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延时电路在高温湿气环境中的腐蚀行为与机理研究 被引量:3
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作者 魏小琴 张伦武 +3 位作者 肖勇 王艳艳 赵方超 王峙卫 《表面技术》 EI CAS CSCD 北大核心 2018年第7期197-202,共6页
目的提高延时电路的贮存环境适应性。方法在80℃、90%RH的湿热条件下,开展延时电路实验室加速老化试验,分别在老化0、97、133 d时取样,检测电性能,分析电路外表面腐蚀损伤特征,测试内部缺陷和多余物,检查腔体密封性,定位失效部位,观测... 目的提高延时电路的贮存环境适应性。方法在80℃、90%RH的湿热条件下,开展延时电路实验室加速老化试验,分别在老化0、97、133 d时取样,检测电性能,分析电路外表面腐蚀损伤特征,测试内部缺陷和多余物,检查腔体密封性,定位失效部位,观测内部芯片腐蚀损伤特征,检测腐蚀产物,分析高温湿气对延时电路外引线-玻璃界面密封性失效与可伐合金基体腐蚀的作用机制。结果湿热老化133 d时,延时电路输出端3无输出波形。随湿热老化时间的延长,外引线-玻璃界面缝隙腐蚀程度逐渐加深,氦漏率单调上升,壳体密封性逐渐降低乃至失效。外界湿气进入延时电路内部,整个老化周期内部芯片无缺陷,但133 d时电路内腔出现多余物,位于第14外引脚引线柱边缘处,也是导通测试定位的失效点。该引线柱的可伐合金基体与其上的镀金层在高温湿气的作用下,由于电位差形成腐蚀电池,可伐合金作为阴极与湿气和氧发生电化学腐蚀,生成腐蚀产物并覆盖于镀金表面,导致第14外引脚与其上的金键合丝之间开路,延时电路失效。结论降低延时电路贮存环境湿度,同时改进生产工艺,在金属-玻璃封接界面形成一层厚度适当的致密氧化膜过渡层,可延缓湿气进入电路内部。增大可伐合金基体镀金层或镀镍层厚度,可减小基体发生电化学腐蚀几率,提高延时电路贮存环境适应性。 展开更多
关键词 可伐合金 延时电路 高温湿气环境 加速老化试验 腐蚀行为 腐蚀机理
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湿气环境中抗硫钢的元素硫腐蚀特征及腐蚀机理 被引量:5
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作者 刘毅超 钟显康 扈俊颖 《中国腐蚀与防护学报》 CAS CSCD 北大核心 2022年第3期369-377,共9页
探究了CO_(2)湿气环境中P110SS抗硫钢在不同温湿度下的S腐蚀特征及腐蚀机理。采用X射线光电子能谱(XPS)和扫描电子显微镜(SEM),对P110SS钢表面腐蚀产物膜的化学组成、微观形貌及厚度及去除腐蚀产物后基体的微观形貌进行了表征。结果表明... 探究了CO_(2)湿气环境中P110SS抗硫钢在不同温湿度下的S腐蚀特征及腐蚀机理。采用X射线光电子能谱(XPS)和扫描电子显微镜(SEM),对P110SS钢表面腐蚀产物膜的化学组成、微观形貌及厚度及去除腐蚀产物后基体的微观形貌进行了表征。结果表明:在60℃、相对湿度为30%的条件下,S不会参与腐蚀反应,但腐蚀环境中的Cl-和CO_(2)会导致抗硫钢发生局部腐蚀;当相对湿度升高至60%和90%时,S参与了腐蚀的阴极反应,生成FeS,并导致抗硫钢发生全面腐蚀。在80℃、相对湿度为30%的条件下,S也参与腐蚀的阴极反应,并导致抗硫钢发生了局部腐蚀;当相对湿度为60%和90%时,S会发生水解反应,产生H_(2)S和H_(2)SO_(4),使抗硫钢发生严重的全面腐蚀。另外,腐蚀产物膜的厚度随湿度的升高而增加,致密度随反应温度的升高而降低。研究结果能为抗硫钢的S腐蚀控制提供参考。 展开更多
关键词 湿气环境 S腐蚀 P110SS 腐蚀特征 腐蚀机理
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环境湿气对BGA可靠性影响案例分析
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作者 阮熙仑 郭辉 《电子产品可靠性与环境试验》 2018年第2期37-40,共4页
作为PCBA中最重要的封装元件之一,BGA器件对于保障PCBA的质量与可靠性具有重要的作用。因此,分析BGA器件的失效现象并制定相应的解决措施具有重要的意义。利用X-Ray检测、染色渗透检测、金相切片分析和声学扫描分析等方法对BGA器件的功... 作为PCBA中最重要的封装元件之一,BGA器件对于保障PCBA的质量与可靠性具有重要的作用。因此,分析BGA器件的失效现象并制定相应的解决措施具有重要的意义。利用X-Ray检测、染色渗透检测、金相切片分析和声学扫描分析等方法对BGA器件的功能失效现象进行了详细的分析,找到了器件失效的原因,对于避免类似失效现象再次发生,保证器件的可靠性具有一定的意义。 展开更多
关键词 环境湿气 失效分析 金相切片 声学扫描
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Extreme Adaptation to Extreme Environments in Hot Dry, Hot Sub-humid and Hot Humid Climates in Mexico
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作者 Luis Gabriel Gomez-Azpeitia Gonzalo Bojorquez-Morales +3 位作者 Raul Pavel Ruiz Irene Marincic Eduardo Gonzalez Adalberto Tejeda 《Journal of Civil Engineering and Architecture》 2014年第8期929-942,共14页
The paper discusses the results of a field study carried out in four cities in Mexico: Hermosillo, Mexicali, Merida and Colima, during the warmest seasons of 2006-2007. The survey is according to the adaptive approac... The paper discusses the results of a field study carried out in four cities in Mexico: Hermosillo, Mexicali, Merida and Colima, during the warmest seasons of 2006-2007. The survey is according to the adaptive approach of thermal comfort. The cities' climates are hot dry, hot sub-humid and hot humid. The respondents were inhabitants of low cost housings without air conditioning. The research was performed during warm seasons and according to ISO 10551. The measurements were processed by the common method of linear regression and also by alternative methods, useful for asymmetric climates. Individuals declared comfort at very high temperatures, either high or low humidity, therefore, the resulting neutral temperatures are higher than 30 ℃, except in Colima (28.8 ℃). The upper limits of comfort ranges achieved temperatures up to 35 ℃. The results suggest how great is the capacity of humans to adapt to conditions as extreme as those measured in the study. 展开更多
