塑封微电子器件失效机理研究进展

塑封器件在现在的封装产业中具有无可比拟的优势,相关研究引起了人们广泛关注.简要介绍了塑封微电子器件的发展史,以及国内外塑封器件可靠性的研究现状.对塑封器件的主要失效机理研究进展进行深入探讨,如腐蚀、分层、开裂等,提出了几种提高塑封器件可靠性的措施.论述了用于塑封器件质量评估的试验方法,并展望了塑封器件在军工领域的潜在应用前景.     

新型塑封器件开封方法以及封装缺陷

随着塑封器件(PEMs)质量和可靠性的不断提高,塑封器件的应用领域进一步扩展,也逐步应用于军事领域.去除塑料包封层,露出芯片表面,是DPA(破坏性物理分析)及FA(失效分析)的关键一步.对塑封器件的开封技术进行了简要的介绍,并对开封中发现的一些失效模式进行分析.通过对塑封器件开封方法的研究,确保塑封器件的开封质量,为进一步对塑封器件进行DPA和失效分析建立了基础.     

集成电路封装用绝缘胶漏电失效分析

在电子元器件封装领域中,塑封器件正逐步替代气密性封装器件。目前工业级塑封器件已不能满足器件的高可靠性要求,工业级塑封器件在严酷的环境应力试验中经常出现失效。研究了工业级塑封器件在可靠性筛选试验中出现失效的问题,通过X射线观察和芯片切面分析等方法,查明了造成器件失效的原因,并提出了优化改进措施。     

塑封器件分层失效实例分析

微电子塑封器件常用的环氧树脂塑封料,因其极易吸收周围环境里的水汽而严重影响塑封器件的可靠性。通过一个实例分析,分别从故障定位、机理讨论以及改进措施3个方面对塑封器件分层失效进行详细的论述,从而有效而快速地提升塑封器件可靠性。     

高可靠领域中应用塑封器件的有效评价

介绍了塑封器件的优缺点以及发展情况,针对塑封半导体器件本身在材料、结构和工艺等方面的特点,对塑封器件的失效模式和在试验中暴露的问题进行探讨,针对塑封器件的温度适应性、密封性、工艺控制及使用长期可靠性方面制定了相应的质量评价方案。半导体塑封器件通过质量评价方案的试验项目,包括筛选试验、可靠性鉴定试验和破坏性物理分析(DPA)三方面的试验,降低了塑封器件在应用中的风险,对我国高可靠领域中对塑封器件的选用具有一定的借鉴意义。     

塑封半导体器件的可靠性增长分析

应用ＥＤＲＩＣ可靠性模型对彩电配套用塑封整流二极管进行了增长分析,讨论了该器件的失效模式、失效机理及增长对策,使该器件的可靠性得到了较大的增长。     

微电子器件塑封损伤机理分析

分析了塑封微电子器件的失效模式及损伤机理 ,在此基础上讨论了提高塑封器件可靠性的对策及应用前景。     

综合湿热及蒸汽压力对塑封IC器件可靠性影响的分析方法进展

随着微电子塑料封装IC器件吸潮可靠性影响的深入研究,综合分析热、湿及蒸汽压力对塑封器件的可靠性影响是必不可少的工具。本文从理论、模拟分析的角度,回顾并分析了综合考虑热,湿及蒸汽压力对塑封IC器件可靠性影响的分析方法;从已有的理论方法和研究结论来看,综合考虑热、湿及蒸汽压力对器件失效影响更精确的表征了器件的实际失效情况,正成为微电子封装可靠性研究领域的热点,其研究思路受到了越来越多的关注和重视。     

塑封器件无损开封技术介绍

随着现代微电子行业的发展,对产品质量和结构安全性、使用可靠性提出了越来越高的要求。由于无损检测（NTD）技术具有不破坏试件、检测灵敏度高等优点,其应用日益广泛。塑封材料又以其低成本、生产工艺简单、适合大规模生产等特点,占据了整个微电子封装材料97％以上的市场。文章对塑封器件的开封技术及需要注意的事项进行了较详细的介绍和说明,列出了针对各种封装形式的无损开封方案,为无损开封的实际应用提供了便利。通过对塑封器件开封办法的研究,确保塑封器件的开封质量,为进一步对塑封器件进行DPA和失效分析建立了基础。     

