Pub Date : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190543
Tyler J. Shelly, J. Weibel, D. Ziviani, E. Groll
As vehicle electrification is expanding in response to more stringent emissions standards and shifting consumer preferences, extending the driving range remains critical to broadening the adoption of battery electric vehicles (BEV). This challenge can be addressed in part through more efficient operation of the thermal management system in BEVs, which has a significant influence on range and performance, especially under extreme weather conditions. This study develops a simulation framework for the analysis of a BEV thermal management systems under long-range test procedures defined by the Multi-Cycle Test (MCT). A baseline thermal management system configuration is defined to reflect those typically found in long-range BEVs, so as to provide insight into the design and performance of current systems. Parametric studies are conducted across a range of ambient conditions from 0 °C to 40 °C and drive cycles including urban/city (UDDS), highway (HFEDS), and constant speed cycles. Operating temperature setpoints for the cabin, battery, electronics, and other components are met using the standard system configuration, albeit with significant deleterious impacts on vehicle range and cycle control. At low ambient temperatures, a maximum 30% decrease in driving range is predicted. Across the parametric values investigated, the choice of cabin setpoint temperature affects the driving range on the order of ~10% across heating and cooling cases. The transient drive cycle response for representative cooling cases is presented and reveals oscillations in system behavior about the chosen setpoints; these oscillations are a direct result of the secondary loop liquid cooling architecture. As a result of the present study, perspectives on alternative system configurations that offer battery thermal management and cabin comfort as well as the integration of waste heat recovery are outlined as future work.
{"title":"A Dynamic Simulation Framework for the Analysis of Battery Electric Vehicle Thermal Management Systems","authors":"Tyler J. Shelly, J. Weibel, D. Ziviani, E. Groll","doi":"10.1109/ITherm45881.2020.9190543","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190543","url":null,"abstract":"As vehicle electrification is expanding in response to more stringent emissions standards and shifting consumer preferences, extending the driving range remains critical to broadening the adoption of battery electric vehicles (BEV). This challenge can be addressed in part through more efficient operation of the thermal management system in BEVs, which has a significant influence on range and performance, especially under extreme weather conditions. This study develops a simulation framework for the analysis of a BEV thermal management systems under long-range test procedures defined by the Multi-Cycle Test (MCT). A baseline thermal management system configuration is defined to reflect those typically found in long-range BEVs, so as to provide insight into the design and performance of current systems. Parametric studies are conducted across a range of ambient conditions from 0 °C to 40 °C and drive cycles including urban/city (UDDS), highway (HFEDS), and constant speed cycles. Operating temperature setpoints for the cabin, battery, electronics, and other components are met using the standard system configuration, albeit with significant deleterious impacts on vehicle range and cycle control. At low ambient temperatures, a maximum 30% decrease in driving range is predicted. Across the parametric values investigated, the choice of cabin setpoint temperature affects the driving range on the order of ~10% across heating and cooling cases. The transient drive cycle response for representative cooling cases is presented and reveals oscillations in system behavior about the chosen setpoints; these oscillations are a direct result of the secondary loop liquid cooling architecture. As a result of the present study, perspectives on alternative system configurations that offer battery thermal management and cabin comfort as well as the integration of waste heat recovery are outlined as future work.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129799853","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 : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190255
J. Nonneman, S. Schlimpert, I. T’Jollyn, M. Paepe
This paper presents the modelling and validation of an advanced thermal lumped parameter (LP) model for a stator tooth of a switched reluctance motor (SRM) with a dry lateral slot cooling method. Standard and simple lumped parameter models for electric motors can insufficiently predict the temperature distribution within the components of the motor. In standard LP models, only several nodes are used to model each component, while more accurate models are needed to predict the effect of different cooling methods on the thermal performance of the motor without the need for experiments. A fully 3D thermal finite element (FE) model could be used but this would increase effort, complexity and computing time unnecessarily. Therefore, an advanced 3D LP model including the dry lateral slot cooling method was developed and validated based on experiments on a real stator tooth cooled with the modelled cooling method. The 3D LP model is extracted from a 2D FE radial simulation of the stator tooth and extended axially in 3D to include axial heat transfer. Experiments were performed with a setup consisting of one tooth of a SRM without rotor, but including stator iron, one winding and two triangular stainless steel tubes in the slots at both sides of the winding cooled by a 60/40% mixture by mass of water-glycol. The setup is equipped with several thermocouples integrated within the components to determine the component temperatures. Three inlet temperatures (20, 35 and 50°C) and four flow rates (2, 6, 9 and 13 l/min) of the coolant were tested at three different heat losses in the winding (10, 30 and 50 W). A comparison between the simulated and measured temperatures showed generally higher temperatures in the experiment. The presence of imperfections in the manufacturing of the experimental setup was determined as the cause of this offset. These imperfections result in lower material thermal conductivities and higher contact resistances than expected from scientific literature. After fitting those thermal properties on the measurements, similar simulated temperatures could be obtained as in the experiments.
