J. Dai, Yuexin Zhang, ZK Li, Mingming Chen, Yuhua Guo, Zhekun Fan, Junhui Li
{"title":"Research on Reliability of Ni/Sn/Cu(Ni) Copper Pillar Bump Under Thermoelectric Loading","authors":"J. Dai, Yuexin Zhang, ZK Li, Mingming Chen, Yuhua Guo, Zhekun Fan, Junhui Li","doi":"10.1115/1.4053889","DOIUrl":"https://doi.org/10.1115/1.4053889","url":null,"abstract":"\u0000 With the development of packaging devices towards high performance and high density, electronic devices are subjected to thermos-electric stresses under service conditions, which has become a particularly important reliability problem in microelectronics packaging. The reliability of the chip under thermo-electric stresses is studied in this paper. Firstly, thermo-electric coupling experiments were carried out on two solder joint structures of Ni/Sn3.5Ag/Cu and Ni/Sn3.5Ag/Ni. The interface evolution of solder joints under different current densities was analyzed. The reliability of the two structures under thermo-electric stresses was compared and analyzed. After that, three-dimensional finite element analysis was employed to simulate the current density, Joule heat, and temperature distribution of the flip chip. Finally, through the combination of experiment and simulation, the distribution of Joule heat and temperature of the chip was analyzed. The results show that the Ni/Sn3.5Ag/Ni structure has better reliability than the Ni/Sn3.5Ag/Cu structure under thermal-electric coupling. In addition, when the Ni layer was used as the cathode side, and the current density was higher than 5×104A/cm2, the dissolution failure of the Ni layer occurred in two structures. Because the higher current density generated a large amount of Joule heat where the current was crowded, resulting in excessively high temperature and rapid dissolution of the Ni barrier layer.","PeriodicalId":15663,"journal":{"name":"Journal of Electronic Packaging","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44655729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A New Structure of Ceramic Substrate to Reduce the Critical Electric Field in High Voltage Power Modules","authors":"Feifei Yan, Laili Wang, Yongmei Gan, Kaixuan Li, Boya Zhang","doi":"10.1115/1.4053891","DOIUrl":"https://doi.org/10.1115/1.4053891","url":null,"abstract":"\u0000 The blocking voltage level of silicon carbide (SiC) can reach 10 to 25 kV, which will significantly increase the power density and capacity of power modules. However, high voltage can induce high electric field, increase the risk of partial discharge (PD) and threaten the insulation reliability. This paper focuses on the triple points between the metal electrode, silicone gel, and ceramic in power modules. The influencing factors of electric field at different triple points are fully analyzed. PD experiments are performed and the results show that interface between silicone gel and ceramic is a weak area of insulation. Therefore, this paper demonstrates that area of weak insulation and high electric field meet at the triple point. To solve this problem, a new structure of ceramic substrate is proposed, which isolates the interface area from high electric field. At the same time, the new structure can significantly reduce the high electric field reinforcement.","PeriodicalId":15663,"journal":{"name":"Journal of Electronic Packaging","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44700936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohammad I. Tradat, Yaman M. Manaserh, Ahmad R. Gharaibeh, B. Sammakia, D. Hall, K. Nemati, M. Seymour
{"title":"Experimental and Numerical Analysis of Data Center Pressure and Flow Fields Induced by Backward and Forward Crah Technology","authors":"Mohammad I. Tradat, Yaman M. Manaserh, Ahmad R. Gharaibeh, B. Sammakia, D. Hall, K. Nemati, M. Seymour","doi":"10.1115/1.4053890","DOIUrl":"https://doi.org/10.1115/1.4053890","url":null,"abstract":"\u0000 An increasingly common power saving practice in data center thermal management is to swap out air cooling unit blower fans with electronically commutated plug fans, the side effects of which are not fully understood. Therefore, it has become necessary to develop an overall understanding of backward curved blowers and compare the resulting flow, pressure, and temperature fields with forward curved ones in which the induced fields are characterized, compared and visualized in a reference data center. In this study, experimental and numerical characterization of backward curved blowers is introduced. Then, a physics-based Computational Fluid Dynamics model is built using the 6SigmaRoomTM tool to predict/simulate the measured fields. The parametric and sensitivity of the baseline modeling are investigated and considered. Different operating conditions are applied at the room level for experimental characterization, comparison, and