Pub Date : 2011-10-06DOI: 10.1109/HOLM.2011.6034777
Peng Zhang, Y. Lau, W. Tang, M. Gomez, D. French, J. Zier, R. Gilgenbach
Contact resistance is important to integrated circuits and thin film devices, carbon nanotube based cathodes and interconnects, field emitters, wire-array z-pinches, metal-insulator-vacuum junctions, and high power microwave sources, etc. In other applications, the electrical contacts are formed by thin film structures of a few microns thickness, such as in micro-electromechanical system (MEMS) relays and microconnector systems. This paper summarizes the recent modeling efforts at the University of Michigan, addressing the effect of dissimilar materials and of finite dimensions on the contact resistance of both bulk contacts and thin film contacts. The Cartesian and cylindrical geometries are analyzed. Accurate analytical scaling laws are constructed for the contact resistance of both bulk contacts and thin film contacts over a large range of aspect ratios and resistivity ratios. These were validated against known limiting cases and spot-checks with numerical simulations.
{"title":"Contact Resistance with Dissimilar Materials: Bulk Contacts and Thin Film Contacts","authors":"Peng Zhang, Y. Lau, W. Tang, M. Gomez, D. French, J. Zier, R. Gilgenbach","doi":"10.1109/HOLM.2011.6034777","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034777","url":null,"abstract":"Contact resistance is important to integrated circuits and thin film devices, carbon nanotube based cathodes and interconnects, field emitters, wire-array z-pinches, metal-insulator-vacuum junctions, and high power microwave sources, etc. In other applications, the electrical contacts are formed by thin film structures of a few microns thickness, such as in micro-electromechanical system (MEMS) relays and microconnector systems. This paper summarizes the recent modeling efforts at the University of Michigan, addressing the effect of dissimilar materials and of finite dimensions on the contact resistance of both bulk contacts and thin film contacts. The Cartesian and cylindrical geometries are analyzed. Accurate analytical scaling laws are constructed for the contact resistance of both bulk contacts and thin film contacts over a large range of aspect ratios and resistivity ratios. These were validated against known limiting cases and spot-checks with numerical simulations.","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"198 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":"133870135","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.2011.6034781
R. Malucci
Greenwood's approach to interaction between current carrying contact spots was used to analyze the degradation of single spots. The degradation is assumed to occur from electro-migration which causes a non-uniform increase in the effective resistivity across each contact spot. The latter results were used to evaluate the degradation of a simulated multi-spot interface to demonstrate the cascade failure mode believed to occur in power contacts. In addition, factors such as spot size, position and interaction with nearby spots were assessed in their impact on current density variation across the contact region.
{"title":"The Effects of Current Density Variations in Power Contact Interfaces","authors":"R. Malucci","doi":"10.1109/HOLM.2011.6034781","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034781","url":null,"abstract":"Greenwood's approach to interaction between current carrying contact spots was used to analyze the degradation of single spots. The degradation is assumed to occur from electro-migration which causes a non-uniform increase in the effective resistivity across each contact spot. The latter results were used to evaluate the degradation of a simulated multi-spot interface to demonstrate the cascade failure mode believed to occur in power contacts. In addition, factors such as spot size, position and interaction with nearby spots were assessed in their impact on current density variation across the contact region.","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"24 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":"126953061","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.2011.6034814
F. Ostendorf, T. Wielsch, M. Reiniger
Electroplated tin surfaces are one of the most used and wide spread contact surfaces for connectors in fields of electrical connectivity and applications. The current study focused on a detailed characterisation of tribological and electrical properties of different electroplated matt and bright tin surfaces to get a deeper insight to the relation of wear failure mechanisms and electrical contact resistance characteristics. The experiments were carried out with a special in-house developed tribometer with variable sliding path, dynamically changeable normal loads and sliding velocities to simulate the sliding motion of connector contacts during insertion and withdrawal. This setup can not only record the occurring friction forces, but has also the capability to measure the contact resistance during every sliding cycle. In a first step we have determined the influence of normal load, sliding distance and velocity on the contact resistance and the friction force by means of a statistical DoE analysis. Hereby we found, that from an electrical point of view matt tin surfaces have a more stable contact resistance characteristic than bright tin surfaces, but under pure tribological aspects bright tin surfaces excel by initially lower friction force values. In the second step the wear tracks were investigated by means of SEM, EDX and optical 3D-microscopy to clarify which major wear failure mechanisms cause the observed different electrical and tribological properties. Within these investigations we were able to identify tin surface specific wear failure mechanisms which can be brought into correlation to the findings of the DoE analysis and can explain the observed contact resistance characteristics.