{"title":"Modelling and Validation of a Switched Reluctance Motor Stator Tooth with Direct Coil Cooling","authors":"J. Nonneman, S. Schlimpert, I. T’Jollyn, M. Paepe","doi":"10.1109/ITherm45881.2020.9190255","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190255","url":null,"abstract":"This paper presents the modelling and validation of an advanced thermal lumped parameter (LP) model for a stator tooth of a switched reluctance motor (SRM) with a dry lateral slot cooling method. Standard and simple lumped parameter models for electric motors can insufficiently predict the temperature distribution within the components of the motor. In standard LP models, only several nodes are used to model each component, while more accurate models are needed to predict the effect of different cooling methods on the thermal performance of the motor without the need for experiments. A fully 3D thermal finite element (FE) model could be used but this would increase effort, complexity and computing time unnecessarily. Therefore, an advanced 3D LP model including the dry lateral slot cooling method was developed and validated based on experiments on a real stator tooth cooled with the modelled cooling method. The 3D LP model is extracted from a 2D FE radial simulation of the stator tooth and extended axially in 3D to include axial heat transfer. Experiments were performed with a setup consisting of one tooth of a SRM without rotor, but including stator iron, one winding and two triangular stainless steel tubes in the slots at both sides of the winding cooled by a 60/40% mixture by mass of water-glycol. The setup is equipped with several thermocouples integrated within the components to determine the component temperatures. Three inlet temperatures (20, 35 and 50°C) and four flow rates (2, 6, 9 and 13 l/min) of the coolant were tested at three different heat losses in the winding (10, 30 and 50 W). A comparison between the simulated and measured temperatures showed generally higher temperatures in the experiment. The presence of imperfections in the manufacturing of the experimental setup was determined as the cause of this offset. These imperfections result in lower material thermal conductivities and higher contact resistances than expected from scientific literature. After fitting those thermal properties on the measurements, similar simulated temperatures could be obtained as in the experiments.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130583102","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 : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190170
Mei-Ling Wu, Wei-Jhih Wong
As the electronic products, such as smart phones, notebooks, and micro-control parts for vehicles, are becoming increasingly popular and their size continues do decrease, there is also a need to reduce the volume of ultra-thin silicon wafers while improving their performance. At present, backside grinding is typically used for this purpose, and requires that the wafer is placed on the chuck of a self-rotating wheel, while controlling the feed rate in order to reduce wafer thickness. Although this process is efficient and effective, it may result in subsurface damage, surface cracks, micro-cracks, warpage, and other undesirable effects. One of its main drawbacks is residual stress, which becomes more pronounced in very thin wafers, as this increases rigidity. Stoney equation is widely used to examine the residual stress and curvature radius in a silicon wafer due to the backside grinding process. However, the relationship between the residual stress generated in the wafer during the grinding process and the process parameters is rarely analyzed through simulations. This gap is addressed in the present study, whereby the finite element method (FEM) is adopted to examine the effects of different process parameters, as well as wafer thickness, on the residual stress. As dynamic simulation is adopted, this allows the process parameters to be adjusted at runtime to predict the residual stress, while Stoney’s equation is employed to predict the influence of different process parameters on warpage. Based on the obtained results, the wafer warpage caused by the process can be predicted with acceptable accuracy, which can in turn be used to optimize the process parameter values to minimize wafer warpage.