illustration of the interaction between different CRAH technologies. The measured data is plotted and compared with the CFD model assessment to visualize the fields of interest. The results show that the fields are highly dependent on CRAH technology. The tile to CRAH airflow ratios for the flow constraints of scenarios 1, 2, 3, and 4 are 85.5%, 83.9%, 61%, and 59%, respectively. The corresponding leakage ratios are 14.5%, 16%, 38.9%, and 41%, respectively. Furthermore, the validated CFD model was used to investigate and compare the airflow pattern and plenum pressure distribution. Lastly, it is notable that a potential side effect of backward curved technology is the creation of airflow dead zone.","PeriodicalId":15663,"journal":{"name":"Journal of Electronic Packaging","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43698584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lou Schuler, L. Chamoin, Z. Khatir, M. Berkani, M. Ouhab, N. Degrenne
{"title":"A Reduced Model Based On Proper Generalized Decomposition for the Fast Analysis of Igbt Power Modules Lifetime","authors":"Lou Schuler, L. Chamoin, Z. Khatir, M. Berkani, M. Ouhab, N. Degrenne","doi":"10.1115/1.4053767","DOIUrl":"https://doi.org/10.1115/1.4053767","url":null,"abstract":"\u0000 A reduced weakly-coupled thermo-mechanical model based on the Proper Generalized Decomposition method was developed for the numerical analysis of power modules. The employed model reduction method enabled to obtain, in a preliminary offline phase, the solution of the thermo-mechanical problem over a large range of design parameters, with much time saving compared to a classical (brute force) multi-resolution finite element method. In an online post-processing phase, the power module lifetime, modeled with a strain-life law, was then computed in a straightforward manner by rapidly evaluating the solution for any value of the parameters. Sensitivity analysis was conducted to select parameters values leading to acceptable module lifetimes with respect to given criteria. A robust design study was also performed to illustrate the performance of the proposed approach.","PeriodicalId":15663,"journal":{"name":"Journal of Electronic Packaging","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41379863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Lall, Jinesh Narangaparambil, Ved Soni, Scott Miller
{"title":"Process-Recipe Development for Printing of Multi-Layer Circuitry with Z-Axis Interconnects Using Aerosol-Jet Printed Dielectric Vias","authors":"P. Lall, Jinesh Narangaparambil, Ved Soni, Scott Miller","doi":"10.1115/1.4053766","DOIUrl":"https://doi.org/10.1115/1.4053766","url":null,"abstract":"\u0000 Flexible electronics is emerging as a new consumer-industry phenomenon. Until now, the work primarily focuses on single-layer printing, taking into account different parameters such as mass flow, line width, sintering conditions, and overspray. The conventional PCBs are multi-layered, and multi-layer stacking of interconnections and establishing z-axis connections through vias similar to conventional PCBs are necessary for the flexible PCB to be used in the real world. Aerosol printing method gives us a broad aspect of establishing the interconnections depending on the various available inks such as silver, copper, carbon etc. Process recipes for manufacturing multilayer circuits and system scale-up methods are required. This paper aims to establish interconnections in the z-axis with the help of Aerosol printable silver ink and dielectric polyimide ink. Formulate process recipes needed to produce multilayer circuits and process scale-up methods. Sintering profile influences the conductivity and shear load value of the printed conductive metal layers requiring process optimization for multilayer builds. The printed conductive lines would undergo different sintering conditions and would then be tested for parameters such as interconnect resistance and shear load to failure. This paper explores the printing of multi-layer up to 8 conductive layers. Sintering profile for lower resistance per unit length and higher shear load to failure was tested.","PeriodicalId":15663,"journal":{"name":"Journal of Electronic Packaging","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45985161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ghazal Mohsenian, C. H. Hoang, K. Nemati, H. Alissa, Mohammad I. Tradat, Najmeh Fallahtafti, Vahideh Radmard, Bruce Murray, B. Sammakia