关键词 ACCLIMATION thermal comfort adaptive approach field studies
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Analysis of long-term variations of fog and haze in China in recent 50 years and their relations with atmospheric humidity 被引量:81
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作者 DING YiHui LIU YanJu 《Science China Earth Sciences》 SCIE EI CAS 2014年第1期36-46,共11页
Our analysis of fog and haze observations from the surface weather stations in China in recent 50 years (from 196l to 2011) shows that the number of fog days has experienced two-stage variations, with an increasing ... Our analysis of fog and haze observations from the surface weather stations in China in recent 50 years (from 196l to 2011) shows that the number of fog days has experienced two-stage variations, with an increasing trend before 1980 and a decreasing trend after 1990. Especially, an obvious decreasing trend after 1990 can be clearly seen, which is consistent with the decreas- ing trend of the surface relative humidity. However, the number of haze days has demonstrated an increasing trend. As such, the role of reduction of atmospheric relative humidity in the transition process from fog into haze has been further investigated. It is estimated that the mean relative humidity of haze days is about 69%, lower than previously estimated, which implies that it is more difficult for the haze particles to transform into fog drops. This is possibly one of the major environmental factors leading to the reduction of number of fog days. The threshold of the relative humidity for transition from fog into haze is about 82%, also lower than previously estimated. Thus, the reduction of the surface relative humidity in China mainly due to the in- crease of the surface temperature and the saturation specific humidity may exert an obvious impact on the environmental con- ditions for the formations of fog and haze. In addition, our investigation of the relationship between haze and visibility reveals that with the increase of haze days, the visibility has declined markedly. Since 1961, the mean visibility has dropped from 4-10 to 2-4 kin, about a half of the previous horizontal distance of visibility. 展开更多
关键词 fog and haze VISIBILITY relative humidity transition from fog into haze
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Assessment of Climate Suitability for Human Settlements in Tibet,China 被引量:3
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作者 LIN Yumei ZHU Fuxin +1 位作者 LI Wenjun LIU Xiaona 《Journal of Resources and Ecology》 CSCD 2022年第5期880-887,共8页