{"title":"Simulation Method of Ultra-Thin Silicon Wafers Warpage","authors":"Mei-Ling Wu, Wei-Jhih Wong","doi":"10.1109/ITherm45881.2020.9190170","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190170","url":null,"abstract":"As the electronic products, such as smart phones, notebooks, and micro-control parts for vehicles, are becoming increasingly popular and their size continues do decrease, there is also a need to reduce the volume of ultra-thin silicon wafers while improving their performance. At present, backside grinding is typically used for this purpose, and requires that the wafer is placed on the chuck of a self-rotating wheel, while controlling the feed rate in order to reduce wafer thickness. Although this process is efficient and effective, it may result in subsurface damage, surface cracks, micro-cracks, warpage, and other undesirable effects. One of its main drawbacks is residual stress, which becomes more pronounced in very thin wafers, as this increases rigidity. Stoney equation is widely used to examine the residual stress and curvature radius in a silicon wafer due to the backside grinding process. However, the relationship between the residual stress generated in the wafer during the grinding process and the process parameters is rarely analyzed through simulations. This gap is addressed in the present study, whereby the finite element method (FEM) is adopted to examine the effects of different process parameters, as well as wafer thickness, on the residual stress. As dynamic simulation is adopted, this allows the process parameters to be adjusted at runtime to predict the residual stress, while Stoney’s equation is employed to predict the influence of different process parameters on warpage. Based on the obtained results, the wafer warpage caused by the process can be predicted with acceptable accuracy, which can in turn be used to optimize the process parameter values to minimize wafer warpage.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122416537","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}
In this paper, we analyze the heat generation characteristics of components in a multi-stack PCB (Printed Circuit Board) structure of smart phone and find the optimized structure of components placement to minimize system temperature. The PCB in a smart device is conventionally composed of a single layer, so that components are placed on one side or both sides of single PCB. However, as the performance of components goes up, power consumption and the battery size have been gradually increased in order to maximize the running time. Accordingly, in order to increase the battery size in limited space of the smart phone, it is necessary to reduce PCB area on which the components are mounted. Recently, mobile phone makers are gradually adopting a new structure in which PCBs are stacked in multiple layers to increase mounting area. As a result, the heat generation phenomenon needs to be examined from a different viewpoint than the existing single layer PCB structure. In case of existing single-layer PCB, components can be contacted to heat spreader (heat pipe, bracket, metal or graphite sheet) through TIM. On the other hand, in case of multi-layer PCB configuration, components in between two boards have no direct contact with heat spreader and it makes chip temperature higher than before. We analyze chip temperature for different board placement of multi-stacked PCB in smart phone considering thermal performance. The location of high power components such as AP (Application Processor), RF, PMIC, CP (Communication Processor), and Flash Memory was a parameter. Finally, we can find optimal configuration that minimizes the max junction temperature for multiple power scenario.
