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

{"title":"High Performance Compliant Heat Sinks","authors":"M. Schultz","doi":"10.1109/iTherm54085.2022.9899531","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899531","url":null,"abstract":"Removal of heat from semiconductor at power densities of 1 W/mm2 and higher has traditionally been the arena of liquid cooled cold plates in combination with a thermal interface material (TIM) coupling the cold plates to the heat generating devices. In standard rigid liquid cooled cold plate applications, the TIM is responsible to both conduct heat and absorb both static and dynamic mechanical surface mismatches between the cold plate and the device. This dual mission generally constrains the thermal performance of the TIM. In some applications like high power device test, the materials allowed for the TIM are further constrained, resulting in difficulty obtaining desired thermal performance. This work describes an innovative approach to conducting heat while providing mechanical compliance, allowing higher performance from most TIM’s and allowing a wider range of TIM’s for a given required thermal performance. The development of this approach from a heat conducting compliant interposer, to an interposer with an integrated high performance heat sink, to the final very high performance heat sink which flows liquid coolant through the compliant interposer structure incorporating high heat transfer fins is described. The heat sink provides junction to water thermal resistances as low as 16 Cmm2/W (including the full semiconductor die resistance) while greatly reducing variability in thermal resistance across the device being cooled when compared with rigid heat sinks. The high thermal performance is accomplished at reasonable pressure drop through the use of multiple manifolding of short 55 mm width channels and fins. Both mechanical and thermal response data are presented in detail.","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"43 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":"134286985","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":"Pool Boiling Heat Transfer Enhancement Using Femtosecond Laser Surface Processed Aluminum in Saturated PF-5060","authors":"Justin Costa-Greger, Logan Pettit, A. Reicks, S. Sarin, Chase Pettit, J. Shield, C. Zuhlke, G. Gogos","doi":"10.1109/iTherm54085.2022.9899590","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899590","url":null,"abstract":"In this work, pool boiling results using functionalized 6061 aluminum surfaces with PF-5060 as the working fluid are presented. Femtosecond laser surface processing (FLSP) is used as a surface modification technique to create self-organized, multiscale surface features which lead to additional nucleation sites and augmented surface area available for heat transfer. Two functionalized surfaces were fabricated by varying the laser fluence at a fixed pulse count to examine the impact of surface morphology on the heat transfer performance. In addition, each surface was tested under two conditions: as processed and post processed. Post processing consisted of a 60-minute ultrasonic bath to remove loosely adhered nanoparticles. Each surface was tested up to critical heat flux (CHF) and compared to a polished baseline sample. Results reveal drastically enhanced performance compared to the polished surface. The greatest increase in the maximum heat transfer coefficient was 459% for an FLSP surface without post processing. As processed only samples were shown to have a minor impact on the CHF, however, the inclusion of a post processing ultrasonic bath had significantly larger adverse effects on the CHF compared to their as processed counterparts. This adverse impact on the CHF arose from altering the nano-porous layer covering each surface feature, thereby reducing the surfaces’ ability to draw in cooler replenishing liquid to delay CHF. This work demonstrates the potential of FLSP-functionalized aluminum surfaces as a viable means of achieving significant two-phase heat transfer enhancement with dielectric fluids.","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"102 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":"132198024","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":"Reliability Characterization and Modeling of Flexible LCO battery Under Flexing and Calendar Aging for SOH degradation analysis","authors":"P. Lall, Hye-Yoen Jang, Scott Miller","doi":"10.1109/iTherm54085.2022.9899665","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899665","url":null,"abstract":"Flexible batteries have received a lot of attention owing to their thin form-factor and their wide applicability due to its flexibility and portability. Reliability of thin flexible power sources under stresses from human body motions are not well understood. Thin lithium-ion power source reliability may depend on use conditions, operating conditions, and storage prior to deployment. The use conditions are related to flexing stress cycles such as twist, fold, stretch, etc. as well as the charging and discharging cycles. Additionally, aging conditions are regarding to thermal aging and calendar aging. In this paper, the use cases have been replicated using lab setups to