基于建模仿真的塑封光电耦合器失效分析

首先,对塑封光电耦合器失效分析的现有方法及其作用进行了阐述;然后,介绍了塑封光电耦合器常见的失效模式及建模仿真分析思路;最后,对于塑封光电耦合器的封装材料进行了简要的分析,对于提高光电耦合器件的可靠性具有一定的指导意义。     

Plastic-encapsulated microcircuit reliability andcost-effectiveness study

This study evaluates the reliability and cost-effectiveness of using commercial plastic-encapsulated microcircuits (PEM) in a typical military system, with a view to increasing their acceptability in military applications. The cost comparison indicates an average 6-fold decrease in cost when commercial devices are used. Assurance testing did not reveal any special problems with commercial parts. Thus, if commercial PEM were proven to be sufficiently reliable for an intended military application, large cost savings would be gained by using them instead of hermetic packages. The 4.5 sigma enhanced inspection program and the process-control methods suggested here would enhance the manufacturing yield of the PLGR (precision lightweight global positioning system receiver) by encouraging improvements in the manufacturing process while simultaneously cutting the cost of a 100% rescreen to qualify the final product. Neither the requirements assurance tests (including the step-stress test-analyze-and-fix test), nor the reliability demonstration test, nor the operational test, showed more failures than are typical for any new development, and no problems unique to PEM were observed. Thus, the use of PEM did not lead to any special problems that caused PLGR-use specifications to be violated. Complete failure analysis of the isolated parts is in progress, and the results will help to understand the specific reliability issues involved with the use of PEM in military systems. These issues can then be addressed to improve the acceptability of such devices in future military applications     

The appropriateness of plastic encapsulated microcircuits in aspecific wooden-round application

Improvements in design, materials, and processes of plastic encapsulated microcircuits (PEM) have increased their reliability dramatically, to the point where PEM can achieve the `20-year lifetime in unpowered storage' required by certain wooden-round applications. PEM are now the parts of choice from cost, market-availability, performance, and reliability viewpoints. Nevertheless, PEM require appropriate vendor selection, verification by highly accelerated stress test (HAST), and manufacturing precautions. The potential failure mechanisms of package damage, internal part corrosion, and intermetallic growth, due to high temperature and humidity exposure, have been largely eliminated by improvements in the plastic and in the assembly process, and by the addition of die passivation. Models and test methodologies for accelerating (and thereby identifying) these physical phenomena have been developed, proven by testing, and generally accepted within the industry. After thoroughly defining the application temperature/humidity environments, the models are used to define a test program to qualify candidate PEM. This program consists of a high temperature life test, a humidity/temperature HAST and a completely assembled board-level HAST. To insure that subsequent manufacturing processes at Textron DS (including higher assemblies) do not damage qualified PEM, the manufacturing flow has been modified to minimize human contact with components, to eliminate any potentially corrosive chemical interaction with PEM, and to minimize exposure to moisture     

热膨胀系数不匹配导致的塑封器件失效

塑封器件使用过程中由于塑封材料和芯片之间热膨胀系数的不匹配,导致在外界温度变化时的应力释放对芯片造成损伤。文中通过VLSI失效分析,对这种应力造成的芯片损伤进行了研究,并提出利用环境应力试验和可靠性分析的方法暴露热膨胀系数不匹配导致芯片损伤的技术。     

Demonstrated reliability of plastic-encapsulated microcircuits formissile applications