{"title":"Thermal Aware 3-D Floorplanning on Multi-stacked Board of Smart Phone","authors":"Youngsang Cho, Heejung Choi, Heeseok Lee, Yunkyeok Im, Hoi-Jin Lee, Youngmin Shin","doi":"10.1109/ITherm45881.2020.9190384","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190384","url":null,"abstract":"In this paper, we analyze the heat generation characteristics of components in a multi-stack PCB (Printed Circuit Board) structure of smart phone and find the optimized structure of components placement to minimize system temperature. The PCB in a smart device is conventionally composed of a single layer, so that components are placed on one side or both sides of single PCB. However, as the performance of components goes up, power consumption and the battery size have been gradually increased in order to maximize the running time. Accordingly, in order to increase the battery size in limited space of the smart phone, it is necessary to reduce PCB area on which the components are mounted. Recently, mobile phone makers are gradually adopting a new structure in which PCBs are stacked in multiple layers to increase mounting area. As a result, the heat generation phenomenon needs to be examined from a different viewpoint than the existing single layer PCB structure. In case of existing single-layer PCB, components can be contacted to heat spreader (heat pipe, bracket, metal or graphite sheet) through TIM. On the other hand, in case of multi-layer PCB configuration, components in between two boards have no direct contact with heat spreader and it makes chip temperature higher than before. We analyze chip temperature for different board placement of multi-stacked PCB in smart phone considering thermal performance. The location of high power components such as AP (Application Processor), RF, PMIC, CP (Communication Processor), and Flash Memory was a parameter. Finally, we can find optimal configuration that minimizes the max junction temperature for multiple power scenario.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122833148","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 : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190289
W. Ahn, Yongyun B. Kim, Inkeun Ryu, Daeil Kim
This study is about the thermal management of camera component in vehicle cockpit. A thermal management is necessary because it is directly related to abnormal operation and user's safety, if the camera components have a high temperature. The highest temperature component among the camera module is camera multi-processor chip, the forced convection is used to reduce the temperature of the component in the vehicle stage. The most commonly used method of the forced convection in the vehicle stage is a fan control using ducts. In the vehicle stage, the duct location is normally fixed and limited for changing. In the limited systems, a method of adding or removing the number of the vent and a controlling the direction of the air using the duct are proposed. In addition, the flow-guide is designed and also proposed to control the direction of flow. The number of vents controls the flow to the outlet, while the guide directly controls the flow direction to provide a cooling solution for the heat generation. As the same methodology, this study can provide a fan flow solution to control high temperature of camera components.
{"title":"Active Thermal Management of Automotive Camera Components","authors":"W. Ahn, Yongyun B. Kim, Inkeun Ryu, Daeil Kim","doi":"10.1109/ITherm45881.2020.9190289","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190289","url":null,"abstract":"This study is about the thermal management of camera component in vehicle cockpit. A thermal management is necessary because it is directly related to abnormal operation and user's safety, if the camera components have a high temperature. The highest temperature component among the camera module is camera multi-processor chip, the forced convection is used to reduce the temperature of the component in the vehicle stage. The most commonly used method of the forced convection in the vehicle stage is a fan control using ducts. In the vehicle stage, the duct location is normally fixed and limited for changing. In the limited systems, a method of adding or removing the number of the vent and a controlling the direction of the air using the duct are proposed. In addition, the flow-guide is designed and also proposed to control the direction of flow. The number of vents controls the flow to the outlet, while the guide directly controls the flow direction to provide a cooling solution for the heat generation. As the same methodology, this study can provide a fan flow solution to control high temperature of camera components.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"196 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120961110","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 : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190179
Alisha Piazza, Sougata Hazra, K. Jung, M. Degner, M. Gupta, E. Jih, M. Asheghi, K. Goodson
Embedded microchannel with 3D manifold heat sinks (EMMCs) offer two primary advantages over conventional microchannel heat sinks: increased thermal performance and decreased pressure loss. The unique 3D fluid routing mechanism of the manifold reduces pressure losses and, resultantly, reduces required pumping power. Previous simulations and experimental studies have been limited to cooling of small footprint electronics, typically on the order of 5×5mm2. This work explores the effects of scaling up the footprint of the cooling area using single phase water. A constant heat flux is applied at the top of the microchannel cold plate and the manifold routes fluid in and out of this cold plate. Achieving similar thermal performance with a larger footprint necessitates scaling flow rate approximately proportional to area. Therefore, significantly higher pressure losses are expected as the heater area is scaled up from 5×5mm2 to 20×20mm2. For example, in order to achieve a target performance of 0.078 cm2-K/W, pressure drops from the inlet to outlet are 2 and 35 kPa for the 5×5mm2 and 20×20mm2, respectively. In addition, increasing the flow rate of liquid results in the location of the hottest spot on the device shifting away from the center of the device. Finally, this paper discusses ongoing and future experimental work and methods of improving thermal and pressure performance in large-scale EMMCs.