study the state-of-health degradation of thin power sources during charge-discharge cycling. The flexing test device has been used to replicate the stresses of daily motions, by administering 60-folding and twisting motions during 150 charge/discharging cycles. In addition, a simulation study by finite element method of multi-physics approach has been done for the better understanding of phenomenon of state of health degradation, electro-chemo-mechanical reactions, and life prediction. For the validation of the model, electro-chemical measurements via cyclic voltammetry method have been done. Consequently, various reliability characteristics, life expectations, electro-chemo-mechanical characteristics have been found.","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"43 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":"132337859","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 Fluid Assessment of Cylinders with Multiple Slots in Aligned Flow","authors":"Sultan Alshareef, T. Harman, T. Ameel","doi":"10.1109/iTherm54085.2022.9899624","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899624","url":null,"abstract":"The hydrodynamic and thermal performance of a circular cylinder with slots of different configurations in transverse flow is investigated. The first configuration consists of a cylinder with two slots, one aligned with the flow and the other in a perpendicular arrangement (two orthogonal slots). Each slot has a normalized slot width s/D = 0.2, where D is the cylinder diameter. The second configuration consists of a cylinder with two parallel slots aligned to the transverse free stream flow. The two slots are sized at s/D = 0.1 and are symmetrically placed on both sides of the cylinder centerline. The slots introduce additional heat transfer surface area between ~77% and ~109% for the orthogonal-slots and parallel-slots, respectively. Two-dimensional incompressible airflow for Reynolds numbers between 100 and 1000 is numerically simulated. The slotted cylinders are found to have a total drag force reduction up to ~30%, compared to a solid cylinder despite the additional viscous drag force of the slots. Convection heat transfer rate is enhanced up to ~81% and ~100% for the orthogonal-slot and the parallel-slot cylinders, respectively. Combining the hydrodynamic and thermal changes associated with the slotted cylinders, the performance index, defined as the ratio of the normalized heat rate to the normalized drag force, increases up to maximum of ~2.4 and ~2.8 for the orthogonal-slot and the parallel-slot cylinders, respectively, indicating better overall thermal-fluid performance. This enhancement is due in part to the additional heat transfer surface area and the reduced pressure drag from increased downstream external pressure caused by the interaction of the slot exhaust with the flow in the wake region. The easily fabricated, slotted cylindrical fins are capable of enhanced overall performance for cooling applications, such as electronic component heat dissipation.","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"146 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":"133423618","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":"Effect of SAC105 Solder Alloys High Strain Rate Property Evolution on Plastic Work at Low Operating Temperatures","authors":"P. Lall, Vikas Yadav, J. Suhling, David Locker","doi":"10.1109/iTherm54085.2022.9899520","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899520","url":null,"abstract":"Electronic devices in extreme harsh environment may endure the high thermal loads as well as high strain loads during their life span. Some of harsh environment applications include automotive and defense. Electronic devices may be exposed to high strain loads (1-100 per sec) such as drop & shock, vibration events. Thermal loads can be in range of -40°C to 125°C in these harsh conditions during their service, handling, or storage. Electronic industry migrated to leadfree solder alloy due to growing environmental concern in use of leaded solder alloys. The most used are SAC solder alloys including SAC105, SAC305. Leadfree solder behave differently due to drop-shock, and vibration loads. Therefore, knowing the mechanical performance of solder joint is essential to design and improve reliability of electronic products. Leadfree solder alloy constantly evolve due to thermal loads for prolonged duration which cause degradation in their mechanical properties. A better understanding of SAC solders is needed to improve design and for optimizing electronic package reliability, at low and high temperatures and strain rates. In addition, there is lack of constitutive model in published literature which capture the mechanical deformation under transient dynamic loads at low- and high-test temperature for aged conditions. In this paper, the evolution of Anand parameters for SAC105 lead free solder alloys at high strain rates has been investigated induced under sustained periods of thermal aging up to 1-year at 50°C. The thermal aged leadfree SAC105 solder specimen has been tested at high strain rates (10-75 per sec) at low operating temperatures of (-65 to 0°C) using tensile testing. Anand constitutive model has been used to describe nonlinear behavior