功率MOSFET器件安全工作区的研究

功率金属氧化物半导体场效应晶体管(MOSFET)的热不稳定现象,限制了MOSFET的安全工作区。为得到符合实际的安全工作区,建立了一种分析模型,综合考虑了电流温度系数、热阻等因素,分析解释热不稳定产生条件,通过与实验数据的对比,证明了模型的正确性,得到了更符合实际的安全工作区。     

海洋环境下晶体管加速腐蚀试验中的问题探究

在模拟海洋环境下进行了3组不同盐溶液浓度的晶体管加速腐蚀试验,对试验样品得到的腐蚀结果进行了研究。对晶体管管壳的腐蚀速度随着浓度的增加而下降的原因进行了分析,阐述了晶体管管壳、涂层和外引线的腐蚀机理。另外,试验结果表明,晶体管外引线断裂现象依然是晶体管工艺生产过程中存在的亟需解决的问题。     

嵌入式操作系统Nucleus的移植研究

嵌入式系统作为计算机应用的一个崭新领域,以其简洁、高效等优点越来越多地受到人们的关注,而要开发一个嵌入式应用系统,则需要嵌入式硬件、嵌入式操作系统及相应的开发工具等。其中嵌入式操作系统是嵌入式应用系统中的基础部分,占有十分重要的地位,针对不同硬件平台。往往要进行嵌入式操作系统的移植。Nucleus是一种典型的嵌入式操作系统,具有体积小、功能强大、易于定制等特点,通过对Nucleus系统结构特点的分析,在基于SEP4020微处理器的评估板上,详细地论述了将嵌入式Nucleus操作系统移植到具体硬件平台上需要完成的工作。     

基于SEP4020的嵌入式音频系统设计

SEP4020是东南大学ASIC中心自主开发的一款基于ARM7TDMI核的微处理器,通过IIS音频总线与UDA1341型CODEC构成一种嵌入式音频系统,实现音频的播放和采集。该文介绍了基于SEP4020和IIS总线的嵌入式音频设备的硬件体系结构及其驱动程序的设计。给出相关硬件电路的说明及嵌入式系统下音频驱动程序的设计要点。     

基于加速退化晶体管贮存寿命的评估

为探求快速评价国产晶体管长期贮存寿命的方法,对国产3DK105B型晶体管开展了加速退化试验的分析和研究。通过三组不同温、湿度恒定应力的加速退化试验,确定了晶体管的失效敏感参数,利用其性能退化数据外推出样品的寿命;给出了常见的三种分布下的平均寿命,并结合Peck温湿度模型外推出自然贮存条件下本批晶体管的贮存寿命。最后分析了试验样品性能参数退化的原因。试验结果可以为评估国产晶体管的贮存可靠性水平提供一定的参考。     

晶体管电流增益的表达式修正及电流增益在可靠性评估中的应用

Considering the impacts of ideal factor n, VBE and band gap changes with the temperature on current gain, the current gain expression has been corrected to make the results closer to the actual test. Besides, the accelerating lifetime study method in the constant temperature-humidity stress is used to estimate the reliability of the same batch transistors. Applying the revised findings from the expression, the current gains before and after the test are compared and analyzed, and, according to the degradation data of the current gain, the transistor lifetimes in the test stress are respectively extrapolated in the different failure criteria.     

双极型晶体管电流增益温度特性的研究

修正了电流增益表达式。对样品3DK105B在不同温度点下进行测试分析。考虑样品理想因子n随温度的变化、VBE随温度的变化,以及禁带宽度随温度变化对电流增益的影响,对电流增益表达式进行了修正,使修正后的结果更加接近实际测试结果。     

嵌入式操作系统Nucleus的移植研究

嵌入式系统作为计算机应用的一个崭新领域,以其简洁、高效等优点越来越多地受到人们的关注,而要开发一个嵌入式应用系统,则需要嵌入式硬件、嵌入式操作系统及相应的开发工具等。其中嵌入式操作系统是嵌入式应用系统中的基础部分,占有十分重要的地位,针对不同硬件平台,往往要进行嵌入式操作系统的移植。Nucleus是一种典型的嵌入式操作系统,具有体积小、功能强大、易于定制等特点,通过对Nucleus系统结构特点的分析,在基于SEP4020微处理器的评估板上,详细地论述了将嵌入式Nucleus操作系统移植到具体硬件平台上需要完成的工作。     

基于性能退化数据的晶体管贮存寿命研究

NPN-type small and medium power switching transistors in 3DK series are used to conduct analyses and studies of accelerating degradation. Through three group studies of accelerating degradation in different temperature-humidity constant stresses, the failure sensitive parameters of transistors are identified and the lifetime of samples is extrapolated from the performance degradation data. Average lifetimes in three common distributions are given, when, combined with the Hallberg-Peck temperature-humidity model, the storage lifetime of transistor samples in the natural storage condition is extrapolated between 105-10^7 h. According to its definition, the accelerating factor is 1462 in 100 ℃/100% relative humidity （RH） stress condition, and 25 ℃/25% RH stress con- dition. Finally, the degradation causes of performance parameters of the test samples are analyzed. The findings can provide certain references for the storage reliability of domestic transistors.     

晶体管加速寿命研究

Choosing small and medium power switching transistors of the NPN type in a 3DK set as the study object,the test of accelerating life is conducted in constant temperature and humidity,and then the data are statistically analyzed with software developed by ourselves.According to degradations of such sensitive parameters as the reverse leakage current of transistors,the lifetime order of transistors is about more than 10~4 at 100℃and 100% relative humidity(RH) conditions.By corrosion fracture of transistor outer leads and other failure modes,with the failure truncated testing,the average lifetime rank of transistors in different distributions is extrapolated about 10~3. Failure mechanism analyses of degradation of electrical parameters,outer lead fracture and other reasons that affect transistor lifetime are conducted.The findings show that the impact of external stress of outer leads on transistor reliability is more serious than that of parameter degradation.