2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)最新文献

{"title":"Numerical Analysis of Passive Manifold Microchannel Heat Exchanger Enhancements","authors":"Daniel Jovin, Jun Jie., Harrison Hui, K. Ooi","doi":"10.1109/iTherm54085.2022.9899550","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899550","url":null,"abstract":"Three microchannel geometries were numerically studied to investigate its effects on a Manifold Microchannel Heat Exchanger system using a full conjugate heat transfer model. The geometries tested are rectangular microchannels, circular reentrant cavity microchannels and sinusoidal wavy microchannels. The pressure drop and heat transfer coefficient data are presented graphically against Re. Their overall performance is measured using two performance evaluation criteria where considerations of both pressure drop and heat transfer performance are made simultaneously. Insights were then taken from the simulation data for possible geometry optimization to further boost performance.","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127316849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaporative Cooling of High Power Density Motors: Design and Analysis","authors":"Ryan Smith, Amitav Tikadar, Satish Kumar, Y. Joshi","doi":"10.1109/iTherm54085.2022.9899655","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899655","url":null,"abstract":"This study presents the design and thermal analysis of a 25kW high-power-density electric motor prototype. The design employs a capillary flow-assisted evaporative cooling system, resulting in a lightweight and power-dense architecture suitable for high-performance electric automobiles and electric aviation applications. The cooling system proposed in this study significantly reduces motor mass by eliminating the need for an external cooling jacket. This design differs from traditional internally cooled motors since a highly wetting dielectric coolant is used to facilitate evaporation within the stator core windings. Furthermore, in place of the usual slot liner material, wicking structures are used to aid coolant flow into the stator core slots. In this way, two-phase flow can be maintained around the stator windings. Novec-7200 dielectric coolant with a saturation temperature of 76 °C at atmospheric pressure is used as the working fluid within the electric motor. The motor is semi-flooded with coolant; therefore, the end windings are also cooled via evaporation. A thin composite sleeve separating the rotor and stator cores of the electric motor was used to prevent coolant from entering the air gap, thus preventing inefficiencies due to friction against the rotor as well as damage to the permanent magnets.","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"88 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134161281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"TIM Coverage Evaluation for High Performance Computing Application","authors":"Shan Lin, Ken Zhang, V. Lin, David Lai, Y. Wang","doi":"10.1109/iTherm54085.2022.9899667","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899667","url":null,"abstract":"High performance computing (HPC) system are improving computing performance to meet ever-increasing challenge continuously, such as high-end central processing unit (CPU) and server. Regarding this requirement, the high thermal conductivity (High-K) thermal interface material (TIM) which between die top surface and heat spreader in EHS-FCBGA is developed to solve the overheating problem. Although there have been many research on materials with high-K TIM in the recent years, the TIM coverage is also one of the most influential factors in high power requirement. At the beginning of the product life (T0), the silicone-based TIM coverage is usually maintained above 95%, but it always occurs the void or delamination issue after reliability test such as TCT and HTSL test which in turn affects the actual application. In summary, the optimization of TIM coverage evaluation after reliability test is inevitable.For system level cooling, the bulk of the heat is normally dissipated through the top of the package. However, thermal resistance junction-to-case (Theta JC) was usually used to judge the thermal performance of upward heat dissipation for package level, which is not enough to explain the overall thermal behavior from system level. In view of that, the maximum junction temperature (Tj) which contain overall thermal characterization is used to define the limitation of TIM coverage in this research.In this study, we present a method which can define the TIM coverage limitation with thermal design power (TDP) up to 100~500W for EHS-FCBGA in different package size and die/package ratio under air cooling system. The influence of the TIM coverage will be more sensitive since the die/package ratio is lower. In conclusion, Tj will be affected by the external cooling system extremely. Theta JC cannot indicate the overall thermal behavior of the entire system, nor can it be used to define the TIM coverage. While defining the TIM coverage, the quality of the external cooling system should be considered at the same time.","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133461635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pulsating Heat Pipe Fin Plates for Enhancing Natural and Forced Convection Cooling of Electronics: Experimental Campaign","authors":"Gautier Rouaze, J. Marcinichen, J. R. Thome, Kangning Xiong, L. Zhang","doi":"10.1109/iTherm54085.2022.9899676","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899676","url":null,"abstract":"Several recently patented, air-cooled flat plate pulsating heat pipe designs were prototyped and experimentally tested at typical industrial benchmark conditions. Tests were done for both natural and forced