考虑的因素作一简单介绍，相信对直接从事封装技术工作的工程技术人员对金丝的了解、选型方面有所帮助。     

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.     

局部增强压焊块铝层厚度的工艺方法

针对目前铜线封装对芯片压焊块的铝层厚度要求较高的问题,通过改进芯片制造工艺流程,对芯片内部压焊块的铝层进行单独地加厚。以便同时满足芯片封装厂采用铜线打线和芯片制造厂金属刻蚀工艺难易的要求。做法为,在钝化层刻蚀完成后,再生长一层足够厚的金属层,进行钝化层反版的光刻以及湿法刻蚀,只保留下压焊块区域的金属层,此时压焊块区域就...     

金属丝自动压焊中的引线变换

引线变换,是引线框内所有能压焊的引线的平面座标对准。这是为了在金属丝压焊前确定(短路的或缺少的)引线的偏位和/或误差状态而使用的技术。 集成电路最流行的封装方法仍然是使用引线框。引线框之所以被IC工业广泛应用和采纳,是因为它们在组装、测试和使用上容易实现自动化。随着集成电路的复杂性日益增长、器件几何尺寸越来越小,引线框内的引线数也迅速增大。     

多次烧结和清洗对压焊工艺的影响

设计了一种应用于光电器件的多梯度烧结、多次清洗的微组装工艺.采用共晶焊将各芯片、元器件烧结到基板上,再将基板烧结到相应管腔内.同时,通过压焊工艺进行芯片与厚膜电路导带的互联.设计了相关工艺步骤,论证了多次烧结、清洗对压焊效果的影响.实验数据表明,采用所设计的工艺制作的样品在经历多次烧结、清洗步骤后,在压焊方面具有高的可靠性,为器件的后续制作奠定了良好的基础.     

基于晶圆键合的MEMS圆片级封装研究综述

为提升微机电系统（MEMS）器件的性能及可靠性,MEMS圆片级封装技术已成为突破MEMS器件实用化瓶颈的关键,其中基于晶圆键合的MEMS圆片级封装由于封装温度低、封装结构及工艺自由度高、封装可靠性强而备受产学界关注。总结了MEMS圆片级封装的主要功能及分类,阐明了基于晶圆键合的MEMS圆片级封装技术的优势。依次对平面互连型和垂直互连型2类基于晶圆键合的MEMS圆片级封装的技术背景、封装策略、技术利弊、特点及局限性展开了综述。通过总结MEMS圆片级封装的现状,展望其未来的发展趋势。     

微型PCR系统及其温控特性研究

介绍了一种基于芯片的微型聚合酶链式反应(polymerase chain reaction,PCR)系统,利用该系统进行了温度控制和响应特性研究.系统由PCR芯片、封装PCB板及单片机控制系统组成.PCR芯片采用MEMS技术制作.用微型PCR系统对芯片上含有微加热器的反应仓进行了升温降温、循环温度和液体负载对比加热等实验.结果显示:微加热器升温速度可以达到3 ℃/s,降温速度可以达到1℃/s,稳定后温度变化小于0.1 ℃.通过实验结果与理论计算的对比,分析了微加热器的最高温度与加热功率之间的对应关系及提高温控特性的关键因素.     

MEMS post-packaging by localized heating and bonding

This work addresses important post-packaging issues for microsystems and recommends specific research directions by localized heating and bonding. Micropackaging has become a major subject for both scientific research and industrial applications in the emerging field of microelectromechanical systems (MEMS). Establishing a versatile post-packaging process not only advances the field but also speeds up the product commercialization cycle. A review of engineering bases describing current technologies of MEMS packaging and wafer bonding is followed by an innovative post-packaging approach by localized heating and bonding, process demonstrations by selective encapsulation are presented, including an integrated low pressure chemical vapor deposition (LPCVD) sealing process, localized silicon-gold eutectic bonding, localized silicon-glass fusion bonding, localized solder bonding and localized CVD bonding processes.     

铝锗键合技术及其在MEMS加速度计中的应用

本文提出了一种可与CMOS工艺兼容的MEMS晶圆级铝锗键合工艺。根据铝锗共晶键合的特点,设计了键合工艺流程,并通过对键合工艺(包括键合温度、键合时间、键合压强)安排多次试验,获得了优化的铝锗共晶键合工艺条件,并成功应用于MEMS加速度计产品的制作。     

基于聚合物介质的低温硅硅键合研究

聚合物低温键合技术是MEMS器件圆片级封装的一项关键技术。以苯并环丁烯(BCB)、聚对二甲苯(Parylene)、聚酰亚胺(Polyimide)、有机玻璃(PMMA)作为键合介质,对键合的温度、压力、气氛、强度等工艺参数进行了研究,并分析了其优缺点。通过改变Parylene的旋涂、键合温度、键合压力、键合时间等工艺参数进行了优化实验。结果表明,在230 ℃的低温键合条件下封装后的MEMS器件具有良好的键合强度(＞3.600 MPa),可满足MEMS器件圆片级封装要求。     

