{"title":"Influence on Sn whiskering of controlled bismuth additions to sputtered Sn films","authors":"E. K. Snipes, G. Flowers, P. Lall, M. Bozack","doi":"10.1109/HOLM.2015.7355074","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355074","url":null,"abstract":"In 2006, the European Union restricted lead (Pb) to > 0.1% (by weight) in electronics. This caused a renewal of interest in Sn whiskers, as the absence of Pb in Sn films had been known for years to promote Sn whisker growth. The early work on Sn whiskers had suggested that elements other than Pb may suppress whiskers. Bi was chosen as an attractive candidate, as it has similar phase formation behavior to Pb, i.e., low solubility, eutectic formation, and no intermetallic compounds with Sn. In this work, the influence of Bi on Sn whiskering is investigated. Three custom Sn-Bi sputter targets with 0.5%, 1.0%, and 2.0% Bi (by weight) were used to generate ~2000Å sputtered Sn films on Si substrates. The samples were incubated for 77 days. Subsequently, three of the samples were placed in a thermal cycling chamber to accelerate whisker growth, while the others continued to incubate under lab conditions. An expected reduction in Sn whisker density was observed on all samples prior to thermal cycling, with the 0.5% Bi samples generating the highest whisker densities (980 cm-2). A dramatic explosion of whiskering occurred, however, in all the specimens after thermal cycling. The results clearly show that small amounts of Bi dramatically lowers the amount of Sn whiskering, but only under isothermal, room temperature conditions.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115434663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhao-Bin Wang, Shang Shang, Xiaoyi Huang, G. Zhai, Wenhua Chen
{"title":"Research on degradation modeling of pick-up time for aerospace electromagnetic relay in long-term stockpile","authors":"Zhao-Bin Wang, Shang Shang, Xiaoyi Huang, G. Zhai, Wenhua Chen","doi":"10.1109/HOLM.2015.7355094","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355094","url":null,"abstract":"The storage degradation test system for aerospace electromagnetic relay (EMR) is designed, which uses FPGA and ARM SCM architecture as system's hardware core. The degradation data rule of pick-up time parameters for aerospace EMR is tested. And the variation law of pick-up time changing with time is obtained. The change of pick-up time is analyzed and verified, which is mainly caused by reeds reaction occurred relaxation. Then, pick-up time and reed reaction exists the approximate linear relationship was found. So, the pick-up time can characterize the degradation of reed relaxation. The storage degradation model of pick-up time is estimated through regression theory. The research results in this paper provide the necessary theoretical method and basis for studying storage reliability and life prediction of the aerospace EMR.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126182769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Experimental validation of external load effects on micro-contact performance and reliability","authors":"T. Laurvick, R. Coutu","doi":"10.1109/HOLM.2015.7355120","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355120","url":null,"abstract":"This paper presents a follow-on study previously presented at the Holm Conference. In the previous work, it was theorized that micro-switch performance and reliability was directly related to the type of external load that was connected. In particular, unintended capacitive loads may discharge at unpredictable times during switch operation and severely degrade or destroy micro-contact surfaces while properly configured loads may actually enhance performance. The severity of this potential vulnerability can be mitigated by purposely including specific circuit elements in various load configurations. This current study is to experimentally investigate and analyze this phenomenon. Using microelectromechanical systems (MEMS) based devices, we have the ability to efficiently and inexpensively fabricate large numbers of identical micro-contact pairs and then connect them to external loads of interest. Using this approach, it was demonstrated that both performance and reliability can be drastically affected by loading. In all cases tested, series inductance and parallel capacitance resulted in premature failure of the micro-contacts tested. Various protective configurations were also tested and all such devices lasted to the targeted 10M cycles of operation with little sign of imminent failure.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125505974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The influence of switching arcs on contact resistance of Ag/SnO2 materials","authors":"T. Mutzel, R. Niederreuther","doi":"10.1109/HOLM.2015.7355092","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355092","url":null,"abstract":"Silver tin oxide (Ag/SnO2) contact materials are widely used for relays and contactor applications. Device approbation in accordance to standards requires several types of temperature rise test in new and switched conditions. Significant differences in temperature rise after the various switching sequences are experienced. In addition, differences between individual phases of one device - especially in switched condition - are known from test. In this work, the contact resistance evaluation under different load conditions has been studied. Therefore the arcing events at make and break operation during different endurance tests (AC-3 and AC-4) have been analyzed and correlated to the contact resistances at rated current level during temperature rise test. Surface layer changes of contact materials after load are characterized by metallurgical methods. The paper shows the formation of different surface layers as a function of arcing energies during make and break operation. The results demonstrate that make and break arc together are creating the surface layers defining the final contact resistance.