of SAC105 solder. A good correlation was found between experimental data and Anand data. FE based model has been used to simulate the drop event for ball grid array package using Anand constitutive model to determine the plastic work and hysteresis loop over wide range of thermal aging and operating temperatures.","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":"130021872","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":"Effect of Prolonged Storage on High strain rate Mechanical properties of QSAC10 and QSAC20 Solders after Exposure to Isothermal Aging of 50°C","authors":"P. Lall, M. Saha, J. Suhling","doi":"10.1109/iTherm54085.2022.9899674","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899674","url":null,"abstract":"In Aerospace, military, automotive, space and oil exploration industries, various electronic parts may be subjected to sustained operation at high and low surrounding temperatures as well as high strain-rate loads. These parts may also be stored in non-climate-controlled enclosures prior to deployment. Previous research studies have shown that material properties of undoped SAC alloys evolve even at moderate temperatures after a prolonged period of storage. A variety of dopants has been introduced into SAC alloy formulations in order to reduce the aging effects. In this study, two doped SAC solder called QSAC10 and QSAC20 has been subjected to high strain rate testing after keeping them in storage at temperature of 50°C for duration of 30 days. Samples with no aging and 30 days aged samples have been subjected to uniaxial tensile tests to measure the mechanical properties of SAC+Bi solders. The High and Low operating temperature used in this experiment ranged from -65°C to 200°C. Then the experimental material data has been used to compute the constants for the Anand Visco-Plasticity model and then the model predictions of the uniaxial tensile test has been compared with the experimental data. The material constitutive behavior has been implemented in a finite element framework to simulate the drop events using the Anand constitutive model. The plastic work per shock event has also been determined which is a measure of the damage progression in the solder interconnects. Lastly, the constitutive model has been used to simulate the shock event of a ball-grid array package on printed circuit board assembly","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"25 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":"114874093","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":"Two-phase modeling for porous micro-channel evaporators","authors":"J. K. Mendizábal, R. L. Amalfi, R. Enright","doi":"10.1109/iTherm54085.2022.9899638","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899638","url":null,"abstract":"Two-phase (liquid/vapor) micro-channel cold plate evaporators are leading candidates for use in high-power electronics thermal management due to their superior convection heat transfer capabilities in comparison to single-phase (liquid) cold plates. In this context, novel micro-channel geometries and surface structuring are being pursued with the goal of obtaining thermofluidic performance enhancements and improved flow stability. Understanding the complex phenomena occurring within evaporators that govern the overall behavior, performance, and limitations of two-phase systems such as gravity-driven thermosyphon loops (TSL) is critical to the application of this thermal technology. Thus, developing comprehensive models that can provide insights into evaporator design, performance, and transient behavior is a key objective.We develop and validate a detailed numerical model for an evaporator design incorporating porous domains, where capillary pumping at the evaporator length scale augments the overall flow circulation within a gravity-driven TSL using either R245fa or R1233zd(E) as the working fluid. The modeling ambition includes capturing the physics at the interface between the porous and vapor domains, where a mix of direct evaporation, dry-out and liquid leakage can occur. The challenges addressed for such modeling include the implementation of the local variable phase interface conditions and a computationally efficient method of tracking the free liquid-vapor interface. We present results that suggest the design can realize significant improvements in thermofluidic performance, in terms of evaporator performance index defined as the inverse product of the pressure drop and thermal resistance, over a range of heat loads relevant to cooling high-power hardware components. The implications of the proposed evaporator design is the potential for extending the operating envelope of a TSL by reducing the overall pressure drops and modulating the passive refrigerant flow rate to achieve stable cooling and higher critical heat fluxes.","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"8 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":"115139404","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":"Effects of sedimentation induced filler thermal conductivity gradients on thermal reliability of potted components","authors":"Tejas Manohar Kesarkar, G. Balogh, Nitesh Kumar Sardana, Thomas