convection conditions to air. Two low-Global Warming Potential working fluids were evaluated, R1233zd(E) and R1234ze(E). Local face temperature measurements were taken by infrared camera visualization of the entire surface of the plate, while the base temperatures at the heater were made by thermocouples. The IR temperature maps provided local details of the cooling surface temperature to better understand the pulsating phenomena and better design the PHP for optimized heat transfer. A heat load of 40W was dissipated per cold plate in natural convection (not the maximum) in the current test condition, giving a thermal performance 30 to 40% higher than the tests done for a plain aluminum plate of the same thickness and size at the same base temperature. For forced convection, the thermal resistance was reduced by 35% by the louvered fin PHP compared to the plain plate, and 60% higher heat loads could be transferred at the same base temperature. This technology is targeted for cooling base plates in compact, high-power telecommunication base stations (network offloading via distributed antenna systems and small cells), especially for 5G technologies, for passive and fan-driven operation. A second application is passive cooling of power electronics, such as base plates of wall-mounted, high voltage junction boxes. Completely passive cooling (passive PHP fluid motion and passive convection to the air) can reduce energy consumption without any need of a fan and make the cooling system \"wire-free\" for ease in installation, increased reliability, and reduced maintenance.","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132675838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of Transient Liquid Phase Bonding to Low Temperature Co-fired Ceramic Substrates","authors":"John G. Harris, D. Huitink","doi":"10.1109/iTherm54085.2022.9899666","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899666","url":null,"abstract":"In an effort to capitalize on the high temperature potential of wide band gap semiconductors, this paper implements transient liquid phase sintering bonds on gold low temperature co-fired ceramic conductors. The strength of these bonds is characterized by die shear tests at 260 degrees Celsius. Two sample groups are used to determine the benefit, if any to the inclusion of an electroplated copper layer in the process of copper, silver, tin TLPS bonding on gold LTCC ink. The shear strength and shear modulus of each are reported.","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129536796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Investigation of Adjustable Air Amplifiers as an Alternative to Fans in Data Centre Servers","authors":"Eoin H. Oude Essink, T. Persoons, Gordon O'Brien, S. Alimohammadi","doi":"10.1109/iTherm54085.2022.9899509","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899509","url":null,"abstract":"The following paper is part of a comprehensive study which aims to investigate the potential of a linear air amplifier as an alternative to rotary fans in data centre cooling. This paper aims to expand the understanding of the aerodynamic characteristics of the device as parameters such as nozzle width and diffuser angle are altered, as well as validating a numerical model of the device. A modular testing facility was created to allow the device to be investigated under different conditions. The conditions were then replicated in a numerical model using Ansys Fluent, the results of both the numerical and experimental measurements were compared to determine the validity of the numerical model. The numerical model followed the same trends as the experimental measurements when input pressures, nozzle widths and back pressures were varied. It was found that the numerical model was within ±11% of the experimental data, therefore validating the model.","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130585189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal and Mechanical Lid Design for a Multi-Chip Modular Flip-Chip Package","authors":"J. Shaikh, K. Saha, S. Stoeckl, E. Goh","doi":"10.1109/iTherm54085.2022.9899580","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899580","url":null,"abstract":"The multi-chip modular packages are common in mobility applications, quite larger in size due to having different core components on the same substate. Its large size and mismatch in the coefficient of thermal expansion (CTE) between the die and substrate can lead to warpage of the package which in turn presents a huge reliability concern for modular packages. There are several warpage mitigation solutions available which tries to solve the warpage problem: namely, lidded package, stiffeners, core substrate etc. Due to lower space availability in modular packages, lidded package seems to be the preferrable solution for warpage mitigation in mobile applications.This study explores several lidded solutions with different lid materials and thickness for warpage mitigation and compare the mechanical performance with other warpage mitigation techniques. The lidded packages considered for warpage mitigation are also evaluated for thermal performance during the transient workloads in a passive clamshell form factor. This study compares the thermal performance of lidded package and bare die flip chip modular package and addresses the role of interface resistance and lid material and thickness. With lidded design, the warpage can be controlled at room and elevated temperature, however, the thermal performance of the lidded package can be superior or inferior depending on the interface resistance and lid design compared to a bare die package.","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115675424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental analysis of heat transfer to shear-thinning