Pub Date : 2011-10-06DOI: 10.1109/HOLM.2011.6034788
M. Hasegawa, Keisuke Takahashi
Contact surfaces of mechanical relays and switches are often damaged by arc discharges and/or mechanical wear during switching operations. Conventionally, erosion and transfer characteristics of various contact materials under different load conditions have been mainly studied based on observation and evaluation of contact surfaces after switching operation tests. A further detailed study will become possible if we can observe and numerically evaluate a changing process of surface damages (especially, growth of a crater and/or a pip) on contact surfaces during switching operations. For that purpose, a numerical evaluation system of contact surface damages by way of an optical cross-section method is being constructed. In this paper, Ag contacts were operated to break a DC inductive 14V-2A load current for 50,000 operations, and the contact surface profile (a crater growth process) was numerically evaluated with this system at every 2,000 operations during the switching operations. From the results, certain changes in the cathode surface during the switching operations were able to be observed.
{"title":"Evaluation of Contact Surface Damages with an Optical Cross-Section Method","authors":"M. Hasegawa, Keisuke Takahashi","doi":"10.1109/HOLM.2011.6034788","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034788","url":null,"abstract":"Contact surfaces of mechanical relays and switches are often damaged by arc discharges and/or mechanical wear during switching operations. Conventionally, erosion and transfer characteristics of various contact materials under different load conditions have been mainly studied based on observation and evaluation of contact surfaces after switching operation tests. A further detailed study will become possible if we can observe and numerically evaluate a changing process of surface damages (especially, growth of a crater and/or a pip) on contact surfaces during switching operations. For that purpose, a numerical evaluation system of contact surface damages by way of an optical cross-section method is being constructed. In this paper, Ag contacts were operated to break a DC inductive 14V-2A load current for 50,000 operations, and the contact surface profile (a crater growth process) was numerically evaluated with this system at every 2,000 operations during the switching operations. From the results, certain changes in the cathode surface during the switching operations were able to be observed.","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"82 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120893938","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}
Pub Date : 2011-10-06DOI: 10.1109/HOLM.2011.6034816
Emad Barnawi, K. Sawa, N. Morita, T. Ueno
The performance and reliability of electric motors, electric devices and electrical connections depend on the quality of their materials. One suitable material that is used in the electrical field is silver, because of its high electrical and thermal conductivities. Laboratory studies were made of the effect of temperature changes on a silver coated slip ring and silver graphite brushes. Over the past months, a study have been made on sliding contact using copper ring and natural graphite brush, as compare the copper ring and natural graphite brush, and silver coating ring and silver graphite brush. The contact voltage drop of the copper ring and natural graphite brush increased with the sliding time. However, the contact voltage drop of the silver coated ring and silver graphite brush had little change. In this study we focused on the contact voltage drop, surface film and brush wear at low temperature range -15 to 0 ¿Z under using silver material. The main rule of low current sliding contact should combine high wear resistance, low friction with stable contact voltage drop. To meet this requirement we realized that at 70 wt% silver brush, we could reach to this requirement.
{"title":"The Effect of Various Atmospheric Temperature on the Contact Resistance of Sliding Contact on Silver Coating Slip Ring and Silver Graphite Brush","authors":"Emad Barnawi, K. Sawa, N. Morita, T. Ueno","doi":"10.1109/HOLM.2011.6034816","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034816","url":null,"abstract":"The performance and reliability of electric motors, electric devices and electrical connections depend on the quality of their materials. One suitable material that is used in the electrical field is silver, because of its high electrical and thermal conductivities. Laboratory studies were made of the effect of temperature changes on a silver coated slip ring and silver graphite brushes. Over the past months, a study have been made on sliding contact using copper ring and natural graphite brush, as compare the copper ring and natural graphite brush, and silver coating ring and silver graphite brush. The contact voltage drop of the copper ring and natural graphite brush increased with the sliding time. However, the contact voltage drop of the silver coated ring and silver graphite brush had little change. In this study we focused on the contact voltage drop, surface film and brush wear at low temperature range -15 to 0 ¿Z under using silver material. The main rule of low current sliding contact should combine high wear resistance, low friction with stable contact voltage drop. To meet this requirement we realized that at 70 wt% silver brush, we could reach to this requirement.","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129156313","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}
Pub Date : 2011-10-06DOI: 10.1109/HOLM.2011.6034783
M. Myers, M. Leidner, H. Schmidt
The distribution of individual current paths within a smooth mated surface contact interface results in the areas of highest current density being located at the outer rim of the contact interface. As contact surface roughness increases, the areas of highest current density become more evenly distributed across the contact interface, though still biased toward the outer rim. This effect can be predicted using a 3-dimensional simulation visualization technique and validated experimentally. The tech-nique used for experimental validation involves using thermal camera technology to directly view the thermal response of the material within a contact interface. This is done as a volt-age/current pulse is applied across a plated electrical contact surface mated to an appropriate probe surface. These results are then used to visualize the resulting effect on the current density distribution. This work focuses on the further development and application of the simulation tool and thermal observation tech-nique to be able to better quantify contact interface thermal per-formance with respect to multiple contact parameters.