Rupp","doi":"10.1109/iTherm54085.2022.9899597","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899597","url":null,"abstract":"In power electronic products, large components may be cooled by immersing each of the components in a cavity within the housing of the product. The small gap between the component and housing, which depends on mechanical tolerances and electrical isolation requirements, is then filled with a gap filler material (thermal potting). The gap filler forms an important conductive heat transfer path between the component and housing. This gap filler material is a colloidal suspension of small filler particles floating in a matrix, with the filler particles resulting in good bulk thermal conductivity. During assembly process, phenomenon of filler particle sedimentation occurs.Based on detailed thermal simulation models for certain components, it has been observed that the undesired thermal conductivity gradients due to sedimentation result in temperature rise of the order of 10 K. Certain limitations of assembly technologies limit the potting height achievable, further increasing the thermal aggravation due to variation in thermal conductivity.In this paper, using thermal simulation models, we study the effects of sedimentation induced filler thermal conductivity gradients on temperatures of cooled components, for a range of potting heights and gap sizes.","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"10 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":"133868590","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":"From 2.5D to 3D Chiplet Systems: Investigation of Thermal Implications with HotSpot 7.0","authors":"Jun-Han Han, Xinfei Guo, K. Skadron, M. Stan","doi":"10.1109/iTherm54085.2022.9899649","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899649","url":null,"abstract":"Recent advanced packaging technologies such as 2.5D chiplet-package offer a modular approach to increasing yield over monolithic SoC designs. As 2.5D chiplet systems shed light on reducing product development times and costs, 3D chiplet systems can extend the benefits furthermore by offering more remarkable performance. As semiconductor technology continues, the significance of thermal management has arisen even for a monolithic chip. When it comes to 3D chiplet systems, thermal issue remains being one of the most critical obstacles to transitioning from 2.5D to 3D. Microfluidic cooling has been proved to be a promising cooling solution, yet the actual detailed thermal indications for making the direct transition under this cooling strategy are still missing. HotSpot 7.0 emerged as the latest pre-RTL thermal analysis framework that introduced a novel thermal management method using microfluidic cooling on the widely used pre-RTL power and thermal simulator. This paper presents evolution investigations from 2.5D to microfluidic-cooled 3D integration from the thermal management aspect using HotSpot 7.0. We studied a typical 2.5D chiplet as an example, and it has one processor chip in the center and four high bandwidth memory (HBM) chips on the sides. The thermal management method with microfluidics reduces the maximum temperature of 2.5D and 3D chiplet by 47.2°C and 63.83°C, respectively. In addition, as a high-performance system example, a hypothetical processor-processor integration is investigated. The simulation results show that the conventional air convection type is hard to maintain the chiplet temperature under the operating temperature range. Microfluidic cooling is advantageous in heat dissipation and heat spreading. The cooling capacity is dependent on the pump pressure. Multi-layer cooling is a promising cost-effective solution for the 3D chiplet system.","PeriodicalId":351706,"journal":{"name":"2022 21st IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (iTherm)","volume":"300 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":"133374347","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":"Size Determination of Voids in the Soldering of Automotive DC/DC-Converters via IR Thermography","authors":"Nils-Malte Jahn, M. Pfost","doi":"10.1109/iTherm54085.2022.9899529","DOIUrl":"https://doi.org/10.1109/iTherm54085.2022.9899529","url":null,"abstract":"In this work, a method for the size determination of voids in the solder layer between the leadframe of a discrete semiconductor in an SO-8FL package and the underlying circuit board is proposed. The devices under test are heated by a short high-power pulse and the thermal response of the surrounding copper layers close to drain and source is observed by an infrared camera. The heat flow from the junction to the drain and source copper layers is affected by voids in the solder layer. Specially, the heat flow towards the drain copper layer is impeded and a surge in the heat flow towards the source copper layer is expected. Experimental data show that the ratio of the source and drain temperature rise is related to the void share in the solder layer, which is determined prior to the investigation via x-ray examination. Disturbance factors are evaluated and a suitable approach for the usage of the findings of this work in end-of-line-testing is suggested.","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":"129329844","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}