viscoelastic coolants for optimizing surface topographies in immersed battery cooling systems","authors":"David Taylor, Leone Fasciati, Tamal Roy, D. Poulikakos","doi":"10.1109/iTherm54085.2022.9899669","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899669","url":null,"abstract":"In many novel applications, batteries undergo high charging and discharging rates, which, among other effects, leads to high thermal wear. Specifically the lifetime of Li-ion batteries reduces significantly under operation outside of a certain range of operating temperatures, which severely impairs the sustainability of the related applications. As air-cooling and pipe-based cooling systems often do not provide enough cooling power or temperature homogeneity, there currently exits strong interest in immersed battery cooling systems. To reach optimum heat transfer at minimum pumping power, the topography of the surface exposed to the coolant, as well as the coolant properties have to be optimized. Especially shear-thinning viscoelastic liquids seem to be promising candidates for coolants, as secondary flow patterns can arise in their flow at low Reynolds numbers. We here present an experimental setup, which allows evaluating different combinations of surface topography and coolant in a flow cavity with a geometry, which is directly relatable to flow between neighboring battery cells. We measure the maximum temperature, as well as the temperature gradient in flow direction of a heated structured sample plate exposed to flow of either pure water or water with 0.1% (w/w) xanthan added. We find that surface topography, which leads to a better cooling performance in combination with the former (Newtonian) coolant, loses this advantage when used with the latter (shear-thinning viscoelastic) coolant. We also find indications for secondary flow arising in the non-Newtonian liquid in combination with another surface geometry. This will help guiding the design of surface topographies for shear-thinning viscoelastic coolants.","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124287338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intra- and inter-device passive thermal management using solid-solid Nickel Titanium phase change materials","authors":"D. Sharar, Christopher Peters, K. Olver, Adam A. Wilson, H. Tsang, D. Altman","doi":"10.1109/iTherm54085.2022.9899587","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899587","url":null,"abstract":"This paper describes inter- and intra-device phase change material integration approaches using solid-solid Ni50.28Ti49.36 metallic alloys. First, we characterize Ni50.28Ti49.36 solid-solid phase change material using differential scanning calorimetry and Xenon Flash to reveal a material transformation temperature of 75°C, latent heat of 28 J/g, and thermal conductivity between 12 and 16 W/mK. Next, we perform electroless copper plating studies as a prerequisite for downstream printed circuit board integration. Finally, we design, fabricate, and test three unique board designs using x-ray imaging and electronic device heating via infrared thermography. The tested boards include a state of the art copper via board, a first-of-its-kind NiTi-impregnated printed circuit board, and a copper via board with backside NiTi integration. Results from this study demonstrate the ability to electroless plate NiTi, integrate into IPC-6012 E Class 3 printed circuit boards, and (in the test conditions used herein) provide up to a 65% increase in device on-time prior to reaching a critical device temperature. These results set the stage for leap-ahead improvement in the practical implementation of solid-solid thermal energy storage materials.","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124423923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correlation of Scanning Acoustic Microscopy and Transient Thermal Analysis to Identify Crack Growth in Solder Joints","authors":"M. Schmid, Joseph Hermann, E. Liu, G. Elger","doi":"10.1109/iTherm54085.2022.9899664","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899664","url":null,"abstract":"Solder joint reliability is one major issue in the solid-state lighting industry. Most lighting applications use white high-power LEDs with a ceramic submount soldered onto an Al-MCPCB (aluminum metal core PCB). This thermo-mechanical setup relieves the LED die from mechanical stress. However, now the solder joint becomes the bottleneck of the application due to the high CTE (coefficient of thermal expansion) mismatch between aluminum and ceramic. As a result, crack growth is initiated in the solder joint during aging, adverse for the heat dissipation from the LED. This increases the operation temperature of the LED leading to a reduced efficiency, a reduced lifetime, and a change in color. To obtain a better understanding of the thermal impact of solder joint cracks, this paper consolidates transient thermal analysis (TTA) and scanning acoustic microscopy (SAM) with a calibrated transient finite element (FE) model for a high-power LED. TTA data before thermal shock cycling is used to calibrate the FE model by an optimizer tool. Thereby a coefficient of determination of 0.9999 was achieved for the model. On the one hand, this optimized model was used to determine the thermal influence of crack size and location for dedicated sample LEDs after 1000 thermal shock cycles to further validate the accuracy. On the other hand, the optimized model was used to identify the most critical regions for crack growth. Hereby the relevance for heat dissipation of the thermal pad of the LED package was found to be significantly higher than one would expect from the geometrical dimensions.","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116131019","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}