{"title":"Effect of Contact Parameters on Current Density Distribution in a Contact Interface","authors":"M. Myers, M. Leidner, H. Schmidt","doi":"10.1109/HOLM.2011.6034783","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034783","url":null,"abstract":"The distribution of individual current paths within a smooth mated surface contact interface results in the areas of highest current density being located at the outer rim of the contact interface. As contact surface roughness increases, the areas of highest current density become more evenly distributed across the contact interface, though still biased toward the outer rim. This effect can be predicted using a 3-dimensional simulation visualization technique and validated experimentally. The tech-nique used for experimental validation involves using thermal camera technology to directly view the thermal response of the material within a contact interface. This is done as a volt-age/current pulse is applied across a plated electrical contact surface mated to an appropriate probe surface. These results are then used to visualize the resulting effect on the current density distribution. This work focuses on the further development and application of the simulation tool and thermal observation tech-nique to be able to better quantify contact interface thermal per-formance with respect to multiple contact parameters.","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133225408","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}
Pub Date : 2011-10-06DOI: 10.1109/HOLM.2011.6034802
O. Yaglioglu, R. Martens, A. Cao, Alexander H. Slocum
This paper discusses a method to fabricate contact structures using carbon nanotubes (CNTs) and thin film metal deposition which can be used in applications such as electromechanical probes. We discuss the electrical resistance of CNT structures and electrical enhancement schemes using various metal deposition techniques including sputtering and electroless metal plating. Functional CNT-metal composite contact structures are demonstrated and test results, along with failure mechanisms are discussed. We also discuss factors affecting mechanical compliance, electrical resistance and trade offs between them.
{"title":"Compliant Carbon Nanotube-Metal Contact Structures","authors":"O. Yaglioglu, R. Martens, A. Cao, Alexander H. Slocum","doi":"10.1109/HOLM.2011.6034802","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034802","url":null,"abstract":"This paper discusses a method to fabricate contact structures using carbon nanotubes (CNTs) and thin film metal deposition which can be used in applications such as electromechanical probes. We discuss the electrical resistance of CNT structures and electrical enhancement schemes using various metal deposition techniques including sputtering and electroless metal plating. Functional CNT-metal composite contact structures are demonstrated and test results, along with failure mechanisms are discussed. We also discuss factors affecting mechanical compliance, electrical resistance and trade offs between them.","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"279 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127288521","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}
Pub Date : 2011-10-06DOI: 10.1109/HOLM.2011.6034809
E. Carvou, J. B. Mitchell, N. Ben Jemaa, S. Tian, Z. Belhaja
In order to improve the safety of potentially hazardous situations such as "hot" disconnections of equipment or deteriorated connections, a deeper knowledge of the characteristics of the arcs thus produced and their subsequent damage to contact materials, insulating and wiring, is needed. Numerous studies have been performed on DC arcs as they appear in automotive applications. There is however, a strong need to study arcs in the domain of alternating current, in order to understand their consequences to safety and reliability in domestic applications. The purpose of this study is to extend our knowledge of AC-arc characteristics and consequences (e.g. risk of fire ignition) in order to improve the reliability of security devices such as arc fault circuit interrupters (AFCI). Conditions when arcs could initiate and reinitiate are determined, for a voltage of 220V (50Hz), a current from 1A to 4A, electrodes made with copper or graphite and gaps from 10µm to 1000µm. The conclusion of this work is that arcs produced by graphite electrodes present some characteristics which differ significantly from metallic electrode arcs, especially regarding ignition and re-ignition capability. This behavior should be taken into count for safety considerations.
