Pub Date : 2014-05-27DOI: 10.1109/ITHERM.2014.6892276
P. Lall, Vikas Yadav, D. Zhang, J. Suhling, S. Shantaram
Industry migration to leadfree solders has resulted in a proliferation of a wide variety of solder alloy compositions. The most popular amongst these are the Sn-Ag-Cu family of alloys like SAC105 and SAC305. Electronics subjected to shock and vibration may experience strain rates of 1-100 per sec. Electronic product may often be exposed to high temperature during storage, operation and handling in addition to high strain rate transient dynamic loads during drop-impact, shock and vibration. Properties of leadfree solder alloys at high strain rates at low and high temperatures experienced by the solder joint during typical mechanical shock events are scarce. Previous studies have showed the effect of high strain rates and thermal aging on the mechanical properties of leadfree alloys including elastic modulus and the ultimate tensile strength. The ANAND viscoplastic constitutive model has been widely used to describe the inelastic deformation behavior of solders in electronic components. In this study, SAC105 leadfree alloys have been tested at strain rates of 10, 35, 50 and 75 per sec at various operating temperatures of 50°C, 75°C, 100°C and 125°C. Full-field strain in the specimen have been measured using high speed imaging at frame rates up to 75,000 fps in combination with digital image correlation. The cross-head velocity has been measured prior-to, during, and after deformation to ensure the constancy of cross-head velocity. Stress-Strain curves have been plotted over a wide range of strain rates and temperatures. Experimental data for the pristine specimen has been fit to the ANAND's viscoplastic model.
{"title":"High strain rate mechanical properties of SAC105 leadfree alloy at high operating temperatures","authors":"P. Lall, Vikas Yadav, D. Zhang, J. Suhling, S. Shantaram","doi":"10.1109/ITHERM.2014.6892276","DOIUrl":"https://doi.org/10.1109/ITHERM.2014.6892276","url":null,"abstract":"Industry migration to leadfree solders has resulted in a proliferation of a wide variety of solder alloy compositions. The most popular amongst these are the Sn-Ag-Cu family of alloys like SAC105 and SAC305. Electronics subjected to shock and vibration may experience strain rates of 1-100 per sec. Electronic product may often be exposed to high temperature during storage, operation and handling in addition to high strain rate transient dynamic loads during drop-impact, shock and vibration. Properties of leadfree solder alloys at high strain rates at low and high temperatures experienced by the solder joint during typical mechanical shock events are scarce. Previous studies have showed the effect of high strain rates and thermal aging on the mechanical properties of leadfree alloys including elastic modulus and the ultimate tensile strength. The ANAND viscoplastic constitutive model has been widely used to describe the inelastic deformation behavior of solders in electronic components. In this study, SAC105 leadfree alloys have been tested at strain rates of 10, 35, 50 and 75 per sec at various operating temperatures of 50°C, 75°C, 100°C and 125°C. Full-field strain in the specimen have been measured using high speed imaging at frame rates up to 75,000 fps in combination with digital image correlation. The cross-head velocity has been measured prior-to, during, and after deformation to ensure the constancy of cross-head velocity. Stress-Strain curves have been plotted over a wide range of strain rates and temperatures. Experimental data for the pristine specimen has been fit to the ANAND's viscoplastic model.","PeriodicalId":12453,"journal":{"name":"Fourteenth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"21 1","pages":"161-169"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83216124","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 : 2014-05-27DOI: 10.1109/ITHERM.2014.6892432
P. Lall, A. Abrol, Lee Simpson, J. Glover
Micro-electro-mechanical systems (MEMS) devices are used in a variety of applications for sensing acceleration, translation, rotation, pressure and sound in addition to actuation and signal generation. The MEMS devices have been applied to varied fields including healthcare and automotive applications. Data on reliability degradation of MEMS devices in harsh environment applications including combined environments of high temperature exposure, and high-g shock loading is scarce. In this paper, a test vehicle with a MEMS Accelerometers has been studied under high-temperature exposure followed by high-g mechanical shock. Test boards have been designed to assemble all the sensor types. The boards have been subjected to mechanical shocks using the method 2002.5, condition G, under the standard MIL-STD-883H test. Shock pulse amplitudes have been ramped from 500 to 30,000g with pulse duration between 0.1 to 1 millisecond. Full field effect on the components has been extracted using high speed cameras operating at 100,000 fps in conjunction with digital image correlation. The degradation of the MEMS response has been studied using statistical pattern recognition. The failure mechanisms have been characterized. The deterioration of the components has been extracted using non-destructive evaluation with micro-CT scans and X-ray. Further, the degradation of the MEMS response has been studied using statistical pattern recognition. The failure mechanisms have been characterized.