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132137118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A multi-variable parametric study on the performance of bolted busbar contacts","authors":"James Gatherer, R. Jackson","doi":"10.1109/HOLM.2015.7355085","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355085","url":null,"abstract":"The reliability of bolted joints is a concern for high-powered devices as the generated heat and thermal expansion could loosen the connections over many actuation cycles. There currently appears to be relatively little information on what material combinations, surface finish, etc. would be beneficial. This work experimentally evaluates the reliability of bolted contacts over 100 cycles and develops theoretical models to predict the relative bolted contact performance. The experimental test arrangement includes eight busbar pairs connected in series, while a power supply cycles current so that the busbars reach a desired temperature rise. A variety of cases are tested that vary the busbar material and thickness, washers, torque, bolt property class, diameter, and head types, in 60 different combinations. Each combination is tested three times, and then the cases are compared to each other using statistical methods. As expected, the electrical and thermal cycling fatigues the bolts, and in some cases the limitations of the joint were exceeded.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128740162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Numerical simulation of arc splitting process in a LV switching device considering thermo-field emission mechanism","authors":"A. Singh, Naim Ahmmed, Manaf Atharparvez","doi":"10.1109/HOLM.2015.7355127","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355127","url":null,"abstract":"The need for simulation of arc dynamics in a low voltage switching device has been widely felt in the industry. The movement of the arc plasma in the 3D model is governed by venting and magneto-hydrodynamic interaction. A Coupled Finite Element Analysis (FEA) and Computational Fluid Dynamics (CFD) solver approach is adopted to enhance the accuracy of the solutions. The Arc root effect is modeled using a thin shell layer having non-linear voltage resistance characteristics. Lookup tables for arc root voltages are created as a function of the surface temperature of electrode and adjacent plasma temperatures considering the thermo-field emission mechanism and are integrated with the global CFD solution. The effect of secondary electron emission has been accounted for. The arc splitting phenomenon is modeled for a single splitter plate and extended for multiple splitter plates. Integrating arc root physics helps in understanding the arc root formation, arc bending and lengthening, and subsequent root movement along the splitter plates. Presence of multiple splitter plates also produces blockage to the gas flow which further modifies the arc parameters. The study helped in understanding the effect of splitter plate configurations on arc behavior.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122441250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Spahr, J. Bonig, T. Glassel, S. Spreng, T. Ebert, J. Franke
{"title":"Explicit FEM analysis of a new contacting method for electronic devices with novel wiring harnesses","authors":"M. Spahr, J. Bonig, T. Glassel, S. Spreng, T. Ebert, J. Franke","doi":"10.1109/HOLM.2015.7355128","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355128","url":null,"abstract":"Through customers' desire for an individualization of vehicles, new electronics-supported functions are continuously being added. The automobile wiring harness must meet these requests without any further increase of weight and volume. The basic trend towards a modular vehicular design, the continually growing complexity of production and assembly processes, supports the use of flexible flat cables (FFCs) in a hybrid wiring system architecture. For an integral approach, it is also important to develop corresponding alternatives for electrically contacting FFCs with the components. To that end, the process-conditional, one-sided accessibility of FFCs represents a particular challenge. Motivated by these challenges, the Institute FAPS has developed an automated assembly system of FFCs and a new concept for a flexible electric contacting system enabling direct electrical contacting of installed FFCs. The scope of this approach is the analysis of the new contacting method by means of an explicit finite element analysis (FEA). For this purpose, a numerical model was developed that enables the simulation and optimization of the contacting process and its important parameters. In a second step, the results of the FEA are validated by respective experiments.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131779755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Meyyappan, A. Mcallister, V. Vasudevan, A. Kurella, B. Pathangey, S. Soni