{"title":"Considerations and Challenges for Large Area Embedded Micro-channels with 3D Manifold in High Heat Flux Power Electronics Applications","authors":"Alisha Piazza, Sougata Hazra, K. Jung, M. Degner, M. Gupta, E. Jih, M. Asheghi, K. Goodson","doi":"10.1109/ITherm45881.2020.9190179","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190179","url":null,"abstract":"Embedded microchannel with 3D manifold heat sinks (EMMCs) offer two primary advantages over conventional microchannel heat sinks: increased thermal performance and decreased pressure loss. The unique 3D fluid routing mechanism of the manifold reduces pressure losses and, resultantly, reduces required pumping power. Previous simulations and experimental studies have been limited to cooling of small footprint electronics, typically on the order of 5×5mm2. This work explores the effects of scaling up the footprint of the cooling area using single phase water. A constant heat flux is applied at the top of the microchannel cold plate and the manifold routes fluid in and out of this cold plate. Achieving similar thermal performance with a larger footprint necessitates scaling flow rate approximately proportional to area. Therefore, significantly higher pressure losses are expected as the heater area is scaled up from 5×5mm2 to 20×20mm2. For example, in order to achieve a target performance of 0.078 cm2-K/W, pressure drops from the inlet to outlet are 2 and 35 kPa for the 5×5mm2 and 20×20mm2, respectively. In addition, increasing the flow rate of liquid results in the location of the hottest spot on the device shifting away from the center of the device. Finally, this paper discusses ongoing and future experimental work and methods of improving thermal and pressure performance in large-scale EMMCs.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127874812","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 : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190491
Sevket U. Yuruker, R. Mandel, P. McCluskey, M. Ohadi
Thermal management of electronics has been a major limiting factor in achieving high-power, high-performance systems. Isolating various heat dissipating components from each other becomes significantly difficult as increasingly higher packaging densities are targeted. Thus, components with different heat dissipation rates and allowable temperatures are thermally coupled due to increased proximity. The packaging configuration, positioning of the active components and the chosen heat removal techniques play an important role in determining the overall power consumption, efficiency, reliability and expected lifetime. Consequently, evaluation of the electro-thermal characteristics on the system-level becomes as critical as the component-level in order to adequately capture the effects that components have on each other. Also, through a system-level evaluation, limiting quantities such as the maximum ambient temperature, the cooling sequence of the components and the flow routing can be ascertained for a given assembly. Optimization of the design, selection of the appropriate working fluid and prevention of catastrophic failures such as thermal runaway, can be possible through utilization of a system-level thermal model. This study presents a MATLAB based system-level thermal model with an iterative solver that incorporates temperature dependent characteristics. The model is used to design and optimize the thermal management approach of a high-power full bridge DC-DC converter module. Comparison of various flow routing configurations and heat removal modes’ effect on overall performance, along with other advantageous conclusions drawn through several design iterations are performed using the system-level model and are illustrated in detail.