{"title":"AC Electrical Arcs with Graphite Electrodes","authors":"E. Carvou, J. B. Mitchell, N. Ben Jemaa, S. Tian, Z. Belhaja","doi":"10.1109/HOLM.2011.6034809","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034809","url":null,"abstract":"In order to improve the safety of potentially hazardous situations such as \"hot\" disconnections of equipment or deteriorated connections, a deeper knowledge of the characteristics of the arcs thus produced and their subsequent damage to contact materials, insulating and wiring, is needed. Numerous studies have been performed on DC arcs as they appear in automotive applications. There is however, a strong need to study arcs in the domain of alternating current, in order to understand their consequences to safety and reliability in domestic applications. The purpose of this study is to extend our knowledge of AC-arc characteristics and consequences (e.g. risk of fire ignition) in order to improve the reliability of security devices such as arc fault circuit interrupters (AFCI). Conditions when arcs could initiate and reinitiate are determined, for a voltage of 220V (50Hz), a current from 1A to 4A, electrodes made with copper or graphite and gaps from 10µm to 1000µm. The conclusion of this work is that arcs produced by graphite electrodes present some characteristics which differ significantly from metallic electrode arcs, especially regarding ignition and re-ignition capability. This behavior should be taken into count for safety considerations.","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128994492","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}
Pub Date : 2011-10-06DOI: 10.1109/HOLM.2011.6034822
Yilin Zhou, Yang Lv, Hao Wang
Some organic compounds were proven to exist on the failed electrical contacts on the printed circuit boards in mobile phones. They mixed with both the dust particles and wear debris to cause contact failure under fretting conditions. The bonding function of organic compounds to particles and the influencing factors were analyzed theoretically. As one of the organic compounds found on the contaminated electrical contacts in failed mobile phones, the sodium lactate was chosen as the testing sample of the organics. The effects of sodium lactate on the contacts covered by the typical dust particles (quart, mica) were studied by using a vibration and a fretting simulation respectively. The critical content of sodium lactate to make the particles enter the contact interfaces under fretting was presented. The simulation results suggest that low content of organic compounds can degrade the contact reliability under dust contamination.
{"title":"The Influence of the Organic Compounds on the Contaminated Electrical Contacts","authors":"Yilin Zhou, Yang Lv, Hao Wang","doi":"10.1109/HOLM.2011.6034822","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034822","url":null,"abstract":"Some organic compounds were proven to exist on the failed electrical contacts on the printed circuit boards in mobile phones. They mixed with both the dust particles and wear debris to cause contact failure under fretting conditions. The bonding function of organic compounds to particles and the influencing factors were analyzed theoretically. As one of the organic compounds found on the contaminated electrical contacts in failed mobile phones, the sodium lactate was chosen as the testing sample of the organics. The effects of sodium lactate on the contacts covered by the typical dust particles (quart, mica) were studied by using a vibration and a fretting simulation respectively. The critical content of sodium lactate to make the particles enter the contact interfaces under fretting was presented. The simulation results suggest that low content of organic compounds can degrade the contact reliability under dust contamination.","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115837511","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}
Pub Date : 2011-10-06DOI: 10.1109/HOLM.2011.6034815
Wangang Wang, Anping Dong, Guangning Wu, Guoqiang Gao, Lijun Zhou, Bo Wang, Yi Cui, Donglai Liu, Dajian Li, Tianzhi Li
Perfect sliding contact which requires appropriate contact force between pantograph and contact wire is the key point to guarantee the stability of current collection in locomotive. In order to study on characterization of electrical contact between pantograph and catenary, first, a novel test apparatus of pantograph electrical contact has been developed according to the filed application. The apparatus can simulate laterally (zigzag) movement, vertical vibration and the flexible line contact between pantograph contact strip and contact wire. Then, electrical contact experiments are carried out using this apparatus. Characteristics of static contact resistance under various contact force and traction current are analyzed. A fitted formula for contact resistance is proposed which have two independent variables of contact force and traction current. Possible mechanism for variation of contact resistance is represented in microscopic view of contact surface. It is demonstrated that the static contact resistance decreases with the contact force and traction current increasing.
