Pub Date : 2008-03-16DOI: 10.1109/STHERM.2008.4509370
R. Alley, M. Soto, L. Kwark, P. Crocco, D. Koester
Today's high density processor circuits produce areas of high heat flux which can impose a thermal ceiling on product performance. Chip scale cooling solutions unnecessarily add to the heat sink load by cooling low heat flux areas in addition to the critical localized high heat flux areas (hot spots). In this paper, we demonstrate that embedded thermoelectric cooling (eTEC) technology can be used to significantly lower processor core operating temperatures by focusing the cooling directly on the hottest region. The demonstration vehicle used for this work was the Intel mobile Core 2 Duo, code-named "Merom", the mobile version of Intel's Conroe desktop CPU. Merom utilizes two processor cores that generate localized areas of high heat flux, and as such is ideally suited to demonstrate the benefits of eTEC integration. The Merom chip is available in bare die form, which allowed the eTEC to be integrated onto an external heat spreader and subsequently attached to the CPU. Use of this localized cooling approach and a properly integrated eTEC, provided sustained processor core temperature reductions of between 5degC and 6degC. These cooling results are achieved using a solid-state technology with the associated benefits of manufacturing efficiency, and quiet, reliable operation.
{"title":"Modeling and Validation of On-Die Cooling of Dual-Core CPU using Embedded Thermoelectric Devices","authors":"R. Alley, M. Soto, L. Kwark, P. Crocco, D. Koester","doi":"10.1109/STHERM.2008.4509370","DOIUrl":"https://doi.org/10.1109/STHERM.2008.4509370","url":null,"abstract":"Today's high density processor circuits produce areas of high heat flux which can impose a thermal ceiling on product performance. Chip scale cooling solutions unnecessarily add to the heat sink load by cooling low heat flux areas in addition to the critical localized high heat flux areas (hot spots). In this paper, we demonstrate that embedded thermoelectric cooling (eTEC) technology can be used to significantly lower processor core operating temperatures by focusing the cooling directly on the hottest region. The demonstration vehicle used for this work was the Intel mobile Core 2 Duo, code-named \"Merom\", the mobile version of Intel's Conroe desktop CPU. Merom utilizes two processor cores that generate localized areas of high heat flux, and as such is ideally suited to demonstrate the benefits of eTEC integration. The Merom chip is available in bare die form, which allowed the eTEC to be integrated onto an external heat spreader and subsequently attached to the CPU. Use of this localized cooling approach and a properly integrated eTEC, provided sustained processor core temperature reductions of between 5degC and 6degC. These cooling results are achieved using a solid-state technology with the associated benefits of manufacturing efficiency, and quiet, reliable operation.","PeriodicalId":285718,"journal":{"name":"2008 Twenty-fourth Annual IEEE Semiconductor Thermal Measurement and Management Symposium","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124867060","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 : 2008-03-16DOI: 10.1109/STHERM.2008.4509384
J. Hendrix, D. McCormick, S. Newland, J. Warren
Component densities and high power dissipations have driven conduction cooled communications enclosures near their practical limits. The thermal resistance at the electronics heatsink to chassis interface acts as a major thermal choke point. Better characterizing the heatsink to chassis thermal interface will allow less conservative designs and increased performance. Extensive testing of the thermal resistance at the heatsink and chassis rail interface has been explored at Harris Corporation. The testing and data reduction focused on a method to accurately model the thermal interface. The resulting test method and data reduction technique served to more accurately characterize the module retainer to chassis interface as a parallel thermal resistance path.