{"title":"System-Level Thermal Modeling and Its Significance in Electronics Packaging","authors":"Sevket U. Yuruker, R. Mandel, P. McCluskey, M. Ohadi","doi":"10.1109/ITherm45881.2020.9190491","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190491","url":null,"abstract":"Thermal management of electronics has been a major limiting factor in achieving high-power, high-performance systems. Isolating various heat dissipating components from each other becomes significantly difficult as increasingly higher packaging densities are targeted. Thus, components with different heat dissipation rates and allowable temperatures are thermally coupled due to increased proximity. The packaging configuration, positioning of the active components and the chosen heat removal techniques play an important role in determining the overall power consumption, efficiency, reliability and expected lifetime. Consequently, evaluation of the electro-thermal characteristics on the system-level becomes as critical as the component-level in order to adequately capture the effects that components have on each other. Also, through a system-level evaluation, limiting quantities such as the maximum ambient temperature, the cooling sequence of the components and the flow routing can be ascertained for a given assembly. Optimization of the design, selection of the appropriate working fluid and prevention of catastrophic failures such as thermal runaway, can be possible through utilization of a system-level thermal model. This study presents a MATLAB based system-level thermal model with an iterative solver that incorporates temperature dependent characteristics. The model is used to design and optimize the thermal management approach of a high-power full bridge DC-DC converter module. Comparison of various flow routing configurations and heat removal modes’ effect on overall performance, along with other advantageous conclusions drawn through several design iterations are performed using the system-level model and are illustrated in detail.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130388117","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 : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190593
Andrew Latulippe, Y. Ait-El-Aoud, R. Osgood, Hongwei Sun
Introduced is a low cost "cantilever" like device that is capable of generating heat and simultaneously measuring temperature. The device is fabricated on flexible polyimide substrate using a photolithography process to form thin gold heater patterns. Heat generation is concentrated at the tip of the cantilever using Joule heating from a direct current. The heater functions as an RTD capable of accurate temperature measurements. The device is used to measure the thermal conductivity of small, high aspect ratio structures such as fibers by measuring the thermal resistance using a parallel resistance model. Using a thin platinum wire as a reference material, accurate values for thermal conductivity are obtained.
{"title":"Fabrication of a Low Cost Flexible Micro-Device for Measuring Fiber Thermal Conductivity","authors":"Andrew Latulippe, Y. Ait-El-Aoud, R. Osgood, Hongwei Sun","doi":"10.1109/ITherm45881.2020.9190593","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190593","url":null,"abstract":"Introduced is a low cost \"cantilever\" like device that is capable of generating heat and simultaneously measuring temperature. The device is fabricated on flexible polyimide substrate using a photolithography process to form thin gold heater patterns. Heat generation is concentrated at the tip of the cantilever using Joule heating from a direct current. The heater functions as an RTD capable of accurate temperature measurements. The device is used to measure the thermal conductivity of small, high aspect ratio structures such as fibers by measuring the thermal resistance using a parallel resistance model. Using a thin platinum wire as a reference material, accurate values for thermal conductivity are obtained.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131040415","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 : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190529
Weihao Li, Longguang Zhu, Feng Ji, Jinling Yu, Yufeng Jin, Wei Wang
In the study of chip heat dissipation, micro-channel heat sinks have been widely used. Microchannel heat sink have a variety of structures, among which the manifold structure is used more because of its better heat dissipation performance. However, the manifold structure has the problem of uneven flow distribution. In order to solve this problem, this paper uses the principle of similar flow resistance and resistance to establish the equivalent resistance model of the manifold microchannel. This model simulates the equivalent resistance network by MATLAB, simulates the change of the flow channel by changing Rr, simulates the change of the distribution channel by changing Rd, and simulates the outlet position by changing the position of the negative electrode of the power supply. The results of the circuit simulation are used as a direction guide, and thermal simulation is performed using COMSOLTM. The optimization of the reaction channel, the distribution channel and the outlet position of the manifold structure is completed. Finally, a uniform flow distribution was achieved, and the variance of the surface temperature of the heat source was reduced by 66%. It can be seen from experiments that the equivalent resistance model has an important role in guiding the optimization direction in the research of microchannel heat sink with manifold structure.