{"title":"Impact of corrosive environment on contact resistance of infrequently mated connectors","authors":"K. Meyyappan, A. Mcallister, V. Vasudevan, A. Kurella, B. Pathangey, S. Soni","doi":"10.1109/HOLM.2015.7355115","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355115","url":null,"abstract":"Separable connectors are commonly plated with gold for optimum electrical properties. In aggressive environments, gold provides adequate resistance for corrosion of underneath copper. Corrosion resistance has been historically studied by exposing the connectors to a mixture of corrosive gases through a mixed flowing gas (MFG) test. A few studies in the past claimed that contact electrical resistance can stay stable even in unplated samples if micromotion between the interfaces can be eliminated. However, contact force relaxation and micromotion can disturb the mating interface resulting in resistance increases. To understand the interactions between surface finish plating, end usage and micromotion under an aggressive environment, a DOE was planned with linear edge connectors in a MFG chamber. The effect of end usage was addressed through mated and unmated connector samples followed by electrical testing. The impact of mechanical force was studied by controlling the micromotion through a custom vibration fixture that was designed to operate within the MFG chamber. Results from our studies are expected to initiate efforts towards improving existing industry test standards with recommendation to consider the effects of mechanical retention and end usage in addition to plating material and thickness.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115559251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. El Mossouess, Elsa Yee Kin Choi, N. Benjemâa, R. El Abdi, L. Doublet, T. Rodari, E. Carvou
{"title":"Statistical analysis of voltage from constriction to micro-arc values during aging by fretting","authors":"S. El Mossouess, Elsa Yee Kin Choi, N. Benjemâa, R. El Abdi, L. Doublet, T. Rodari, E. Carvou","doi":"10.1109/HOLM.2015.7355113","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355113","url":null,"abstract":"In a previous work we observe that the vibration of contact interfaces is the main cause of contact voltage fluctuations due to the so called fretting corrosion phenomenon. In fact the process of generated particles by mechanical wear produce the increase of contact voltage frequently assimilated as high contact resistance. The main objective of this work is to examine conjointly contact voltage and the occurrence of arcs during the well-known three successive fretting phases. The arc voltage is measured during fretting with set oscilloscopes which plot the arc voltage histograms in real time. So, a histogram is built and arc duration is determined and the position on the track of fretting. We applied a voltage of 16V and a current of 3A. Samples extracted from commercial contact are used and fixed on vibration system (frequency 20Hz and relative displacement of 0.8 mm). The main results show that the arcs are observed during the first and final phase of fretting. We assume that after the initiation period of fretting, the wear is increased and induce the increase of the contact voltage and it reaches few hundred millivolts (melting and fritting voltage) and induce micro-arcs. In the second phase, it seems that number of arcs decreases. Finally in ultimate stage of degradation, intermittent arcing voltage is detected close 12V due to bounce on degraded surface filed wear debris.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"151 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122067436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhiyong Wang, Fengyi Guo, Yanjun Chen, He Wang, Zhiqiang Zheng
{"title":"Research on thermoelectric characteristics and recognition methods of looseness fault in coal-mine bolted cable joint","authors":"Zhiyong Wang, Fengyi Guo, Yanjun Chen, He Wang, Zhiqiang Zheng","doi":"10.1109/HOLM.2015.7355118","DOIUrl":"https://doi.org/10.1109/HOLM.2015.7355118","url":null,"abstract":"The coal-mine bolted cable joints are widely used in electrical connection between the cable and electrical equipment. It's particularly important to recognize timely the electrical connection looseness fault of coal-mine bolted cable joints. Lots of looseness fault experiments of silver-plated copper cable joint under different loosening state, current and load conditions were carried out with self-developed experimental platform. The temperature characteristics, contact voltage and current characteristics of the loosening bolted cable joint under different conditions were studied. A new looseness fault identification method based on current energy entropy and Probabilistic Neural Network (PNN) was proposed. The multi-resolution analysis of current signal was conducted by using wavelet transform and the current energy entropy used as a typical feature parameter of electrical connection looseness fault was extracted. The looseness fault can be identified accurately by putting the current energy entropy into a PNN fault diagnosis model. It showed that the method can identify the electrical connection looseness fault of coal-mine bolted cable joint effectively.","PeriodicalId":448541,"journal":{"name":"2015 IEEE 61st Holm Conference on Electrical Contacts (Holm)","volume":"142 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120939521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}