{"title":"Reliability of MEMS devices under multiple environments","authors":"P. Lall, A. Abrol, Lee Simpson, J. Glover","doi":"10.1109/ITHERM.2014.6892432","DOIUrl":"https://doi.org/10.1109/ITHERM.2014.6892432","url":null,"abstract":"Micro-electro-mechanical systems (MEMS) devices are used in a variety of applications for sensing acceleration, translation, rotation, pressure and sound in addition to actuation and signal generation. The MEMS devices have been applied to varied fields including healthcare and automotive applications. Data on reliability degradation of MEMS devices in harsh environment applications including combined environments of high temperature exposure, and high-g shock loading is scarce. In this paper, a test vehicle with a MEMS Accelerometers has been studied under high-temperature exposure followed by high-g mechanical shock. Test boards have been designed to assemble all the sensor types. The boards have been subjected to mechanical shocks using the method 2002.5, condition G, under the standard MIL-STD-883H test. Shock pulse amplitudes have been ramped from 500 to 30,000g with pulse duration between 0.1 to 1 millisecond. Full field effect on the components has been extracted using high speed cameras operating at 100,000 fps in conjunction with digital image correlation. The degradation of the MEMS response has been studied using statistical pattern recognition. The failure mechanisms have been characterized. The deterioration of the components has been extracted using non-destructive evaluation with micro-CT scans and X-ray. Further, the degradation of the MEMS response has been studied using statistical pattern recognition. The failure mechanisms have been characterized.","PeriodicalId":12453,"journal":{"name":"Fourteenth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"89 1 1","pages":"1313-1321"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86465320","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 : 2014-05-27DOI: 10.1109/ITHERM.2014.6892298
Shailesh Malla, Miguel Amaya, H. Moon, S. M. You
The performance of thin-film evaporative cooling for near-junction thermal management was investigated. A liquid delivery system capable of delivering water in small volumes ranging 20~75 nl at frequencies of up to 600 Hz was established. On one side of the silicon chip, a resistive heating layer of 2 mm × 2 mm was fabricated to emulate the high heat flux hot-spot, and on the other side a superhydrophilic nanoporous coating (SHNC) was applied over an area of 10 mm × 10 mm. With the aid of the nanoporous coating, delivered droplets spread into thin films of thicknesses less than 10 μm. With this system, evaporative tests were conducted in ambient in an effort to maximize dryout heat flux and evaporative heat transfer coefficient. During the tests, heat flux at the hot spot was varied to values above 1000 W/cm2. Water was delivered at either given constant frequency (constant mass flow rate) or programmed variations of frequency (variable mass flow rate), for a given nanoliter dose volume. Heat flux and hot spot surface temperatures were recorded upon reaching steady state at each applied heat flux increment. A mixed mode of cooling consisting of simultaneous thin-film evaporation and boiling was observed. Relative to bare silicon surface, dryout heat flux of the SHNC surface was found to increase by ~5 times at 500~600 Hz.