{"title":"Optimization of Manifold Mmicrochannel Heat Sink Based on Equivalent Resistance Model","authors":"Weihao Li, Longguang Zhu, Feng Ji, Jinling Yu, Yufeng Jin, Wei Wang","doi":"10.1109/ITherm45881.2020.9190529","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190529","url":null,"abstract":"In the study of chip heat dissipation, micro-channel heat sinks have been widely used. Microchannel heat sink have a variety of structures, among which the manifold structure is used more because of its better heat dissipation performance. However, the manifold structure has the problem of uneven flow distribution. In order to solve this problem, this paper uses the principle of similar flow resistance and resistance to establish the equivalent resistance model of the manifold microchannel. This model simulates the equivalent resistance network by MATLAB, simulates the change of the flow channel by changing Rr, simulates the change of the distribution channel by changing Rd, and simulates the outlet position by changing the position of the negative electrode of the power supply. The results of the circuit simulation are used as a direction guide, and thermal simulation is performed using COMSOLTM. The optimization of the reaction channel, the distribution channel and the outlet position of the manifold structure is completed. Finally, a uniform flow distribution was achieved, and the variance of the surface temperature of the heat source was reduced by 66%. It can be seen from experiments that the equivalent resistance model has an important role in guiding the optimization direction in the research of microchannel heat sink with manifold structure.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131065504","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 : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190530
P. Lall, Tony Thomas, K. Blecker
Remaining Useful Life (RUL) estimation of electronic packages for different conditions of vibration loads and temperatures have various applications in scheduling maintenance and component replacement effectively to reduce the cost of the same. In this study, SAC305 alloy is used as the solder alloy, and the RUL is estimated using different particle filtering and time-series analysis techniques. The test board is a lead-free SAC305 daisy chain CABGA package which is subjected to different temperatures 25oC, 55oC, 100oC and 155oC for two vibration acceleration levels of 5g and 10g. The vibration of the test board is carried out to its first natural frequency for all conditions of temperature and vibration load. Strain signals are acquired using data acquisition and signal amplifying unit from four separate locations of the test board at a frequent time interval during vibration as the parameter used for predicting failure. In-situ measurements of resistance of the packages are also measured to identify the failure of the packages during vibration. The strain signals acquired at regular intervals during vibration at different locations of the board are used to find the feature vectors that can predict failure. Principal component analysis (PCA) is used as the data reduction technique for both time and frequency-based features of the strain signal. Feature vectors are estimated from the time, frequency, and spectral content of the strain signal using different multivariate statistical techniques. The variations in the feature vectors for different conditions of temperature and load is studied by combining all the feature vector data together and analyzing it for different patterns. The correlation of the same is studied to understand the changes in the feature vectors with different conditions. The two major feature vectors that can predict the failure includes frequency and spectral content from 500 Hz to 2000 Hz of the strain signal and the instantaneous frequency of the whole strain signal.
{"title":"RUL Estimations of SAC305 Solder PCB's under Different Conditions of Temperature and Vibration Loads","authors":"P. Lall, Tony Thomas, K. Blecker","doi":"10.1109/ITherm45881.2020.9190530","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190530","url":null,"abstract":"Remaining Useful Life (RUL) estimation of electronic packages for different conditions of vibration loads and temperatures have various applications in scheduling maintenance and component replacement effectively to reduce the cost of the same. In this study, SAC305 alloy is used as the solder alloy, and the RUL is estimated using different particle filtering and time-series analysis techniques. The test board is a lead-free SAC305 daisy chain CABGA package which is subjected to different temperatures 25oC, 55oC, 100oC and 155oC for two vibration acceleration levels of 5g and 10g. The vibration of the test board is carried out to its first natural frequency for all conditions of temperature and vibration load. Strain signals are acquired using data acquisition and signal amplifying unit from four separate locations of the test board at a frequent time interval during vibration as the parameter used for predicting failure. In-situ measurements of resistance of the packages are also measured to identify the failure of the packages during vibration. The strain signals acquired at regular intervals during vibration at different locations of the board are used to find the feature vectors that can predict failure. Principal component analysis (PCA) is used as the data reduction technique for both time and frequency-based features of the strain signal. Feature vectors are estimated from the time, frequency, and spectral content of the strain signal using different multivariate statistical techniques. The variations in the feature vectors for different conditions of temperature and load is studied by combining all the feature vector data together and analyzing it for different patterns. The correlation of the same is studied to understand the changes in the feature vectors with different conditions. The two major feature vectors that can predict the failure includes frequency and spectral content from 500 Hz to 2000 Hz of the strain signal and the instantaneous frequency of the whole strain signal.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131658978","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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