{"title":"Study on Characterization of Electrical Contact between Pantograph and Catenary","authors":"Wangang Wang, Anping Dong, Guangning Wu, Guoqiang Gao, Lijun Zhou, Bo Wang, Yi Cui, Donglai Liu, Dajian Li, Tianzhi Li","doi":"10.1109/HOLM.2011.6034815","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034815","url":null,"abstract":"Perfect sliding contact which requires appropriate contact force between pantograph and contact wire is the key point to guarantee the stability of current collection in locomotive. In order to study on characterization of electrical contact between pantograph and catenary, first, a novel test apparatus of pantograph electrical contact has been developed according to the filed application. The apparatus can simulate laterally (zigzag) movement, vertical vibration and the flexible line contact between pantograph contact strip and contact wire. Then, electrical contact experiments are carried out using this apparatus. Characteristics of static contact resistance under various contact force and traction current are analyzed. A fitted formula for contact resistance is proposed which have two independent variables of contact force and traction current. Possible mechanism for variation of contact resistance is represented in microscopic view of contact surface. It is demonstrated that the static contact resistance decreases with the contact force and traction current increasing.","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124957231","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}
Pub Date : 2011-10-06DOI: 10.1109/HOLM.2011.6034820
E. R. Crandall, G. Flowers, R. Jackson, P. Lall, M. Bozack
Studies of tin (Sn) whiskers have emphasized the role of compressive stress as the driving force for whisker production, thought to be a necessary condition for Sn whisker growth. The goal of this work is to characterize Sn whisker growth in film systems having measurable net compressive, zero, and tensile intrinsic stress states. The stress states were generated for the case of ~ 0.2 µm sputtered Sn films on Si (which has no interfacial intermetallic) by controlling the background Ar pressure in the magnetron sputtering system, which produces differing bond energies (and stresses) in the resultant films. Verification of the stress states was accomplished by curvature techniques using stylus profilometry and Stoney's equation. The results show that, after three months of incubation at room temperature, high whisker densities are observed under both tensile (12,000 whiskers/cm2) and compressive (16,000 whiskers/cm2) stress conditions, with a minimum whisker density generated in the zero stress (4,000 whiskers/cm2) condition. It is likely that the zero stress condition produced whiskers due to the difficulty in achieving the narrow range (7-9 mTorr) of background pressures necessary to produce the zero stress state. Relative average whisker lengths were 56µm (tensile stress); 4µm (compressive stress); and 1.5µm (zero stress). Subsequent measurements of whisker density (currently at 96 days of incubation) show no reversals/variations in the stress-density relationship.
{"title":"Growth of Sn Whiskers under Net Compressive and Tensile Stress States","authors":"E. R. Crandall, G. Flowers, R. Jackson, P. Lall, M. Bozack","doi":"10.1109/HOLM.2011.6034820","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034820","url":null,"abstract":"Studies of tin (Sn) whiskers have emphasized the role of compressive stress as the driving force for whisker production, thought to be a necessary condition for Sn whisker growth. The goal of this work is to characterize Sn whisker growth in film systems having measurable net compressive, zero, and tensile intrinsic stress states. The stress states were generated for the case of ~ 0.2 µm sputtered Sn films on Si (which has no interfacial intermetallic) by controlling the background Ar pressure in the magnetron sputtering system, which produces differing bond energies (and stresses) in the resultant films. Verification of the stress states was accomplished by curvature techniques using stylus profilometry and Stoney's equation. The results show that, after three months of incubation at room temperature, high whisker densities are observed under both tensile (12,000 whiskers/cm2) and compressive (16,000 whiskers/cm2) stress conditions, with a minimum whisker density generated in the zero stress (4,000 whiskers/cm2) condition. It is likely that the zero stress condition produced whiskers due to the difficulty in achieving the narrow range (7-9 mTorr) of background pressures necessary to produce the zero stress state. Relative average whisker lengths were 56µm (tensile stress); 4µm (compressive stress); and 1.5µm (zero stress). Subsequent measurements of whisker density (currently at 96 days of incubation) show no reversals/variations in the stress-density relationship.","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131244535","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}
Pub Date : 2011-10-06DOI: 10.1109/HOLM.2011.6034780
E. R. Crandall, G. Flowers, P. Lall, M. Bozack
Studies of Sn whiskers under controlled, calibrated humidity conditions shows that the highest whisker densities occur for ~ 85% RH. The whisker specimens were 1500 Å Sn films sputtered under compressive stress conditions on silicon and electrochemically polished brass. Subsequently, the samples were exposed to a series of saturated aqueous salt solutions (which generated calibrated relative humidity values of 33, 43, 70, 76, 85, 98% RH) for ~140 days at room temperature. The Sn on brass case at 85% RH produced 6X greater whisker densities than Sn on brass exposed to pure O2, which in turn produced 9X greater whisker densities than Sn on brass exposed to ambient room temperature/humidity. The longest average whisker lengths (6.1 µm for Sn on brass and 9.3 µm for Sn on Si) occurred for 70% RH on both substrates. Corrosion features were observed on all samples, but the 98% RH samples experienced excessive corrosion. Generally, we find a dramatic increase in whisker density at > 60% RH and especially around 85% RH, in agreement with batch processed whisker experiments involving humidity [H. Reynolds et. al., IEEE Trans. Electron. Packag. Manuf. 33 (2010) and P. Oberndorff et. al., IEEE Electronic Comp. and Tech. Conference (2005) 429].