研究了薄膜蒸发冷却在近结热管理中的性能。建立了一种能够以高达600 Hz的频率以20~75 nl的小体积输送水的液体输送系统。在硅片的一侧制作了2 mm × 2 mm的电阻加热层来模拟高热流密度热点，另一侧在10 mm × 10 mm的面积上涂有超亲水性纳米孔涂层(SHNC)。在纳米孔涂层的帮助下，输送的液滴扩散成厚度小于10 μm的薄膜。利用该系统在环境中进行了蒸发试验，以最大限度地提高干热流密度和蒸发换热系数。在试验过程中，热点处的热流密度变化到1000 W/cm2以上。对于给定的纳升剂量体积，水以给定的恒定频率(恒定质量流量)或编程的频率变化(可变质量流量)输送。在每一次热流增量达到稳定状态时，记录热流密度和热点表面温度。同时观察到薄膜蒸发和沸腾的混合冷却模式。在500~600 Hz时，相对于裸硅表面，SHNC表面的干热流密度增加了约5倍。
{"title":"Liquid cooling of a hot spot using a superhydrophilic nanoporous surface","authors":"Shailesh Malla, Miguel Amaya, H. Moon, S. M. You","doi":"10.1109/ITHERM.2014.6892298","DOIUrl":"https://doi.org/10.1109/ITHERM.2014.6892298","url":null,"abstract":"The performance of thin-film evaporative cooling for near-junction thermal management was investigated. A liquid delivery system capable of delivering water in small volumes ranging 20~75 nl at frequencies of up to 600 Hz was established. On one side of the silicon chip, a resistive heating layer of 2 mm × 2 mm was fabricated to emulate the high heat flux hot-spot, and on the other side a superhydrophilic nanoporous coating (SHNC) was applied over an area of 10 mm × 10 mm. With the aid of the nanoporous coating, delivered droplets spread into thin films of thicknesses less than 10 μm. With this system, evaporative tests were conducted in ambient in an effort to maximize dryout heat flux and evaporative heat transfer coefficient. During the tests, heat flux at the hot spot was varied to values above 1000 W/cm2. Water was delivered at either given constant frequency (constant mass flow rate) or programmed variations of frequency (variable mass flow rate), for a given nanoliter dose volume. Heat flux and hot spot surface temperatures were recorded upon reaching steady state at each applied heat flux increment. A mixed mode of cooling consisting of simultaneous thin-film evaporation and boiling was observed. Relative to bare silicon surface, dryout heat flux of the SHNC surface was found to increase by ~5 times at 500~600 Hz.","PeriodicalId":12453,"journal":{"name":"Fourteenth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"36 1","pages":"317-325"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89049232","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 : 2014-05-27DOI: 10.1109/ITHERM.2014.6892294
C. Woodcock, Farzad Houshmand, J. Plawsky, M. Izenson, D. Fogg, R. Hill, Scott Phillips, Y. Peles
A novel approach to embedded electronics cooling with a multi-phase microfluidic heat sink termed the Piranha Pin-Fin (PPF) is presented. Several first-generation PPF devices, as well as plain-channel and solid pin-fin heat sinks, have been fabricated and experimentally tested under single-phase adiabatic conditions. Details of the PPF device geometry and microfabrication process are provided. Plots showing pressure drop and friction factor are also provided. Numerical fluid dynamics modeling has been performed in parallel to the experiments. Modeling data presented includes fractional flow through the pins, predicted pressure losses, fluid streamlines and velocity gradients under several operating conditions. Additionally, micro-particle image velocimetry (μPIV) measurements have been performed. The velocity fields are used to provide further insight into the fluid mechanics within the heat sink as well as to validate the models. Velocity field measurements are included for various operating conditions.