For the past decade, overall reliability improvement and product availability have enabled plastic encapsulated microcircuits (PEM) to move from consumer electronics beyond the relatively large and reliability-conscious automotive market, into the military market. Based on the analysis of the worst-case PEM scenario for military applications, demonstrating the moisture reliability under long-term (20 years) dormant storage environments has become the last hurdle for PEM. Studies have demonstrated that PEM can meet the typical missile environments in long-term storage. To further validate PEM reliability in missile applications, Texas Instruments (TI) conducted three separate studies involving 6 years of PEM moisture-life monitoring and assessment, testing of the standard PEM electrical characteristics under the military temperature ranges (-55°C to +125°C), and assessing their robustness in moisture environments after the assembly processes. These TI studies support the use of PEM in missile (or similar) applications. Effective focus on part and supplier selection, supplier teaming, and process monitoring is necessary to maintain the PEM reliability over the required environments at the lowest cost. This paper assesses PEM reliability for a selected missile storage environment using the industry-standard moisture testing, such as biased HAST or 85°C/85%RH (relative humidity), for demonstrating the PEM moisture survivability. The moisture reliability (MTTF) or average moisture lifetime of PEM is assessed to correlate PEM capability to anticipated field-performance environments     

Reliability comparisons for plastic-encapsulated microcircuits

This paper briefly compares reliability test data obtained from plastic encapsulated microcircuits (PEM) purchased from various manufacturers. Tests include biased humidity, temperature cycling, autoclave, and life tests. The results indicate differences in reliability associated with PEM from the various manufacturers. These data highlight the need for a thorough understanding of supplier quality and reliability     

国外塑封微电路的可靠性研究进展

目前,国外对塑封微电路（ＰＥＭ）的可靠性研究主要集中在如下几个方面：ＰＥＭ的低温分层、失效分析、鉴定试验、长期贮存可靠性评价以及ＰＥＭ在军用电子设备中的应用等,对此进行了综述。     

Reliability assessment of fielded plastic and hermetically packagedmicroelectronics

This paper presents the results from multiple studies at Honeywell, of piece-part failure rates experienced in field use. These studies consider 7 line-replaceable-units (LRU), containing either hermetically sealed microcircuits (HSM) or plastic encapsulated microcircuits (PEM) or both. This paper compares the resulting field failure rates (λ) of HSM and PEM: digital devices: λ_PEM≈0.5λ_HSM; linear devices: λ_PEM≈3λ_HSM; only a small fraction of the linear devices degraded in performance at 125°C, though their performance at room temperature was within specification. The latter two points suggest that linear devices might require more attention relative to characterization over temperature and application considerations than do digital devices     

Plastic packaging is highly reliable

Plastic encapsulation is now a high reliability (HiRel) method of packaging active semiconductor devices and microelectronics in general. This paper shows that the traditional requirement for hermetic packaging can be overturned in favor of plastic packaging, on the following grounds: the full range of laboratory evidence of HiRel silicone junction coated IC undertaken by many researchers, showing that plastic encapsulations can now be used for microelectronics and optoelectronics in telecommunication, automotive, military and space applications as the better option in many instances; the inadequacy of the Mil-Std hermeticity specification; the demonstrated field failures of Mil-Std-883 hermetic packaged devices and the massive ingress of moisture, which caused many failures of telecommunication switching systems; and the demonstrated better field-reliability in rural tropical climates, of assessed, standard PEM from major manufacturers     

军品用塑封器件质量控制研究

塑封器件具有体积小、重量轻、易购买等优点,不可避免地被军工领域所采用。为保证军工产品质量,应针对塑封器件结构特点、主要失效机理及其质量现状,从采购渠道、入厂检验、贮存环境以及使用环节等方面入手,把控塑封器件的质量。     

Plastic encapsulated microcircuit reliability predicition: why?

Reliability prediction models for microcircuits have been a function of steady-state temperature. Failure rates generated from accelerated temperature tests were extrapolated to predict system reliability at system use temperatures. This is now known to be completely inaccurate. Attempts are now being made to predict the reliability of plastic encapsulated microcircuits (PEMs) based on accelerated temperature/humidity testing. Failure rates generated due to corrosion failure mechanisms at these high stress levels are then extrapolated and used to predict system reliability at used temperature/humidity conditions.This paper discusses the fallacy of this approach. A new concept for the assurance of PEM corrosion resistance is proposed. It will be shown that today's best commercial practice suppliers have already addressed the design, materials, and processing issues of molded packaged microcircuits, and corrosion is no longer a mechanism of concern to the user.