{"title":"A Novel Design of Rack Mount Server Thermal Simulator: Design, Assembly, and Experimental Verification","authors":"Ghazal Mohsenian, C. H. Hoang, K. Nemati, H. Alissa, Mohammad I. Tradat, Najmeh Fallahtafti, Vahideh Radmard, Bruce Murray, B. Sammakia","doi":"10.1115/1.4053643","DOIUrl":"https://doi.org/10.1115/1.4053643","url":null,"abstract":"\u0000 The practice of commissioning Data Centers (DCs) is necessary to confirm the compliance of the cooling system to the Information Technology Equipment (ITE) load (design capacity). In a typical DC, there are different types of ITE, each having its physical characteristics. Considering these geometrical and internal differences among ITE, it is infeasible to use the actual ITE as a self-simulator. Hence, a separate device called load bank is employed for that purpose. Load banks create a dummy thermal load to analyze, test, and stress the cooling infrastructure. Available commercial load banks do not accurately replicate a server's airflow patterns and transient heat signatures which are governed by thermal inertia, energy dissipation, flow resistance, and fan system behavior. In this study, a novel prototype of the server called server simulator was designed and built with different components to be used as a server mockup. The server simulator accurately captured air resistance, heat dissipation, and the functionality of actual server behavior. Experimental data showed up to 93% improvement in ITE passive and active flow curves using the designed server simulator compared to the commercial load bank. Furthermore, the experimental results demonstrated a below 5% discrepancy on the critical back pressure and free delivery point between the actual ITE and the designed server simulator. In addition, experimental data indicated that the developed server simulator improved the actual ITE thermal mass by 27% compared to the commercial load bank.","PeriodicalId":15663,"journal":{"name":"Journal of Electronic Packaging","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49164284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hayden Carlton, A. Iradukunda, D. Huitink, Sarah Myane, Noah Akey, Asif Imran Emon, Fang Luo
{"title":"Multifunctional Magnetic Nanocomposite Encapsulant for Electromagnetic Interference Shielding in Power Electronics","authors":"Hayden Carlton, A. Iradukunda, D. Huitink, Sarah Myane, Noah Akey, Asif Imran Emon, Fang Luo","doi":"10.1115/1.4053642","DOIUrl":"https://doi.org/10.1115/1.4053642","url":null,"abstract":"\u0000 As power densities and switching frequencies dramatically increase in wide bandgap power electronics, EMI increasingly impacts power conversion efficiency and reliability, which requires mitigation for effective operation. Herein, we propose a nanocomposite encapsulant created by directly incorporating magnetic iron oxide nanoparticles into a silicone matrix for the purpose EMI shielding. The addition of small amounts of particles to the silicone resulted in a 1.7 dBµV drop in EMI intensity; however, the addition of the iron oxide reduced the dielectric breakdown strength of the silicone matrix by 83% with respect to concentration. Further efforts to optimize the dielectric properties of the nanocomposites with respect to the nanoparticle loading is necessary to directly apply this technology; yet the results indicate magnetic nanocomposites could be a potential avenue towards mitigating EMI in power devices.","PeriodicalId":15663,"journal":{"name":"Journal of Electronic Packaging","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45737406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Z. Gao, Tianhu Wang, Yuxin Yang, Xiaolong Shang, Junhua Bai, Peng Li
{"title":"Heat Transfer Analysis of Supercritical Methane in Microchannels with Different Geometric Configurations On High Power Electromechanical Actuator","authors":"Z. Gao, Tianhu Wang, Yuxin Yang, Xiaolong Shang, Junhua Bai, Peng Li","doi":"10.1115/1.4053433","DOIUrl":"https://doi.org/10.1115/1.4053433","url":null,"abstract":"The issue of regenerative cooling is one of the most important key technologies of flight vehicles, which is applied into both the engine and high-power electrical equipment. One pattern of regenerative cooling channels is the microchannel heat sinks, which are thought as a prospective means of improving heat removal capacities on electrical equipment of smaller sizes. In this paper, three numerical models with different geometric configurations, namely straight, zigzag, and sinusoid respectively, are built to probe into the thermal hydraulic performance while heat transfer mechanism of supercritical methane in microchannel heat sinks for the heat removal of high-power electromechanical actuator is also explored. In addition, some crucial influence factors on heat transfer such as inlet Reynolds number, operating pressure and heating power are investigated. The calculation results imply the positive effect of wavy configurations on heat transfer and confirm the important effect of buoyancy force of supercritical methane in channels. The heat sinks with wavy channel show obvious advantages on comprehensive thermal performance including overall thermal performance parameter ? and thermal resistance R compared with that of the straight one. The highest Nu and average heat transfer coefficient am appear in the heat sink with zigzag channels, but the pumping power of the heat sink with sinusoidal channels is lower due to the smaller flow loss.","PeriodicalId":15663,"journal":{"name":"Journal of Electronic Packaging","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44390782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Saini, Pardeep Shahi, Pratik V. Bansode, Jimil M. Shah, D. Agonafer