{"title":"Piranha Pin-Fins (PPF): Voracious boiling heat transfer by vapor venting from microchannels - system calibration and single-phase fluid dynamics","authors":"C. Woodcock, Farzad Houshmand, J. Plawsky, M. Izenson, D. Fogg, R. Hill, Scott Phillips, Y. Peles","doi":"10.1109/ITHERM.2014.6892294","DOIUrl":"https://doi.org/10.1109/ITHERM.2014.6892294","url":null,"abstract":"A novel approach to embedded electronics cooling with a multi-phase microfluidic heat sink termed the Piranha Pin-Fin (PPF) is presented. Several first-generation PPF devices, as well as plain-channel and solid pin-fin heat sinks, have been fabricated and experimentally tested under single-phase adiabatic conditions. Details of the PPF device geometry and microfabrication process are provided. Plots showing pressure drop and friction factor are also provided. Numerical fluid dynamics modeling has been performed in parallel to the experiments. Modeling data presented includes fractional flow through the pins, predicted pressure losses, fluid streamlines and velocity gradients under several operating conditions. Additionally, micro-particle image velocimetry (μPIV) measurements have been performed. The velocity fields are used to provide further insight into the fluid mechanics within the heat sink as well as to validate the models. Velocity field measurements are included for various operating conditions.","PeriodicalId":12453,"journal":{"name":"Fourteenth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"134 1","pages":"282-289"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86303743","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 : 2014-05-27DOI: 10.1109/ITHERM.2014.6892439
Koji Takahashi, H. Hayashi
Thermal conductance of an individual multiwalled carbon nanotube was measured as a function of its length. Focused ion beam was used to shorten a 4.8 micrometer-long nanotube to 2.4, 1.2, 0.6, and 0.3-micrometer-long specimens on a hot-film sensor. As the nanotube is shorten, the conductance decreases more than expected by the diffusive thermal conduction theory. We treated two nanotubes of 64nm and 85nm diameters, both of which showed quasi-ballistic phonon transport. This is the first experiment to quantitatively investigate the contribution of phonons with long free paths in multiwalled carbon nanotube. The principle of thermal measurement, amorphous carbon induced by the ion beam, and considerable errors are also explained.
{"title":"Characterization of thermal transport in multiwalled carbon nanotube using FIB irradiation","authors":"Koji Takahashi, H. Hayashi","doi":"10.1109/ITHERM.2014.6892439","DOIUrl":"https://doi.org/10.1109/ITHERM.2014.6892439","url":null,"abstract":"Thermal conductance of an individual multiwalled carbon nanotube was measured as a function of its length. Focused ion beam was used to shorten a 4.8 micrometer-long nanotube to 2.4, 1.2, 0.6, and 0.3-micrometer-long specimens on a hot-film sensor. As the nanotube is shorten, the conductance decreases more than expected by the diffusive thermal conduction theory. We treated two nanotubes of 64nm and 85nm diameters, both of which showed quasi-ballistic phonon transport. This is the first experiment to quantitatively investigate the contribution of phonons with long free paths in multiwalled carbon nanotube. The principle of thermal measurement, amorphous carbon induced by the ion beam, and considerable errors are also explained.","PeriodicalId":12453,"journal":{"name":"Fourteenth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"219 1","pages":"1375-1378"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89119684","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 : 2014-05-27DOI: 10.1109/ITHERM.2014.6892333
R. Zeighami, W. Saunders, Henry Coles, S. Branton
This paper discusses data center scale performance characterization of hybrid liquid-air cooling solutions for a full 42U rack of servers. Using data collected in a production data center at Lawrence Berkeley Laboratories, we interpret the results with a simple three parameter model which allows characterization of the major factors affecting heat recovery efficiency of the system. The model is shown to agree with a broad set of data under a variety of temperature and workload conditions. To our knowledge, this is the first large scale characterization of a hybrid cooling solution's performance in terms relevant to data center operation. We discuss how this method can be extended to other systems for meaningful comparison of solution performance.