{"title":"There is Tin and there is Tin - Characterisation of Tribological and Electrical Properties of Electroplated Tin Surfaces","authors":"F. Ostendorf, T. Wielsch, M. Reiniger","doi":"10.1109/HOLM.2011.6034814","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034814","url":null,"abstract":"Electroplated tin surfaces are one of the most used and wide spread contact surfaces for connectors in fields of electrical connectivity and applications. The current study focused on a detailed characterisation of tribological and electrical properties of different electroplated matt and bright tin surfaces to get a deeper insight to the relation of wear failure mechanisms and electrical contact resistance characteristics. The experiments were carried out with a special in-house developed tribometer with variable sliding path, dynamically changeable normal loads and sliding velocities to simulate the sliding motion of connector contacts during insertion and withdrawal. This setup can not only record the occurring friction forces, but has also the capability to measure the contact resistance during every sliding cycle. In a first step we have determined the influence of normal load, sliding distance and velocity on the contact resistance and the friction force by means of a statistical DoE analysis. Hereby we found, that from an electrical point of view matt tin surfaces have a more stable contact resistance characteristic than bright tin surfaces, but under pure tribological aspects bright tin surfaces excel by initially lower friction force values. In the second step the wear tracks were investigated by means of SEM, EDX and optical 3D-microscopy to clarify which major wear failure mechanisms cause the observed different electrical and tribological properties. Within these investigations we were able to identify tin surface specific wear failure mechanisms which can be brought into correlation to the findings of the DoE analysis and can explain the observed contact resistance characteristics.","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"287 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":"116236993","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.2011.6034811
Bo Wang, Guangning Wu, Lijun Zhou, Guoqiang Gao, Wangang Wang, Donglai Liu, Dajian Li, Tianzhi Li
Sliding electrical contact is the main process for locomotive to carry current in electrical railways. The relative sliding velocity between pantograph and cantenary increases with the speeding up of locomotive, However¿Cthe adhesiveness between pantograph and cantenary decreases. Meanwhile, the contact status of pantograph and catenary get worse. Pantograph arc occurred frequently under these conditions. Pantograph arcing eroded pantograph slider and contact wire seriously. That affected the contacting morphology between pantograph and contact wire severely. The erosion degree is mainly determined by arcing energy. In this paper, the pantograph arc's electrical parameters such as voltage, current and energy were tested under different load by Pantograph-Catenary Arcing Experiment System (PCAES). Relationship between arc's average duration and traction current was analyzed. Influence of load power factor was studied too. Relationship between arc energy and load character was studied at last. It is demonstrated that arc's average duration becomes longer with the increasing of traction current. Arc duration under inductive load is longer than resistive load. Arc energy decreases when load power factor increase.
{"title":"Pantograph Arc's Energy Characters under Various Load","authors":"Bo Wang, Guangning Wu, Lijun Zhou, Guoqiang Gao, Wangang Wang, Donglai Liu, Dajian Li, Tianzhi Li","doi":"10.1109/HOLM.2011.6034811","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034811","url":null,"abstract":"Sliding electrical contact is the main process for locomotive to carry current in electrical railways. The relative sliding velocity between pantograph and cantenary increases with the speeding up of locomotive, However¿Cthe adhesiveness between pantograph and cantenary decreases. Meanwhile, the contact status of pantograph and catenary get worse. Pantograph arc occurred frequently under these conditions. Pantograph arcing eroded pantograph slider and contact wire seriously. That affected the contacting morphology between pantograph and contact wire severely. The erosion degree is mainly determined by arcing energy. In this paper, the pantograph arc's electrical parameters such as voltage, current and energy were tested under different load by Pantograph-Catenary Arcing Experiment System (PCAES). Relationship between arc's average duration and traction current was analyzed. Influence of load power factor was studied too. Relationship between arc energy and load character was studied at last. It is demonstrated that arc's average duration becomes longer with the increasing of traction current. Arc duration under inductive load is longer than resistive load. Arc energy decreases when load power factor increase.","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":"123555661","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.2011.6034784
S. Noel, D. Alamarguy, S. Correia, P. Laurat
Fretting remains a major cause of connector failure and can impair reliability in complex systems. Oxidizable metals such as tin, copper and nickel are particularly prone to fretting degradation. We report here the first results of an investigation on fretting of nickel contacts with two types of deposits. Sulfate nickel layers are electrodeposited in different conditions and show very different behaviours during fretting tests. The characteristics of the layers are analyzed and show different compositions and microstructures. The compositions are measured by X-Ray Photoelectron Spectroscopy (XPS) which allows determining the chemical nature of the compounds formed during exposure to air. Topography is measured by AFM and the roughness and grain characteristics are assessed. Electrical properties at the micro/nanoscale are measured with the CP-AFM technique. Various loads are applied to the cantilever beam; the electrical characterization is performed versus the load. The results of fretting experiments are analyzed in terms of fretting regimes. The fretting regimes occurring during the test of the matte layers involve partial slip which delays the occurrence of contact resistance (Rc) increase. Gross slip in the interface is shown to create very poorly conducting wear debris leading to drastic increase of Rc. This study is part of a larger one aiming at tailoring coatings allowing the best tribological and electrical behaviors during fretting of nickel contacts.