{"title":"Thermal Data Reduction for Heatsink to Rack Interfaces","authors":"J. Hendrix, D. McCormick, S. Newland, J. Warren","doi":"10.1109/STHERM.2008.4509384","DOIUrl":"https://doi.org/10.1109/STHERM.2008.4509384","url":null,"abstract":"Component densities and high power dissipations have driven conduction cooled communications enclosures near their practical limits. The thermal resistance at the electronics heatsink to chassis interface acts as a major thermal choke point. Better characterizing the heatsink to chassis thermal interface will allow less conservative designs and increased performance. Extensive testing of the thermal resistance at the heatsink and chassis rail interface has been explored at Harris Corporation. The testing and data reduction focused on a method to accurately model the thermal interface. The resulting test method and data reduction technique served to more accurately characterize the module retainer to chassis interface as a parallel thermal resistance path.","PeriodicalId":285718,"journal":{"name":"2008 Twenty-fourth Annual IEEE Semiconductor Thermal Measurement and Management Symposium","volume":"53 7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126004524","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 : 2008-03-16DOI: 10.1109/STHERM.2008.4509368
J. Yu, W. Oepts, H. Konijn
Increasing requirements of closely packed high power LEDs pose challenges for PC board thermal management. This paper presents a cost-effective thermal solution using FR4 based PCB technology and filled and capped vias. This robust technology enables superior thermal performance on board level for closely packed power LEDs. No solder joint or board level reliability failures were found during a temperature cycling test (TCT) from -40degC to 125degC after 1000 cycles. Moreover no solder joint and board level failure was found after 4000 cycles for open via FR4 when monitoring changes of board thermal resistance. Trade-offs are given for board thermal resistance versus packing density, various board designs, PCB technology, solder joint reliability and PCB board level reliability including open vias and filled and capped vias.
{"title":"PC Board Thermal Management of High Power LEDs","authors":"J. Yu, W. Oepts, H. Konijn","doi":"10.1109/STHERM.2008.4509368","DOIUrl":"https://doi.org/10.1109/STHERM.2008.4509368","url":null,"abstract":"Increasing requirements of closely packed high power LEDs pose challenges for PC board thermal management. This paper presents a cost-effective thermal solution using FR4 based PCB technology and filled and capped vias. This robust technology enables superior thermal performance on board level for closely packed power LEDs. No solder joint or board level reliability failures were found during a temperature cycling test (TCT) from -40degC to 125degC after 1000 cycles. Moreover no solder joint and board level failure was found after 4000 cycles for open via FR4 when monitoring changes of board thermal resistance. Trade-offs are given for board thermal resistance versus packing density, various board designs, PCB technology, solder joint reliability and PCB board level reliability including open vias and filled and capped vias.","PeriodicalId":285718,"journal":{"name":"2008 Twenty-fourth Annual IEEE Semiconductor Thermal Measurement and Management Symposium","volume":"151 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114647914","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 : 2008-03-16DOI: 10.1109/STHERM.2008.4509378
H.K. Ma, B. Hou, J.J. Gao, C. Lin, M. Kou
We investigated a new one-sided actuating piezoelectric micropump combined with a cold plate (OAPCP-micropump) in a liquid cooling system to solve heat dissipation problems and to improve electronic device reliability for a laptop. The OAPCP-micropump, which is composed of a PDMS diaphragm, a 45 mm times 28 mmtimes 4 mm pump chamber with added fins, a rectangular piezoelectric device, and two check valves, can allow a thinner design and drive liquid in one direction. The results show that the shape of the fins has a strong effect on the pressure drops and flow profiles. The fluid in the pump chamber may impinge on the fins and increase the heat dissipation rate due to the oscillation by the actuator. When the fins are shorter than 1.25 mm, they have a negligible effect on the performance of the OAPCP-micropump. In addition, increasing the number of fins from 6 to 12 can enhance the heat dissipation rate but has no influence on the flow rate. The measured maximum flow rate of the OAPCP-micropump is 4.1 ml/s, and its maximum pump head reaches 9807 Pa. In general, the new cooling system with an OAPCP-micropump design shows a stable performance on total thermal resistance due to the high flow rate.