{"title":"Thermal performance modeling of hybrid liquid-air cooled servers","authors":"R. Zeighami, W. Saunders, Henry Coles, S. Branton","doi":"10.1109/ITHERM.2014.6892333","DOIUrl":"https://doi.org/10.1109/ITHERM.2014.6892333","url":null,"abstract":"This paper discusses data center scale performance characterization of hybrid liquid-air cooling solutions for a full 42U rack of servers. Using data collected in a production data center at Lawrence Berkeley Laboratories, we interpret the results with a simple three parameter model which allows characterization of the major factors affecting heat recovery efficiency of the system. The model is shown to agree with a broad set of data under a variety of temperature and workload conditions. To our knowledge, this is the first large scale characterization of a hybrid cooling solution's performance in terms relevant to data center operation. We discuss how this method can be extended to other systems for meaningful comparison of solution performance.","PeriodicalId":12453,"journal":{"name":"Fourteenth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"155 1","pages":"583-587"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88996033","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 : 2014-05-27DOI: 10.1109/ITHERM.2014.6892391
V. Jha, T. Hauck
With requirements of higher power density and smaller package size, thermal management of electronic packages has become increasingly challenging since last decade. With several design parameters playing an important role in evaluation of thermal characterization parameter, design approximations can lead to significant error. Substrate design is a critical aspect of the thermal model and the current state-of-the-art varies from approximate copper percentage inclusions to manually building traces to capture important geometrical features. Typically, these methods are prone to approximation errors and are also time consuming for building geometric models. An alternate method proposed is to use direct substrate ECAD integration in the package model that significantly improves the thermal modeling efficiency.
{"title":"Thermal Modeling Improvements using substrate ECAD integration","authors":"V. Jha, T. Hauck","doi":"10.1109/ITHERM.2014.6892391","DOIUrl":"https://doi.org/10.1109/ITHERM.2014.6892391","url":null,"abstract":"With requirements of higher power density and smaller package size, thermal management of electronic packages has become increasingly challenging since last decade. With several design parameters playing an important role in evaluation of thermal characterization parameter, design approximations can lead to significant error. Substrate design is a critical aspect of the thermal model and the current state-of-the-art varies from approximate copper percentage inclusions to manually building traces to capture important geometrical features. Typically, these methods are prone to approximation errors and are also time consuming for building geometric models. An alternate method proposed is to use direct substrate ECAD integration in the package model that significantly improves the thermal modeling efficiency.","PeriodicalId":12453,"journal":{"name":"Fourteenth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"23 1","pages":"1007-1010"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79020709","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 : 2014-05-27DOI: 10.1109/ITHERM.2014.6892412
P. Lall, Shantanu Deshpande, L. Nguyen, M. Murtuza
Wire bonding is predominant mode of interconnect in electronics packaging. Traditionally material used for wire bonding is gold. But industry is slowly replacing gold wire bond by copper-aluminum wire bond because of the lower cost and better mechanical properties than gold, such as high strength, high thermal conductivity etc. Numerous studies have been done to analyze failure mechanism of Cu-Al wire bonds. Cu-Al interface is a predominant location for failure of the wirebond interconnects. In this paper, the use of intermetallic thickness as leading indicator-of-failure for prognostication of remaining useful life for Cu-Al wire bond interconnects has been studied. For analysis, 32 pin chip scale packages were used. Packages were aged isothermally at 200°C and 250°C for 10 days. Packages were withdrawn periodically after 24 hours and its IMC thickness was measured using SEM. The parts have been prognosticated for accrued damage and remaining useful life in current or anticipated future deployment environment. The presented methodology uses evolution of the IMC thickness in conjunction with the Levenberg-Marquardt Algorithm to identify accrued damage in wire bond subjected to thermal aging. The proposed method can be used for equivalency of damage accrued in Cu-Al parts subjected to multiple thermal aging environments.