{"title":"Fretting Behavior of Nickel Coatings for Electrical Contact Applications","authors":"S. Noel, D. Alamarguy, S. Correia, P. Laurat","doi":"10.1109/HOLM.2011.6034784","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034784","url":null,"abstract":"Fretting remains a major cause of connector failure and can impair reliability in complex systems. Oxidizable metals such as tin, copper and nickel are particularly prone to fretting degradation. We report here the first results of an investigation on fretting of nickel contacts with two types of deposits. Sulfate nickel layers are electrodeposited in different conditions and show very different behaviours during fretting tests. The characteristics of the layers are analyzed and show different compositions and microstructures. The compositions are measured by X-Ray Photoelectron Spectroscopy (XPS) which allows determining the chemical nature of the compounds formed during exposure to air. Topography is measured by AFM and the roughness and grain characteristics are assessed. Electrical properties at the micro/nanoscale are measured with the CP-AFM technique. Various loads are applied to the cantilever beam; the electrical characterization is performed versus the load. The results of fretting experiments are analyzed in terms of fretting regimes. The fretting regimes occurring during the test of the matte layers involve partial slip which delays the occurrence of contact resistance (Rc) increase. Gross slip in the interface is shown to create very poorly conducting wear debris leading to drastic increase of Rc. This study is part of a larger one aiming at tailoring coatings allowing the best tribological and electrical behaviors during fretting of nickel contacts.","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":"122316887","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.2011.6034793
Michael Rabla, P. Schweitzer, E. Tisserand
Abstract-The object of this paper is to present a method to design and to improve arc fault detection algorithm using FPGA devices. When designing an arc fault detection prototype, criteria such as detection reliability, detection speed and silicon occupation must be extracted to compare detection algorithm performances. We have developed a device which can execute and test the performances of algorithms with differents kind of power sources (AC and DC for domestic and aeronautic applications) and any loads. This prototype includes an analog part to carry out line voltage and current measurements (up to 270 V, up to 50 A, up to 1.5 MSPS). The digital part is built with an Altera Cyclone III FPGA circuit. An interface is added to control a contactor which protects the electric line. Algorithm implementation is carry out with VHDL We describe the algorithms in VHDL. The board architecture is characterized by low power consumption, high fonctionality and fast prototyping. Our prototype gives an effective and inexpensive means to design arc fault detection algorithms.