{"title":"Whisker Growth under Controlled Humidity Exposure","authors":"E. R. Crandall, G. Flowers, P. Lall, M. Bozack","doi":"10.1109/HOLM.2011.6034780","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034780","url":null,"abstract":"Studies of Sn whiskers under controlled, calibrated humidity conditions shows that the highest whisker densities occur for ~ 85% RH. The whisker specimens were 1500 Å Sn films sputtered under compressive stress conditions on silicon and electrochemically polished brass. Subsequently, the samples were exposed to a series of saturated aqueous salt solutions (which generated calibrated relative humidity values of 33, 43, 70, 76, 85, 98% RH) for ~140 days at room temperature. The Sn on brass case at 85% RH produced 6X greater whisker densities than Sn on brass exposed to pure O2, which in turn produced 9X greater whisker densities than Sn on brass exposed to ambient room temperature/humidity. The longest average whisker lengths (6.1 µm for Sn on brass and 9.3 µm for Sn on Si) occurred for 70% RH on both substrates. Corrosion features were observed on all samples, but the 98% RH samples experienced excessive corrosion. Generally, we find a dramatic increase in whisker density at > 60% RH and especially around 85% RH, in agreement with batch processed whisker experiments involving humidity [H. Reynolds et. al., IEEE Trans. Electron. Packag. Manuf. 33 (2010) and P. Oberndorff et. al., IEEE Electronic Comp. and Tech. Conference (2005) 429].","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131336873","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}
Pub Date : 2011-10-06DOI: 10.1109/HOLM.2011.6034789
W. Ren, Songjun Ma, G. Zhai, Huadong Xu
Electric arc erosion during contact break/make cause contact resistance degradation, material transfer, non-closing and non-opening, above failure modes affect relay operation characteristics greatly. A relay model testing device which could simulate relay parameters of: initial contact force between N.C. contacts, contact gap and N.O. over-travel mechanical parameters assembly was used to study arc erosion. During breaking and closing operation, contact resistance, pick-up/release voltage, pick-up/release/arc duration were recorded explicitly during test. The optimal matching mechanical parameters assembly of switch-type contact was determined by test results comprehensively. Therefore the contradiction between reducing arc duration and lower bouncing time was solved in maximum extent. The conclusions drawn in this paper are meaningful for optimization of mechanical parameters of switch-type contact in relay.
{"title":"The effect of mechanical parameters of switch-type contact on relay operation characteristics","authors":"W. Ren, Songjun Ma, G. Zhai, Huadong Xu","doi":"10.1109/HOLM.2011.6034789","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034789","url":null,"abstract":"Electric arc erosion during contact break/make cause contact resistance degradation, material transfer, non-closing and non-opening, above failure modes affect relay operation characteristics greatly. A relay model testing device which could simulate relay parameters of: initial contact force between N.C. contacts, contact gap and N.O. over-travel mechanical parameters assembly was used to study arc erosion. During breaking and closing operation, contact resistance, pick-up/release voltage, pick-up/release/arc duration were recorded explicitly during test. The optimal matching mechanical parameters assembly of switch-type contact was determined by test results comprehensively. Therefore the contradiction between reducing arc duration and lower bouncing time was solved in maximum extent. The conclusions drawn in this paper are meaningful for optimization of mechanical parameters of switch-type contact in relay.","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130975347","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}
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