为了解决笔记本电脑的散热问题和提高电子设备的可靠性，我们研究了一种新型的单侧驱动压电微泵与冷板(oapcp -微泵)相结合的液体冷却系统。oapcp微型泵由一个PDMS隔膜、一个45 mm × 28 mm × 4 mm的泵腔(带附加鳍)、一个矩形压电装置和两个止回阀组成，可以实现更薄的设计，并在一个方向上驱动液体。结果表明，翅片的形状对压降和流型有较大的影响。由于致动器的振荡，泵腔内的流体可能冲击鳍片，增加散热率。当翅片长度小于1.25 mm时，对oapcp -微泵性能的影响可以忽略不计。另外，将翅片数量从6片增加到12片可以提高散热率，但对流量没有影响。oapcp -微泵的实测最大流量为4.1 ml/s，最大泵扬程达到9807 Pa。总体而言，采用oapcp -微泵设计的新型冷却系统由于流量大，总热阻性能稳定。
{"title":"Development of One-sided Actuating Piezoelectric Micropump Combined with Cold Plate in a Laptop","authors":"H.K. Ma, B. Hou, J.J. Gao, C. Lin, M. Kou","doi":"10.1109/STHERM.2008.4509378","DOIUrl":"https://doi.org/10.1109/STHERM.2008.4509378","url":null,"abstract":"We investigated a new one-sided actuating piezoelectric micropump combined with a cold plate (OAPCP-micropump) in a liquid cooling system to solve heat dissipation problems and to improve electronic device reliability for a laptop. The OAPCP-micropump, which is composed of a PDMS diaphragm, a 45 mm times 28 mmtimes 4 mm pump chamber with added fins, a rectangular piezoelectric device, and two check valves, can allow a thinner design and drive liquid in one direction. The results show that the shape of the fins has a strong effect on the pressure drops and flow profiles. The fluid in the pump chamber may impinge on the fins and increase the heat dissipation rate due to the oscillation by the actuator. When the fins are shorter than 1.25 mm, they have a negligible effect on the performance of the OAPCP-micropump. In addition, increasing the number of fins from 6 to 12 can enhance the heat dissipation rate but has no influence on the flow rate. The measured maximum flow rate of the OAPCP-micropump is 4.1 ml/s, and its maximum pump head reaches 9807 Pa. In general, the new cooling system with an OAPCP-micropump design shows a stable performance on total thermal resistance due to the high flow rate.","PeriodicalId":285718,"journal":{"name":"2008 Twenty-fourth Annual IEEE Semiconductor Thermal Measurement and Management Symposium","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131284614","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 : 2008-03-16DOI: 10.1109/STHERM.2008.4509387
C. Biber
LED diode performance is a function of the device thermal conditions. The forward voltage and light emission of the LED vary with temperature and current. This paper discusses how to choose the desired operating temperature, by examining the effect of varying the thermal boundary conditions on the light emission. The relationships are important to making design decisions about the LED thermal packaging. A generalized calculation process is given for implementation. An example compares different thermal design constraints.
{"title":"LED Light Emission as a Function of Thermal Conditions","authors":"C. Biber","doi":"10.1109/STHERM.2008.4509387","DOIUrl":"https://doi.org/10.1109/STHERM.2008.4509387","url":null,"abstract":"LED diode performance is a function of the device thermal conditions. The forward voltage and light emission of the LED vary with temperature and current. This paper discusses how to choose the desired operating temperature, by examining the effect of varying the thermal boundary conditions on the light emission. The relationships are important to making design decisions about the LED thermal packaging. A generalized calculation process is given for implementation. An example compares different thermal design constraints.","PeriodicalId":285718,"journal":{"name":"2008 Twenty-fourth Annual IEEE Semiconductor Thermal Measurement and Management Symposium","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133509586","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 : 2008-03-16DOI: 10.1109/STHERM.2008.4509364
D. Schlitz, V. Singhal
A miniature solid-state fan has been developed. The solid-state fan blows air like a typical rotary fan but without any moving parts. It uses the principle of electro- aerodynamic pumping. These fans have been shown to produce a pressure head of up to 42 Pa. Operable fans as small as 1 mm thick have been demonstrated. These fans are intended to provide air flow to cool a 20 Watt chip in an integrated, chip-scale cooling system or to replace the blower in a laptop cooling system.
{"title":"An Electro-Aerodynamic Solid-State Fan and Cooling System","authors":"D. Schlitz, V. Singhal","doi":"10.1109/STHERM.2008.4509364","DOIUrl":"https://doi.org/10.1109/STHERM.2008.4509364","url":null,"abstract":"A miniature solid-state fan has been developed. The solid-state fan blows air like a typical rotary fan but without any moving parts. It uses the principle of electro- aerodynamic pumping. These fans have been shown to produce a pressure head of up to 42 Pa. Operable fans as small as 1 mm thick have been demonstrated. These fans are intended to provide air flow to cool a 20 Watt chip in an integrated, chip-scale cooling system or to replace the blower in a laptop cooling system.","PeriodicalId":285718,"journal":{"name":"2008 Twenty-fourth Annual IEEE Semiconductor Thermal Measurement and Management Symposium","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129670700","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 : 2008-03-16DOI: 10.1109/STHERM.2008.4509374
A. Wojtasik
Output power derating vs. ambient temperature and airflow is a widely used method for defining the thermal limitations of dc-dc power modules. However, this method is not suitable for sealed box applications where the modules are mainly conduction cooled by means of an external heatsink often referred to as a "cold wall" or "cold plate". In this paper a new method for testing and presentation of results for dc-dc modules in such applications is proposed.