{"title":"Simplified and Detailed Analysis of Data Center Particulate Contamination At Server and Room Level Using CFD","authors":"S. Saini, Pardeep Shahi, Pratik V. Bansode, Jimil M. Shah, D. Agonafer","doi":"10.1115/1.4053363","DOIUrl":"https://doi.org/10.1115/1.4053363","url":null,"abstract":"\u0000 Continuous rise in cloud computing and other web-based services propelled the data center proliferation seen over the past decade. Traditional data centers use vapor-compression-based cooling units that not only reduce energy efficiency but also increase operational and initial investment costs due to involved redundancies. Free air cooling and airside economization can substantially reduce the IT Equipment (ITE) cooling power consumption, which accounts for approximately 40% of energy consumption for a typical air-cooled data center. However, this cooling approach entails an inherent risk of exposing the IT equipment to harmful ultrafine particulate contaminants, thus, potentially reducing the equipment and component reliability. The present investigation attempts to quantify the effects of particulate contamination inside the data center equipment and ITE room using CFD. An analysis of the boundary conditions to be used was done by detailed modeling of IT equipment and the data center white space. Both 2-D and 3-D simulations were done for detailed analysis of particle transport within the server enclosure. An analysis of the effect of the primary pressure loss obstructions like heat sinks and DIMMs inside the server was done to visualize the localized particle concentrations within the server. A room-level simulation was then conducted to identify the most vulnerable locations of particle concentration within the data center space. The results show that parameters such as higher velocities, heat sink cutouts, and higher aspect ratio features within the server tend to increase the particle concentration inside the servers.","PeriodicalId":15663,"journal":{"name":"Journal of Electronic Packaging","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2021-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42941035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Daiki Saito, K. Sasagawa, T. Moriwaki, K. Fujisaki
{"title":"Damage Analysis in Ag Nanoparticle Interconnect Line Under High-Density Electric Current","authors":"Daiki Saito, K. Sasagawa, T. Moriwaki, K. Fujisaki","doi":"10.1115/1.4053365","DOIUrl":"https://doi.org/10.1115/1.4053365","url":null,"abstract":"\u0000 Printed electronics (PEs) have attracted attention for the fabrication of microscale electronic circuits. PEs use conductive inks which include metal nanoparticles. The conductive ink can be printed on flexible substrates for wearable devices using ink-jet printers and roll-to-roll methods. With the scaling down of electric devices, the current density and Joule heating in the device lines increase, and electromigration (EM) damage becomes significant. EM is a transportation phenomenon of metallic atoms caused by the electron wind under high-density current. Reducing the EM damage is extremely important to enhance the device reliability. With the progress in miniaturization of the metal nanoparticle ink lines, EM problem needs to be solved for ensuring the reliability of these lines. We know that the formation of aggregates and cathode damages occur due to a current loading. The diffusion path of atoms due to the EM has not been identified under the high-density current loading. In this study, a high-density electric current loading was applied to an Ag nanoparticle line. The line specimens were prepared using a lift-off method. After the current loading tests, observations were conducted using a laser microscope and scanning electron microscope. A local decrease in the line thickness and scale-shaped slit-like voids were observed due to the high-density current loading. Moreover, the microstructure of the line was modified by enlarging the Ag grain. From the results, we identified that a dominant diffusion occurred at the Ag grain boundary due to the EM.","PeriodicalId":15663,"journal":{"name":"Journal of Electronic Packaging","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2021-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48217552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}