摘要:本文的目的是提出一种利用FPGA器件设计和改进电弧故障检测算法的方法。在设计电弧故障检测原型时，必须提取检测可靠性、检测速度和硅占用量等标准来比较检测算法的性能。我们开发了一种设备，可以在不同类型的电源(家用和航空应用的交流和直流)和任何负载下执行和测试算法的性能。该原型包括一个模拟部分，用于进行线路电压和电流测量(最高270 V，最高50 A，最高1.5 MSPS)。数字部分采用Altera Cyclone III FPGA电路构建。增加了一个接口来控制保护电线的接触器。算法的实现是用VHDL语言来实现的。该板结构具有低功耗、高功能和快速成型的特点。我们的原型为设计电弧故障检测算法提供了一种有效而廉价的方法。
{"title":"Method to Design Arc Fault Detection Algorithm Using FPGA","authors":"Michael Rabla, P. Schweitzer, E. Tisserand","doi":"10.1109/HOLM.2011.6034793","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034793","url":null,"abstract":"Abstract-The object of this paper is to present a method to design and to improve arc fault detection algorithm using FPGA devices. When designing an arc fault detection prototype, criteria such as detection reliability, detection speed and silicon occupation must be extracted to compare detection algorithm performances. We have developed a device which can execute and test the performances of algorithms with differents kind of power sources (AC and DC for domestic and aeronautic applications) and any loads. This prototype includes an analog part to carry out line voltage and current measurements (up to 270 V, up to 50 A, up to 1.5 MSPS). The digital part is built with an Altera Cyclone III FPGA circuit. An interface is added to control a contactor which protects the electric line. Algorithm implementation is carry out with VHDL We describe the algorithms in VHDL. The board architecture is characterized by low power consumption, high fonctionality and fast prototyping. Our prototype gives an effective and inexpensive means to design arc fault detection algorithms.","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"18 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":"125076284","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.2011.6034804
C. L. Rodekohr, G. Flowers, M. Bozack, R. Jackson, R. Martens, Z. Zhao, E. R. Crandall, V. Starman, T. Bitner, J. Street
This paper explores the notion that the nucleation and growth of Sn whiskers is motivated by net compressive intrinsic thin film stresses. In this view, a threshold level of stress should exist at which Sn whiskers nucleate; furthermore, whiskering will relieve the compressive stress by a measurable amount. We examine the threshold stress for whisker nucleation and measure the amount of stress relieved during Sn whisker growth on brass substrates. The stress evolution has been evaluated by traditional bent beam analysis via novel machine vision techniques. Whisker nucleation and growth of the Cu-Sn intermetallic layer was observed by FIB sectioning, EDX mapping, and electron microscopy. Results show that the measured stress evolution shows little correlation to whisker nucleation and intermetallic growth. Further, we observe whisker population densities under both compressive and near neutral thin film stress conditions.
{"title":"Correlation of Intrinsic Thin Film Stress Evolution and IMC Growth with Whisker Growth","authors":"C. L. Rodekohr, G. Flowers, M. Bozack, R. Jackson, R. Martens, Z. Zhao, E. R. Crandall, V. Starman, T. Bitner, J. Street","doi":"10.1109/HOLM.2011.6034804","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034804","url":null,"abstract":"This paper explores the notion that the nucleation and growth of Sn whiskers is motivated by net compressive intrinsic thin film stresses. In this view, a threshold level of stress should exist at which Sn whiskers nucleate; furthermore, whiskering will relieve the compressive stress by a measurable amount. We examine the threshold stress for whisker nucleation and measure the amount of stress relieved during Sn whisker growth on brass substrates. The stress evolution has been evaluated by traditional bent beam analysis via novel machine vision techniques. Whisker nucleation and growth of the Cu-Sn intermetallic layer was observed by FIB sectioning, EDX mapping, and electron microscopy. Results show that the measured stress evolution shows little correlation to whisker nucleation and intermetallic growth. Further, we observe whisker population densities under both compressive and near neutral thin film stress conditions.","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"13 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":"117160744","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.2011.6034779
Thomas Øyvang, E. Fjeld, W. Rondeel, S. T. Hagen
An arc fault inside metal enclosed switchgear will cause the pressure to rise and vaporization of electrode material may contribute to the pressure rise. An experimental study of high current arc erosion on copper electrodes in air has been performed, with an evaluation of fraction lost by gross melting and vaporization. All experiments were performed at NEFI High Voltage Laboratory in Skien, Norway. The measured mass loss from vaporization in our experiments seems to be negligible compared to erosion by gross melting.
{"title":"High Current Arc Erosion on Copper Electrodes in Air","authors":"Thomas Øyvang, E. Fjeld, W. Rondeel, S. T. Hagen","doi":"10.1109/HOLM.2011.6034779","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034779","url":null,"abstract":"An arc fault inside metal enclosed switchgear will cause the pressure to rise and vaporization of electrode material may contribute to the pressure rise. An experimental study of high current arc erosion on copper electrodes in air has been performed, with an evaluation of fraction lost by gross melting and vaporization. All experiments were performed at NEFI High Voltage Laboratory in Skien, Norway. The measured mass loss from vaporization in our experiments seems to be negligible compared to erosion by gross melting.","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"254 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":"115384066","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.2011.6034787
M. Hasegawa, N. Kobayashi, Y. Kohno
Influences of vapors evaporated from an acryl-based non-silicone-type polymeric cured material and conventional silicone-containing polymeric cured materials were evaluated with respect to their effects on contact resistance characteristics of relay contacts at an ambient temperature of 120ºC. More specifically, a commercially-available mechanical relay (AgSnIn contacts) was sealed into a metal can with one of these materials, and placed in a heating chamber to operate, at an operating frequency of 0.5 Hz, 40,000 break operations of an inductive DC 14V-1A, 14V-0.4A, 10V-1A, 5V-1A load currents, or a resistive DC 14V-1A load current. Contact resistance values were measured at every 50 operations. As a result, the relays sealed with the acryl-based non-silicone-type polymeric cured material showed no deterioration in contact resistances, irrespective of the load conditions. On the other hand, the relays sealed with the silicone-containing polymeric cured materials showed more significant deteriorations and fluctuations of the contact resistance characteristics, and certain influences of load conditions on their behaviors were recognized.