{"title":"Testing and Specifying Thermal Performance of DC-DC Power Modules used in Sealed Box Applications","authors":"A. Wojtasik","doi":"10.1109/STHERM.2008.4509374","DOIUrl":"https://doi.org/10.1109/STHERM.2008.4509374","url":null,"abstract":"Output power derating vs. ambient temperature and airflow is a widely used method for defining the thermal limitations of dc-dc power modules. However, this method is not suitable for sealed box applications where the modules are mainly conduction cooled by means of an external heatsink often referred to as a \"cold wall\" or \"cold plate\". In this paper a new method for testing and presentation of results for dc-dc modules in such applications is proposed.","PeriodicalId":285718,"journal":{"name":"2008 Twenty-fourth Annual IEEE Semiconductor Thermal Measurement and Management Symposium","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127217556","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 : 2008-03-16DOI: 10.1109/STHERM.2008.4509357
T. Harirchian, S. Garimella
The local flow boiling heat transfer and pressure drop in microchannel heat sinks are investigated with a dielectric fluid, Fluorinert FC-77. The effect of channel size on flow boiling is studied for mass fluxes ranging from 250 to 1600 kg/m2s for seven different test pieces consisting of parallel microchannels with nominal widths ranging from 100 to 5850 mum, all with a depth of 400 mum. High-speed visualizations are performed simultaneously with the local measurements of the temperature and pressure drop to investigate the flow boiling patterns and the conditions for transition between different regimes. The results of this study show that for microchannels of width 400 mum and greater, the heat transfer coefficients corresponding to a fixed wall heat flux as well as the boiling curves are independent of channel size, and have a weak dependence on channel width for smaller microchannels. This is consistent with the visualizations which show that flow regimes in microchannels of width 400 mum and larger are similar, while those in the 100 mum wide microchannels are distinctly different. Also, unlike the 100 mum wide microchannels, in which bubble nucleation at the walls is suppressed at a relatively low heat flux, nucleate boiling is dominant over a wide range of heat fluxes for microchannels of width 400 mum and larger.
{"title":"Flow Boiling in Silicon Microchannel Heat Sinks","authors":"T. Harirchian, S. Garimella","doi":"10.1109/STHERM.2008.4509357","DOIUrl":"https://doi.org/10.1109/STHERM.2008.4509357","url":null,"abstract":"The local flow boiling heat transfer and pressure drop in microchannel heat sinks are investigated with a dielectric fluid, Fluorinert FC-77. The effect of channel size on flow boiling is studied for mass fluxes ranging from 250 to 1600 kg/m2s for seven different test pieces consisting of parallel microchannels with nominal widths ranging from 100 to 5850 mum, all with a depth of 400 mum. High-speed visualizations are performed simultaneously with the local measurements of the temperature and pressure drop to investigate the flow boiling patterns and the conditions for transition between different regimes. The results of this study show that for microchannels of width 400 mum and greater, the heat transfer coefficients corresponding to a fixed wall heat flux as well as the boiling curves are independent of channel size, and have a weak dependence on channel width for smaller microchannels. This is consistent with the visualizations which show that flow regimes in microchannels of width 400 mum and larger are similar, while those in the 100 mum wide microchannels are distinctly different. Also, unlike the 100 mum wide microchannels, in which bubble nucleation at the walls is suppressed at a relatively low heat flux, nucleate boiling is dominant over a wide range of heat fluxes for microchannels of width 400 mum and larger.","PeriodicalId":285718,"journal":{"name":"2008 Twenty-fourth Annual IEEE Semiconductor Thermal Measurement and Management Symposium","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116321989","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 : 2008-03-16DOI: 10.1109/STHERM.2008.4509376
A. Johnston, D. Stone, Penny Cader
SprayCoolTM developed a hybrid liquid and air-cooled solution for the army's command post platform (CPP), and the result is referred to as CPP-Light (CPP-L). Utilizing COTS network and server gear installed in three sealed transit cases installed in the bed of a HMMWV results in a smaller and lighter configuration of the vehicle utilizing less power. This repackaging of equipment into individual transit cases facilitates the transition between mobile and static operations with mounted and dismounted operation of the transit case equipment. In the case of CPP-L, the objectives of full operation on-the-move and easy transition through the use of transit cases are made possible by the hybrid cooling solution.