Localized bonding processes for assembly and packaging of polymeric MEMS

Localized bonding schemes for the assembly and packaging of polymer-based microelectromechanical systems (MEMS) devices have been successfully demonstrated. These include three bonding systems of plastics-to-silicon, plastics-to-glass, and plastics-to-plastics combinations based on two bonding processes of localized resistive heating: 1) built-in resistive heaters and 2) reusable resistive heaters. In the prototype demonstrations, aluminum thin films are deposited and patterned as resistive heaters and plastic materials are locally melted and solidified for bonding. A typical contact pressure of 0.4 MPa is applied to assure intimate contact of the two bonding substrates and the localized bonding process is completed within less than 0.25 s of heating. It is estimated that the local temperature at the bonding interface can reach above 150/spl deg/C while the substrate temperature away from the heaters can be controlled to be under 40/spl deg/C during the bonding process. The approach of localized heating for bonding of plastic materials while maintaining low temperature globally enables direct sealing of polymer-based MEMS without dispensing additional adhesives or damaging preexisting, temperature-sensitive substances. Furthermore, water encapsulation by plastics-to-plastics bonding is successfully performed to demonstrate the capability of low temperature processing. As such, this technique can be applied broadly in plastic assembly, packaging, and liquid encapsulation for microsystems, including microfluidic devices.     

Ultrasonic bonding for thermoplastic microfluidic devices without energy director

Thermal assisted ultrasonic bonding and solvent assisted ultrasonic bonding for thermoplastic microfluidic devices are proposed in this paper. Both of these two methods are non-molten bonding, energy director is not employed and thus avoided the problem of controlling the molten polymer flow along the microstructure during bonding process. Ultrasonic bonding system and interfacial temperature testing system were established. The critical amplitude for bonding was chosen by interfacial temperature tests to keep the bonding interface below glass transition temperature (T_g) of the polymer. Polymethylmethacrylate (PMMA) microfluidic devices were bonded by both thermal assisted ultrasonic bonding and solvent assisted ultrasonic bonding with the bonding time of 30 s and 20 s, respectively, while the tensile strength of 0.95 MPa and 2.25 MPa, respectively. The bonding area was 27 mm × 51 mm, the maximum dimension loss for the microstructure was 0.66% ± 0.60. A four-layer PMMA microfluidic device was also bonded using thermal assisted ultrasonic bonding, demonstrated the advantage of localized heating character of ultrasonic bonding and did some preliminary work in multilayer polymer MEMS device bonding. This paper provided the potential high throughput bonding methods for mass production of polymer microfluidic devices.     

用于MEMS器件的键合工艺研究进展

随着MEMS器件的广泛研究和快速进步,非硅基材料被广泛用于MEMS器件中.键合技术成为MEMS器件制作、组装和封装的关键性技术之一,它不仅可以降低工艺的复杂性,而且使许多新技术和新应用在MEMS器件中得以实现.目前主要的键合技术包括直接键合、阳极键合、粘结剂键合和共晶键合.     

Thermal challenges in MEMS applications: phase change phenomena and thermal bonding processes

Two thermal challenges for current and next generation microelectromechanical systems (MEMS) applications are discussed. The first topic is the fundamental investigations of phase change phenomena in the microscale. It has been demonstrated that microresistive heaters can generate single, spherical and controllable thermal bubbles with diameters between 2 and 500 μm. Both simplified steady state and transient analyses that provide the scientific foundation of bubble nucleation in the microscale have been established but require further investigations. Several device demonstrations are briefed including microbubble-powered actuators, microbubble-powered nozzle-diffuser pumps and microbubble-powered micromixers for applications in microfluidic systems. The second topic addresses key heat transfer issues during the thermal bonding processes for MEMS fabrication and packaging applications. Basic thermal analyses on the microscale bonding processes have been developed while in-depth study is required to advance the understandings of the thermal bonding processes in the microscale. Successful new thermal bonding processes are introduced, including localized eutectic bonding, localized fusion bonding, localized chemical vapor deposition (CVD) bonding, localized solder bonding and nanosecond laser bonding for encapsulation of MEMS devices.     

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.     

硅MEMS器件键合强度在线检测方法

键合强度是MEMS器件研制中一个重要的工艺质量参数,键合强度检测对器件的可靠性具有十分重要的作用。为了获得MEMS器件制造工艺中的键合强度,提出了一种键合强度在线检测方法,并基于MEMS叉指式器件工艺介绍了一种新型键合强度检测结构;借助于材料力学的相关知识,推导出了键合强度计算公式,经过工艺实验,获得了键合强度检测数据;对获得的不同键合面积的键合强度加以对比,指出这些数据的较小差异,是由刻度盘最小刻度误差和尺度效应造成的。结合叉指式器件的工作环境,认为这种方法获得的键合强度更接近实际的工作情况。