{"title":"Damage mechanisms in copper-aluminum wirebond under high temperature operation","authors":"P. Lall, Shantanu Deshpande, L. Nguyen, M. Murtuza","doi":"10.1109/ITHERM.2014.6892412","DOIUrl":"https://doi.org/10.1109/ITHERM.2014.6892412","url":null,"abstract":"Wire bonding is predominant mode of interconnect in electronics packaging. Traditionally material used for wire bonding is gold. But industry is slowly replacing gold wire bond by copper-aluminum wire bond because of the lower cost and better mechanical properties than gold, such as high strength, high thermal conductivity etc. Numerous studies have been done to analyze failure mechanism of Cu-Al wire bonds. Cu-Al interface is a predominant location for failure of the wirebond interconnects. In this paper, the use of intermetallic thickness as leading indicator-of-failure for prognostication of remaining useful life for Cu-Al wire bond interconnects has been studied. For analysis, 32 pin chip scale packages were used. Packages were aged isothermally at 200°C and 250°C for 10 days. Packages were withdrawn periodically after 24 hours and its IMC thickness was measured using SEM. The parts have been prognosticated for accrued damage and remaining useful life in current or anticipated future deployment environment. The presented methodology uses evolution of the IMC thickness in conjunction with the Levenberg-Marquardt Algorithm to identify accrued damage in wire bond subjected to thermal aging. The proposed method can be used for equivalency of damage accrued in Cu-Al parts subjected to multiple thermal aging environments.","PeriodicalId":12453,"journal":{"name":"Fourteenth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"66 1","pages":"1171-1178"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77150999","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 : 2014-05-27DOI: 10.1109/ITHERM.2014.6892341
Woosung Park, A. Marconnet, T. Kodama, Joonsuk Park, R. Sinclair, M. Asheghi, K. Goodson
The thermal conductivity of single crystal silicon can be reduced by the introduction of boundaries at the nanoscale. We present the measured thermal conductivity of single crystal silicon nanobeams patterned with a single row of holes at room temperature: the hole diameter and the spacing vary from 100nm to 250nm and from 200 nm to 800nm, respectively. A steady-state four-probe joule heating measurement technique is used to extract the thermal conductivity of the porous silicon nanobeams across a range of pore geometries. The reduction in thermal conductivity owing to the hole boundaries is up to a factor of two.
{"title":"Phonon thermal conduction in periodically porous silicon nanobeams","authors":"Woosung Park, A. Marconnet, T. Kodama, Joonsuk Park, R. Sinclair, M. Asheghi, K. Goodson","doi":"10.1109/ITHERM.2014.6892341","DOIUrl":"https://doi.org/10.1109/ITHERM.2014.6892341","url":null,"abstract":"The thermal conductivity of single crystal silicon can be reduced by the introduction of boundaries at the nanoscale. We present the measured thermal conductivity of single crystal silicon nanobeams patterned with a single row of holes at room temperature: the hole diameter and the spacing vary from 100nm to 250nm and from 200 nm to 800nm, respectively. A steady-state four-probe joule heating measurement technique is used to extract the thermal conductivity of the porous silicon nanobeams across a range of pore geometries. The reduction in thermal conductivity owing to the hole boundaries is up to a factor of two.","PeriodicalId":12453,"journal":{"name":"Fourteenth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"66 1","pages":"637-640"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91393498","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 : 2014-05-27DOI: 10.1109/ITHERM.2014.6892394
J. Marcinichen, S. Szczukiewicz, N. Lamaison, J. Thome
Despite many advances in electronics liquid cooling, air still remains one of the main means of cooling of high heat flux servers of datacenters. Regardless their long history of use, air-cooled blade servers continue to introduce strong nuisances that need to be considered during their implementation and operation, for instance: large energy consumption, difficult to manage the flow of air mastered by fans, and thus non-optimal spatial layout of components within a blade, high cost of air flow equipment, acoustical noise limitations, dust, etc. To overcome such problems, a new essential datacenter infrastructure is required.
{"title":"Towards development of a passive datacenter cooling technology: On-server thermosyphon cooling loop under dynamic workload","authors":"J. Marcinichen, S. Szczukiewicz, N. Lamaison, J. Thome","doi":"10.1109/ITHERM.2014.6892394","DOIUrl":"https://doi.org/10.1109/ITHERM.2014.6892394","url":null,"abstract":"Despite many advances in electronics liquid cooling, air still remains one of the main means of cooling of high heat flux servers of datacenters. Regardless their long history of use, air-cooled blade servers continue to introduce strong nuisances that need to be considered during their implementation and operation, for instance: large energy consumption, difficult to manage the flow of air mastered by fans, and thus non-optimal spatial layout of components within a blade, high cost of air flow equipment, acoustical noise limitations, dust, etc. To overcome such problems, a new essential datacenter infrastructure is required.","PeriodicalId":12453,"journal":{"name":"Fourteenth Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"120 40","pages":"1027-1037"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91403520","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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