{"title":"Contact Resistance Characteristics of Relays Operated in Silicone-Vapor-Containing and Non-Silicone Atmospheres with Different Electrical Load Conditions","authors":"M. Hasegawa, N. Kobayashi, Y. Kohno","doi":"10.1109/HOLM.2011.6034787","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034787","url":null,"abstract":"Influences of vapors evaporated from an acryl-based non-silicone-type polymeric cured material and conventional silicone-containing polymeric cured materials were evaluated with respect to their effects on contact resistance characteristics of relay contacts at an ambient temperature of 120ºC. More specifically, a commercially-available mechanical relay (AgSnIn contacts) was sealed into a metal can with one of these materials, and placed in a heating chamber to operate, at an operating frequency of 0.5 Hz, 40,000 break operations of an inductive DC 14V-1A, 14V-0.4A, 10V-1A, 5V-1A load currents, or a resistive DC 14V-1A load current. Contact resistance values were measured at every 50 operations. As a result, the relays sealed with the acryl-based non-silicone-type polymeric cured material showed no deterioration in contact resistances, irrespective of the load conditions. On the other hand, the relays sealed with the silicone-containing polymeric cured materials showed more significant deteriorations and fluctuations of the contact resistance characteristics, and certain influences of load conditions on their behaviors were recognized.","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"60 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":"115623363","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.2011.6034798
B. Arrazat, P. Duvivier, V. Mandrillon, K. Inal
MEMS ohmic switches have demonstrated interesting performances due in part to their low contact resistance which depends on multiple contributions, one amongst them is the roughness of the contact area. In fact, the contact area is composed by clusters asperities that have different sizes, heights and curvature radii. In this work, we investigate the discrete mechanical deformation of asperities at the nano-scale, in the micro-switch pressure range. Loads from 250 µN up to 2 mN are applied by a nano-indenter with a spherical diamond tip (48.5 µm curvature radius). The resulting contact areas are investigated by AFM topography measurements and treated by digital image processing. As a result for each applied loads, the asperities in plastic deformation mode are sorted and used to determine a value of "surface hardness", coherent with the hardness measured by Berkovich nano-indentation. Finally, the asperities identified in plastic deformation mode are used as inputs for the calculation of the electrical contact resistances of equivalent micro-switches.
{"title":"Discrete Analysis of Gold Surface Asperities Deformation under Spherical Nano-Indentation Towards Electrical Contact Resistance Calculation","authors":"B. Arrazat, P. Duvivier, V. Mandrillon, K. Inal","doi":"10.1109/HOLM.2011.6034798","DOIUrl":"https://doi.org/10.1109/HOLM.2011.6034798","url":null,"abstract":"MEMS ohmic switches have demonstrated interesting performances due in part to their low contact resistance which depends on multiple contributions, one amongst them is the roughness of the contact area. In fact, the contact area is composed by clusters asperities that have different sizes, heights and curvature radii. In this work, we investigate the discrete mechanical deformation of asperities at the nano-scale, in the micro-switch pressure range. Loads from 250 µN up to 2 mN are applied by a nano-indenter with a spherical diamond tip (48.5 µm curvature radius). The resulting contact areas are investigated by AFM topography measurements and treated by digital image processing. As a result for each applied loads, the asperities in plastic deformation mode are sorted and used to determine a value of \"surface hardness\", coherent with the hardness measured by Berkovich nano-indentation. Finally, the asperities identified in plastic deformation mode are used as inputs for the calculation of the electrical contact resistances of equivalent micro-switches.","PeriodicalId":197233,"journal":{"name":"2011 IEEE 57th Holm Conference on Electrical Contacts (Holm)","volume":"46 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":"123448456","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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