{"title":"SprayCool Command Post Platform for Harsh Military Environments","authors":"A. Johnston, D. Stone, Penny Cader","doi":"10.1109/STHERM.2008.4509376","DOIUrl":"https://doi.org/10.1109/STHERM.2008.4509376","url":null,"abstract":"SprayCoolTM developed a hybrid liquid and air-cooled solution for the army's command post platform (CPP), and the result is referred to as CPP-Light (CPP-L). Utilizing COTS network and server gear installed in three sealed transit cases installed in the bed of a HMMWV results in a smaller and lighter configuration of the vehicle utilizing less power. This repackaging of equipment into individual transit cases facilitates the transition between mobile and static operations with mounted and dismounted operation of the transit case equipment. In the case of CPP-L, the objectives of full operation on-the-move and easy transition through the use of transit cases are made possible by the hybrid cooling solution.","PeriodicalId":285718,"journal":{"name":"2008 Twenty-fourth Annual IEEE Semiconductor Thermal Measurement and Management Symposium","volume":"374 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116357042","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 : 2008-03-16DOI: 10.1109/STHERM.2008.4509386
P. Tuma
C2F5C(O)CF(CF3)2, a new Fluoroketone (FK) working fluid with an atmospheric boiling point of 49degC and Global Warming Potential (GWP) ~1, is proposed as an alternative to Perfluorocarbons (PFCs) and hydrofluorocarbons (HFCs) for passive and pumped 2-phase systems. Its thermophysical properties are very similar to those of the PFC C6F14C2F5C(O)CF(CF3)2 exhibits low acute toxicity and bears a recommended 8-hour exposure guideline of 150 ppmv. Pool boiling experiments conducted with a porous metallic boiling enhancement at Patm showed h>8 W/cm2-K at >30 W/cm2. Metal corrosion and elastomer compatibility testing show the material to be very inert. 120 hour thermal stability tests conducted with C2F5C(O)CF(CF3)2 at 230degC in sealed glass ampules with copper and aluminum coupons showed purity changes -0.02%. It will hydrolyze in the presence of a separate water phase and the implications of this incompatibility for water-cooled systems require further investigation.
{"title":"Fluoroketone C2F5C(O)CF(CF3)2 as a Heat Transfer Fluid for Passive and Pumped 2-Phase Applications","authors":"P. Tuma","doi":"10.1109/STHERM.2008.4509386","DOIUrl":"https://doi.org/10.1109/STHERM.2008.4509386","url":null,"abstract":"C<sub>2</sub>F<sub>5</sub>C(O)CF(CF<sub>3</sub>)<sub>2</sub>, a new Fluoroketone (FK) working fluid with an atmospheric boiling point of 49degC and Global Warming Potential (GWP) ~1, is proposed as an alternative to Perfluorocarbons (PFCs) and hydrofluorocarbons (HFCs) for passive and pumped 2-phase systems. Its thermophysical properties are very similar to those of the PFC C<sub>6</sub>F<sub>14</sub>C<sub>2</sub>F<sub>5</sub>C(O)CF(CF<sub>3</sub>)<sub>2</sub> exhibits low acute toxicity and bears a recommended 8-hour exposure guideline of 150 ppmv. Pool boiling experiments conducted with a porous metallic boiling enhancement at P<sub>atm</sub> showed h>8 W/cm<sup>2</sup>-K at >30 W/cm<sup>2</sup>. Metal corrosion and elastomer compatibility testing show the material to be very inert. 120 hour thermal stability tests conducted with C<sub>2</sub>F<sub>5</sub>C(O)CF(CF<sub>3</sub>)<sub>2</sub> at 230degC in sealed glass ampules with copper and aluminum coupons showed purity changes -0.02%. It will hydrolyze in the presence of a separate water phase and the implications of this incompatibility for water-cooled systems require further investigation.","PeriodicalId":285718,"journal":{"name":"2008 Twenty-fourth Annual IEEE Semiconductor Thermal Measurement and Management Symposium","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115857409","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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