Climate is an important factor that affects the livability of a region.The climate suitability of a region’s environment for human settlement profoundly affects the regional socio-economic development and the populat... Climate is an important factor that affects the livability of a region.The climate suitability of a region’s environment for human settlement profoundly affects the regional socio-economic development and the population distribution.Tibet is an area that is sensitive to climate change.Given the impact of global climate change,the climate suitability of Tibet has undergone significant changes.In this study,the temperature humidity index(THI)values for Tibet were calculated,and the relationships between the population distribution and the THI were analyzed quantitatively.In this way,the zoning standards for climate suitability in Tibet were determined such that the climate suitability could be evaluated.The results show that the average annual temperature in the southeast of Tibet,where the population was densely distributed,was relatively high.The mean annual relative humidity showed a trend of gradually decreasing from south to north.Regions with a suitable climate,including the high suitability areas(HSAs),the moderately suitable areas(MSAs)and the low suitability areas(LSAs),accounted for only 7.90%of the total area but accommodated over 40%of the total population.The critically suitable areas(CSAs)accounted for 37.81%of the land area and 48.24%of the total population.Non-suitable areas(NSAs)were widely distributed in Tibet and accounted for 54.29%of the total area and 11.33%of the total population.The results of this study may provide a reference for guiding the reasonable distribution of population and promoting the optimization of the spatial planning in Tibet. 展开更多
关键词 climate suitability temperature-humidity index human settlements TIBET
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The effect of air exposure on device performance of flexible C8-BTBT organic thin-film transistors with hygroscopic insulators 被引量:2
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作者 Pengshan Xie Tianjiao Liu +4 位作者 Pei He Guozhang Dai Jie Jiang Jia Sun Junliang Yang 《Science China Materials》 SCIE EI CSCD 2020年第12期2551-2559,共9页
Organic thin film transistors(OTFTs)are normally sensitive to ambient conditions and show performance degradation in air.On the contrary,the performance of flexible 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene(C8... Organic thin film transistors(OTFTs)are normally sensitive to ambient conditions and show performance degradation in air.On the contrary,the performance of flexible 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene(C8-BTBT)OTFTs using cross-linked polymer layer,poly(4-vinyl-phenol)-4,4’-(hexafluoroisopropylidene)diphthalic anhydride(PVP-HDA),as the dielectric layer can be improved in air conditions with 40%relative humidity.Under soaking in air with 40%relative humidity,the electrical behavior,surface morphology,and contact angle of the flexible C8-BTBT OTFTs using PVP-HAD as dielectric layer with three different thicknesses were investigated.It is found that,when the devices with 375 nm-thick PVP-HDA films are placed in 40%relative humidity air conditions for 6 h,the corrected average mobility(μ)can increase from 3.2 to 5.1 cm^2 V^-1 s^-1.Furthermore,the average threshold voltage(Vth)changes from-12.4 to-9.3 V while keeping a constant ratio of I on/Ioff=10^4.These results indicate that the flexible C8-BTBT OTFTs with PVP-HDA dielectric layer exhibit interesting application prospects. 展开更多
关键词 flexible electronics C8-BTBT OTFTs PVP-HDA HYGROSCOPICITY air stability
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